crypto.c

   1 // TODO key loading, generating, saving
   2 #include "quakedef.h"
   3 #include "crypto.h"
   4 #include "common.h"
   5 #include "thread.h"
   6
   7 #include "hmac.h"
   8 #include "libcurl.h"
   9
  10 cvar_t crypto_developer = {CVAR_SAVE, "crypto_developer", "0", "print extra info about crypto handshake"};
  11 cvar_t crypto_servercpupercent = {CVAR_SAVE, "crypto_servercpupercent", "10", "allowed crypto CPU load in percent for server operation (0 = no limit, faster)"};
  12 cvar_t crypto_servercpumaxtime = {CVAR_SAVE, "crypto_servercpumaxtime", "0.01", "maximum allowed crypto CPU time per frame (0 = no limit)"};
  13 cvar_t crypto_servercpudebug = {CVAR_SAVE, "crypto_servercpudebug", "0", "print statistics about time usage by crypto"};
  14 static double crypto_servercpu_accumulator = 0;
  15 static double crypto_servercpu_lastrealtime = 0;
  16 cvar_t crypto_aeslevel = {CVAR_SAVE, "crypto_aeslevel", "1", "whether to support AES encryption in authenticated connections (0 = no, 1 = supported, 2 = requested, 3 = required)"};
  17 int crypto_keyfp_recommended_length;
  18 static const char *crypto_idstring = NULL;
  19 static char crypto_idstring_buf[512];
  20
  21 #define PROTOCOL_D0_BLIND_ID FOURCC_D0PK
  22 #define PROTOCOL_VLEN (('v' << 0) | ('l' << 8) | ('e' << 16) | ('n' << 24))
  23
  24 // BEGIN stuff shared with crypto-keygen-standalone
  25 #define FOURCC_D0PK (('d' << 0) | ('0' << 8) | ('p' << 16) | ('k' << 24))
  26 #define FOURCC_D0SK (('d' << 0) | ('0' << 8) | ('s' << 16) | ('k' << 24))
  27 #define FOURCC_D0PI (('d' << 0) | ('0' << 8) | ('p' << 16) | ('i' << 24))
  28 #define FOURCC_D0SI (('d' << 0) | ('0' << 8) | ('s' << 16) | ('i' << 24))
  29 #define FOURCC_D0IQ (('d' << 0) | ('0' << 8) | ('i' << 16) | ('q' << 24))
  30 #define FOURCC_D0IR (('d' << 0) | ('0' << 8) | ('i' << 16) | ('r' << 24))
  31 #define FOURCC_D0ER (('d' << 0) | ('0' << 8) | ('e' << 16) | ('r' << 24))
  32 #define FOURCC_D0IC (('d' << 0) | ('0' << 8) | ('i' << 16) | ('c' << 24))
  33
  34 static unsigned long Crypto_LittleLong(const char *data)
  35 {
  36         return
  37                 ((unsigned char) data[0]) |
  38                 (((unsigned char) data[1]) << 8) |
  39                 (((unsigned char) data[2]) << 16) |
  40                 (((unsigned char) data[3]) << 24);
  41 }
  42
  43 static void Crypto_UnLittleLong(char *data, unsigned long l)
  44 {
  45         data[0] = l & 0xFF;
  46         data[1] = (l >> 8) & 0xFF;
  47         data[2] = (l >> 16) & 0xFF;
  48         data[3] = (l >> 24) & 0xFF;
  49 }
  50
  51 static size_t Crypto_ParsePack(const char *buf, size_t len, unsigned long header, const char **lumps, size_t *lumpsize, size_t nlumps)
  52 {
  53         size_t i;
  54         size_t pos;
  55         pos = 0;
  56         if(header)
  57         {
  58                 if(len < 4)
  59                         return 0;
  60                 if(Crypto_LittleLong(buf) != header)
  61                         return 0;
  62                 pos += 4;
  63         }
  64         for(i = 0; i < nlumps; ++i)
  65         {
  66                 if(pos + 4 > len)
  67                         return 0;
  68                 lumpsize[i] = Crypto_LittleLong(&buf[pos]);
  69                 pos += 4;
  70                 if(pos + lumpsize[i] > len)
  71                         return 0;
  72                 lumps[i] = &buf[pos];
  73                 pos += lumpsize[i];
  74         }
  75         return pos;
  76 }
  77
  78 static size_t Crypto_UnParsePack(char *buf, size_t len, unsigned long header, const char *const *lumps, const size_t *lumpsize, size_t nlumps)
  79 {
  80         size_t i;
  81         size_t pos;
  82         pos = 0;
  83         if(header)
  84         {
  85                 if(len < 4)
  86                         return 0;
  87                 Crypto_UnLittleLong(buf, header);
  88                 pos += 4;
  89         }
  90         for(i = 0; i < nlumps; ++i)
  91         {
  92                 if(pos + 4 + lumpsize[i] > len)
  93                         return 0;
  94                 Crypto_UnLittleLong(&buf[pos], lumpsize[i]);
  95                 pos += 4;
  96                 memcpy(&buf[pos], lumps[i], lumpsize[i]);
  97                 pos += lumpsize[i];
  98         }
  99         return pos;
 100 }
 101 // END stuff shared with xonotic-keygen
 102
 103 #define USE_AES
 104
 105 #ifdef CRYPTO_STATIC
 106
 107 #include <d0_blind_id/d0_blind_id.h>
 108
 109 #define d0_blind_id_dll 1
 110 #define Crypto_OpenLibrary() true
 111 #define Crypto_CloseLibrary()
 112
 113 #define qd0_blind_id_new d0_blind_id_new
 114 #define qd0_blind_id_free d0_blind_id_free
 115 //#define qd0_blind_id_clear d0_blind_id_clear
 116 #define qd0_blind_id_copy d0_blind_id_copy
 117 //#define qd0_blind_id_generate_private_key d0_blind_id_generate_private_key
 118 //#define qd0_blind_id_generate_private_key_fastreject d0_blind_id_generate_private_key_fastreject
 119 //#define qd0_blind_id_read_private_key d0_blind_id_read_private_key
 120 #define qd0_blind_id_read_public_key d0_blind_id_read_public_key
 121 //#define qd0_blind_id_write_private_key d0_blind_id_write_private_key
 122 //#define qd0_blind_id_write_public_key d0_blind_id_write_public_key
 123 #define qd0_blind_id_fingerprint64_public_key d0_blind_id_fingerprint64_public_key
 124 //#define qd0_blind_id_generate_private_id_modulus d0_blind_id_generate_private_id_modulus
 125 #define qd0_blind_id_read_private_id_modulus d0_blind_id_read_private_id_modulus
 126 //#define qd0_blind_id_write_private_id_modulus d0_blind_id_write_private_id_modulus
 127 #define qd0_blind_id_generate_private_id_start d0_blind_id_generate_private_id_start
 128 #define qd0_blind_id_generate_private_id_request d0_blind_id_generate_private_id_request
 129 //#define qd0_blind_id_answer_private_id_request d0_blind_id_answer_private_id_request
 130 #define qd0_blind_id_finish_private_id_request d0_blind_id_finish_private_id_request
 131 //#define qd0_blind_id_read_private_id_request_camouflage d0_blind_id_read_private_id_request_camouflage
 132 //#define qd0_blind_id_write_private_id_request_camouflage d0_blind_id_write_private_id_request_camouflage
 133 #define qd0_blind_id_read_private_id d0_blind_id_read_private_id
 134 //#define qd0_blind_id_read_public_id d0_blind_id_read_public_id
 135 #define qd0_blind_id_write_private_id d0_blind_id_write_private_id
 136 //#define qd0_blind_id_write_public_id d0_blind_id_write_public_id
 137 #define qd0_blind_id_authenticate_with_private_id_start d0_blind_id_authenticate_with_private_id_start
 138 #define qd0_blind_id_authenticate_with_private_id_challenge d0_blind_id_authenticate_with_private_id_challenge
 139 #define qd0_blind_id_authenticate_with_private_id_response d0_blind_id_authenticate_with_private_id_response
 140 #define qd0_blind_id_authenticate_with_private_id_verify d0_blind_id_authenticate_with_private_id_verify
 141 #define qd0_blind_id_fingerprint64_public_id d0_blind_id_fingerprint64_public_id
 142 #define qd0_blind_id_sessionkey_public_id d0_blind_id_sessionkey_public_id
 143 #define qd0_blind_id_INITIALIZE d0_blind_id_INITIALIZE
 144 #define qd0_blind_id_SHUTDOWN d0_blind_id_SHUTDOWN
 145 #define qd0_blind_id_util_sha256 d0_blind_id_util_sha256
 146 #define qd0_blind_id_sign_with_private_id_sign d0_blind_id_sign_with_private_id_sign
 147 #define qd0_blind_id_sign_with_private_id_sign_detached d0_blind_id_sign_with_private_id_sign_detached
 148 #define qd0_blind_id_setmallocfuncs d0_blind_id_setmallocfuncs
 149 #define qd0_blind_id_setmutexfuncs d0_blind_id_setmutexfuncs
 150 #define qd0_blind_id_verify_public_id d0_bind_id_verify_public_id
 151 #define qd0_blind_id_verify_private_id d0_bind_id_verify_private_id
 152
 153 #else
 154
 155 // d0_blind_id interface
 156 #define D0_EXPORT
 157 #ifdef __GNUC__
 158 #define D0_WARN_UNUSED_RESULT __attribute__((warn_unused_result))
 159 #else
 160 #define D0_WARN_UNUSED_RESULT
 161 #endif
 162 #define D0_BOOL int
 163
 164 typedef void *(d0_malloc_t)(size_t len);
 165 typedef void (d0_free_t)(void *p);
 166 typedef void *(d0_createmutex_t)(void);
 167 typedef void (d0_destroymutex_t)(void *);
 168 typedef int (d0_lockmutex_t)(void *); // zero on success
 169 typedef int (d0_unlockmutex_t)(void *); // zero on success
 170
 171 typedef struct d0_blind_id_s d0_blind_id_t;
 172 typedef D0_BOOL (*d0_fastreject_function) (const d0_blind_id_t *ctx, void *pass);
 173 static D0_EXPORT D0_WARN_UNUSED_RESULT d0_blind_id_t *(*qd0_blind_id_new) (void);
 174 static D0_EXPORT void (*qd0_blind_id_free) (d0_blind_id_t *a);
 175 //static D0_EXPORT void (*qd0_blind_id_clear) (d0_blind_id_t *ctx);
 176 static D0_EXPORT D0_WARN_UNUSED_RESULT D0_BOOL (*qd0_blind_id_copy) (d0_blind_id_t *ctx, const d0_blind_id_t *src);
 177 //static D0_EXPORT D0_WARN_UNUSED_RESULT D0_BOOL (*qd0_blind_id_generate_private_key) (d0_blind_id_t *ctx, int k);
 178 //static D0_EXPORT D0_WARN_UNUSED_RESULT D0_BOOL (*qd0_blind_id_generate_private_key_fastreject) (d0_blind_id_t *ctx, int k, d0_fastreject_function reject, void *pass);
 179 //static D0_EXPORT D0_WARN_UNUSED_RESULT D0_BOOL (*qd0_blind_id_read_private_key) (d0_blind_id_t *ctx, const char *inbuf, size_t inbuflen);
 180 static D0_EXPORT D0_WARN_UNUSED_RESULT D0_BOOL (*qd0_blind_id_read_public_key) (d0_blind_id_t *ctx, const char *inbuf, size_t inbuflen);
 181 //static D0_EXPORT D0_WARN_UNUSED_RESULT D0_BOOL (*qd0_blind_id_write_private_key) (const d0_blind_id_t *ctx, char *outbuf, size_t *outbuflen);
 182 //static D0_EXPORT D0_WARN_UNUSED_RESULT D0_BOOL (*qd0_blind_id_write_public_key) (const d0_blind_id_t *ctx, char *outbuf, size_t *outbuflen);
 183 static D0_EXPORT D0_WARN_UNUSED_RESULT D0_BOOL (*qd0_blind_id_fingerprint64_public_key) (const d0_blind_id_t *ctx, char *outbuf, size_t *outbuflen);
 184 //static D0_EXPORT D0_WARN_UNUSED_RESULT D0_BOOL (*qd0_blind_id_generate_private_id_modulus) (d0_blind_id_t *ctx);
 185 static D0_EXPORT D0_WARN_UNUSED_RESULT D0_BOOL (*qd0_blind_id_read_private_id_modulus) (d0_blind_id_t *ctx, const char *inbuf, size_t inbuflen);
 186 //static D0_EXPORT D0_WARN_UNUSED_RESULT D0_BOOL (*qd0_blind_id_write_private_id_modulus) (const d0_blind_id_t *ctx, char *outbuf, size_t *outbuflen);
 187 static D0_EXPORT D0_WARN_UNUSED_RESULT D0_BOOL (*qd0_blind_id_generate_private_id_start) (d0_blind_id_t *ctx);
 188 static D0_EXPORT D0_WARN_UNUSED_RESULT D0_BOOL (*qd0_blind_id_generate_private_id_request) (d0_blind_id_t *ctx, char *outbuf, size_t *outbuflen);
 189 //static D0_EXPORT D0_WARN_UNUSED_RESULT D0_BOOL (*qd0_blind_id_answer_private_id_request) (const d0_blind_id_t *ctx, const char *inbuf, size_t inbuflen, char *outbuf, size_t *outbuflen);
 190 static D0_EXPORT D0_WARN_UNUSED_RESULT D0_BOOL (*qd0_blind_id_finish_private_id_request) (d0_blind_id_t *ctx, const char *inbuf, size_t inbuflen);
 191 //static D0_EXPORT D0_WARN_UNUSED_RESULT D0_BOOL (*qd0_blind_id_read_private_id_request_camouflage) (d0_blind_id_t *ctx, const char *inbuf, size_t inbuflen);
 192 //static D0_EXPORT D0_WARN_UNUSED_RESULT D0_BOOL (*qd0_blind_id_write_private_id_request_camouflage) (const d0_blind_id_t *ctx, char *outbuf, size_t *outbuflen);
 193 static D0_EXPORT D0_WARN_UNUSED_RESULT D0_BOOL (*qd0_blind_id_read_private_id) (d0_blind_id_t *ctx, const char *inbuf, size_t inbuflen);
 194 //static D0_EXPORT D0_WARN_UNUSED_RESULT D0_BOOL (*qd0_blind_id_read_public_id) (d0_blind_id_t *ctx, const char *inbuf, size_t inbuflen);
 195 static D0_EXPORT D0_WARN_UNUSED_RESULT D0_BOOL (*qd0_blind_id_write_private_id) (const d0_blind_id_t *ctx, char *outbuf, size_t *outbuflen);
 196 //static D0_EXPORT D0_WARN_UNUSED_RESULT D0_BOOL (*qd0_blind_id_write_public_id) (const d0_blind_id_t *ctx, char *outbuf, size_t *outbuflen);
 197 static D0_EXPORT D0_WARN_UNUSED_RESULT D0_BOOL (*qd0_blind_id_authenticate_with_private_id_start) (d0_blind_id_t *ctx, D0_BOOL is_first, D0_BOOL send_modulus, const char *message, size_t msglen, char *outbuf, size_t *outbuflen);
 198 static D0_EXPORT D0_WARN_UNUSED_RESULT D0_BOOL (*qd0_blind_id_authenticate_with_private_id_challenge) (d0_blind_id_t *ctx, D0_BOOL is_first, D0_BOOL recv_modulus, const char *inbuf, size_t inbuflen, char *outbuf, size_t *outbuflen, D0_BOOL *status);
 199 static D0_EXPORT D0_WARN_UNUSED_RESULT D0_BOOL (*qd0_blind_id_authenticate_with_private_id_response) (d0_blind_id_t *ctx, const char *inbuf, size_t inbuflen, char *outbuf, size_t *outbuflen);
 200 static D0_EXPORT D0_WARN_UNUSED_RESULT D0_BOOL (*qd0_blind_id_authenticate_with_private_id_verify) (d0_blind_id_t *ctx, const char *inbuf, size_t inbuflen, char *msg, size_t *msglen, D0_BOOL *status);
 201 static D0_EXPORT D0_WARN_UNUSED_RESULT D0_BOOL (*qd0_blind_id_fingerprint64_public_id) (const d0_blind_id_t *ctx, char *outbuf, size_t *outbuflen);
 202 static D0_EXPORT D0_WARN_UNUSED_RESULT D0_BOOL (*qd0_blind_id_sessionkey_public_id) (const d0_blind_id_t *ctx, char *outbuf, size_t *outbuflen); // can only be done after successful key exchange, this performs a modpow; key length is limited by SHA_DIGESTSIZE for now; also ONLY valid after successful d0_blind_id_authenticate_with_private_id_verify/d0_blind_id_fingerprint64_public_id
 203 static D0_EXPORT D0_WARN_UNUSED_RESULT D0_BOOL (*qd0_blind_id_INITIALIZE) (void);
 204 static D0_EXPORT void (*qd0_blind_id_SHUTDOWN) (void);
 205 static D0_EXPORT void (*qd0_blind_id_util_sha256) (char *out, const char *in, size_t n);
 206 static D0_EXPORT D0_WARN_UNUSED_RESULT D0_BOOL (*qd0_blind_id_sign_with_private_id_sign) (d0_blind_id_t *ctx, D0_BOOL is_first, D0_BOOL send_modulus, const char *message, size_t msglen, char *outbuf, size_t *outbuflen);
 207 static D0_EXPORT D0_WARN_UNUSED_RESULT D0_BOOL (*qd0_blind_id_sign_with_private_id_sign_detached) (d0_blind_id_t *ctx, D0_BOOL is_first, D0_BOOL send_modulus, const char *message, size_t msglen, char *outbuf, size_t *outbuflen);
 208 static D0_EXPORT void (*qd0_blind_id_setmallocfuncs)(d0_malloc_t *m, d0_free_t *f);
 209 static D0_EXPORT void (*qd0_blind_id_setmutexfuncs)(d0_createmutex_t *c, d0_destroymutex_t *d, d0_lockmutex_t *l, d0_unlockmutex_t *u);
 210 static D0_EXPORT D0_WARN_UNUSED_RESULT D0_BOOL (*qd0_blind_id_verify_public_id)(const d0_blind_id_t *ctx, D0_BOOL *status);
 211 static D0_EXPORT D0_WARN_UNUSED_RESULT D0_BOOL (*qd0_blind_id_verify_private_id)(const d0_blind_id_t *ctx);
 212 static dllfunction_t d0_blind_id_funcs[] =
 213 {
 214         {"d0_blind_id_new", (void **) &qd0_blind_id_new},
 215         {"d0_blind_id_free", (void **) &qd0_blind_id_free},
 216         //{"d0_blind_id_clear", (void **) &qd0_blind_id_clear},
 217         {"d0_blind_id_copy", (void **) &qd0_blind_id_copy},
 218         //{"d0_blind_id_generate_private_key", (void **) &qd0_blind_id_generate_private_key},
 219         //{"d0_blind_id_generate_private_key_fastreject", (void **) &qd0_blind_id_generate_private_key_fastreject},
 220         //{"d0_blind_id_read_private_key", (void **) &qd0_blind_id_read_private_key},
 221         {"d0_blind_id_read_public_key", (void **) &qd0_blind_id_read_public_key},
 222         //{"d0_blind_id_write_private_key", (void **) &qd0_blind_id_write_private_key},
 223         //{"d0_blind_id_write_public_key", (void **) &qd0_blind_id_write_public_key},
 224         {"d0_blind_id_fingerprint64_public_key", (void **) &qd0_blind_id_fingerprint64_public_key},
 225         //{"d0_blind_id_generate_private_id_modulus", (void **) &qd0_blind_id_generate_private_id_modulus},
 226         {"d0_blind_id_read_private_id_modulus", (void **) &qd0_blind_id_read_private_id_modulus},
 227         //{"d0_blind_id_write_private_id_modulus", (void **) &qd0_blind_id_write_private_id_modulus},
 228         {"d0_blind_id_generate_private_id_start", (void **) &qd0_blind_id_generate_private_id_start},
 229         {"d0_blind_id_generate_private_id_request", (void **) &qd0_blind_id_generate_private_id_request},
 230         //{"d0_blind_id_answer_private_id_request", (void **) &qd0_blind_id_answer_private_id_request},
 231         {"d0_blind_id_finish_private_id_request", (void **) &qd0_blind_id_finish_private_id_request},
 232         //{"d0_blind_id_read_private_id_request_camouflage", (void **) &qd0_blind_id_read_private_id_request_camouflage},
 233         //{"d0_blind_id_write_private_id_request_camouflage", (void **) &qd0_blind_id_write_private_id_request_camouflage},
 234         {"d0_blind_id_read_private_id", (void **) &qd0_blind_id_read_private_id},
 235         //{"d0_blind_id_read_public_id", (void **) &qd0_blind_id_read_public_id},
 236         {"d0_blind_id_write_private_id", (void **) &qd0_blind_id_write_private_id},
 237         //{"d0_blind_id_write_public_id", (void **) &qd0_blind_id_write_public_id},
 238         {"d0_blind_id_authenticate_with_private_id_start", (void **) &qd0_blind_id_authenticate_with_private_id_start},
 239         {"d0_blind_id_authenticate_with_private_id_challenge", (void **) &qd0_blind_id_authenticate_with_private_id_challenge},
 240         {"d0_blind_id_authenticate_with_private_id_response", (void **) &qd0_blind_id_authenticate_with_private_id_response},
 241         {"d0_blind_id_authenticate_with_private_id_verify", (void **) &qd0_blind_id_authenticate_with_private_id_verify},
 242         {"d0_blind_id_fingerprint64_public_id", (void **) &qd0_blind_id_fingerprint64_public_id},
 243         {"d0_blind_id_sessionkey_public_id", (void **) &qd0_blind_id_sessionkey_public_id},
 244         {"d0_blind_id_INITIALIZE", (void **) &qd0_blind_id_INITIALIZE},
 245         {"d0_blind_id_SHUTDOWN", (void **) &qd0_blind_id_SHUTDOWN},
 246         {"d0_blind_id_util_sha256", (void **) &qd0_blind_id_util_sha256},
 247         {"d0_blind_id_sign_with_private_id_sign", (void **) &qd0_blind_id_sign_with_private_id_sign},
 248         {"d0_blind_id_sign_with_private_id_sign_detached", (void **) &qd0_blind_id_sign_with_private_id_sign_detached},
 249         {"d0_blind_id_setmallocfuncs", (void **) &qd0_blind_id_setmallocfuncs},
 250         {"d0_blind_id_setmutexfuncs", (void **) &qd0_blind_id_setmutexfuncs},
 251         {"d0_blind_id_verify_public_id", (void **) &qd0_blind_id_verify_public_id},
 252         {"d0_blind_id_verify_private_id", (void **) &qd0_blind_id_verify_private_id},
 253         {NULL, NULL}
 254 };
 255 // end of d0_blind_id interface
 256
 257 static dllhandle_t d0_blind_id_dll = NULL;
 258 static qboolean Crypto_OpenLibrary (void)
 259 {
 260         const char* dllnames [] =
 261         {
 262 #if defined(WIN32)
 263                 "libd0_blind_id-0.dll",
 264 #elif defined(MACOSX)
 265                 "libd0_blind_id.0.dylib",
 266 #else
 267                 "libd0_blind_id.so.0",
 268                 "libd0_blind_id.so", // FreeBSD
 269 #endif
 270                 NULL
 271         };
 272
 273         // Already loaded?
 274         if (d0_blind_id_dll)
 275                 return true;
 276
 277         // Load the DLL
 278         return Sys_LoadLibrary (dllnames, &d0_blind_id_dll, d0_blind_id_funcs);
 279 }
 280
 281 static void Crypto_CloseLibrary (void)
 282 {
 283         Sys_UnloadLibrary (&d0_blind_id_dll);
 284 }
 285
 286 #endif
 287
 288 #ifdef CRYPTO_RIJNDAEL_STATIC
 289
 290 #include <d0_blind_id/d0_rijndael.h>
 291
 292 #define d0_rijndael_dll 1
 293 #define Crypto_Rijndael_OpenLibrary() true
 294 #define Crypto_Rijndael_CloseLibrary()
 295
 296 #define qd0_rijndael_setup_encrypt d0_rijndael_setup_encrypt
 297 #define qd0_rijndael_setup_decrypt d0_rijndael_setup_decrypt
 298 #define qd0_rijndael_encrypt d0_rijndael_encrypt
 299 #define qd0_rijndael_decrypt d0_rijndael_decrypt
 300
 301 #else
 302
 303 // no need to do the #define dance here, as the upper part declares out macros either way
 304
 305 D0_EXPORT int (*qd0_rijndael_setup_encrypt) (unsigned long *rk, const unsigned char *key,
 306   int keybits);
 307 D0_EXPORT int (*qd0_rijndael_setup_decrypt) (unsigned long *rk, const unsigned char *key,
 308   int keybits);
 309 D0_EXPORT void (*qd0_rijndael_encrypt) (const unsigned long *rk, int nrounds,
 310   const unsigned char plaintext[16], unsigned char ciphertext[16]);
 311 D0_EXPORT void (*qd0_rijndael_decrypt) (const unsigned long *rk, int nrounds,
 312   const unsigned char ciphertext[16], unsigned char plaintext[16]);
 313 #define D0_RIJNDAEL_KEYLENGTH(keybits) ((keybits)/8)
 314 #define D0_RIJNDAEL_RKLENGTH(keybits)  ((keybits)/8+28)
 315 #define D0_RIJNDAEL_NROUNDS(keybits)   ((keybits)/32+6)
 316 static dllfunction_t d0_rijndael_funcs[] =
 317 {
 318         {"d0_rijndael_setup_decrypt", (void **) &qd0_rijndael_setup_decrypt},
 319         {"d0_rijndael_setup_encrypt", (void **) &qd0_rijndael_setup_encrypt},
 320         {"d0_rijndael_decrypt", (void **) &qd0_rijndael_decrypt},
 321         {"d0_rijndael_encrypt", (void **) &qd0_rijndael_encrypt},
 322         {NULL, NULL}
 323 };
 324 // end of d0_blind_id interface
 325
 326 static dllhandle_t d0_rijndael_dll = NULL;
 327 static qboolean Crypto_Rijndael_OpenLibrary (void)
 328 {
 329         const char* dllnames [] =
 330         {
 331 #if defined(WIN32)
 332                 "libd0_rijndael-0.dll",
 333 #elif defined(MACOSX)
 334                 "libd0_rijndael.0.dylib",
 335 #else
 336                 "libd0_rijndael.so.0",
 337                 "libd0_rijndael.so", // FreeBSD
 338 #endif
 339                 NULL
 340         };
 341
 342         // Already loaded?
 343         if (d0_rijndael_dll)
 344                 return true;
 345
 346         // Load the DLL
 347         return Sys_LoadLibrary (dllnames, &d0_rijndael_dll, d0_rijndael_funcs);
 348 }
 349
 350 static void Crypto_Rijndael_CloseLibrary (void)
 351 {
 352         Sys_UnloadLibrary (&d0_rijndael_dll);
 353 }
 354
 355 #endif
 356
 357 // various helpers
 358 void sha256(unsigned char *out, const unsigned char *in, int n)
 359 {
 360         qd0_blind_id_util_sha256((char *) out, (const char *) in, n);
 361 }
 362
 363 static size_t Crypto_LoadFile(const char *path, char *buf, size_t nmax, qboolean inuserdir)
 364 {
 365         char vabuf[1024];
 366         qfile_t *f = NULL;
 367         fs_offset_t n;
 368         if(inuserdir)
 369                 f = FS_SysOpen(va(vabuf, sizeof(vabuf), "%s%s", *fs_userdir ? fs_userdir : fs_basedir, path), "rb", false);
 370         else
 371                 f = FS_SysOpen(va(vabuf, sizeof(vabuf), "%s%s", fs_basedir, path), "rb", false);
 372         if(!f)
 373                 return 0;
 374         n = FS_Read(f, buf, nmax);
 375         if(n < 0)
 376                 n = 0;
 377         FS_Close(f);
 378         return (size_t) n;
 379 }
 380
 381 static qboolean PutWithNul(char **data, size_t *len, const char *str)
 382 {
 383         // invariant: data points to insertion point
 384         size_t l = strlen(str);
 385         if(l >= *len)
 386                 return false;
 387         memcpy(*data, str, l+1);
 388         *data += l+1;
 389         *len -= l+1;
 390         return true;
 391 }
 392
 393 static const char *GetUntilNul(const char **data, size_t *len)
 394 {
 395         // invariant: data points to next character to take
 396         const char *data_save = *data;
 397         size_t n;
 398         const char *p;
 399
 400         if(!*data)
 401                 return NULL;
 402
 403         if(!*len)
 404         {
 405                 *data = NULL;
 406                 return NULL;
 407         }
 408
 409         p = (const char *) memchr(*data, 0, *len);
 410         if(!p) // no terminating NUL
 411         {
 412                 *data = NULL;
 413                 *len = 0;
 414                 return NULL;
 415         }
 416         else
 417         {
 418                 n = (p - *data) + 1;
 419                 *len -= n;
 420                 *data += n;
 421                 if(*len == 0)
 422                         *data = NULL;
 423                 return (const char *) data_save;
 424         }
 425         *data = NULL;
 426         return NULL;
 427 }
 428
 429 // d0pk reading
 430 static d0_blind_id_t *Crypto_ReadPublicKey(char *buf, size_t len)
 431 {
 432         d0_blind_id_t *pk = NULL;
 433         const char *p[2];
 434         size_t l[2];
 435         if(Crypto_ParsePack(buf, len, FOURCC_D0PK, p, l, 2))
 436         {
 437                 pk = qd0_blind_id_new();
 438                 if(pk)
 439                         if(qd0_blind_id_read_public_key(pk, p[0], l[0]))
 440                                 if(qd0_blind_id_read_private_id_modulus(pk, p[1], l[1]))
 441                                         return pk;
 442         }
 443         if(pk)
 444                 qd0_blind_id_free(pk);
 445         return NULL;
 446 }
 447
 448 // d0si reading
 449 static qboolean Crypto_AddPrivateKey(d0_blind_id_t *pk, char *buf, size_t len)
 450 {
 451         const char *p[1];
 452         size_t l[1];
 453         if(Crypto_ParsePack(buf, len, FOURCC_D0SI, p, l, 1))
 454         {
 455                 if(qd0_blind_id_read_private_id(pk, p[0], l[0]))
 456                         return true;
 457         }
 458         return false;
 459 }
 460
 461 #define MAX_PUBKEYS 16
 462 static d0_blind_id_t *pubkeys[MAX_PUBKEYS];
 463 static char pubkeys_fp64[MAX_PUBKEYS][FP64_SIZE+1];
 464 static qboolean pubkeys_havepriv[MAX_PUBKEYS];
 465 static qboolean pubkeys_havesig[MAX_PUBKEYS];
 466 static char pubkeys_priv_fp64[MAX_PUBKEYS][FP64_SIZE+1];
 467 static char challenge_append[1400];
 468 static size_t challenge_append_length;
 469
 470 static int keygen_i = -1;
 471 static char keygen_buf[8192];
 472
 473 #define MAX_CRYPTOCONNECTS 16
 474 #define CRYPTOCONNECT_NONE 0
 475 #define CRYPTOCONNECT_PRECONNECT 1
 476 #define CRYPTOCONNECT_CONNECT 2
 477 #define CRYPTOCONNECT_RECONNECT 3
 478 #define CRYPTOCONNECT_DUPLICATE 4
 479 typedef struct server_cryptoconnect_s
 480 {
 481         double lasttime;
 482         lhnetaddress_t address;
 483         crypto_t crypto;
 484         int next_step;
 485 }
 486 server_cryptoconnect_t;
 487 static server_cryptoconnect_t cryptoconnects[MAX_CRYPTOCONNECTS];
 488
 489 static int cdata_id = 0;
 490 typedef struct
 491 {
 492         d0_blind_id_t *id;
 493         int s, c;
 494         int next_step;
 495         char challenge[2048];
 496         char wantserver_idfp[FP64_SIZE+1];
 497         qboolean wantserver_aes;
 498         int cdata_id;
 499 }
 500 crypto_data_t;
 501
 502 // crypto specific helpers
 503 #define CDATA ((crypto_data_t *) crypto->data)
 504 #define MAKE_CDATA if(!crypto->data) crypto->data = Z_Malloc(sizeof(crypto_data_t))
 505 #define CLEAR_CDATA if(crypto->data) { if(CDATA->id) qd0_blind_id_free(CDATA->id); Z_Free(crypto->data); } crypto->data = NULL
 506
 507 static crypto_t *Crypto_ServerFindInstance(lhnetaddress_t *peeraddress, qboolean allow_create)
 508 {
 509         crypto_t *crypto;
 510         int i, best;
 511
 512         if(!d0_blind_id_dll)
 513                 return NULL; // no support
 514
 515         for(i = 0; i < MAX_CRYPTOCONNECTS; ++i)
 516                 if(LHNETADDRESS_Compare(peeraddress, &cryptoconnects[i].address))
 517                         break;
 518         if(i < MAX_CRYPTOCONNECTS && (allow_create || cryptoconnects[i].crypto.data))
 519         {
 520                 crypto = &cryptoconnects[i].crypto;
 521                 cryptoconnects[i].lasttime = realtime;
 522                 return crypto;
 523         }
 524         if(!allow_create)
 525                 return NULL;
 526         best = 0;
 527         for(i = 1; i < MAX_CRYPTOCONNECTS; ++i)
 528                 if(cryptoconnects[i].lasttime < cryptoconnects[best].lasttime)
 529                         best = i;
 530         crypto = &cryptoconnects[best].crypto;
 531         cryptoconnects[best].lasttime = realtime;
 532         memcpy(&cryptoconnects[best].address, peeraddress, sizeof(cryptoconnects[best].address));
 533         CLEAR_CDATA;
 534         return crypto;
 535 }
 536
 537 qboolean Crypto_ServerFinishInstance(crypto_t *out, crypto_t *crypto)
 538 {
 539         // no check needed here (returned pointers are only used in prefilled fields)
 540         if(!crypto || !crypto->authenticated)
 541         {
 542                 Con_Printf("Passed an invalid crypto connect instance\n");
 543                 memset(out, 0, sizeof(*out));
 544                 return false;
 545         }
 546         CLEAR_CDATA;
 547         memcpy(out, crypto, sizeof(*out));
 548         memset(crypto, 0, sizeof(crypto));
 549         return true;
 550 }
 551
 552 crypto_t *Crypto_ServerGetInstance(lhnetaddress_t *peeraddress)
 553 {
 554         // no check needed here (returned pointers are only used in prefilled fields)
 555         return Crypto_ServerFindInstance(peeraddress, false);
 556 }
 557
 558 typedef struct crypto_storedhostkey_s
 559 {
 560         struct crypto_storedhostkey_s *next;
 561         lhnetaddress_t addr;
 562         int keyid;
 563         char idfp[FP64_SIZE+1];
 564         int aeslevel;
 565 }
 566 crypto_storedhostkey_t;
 567 static crypto_storedhostkey_t *crypto_storedhostkey_hashtable[CRYPTO_HOSTKEY_HASHSIZE];
 568
 569 static void Crypto_InitHostKeys(void)
 570 {
 571         int i;
 572         for(i = 0; i < CRYPTO_HOSTKEY_HASHSIZE; ++i)
 573                 crypto_storedhostkey_hashtable[i] = NULL;
 574 }
 575
 576 static void Crypto_ClearHostKeys(void)
 577 {
 578         int i;
 579         crypto_storedhostkey_t *hk, *hkn;
 580         for(i = 0; i < CRYPTO_HOSTKEY_HASHSIZE; ++i)
 581         {
 582                 for(hk = crypto_storedhostkey_hashtable[i]; hk; hk = hkn)
 583                 {
 584                         hkn = hk->next;
 585                         Z_Free(hk);
 586                 }
 587                 crypto_storedhostkey_hashtable[i] = NULL;
 588         }
 589 }
 590
 591 static qboolean Crypto_ClearHostKey(lhnetaddress_t *peeraddress)
 592 {
 593         char buf[128];
 594         int hashindex;
 595         crypto_storedhostkey_t **hkp;
 596         qboolean found = false;
 597
 598         LHNETADDRESS_ToString(peeraddress, buf, sizeof(buf), 1);
 599         hashindex = CRC_Block((const unsigned char *) buf, strlen(buf)) % CRYPTO_HOSTKEY_HASHSIZE;
 600         for(hkp = &crypto_storedhostkey_hashtable[hashindex]; *hkp && LHNETADDRESS_Compare(&((*hkp)->addr), peeraddress); hkp = &((*hkp)->next));
 601
 602         if(*hkp)
 603         {
 604                 crypto_storedhostkey_t *hk = *hkp;
 605                 *hkp = hk->next;
 606                 Z_Free(hk);
 607                 found = true;
 608         }
 609
 610         return found;
 611 }
 612
 613 static void Crypto_StoreHostKey(lhnetaddress_t *peeraddress, const char *keystring, qboolean complain)
 614 {
 615         char buf[128];
 616         int hashindex;
 617         crypto_storedhostkey_t *hk;
 618         int keyid;
 619         char idfp[FP64_SIZE+1];
 620         int aeslevel;
 621
 622         if(!d0_blind_id_dll)
 623                 return;
 624
 625         // syntax of keystring:
 626         // aeslevel id@key id@key ...
 627
 628         if(!*keystring)
 629                 return;
 630         aeslevel = bound(0, *keystring - '0', 3);
 631         while(*keystring && *keystring != ' ')
 632                 ++keystring;
 633
 634         keyid = -1;
 635         while(*keystring && keyid < 0)
 636         {
 637                 // id@key
 638                 const char *idstart, *idend, *keystart, *keyend;
 639                 ++keystring; // skip the space
 640                 idstart = keystring;
 641                 while(*keystring && *keystring != ' ' && *keystring != '@')
 642                         ++keystring;
 643                 idend = keystring;
 644                 if(!*keystring)
 645                         break;
 646                 ++keystring;
 647                 keystart = keystring;
 648                 while(*keystring && *keystring != ' ')
 649                         ++keystring;
 650                 keyend = keystring;
 651
 652                 if(idend - idstart == FP64_SIZE && keyend - keystart == FP64_SIZE)
 653                 {
 654                         for(keyid = 0; keyid < MAX_PUBKEYS; ++keyid)
 655                                 if(pubkeys[keyid])
 656                                         if(!memcmp(pubkeys_fp64[keyid], keystart, FP64_SIZE))
 657                                         {
 658                                                 memcpy(idfp, idstart, FP64_SIZE);
 659                                                 idfp[FP64_SIZE] = 0;
 660                                                 break;
 661                                         }
 662                         if(keyid >= MAX_PUBKEYS)
 663                                 keyid = -1;
 664                 }
 665         }
 666
 667         if(keyid < 0)
 668                 return;
 669
 670         LHNETADDRESS_ToString(peeraddress, buf, sizeof(buf), 1);
 671         hashindex = CRC_Block((const unsigned char *) buf, strlen(buf)) % CRYPTO_HOSTKEY_HASHSIZE;
 672         for(hk = crypto_storedhostkey_hashtable[hashindex]; hk && LHNETADDRESS_Compare(&hk->addr, peeraddress); hk = hk->next);
 673
 674         if(hk)
 675         {
 676                 if(complain)
 677                 {
 678                         if(hk->keyid != keyid || memcmp(hk->idfp, idfp, FP64_SIZE+1))
 679                                 Con_Printf("Server %s tried to change the host key to a value not in the host cache. Connecting to it will fail. To accept the new host key, do crypto_hostkey_clear %s\n", buf, buf);
 680                         if(hk->aeslevel > aeslevel)
 681                                 Con_Printf("Server %s tried to reduce encryption status, not accepted. Connecting to it will fail. To accept, do crypto_hostkey_clear %s\n", buf, buf);
 682                 }
 683                 hk->aeslevel = max(aeslevel, hk->aeslevel);
 684                 return;
 685         }
 686
 687         // great, we did NOT have it yet
 688         hk = (crypto_storedhostkey_t *) Z_Malloc(sizeof(*hk));
 689         memcpy(&hk->addr, peeraddress, sizeof(hk->addr));
 690         hk->keyid = keyid;
 691         memcpy(hk->idfp, idfp, FP64_SIZE+1);
 692         hk->next = crypto_storedhostkey_hashtable[hashindex];
 693         hk->aeslevel = aeslevel;
 694         crypto_storedhostkey_hashtable[hashindex] = hk;
 695 }
 696
 697 qboolean Crypto_RetrieveHostKey(lhnetaddress_t *peeraddress, int *keyid, char *keyfp, size_t keyfplen, char *idfp, size_t idfplen, int *aeslevel)
 698 {
 699         char buf[128];
 700         int hashindex;
 701         crypto_storedhostkey_t *hk;
 702
 703         if(!d0_blind_id_dll)
 704                 return false;
 705
 706         LHNETADDRESS_ToString(peeraddress, buf, sizeof(buf), 1);
 707         hashindex = CRC_Block((const unsigned char *) buf, strlen(buf)) % CRYPTO_HOSTKEY_HASHSIZE;
 708         for(hk = crypto_storedhostkey_hashtable[hashindex]; hk && LHNETADDRESS_Compare(&hk->addr, peeraddress); hk = hk->next);
 709
 710         if(!hk)
 711                 return false;
 712
 713         if(keyid)
 714                 *keyid = hk->keyid;
 715         if(keyfp)
 716                 strlcpy(keyfp, pubkeys_fp64[hk->keyid], keyfplen);
 717         if(idfp)
 718                 strlcpy(idfp, hk->idfp, idfplen);
 719         if(aeslevel)
 720                 *aeslevel = hk->aeslevel;
 721
 722         return true;
 723 }
 724 int Crypto_RetrieveLocalKey(int keyid, char *keyfp, size_t keyfplen, char *idfp, size_t idfplen, qboolean *issigned) // return value: -1 if more to come, +1 if valid, 0 if end of list
 725 {
 726         if(keyid < 0 || keyid >= MAX_PUBKEYS)
 727                 return 0;
 728         if(keyfp)
 729                 *keyfp = 0;
 730         if(idfp)
 731                 *idfp = 0;
 732         if(!pubkeys[keyid])
 733                 return -1;
 734         if(keyfp)
 735                 strlcpy(keyfp, pubkeys_fp64[keyid], keyfplen);
 736         if(idfp)
 737                 if(pubkeys_havepriv[keyid])
 738                         strlcpy(idfp, pubkeys_priv_fp64[keyid], keyfplen);
 739         if(issigned)
 740                 *issigned = pubkeys_havesig[keyid];
 741         return 1;
 742 }
 743 // end
 744
 745 // init/shutdown code
 746 static void Crypto_BuildChallengeAppend(void)
 747 {
 748         char *p, *lengthptr, *startptr;
 749         size_t n;
 750         int i;
 751         p = challenge_append;
 752         n = sizeof(challenge_append);
 753         Crypto_UnLittleLong(p, PROTOCOL_VLEN);
 754         p += 4;
 755         n -= 4;
 756         lengthptr = p;
 757         Crypto_UnLittleLong(p, 0);
 758         p += 4;
 759         n -= 4;
 760         Crypto_UnLittleLong(p, PROTOCOL_D0_BLIND_ID);
 761         p += 4;
 762         n -= 4;
 763         startptr = p;
 764         for(i = 0; i < MAX_PUBKEYS; ++i)
 765                 if(pubkeys_havepriv[i])
 766                         PutWithNul(&p, &n, pubkeys_fp64[i]);
 767         PutWithNul(&p, &n, "");
 768         for(i = 0; i < MAX_PUBKEYS; ++i)
 769                 if(!pubkeys_havepriv[i] && pubkeys[i])
 770                         PutWithNul(&p, &n, pubkeys_fp64[i]);
 771         Crypto_UnLittleLong(lengthptr, p - startptr);
 772         challenge_append_length = p - challenge_append;
 773 }
 774
 775 void Crypto_LoadKeys(void)
 776 {
 777         char buf[8192];
 778         size_t len, len2;
 779         int i;
 780         char vabuf[1024];
 781
 782         if(!d0_blind_id_dll) // don't if we can't
 783                 return;
 784
 785         if(crypto_idstring) // already loaded? then not
 786                 return;
 787
 788         Host_LockSession(); // we use the session ID here
 789
 790         // load keys
 791         // note: we are just a CLIENT
 792         // so we load:
 793         //   PUBLIC KEYS to accept (including modulus)
 794         //   PRIVATE KEY of user
 795
 796         crypto_idstring = NULL;
 797         dpsnprintf(crypto_idstring_buf, sizeof(crypto_idstring_buf), "%d", d0_rijndael_dll ? crypto_aeslevel.integer : 0);
 798         for(i = 0; i < MAX_PUBKEYS; ++i)
 799         {
 800                 memset(pubkeys_fp64[i], 0, sizeof(pubkeys_fp64[i]));
 801                 memset(pubkeys_priv_fp64[i], 0, sizeof(pubkeys_fp64[i]));
 802                 pubkeys_havepriv[i] = false;
 803                 pubkeys_havesig[i] = false;
 804                 len = Crypto_LoadFile(va(vabuf, sizeof(vabuf), "key_%d.d0pk", i), buf, sizeof(buf), false);
 805                 if((pubkeys[i] = Crypto_ReadPublicKey(buf, len)))
 806                 {
 807                         len2 = FP64_SIZE;
 808                         if(qd0_blind_id_fingerprint64_public_key(pubkeys[i], pubkeys_fp64[i], &len2)) // keeps final NUL
 809                         {
 810                                 Con_Printf("Loaded public key key_%d.d0pk (fingerprint: %s)\n", i, pubkeys_fp64[i]);
 811                                 len = Crypto_LoadFile(va(vabuf, sizeof(vabuf), "key_%d.d0si%s", i, sessionid.string), buf, sizeof(buf), true);
 812                                 if(len)
 813                                 {
 814                                         if(Crypto_AddPrivateKey(pubkeys[i], buf, len))
 815                                         {
 816                                                 len2 = FP64_SIZE;
 817                                                 if(qd0_blind_id_fingerprint64_public_id(pubkeys[i], pubkeys_priv_fp64[i], &len2)) // keeps final NUL
 818                                                 {
 819                                                         D0_BOOL status = 0;
 820                                                         qfile_t *f;
 821
 822                                                         Con_Printf("Loaded private ID key_%d.d0si%s for key_%d.d0pk (public key fingerprint: %s)\n", i, sessionid.string, i, pubkeys_priv_fp64[i]);
 823
 824                                                         f = FS_SysOpen(va(vabuf, sizeof(vabuf), "%skey_%d-public-fp%s.txt", *fs_userdir ? fs_userdir : fs_basedir, i, sessionid.string), "w", false);
 825                                                         if(f)
 826                                                         {
 827                                                                 // we ignore errors for this file, as it's not necessary to have
 828                                                                 FS_Write(f, pubkeys_priv_fp64[i], FP64_SIZE);
 829                                                                 FS_Write(f, "\n", 1);
 830                                                                 FS_Close(f);
 831                                                         }
 832
 833                                                         // verify the key we just loaded (just in case)
 834                                                         if(qd0_blind_id_verify_private_id(pubkeys[i]) && qd0_blind_id_verify_public_id(pubkeys[i], &status))
 835                                                         {
 836                                                                 pubkeys_havepriv[i] = true;
 837                                                                 strlcat(crypto_idstring_buf, va(vabuf, sizeof(vabuf), " %s@%s", pubkeys_priv_fp64[i], pubkeys_fp64[i]), sizeof(crypto_idstring_buf));
 838
 839                                                                 // verify the key we just got (just in case)
 840                                                                 if(status)
 841                                                                         pubkeys_havesig[i] = true;
 842                                                                 else
 843                                                                         Con_Printf("NOTE: this ID has not yet been signed!\n");
 844                                                         }
 845                                                         else
 846                                                         {
 847                                                                 Con_Printf("d0_blind_id_verify_private_id failed, this is not a valid key!\n");
 848                                                                 qd0_blind_id_free(pubkeys[i]);
 849                                                                 pubkeys[i] = NULL;
 850                                                         }
 851                                                 }
 852                                                 else
 853                                                 {
 854                                                         Con_Printf("d0_blind_id_fingerprint64_public_id failed\n");
 855                                                         qd0_blind_id_free(pubkeys[i]);
 856                                                         pubkeys[i] = NULL;
 857                                                 }
 858                                         }
 859                                 }
 860                         }
 861                         else
 862                         {
 863                                 // can't really happen
 864                                 qd0_blind_id_free(pubkeys[i]);
 865                                 pubkeys[i] = NULL;
 866                         }
 867                 }
 868         }
 869         crypto_idstring = crypto_idstring_buf;
 870
 871         keygen_i = -1;
 872         Crypto_BuildChallengeAppend();
 873
 874         // find a good prefix length for all the keys we know (yes, algorithm is not perfect yet, may yield too long prefix length)
 875         crypto_keyfp_recommended_length = 0;
 876         memset(buf+256, 0, MAX_PUBKEYS + MAX_PUBKEYS);
 877         while(crypto_keyfp_recommended_length < FP64_SIZE)
 878         {
 879                 memset(buf, 0, 256);
 880                 for(i = 0; i < MAX_PUBKEYS; ++i)
 881                         if(pubkeys[i])
 882                         {
 883                                 if(!buf[256 + i])
 884                                         ++buf[(unsigned char) pubkeys_fp64[i][crypto_keyfp_recommended_length]];
 885                                 if(pubkeys_havepriv[i])
 886                                         if(!buf[256 + MAX_PUBKEYS + i])
 887                                                 ++buf[(unsigned char) pubkeys_priv_fp64[i][crypto_keyfp_recommended_length]];
 888                         }
 889                 for(i = 0; i < MAX_PUBKEYS; ++i)
 890                         if(pubkeys[i])
 891                         {
 892                                 if(!buf[256 + i])
 893                                         if(buf[(unsigned char) pubkeys_fp64[i][crypto_keyfp_recommended_length]] < 2)
 894                                                 buf[256 + i] = 1;
 895                                 if(pubkeys_havepriv[i])
 896                                         if(!buf[256 + MAX_PUBKEYS + i])
 897                                                 if(buf[(unsigned char) pubkeys_priv_fp64[i][crypto_keyfp_recommended_length]] < 2)
 898                                                         buf[256 + MAX_PUBKEYS + i] = 1;
 899                         }
 900                 ++crypto_keyfp_recommended_length;
 901                 for(i = 0; i < MAX_PUBKEYS; ++i)
 902                         if(pubkeys[i])
 903                         {
 904                                 if(!buf[256 + i])
 905                                         break;
 906                                 if(pubkeys_havepriv[i])
 907                                         if(!buf[256 + MAX_PUBKEYS + i])
 908                                                 break;
 909                         }
 910                 if(i >= MAX_PUBKEYS)
 911                         break;
 912         }
 913         if(crypto_keyfp_recommended_length < 7)
 914                 crypto_keyfp_recommended_length = 7;
 915 }
 916
 917 static void Crypto_UnloadKeys(void)
 918 {
 919         int i;
 920
 921         keygen_i = -1;
 922         for(i = 0; i < MAX_PUBKEYS; ++i)
 923         {
 924                 if(pubkeys[i])
 925                         qd0_blind_id_free(pubkeys[i]);
 926                 pubkeys[i] = NULL;
 927                 pubkeys_havepriv[i] = false;
 928                 pubkeys_havesig[i] = false;
 929                 memset(pubkeys_fp64[i], 0, sizeof(pubkeys_fp64[i]));
 930                 memset(pubkeys_priv_fp64[i], 0, sizeof(pubkeys_fp64[i]));
 931                 challenge_append_length = 0;
 932         }
 933         crypto_idstring = NULL;
 934 }
 935
 936 static mempool_t *cryptomempool;
 937
 938 #ifdef __cplusplus
 939 extern "C"
 940 {
 941 #endif
 942 static void *Crypto_d0_malloc(size_t len)
 943 {
 944         return Mem_Alloc(cryptomempool, len);
 945 }
 946
 947 static void Crypto_d0_free(void *p)
 948 {
 949         Mem_Free(p);
 950 }
 951
 952 static void *Crypto_d0_createmutex(void)
 953 {
 954         return Thread_CreateMutex();
 955 }
 956
 957 static void Crypto_d0_destroymutex(void *m)
 958 {
 959         Thread_DestroyMutex(m);
 960 }
 961
 962 static int Crypto_d0_lockmutex(void *m)
 963 {
 964         return Thread_LockMutex(m);
 965 }
 966
 967 static int Crypto_d0_unlockmutex(void *m)
 968 {
 969         return Thread_UnlockMutex(m);
 970 }
 971 #ifdef __cplusplus
 972 }
 973 #endif
 974
 975 void Crypto_Shutdown(void)
 976 {
 977         crypto_t *crypto;
 978         int i;
 979
 980         Crypto_Rijndael_CloseLibrary();
 981
 982         if(d0_blind_id_dll)
 983         {
 984                 // free memory
 985                 for(i = 0; i < MAX_CRYPTOCONNECTS; ++i)
 986                 {
 987                         crypto = &cryptoconnects[i].crypto;
 988                         CLEAR_CDATA;
 989                 }
 990                 memset(cryptoconnects, 0, sizeof(cryptoconnects));
 991                 crypto = &cls.crypto;
 992                 CLEAR_CDATA;
 993
 994                 Crypto_UnloadKeys();
 995
 996                 qd0_blind_id_SHUTDOWN();
 997
 998                 Crypto_CloseLibrary();
 999         }
1000
1001         Mem_FreePool(&cryptomempool);
1002 }
1003
1004 void Crypto_Init(void)
1005 {
1006         cryptomempool = Mem_AllocPool("crypto", 0, NULL);
1007
1008         if(!Crypto_OpenLibrary())
1009                 return;
1010
1011         qd0_blind_id_setmallocfuncs(Crypto_d0_malloc, Crypto_d0_free);
1012         if (Thread_HasThreads())
1013                 qd0_blind_id_setmutexfuncs(Crypto_d0_createmutex, Crypto_d0_destroymutex, Crypto_d0_lockmutex, Crypto_d0_unlockmutex);
1014
1015         if(!qd0_blind_id_INITIALIZE())
1016         {
1017                 Crypto_Rijndael_CloseLibrary();
1018                 Crypto_CloseLibrary();
1019                 Con_Printf("libd0_blind_id initialization FAILED, cryptography support has been disabled\n");
1020                 return;
1021         }
1022
1023         Crypto_Rijndael_OpenLibrary(); // if this fails, it's uncritical
1024
1025         Crypto_InitHostKeys();
1026 }
1027 // end
1028
1029 qboolean Crypto_Available(void)
1030 {
1031         if(!d0_blind_id_dll)
1032                 return false;
1033         return true;
1034 }
1035
1036 // keygen code
1037 static void Crypto_KeyGen_Finished(int code, size_t length_received, unsigned char *buffer, void *cbdata)
1038 {
1039         const char *p[1];
1040         size_t l[1];
1041         static char buf[8192];
1042         static char buf2[8192];
1043         size_t buf2size;
1044         qfile_t *f = NULL;
1045         D0_BOOL status;
1046         char vabuf[1024];
1047
1048         SV_LockThreadMutex();
1049
1050         if(!d0_blind_id_dll)
1051         {
1052                 Con_Print("libd0_blind_id DLL not found, this command is inactive.\n");
1053                 keygen_i = -1;
1054                 SV_UnlockThreadMutex();
1055                 return;
1056         }
1057
1058         if(keygen_i >= MAX_PUBKEYS || !pubkeys[keygen_i])
1059         {
1060                 Con_Printf("overflow of keygen_i\n");
1061                 keygen_i = -1;
1062                 SV_UnlockThreadMutex();
1063                 return;
1064         }
1065         if(keygen_i < 0)
1066         {
1067                 Con_Printf("Unexpected response from keygen server:\n");
1068                 Com_HexDumpToConsole(buffer, length_received);
1069                 SV_UnlockThreadMutex();
1070                 return;
1071         }
1072         if(!Crypto_ParsePack((const char *) buffer, length_received, FOURCC_D0IR, p, l, 1))
1073         {
1074                 if(length_received >= 5 && Crypto_LittleLong((const char *) buffer) == FOURCC_D0ER)
1075                 {
1076                         Con_Printf("Error response from keygen server: %.*s\n", (int)(length_received - 5), buffer + 5);
1077                 }
1078                 else
1079                 {
1080                         Con_Printf("Invalid response from keygen server:\n");
1081                         Com_HexDumpToConsole(buffer, length_received);
1082                 }
1083                 keygen_i = -1;
1084                 SV_UnlockThreadMutex();
1085                 return;
1086         }
1087         if(!qd0_blind_id_finish_private_id_request(pubkeys[keygen_i], p[0], l[0]))
1088         {
1089                 Con_Printf("d0_blind_id_finish_private_id_request failed\n");
1090                 keygen_i = -1;
1091                 SV_UnlockThreadMutex();
1092                 return;
1093         }
1094
1095         // verify the key we just got (just in case)
1096         if(!qd0_blind_id_verify_public_id(pubkeys[keygen_i], &status) || !status)
1097         {
1098                 Con_Printf("d0_blind_id_verify_public_id failed\n");
1099                 keygen_i = -1;
1100                 SV_UnlockThreadMutex();
1101                 return;
1102         }
1103
1104         // we have a valid key now!
1105         // make the rest of crypto.c know that
1106         Con_Printf("Received signature for private ID key_%d.d0pk (public key fingerprint: %s)\n", keygen_i, pubkeys_priv_fp64[keygen_i]);
1107         pubkeys_havesig[keygen_i] = true;
1108
1109         // write the key to disk
1110         p[0] = buf;
1111         l[0] = sizeof(buf);
1112         if(!qd0_blind_id_write_private_id(pubkeys[keygen_i], buf, &l[0]))
1113         {
1114                 Con_Printf("d0_blind_id_write_private_id failed\n");
1115                 keygen_i = -1;
1116                 SV_UnlockThreadMutex();
1117                 return;
1118         }
1119         if(!(buf2size = Crypto_UnParsePack(buf2, sizeof(buf2), FOURCC_D0SI, p, l, 1)))
1120         {
1121                 Con_Printf("Crypto_UnParsePack failed\n");
1122                 keygen_i = -1;
1123                 SV_UnlockThreadMutex();
1124                 return;
1125         }
1126
1127         FS_CreatePath(va(vabuf, sizeof(vabuf), "%skey_%d.d0si%s", *fs_userdir ? fs_userdir : fs_basedir, keygen_i, sessionid.string));
1128         f = FS_SysOpen(va(vabuf, sizeof(vabuf), "%skey_%d.d0si%s", *fs_userdir ? fs_userdir : fs_basedir, keygen_i, sessionid.string), "wb", false);
1129         if(!f)
1130         {
1131                 Con_Printf("Cannot open key_%d.d0si%s\n", keygen_i, sessionid.string);
1132                 keygen_i = -1;
1133                 SV_UnlockThreadMutex();
1134                 return;
1135         }
1136         FS_Write(f, buf2, buf2size);
1137         FS_Close(f);
1138
1139         Con_Printf("Saved to key_%d.d0si%s\n", keygen_i, sessionid.string);
1140         keygen_i = -1;
1141         SV_UnlockThreadMutex();
1142 }
1143
1144 static void Crypto_KeyGen_f(void)
1145 {
1146         int i;
1147         const char *p[1];
1148         size_t l[1];
1149         static char buf[8192];
1150         static char buf2[8192];
1151         size_t buf2size;
1152         size_t buf2l, buf2pos;
1153         char vabuf[1024];
1154         size_t len2;
1155         qfile_t *f = NULL;
1156
1157         if(!d0_blind_id_dll)
1158         {
1159                 Con_Print("libd0_blind_id DLL not found, this command is inactive.\n");
1160                 return;
1161         }
1162         if(Cmd_Argc() != 3)
1163         {
1164                 Con_Printf("usage:\n%s id url\n", Cmd_Argv(0));
1165                 return;
1166         }
1167         SV_LockThreadMutex();
1168         Crypto_LoadKeys();
1169         i = atoi(Cmd_Argv(1));
1170         if(!pubkeys[i])
1171         {
1172                 Con_Printf("there is no public key %d\n", i);
1173                 SV_UnlockThreadMutex();
1174                 return;
1175         }
1176         if(keygen_i >= 0)
1177         {
1178                 Con_Printf("there is already a keygen run on the way\n");
1179                 SV_UnlockThreadMutex();
1180                 return;
1181         }
1182         keygen_i = i;
1183
1184         // how to START the keygenning...
1185         if(pubkeys_havepriv[keygen_i])
1186         {
1187                 if(pubkeys_havesig[keygen_i])
1188                 {
1189                         Con_Printf("there is already a signed private key for %d\n", i);
1190                         keygen_i = -1;
1191                         SV_UnlockThreadMutex();
1192                         return;
1193                 }
1194                 // if we get here, we only need a signature, no new keygen run needed
1195                 Con_Printf("Only need a signature for an existing key...\n");
1196         }
1197         else
1198         {
1199                 // we also need a new ID itself
1200                 if(!qd0_blind_id_generate_private_id_start(pubkeys[keygen_i]))
1201                 {
1202                         Con_Printf("d0_blind_id_start failed\n");
1203                         keygen_i = -1;
1204                         SV_UnlockThreadMutex();
1205                         return;
1206                 }
1207                 // verify the key we just got (just in case)
1208                 if(!qd0_blind_id_verify_private_id(pubkeys[keygen_i]))
1209                 {
1210                         Con_Printf("d0_blind_id_verify_private_id failed\n");
1211                         keygen_i = -1;
1212                         SV_UnlockThreadMutex();
1213                         return;
1214                 }
1215                 // we have a valid key now!
1216                 // make the rest of crypto.c know that
1217                 len2 = FP64_SIZE;
1218                 if(qd0_blind_id_fingerprint64_public_id(pubkeys[keygen_i], pubkeys_priv_fp64[keygen_i], &len2)) // keeps final NUL
1219                 {
1220                         Con_Printf("Generated private ID key_%d.d0pk (public key fingerprint: %s)\n", keygen_i, pubkeys_priv_fp64[keygen_i]);
1221                         pubkeys_havepriv[keygen_i] = true;
1222                         strlcat(crypto_idstring_buf, va(vabuf, sizeof(vabuf), " %s@%s", pubkeys_priv_fp64[keygen_i], pubkeys_fp64[keygen_i]), sizeof(crypto_idstring_buf));
1223                         crypto_idstring = crypto_idstring_buf;
1224                         Crypto_BuildChallengeAppend();
1225                 }
1226                 // write the key to disk
1227                 p[0] = buf;
1228                 l[0] = sizeof(buf);
1229                 if(!qd0_blind_id_write_private_id(pubkeys[keygen_i], buf, &l[0]))
1230                 {
1231                         Con_Printf("d0_blind_id_write_private_id failed\n");
1232                         keygen_i = -1;
1233                         SV_UnlockThreadMutex();
1234                         return;
1235                 }
1236                 if(!(buf2size = Crypto_UnParsePack(buf2, sizeof(buf2), FOURCC_D0SI, p, l, 1)))
1237                 {
1238                         Con_Printf("Crypto_UnParsePack failed\n");
1239                         keygen_i = -1;
1240                         SV_UnlockThreadMutex();
1241                         return;
1242                 }
1243
1244                 FS_CreatePath(va(vabuf, sizeof(vabuf), "%skey_%d.d0si%s", *fs_userdir ? fs_userdir : fs_basedir, keygen_i, sessionid.string));
1245                 f = FS_SysOpen(va(vabuf, sizeof(vabuf), "%skey_%d.d0si%s", *fs_userdir ? fs_userdir : fs_basedir, keygen_i, sessionid.string), "wb", false);
1246                 if(!f)
1247                 {
1248                         Con_Printf("Cannot open key_%d.d0si%s\n", keygen_i, sessionid.string);
1249                         keygen_i = -1;
1250                         SV_UnlockThreadMutex();
1251                         return;
1252                 }
1253                 FS_Write(f, buf2, buf2size);
1254                 FS_Close(f);
1255
1256                 f = FS_SysOpen(va(vabuf, sizeof(vabuf), "%skey_%d-public-fp%s.txt", *fs_userdir ? fs_userdir : fs_basedir, keygen_i, sessionid.string), "w", false);
1257                 if(f)
1258                 {
1259                         // we ignore errors for this file, as it's not necessary to have
1260                         FS_Write(f, pubkeys_priv_fp64[keygen_i], FP64_SIZE);
1261                         FS_Write(f, "\n", 1);
1262                         FS_Close(f);
1263                 }
1264
1265                 Con_Printf("Saved unsigned key to key_%d.d0si%s\n", keygen_i, sessionid.string);
1266         }
1267         p[0] = buf;
1268         l[0] = sizeof(buf);
1269         if(!qd0_blind_id_generate_private_id_request(pubkeys[keygen_i], buf, &l[0]))
1270         {
1271                 Con_Printf("d0_blind_id_generate_private_id_request failed\n");
1272                 keygen_i = -1;
1273                 SV_UnlockThreadMutex();
1274                 return;
1275         }
1276         buf2pos = strlen(Cmd_Argv(2));
1277         memcpy(buf2, Cmd_Argv(2), buf2pos);
1278         if(!(buf2l = Crypto_UnParsePack(buf2 + buf2pos, sizeof(buf2) - buf2pos - 1, FOURCC_D0IQ, p, l, 1)))
1279         {
1280                 Con_Printf("Crypto_UnParsePack failed\n");
1281                 keygen_i = -1;
1282                 SV_UnlockThreadMutex();
1283                 return;
1284         }
1285         if(!(buf2l = base64_encode((unsigned char *) (buf2 + buf2pos), buf2l, sizeof(buf2) - buf2pos - 1)))
1286         {
1287                 Con_Printf("base64_encode failed\n");
1288                 keygen_i = -1;
1289                 SV_UnlockThreadMutex();
1290                 return;
1291         }
1292         buf2l += buf2pos;
1293         buf[buf2l] = 0;
1294         if(!Curl_Begin_ToMemory(buf2, 0, (unsigned char *) keygen_buf, sizeof(keygen_buf), Crypto_KeyGen_Finished, NULL))
1295         {
1296                 Con_Printf("curl failed\n");
1297                 keygen_i = -1;
1298                 SV_UnlockThreadMutex();
1299                 return;
1300         }
1301         Con_Printf("Signature generation in progress...\n");
1302         SV_UnlockThreadMutex();
1303 }
1304 // end
1305
1306 // console commands
1307 static void Crypto_Reload_f(void)
1308 {
1309         Crypto_ClearHostKeys();
1310         Crypto_UnloadKeys();
1311         Crypto_LoadKeys();
1312 }
1313
1314 static void Crypto_Keys_f(void)
1315 {
1316         int i;
1317         if(!d0_blind_id_dll)
1318         {
1319                 Con_Print("libd0_blind_id DLL not found, this command is inactive.\n");
1320                 return;
1321         }
1322         for(i = 0; i < MAX_PUBKEYS; ++i)
1323         {
1324                 if(pubkeys[i])
1325                 {
1326                         Con_Printf("%2d: public key key_%d.d0pk (fingerprint: %s)\n", i, i, pubkeys_fp64[i]);
1327                         if(pubkeys_havepriv[i])
1328                         {
1329                                 Con_Printf("    private ID key_%d.d0si%s (public key fingerprint: %s)\n", i, sessionid.string, pubkeys_priv_fp64[i]);
1330                                 if(!pubkeys_havesig[i])
1331                                         Con_Printf("    NOTE: this ID has not yet been signed!\n");
1332                         }
1333                 }
1334         }
1335 }
1336
1337 static void Crypto_HostKeys_f(void)
1338 {
1339         int i;
1340         crypto_storedhostkey_t *hk;
1341         char buf[128];
1342
1343         if(!d0_blind_id_dll)
1344         {
1345                 Con_Print("libd0_blind_id DLL not found, this command is inactive.\n");
1346                 return;
1347         }
1348         for(i = 0; i < CRYPTO_HOSTKEY_HASHSIZE; ++i)
1349         {
1350                 for(hk = crypto_storedhostkey_hashtable[i]; hk; hk = hk->next)
1351                 {
1352                         LHNETADDRESS_ToString(&hk->addr, buf, sizeof(buf), 1);
1353                         Con_Printf("%d %s@%.*s %s\n",
1354                                         hk->aeslevel,
1355                                         hk->idfp,
1356                                         crypto_keyfp_recommended_length, pubkeys_fp64[hk->keyid],
1357                                         buf);
1358                 }
1359         }
1360 }
1361
1362 static void Crypto_HostKey_Clear_f(void)
1363 {
1364         lhnetaddress_t addr;
1365         int i;
1366
1367         if(!d0_blind_id_dll)
1368         {
1369                 Con_Print("libd0_blind_id DLL not found, this command is inactive.\n");
1370                 return;
1371         }
1372
1373         for(i = 1; i < Cmd_Argc(); ++i)
1374         {
1375                 LHNETADDRESS_FromString(&addr, Cmd_Argv(i), 26000);
1376                 if(Crypto_ClearHostKey(&addr))
1377                 {
1378                         Con_Printf("cleared host key for %s\n", Cmd_Argv(i));
1379                 }
1380         }
1381 }
1382
1383 void Crypto_Init_Commands(void)
1384 {
1385         if(d0_blind_id_dll)
1386         {
1387                 Cmd_AddCommand("crypto_reload", Crypto_Reload_f, "reloads cryptographic keys");
1388                 Cmd_AddCommand("crypto_keygen", Crypto_KeyGen_f, "generates and saves a cryptographic key");
1389                 Cmd_AddCommand("crypto_keys", Crypto_Keys_f, "lists the loaded keys");
1390                 Cmd_AddCommand("crypto_hostkeys", Crypto_HostKeys_f, "lists the cached host keys");
1391                 Cmd_AddCommand("crypto_hostkey_clear", Crypto_HostKey_Clear_f, "clears a cached host key");
1392                 Cvar_RegisterVariable(&crypto_developer);
1393                 if(d0_rijndael_dll)
1394                         Cvar_RegisterVariable(&crypto_aeslevel);
1395                 else
1396                         crypto_aeslevel.integer = 0; // make sure
1397                 Cvar_RegisterVariable(&crypto_servercpupercent);
1398                 Cvar_RegisterVariable(&crypto_servercpumaxtime);
1399                 Cvar_RegisterVariable(&crypto_servercpudebug);
1400         }
1401 }
1402 // end
1403
1404 // AES encryption
1405 static void aescpy(unsigned char *key, const unsigned char *iv, unsigned char *dst, const unsigned char *src, size_t len)
1406 {
1407         const unsigned char *xorpos = iv;
1408         unsigned char xorbuf[16];
1409         unsigned long rk[D0_RIJNDAEL_RKLENGTH(DHKEY_SIZE * 8)];
1410         size_t i;
1411         qd0_rijndael_setup_encrypt(rk, key, DHKEY_SIZE * 8);
1412         while(len > 16)
1413         {
1414                 for(i = 0; i < 16; ++i)
1415                         xorbuf[i] = src[i] ^ xorpos[i];
1416                 qd0_rijndael_encrypt(rk, D0_RIJNDAEL_NROUNDS(DHKEY_SIZE * 8), xorbuf, dst);
1417                 xorpos = dst;
1418                 len -= 16;
1419                 src += 16;
1420                 dst += 16;
1421         }
1422         if(len > 0)
1423         {
1424                 for(i = 0; i < len; ++i)
1425                         xorbuf[i] = src[i] ^ xorpos[i];
1426                 for(; i < 16; ++i)
1427                         xorbuf[i] = xorpos[i];
1428                 qd0_rijndael_encrypt(rk, D0_RIJNDAEL_NROUNDS(DHKEY_SIZE * 8), xorbuf, dst);
1429         }
1430 }
1431 static void seacpy(unsigned char *key, const unsigned char *iv, unsigned char *dst, const unsigned char *src, size_t len)
1432 {
1433         const unsigned char *xorpos = iv;
1434         unsigned char xorbuf[16];
1435         unsigned long rk[D0_RIJNDAEL_RKLENGTH(DHKEY_SIZE * 8)];
1436         size_t i;
1437         qd0_rijndael_setup_decrypt(rk, key, DHKEY_SIZE * 8);
1438         while(len > 16)
1439         {
1440                 qd0_rijndael_decrypt(rk, D0_RIJNDAEL_NROUNDS(DHKEY_SIZE * 8), src, xorbuf);
1441                 for(i = 0; i < 16; ++i)
1442                         dst[i] = xorbuf[i] ^ xorpos[i];
1443                 xorpos = src;
1444                 len -= 16;
1445                 src += 16;
1446                 dst += 16;
1447         }
1448         if(len > 0)
1449         {
1450                 qd0_rijndael_decrypt(rk, D0_RIJNDAEL_NROUNDS(DHKEY_SIZE * 8), src, xorbuf);
1451                 for(i = 0; i < len; ++i)
1452                         dst[i] = xorbuf[i] ^ xorpos[i];
1453         }
1454 }
1455
1456 // NOTE: we MUST avoid the following begins of the packet:
1457 //   1. 0xFF, 0xFF, 0xFF, 0xFF
1458 //   2. 0x80, 0x00, length/256, length%256
1459 // this luckily does NOT affect AES mode, where the first byte always is in the range from 0x00 to 0x0F
1460 const void *Crypto_EncryptPacket(crypto_t *crypto, const void *data_src, size_t len_src, void *data_dst, size_t *len_dst, size_t len)
1461 {
1462         unsigned char h[32];
1463         int i;
1464         if(crypto->authenticated)
1465         {
1466                 if(crypto->use_aes)
1467                 {
1468                         // AES packet = 1 byte length overhead, 15 bytes from HMAC-SHA-256, data, 0..15 bytes padding
1469                         // 15 bytes HMAC-SHA-256 (112bit) suffice as the attacker can't do more than forge a random-looking packet
1470                         // HMAC is needed to not leak information about packet content
1471                         if(developer_networking.integer)
1472                         {
1473                                 Con_Print("To be encrypted:\n");
1474                                 Com_HexDumpToConsole((const unsigned char *) data_src, len_src);
1475                         }
1476                         if(len_src + 32 > len || !HMAC_SHA256_32BYTES(h, (const unsigned char *) data_src, len_src, crypto->dhkey, DHKEY_SIZE))
1477                         {
1478                                 Con_Printf("Crypto_EncryptPacket failed (not enough space: %d bytes in, %d bytes out)\n", (int) len_src, (int) len);
1479                                 return NULL;
1480                         }
1481                         *len_dst = ((len_src + 15) / 16) * 16 + 16; // add 16 for HMAC, then round to 16-size for AES
1482                         ((unsigned char *) data_dst)[0] = *len_dst - len_src;
1483                         memcpy(((unsigned char *) data_dst)+1, h, 15);
1484                         aescpy(crypto->dhkey, (const unsigned char *) data_dst, ((unsigned char *) data_dst) + 16, (const unsigned char *) data_src, len_src);
1485                         //                    IV                                dst                                src                               len
1486                 }
1487                 else
1488                 {
1489                         // HMAC packet = 16 bytes HMAC-SHA-256 (truncated to 128 bits), data
1490                         if(len_src + 16 > len || !HMAC_SHA256_32BYTES(h, (const unsigned char *) data_src, len_src, crypto->dhkey, DHKEY_SIZE))
1491                         {
1492                                 Con_Printf("Crypto_EncryptPacket failed (not enough space: %d bytes in, %d bytes out)\n", (int) len_src, (int) len);
1493                                 return NULL;
1494                         }
1495                         *len_dst = len_src + 16;
1496                         memcpy(data_dst, h, 16);
1497                         memcpy(((unsigned char *) data_dst) + 16, (unsigned char *) data_src, len_src);
1498
1499                         // handle the "avoid" conditions:
1500                         i = BuffBigLong((unsigned char *) data_dst);
1501                         if(
1502                                 (i == (int)0xFFFFFFFF) // avoid QW control packet
1503                                 ||
1504                                 (i == (int)0x80000000 + (int)*len_dst) // avoid NQ control packet
1505                         )
1506                                 *(unsigned char *)data_dst ^= 0x80; // this will ALWAYS fix it
1507                 }
1508                 return data_dst;
1509         }
1510         else
1511         {
1512                 *len_dst = len_src;
1513                 return data_src;
1514         }
1515 }
1516
1517 const void *Crypto_DecryptPacket(crypto_t *crypto, const void *data_src, size_t len_src, void *data_dst, size_t *len_dst, size_t len)
1518 {
1519         unsigned char h[32];
1520         int i;
1521
1522         // silently handle non-crypto packets
1523         i = BuffBigLong((unsigned char *) data_src);
1524         if(
1525                 (i == (int)0xFFFFFFFF) // avoid QW control packet
1526                 ||
1527                 (i == (int)0x80000000 + (int)len_src) // avoid NQ control packet
1528         )
1529                 return NULL;
1530
1531         if(crypto->authenticated)
1532         {
1533                 if(crypto->use_aes)
1534                 {
1535                         if(len_src < 16 || ((len_src - 16) % 16))
1536                         {
1537                                 Con_Printf("Crypto_DecryptPacket failed (not enough space: %d bytes in, %d bytes out)\n", (int) len_src, (int) len);
1538                                 return NULL;
1539                         }
1540                         *len_dst = len_src - ((unsigned char *) data_src)[0];
1541                         if(len < *len_dst || *len_dst > len_src - 16)
1542                         {
1543                                 Con_Printf("Crypto_DecryptPacket failed (not enough space: %d bytes in, %d->%d bytes out)\n", (int) len_src, (int) *len_dst, (int) len);
1544                                 return NULL;
1545                         }
1546                         seacpy(crypto->dhkey, (unsigned char *) data_src, (unsigned char *) data_dst, ((const unsigned char *) data_src) + 16, *len_dst);
1547                         //                    IV                          dst                         src                                      len
1548                         if(!HMAC_SHA256_32BYTES(h, (const unsigned char *) data_dst, *len_dst, crypto->dhkey, DHKEY_SIZE))
1549                         {
1550                                 Con_Printf("HMAC fail\n");
1551                                 return NULL;
1552                         }
1553                         if(memcmp(((const unsigned char *) data_src)+1, h, 15)) // ignore first byte, used for length
1554                         {
1555                                 Con_Printf("HMAC mismatch\n");
1556                                 return NULL;
1557                         }
1558                         if(developer_networking.integer)
1559                         {
1560                                 Con_Print("Decrypted:\n");
1561                                 Com_HexDumpToConsole((const unsigned char *) data_dst, *len_dst);
1562                         }
1563                         return data_dst; // no need to copy
1564                 }
1565                 else
1566                 {
1567                         if(len_src < 16)
1568                         {
1569                                 Con_Printf("Crypto_DecryptPacket failed (not enough space: %d bytes in, %d bytes out)\n", (int) len_src, (int) len);
1570                                 return NULL;
1571                         }
1572                         *len_dst = len_src - 16;
1573                         if(len < *len_dst)
1574                         {
1575                                 Con_Printf("Crypto_DecryptPacket failed (not enough space: %d bytes in, %d->%d bytes out)\n", (int) len_src, (int) *len_dst, (int) len);
1576                                 return NULL;
1577                         }
1578                         //memcpy(data_dst, data_src + 16, *len_dst);
1579                         if(!HMAC_SHA256_32BYTES(h, ((const unsigned char *) data_src) + 16, *len_dst, crypto->dhkey, DHKEY_SIZE))
1580                         {
1581                                 Con_Printf("HMAC fail\n");
1582                                 Com_HexDumpToConsole((const unsigned char *) data_src, len_src);
1583                                 return NULL;
1584                         }
1585
1586                         if(memcmp((const unsigned char *) data_src, h, 16)) // ignore first byte, used for length
1587                         {
1588                                 // undo the "avoid conditions"
1589                                 if(
1590                                                 (i == (int)0x7FFFFFFF) // avoided QW control packet
1591                                                 ||
1592                                                 (i == (int)0x00000000 + (int)len_src) // avoided NQ control packet
1593                                   )
1594                                 {
1595                                         // do the avoidance on the hash too
1596                                         h[0] ^= 0x80;
1597                                         if(memcmp((const unsigned char *) data_src, h, 16)) // ignore first byte, used for length
1598                                         {
1599                                                 Con_Printf("HMAC mismatch\n");
1600                                                 Com_HexDumpToConsole((const unsigned char *) data_src, len_src);
1601                                                 return NULL;
1602                                         }
1603                                 }
1604                                 else
1605                                 {
1606                                         Con_Printf("HMAC mismatch\n");
1607                                         Com_HexDumpToConsole((const unsigned char *) data_src, len_src);
1608                                         return NULL;
1609                                 }
1610                         }
1611                         return ((const unsigned char *) data_src) + 16; // no need to copy, so data_dst is not used
1612                 }
1613         }
1614         else
1615         {
1616                 *len_dst = len_src;
1617                 return data_src;
1618         }
1619 }
1620 // end
1621
1622 const char *Crypto_GetInfoResponseDataString(void)
1623 {
1624         crypto_idstring_buf[0] = '0' + crypto_aeslevel.integer;
1625         return crypto_idstring;
1626 }
1627
1628 // network protocol
1629 qboolean Crypto_ServerAppendToChallenge(const char *data_in, size_t len_in, char *data_out, size_t *len_out, size_t maxlen_out)
1630 {
1631         // cheap op, all is precomputed
1632         if(!d0_blind_id_dll)
1633                 return false; // no support
1634         // append challenge
1635         if(maxlen_out <= *len_out + challenge_append_length)
1636                 return false;
1637         memcpy(data_out + *len_out, challenge_append, challenge_append_length);
1638         *len_out += challenge_append_length;
1639         return false;
1640 }
1641
1642 static int Crypto_ServerError(char *data_out, size_t *len_out, const char *msg, const char *msg_client)
1643 {
1644         if(!msg_client)
1645                 msg_client = msg;
1646         Con_DPrintf("rejecting client: %s\n", msg);
1647         if(*msg_client)
1648                 dpsnprintf(data_out, *len_out, "reject %s", msg_client);
1649         *len_out = strlen(data_out);
1650         return CRYPTO_DISCARD;
1651 }
1652
1653 static int Crypto_SoftServerError(char *data_out, size_t *len_out, const char *msg)
1654 {
1655         *len_out = 0;
1656         Con_DPrintf("%s\n", msg);
1657         return CRYPTO_DISCARD;
1658 }
1659
1660 static int Crypto_ServerParsePacket_Internal(const char *data_in, size_t len_in, char *data_out, size_t *len_out, lhnetaddress_t *peeraddress)
1661 {
1662         // if "connect": reject if in the middle of crypto handshake
1663         crypto_t *crypto = NULL;
1664         char *data_out_p = data_out;
1665         const char *string = data_in;
1666         int aeslevel;
1667         D0_BOOL aes;
1668         D0_BOOL status;
1669         char infostringvalue[MAX_INPUTLINE];
1670         char vabuf[1024];
1671
1672         if(!d0_blind_id_dll)
1673                 return CRYPTO_NOMATCH; // no support
1674
1675         if (len_in > 8 && !memcmp(string, "connect\\", 8) && d0_rijndael_dll && crypto_aeslevel.integer >= 3)
1676         {
1677                 const char *s;
1678                 int i;
1679                 // sorry, we have to verify the challenge here to not reflect network spam
1680
1681                 if (!(s = InfoString_GetValue(string + 4, "challenge", infostringvalue, sizeof(infostringvalue))))
1682                         return CRYPTO_NOMATCH; // will be later accepted if encryption was set up
1683                 // validate the challenge
1684                 for (i = 0;i < MAX_CHALLENGES;i++)
1685                         if(challenge[i].time > 0)
1686                                 if (!LHNETADDRESS_Compare(peeraddress, &challenge[i].address) && !strcmp(challenge[i].string, s))
1687                                         break;
1688                 // if the challenge is not recognized, drop the packet
1689                 if (i == MAX_CHALLENGES) // challenge mismatch is silent
1690                         return CRYPTO_DISCARD; // pre-challenge: rather be silent
1691
1692                 crypto = Crypto_ServerFindInstance(peeraddress, false);
1693                 if(!crypto || !crypto->authenticated)
1694                         return Crypto_ServerError(data_out, len_out, "This server requires authentication and encryption to be supported by your client", NULL);
1695         }
1696         else if(len_in > 5 && !memcmp(string, "d0pk\\", 5) && ((LHNETADDRESS_GetAddressType(peeraddress) == LHNETADDRESSTYPE_LOOP) || sv_public.integer > -3))
1697         {
1698                 const char *cnt, *s, *p;
1699                 int id;
1700                 int clientid = -1, serverid = -1;
1701                 cnt = InfoString_GetValue(string + 4, "id", infostringvalue, sizeof(infostringvalue));
1702                 id = (cnt ? atoi(cnt) : -1);
1703                 cnt = InfoString_GetValue(string + 4, "cnt", infostringvalue, sizeof(infostringvalue));
1704                 if(!cnt)
1705                         return CRYPTO_DISCARD; // pre-challenge: rather be silent
1706                 GetUntilNul(&data_in, &len_in);
1707                 if(!data_in)
1708                         return CRYPTO_DISCARD; // pre-challenge: rather be silent
1709                 if(!strcmp(cnt, "0"))
1710                 {
1711                         int i;
1712                         if (!(s = InfoString_GetValue(string + 4, "challenge", infostringvalue, sizeof(infostringvalue))))
1713                                 return CRYPTO_DISCARD; // pre-challenge: rather be silent
1714                         // validate the challenge
1715                         for (i = 0;i < MAX_CHALLENGES;i++)
1716                                 if(challenge[i].time > 0)
1717                                         if (!LHNETADDRESS_Compare(peeraddress, &challenge[i].address) && !strcmp(challenge[i].string, s))
1718                                                 break;
1719                         // if the challenge is not recognized, drop the packet
1720                         if (i == MAX_CHALLENGES) // challenge mismatch is silent
1721                                 return CRYPTO_DISCARD; // pre-challenge: rather be silent
1722
1723                         if (!(s = InfoString_GetValue(string + 4, "aeslevel", infostringvalue, sizeof(infostringvalue))))
1724                                 aeslevel = 0; // not supported
1725                         else
1726                                 aeslevel = bound(0, atoi(s), 3);
1727                         switch(bound(0, d0_rijndael_dll ? crypto_aeslevel.integer : 0, 3))
1728                         {
1729                                 default: // dummy, never happens, but to make gcc happy...
1730                                 case 0:
1731                                         if(aeslevel >= 3)
1732                                                 return Crypto_ServerError(data_out, len_out, "This server requires encryption to be not required (crypto_aeslevel <= 2)", NULL);
1733                                         aes = false;
1734                                         break;
1735                                 case 1:
1736                                         aes = (aeslevel >= 2);
1737                                         break;
1738                                 case 2:
1739                                         aes = (aeslevel >= 1);
1740                                         break;
1741                                 case 3:
1742                                         if(aeslevel <= 0)
1743                                                 return Crypto_ServerError(data_out, len_out, "This server requires encryption to be supported (crypto_aeslevel >= 1, and d0_rijndael library must be present)", NULL);
1744                                         aes = true;
1745                                         break;
1746                         }
1747
1748                         p = GetUntilNul(&data_in, &len_in);
1749                         if(p && *p)
1750                         {
1751                                 for(i = 0; i < MAX_PUBKEYS; ++i)
1752                                 {
1753                                         if(pubkeys[i])
1754                                                 if(!strcmp(p, pubkeys_fp64[i]))
1755                                                         if(pubkeys_havepriv[i])
1756                                                                 if(serverid < 0)
1757                                                                         serverid = i;
1758                                 }
1759                                 if(serverid < 0)
1760                                         return Crypto_ServerError(data_out, len_out, "Invalid server key", NULL);
1761                         }
1762                         p = GetUntilNul(&data_in, &len_in);
1763                         if(p && *p)
1764                         {
1765                                 for(i = 0; i < MAX_PUBKEYS; ++i)
1766                                 {
1767                                         if(pubkeys[i])
1768                                                 if(!strcmp(p, pubkeys_fp64[i]))
1769                                                         if(clientid < 0)
1770                                                                 clientid = i;
1771                                 }
1772                                 if(clientid < 0)
1773                                         return Crypto_ServerError(data_out, len_out, "Invalid client key", NULL);
1774                         }
1775
1776                         crypto = Crypto_ServerFindInstance(peeraddress, true);
1777                         if(!crypto)
1778                                 return Crypto_ServerError(data_out, len_out, "Could not create a crypto connect instance", NULL);
1779                         MAKE_CDATA;
1780                         CDATA->cdata_id = id;
1781                         CDATA->s = serverid;
1782                         CDATA->c = clientid;
1783                         memset(crypto->dhkey, 0, sizeof(crypto->dhkey));
1784                         CDATA->challenge[0] = 0;
1785                         crypto->client_keyfp[0] = 0;
1786                         crypto->client_idfp[0] = 0;
1787                         crypto->server_keyfp[0] = 0;
1788                         crypto->server_idfp[0] = 0;
1789                         crypto->use_aes = aes != 0;
1790
1791                         if(CDATA->s >= 0)
1792                         {
1793                                 // I am the server, and my key is ok... so let's set server_keyfp and server_idfp
1794                                 strlcpy(crypto->server_keyfp, pubkeys_fp64[CDATA->s], sizeof(crypto->server_keyfp));
1795                                 strlcpy(crypto->server_idfp, pubkeys_priv_fp64[CDATA->s], sizeof(crypto->server_idfp));
1796
1797                                 if(!CDATA->id)
1798                                         CDATA->id = qd0_blind_id_new();
1799                                 if(!CDATA->id)
1800                                 {
1801                                         CLEAR_CDATA;
1802                                         return Crypto_ServerError(data_out, len_out, "d0_blind_id_new failed", "Internal error");
1803                                 }
1804                                 if(!qd0_blind_id_copy(CDATA->id, pubkeys[CDATA->s]))
1805                                 {
1806                                         CLEAR_CDATA;
1807                                         return Crypto_ServerError(data_out, len_out, "d0_blind_id_copy failed", "Internal error");
1808                                 }
1809                                 PutWithNul(&data_out_p, len_out, va(vabuf, sizeof(vabuf), "d0pk\\cnt\\1\\id\\%d\\aes\\%d", CDATA->cdata_id, crypto->use_aes));
1810                                 if(!qd0_blind_id_authenticate_with_private_id_start(CDATA->id, true, false, "XONOTIC", 8, data_out_p, len_out)) // len_out receives used size by this op
1811                                 {
1812                                         CLEAR_CDATA;
1813                                         return Crypto_ServerError(data_out, len_out, "d0_blind_id_authenticate_with_private_id_start failed", "Internal error");
1814                                 }
1815                                 CDATA->next_step = 2;
1816                                 data_out_p += *len_out;
1817                                 *len_out = data_out_p - data_out;
1818                                 return CRYPTO_DISCARD;
1819                         }
1820                         else if(CDATA->c >= 0)
1821                         {
1822                                 if(!CDATA->id)
1823                                         CDATA->id = qd0_blind_id_new();
1824                                 if(!CDATA->id)
1825                                 {
1826                                         CLEAR_CDATA;
1827                                         return Crypto_ServerError(data_out, len_out, "d0_blind_id_new failed", "Internal error");
1828                                 }
1829                                 if(!qd0_blind_id_copy(CDATA->id, pubkeys[CDATA->c]))
1830                                 {
1831                                         CLEAR_CDATA;
1832                                         return Crypto_ServerError(data_out, len_out, "d0_blind_id_copy failed", "Internal error");
1833                                 }
1834                                 PutWithNul(&data_out_p, len_out, va(vabuf, sizeof(vabuf), "d0pk\\cnt\\5\\id\\%d\\aes\\%d", CDATA->cdata_id, crypto->use_aes));
1835                                 if(!qd0_blind_id_authenticate_with_private_id_challenge(CDATA->id, true, false, data_in, len_in, data_out_p, len_out, &status))
1836                                 {
1837                                         CLEAR_CDATA;
1838                                         return Crypto_ServerError(data_out, len_out, "d0_blind_id_authenticate_with_private_id_challenge failed", "Internal error");
1839                                 }
1840                                 CDATA->next_step = 6;
1841                                 data_out_p += *len_out;
1842                                 *len_out = data_out_p - data_out;
1843                                 return CRYPTO_DISCARD;
1844                         }
1845                         else
1846                         {
1847                                 CLEAR_CDATA;
1848                                 return Crypto_ServerError(data_out, len_out, "Missing client and server key", NULL);
1849                         }
1850                 }
1851                 else if(!strcmp(cnt, "2"))
1852                 {
1853                         size_t fpbuflen;
1854                         crypto = Crypto_ServerFindInstance(peeraddress, false);
1855                         if(!crypto)
1856                                 return CRYPTO_NOMATCH; // pre-challenge, rather be silent
1857                         if(id >= 0)
1858                                 if(CDATA->cdata_id != id)
1859                                         return Crypto_SoftServerError(data_out, len_out, va(vabuf, sizeof(vabuf), "Got d0pk\\id\\%d when expecting %d", id, CDATA->cdata_id));
1860                         if(CDATA->next_step != 2)
1861                                 return Crypto_SoftServerError(data_out, len_out, va(vabuf, sizeof(vabuf), "Got d0pk\\cnt\\%s when expecting %d", cnt, CDATA->next_step));
1862
1863                         PutWithNul(&data_out_p, len_out, va(vabuf, sizeof(vabuf), "d0pk\\cnt\\3\\id\\%d", CDATA->cdata_id));
1864                         if(!qd0_blind_id_authenticate_with_private_id_response(CDATA->id, data_in, len_in, data_out_p, len_out))
1865                         {
1866                                 CLEAR_CDATA;
1867                                 return Crypto_ServerError(data_out, len_out, "d0_blind_id_authenticate_with_private_id_response failed", "Internal error");
1868                         }
1869                         fpbuflen = DHKEY_SIZE;
1870                         if(!qd0_blind_id_sessionkey_public_id(CDATA->id, (char *) crypto->dhkey, &fpbuflen))
1871                         {
1872                                 CLEAR_CDATA;
1873                                 return Crypto_ServerError(data_out, len_out, "d0_blind_id_sessionkey_public_id failed", "Internal error");
1874                         }
1875                         if(CDATA->c >= 0)
1876                         {
1877                                 if(!qd0_blind_id_copy(CDATA->id, pubkeys[CDATA->c]))
1878                                 {
1879                                         CLEAR_CDATA;
1880                                         return Crypto_ServerError(data_out, len_out, "d0_blind_id_copy failed", "Internal error");
1881                                 }
1882                                 CDATA->next_step = 4;
1883                         }
1884                         else
1885                         {
1886                                 // session key is FINISHED (no server part is to be expected)! By this, all keys are set up
1887                                 crypto->authenticated = true;
1888                                 CDATA->next_step = 0;
1889                         }
1890                         data_out_p += *len_out;
1891                         *len_out = data_out_p - data_out;
1892                         return CRYPTO_DISCARD;
1893                 }
1894                 else if(!strcmp(cnt, "4"))
1895                 {
1896                         crypto = Crypto_ServerFindInstance(peeraddress, false);
1897                         if(!crypto)
1898                                 return CRYPTO_NOMATCH; // pre-challenge, rather be silent
1899                         if(id >= 0)
1900                                 if(CDATA->cdata_id != id)
1901                                         return Crypto_SoftServerError(data_out, len_out, va(vabuf, sizeof(vabuf), "Got d0pk\\id\\%d when expecting %d", id, CDATA->cdata_id));
1902                         if(CDATA->next_step != 4)
1903                                 return Crypto_SoftServerError(data_out, len_out, va(vabuf, sizeof(vabuf), "Got d0pk\\cnt\\%s when expecting %d", cnt, CDATA->next_step));
1904                         PutWithNul(&data_out_p, len_out, va(vabuf, sizeof(vabuf), "d0pk\\cnt\\5\\id\\%d", CDATA->cdata_id));
1905                         if(!qd0_blind_id_authenticate_with_private_id_challenge(CDATA->id, true, false, data_in, len_in, data_out_p, len_out, &status))
1906                         {
1907                                 CLEAR_CDATA;
1908                                 return Crypto_ServerError(data_out, len_out, "d0_blind_id_authenticate_with_private_id_challenge failed", "Internal error");
1909                         }
1910                         CDATA->next_step = 6;
1911                         data_out_p += *len_out;
1912                         *len_out = data_out_p - data_out;
1913                         return CRYPTO_DISCARD;
1914                 }
1915                 else if(!strcmp(cnt, "6"))
1916                 {
1917                         static char msgbuf[32];
1918                         size_t msgbuflen = sizeof(msgbuf);
1919                         size_t fpbuflen;
1920                         int i;
1921                         unsigned char dhkey[DHKEY_SIZE];
1922                         crypto = Crypto_ServerFindInstance(peeraddress, false);
1923                         if(!crypto)
1924                                 return CRYPTO_NOMATCH; // pre-challenge, rather be silent
1925                         if(id >= 0)
1926                                 if(CDATA->cdata_id != id)
1927                                         return Crypto_SoftServerError(data_out, len_out, va(vabuf, sizeof(vabuf), "Got d0pk\\id\\%d when expecting %d", id, CDATA->cdata_id));
1928                         if(CDATA->next_step != 6)
1929                                 return Crypto_SoftServerError(data_out, len_out, va(vabuf, sizeof(vabuf), "Got d0pk\\cnt\\%s when expecting %d", cnt, CDATA->next_step));
1930
1931                         if(!qd0_blind_id_authenticate_with_private_id_verify(CDATA->id, data_in, len_in, msgbuf, &msgbuflen, &status))
1932                         {
1933                                 CLEAR_CDATA;
1934                                 return Crypto_ServerError(data_out, len_out, "d0_blind_id_authenticate_with_private_id_verify failed (authentication error)", "Authentication error");
1935                         }
1936                         if(status)
1937                                 strlcpy(crypto->client_keyfp, pubkeys_fp64[CDATA->c], sizeof(crypto->client_keyfp));
1938                         else
1939                                 crypto->client_keyfp[0] = 0;
1940                         memset(crypto->client_idfp, 0, sizeof(crypto->client_idfp));
1941                         fpbuflen = FP64_SIZE;
1942                         if(!qd0_blind_id_fingerprint64_public_id(CDATA->id, crypto->client_idfp, &fpbuflen))
1943                         {
1944                                 CLEAR_CDATA;
1945                                 return Crypto_ServerError(data_out, len_out, "d0_blind_id_fingerprint64_public_id failed", "Internal error");
1946                         }
1947                         fpbuflen = DHKEY_SIZE;
1948                         if(!qd0_blind_id_sessionkey_public_id(CDATA->id, (char *) dhkey, &fpbuflen))
1949                         {
1950                                 CLEAR_CDATA;
1951                                 return Crypto_ServerError(data_out, len_out, "d0_blind_id_sessionkey_public_id failed", "Internal error");
1952                         }
1953                         // XOR the two DH keys together to make one
1954                         for(i = 0; i < DHKEY_SIZE; ++i)
1955                                 crypto->dhkey[i] ^= dhkey[i];
1956
1957                         // session key is FINISHED (no server part is to be expected)! By this, all keys are set up
1958                         crypto->authenticated = true;
1959                         CDATA->next_step = 0;
1960                         // send a challenge-less challenge
1961                         PutWithNul(&data_out_p, len_out, "challenge ");
1962                         *len_out = data_out_p - data_out;
1963                         --*len_out; // remove NUL terminator
1964                         return CRYPTO_MATCH;
1965                 }
1966                 return CRYPTO_NOMATCH; // pre-challenge, rather be silent
1967         }
1968         return CRYPTO_NOMATCH;
1969 }
1970
1971 int Crypto_ServerParsePacket(const char *data_in, size_t len_in, char *data_out, size_t *len_out, lhnetaddress_t *peeraddress)
1972 {
1973         int ret;
1974         double t = 0;
1975         static double complain_time = 0;
1976         const char *cnt;
1977         qboolean do_time = false;
1978         qboolean do_reject = false;
1979         char infostringvalue[MAX_INPUTLINE];
1980         if(crypto_servercpupercent.value > 0 || crypto_servercpumaxtime.value > 0)
1981                 if(len_in > 5 && !memcmp(data_in, "d0pk\\", 5))
1982                 {
1983                         do_time = true;
1984                         cnt = InfoString_GetValue(data_in + 4, "cnt", infostringvalue, sizeof(infostringvalue));
1985                         if(cnt)
1986                                 if(!strcmp(cnt, "0"))
1987                                         do_reject = true;
1988                 }
1989         if(do_time)
1990         {
1991                 // check if we may perform crypto...
1992                 if(crypto_servercpupercent.value > 0)
1993                 {
1994                         crypto_servercpu_accumulator += (realtime - crypto_servercpu_lastrealtime) * crypto_servercpupercent.value * 0.01;
1995                         if(crypto_servercpumaxtime.value)
1996                                 if(crypto_servercpu_accumulator > crypto_servercpumaxtime.value)
1997                                         crypto_servercpu_accumulator = crypto_servercpumaxtime.value;
1998                 }
1999                 else
2000                 {
2001                         if(crypto_servercpumaxtime.value > 0)
2002                                 if(realtime != crypto_servercpu_lastrealtime)
2003                                         crypto_servercpu_accumulator = crypto_servercpumaxtime.value;
2004                 }
2005                 crypto_servercpu_lastrealtime = realtime;
2006                 if(do_reject && crypto_servercpu_accumulator < 0)
2007                 {
2008                         if(realtime > complain_time + 5)
2009                                 Con_Printf("crypto: cannot perform requested crypto operations; denial service attack or crypto_servercpupercent/crypto_servercpumaxtime are too low\n");
2010                         *len_out = 0;
2011                         return CRYPTO_DISCARD;
2012                 }
2013                 t = Sys_DirtyTime();
2014         }
2015         ret = Crypto_ServerParsePacket_Internal(data_in, len_in, data_out, len_out, peeraddress);
2016         if(do_time)
2017         {
2018                 t = Sys_DirtyTime() - t;if (t < 0.0) t = 0.0; // dirtytime can step backwards
2019                 if(crypto_servercpudebug.integer)
2020                         Con_Printf("crypto: accumulator was %.1f ms, used %.1f ms for crypto, ", crypto_servercpu_accumulator * 1000, t * 1000);
2021                 crypto_servercpu_accumulator -= t;
2022                 if(crypto_servercpudebug.integer)
2023                         Con_Printf("is %.1f ms\n", crypto_servercpu_accumulator * 1000);
2024         }
2025         return ret;
2026 }
2027
2028 static int Crypto_ClientError(char *data_out, size_t *len_out, const char *msg)
2029 {
2030         dpsnprintf(data_out, *len_out, "reject %s", msg);
2031         *len_out = strlen(data_out);
2032         return CRYPTO_REPLACE;
2033 }
2034
2035 static int Crypto_SoftClientError(char *data_out, size_t *len_out, const char *msg)
2036 {
2037         *len_out = 0;
2038         Con_Printf("%s\n", msg);
2039         return CRYPTO_DISCARD;
2040 }
2041
2042 int Crypto_ClientParsePacket(const char *data_in, size_t len_in, char *data_out, size_t *len_out, lhnetaddress_t *peeraddress)
2043 {
2044         crypto_t *crypto = &cls.crypto;
2045         const char *string = data_in;
2046         const char *s;
2047         D0_BOOL aes;
2048         char *data_out_p = data_out;
2049         D0_BOOL status;
2050         char infostringvalue[MAX_INPUTLINE];
2051         char vabuf[1024];
2052
2053         if(!d0_blind_id_dll)
2054                 return CRYPTO_NOMATCH; // no support
2055
2056         // if "challenge": verify challenge, and discard message, send next crypto protocol message instead
2057         // otherwise, just handle actual protocol messages
2058
2059         if (len_in == 6 && !memcmp(string, "accept", 6) && cls.connect_trying && d0_rijndael_dll)
2060         {
2061                 int wantserverid = -1;
2062                 Crypto_RetrieveHostKey(&cls.connect_address, &wantserverid, NULL, 0, NULL, 0, NULL);
2063                 if(!crypto || !crypto->authenticated) // we ALSO get here if we are using an encrypted connection, so let's rule this out
2064                 {
2065                         if(wantserverid >= 0)
2066                                 return Crypto_ClientError(data_out, len_out, "Server tried an unauthenticated connection even though a host key is present");
2067                         if(crypto_aeslevel.integer >= 3)
2068                                 return Crypto_ClientError(data_out, len_out, "This server requires encryption to be not required (crypto_aeslevel <= 2)");
2069                 }
2070                 return CRYPTO_NOMATCH;
2071         }
2072         else if (len_in >= 1 && string[0] == 'j' && cls.connect_trying && d0_rijndael_dll)
2073         {
2074                 int wantserverid = -1;
2075                 Crypto_RetrieveHostKey(&cls.connect_address, &wantserverid, NULL, 0, NULL, 0, NULL);
2076                 //if(!crypto || !crypto->authenticated)
2077                 {
2078                         if(wantserverid >= 0)
2079                                 return Crypto_ClientError(data_out, len_out, "Server tried an unauthenticated connection even though a host key is present");
2080                         if(crypto_aeslevel.integer >= 3)
2081                                 return Crypto_ClientError(data_out, len_out, "This server requires encryption to be not required (crypto_aeslevel <= 2)");
2082                 }
2083                 return CRYPTO_NOMATCH;
2084         }
2085         else if (len_in >= 5 && BuffLittleLong((unsigned char *) string) == ((int)NETFLAG_CTL | (int)len_in))
2086         {
2087                 int wantserverid = -1;
2088
2089                 // these three are harmless
2090                 if(string[4] == CCREP_SERVER_INFO)
2091                         return CRYPTO_NOMATCH;
2092                 if(string[4] == CCREP_PLAYER_INFO)
2093                         return CRYPTO_NOMATCH;
2094                 if(string[4] == CCREP_RULE_INFO)
2095                         return CRYPTO_NOMATCH;
2096
2097                 Crypto_RetrieveHostKey(&cls.connect_address, &wantserverid, NULL, 0, NULL, 0, NULL);
2098                 //if(!crypto || !crypto->authenticated)
2099                 {
2100                         if(wantserverid >= 0)
2101                                 return Crypto_ClientError(data_out, len_out, "Server tried an unauthenticated connection even though a host key is present");
2102                         if(crypto_aeslevel.integer >= 3)
2103                                 return Crypto_ClientError(data_out, len_out, "This server requires encryption to be not required (crypto_aeslevel <= 2)");
2104                 }
2105                 return CRYPTO_NOMATCH;
2106         }
2107         else if (len_in >= 13 && !memcmp(string, "infoResponse\x0A", 13))
2108         {
2109                 s = InfoString_GetValue(string + 13, "d0_blind_id", infostringvalue, sizeof(infostringvalue));
2110                 if(s)
2111                         Crypto_StoreHostKey(peeraddress, s, true);
2112                 return CRYPTO_NOMATCH;
2113         }
2114         else if (len_in >= 15 && !memcmp(string, "statusResponse\x0A", 15))
2115         {
2116                 char save = 0;
2117                 const char *p;
2118                 p = strchr(string + 15, '\n');
2119                 if(p)
2120                 {
2121                         save = *p;
2122                         * (char *) p = 0; // cut off the string there
2123                 }
2124                 s = InfoString_GetValue(string + 15, "d0_blind_id", infostringvalue, sizeof(infostringvalue));
2125                 if(s)
2126                         Crypto_StoreHostKey(peeraddress, s, true);
2127                 if(p)
2128                 {
2129                         * (char *) p = save;
2130                         // invoking those nasal demons again (do not run this on the DS9k)
2131                 }
2132                 return CRYPTO_NOMATCH;
2133         }
2134         else if(len_in > 10 && !memcmp(string, "challenge ", 10) && cls.connect_trying)
2135         {
2136                 const char *vlen_blind_id_ptr = NULL;
2137                 size_t len_blind_id_ptr = 0;
2138                 unsigned long k, v;
2139                 const char *challenge = data_in + 10;
2140                 const char *p;
2141                 int i;
2142                 int clientid = -1, serverid = -1, wantserverid = -1;
2143                 qboolean server_can_auth = true;
2144                 char wantserver_idfp[FP64_SIZE+1];
2145                 int wantserver_aeslevel;
2146
2147                 // if we have a stored host key for the server, assume serverid to already be selected!
2148                 // (the loop will refuse to overwrite this one then)
2149                 wantserver_idfp[0] = 0;
2150                 Crypto_RetrieveHostKey(&cls.connect_address, &wantserverid, NULL, 0, wantserver_idfp, sizeof(wantserver_idfp), &wantserver_aeslevel);
2151                 // requirement: wantserver_idfp is a full ID if wantserverid set
2152
2153                 // if we leave, we have to consider the connection
2154                 // unauthenticated; NOTE: this may be faked by a clever
2155                 // attacker to force an unauthenticated connection; so we have
2156                 // a safeguard check in place when encryption is required too
2157                 // in place, or when authentication is required by the server
2158                 crypto->authenticated = false;
2159
2160                 GetUntilNul(&data_in, &len_in);
2161                 if(!data_in)
2162                         return (wantserverid >= 0) ? Crypto_ClientError(data_out, len_out, "Server tried an unauthenticated connection even though a host key is present") :
2163                                 (d0_rijndael_dll && crypto_aeslevel.integer >= 3) ? Crypto_ServerError(data_out, len_out, "This server requires encryption to be not required (crypto_aeslevel <= 2)", NULL) :
2164                                 CRYPTO_NOMATCH;
2165
2166                 // FTEQW extension protocol
2167                 while(len_in >= 8)
2168                 {
2169                         k = Crypto_LittleLong(data_in);
2170                         v = Crypto_LittleLong(data_in + 4);
2171                         data_in += 8;
2172                         len_in -= 8;
2173                         switch(k)
2174                         {
2175                                 case PROTOCOL_VLEN:
2176                                         if(len_in >= 4 + v)
2177                                         {
2178                                                 k = Crypto_LittleLong(data_in);
2179                                                 data_in += 4;
2180                                                 len_in -= 4;
2181                                                 switch(k)
2182                                                 {
2183                                                         case PROTOCOL_D0_BLIND_ID:
2184                                                                 vlen_blind_id_ptr = data_in;
2185                                                                 len_blind_id_ptr = v;
2186                                                                 break;
2187                                                 }
2188                                                 data_in += v;
2189                                                 len_in -= v;
2190                                         }
2191                                         break;
2192                                 default:
2193                                         break;
2194                         }
2195                 }
2196
2197                 if(!vlen_blind_id_ptr)
2198                         return (wantserverid >= 0) ? Crypto_ClientError(data_out, len_out, "Server tried an unauthenticated connection even though authentication is required") :
2199                                 (d0_rijndael_dll && crypto_aeslevel.integer >= 3) ? Crypto_ServerError(data_out, len_out, "This server requires encryption to be not required (crypto_aeslevel <= 2)", NULL) :
2200                                 CRYPTO_NOMATCH;
2201
2202                 data_in = vlen_blind_id_ptr;
2203                 len_in = len_blind_id_ptr;
2204
2205                 // parse fingerprints
2206                 //   once we found a fingerprint we can auth to (ANY), select it as clientfp
2207                 //   once we found a fingerprint in the first list that we know, select it as serverfp
2208
2209                 for(;;)
2210                 {
2211                         p = GetUntilNul(&data_in, &len_in);
2212                         if(!p)
2213                                 break;
2214                         if(!*p)
2215                         {
2216                                 if(!server_can_auth)
2217                                         break; // other protocol message may follow
2218                                 server_can_auth = false;
2219                                 if(clientid >= 0)
2220                                         break;
2221                                 continue;
2222                         }
2223                         for(i = 0; i < MAX_PUBKEYS; ++i)
2224                         {
2225                                 if(pubkeys[i])
2226                                 if(!strcmp(p, pubkeys_fp64[i]))
2227                                 {
2228                                         if(pubkeys_havepriv[i])
2229                                                 if(clientid < 0)
2230                                                         clientid = i;
2231                                         if(server_can_auth)
2232                                                 if(serverid < 0)
2233                                                         if(wantserverid < 0 || i == wantserverid)
2234                                                                 serverid = i;
2235                                 }
2236                         }
2237                         if(clientid >= 0 && serverid >= 0)
2238                                 break;
2239                 }
2240
2241                 // if stored host key is not found:
2242                 if(wantserverid >= 0 && serverid < 0)
2243                         return Crypto_ClientError(data_out, len_out, "Server CA does not match stored host key, refusing to connect");
2244
2245                 if(serverid >= 0 || clientid >= 0)
2246                 {
2247                         // TODO at this point, fill clientside crypto struct!
2248                         MAKE_CDATA;
2249                         CDATA->cdata_id = ++cdata_id;
2250                         CDATA->s = serverid;
2251                         CDATA->c = clientid;
2252                         memset(crypto->dhkey, 0, sizeof(crypto->dhkey));
2253                         strlcpy(CDATA->challenge, challenge, sizeof(CDATA->challenge));
2254                         crypto->client_keyfp[0] = 0;
2255                         crypto->client_idfp[0] = 0;
2256                         crypto->server_keyfp[0] = 0;
2257                         crypto->server_idfp[0] = 0;
2258                         memcpy(CDATA->wantserver_idfp, wantserver_idfp, sizeof(crypto->server_idfp));
2259
2260                         if(CDATA->wantserver_idfp[0]) // if we know a host key, honor its encryption setting
2261                         switch(bound(0, d0_rijndael_dll ? crypto_aeslevel.integer : 0, 3))
2262                         {
2263                                 default: // dummy, never happens, but to make gcc happy...
2264                                 case 0:
2265                                         if(wantserver_aeslevel >= 3)
2266                                                 return Crypto_ServerError(data_out, len_out, "This server requires encryption to be not required (crypto_aeslevel <= 2)", NULL);
2267                                         CDATA->wantserver_aes = false;
2268                                         break;
2269                                 case 1:
2270                                         CDATA->wantserver_aes = (wantserver_aeslevel >= 2);
2271                                         break;
2272                                 case 2:
2273                                         CDATA->wantserver_aes = (wantserver_aeslevel >= 1);
2274                                         break;
2275                                 case 3:
2276                                         if(wantserver_aeslevel <= 0)
2277                                                 return Crypto_ServerError(data_out, len_out, "This server requires encryption to be supported (crypto_aeslevel >= 1, and d0_rijndael library must be present)", NULL);
2278                                         CDATA->wantserver_aes = true;
2279                                         break;
2280                         }
2281
2282                         // build outgoing message
2283                         // append regular stuff
2284                         PutWithNul(&data_out_p, len_out, va(vabuf, sizeof(vabuf), "d0pk\\cnt\\0\\id\\%d\\aeslevel\\%d\\challenge\\%s", CDATA->cdata_id, d0_rijndael_dll ? crypto_aeslevel.integer : 0, challenge));
2285                         PutWithNul(&data_out_p, len_out, serverid >= 0 ? pubkeys_fp64[serverid] : "");
2286                         PutWithNul(&data_out_p, len_out, clientid >= 0 ? pubkeys_fp64[clientid] : "");
2287
2288                         if(clientid >= 0)
2289                         {
2290                                 // I am the client, and my key is ok... so let's set client_keyfp and client_idfp
2291                                 strlcpy(crypto->client_keyfp, pubkeys_fp64[CDATA->c], sizeof(crypto->client_keyfp));
2292                                 strlcpy(crypto->client_idfp, pubkeys_priv_fp64[CDATA->c], sizeof(crypto->client_idfp));
2293                         }
2294
2295                         if(serverid >= 0)
2296                         {
2297                                 if(!CDATA->id)
2298                                         CDATA->id = qd0_blind_id_new();
2299                                 if(!CDATA->id)
2300                                 {
2301                                         CLEAR_CDATA;
2302                                         return Crypto_ClientError(data_out, len_out, "d0_blind_id_new failed");
2303                                 }
2304                                 if(!qd0_blind_id_copy(CDATA->id, pubkeys[CDATA->s]))
2305                                 {
2306                                         CLEAR_CDATA;
2307                                         return Crypto_ClientError(data_out, len_out, "d0_blind_id_copy failed");
2308                                 }
2309                                 CDATA->next_step = 1;
2310                                 *len_out = data_out_p - data_out;
2311                         }
2312                         else if(clientid >= 0)
2313                         {
2314                                 // skip over server auth, perform client auth only
2315                                 if(!CDATA->id)
2316                                         CDATA->id = qd0_blind_id_new();
2317                                 if(!CDATA->id)
2318                                 {
2319                                         CLEAR_CDATA;
2320                                         return Crypto_ClientError(data_out, len_out, "d0_blind_id_new failed");
2321                                 }
2322                                 if(!qd0_blind_id_copy(CDATA->id, pubkeys[CDATA->c]))
2323                                 {
2324                                         CLEAR_CDATA;
2325                                         return Crypto_ClientError(data_out, len_out, "d0_blind_id_copy failed");
2326                                 }
2327                                 if(!qd0_blind_id_authenticate_with_private_id_start(CDATA->id, true, false, "XONOTIC", 8, data_out_p, len_out)) // len_out receives used size by this op
2328                                 {
2329                                         CLEAR_CDATA;
2330                                         return Crypto_ClientError(data_out, len_out, "d0_blind_id_authenticate_with_private_id_start failed");
2331                                 }
2332                                 CDATA->next_step = 5;
2333                                 data_out_p += *len_out;
2334                                 *len_out = data_out_p - data_out;
2335                         }
2336                         else
2337                                 *len_out = data_out_p - data_out;
2338
2339                         return CRYPTO_DISCARD;
2340                 }
2341                 else
2342                 {
2343                         if(wantserver_idfp[0]) // if we know a host key, honor its encryption setting
2344                         if(wantserver_aeslevel >= 3)
2345                                 return Crypto_ClientError(data_out, len_out, "Server insists on encryption, but neither can authenticate to the other");
2346                         return (d0_rijndael_dll && crypto_aeslevel.integer >= 3) ? Crypto_ServerError(data_out, len_out, "This server requires encryption to be not required (crypto_aeslevel <= 2)", NULL) :
2347                                 CRYPTO_NOMATCH;
2348                 }
2349         }
2350         else if(len_in > 5 && !memcmp(string, "d0pk\\", 5) && cls.connect_trying)
2351         {
2352                 const char *cnt;
2353                 int id;
2354                 cnt = InfoString_GetValue(string + 4, "id", infostringvalue, sizeof(infostringvalue));
2355                 id = (cnt ? atoi(cnt) : -1);
2356                 cnt = InfoString_GetValue(string + 4, "cnt", infostringvalue, sizeof(infostringvalue));
2357                 if(!cnt)
2358                         return Crypto_ClientError(data_out, len_out, "d0pk\\ message without cnt");
2359                 GetUntilNul(&data_in, &len_in);
2360                 if(!data_in)
2361                         return Crypto_ClientError(data_out, len_out, "d0pk\\ message without attachment");
2362
2363                 if(!strcmp(cnt, "1"))
2364                 {
2365                         if(id >= 0)
2366                                 if(CDATA->cdata_id != id)
2367                                         return Crypto_SoftServerError(data_out, len_out, va(vabuf, sizeof(vabuf), "Got d0pk\\id\\%d when expecting %d", id, CDATA->cdata_id));
2368                         if(CDATA->next_step != 1)
2369                                 return Crypto_SoftClientError(data_out, len_out, va(vabuf, sizeof(vabuf), "Got d0pk\\cnt\\%s when expecting %d", cnt, CDATA->next_step));
2370
2371                         cls.connect_nextsendtime = max(cls.connect_nextsendtime, realtime + 1); // prevent "hammering"
2372
2373                         if((s = InfoString_GetValue(string + 4, "aes", infostringvalue, sizeof(infostringvalue))))
2374                                 aes = atoi(s);
2375                         else
2376                                 aes = false;
2377                         // we CANNOT toggle the AES status any more!
2378                         // as the server already decided
2379                         if(CDATA->wantserver_idfp[0]) // if we know a host key, honor its encryption setting
2380                         if(!aes && CDATA->wantserver_aes)
2381                         {
2382                                 CLEAR_CDATA;
2383                                 return Crypto_ClientError(data_out, len_out, "Stored host key requires encryption, but server did not enable encryption");
2384                         }
2385                         if(aes && (!d0_rijndael_dll || crypto_aeslevel.integer <= 0))
2386                         {
2387                                 CLEAR_CDATA;
2388                                 return Crypto_ClientError(data_out, len_out, "Server insists on encryption too hard");
2389                         }
2390                         if(!aes && (d0_rijndael_dll && crypto_aeslevel.integer >= 3))
2391                         {
2392                                 CLEAR_CDATA;
2393                                 return Crypto_ClientError(data_out, len_out, "Server insists on plaintext too hard");
2394                         }
2395                         crypto->use_aes = aes != 0;
2396
2397                         PutWithNul(&data_out_p, len_out, va(vabuf, sizeof(vabuf), "d0pk\\cnt\\2\\id\\%d", CDATA->cdata_id));
2398                         if(!qd0_blind_id_authenticate_with_private_id_challenge(CDATA->id, true, false, data_in, len_in, data_out_p, len_out, &status))
2399                         {
2400                                 CLEAR_CDATA;
2401                                 return Crypto_ClientError(data_out, len_out, "d0_blind_id_authenticate_with_private_id_challenge failed");
2402                         }
2403                         CDATA->next_step = 3;
2404                         data_out_p += *len_out;
2405                         *len_out = data_out_p - data_out;
2406                         return CRYPTO_DISCARD;
2407                 }
2408                 else if(!strcmp(cnt, "3"))
2409                 {
2410                         static char msgbuf[32];
2411                         size_t msgbuflen = sizeof(msgbuf);
2412                         size_t fpbuflen;
2413
2414                         if(id >= 0)
2415                                 if(CDATA->cdata_id != id)
2416                                         return Crypto_SoftServerError(data_out, len_out, va(vabuf, sizeof(vabuf), "Got d0pk\\id\\%d when expecting %d", id, CDATA->cdata_id));
2417                         if(CDATA->next_step != 3)
2418                                 return Crypto_SoftClientError(data_out, len_out, va(vabuf, sizeof(vabuf), "Got d0pk\\cnt\\%s when expecting %d", cnt, CDATA->next_step));
2419
2420                         cls.connect_nextsendtime = max(cls.connect_nextsendtime, realtime + 1); // prevent "hammering"
2421
2422                         if(!qd0_blind_id_authenticate_with_private_id_verify(CDATA->id, data_in, len_in, msgbuf, &msgbuflen, &status))
2423                         {
2424                                 CLEAR_CDATA;
2425                                 return Crypto_ClientError(data_out, len_out, "d0_blind_id_authenticate_with_private_id_verify failed (server authentication error)");
2426                         }
2427                         if(status)
2428                                 strlcpy(crypto->server_keyfp, pubkeys_fp64[CDATA->s], sizeof(crypto->server_keyfp));
2429                         else
2430                                 crypto->server_keyfp[0] = 0;
2431                         memset(crypto->server_idfp, 0, sizeof(crypto->server_idfp));
2432                         fpbuflen = FP64_SIZE;
2433                         if(!qd0_blind_id_fingerprint64_public_id(CDATA->id, crypto->server_idfp, &fpbuflen))
2434                         {
2435                                 CLEAR_CDATA;
2436                                 return Crypto_ClientError(data_out, len_out, "d0_blind_id_fingerprint64_public_id failed");
2437                         }
2438                         if(CDATA->wantserver_idfp[0])
2439                         if(memcmp(CDATA->wantserver_idfp, crypto->server_idfp, sizeof(crypto->server_idfp)))
2440                         {
2441                                 CLEAR_CDATA;
2442                                 return Crypto_ClientError(data_out, len_out, "Server ID does not match stored host key, refusing to connect");
2443                         }
2444                         fpbuflen = DHKEY_SIZE;
2445                         if(!qd0_blind_id_sessionkey_public_id(CDATA->id, (char *) crypto->dhkey, &fpbuflen))
2446                         {
2447                                 CLEAR_CDATA;
2448                                 return Crypto_ClientError(data_out, len_out, "d0_blind_id_sessionkey_public_id failed");
2449                         }
2450
2451                         // cache the server key
2452                         Crypto_StoreHostKey(&cls.connect_address, va(vabuf, sizeof(vabuf), "%d %s@%s", crypto->use_aes ? 1 : 0, crypto->server_idfp, pubkeys_fp64[CDATA->s]), false);
2453
2454                         if(CDATA->c >= 0)
2455                         {
2456                                 // client will auth next
2457                                 PutWithNul(&data_out_p, len_out, va(vabuf, sizeof(vabuf), "d0pk\\cnt\\4\\id\\%d", CDATA->cdata_id));
2458                                 if(!qd0_blind_id_copy(CDATA->id, pubkeys[CDATA->c]))
2459                                 {
2460                                         CLEAR_CDATA;
2461                                         return Crypto_ClientError(data_out, len_out, "d0_blind_id_copy failed");
2462                                 }
2463                                 if(!qd0_blind_id_authenticate_with_private_id_start(CDATA->id, true, false, "XONOTIC", 8, data_out_p, len_out)) // len_out receives used size by this op
2464                                 {
2465                                         CLEAR_CDATA;
2466                                         return Crypto_ClientError(data_out, len_out, "d0_blind_id_authenticate_with_private_id_start failed");
2467                                 }
2468                                 CDATA->next_step = 5;
2469                                 data_out_p += *len_out;
2470                                 *len_out = data_out_p - data_out;
2471                                 return CRYPTO_DISCARD;
2472                         }
2473                         else
2474                         {
2475                                 // session key is FINISHED (no server part is to be expected)! By this, all keys are set up
2476                                 crypto->authenticated = true;
2477                                 CDATA->next_step = 0;
2478                                 // assume we got the empty challenge to finish the protocol
2479                                 PutWithNul(&data_out_p, len_out, "challenge ");
2480                                 *len_out = data_out_p - data_out;
2481                                 --*len_out; // remove NUL terminator
2482                                 return CRYPTO_REPLACE;
2483                         }
2484                 }
2485                 else if(!strcmp(cnt, "5"))
2486                 {
2487                         size_t fpbuflen;
2488                         unsigned char dhkey[DHKEY_SIZE];
2489                         int i;
2490
2491                         if(id >= 0)
2492                                 if(CDATA->cdata_id != id)
2493                                         return Crypto_SoftServerError(data_out, len_out, va(vabuf, sizeof(vabuf), "Got d0pk\\id\\%d when expecting %d", id, CDATA->cdata_id));
2494                         if(CDATA->next_step != 5)
2495                                 return Crypto_SoftClientError(data_out, len_out, va(vabuf, sizeof(vabuf), "Got d0pk\\cnt\\%s when expecting %d", cnt, CDATA->next_step));
2496
2497                         cls.connect_nextsendtime = max(cls.connect_nextsendtime, realtime + 1); // prevent "hammering"
2498
2499                         if(CDATA->s < 0) // only if server didn't auth
2500                         {
2501                                 if((s = InfoString_GetValue(string + 4, "aes", infostringvalue, sizeof(infostringvalue))))
2502                                         aes = atoi(s);
2503                                 else
2504                                         aes = false;
2505                                 if(CDATA->wantserver_idfp[0]) // if we know a host key, honor its encryption setting
2506                                 if(!aes && CDATA->wantserver_aes)
2507                                 {
2508                                         CLEAR_CDATA;
2509                                         return Crypto_ClientError(data_out, len_out, "Stored host key requires encryption, but server did not enable encryption");
2510                                 }
2511                                 if(aes && (!d0_rijndael_dll || crypto_aeslevel.integer <= 0))
2512                                 {
2513                                         CLEAR_CDATA;
2514                                         return Crypto_ClientError(data_out, len_out, "Server insists on encryption too hard");
2515                                 }
2516                                 if(!aes && (d0_rijndael_dll && crypto_aeslevel.integer >= 3))
2517                                 {
2518                                         CLEAR_CDATA;
2519                                         return Crypto_ClientError(data_out, len_out, "Server insists on plaintext too hard");
2520                                 }
2521                                 crypto->use_aes = aes != 0;
2522                         }
2523
2524                         PutWithNul(&data_out_p, len_out, va(vabuf, sizeof(vabuf), "d0pk\\cnt\\6\\id\\%d", CDATA->cdata_id));
2525                         if(!qd0_blind_id_authenticate_with_private_id_response(CDATA->id, data_in, len_in, data_out_p, len_out))
2526                         {
2527                                 CLEAR_CDATA;
2528                                 return Crypto_ClientError(data_out, len_out, "d0_blind_id_authenticate_with_private_id_response failed");
2529                         }
2530                         fpbuflen = DHKEY_SIZE;
2531                         if(!qd0_blind_id_sessionkey_public_id(CDATA->id, (char *) dhkey, &fpbuflen))
2532                         {
2533                                 CLEAR_CDATA;
2534                                 return Crypto_ClientError(data_out, len_out, "d0_blind_id_sessionkey_public_id failed");
2535                         }
2536                         // XOR the two DH keys together to make one
2537                         for(i = 0; i < DHKEY_SIZE; ++i)
2538                                 crypto->dhkey[i] ^= dhkey[i];
2539                         // session key is FINISHED! By this, all keys are set up
2540                         crypto->authenticated = true;
2541                         CDATA->next_step = 0;
2542                         data_out_p += *len_out;
2543                         *len_out = data_out_p - data_out;
2544                         return CRYPTO_DISCARD;
2545                 }
2546                 return Crypto_SoftClientError(data_out, len_out, "Got unknown d0_blind_id message from server");
2547         }
2548
2549         return CRYPTO_NOMATCH;
2550 }
2551
2552 size_t Crypto_SignData(const void *data, size_t datasize, int keyid, void *signed_data, size_t signed_size)
2553 {
2554         if(keyid < 0 || keyid >= MAX_PUBKEYS)
2555                 return 0;
2556         if(!pubkeys_havepriv[keyid])
2557                 return 0;
2558         if(qd0_blind_id_sign_with_private_id_sign(pubkeys[keyid], true, false, (const char *)data, datasize, (char *)signed_data, &signed_size))
2559                 return signed_size;
2560         return 0;
2561 }
2562
2563 size_t Crypto_SignDataDetached(const void *data, size_t datasize, int keyid, void *signed_data, size_t signed_size)
2564 {
2565         if(keyid < 0 || keyid >= MAX_PUBKEYS)
2566                 return 0;
2567         if(!pubkeys_havepriv[keyid])
2568                 return 0;
2569         if(qd0_blind_id_sign_with_private_id_sign_detached(pubkeys[keyid], true, false, (const char *)data, datasize, (char *)signed_data, &signed_size))
2570                 return signed_size;
2571         return 0;
2572 }