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
 151 #else
 152
 153 // d0_blind_id interface
 154 #define D0_EXPORT
 155 #ifdef __GNUC__
 156 #define D0_WARN_UNUSED_RESULT __attribute__((warn_unused_result))
 157 #else
 158 #define D0_WARN_UNUSED_RESULT
 159 #endif
 160 #define D0_BOOL int
 161
 162 typedef void *(d0_malloc_t)(size_t len);
 163 typedef void (d0_free_t)(void *p);
 164 typedef void *(d0_createmutex_t)(void);
 165 typedef void (d0_destroymutex_t)(void *);
 166 typedef int (d0_lockmutex_t)(void *); // zero on success
 167 typedef int (d0_unlockmutex_t)(void *); // zero on success
 168
 169 typedef struct d0_blind_id_s d0_blind_id_t;
 170 typedef D0_BOOL (*d0_fastreject_function) (const d0_blind_id_t *ctx, void *pass);
 171 static D0_EXPORT D0_WARN_UNUSED_RESULT d0_blind_id_t *(*qd0_blind_id_new) (void);
 172 static D0_EXPORT void (*qd0_blind_id_free) (d0_blind_id_t *a);
 173 //static D0_EXPORT void (*qd0_blind_id_clear) (d0_blind_id_t *ctx);
 174 static D0_EXPORT D0_WARN_UNUSED_RESULT D0_BOOL (*qd0_blind_id_copy) (d0_blind_id_t *ctx, const d0_blind_id_t *src);
 175 //static D0_EXPORT D0_WARN_UNUSED_RESULT D0_BOOL (*qd0_blind_id_generate_private_key) (d0_blind_id_t *ctx, int k);
 176 //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);
 177 //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);
 178 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);
 179 //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);
 180 //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);
 181 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);
 182 //static D0_EXPORT D0_WARN_UNUSED_RESULT D0_BOOL (*qd0_blind_id_generate_private_id_modulus) (d0_blind_id_t *ctx);
 183 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);
 184 //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);
 185 static D0_EXPORT D0_WARN_UNUSED_RESULT D0_BOOL (*qd0_blind_id_generate_private_id_start) (d0_blind_id_t *ctx);
 186 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);
 187 //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);
 188 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);
 189 //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);
 190 //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);
 191 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);
 192 //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);
 193 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);
 194 //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);
 195 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);
 196 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);
 197 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);
 198 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);
 199 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);
 200 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
 201 static D0_EXPORT D0_WARN_UNUSED_RESULT D0_BOOL (*qd0_blind_id_INITIALIZE) (void);
 202 static D0_EXPORT void (*qd0_blind_id_SHUTDOWN) (void);
 203 static D0_EXPORT void (*qd0_blind_id_util_sha256) (char *out, const char *in, size_t n);
 204 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);
 205 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);
 206 static D0_EXPORT void (*qd0_blind_id_setmallocfuncs)(d0_malloc_t *m, d0_free_t *f);
 207 static D0_EXPORT void (*qd0_blind_id_setmutexfuncs)(d0_createmutex_t *c, d0_destroymutex_t *d, d0_lockmutex_t *l, d0_unlockmutex_t *u);
 208 static dllfunction_t d0_blind_id_funcs[] =
 209 {
 210         {"d0_blind_id_new", (void **) &qd0_blind_id_new},
 211         {"d0_blind_id_free", (void **) &qd0_blind_id_free},
 212         //{"d0_blind_id_clear", (void **) &qd0_blind_id_clear},
 213         {"d0_blind_id_copy", (void **) &qd0_blind_id_copy},
 214         //{"d0_blind_id_generate_private_key", (void **) &qd0_blind_id_generate_private_key},
 215         //{"d0_blind_id_generate_private_key_fastreject", (void **) &qd0_blind_id_generate_private_key_fastreject},
 216         //{"d0_blind_id_read_private_key", (void **) &qd0_blind_id_read_private_key},
 217         {"d0_blind_id_read_public_key", (void **) &qd0_blind_id_read_public_key},
 218         //{"d0_blind_id_write_private_key", (void **) &qd0_blind_id_write_private_key},
 219         //{"d0_blind_id_write_public_key", (void **) &qd0_blind_id_write_public_key},
 220         {"d0_blind_id_fingerprint64_public_key", (void **) &qd0_blind_id_fingerprint64_public_key},
 221         //{"d0_blind_id_generate_private_id_modulus", (void **) &qd0_blind_id_generate_private_id_modulus},
 222         {"d0_blind_id_read_private_id_modulus", (void **) &qd0_blind_id_read_private_id_modulus},
 223         //{"d0_blind_id_write_private_id_modulus", (void **) &qd0_blind_id_write_private_id_modulus},
 224         {"d0_blind_id_generate_private_id_start", (void **) &qd0_blind_id_generate_private_id_start},
 225         {"d0_blind_id_generate_private_id_request", (void **) &qd0_blind_id_generate_private_id_request},
 226         //{"d0_blind_id_answer_private_id_request", (void **) &qd0_blind_id_answer_private_id_request},
 227         {"d0_blind_id_finish_private_id_request", (void **) &qd0_blind_id_finish_private_id_request},
 228         //{"d0_blind_id_read_private_id_request_camouflage", (void **) &qd0_blind_id_read_private_id_request_camouflage},
 229         //{"d0_blind_id_write_private_id_request_camouflage", (void **) &qd0_blind_id_write_private_id_request_camouflage},
 230         {"d0_blind_id_read_private_id", (void **) &qd0_blind_id_read_private_id},
 231         //{"d0_blind_id_read_public_id", (void **) &qd0_blind_id_read_public_id},
 232         {"d0_blind_id_write_private_id", (void **) &qd0_blind_id_write_private_id},
 233         //{"d0_blind_id_write_public_id", (void **) &qd0_blind_id_write_public_id},
 234         {"d0_blind_id_authenticate_with_private_id_start", (void **) &qd0_blind_id_authenticate_with_private_id_start},
 235         {"d0_blind_id_authenticate_with_private_id_challenge", (void **) &qd0_blind_id_authenticate_with_private_id_challenge},
 236         {"d0_blind_id_authenticate_with_private_id_response", (void **) &qd0_blind_id_authenticate_with_private_id_response},
 237         {"d0_blind_id_authenticate_with_private_id_verify", (void **) &qd0_blind_id_authenticate_with_private_id_verify},
 238         {"d0_blind_id_fingerprint64_public_id", (void **) &qd0_blind_id_fingerprint64_public_id},
 239         {"d0_blind_id_sessionkey_public_id", (void **) &qd0_blind_id_sessionkey_public_id},
 240         {"d0_blind_id_INITIALIZE", (void **) &qd0_blind_id_INITIALIZE},
 241         {"d0_blind_id_SHUTDOWN", (void **) &qd0_blind_id_SHUTDOWN},
 242         {"d0_blind_id_util_sha256", (void **) &qd0_blind_id_util_sha256},
 243         {"d0_blind_id_sign_with_private_id_sign", (void **) &qd0_blind_id_sign_with_private_id_sign},
 244         {"d0_blind_id_sign_with_private_id_sign_detached", (void **) &qd0_blind_id_sign_with_private_id_sign_detached},
 245         {"d0_blind_id_setmallocfuncs", (void **) &qd0_blind_id_setmallocfuncs},
 246         {"d0_blind_id_setmutexfuncs", (void **) &qd0_blind_id_setmutexfuncs},
 247         {NULL, NULL}
 248 };
 249 // end of d0_blind_id interface
 250
 251 static dllhandle_t d0_blind_id_dll = NULL;
 252 static qboolean Crypto_OpenLibrary (void)
 253 {
 254         const char* dllnames [] =
 255         {
 256 #if defined(WIN32)
 257                 "libd0_blind_id-0.dll",
 258 #elif defined(MACOSX)
 259                 "libd0_blind_id.0.dylib",
 260 #else
 261                 "libd0_blind_id.so.0",
 262                 "libd0_blind_id.so", // FreeBSD
 263 #endif
 264                 NULL
 265         };
 266
 267         // Already loaded?
 268         if (d0_blind_id_dll)
 269                 return true;
 270
 271         // Load the DLL
 272         return Sys_LoadLibrary (dllnames, &d0_blind_id_dll, d0_blind_id_funcs);
 273 }
 274
 275 static void Crypto_CloseLibrary (void)
 276 {
 277         Sys_UnloadLibrary (&d0_blind_id_dll);
 278 }
 279
 280 #endif
 281
 282 #ifdef CRYPTO_RIJNDAEL_STATIC
 283
 284 #include <d0_blind_id/d0_rijndael.h>
 285
 286 #define d0_rijndael_dll 1
 287 #define Crypto_Rijndael_OpenLibrary() true
 288 #define Crypto_Rijndael_CloseLibrary()
 289
 290 #define qd0_rijndael_setup_encrypt d0_rijndael_setup_encrypt
 291 #define qd0_rijndael_setup_decrypt d0_rijndael_setup_decrypt
 292 #define qd0_rijndael_encrypt d0_rijndael_encrypt
 293 #define qd0_rijndael_decrypt d0_rijndael_decrypt
 294
 295 #else
 296
 297 // no need to do the #define dance here, as the upper part declares out macros either way
 298
 299 D0_EXPORT int (*qd0_rijndael_setup_encrypt) (unsigned long *rk, const unsigned char *key,
 300   int keybits);
 301 D0_EXPORT int (*qd0_rijndael_setup_decrypt) (unsigned long *rk, const unsigned char *key,
 302   int keybits);
 303 D0_EXPORT void (*qd0_rijndael_encrypt) (const unsigned long *rk, int nrounds,
 304   const unsigned char plaintext[16], unsigned char ciphertext[16]);
 305 D0_EXPORT void (*qd0_rijndael_decrypt) (const unsigned long *rk, int nrounds,
 306   const unsigned char ciphertext[16], unsigned char plaintext[16]);
 307 #define D0_RIJNDAEL_KEYLENGTH(keybits) ((keybits)/8)
 308 #define D0_RIJNDAEL_RKLENGTH(keybits)  ((keybits)/8+28)
 309 #define D0_RIJNDAEL_NROUNDS(keybits)   ((keybits)/32+6)
 310 static dllfunction_t d0_rijndael_funcs[] =
 311 {
 312         {"d0_rijndael_setup_decrypt", (void **) &qd0_rijndael_setup_decrypt},
 313         {"d0_rijndael_setup_encrypt", (void **) &qd0_rijndael_setup_encrypt},
 314         {"d0_rijndael_decrypt", (void **) &qd0_rijndael_decrypt},
 315         {"d0_rijndael_encrypt", (void **) &qd0_rijndael_encrypt},
 316         {NULL, NULL}
 317 };
 318 // end of d0_blind_id interface
 319
 320 static dllhandle_t d0_rijndael_dll = NULL;
 321 static qboolean Crypto_Rijndael_OpenLibrary (void)
 322 {
 323         const char* dllnames [] =
 324         {
 325 #if defined(WIN32)
 326                 "libd0_rijndael-0.dll",
 327 #elif defined(MACOSX)
 328                 "libd0_rijndael.0.dylib",
 329 #else
 330                 "libd0_rijndael.so.0",
 331                 "libd0_rijndael.so", // FreeBSD
 332 #endif
 333                 NULL
 334         };
 335
 336         // Already loaded?
 337         if (d0_rijndael_dll)
 338                 return true;
 339
 340         // Load the DLL
 341         return Sys_LoadLibrary (dllnames, &d0_rijndael_dll, d0_rijndael_funcs);
 342 }
 343
 344 static void Crypto_Rijndael_CloseLibrary (void)
 345 {
 346         Sys_UnloadLibrary (&d0_rijndael_dll);
 347 }
 348
 349 #endif
 350
 351 // various helpers
 352 void sha256(unsigned char *out, const unsigned char *in, int n)
 353 {
 354         qd0_blind_id_util_sha256((char *) out, (const char *) in, n);
 355 }
 356
 357 static size_t Crypto_LoadFile(const char *path, char *buf, size_t nmax, qboolean inuserdir)
 358 {
 359         char vabuf[1024];
 360         qfile_t *f = NULL;
 361         fs_offset_t n;
 362         if(inuserdir)
 363                 f = FS_SysOpen(va(vabuf, sizeof(vabuf), "%s%s", *fs_userdir ? fs_userdir : fs_basedir, path), "rb", false);
 364         else
 365                 f = FS_SysOpen(va(vabuf, sizeof(vabuf), "%s%s", fs_basedir, path), "rb", false);
 366         if(!f)
 367                 return 0;
 368         n = FS_Read(f, buf, nmax);
 369         if(n < 0)
 370                 n = 0;
 371         FS_Close(f);
 372         return (size_t) n;
 373 }
 374
 375 static qboolean PutWithNul(char **data, size_t *len, const char *str)
 376 {
 377         // invariant: data points to insertion point
 378         size_t l = strlen(str);
 379         if(l >= *len)
 380                 return false;
 381         memcpy(*data, str, l+1);
 382         *data += l+1;
 383         *len -= l+1;
 384         return true;
 385 }
 386
 387 static const char *GetUntilNul(const char **data, size_t *len)
 388 {
 389         // invariant: data points to next character to take
 390         const char *data_save = *data;
 391         size_t n;
 392         const char *p;
 393
 394         if(!*data)
 395                 return NULL;
 396
 397         if(!*len)
 398         {
 399                 *data = NULL;
 400                 return NULL;
 401         }
 402
 403         p = (const char *) memchr(*data, 0, *len);
 404         if(!p) // no terminating NUL
 405         {
 406                 *data = NULL;
 407                 *len = 0;
 408                 return NULL;
 409         }
 410         else
 411         {
 412                 n = (p - *data) + 1;
 413                 *len -= n;
 414                 *data += n;
 415                 if(*len == 0)
 416                         *data = NULL;
 417                 return (const char *) data_save;
 418         }
 419         *data = NULL;
 420         return NULL;
 421 }
 422
 423 // d0pk reading
 424 static d0_blind_id_t *Crypto_ReadPublicKey(char *buf, size_t len)
 425 {
 426         d0_blind_id_t *pk = NULL;
 427         const char *p[2];
 428         size_t l[2];
 429         if(Crypto_ParsePack(buf, len, FOURCC_D0PK, p, l, 2))
 430         {
 431                 pk = qd0_blind_id_new();
 432                 if(pk)
 433                         if(qd0_blind_id_read_public_key(pk, p[0], l[0]))
 434                                 if(qd0_blind_id_read_private_id_modulus(pk, p[1], l[1]))
 435                                         return pk;
 436         }
 437         if(pk)
 438                 qd0_blind_id_free(pk);
 439         return NULL;
 440 }
 441
 442 // d0si reading
 443 static qboolean Crypto_AddPrivateKey(d0_blind_id_t *pk, char *buf, size_t len)
 444 {
 445         const char *p[1];
 446         size_t l[1];
 447         if(Crypto_ParsePack(buf, len, FOURCC_D0SI, p, l, 1))
 448         {
 449                 if(qd0_blind_id_read_private_id(pk, p[0], l[0]))
 450                         return true;
 451         }
 452         return false;
 453 }
 454
 455 #define MAX_PUBKEYS 16
 456 static d0_blind_id_t *pubkeys[MAX_PUBKEYS];
 457 static char pubkeys_fp64[MAX_PUBKEYS][FP64_SIZE+1];
 458 static qboolean pubkeys_havepriv[MAX_PUBKEYS];
 459 static char pubkeys_priv_fp64[MAX_PUBKEYS][FP64_SIZE+1];
 460 static char challenge_append[1400];
 461 static size_t challenge_append_length;
 462
 463 static int keygen_i = -1;
 464 static char keygen_buf[8192];
 465
 466 #define MAX_CRYPTOCONNECTS 16
 467 #define CRYPTOCONNECT_NONE 0
 468 #define CRYPTOCONNECT_PRECONNECT 1
 469 #define CRYPTOCONNECT_CONNECT 2
 470 #define CRYPTOCONNECT_RECONNECT 3
 471 #define CRYPTOCONNECT_DUPLICATE 4
 472 typedef struct server_cryptoconnect_s
 473 {
 474         double lasttime;
 475         lhnetaddress_t address;
 476         crypto_t crypto;
 477         int next_step;
 478 }
 479 server_cryptoconnect_t;
 480 static server_cryptoconnect_t cryptoconnects[MAX_CRYPTOCONNECTS];
 481
 482 static int cdata_id = 0;
 483 typedef struct
 484 {
 485         d0_blind_id_t *id;
 486         int s, c;
 487         int next_step;
 488         char challenge[2048];
 489         char wantserver_idfp[FP64_SIZE+1];
 490         qboolean wantserver_aes;
 491         int cdata_id;
 492 }
 493 crypto_data_t;
 494
 495 // crypto specific helpers
 496 #define CDATA ((crypto_data_t *) crypto->data)
 497 #define MAKE_CDATA if(!crypto->data) crypto->data = Z_Malloc(sizeof(crypto_data_t))
 498 #define CLEAR_CDATA if(crypto->data) { if(CDATA->id) qd0_blind_id_free(CDATA->id); Z_Free(crypto->data); } crypto->data = NULL
 499
 500 static crypto_t *Crypto_ServerFindInstance(lhnetaddress_t *peeraddress, qboolean allow_create)
 501 {
 502         crypto_t *crypto;
 503         int i, best;
 504
 505         if(!d0_blind_id_dll)
 506                 return NULL; // no support
 507
 508         for(i = 0; i < MAX_CRYPTOCONNECTS; ++i)
 509                 if(LHNETADDRESS_Compare(peeraddress, &cryptoconnects[i].address))
 510                         break;
 511         if(i < MAX_CRYPTOCONNECTS && (allow_create || cryptoconnects[i].crypto.data))
 512         {
 513                 crypto = &cryptoconnects[i].crypto;
 514                 cryptoconnects[i].lasttime = realtime;
 515                 return crypto;
 516         }
 517         if(!allow_create)
 518                 return NULL;
 519         best = 0;
 520         for(i = 1; i < MAX_CRYPTOCONNECTS; ++i)
 521                 if(cryptoconnects[i].lasttime < cryptoconnects[best].lasttime)
 522                         best = i;
 523         crypto = &cryptoconnects[best].crypto;
 524         cryptoconnects[best].lasttime = realtime;
 525         memcpy(&cryptoconnects[best].address, peeraddress, sizeof(cryptoconnects[best].address));
 526         CLEAR_CDATA;
 527         return crypto;
 528 }
 529
 530 qboolean Crypto_ServerFinishInstance(crypto_t *out, crypto_t *crypto)
 531 {
 532         // no check needed here (returned pointers are only used in prefilled fields)
 533         if(!crypto || !crypto->authenticated)
 534         {
 535                 Con_Printf("Passed an invalid crypto connect instance\n");
 536                 memset(out, 0, sizeof(*out));
 537                 return false;
 538         }
 539         CLEAR_CDATA;
 540         memcpy(out, crypto, sizeof(*out));
 541         memset(crypto, 0, sizeof(crypto));
 542         return true;
 543 }
 544
 545 crypto_t *Crypto_ServerGetInstance(lhnetaddress_t *peeraddress)
 546 {
 547         // no check needed here (returned pointers are only used in prefilled fields)
 548         return Crypto_ServerFindInstance(peeraddress, false);
 549 }
 550
 551 typedef struct crypto_storedhostkey_s
 552 {
 553         struct crypto_storedhostkey_s *next;
 554         lhnetaddress_t addr;
 555         int keyid;
 556         char idfp[FP64_SIZE+1];
 557         int aeslevel;
 558 }
 559 crypto_storedhostkey_t;
 560 static crypto_storedhostkey_t *crypto_storedhostkey_hashtable[CRYPTO_HOSTKEY_HASHSIZE];
 561
 562 static void Crypto_InitHostKeys(void)
 563 {
 564         int i;
 565         for(i = 0; i < CRYPTO_HOSTKEY_HASHSIZE; ++i)
 566                 crypto_storedhostkey_hashtable[i] = NULL;
 567 }
 568
 569 static void Crypto_ClearHostKeys(void)
 570 {
 571         int i;
 572         crypto_storedhostkey_t *hk, *hkn;
 573         for(i = 0; i < CRYPTO_HOSTKEY_HASHSIZE; ++i)
 574         {
 575                 for(hk = crypto_storedhostkey_hashtable[i]; hk; hk = hkn)
 576                 {
 577                         hkn = hk->next;
 578                         Z_Free(hk);
 579                 }
 580                 crypto_storedhostkey_hashtable[i] = NULL;
 581         }
 582 }
 583
 584 static qboolean Crypto_ClearHostKey(lhnetaddress_t *peeraddress)
 585 {
 586         char buf[128];
 587         int hashindex;
 588         crypto_storedhostkey_t **hkp;
 589         qboolean found = false;
 590
 591         LHNETADDRESS_ToString(peeraddress, buf, sizeof(buf), 1);
 592         hashindex = CRC_Block((const unsigned char *) buf, strlen(buf)) % CRYPTO_HOSTKEY_HASHSIZE;
 593         for(hkp = &crypto_storedhostkey_hashtable[hashindex]; *hkp && LHNETADDRESS_Compare(&((*hkp)->addr), peeraddress); hkp = &((*hkp)->next));
 594
 595         if(*hkp)
 596         {
 597                 crypto_storedhostkey_t *hk = *hkp;
 598                 *hkp = hk->next;
 599                 Z_Free(hk);
 600                 found = true;
 601         }
 602
 603         return found;
 604 }
 605
 606 static void Crypto_StoreHostKey(lhnetaddress_t *peeraddress, const char *keystring, qboolean complain)
 607 {
 608         char buf[128];
 609         int hashindex;
 610         crypto_storedhostkey_t *hk;
 611         int keyid;
 612         char idfp[FP64_SIZE+1];
 613         int aeslevel;
 614
 615         if(!d0_blind_id_dll)
 616                 return;
 617
 618         // syntax of keystring:
 619         // aeslevel id@key id@key ...
 620
 621         if(!*keystring)
 622                 return;
 623         aeslevel = bound(0, *keystring - '0', 3);
 624         while(*keystring && *keystring != ' ')
 625                 ++keystring;
 626
 627         keyid = -1;
 628         while(*keystring && keyid < 0)
 629         {
 630                 // id@key
 631                 const char *idstart, *idend, *keystart, *keyend;
 632                 ++keystring; // skip the space
 633                 idstart = keystring;
 634                 while(*keystring && *keystring != ' ' && *keystring != '@')
 635                         ++keystring;
 636                 idend = keystring;
 637                 if(!*keystring)
 638                         break;
 639                 ++keystring;
 640                 keystart = keystring;
 641                 while(*keystring && *keystring != ' ')
 642                         ++keystring;
 643                 keyend = keystring;
 644
 645                 if(idend - idstart == FP64_SIZE && keyend - keystart == FP64_SIZE)
 646                 {
 647                         for(keyid = 0; keyid < MAX_PUBKEYS; ++keyid)
 648                                 if(pubkeys[keyid])
 649                                         if(!memcmp(pubkeys_fp64[keyid], keystart, FP64_SIZE))
 650                                         {
 651                                                 memcpy(idfp, idstart, FP64_SIZE);
 652                                                 idfp[FP64_SIZE] = 0;
 653                                                 break;
 654                                         }
 655                         if(keyid >= MAX_PUBKEYS)
 656                                 keyid = -1;
 657                 }
 658         }
 659
 660         if(keyid < 0)
 661                 return;
 662
 663         LHNETADDRESS_ToString(peeraddress, buf, sizeof(buf), 1);
 664         hashindex = CRC_Block((const unsigned char *) buf, strlen(buf)) % CRYPTO_HOSTKEY_HASHSIZE;
 665         for(hk = crypto_storedhostkey_hashtable[hashindex]; hk && LHNETADDRESS_Compare(&hk->addr, peeraddress); hk = hk->next);
 666
 667         if(hk)
 668         {
 669                 if(complain)
 670                 {
 671                         if(hk->keyid != keyid || memcmp(hk->idfp, idfp, FP64_SIZE+1))
 672                                 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);
 673                         if(hk->aeslevel > aeslevel)
 674                                 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);
 675                 }
 676                 hk->aeslevel = max(aeslevel, hk->aeslevel);
 677                 return;
 678         }
 679
 680         // great, we did NOT have it yet
 681         hk = (crypto_storedhostkey_t *) Z_Malloc(sizeof(*hk));
 682         memcpy(&hk->addr, peeraddress, sizeof(hk->addr));
 683         hk->keyid = keyid;
 684         memcpy(hk->idfp, idfp, FP64_SIZE+1);
 685         hk->next = crypto_storedhostkey_hashtable[hashindex];
 686         hk->aeslevel = aeslevel;
 687         crypto_storedhostkey_hashtable[hashindex] = hk;
 688 }
 689
 690 qboolean Crypto_RetrieveHostKey(lhnetaddress_t *peeraddress, int *keyid, char *keyfp, size_t keyfplen, char *idfp, size_t idfplen, int *aeslevel)
 691 {
 692         char buf[128];
 693         int hashindex;
 694         crypto_storedhostkey_t *hk;
 695
 696         if(!d0_blind_id_dll)
 697                 return false;
 698
 699         LHNETADDRESS_ToString(peeraddress, buf, sizeof(buf), 1);
 700         hashindex = CRC_Block((const unsigned char *) buf, strlen(buf)) % CRYPTO_HOSTKEY_HASHSIZE;
 701         for(hk = crypto_storedhostkey_hashtable[hashindex]; hk && LHNETADDRESS_Compare(&hk->addr, peeraddress); hk = hk->next);
 702
 703         if(!hk)
 704                 return false;
 705
 706         if(keyid)
 707                 *keyid = hk->keyid;
 708         if(keyfp)
 709                 strlcpy(keyfp, pubkeys_fp64[hk->keyid], keyfplen);
 710         if(idfp)
 711                 strlcpy(idfp, hk->idfp, idfplen);
 712         if(aeslevel)
 713                 *aeslevel = hk->aeslevel;
 714
 715         return true;
 716 }
 717 int Crypto_RetrieveLocalKey(int keyid, char *keyfp, size_t keyfplen, char *idfp, size_t idfplen) // return value: -1 if more to come, +1 if valid, 0 if end of list
 718 {
 719         if(keyid < 0 || keyid >= MAX_PUBKEYS)
 720                 return 0;
 721         if(keyfp)
 722                 *keyfp = 0;
 723         if(idfp)
 724                 *idfp = 0;
 725         if(!pubkeys[keyid])
 726                 return -1;
 727         if(keyfp)
 728                 strlcpy(keyfp, pubkeys_fp64[keyid], keyfplen);
 729         if(idfp)
 730                 if(pubkeys_havepriv[keyid])
 731                         strlcpy(idfp, pubkeys_priv_fp64[keyid], keyfplen);
 732         return 1;
 733 }
 734 // end
 735
 736 // init/shutdown code
 737 static void Crypto_BuildChallengeAppend(void)
 738 {
 739         char *p, *lengthptr, *startptr;
 740         size_t n;
 741         int i;
 742         p = challenge_append;
 743         n = sizeof(challenge_append);
 744         Crypto_UnLittleLong(p, PROTOCOL_VLEN);
 745         p += 4;
 746         n -= 4;
 747         lengthptr = p;
 748         Crypto_UnLittleLong(p, 0);
 749         p += 4;
 750         n -= 4;
 751         Crypto_UnLittleLong(p, PROTOCOL_D0_BLIND_ID);
 752         p += 4;
 753         n -= 4;
 754         startptr = p;
 755         for(i = 0; i < MAX_PUBKEYS; ++i)
 756                 if(pubkeys_havepriv[i])
 757                         PutWithNul(&p, &n, pubkeys_fp64[i]);
 758         PutWithNul(&p, &n, "");
 759         for(i = 0; i < MAX_PUBKEYS; ++i)
 760                 if(!pubkeys_havepriv[i] && pubkeys[i])
 761                         PutWithNul(&p, &n, pubkeys_fp64[i]);
 762         Crypto_UnLittleLong(lengthptr, p - startptr);
 763         challenge_append_length = p - challenge_append;
 764 }
 765
 766 void Crypto_LoadKeys(void)
 767 {
 768         char buf[8192];
 769         size_t len, len2;
 770         int i;
 771         char vabuf[1024];
 772
 773         if(!d0_blind_id_dll) // don't if we can't
 774                 return;
 775
 776         if(crypto_idstring) // already loaded? then not
 777                 return;
 778
 779         Host_LockSession(); // we use the session ID here
 780
 781         SV_LockThreadMutex();
 782
 783         // load keys
 784         // note: we are just a CLIENT
 785         // so we load:
 786         //   PUBLIC KEYS to accept (including modulus)
 787         //   PRIVATE KEY of user
 788
 789         crypto_idstring = NULL;
 790         dpsnprintf(crypto_idstring_buf, sizeof(crypto_idstring_buf), "%d", d0_rijndael_dll ? crypto_aeslevel.integer : 0);
 791         for(i = 0; i < MAX_PUBKEYS; ++i)
 792         {
 793                 memset(pubkeys_fp64[i], 0, sizeof(pubkeys_fp64[i]));
 794                 memset(pubkeys_priv_fp64[i], 0, sizeof(pubkeys_fp64[i]));
 795                 pubkeys_havepriv[i] = false;
 796                 len = Crypto_LoadFile(va(vabuf, sizeof(vabuf), "key_%d.d0pk", i), buf, sizeof(buf), false);
 797                 if((pubkeys[i] = Crypto_ReadPublicKey(buf, len)))
 798                 {
 799                         len2 = FP64_SIZE;
 800                         if(qd0_blind_id_fingerprint64_public_key(pubkeys[i], pubkeys_fp64[i], &len2)) // keeps final NUL
 801                         {
 802                                 Con_Printf("Loaded public key key_%d.d0pk (fingerprint: %s)\n", i, pubkeys_fp64[i]);
 803                                 len = Crypto_LoadFile(va(vabuf, sizeof(vabuf), "key_%d.d0si%s", i, sessionid.string), buf, sizeof(buf), true);
 804                                 if(len)
 805                                 {
 806                                         if(Crypto_AddPrivateKey(pubkeys[i], buf, len))
 807                                         {
 808                                                 len2 = FP64_SIZE;
 809                                                 if(qd0_blind_id_fingerprint64_public_id(pubkeys[i], pubkeys_priv_fp64[i], &len2)) // keeps final NUL
 810                                                 {
 811                                                         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]);
 812                                                         pubkeys_havepriv[i] = true;
 813                                                         strlcat(crypto_idstring_buf, va(vabuf, sizeof(vabuf), " %s@%s", pubkeys_priv_fp64[i], pubkeys_fp64[i]), sizeof(crypto_idstring_buf));
 814                                                 }
 815                                                 else
 816                                                 {
 817                                                         // can't really happen
 818                                                         // but nothing leaked here
 819                                                 }
 820                                         }
 821                                 }
 822                         }
 823                         else
 824                         {
 825                                 // can't really happen
 826                                 qd0_blind_id_free(pubkeys[i]);
 827                                 pubkeys[i] = NULL;
 828                         }
 829                 }
 830         }
 831         crypto_idstring = crypto_idstring_buf;
 832
 833         keygen_i = -1;
 834         Crypto_BuildChallengeAppend();
 835
 836         // find a good prefix length for all the keys we know (yes, algorithm is not perfect yet, may yield too long prefix length)
 837         crypto_keyfp_recommended_length = 0;
 838         memset(buf+256, 0, MAX_PUBKEYS + MAX_PUBKEYS);
 839         while(crypto_keyfp_recommended_length < FP64_SIZE)
 840         {
 841                 memset(buf, 0, 256);
 842                 for(i = 0; i < MAX_PUBKEYS; ++i)
 843                         if(pubkeys[i])
 844                         {
 845                                 if(!buf[256 + i])
 846                                         ++buf[(unsigned char) pubkeys_fp64[i][crypto_keyfp_recommended_length]];
 847                                 if(pubkeys_havepriv[i])
 848                                         if(!buf[256 + MAX_PUBKEYS + i])
 849                                                 ++buf[(unsigned char) pubkeys_priv_fp64[i][crypto_keyfp_recommended_length]];
 850                         }
 851                 for(i = 0; i < MAX_PUBKEYS; ++i)
 852                         if(pubkeys[i])
 853                         {
 854                                 if(!buf[256 + i])
 855                                         if(buf[(unsigned char) pubkeys_fp64[i][crypto_keyfp_recommended_length]] < 2)
 856                                                 buf[256 + i] = 1;
 857                                 if(pubkeys_havepriv[i])
 858                                         if(!buf[256 + MAX_PUBKEYS + i])
 859                                                 if(buf[(unsigned char) pubkeys_priv_fp64[i][crypto_keyfp_recommended_length]] < 2)
 860                                                         buf[256 + MAX_PUBKEYS + i] = 1;
 861                         }
 862                 ++crypto_keyfp_recommended_length;
 863                 for(i = 0; i < MAX_PUBKEYS; ++i)
 864                         if(pubkeys[i])
 865                         {
 866                                 if(!buf[256 + i])
 867                                         break;
 868                                 if(pubkeys_havepriv[i])
 869                                         if(!buf[256 + MAX_PUBKEYS + i])
 870                                                 break;
 871                         }
 872                 if(i >= MAX_PUBKEYS)
 873                         break;
 874         }
 875         if(crypto_keyfp_recommended_length < 7)
 876                 crypto_keyfp_recommended_length = 7;
 877
 878         SV_UnlockThreadMutex();
 879 }
 880
 881 static void Crypto_UnloadKeys(void)
 882 {
 883         int i;
 884
 885         SV_LockThreadMutex();
 886
 887         keygen_i = -1;
 888         for(i = 0; i < MAX_PUBKEYS; ++i)
 889         {
 890                 if(pubkeys[i])
 891                         qd0_blind_id_free(pubkeys[i]);
 892                 pubkeys[i] = NULL;
 893                 pubkeys_havepriv[i] = false;
 894                 memset(pubkeys_fp64[i], 0, sizeof(pubkeys_fp64[i]));
 895                 memset(pubkeys_priv_fp64[i], 0, sizeof(pubkeys_fp64[i]));
 896                 challenge_append_length = 0;
 897         }
 898         crypto_idstring = NULL;
 899
 900         SV_UnlockThreadMutex();
 901 }
 902
 903 static mempool_t *cryptomempool;
 904
 905 #ifdef __cplusplus
 906 extern "C"
 907 {
 908 #endif
 909 static void *Crypto_d0_malloc(size_t len)
 910 {
 911         return Mem_Alloc(cryptomempool, len);
 912 }
 913
 914 static void Crypto_d0_free(void *p)
 915 {
 916         Mem_Free(p);
 917 }
 918
 919 static void *Crypto_d0_createmutex(void)
 920 {
 921         return Thread_CreateMutex();
 922 }
 923
 924 static void Crypto_d0_destroymutex(void *m)
 925 {
 926         Thread_DestroyMutex(m);
 927 }
 928
 929 static int Crypto_d0_lockmutex(void *m)
 930 {
 931         return Thread_LockMutex(m);
 932 }
 933
 934 static int Crypto_d0_unlockmutex(void *m)
 935 {
 936         return Thread_UnlockMutex(m);
 937 }
 938 #ifdef __cplusplus
 939 }
 940 #endif
 941
 942 void Crypto_Shutdown(void)
 943 {
 944         crypto_t *crypto;
 945         int i;
 946
 947         Crypto_Rijndael_CloseLibrary();
 948
 949         if(d0_blind_id_dll)
 950         {
 951                 // free memory
 952                 for(i = 0; i < MAX_CRYPTOCONNECTS; ++i)
 953                 {
 954                         crypto = &cryptoconnects[i].crypto;
 955                         CLEAR_CDATA;
 956                 }
 957                 memset(cryptoconnects, 0, sizeof(cryptoconnects));
 958                 crypto = &cls.crypto;
 959                 CLEAR_CDATA;
 960
 961                 Crypto_UnloadKeys();
 962
 963                 qd0_blind_id_SHUTDOWN();
 964
 965                 Crypto_CloseLibrary();
 966         }
 967
 968         Mem_FreePool(&cryptomempool);
 969 }
 970
 971 void Crypto_Init(void)
 972 {
 973         cryptomempool = Mem_AllocPool("crypto", 0, NULL);
 974
 975         if(!Crypto_OpenLibrary())
 976                 return;
 977
 978         qd0_blind_id_setmallocfuncs(Crypto_d0_malloc, Crypto_d0_free);
 979         if (Thread_HasThreads())
 980                 qd0_blind_id_setmutexfuncs(Crypto_d0_createmutex, Crypto_d0_destroymutex, Crypto_d0_lockmutex, Crypto_d0_unlockmutex);
 981
 982         if(!qd0_blind_id_INITIALIZE())
 983         {
 984                 Crypto_Rijndael_CloseLibrary();
 985                 Crypto_CloseLibrary();
 986                 Con_Printf("libd0_blind_id initialization FAILED, cryptography support has been disabled\n");
 987                 return;
 988         }
 989
 990         Crypto_Rijndael_OpenLibrary(); // if this fails, it's uncritical
 991
 992         Crypto_InitHostKeys();
 993 }
 994 // end
 995
 996 qboolean Crypto_Available(void)
 997 {
 998         if(!d0_blind_id_dll)
 999                 return false;
1000         return true;
1001 }
1002
1003 // keygen code
1004 static void Crypto_KeyGen_Finished(int code, size_t length_received, unsigned char *buffer, void *cbdata)
1005 {
1006         const char *p[1];
1007         size_t l[1];
1008         static char buf[8192];
1009         static char buf2[8192];
1010         size_t bufsize, buf2size;
1011         qfile_t *f = NULL;
1012         d0_blind_id_t *ctx, *ctx2;
1013         D0_BOOL status;
1014         size_t len2;
1015         char vabuf[1024];
1016
1017         SV_LockThreadMutex();
1018
1019         if(!d0_blind_id_dll)
1020         {
1021                 Con_Print("libd0_blind_id DLL not found, this command is inactive.\n");
1022                 keygen_i = -1;
1023                 SV_UnlockThreadMutex();
1024                 return;
1025         }
1026
1027         if(keygen_i >= MAX_PUBKEYS || !pubkeys[keygen_i])
1028         {
1029                 Con_Printf("overflow of keygen_i\n");
1030                 keygen_i = -1;
1031                 SV_UnlockThreadMutex();
1032                 return;
1033         }
1034         if(keygen_i < 0)
1035         {
1036                 Con_Printf("Unexpected response from keygen server:\n");
1037                 Com_HexDumpToConsole(buffer, length_received);
1038                 SV_UnlockThreadMutex();
1039                 return;
1040         }
1041         if(!Crypto_ParsePack((const char *) buffer, length_received, FOURCC_D0IR, p, l, 1))
1042         {
1043                 if(length_received >= 5 && Crypto_LittleLong((const char *) buffer) == FOURCC_D0ER)
1044                 {
1045                         Con_Printf("Error response from keygen server: %.*s\n", (int)(length_received - 5), buffer + 5);
1046                 }
1047                 else
1048                 {
1049                         Con_Printf("Invalid response from keygen server:\n");
1050                         Com_HexDumpToConsole(buffer, length_received);
1051                 }
1052                 keygen_i = -1;
1053                 SV_UnlockThreadMutex();
1054                 return;
1055         }
1056         if(!qd0_blind_id_finish_private_id_request(pubkeys[keygen_i], p[0], l[0]))
1057         {
1058                 Con_Printf("d0_blind_id_finish_private_id_request failed\n");
1059                 keygen_i = -1;
1060                 SV_UnlockThreadMutex();
1061                 return;
1062         }
1063
1064         // verify the key we just got (just in case)
1065         ctx = qd0_blind_id_new();
1066         if(!ctx)
1067         {
1068                 Con_Printf("d0_blind_id_new failed\n");
1069                 keygen_i = -1;
1070                 SV_UnlockThreadMutex();
1071                 return;
1072         }
1073         ctx2 = qd0_blind_id_new();
1074         if(!ctx2)
1075         {
1076                 Con_Printf("d0_blind_id_new failed\n");
1077                 qd0_blind_id_free(ctx);
1078                 keygen_i = -1;
1079                 SV_UnlockThreadMutex();
1080                 return;
1081         }
1082         if(!qd0_blind_id_copy(ctx, pubkeys[keygen_i]))
1083         {
1084                 Con_Printf("d0_blind_id_copy failed\n");
1085                 qd0_blind_id_free(ctx);
1086                 qd0_blind_id_free(ctx2);
1087                 keygen_i = -1;
1088                 SV_UnlockThreadMutex();
1089                 return;
1090         }
1091         if(!qd0_blind_id_copy(ctx2, pubkeys[keygen_i]))
1092         {
1093                 Con_Printf("d0_blind_id_copy failed\n");
1094                 qd0_blind_id_free(ctx);
1095                 qd0_blind_id_free(ctx2);
1096                 keygen_i = -1;
1097                 SV_UnlockThreadMutex();
1098                 return;
1099         }
1100         bufsize = sizeof(buf);
1101         if(!qd0_blind_id_authenticate_with_private_id_start(ctx, 1, 1, "hello world", 11, buf, &bufsize))
1102         {
1103                 Con_Printf("d0_blind_id_authenticate_with_private_id_start failed\n");
1104                 qd0_blind_id_free(ctx);
1105                 qd0_blind_id_free(ctx2);
1106                 keygen_i = -1;
1107                 SV_UnlockThreadMutex();
1108                 return;
1109         }
1110         buf2size = sizeof(buf2);
1111         if(!qd0_blind_id_authenticate_with_private_id_challenge(ctx2, 1, 1, buf, bufsize, buf2, &buf2size, &status) || !status)
1112         {
1113                 Con_Printf("d0_blind_id_authenticate_with_private_id_challenge failed (server does not have the requested private key)\n");
1114                 qd0_blind_id_free(ctx);
1115                 qd0_blind_id_free(ctx2);
1116                 keygen_i = -1;
1117                 SV_UnlockThreadMutex();
1118                 return;
1119         }
1120         bufsize = sizeof(buf);
1121         if(!qd0_blind_id_authenticate_with_private_id_response(ctx, buf2, buf2size, buf, &bufsize))
1122         {
1123                 Con_Printf("d0_blind_id_authenticate_with_private_id_response failed\n");
1124                 qd0_blind_id_free(ctx);
1125                 qd0_blind_id_free(ctx2);
1126                 keygen_i = -1;
1127                 SV_UnlockThreadMutex();
1128                 return;
1129         }
1130         buf2size = sizeof(buf2);
1131         if(!qd0_blind_id_authenticate_with_private_id_verify(ctx2, buf, bufsize, buf2, &buf2size, &status) || !status)
1132         {
1133                 Con_Printf("d0_blind_id_authenticate_with_private_id_verify failed (server does not have the requested private key)\n");
1134                 qd0_blind_id_free(ctx);
1135                 qd0_blind_id_free(ctx2);
1136                 keygen_i = -1;
1137                 SV_UnlockThreadMutex();
1138                 return;
1139         }
1140         qd0_blind_id_free(ctx);
1141         qd0_blind_id_free(ctx2);
1142
1143         // we have a valid key now!
1144         // make the rest of crypto.c know that
1145         len2 = FP64_SIZE;
1146         if(qd0_blind_id_fingerprint64_public_id(pubkeys[keygen_i], pubkeys_priv_fp64[keygen_i], &len2)) // keeps final NUL
1147         {
1148                 Con_Printf("Received private ID key_%d.d0pk (public key fingerprint: %s)\n", keygen_i, pubkeys_priv_fp64[keygen_i]);
1149                 pubkeys_havepriv[keygen_i] = true;
1150                 strlcat(crypto_idstring_buf, va(vabuf, sizeof(vabuf), " %s@%s", pubkeys_priv_fp64[keygen_i], pubkeys_fp64[keygen_i]), sizeof(crypto_idstring_buf));
1151                 crypto_idstring = crypto_idstring_buf;
1152                 Crypto_BuildChallengeAppend();
1153         }
1154         // write the key to disk
1155         p[0] = buf;
1156         l[0] = sizeof(buf);
1157         if(!qd0_blind_id_write_private_id(pubkeys[keygen_i], buf, &l[0]))
1158         {
1159                 Con_Printf("d0_blind_id_write_private_id failed\n");
1160                 keygen_i = -1;
1161                 SV_UnlockThreadMutex();
1162                 return;
1163         }
1164         if(!(buf2size = Crypto_UnParsePack(buf2, sizeof(buf2), FOURCC_D0SI, p, l, 1)))
1165         {
1166                 Con_Printf("Crypto_UnParsePack failed\n");
1167                 keygen_i = -1;
1168                 SV_UnlockThreadMutex();
1169                 return;
1170         }
1171
1172         FS_CreatePath(va(vabuf, sizeof(vabuf), "%skey_%d.d0si%s", *fs_userdir ? fs_userdir : fs_basedir, keygen_i, sessionid.string));
1173         f = FS_SysOpen(va(vabuf, sizeof(vabuf), "%skey_%d.d0si%s", *fs_userdir ? fs_userdir : fs_basedir, keygen_i, sessionid.string), "wb", false);
1174         if(!f)
1175         {
1176                 Con_Printf("Cannot open key_%d.d0si%s\n", keygen_i, sessionid.string);
1177                 keygen_i = -1;
1178                 SV_UnlockThreadMutex();
1179                 return;
1180         }
1181         FS_Write(f, buf2, buf2size);
1182         FS_Close(f);
1183
1184         Con_Printf("Saved to key_%d.d0si%s\n", keygen_i, sessionid.string);
1185         keygen_i = -1;
1186         SV_UnlockThreadMutex();
1187 }
1188
1189 static void Crypto_KeyGen_f(void)
1190 {
1191         int i;
1192         const char *p[1];
1193         size_t l[1];
1194         static char buf[8192];
1195         static char buf2[8192];
1196         size_t buf2l, buf2pos;
1197         if(!d0_blind_id_dll)
1198         {
1199                 Con_Print("libd0_blind_id DLL not found, this command is inactive.\n");
1200                 return;
1201         }
1202         if(Cmd_Argc() != 3)
1203         {
1204                 Con_Printf("usage:\n%s id url\n", Cmd_Argv(0));
1205                 return;
1206         }
1207         SV_LockThreadMutex();
1208         Crypto_LoadKeys();
1209         i = atoi(Cmd_Argv(1));
1210         if(!pubkeys[i])
1211         {
1212                 Con_Printf("there is no public key %d\n", i);
1213                 SV_UnlockThreadMutex();
1214                 return;
1215         }
1216         if(pubkeys_havepriv[i])
1217         {
1218                 Con_Printf("there is already a private key for %d\n", i);
1219                 SV_UnlockThreadMutex();
1220                 return;
1221         }
1222         if(keygen_i >= 0)
1223         {
1224                 Con_Printf("there is already a keygen run on the way\n");
1225                 SV_UnlockThreadMutex();
1226                 return;
1227         }
1228         keygen_i = i;
1229         if(!qd0_blind_id_generate_private_id_start(pubkeys[keygen_i]))
1230         {
1231                 Con_Printf("d0_blind_id_start failed\n");
1232                 keygen_i = -1;
1233                 SV_UnlockThreadMutex();
1234                 return;
1235         }
1236         p[0] = buf;
1237         l[0] = sizeof(buf);
1238         if(!qd0_blind_id_generate_private_id_request(pubkeys[keygen_i], buf, &l[0]))
1239         {
1240                 Con_Printf("d0_blind_id_generate_private_id_request failed\n");
1241                 keygen_i = -1;
1242                 SV_UnlockThreadMutex();
1243                 return;
1244         }
1245         buf2pos = strlen(Cmd_Argv(2));
1246         memcpy(buf2, Cmd_Argv(2), buf2pos);
1247         if(!(buf2l = Crypto_UnParsePack(buf2 + buf2pos, sizeof(buf2) - buf2pos - 1, FOURCC_D0IQ, p, l, 1)))
1248         {
1249                 Con_Printf("Crypto_UnParsePack failed\n");
1250                 keygen_i = -1;
1251                 SV_UnlockThreadMutex();
1252                 return;
1253         }
1254         if(!(buf2l = base64_encode((unsigned char *) (buf2 + buf2pos), buf2l, sizeof(buf2) - buf2pos - 1)))
1255         {
1256                 Con_Printf("base64_encode failed\n");
1257                 keygen_i = -1;
1258                 SV_UnlockThreadMutex();
1259                 return;
1260         }
1261         buf2l += buf2pos;
1262         buf[buf2l] = 0;
1263         if(!Curl_Begin_ToMemory(buf2, 0, (unsigned char *) keygen_buf, sizeof(keygen_buf), Crypto_KeyGen_Finished, NULL))
1264         {
1265                 Con_Printf("curl failed\n");
1266                 keygen_i = -1;
1267                 SV_UnlockThreadMutex();
1268                 return;
1269         }
1270         Con_Printf("key generation in progress\n");
1271         SV_UnlockThreadMutex();
1272 }
1273 // end
1274
1275 // console commands
1276 static void Crypto_Reload_f(void)
1277 {
1278         Crypto_ClearHostKeys();
1279         Crypto_UnloadKeys();
1280         Crypto_LoadKeys();
1281 }
1282
1283 static void Crypto_Keys_f(void)
1284 {
1285         int i;
1286         if(!d0_blind_id_dll)
1287         {
1288                 Con_Print("libd0_blind_id DLL not found, this command is inactive.\n");
1289                 return;
1290         }
1291         for(i = 0; i < MAX_PUBKEYS; ++i)
1292         {
1293                 if(pubkeys[i])
1294                 {
1295                         Con_Printf("%2d: public key key_%d.d0pk (fingerprint: %s)\n", i, i, pubkeys_fp64[i]);
1296                         if(pubkeys_havepriv[i])
1297                                 Con_Printf("    private ID key_%d.d0si%s (public key fingerprint: %s)\n", i, sessionid.string, pubkeys_priv_fp64[i]);
1298                 }
1299         }
1300 }
1301
1302 static void Crypto_HostKeys_f(void)
1303 {
1304         int i;
1305         crypto_storedhostkey_t *hk;
1306         char buf[128];
1307
1308         if(!d0_blind_id_dll)
1309         {
1310                 Con_Print("libd0_blind_id DLL not found, this command is inactive.\n");
1311                 return;
1312         }
1313         for(i = 0; i < CRYPTO_HOSTKEY_HASHSIZE; ++i)
1314         {
1315                 for(hk = crypto_storedhostkey_hashtable[i]; hk; hk = hk->next)
1316                 {
1317                         LHNETADDRESS_ToString(&hk->addr, buf, sizeof(buf), 1);
1318                         Con_Printf("%d %s@%.*s %s\n",
1319                                         hk->aeslevel,
1320                                         hk->idfp,
1321                                         crypto_keyfp_recommended_length, pubkeys_fp64[hk->keyid],
1322                                         buf);
1323                 }
1324         }
1325 }
1326
1327 static void Crypto_HostKey_Clear_f(void)
1328 {
1329         lhnetaddress_t addr;
1330         int i;
1331
1332         if(!d0_blind_id_dll)
1333         {
1334                 Con_Print("libd0_blind_id DLL not found, this command is inactive.\n");
1335                 return;
1336         }
1337
1338         for(i = 1; i < Cmd_Argc(); ++i)
1339         {
1340                 LHNETADDRESS_FromString(&addr, Cmd_Argv(i), 26000);
1341                 if(Crypto_ClearHostKey(&addr))
1342                 {
1343                         Con_Printf("cleared host key for %s\n", Cmd_Argv(i));
1344                 }
1345         }
1346 }
1347
1348 void Crypto_Init_Commands(void)
1349 {
1350         if(d0_blind_id_dll)
1351         {
1352                 Cmd_AddCommand("crypto_reload", Crypto_Reload_f, "reloads cryptographic keys");
1353                 Cmd_AddCommand("crypto_keygen", Crypto_KeyGen_f, "generates and saves a cryptographic key");
1354                 Cmd_AddCommand("crypto_keys", Crypto_Keys_f, "lists the loaded keys");
1355                 Cmd_AddCommand("crypto_hostkeys", Crypto_HostKeys_f, "lists the cached host keys");
1356                 Cmd_AddCommand("crypto_hostkey_clear", Crypto_HostKey_Clear_f, "clears a cached host key");
1357                 Cvar_RegisterVariable(&crypto_developer);
1358                 if(d0_rijndael_dll)
1359                         Cvar_RegisterVariable(&crypto_aeslevel);
1360                 else
1361                         crypto_aeslevel.integer = 0; // make sure
1362                 Cvar_RegisterVariable(&crypto_servercpupercent);
1363                 Cvar_RegisterVariable(&crypto_servercpumaxtime);
1364                 Cvar_RegisterVariable(&crypto_servercpudebug);
1365         }
1366 }
1367 // end
1368
1369 // AES encryption
1370 static void aescpy(unsigned char *key, const unsigned char *iv, unsigned char *dst, const unsigned char *src, size_t len)
1371 {
1372         const unsigned char *xorpos = iv;
1373         unsigned char xorbuf[16];
1374         unsigned long rk[D0_RIJNDAEL_RKLENGTH(DHKEY_SIZE * 8)];
1375         size_t i;
1376         qd0_rijndael_setup_encrypt(rk, key, DHKEY_SIZE * 8);
1377         while(len > 16)
1378         {
1379                 for(i = 0; i < 16; ++i)
1380                         xorbuf[i] = src[i] ^ xorpos[i];
1381                 qd0_rijndael_encrypt(rk, D0_RIJNDAEL_NROUNDS(DHKEY_SIZE * 8), xorbuf, dst);
1382                 xorpos = dst;
1383                 len -= 16;
1384                 src += 16;
1385                 dst += 16;
1386         }
1387         if(len > 0)
1388         {
1389                 for(i = 0; i < len; ++i)
1390                         xorbuf[i] = src[i] ^ xorpos[i];
1391                 for(; i < 16; ++i)
1392                         xorbuf[i] = xorpos[i];
1393                 qd0_rijndael_encrypt(rk, D0_RIJNDAEL_NROUNDS(DHKEY_SIZE * 8), xorbuf, dst);
1394         }
1395 }
1396 static void seacpy(unsigned char *key, const unsigned char *iv, unsigned char *dst, const unsigned char *src, size_t len)
1397 {
1398         const unsigned char *xorpos = iv;
1399         unsigned char xorbuf[16];
1400         unsigned long rk[D0_RIJNDAEL_RKLENGTH(DHKEY_SIZE * 8)];
1401         size_t i;
1402         qd0_rijndael_setup_decrypt(rk, key, DHKEY_SIZE * 8);
1403         while(len > 16)
1404         {
1405                 qd0_rijndael_decrypt(rk, D0_RIJNDAEL_NROUNDS(DHKEY_SIZE * 8), src, xorbuf);
1406                 for(i = 0; i < 16; ++i)
1407                         dst[i] = xorbuf[i] ^ xorpos[i];
1408                 xorpos = src;
1409                 len -= 16;
1410                 src += 16;
1411                 dst += 16;
1412         }
1413         if(len > 0)
1414         {
1415                 qd0_rijndael_decrypt(rk, D0_RIJNDAEL_NROUNDS(DHKEY_SIZE * 8), src, xorbuf);
1416                 for(i = 0; i < len; ++i)
1417                         dst[i] = xorbuf[i] ^ xorpos[i];
1418         }
1419 }
1420
1421 // NOTE: we MUST avoid the following begins of the packet:
1422 //   1. 0xFF, 0xFF, 0xFF, 0xFF
1423 //   2. 0x80, 0x00, length/256, length%256
1424 // this luckily does NOT affect AES mode, where the first byte always is in the range from 0x00 to 0x0F
1425 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)
1426 {
1427         unsigned char h[32];
1428         int i;
1429         if(crypto->authenticated)
1430         {
1431                 if(crypto->use_aes)
1432                 {
1433                         // AES packet = 1 byte length overhead, 15 bytes from HMAC-SHA-256, data, 0..15 bytes padding
1434                         // 15 bytes HMAC-SHA-256 (112bit) suffice as the attacker can't do more than forge a random-looking packet
1435                         // HMAC is needed to not leak information about packet content
1436                         if(developer_networking.integer)
1437                         {
1438                                 Con_Print("To be encrypted:\n");
1439                                 Com_HexDumpToConsole((const unsigned char *) data_src, len_src);
1440                         }
1441                         if(len_src + 32 > len || !HMAC_SHA256_32BYTES(h, (const unsigned char *) data_src, len_src, crypto->dhkey, DHKEY_SIZE))
1442                         {
1443                                 Con_Printf("Crypto_EncryptPacket failed (not enough space: %d bytes in, %d bytes out)\n", (int) len_src, (int) len);
1444                                 return NULL;
1445                         }
1446                         *len_dst = ((len_src + 15) / 16) * 16 + 16; // add 16 for HMAC, then round to 16-size for AES
1447                         ((unsigned char *) data_dst)[0] = *len_dst - len_src;
1448                         memcpy(((unsigned char *) data_dst)+1, h, 15);
1449                         aescpy(crypto->dhkey, (const unsigned char *) data_dst, ((unsigned char *) data_dst) + 16, (const unsigned char *) data_src, len_src);
1450                         //                    IV                                dst                                src                               len
1451                 }
1452                 else
1453                 {
1454                         // HMAC packet = 16 bytes HMAC-SHA-256 (truncated to 128 bits), data
1455                         if(len_src + 16 > len || !HMAC_SHA256_32BYTES(h, (const unsigned char *) data_src, len_src, crypto->dhkey, DHKEY_SIZE))
1456                         {
1457                                 Con_Printf("Crypto_EncryptPacket failed (not enough space: %d bytes in, %d bytes out)\n", (int) len_src, (int) len);
1458                                 return NULL;
1459                         }
1460                         *len_dst = len_src + 16;
1461                         memcpy(data_dst, h, 16);
1462                         memcpy(((unsigned char *) data_dst) + 16, (unsigned char *) data_src, len_src);
1463
1464                         // handle the "avoid" conditions:
1465                         i = BuffBigLong((unsigned char *) data_dst);
1466                         if(
1467                                 (i == (int)0xFFFFFFFF) // avoid QW control packet
1468                                 ||
1469                                 (i == (int)0x80000000 + (int)*len_dst) // avoid NQ control packet
1470                         )
1471                                 *(unsigned char *)data_dst ^= 0x80; // this will ALWAYS fix it
1472                 }
1473                 return data_dst;
1474         }
1475         else
1476         {
1477                 *len_dst = len_src;
1478                 return data_src;
1479         }
1480 }
1481
1482 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)
1483 {
1484         unsigned char h[32];
1485         int i;
1486
1487         // silently handle non-crypto packets
1488         i = BuffBigLong((unsigned char *) data_src);
1489         if(
1490                 (i == (int)0xFFFFFFFF) // avoid QW control packet
1491                 ||
1492                 (i == (int)0x80000000 + (int)len_src) // avoid NQ control packet
1493         )
1494                 return NULL;
1495
1496         if(crypto->authenticated)
1497         {
1498                 if(crypto->use_aes)
1499                 {
1500                         if(len_src < 16 || ((len_src - 16) % 16))
1501                         {
1502                                 Con_Printf("Crypto_DecryptPacket failed (not enough space: %d bytes in, %d bytes out)\n", (int) len_src, (int) len);
1503                                 return NULL;
1504                         }
1505                         *len_dst = len_src - ((unsigned char *) data_src)[0];
1506                         if(len < *len_dst || *len_dst > len_src - 16)
1507                         {
1508                                 Con_Printf("Crypto_DecryptPacket failed (not enough space: %d bytes in, %d->%d bytes out)\n", (int) len_src, (int) *len_dst, (int) len);
1509                                 return NULL;
1510                         }
1511                         seacpy(crypto->dhkey, (unsigned char *) data_src, (unsigned char *) data_dst, ((const unsigned char *) data_src) + 16, *len_dst);
1512                         //                    IV                          dst                         src                                      len
1513                         if(!HMAC_SHA256_32BYTES(h, (const unsigned char *) data_dst, *len_dst, crypto->dhkey, DHKEY_SIZE))
1514                         {
1515                                 Con_Printf("HMAC fail\n");
1516                                 return NULL;
1517                         }
1518                         if(memcmp(((const unsigned char *) data_src)+1, h, 15)) // ignore first byte, used for length
1519                         {
1520                                 Con_Printf("HMAC mismatch\n");
1521                                 return NULL;
1522                         }
1523                         if(developer_networking.integer)
1524                         {
1525                                 Con_Print("Decrypted:\n");
1526                                 Com_HexDumpToConsole((const unsigned char *) data_dst, *len_dst);
1527                         }
1528                         return data_dst; // no need to copy
1529                 }
1530                 else
1531                 {
1532                         if(len_src < 16)
1533                         {
1534                                 Con_Printf("Crypto_DecryptPacket failed (not enough space: %d bytes in, %d bytes out)\n", (int) len_src, (int) len);
1535                                 return NULL;
1536                         }
1537                         *len_dst = len_src - 16;
1538                         if(len < *len_dst)
1539                         {
1540                                 Con_Printf("Crypto_DecryptPacket failed (not enough space: %d bytes in, %d->%d bytes out)\n", (int) len_src, (int) *len_dst, (int) len);
1541                                 return NULL;
1542                         }
1543                         //memcpy(data_dst, data_src + 16, *len_dst);
1544                         if(!HMAC_SHA256_32BYTES(h, ((const unsigned char *) data_src) + 16, *len_dst, crypto->dhkey, DHKEY_SIZE))
1545                         {
1546                                 Con_Printf("HMAC fail\n");
1547                                 Com_HexDumpToConsole((const unsigned char *) data_src, len_src);
1548                                 return NULL;
1549                         }
1550
1551                         if(memcmp((const unsigned char *) data_src, h, 16)) // ignore first byte, used for length
1552                         {
1553                                 // undo the "avoid conditions"
1554                                 if(
1555                                                 (i == (int)0x7FFFFFFF) // avoided QW control packet
1556                                                 ||
1557                                                 (i == (int)0x00000000 + (int)len_src) // avoided NQ control packet
1558                                   )
1559                                 {
1560                                         // do the avoidance on the hash too
1561                                         h[0] ^= 0x80;
1562                                         if(memcmp((const unsigned char *) data_src, h, 16)) // ignore first byte, used for length
1563                                         {
1564                                                 Con_Printf("HMAC mismatch\n");
1565                                                 Com_HexDumpToConsole((const unsigned char *) data_src, len_src);
1566                                                 return NULL;
1567                                         }
1568                                 }
1569                                 else
1570                                 {
1571                                         Con_Printf("HMAC mismatch\n");
1572                                         Com_HexDumpToConsole((const unsigned char *) data_src, len_src);
1573                                         return NULL;
1574                                 }
1575                         }
1576                         return ((const unsigned char *) data_src) + 16; // no need to copy, so data_dst is not used
1577                 }
1578         }
1579         else
1580         {
1581                 *len_dst = len_src;
1582                 return data_src;
1583         }
1584 }
1585 // end
1586
1587 const char *Crypto_GetInfoResponseDataString(void)
1588 {
1589         crypto_idstring_buf[0] = '0' + crypto_aeslevel.integer;
1590         return crypto_idstring;
1591 }
1592
1593 // network protocol
1594 qboolean Crypto_ServerAppendToChallenge(const char *data_in, size_t len_in, char *data_out, size_t *len_out, size_t maxlen_out)
1595 {
1596         // cheap op, all is precomputed
1597         if(!d0_blind_id_dll)
1598                 return false; // no support
1599         // append challenge
1600         if(maxlen_out <= *len_out + challenge_append_length)
1601                 return false;
1602         memcpy(data_out + *len_out, challenge_append, challenge_append_length);
1603         *len_out += challenge_append_length;
1604         return false;
1605 }
1606
1607 static int Crypto_ServerError(char *data_out, size_t *len_out, const char *msg, const char *msg_client)
1608 {
1609         if(!msg_client)
1610                 msg_client = msg;
1611         Con_DPrintf("rejecting client: %s\n", msg);
1612         if(*msg_client)
1613                 dpsnprintf(data_out, *len_out, "reject %s", msg_client);
1614         *len_out = strlen(data_out);
1615         return CRYPTO_DISCARD;
1616 }
1617
1618 static int Crypto_SoftServerError(char *data_out, size_t *len_out, const char *msg)
1619 {
1620         *len_out = 0;
1621         Con_DPrintf("%s\n", msg);
1622         return CRYPTO_DISCARD;
1623 }
1624
1625 static int Crypto_ServerParsePacket_Internal(const char *data_in, size_t len_in, char *data_out, size_t *len_out, lhnetaddress_t *peeraddress)
1626 {
1627         // if "connect": reject if in the middle of crypto handshake
1628         crypto_t *crypto = NULL;
1629         char *data_out_p = data_out;
1630         const char *string = data_in;
1631         int aeslevel;
1632         D0_BOOL aes;
1633         D0_BOOL status;
1634         char infostringvalue[MAX_INPUTLINE];
1635         char vabuf[1024];
1636
1637         if(!d0_blind_id_dll)
1638                 return CRYPTO_NOMATCH; // no support
1639
1640         if (len_in > 8 && !memcmp(string, "connect\\", 8) && d0_rijndael_dll && crypto_aeslevel.integer >= 3)
1641         {
1642                 const char *s;
1643                 int i;
1644                 // sorry, we have to verify the challenge here to not reflect network spam
1645
1646                 if (!(s = InfoString_GetValue(string + 4, "challenge", infostringvalue, sizeof(infostringvalue))))
1647                         return CRYPTO_NOMATCH; // will be later accepted if encryption was set up
1648                 // validate the challenge
1649                 for (i = 0;i < MAX_CHALLENGES;i++)
1650                         if(challenge[i].time > 0)
1651                                 if (!LHNETADDRESS_Compare(peeraddress, &challenge[i].address) && !strcmp(challenge[i].string, s))
1652                                         break;
1653                 // if the challenge is not recognized, drop the packet
1654                 if (i == MAX_CHALLENGES) // challenge mismatch is silent
1655                         return CRYPTO_DISCARD; // pre-challenge: rather be silent
1656
1657                 crypto = Crypto_ServerFindInstance(peeraddress, false);
1658                 if(!crypto || !crypto->authenticated)
1659                         return Crypto_ServerError(data_out, len_out, "This server requires authentication and encryption to be supported by your client", NULL);
1660         }
1661         else if(len_in > 5 && !memcmp(string, "d0pk\\", 5) && ((LHNETADDRESS_GetAddressType(peeraddress) == LHNETADDRESSTYPE_LOOP) || sv_public.integer > -3))
1662         {
1663                 const char *cnt, *s, *p;
1664                 int id;
1665                 int clientid = -1, serverid = -1;
1666                 cnt = InfoString_GetValue(string + 4, "id", infostringvalue, sizeof(infostringvalue));
1667                 id = (cnt ? atoi(cnt) : -1);
1668                 cnt = InfoString_GetValue(string + 4, "cnt", infostringvalue, sizeof(infostringvalue));
1669                 if(!cnt)
1670                         return CRYPTO_DISCARD; // pre-challenge: rather be silent
1671                 GetUntilNul(&data_in, &len_in);
1672                 if(!data_in)
1673                         return CRYPTO_DISCARD; // pre-challenge: rather be silent
1674                 if(!strcmp(cnt, "0"))
1675                 {
1676                         int i;
1677                         if (!(s = InfoString_GetValue(string + 4, "challenge", infostringvalue, sizeof(infostringvalue))))
1678                                 return CRYPTO_DISCARD; // pre-challenge: rather be silent
1679                         // validate the challenge
1680                         for (i = 0;i < MAX_CHALLENGES;i++)
1681                                 if(challenge[i].time > 0)
1682                                         if (!LHNETADDRESS_Compare(peeraddress, &challenge[i].address) && !strcmp(challenge[i].string, s))
1683                                                 break;
1684                         // if the challenge is not recognized, drop the packet
1685                         if (i == MAX_CHALLENGES) // challenge mismatch is silent
1686                                 return CRYPTO_DISCARD; // pre-challenge: rather be silent
1687
1688                         if (!(s = InfoString_GetValue(string + 4, "aeslevel", infostringvalue, sizeof(infostringvalue))))
1689                                 aeslevel = 0; // not supported
1690                         else
1691                                 aeslevel = bound(0, atoi(s), 3);
1692                         switch(bound(0, d0_rijndael_dll ? crypto_aeslevel.integer : 0, 3))
1693                         {
1694                                 default: // dummy, never happens, but to make gcc happy...
1695                                 case 0:
1696                                         if(aeslevel >= 3)
1697                                                 return Crypto_ServerError(data_out, len_out, "This server requires encryption to be not required (crypto_aeslevel <= 2)", NULL);
1698                                         aes = false;
1699                                         break;
1700                                 case 1:
1701                                         aes = (aeslevel >= 2);
1702                                         break;
1703                                 case 2:
1704                                         aes = (aeslevel >= 1);
1705                                         break;
1706                                 case 3:
1707                                         if(aeslevel <= 0)
1708                                                 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);
1709                                         aes = true;
1710                                         break;
1711                         }
1712
1713                         p = GetUntilNul(&data_in, &len_in);
1714                         if(p && *p)
1715                         {
1716                                 for(i = 0; i < MAX_PUBKEYS; ++i)
1717                                 {
1718                                         if(pubkeys[i])
1719                                                 if(!strcmp(p, pubkeys_fp64[i]))
1720                                                         if(pubkeys_havepriv[i])
1721                                                                 if(serverid < 0)
1722                                                                         serverid = i;
1723                                 }
1724                                 if(serverid < 0)
1725                                         return Crypto_ServerError(data_out, len_out, "Invalid server key", NULL);
1726                         }
1727                         p = GetUntilNul(&data_in, &len_in);
1728                         if(p && *p)
1729                         {
1730                                 for(i = 0; i < MAX_PUBKEYS; ++i)
1731                                 {
1732                                         if(pubkeys[i])
1733                                                 if(!strcmp(p, pubkeys_fp64[i]))
1734                                                         if(clientid < 0)
1735                                                                 clientid = i;
1736                                 }
1737                                 if(clientid < 0)
1738                                         return Crypto_ServerError(data_out, len_out, "Invalid client key", NULL);
1739                         }
1740
1741                         crypto = Crypto_ServerFindInstance(peeraddress, true);
1742                         if(!crypto)
1743                                 return Crypto_ServerError(data_out, len_out, "Could not create a crypto connect instance", NULL);
1744                         MAKE_CDATA;
1745                         CDATA->cdata_id = id;
1746                         CDATA->s = serverid;
1747                         CDATA->c = clientid;
1748                         memset(crypto->dhkey, 0, sizeof(crypto->dhkey));
1749                         CDATA->challenge[0] = 0;
1750                         crypto->client_keyfp[0] = 0;
1751                         crypto->client_idfp[0] = 0;
1752                         crypto->server_keyfp[0] = 0;
1753                         crypto->server_idfp[0] = 0;
1754                         crypto->use_aes = aes != 0;
1755
1756                         if(CDATA->s >= 0)
1757                         {
1758                                 // I am the server, and my key is ok... so let's set server_keyfp and server_idfp
1759                                 strlcpy(crypto->server_keyfp, pubkeys_fp64[CDATA->s], sizeof(crypto->server_keyfp));
1760                                 strlcpy(crypto->server_idfp, pubkeys_priv_fp64[CDATA->s], sizeof(crypto->server_idfp));
1761
1762                                 if(!CDATA->id)
1763                                         CDATA->id = qd0_blind_id_new();
1764                                 if(!CDATA->id)
1765                                 {
1766                                         CLEAR_CDATA;
1767                                         return Crypto_ServerError(data_out, len_out, "d0_blind_id_new failed", "Internal error");
1768                                 }
1769                                 if(!qd0_blind_id_copy(CDATA->id, pubkeys[CDATA->s]))
1770                                 {
1771                                         CLEAR_CDATA;
1772                                         return Crypto_ServerError(data_out, len_out, "d0_blind_id_copy failed", "Internal error");
1773                                 }
1774                                 PutWithNul(&data_out_p, len_out, va(vabuf, sizeof(vabuf), "d0pk\\cnt\\1\\id\\%d\\aes\\%d", CDATA->cdata_id, crypto->use_aes));
1775                                 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
1776                                 {
1777                                         CLEAR_CDATA;
1778                                         return Crypto_ServerError(data_out, len_out, "d0_blind_id_authenticate_with_private_id_start failed", "Internal error");
1779                                 }
1780                                 CDATA->next_step = 2;
1781                                 data_out_p += *len_out;
1782                                 *len_out = data_out_p - data_out;
1783                                 return CRYPTO_DISCARD;
1784                         }
1785                         else if(CDATA->c >= 0)
1786                         {
1787                                 if(!CDATA->id)
1788                                         CDATA->id = qd0_blind_id_new();
1789                                 if(!CDATA->id)
1790                                 {
1791                                         CLEAR_CDATA;
1792                                         return Crypto_ServerError(data_out, len_out, "d0_blind_id_new failed", "Internal error");
1793                                 }
1794                                 if(!qd0_blind_id_copy(CDATA->id, pubkeys[CDATA->c]))
1795                                 {
1796                                         CLEAR_CDATA;
1797                                         return Crypto_ServerError(data_out, len_out, "d0_blind_id_copy failed", "Internal error");
1798                                 }
1799                                 PutWithNul(&data_out_p, len_out, va(vabuf, sizeof(vabuf), "d0pk\\cnt\\5\\id\\%d\\aes\\%d", CDATA->cdata_id, crypto->use_aes));
1800                                 if(!qd0_blind_id_authenticate_with_private_id_challenge(CDATA->id, true, false, data_in, len_in, data_out_p, len_out, &status))
1801                                 {
1802                                         CLEAR_CDATA;
1803                                         return Crypto_ServerError(data_out, len_out, "d0_blind_id_authenticate_with_private_id_challenge failed", "Internal error");
1804                                 }
1805                                 CDATA->next_step = 6;
1806                                 data_out_p += *len_out;
1807                                 *len_out = data_out_p - data_out;
1808                                 return CRYPTO_DISCARD;
1809                         }
1810                         else
1811                         {
1812                                 CLEAR_CDATA;
1813                                 return Crypto_ServerError(data_out, len_out, "Missing client and server key", NULL);
1814                         }
1815                 }
1816                 else if(!strcmp(cnt, "2"))
1817                 {
1818                         size_t fpbuflen;
1819                         crypto = Crypto_ServerFindInstance(peeraddress, false);
1820                         if(!crypto)
1821                                 return CRYPTO_NOMATCH; // pre-challenge, rather be silent
1822                         if(id >= 0)
1823                                 if(CDATA->cdata_id != id)
1824                                         return Crypto_SoftServerError(data_out, len_out, va(vabuf, sizeof(vabuf), "Got d0pk\\id\\%d when expecting %d", id, CDATA->cdata_id));
1825                         if(CDATA->next_step != 2)
1826                                 return Crypto_SoftServerError(data_out, len_out, va(vabuf, sizeof(vabuf), "Got d0pk\\cnt\\%s when expecting %d", cnt, CDATA->next_step));
1827
1828                         PutWithNul(&data_out_p, len_out, va(vabuf, sizeof(vabuf), "d0pk\\cnt\\3\\id\\%d", CDATA->cdata_id));
1829                         if(!qd0_blind_id_authenticate_with_private_id_response(CDATA->id, data_in, len_in, data_out_p, len_out))
1830                         {
1831                                 CLEAR_CDATA;
1832                                 return Crypto_ServerError(data_out, len_out, "d0_blind_id_authenticate_with_private_id_response failed", "Internal error");
1833                         }
1834                         fpbuflen = DHKEY_SIZE;
1835                         if(!qd0_blind_id_sessionkey_public_id(CDATA->id, (char *) crypto->dhkey, &fpbuflen))
1836                         {
1837                                 CLEAR_CDATA;
1838                                 return Crypto_ServerError(data_out, len_out, "d0_blind_id_sessionkey_public_id failed", "Internal error");
1839                         }
1840                         if(CDATA->c >= 0)
1841                         {
1842                                 if(!qd0_blind_id_copy(CDATA->id, pubkeys[CDATA->c]))
1843                                 {
1844                                         CLEAR_CDATA;
1845                                         return Crypto_ServerError(data_out, len_out, "d0_blind_id_copy failed", "Internal error");
1846                                 }
1847                                 CDATA->next_step = 4;
1848                         }
1849                         else
1850                         {
1851                                 // session key is FINISHED (no server part is to be expected)! By this, all keys are set up
1852                                 crypto->authenticated = true;
1853                                 CDATA->next_step = 0;
1854                         }
1855                         data_out_p += *len_out;
1856                         *len_out = data_out_p - data_out;
1857                         return CRYPTO_DISCARD;
1858                 }
1859                 else if(!strcmp(cnt, "4"))
1860                 {
1861                         crypto = Crypto_ServerFindInstance(peeraddress, false);
1862                         if(!crypto)
1863                                 return CRYPTO_NOMATCH; // pre-challenge, rather be silent
1864                         if(id >= 0)
1865                                 if(CDATA->cdata_id != id)
1866                                         return Crypto_SoftServerError(data_out, len_out, va(vabuf, sizeof(vabuf), "Got d0pk\\id\\%d when expecting %d", id, CDATA->cdata_id));
1867                         if(CDATA->next_step != 4)
1868                                 return Crypto_SoftServerError(data_out, len_out, va(vabuf, sizeof(vabuf), "Got d0pk\\cnt\\%s when expecting %d", cnt, CDATA->next_step));
1869                         PutWithNul(&data_out_p, len_out, va(vabuf, sizeof(vabuf), "d0pk\\cnt\\5\\id\\%d", CDATA->cdata_id));
1870                         if(!qd0_blind_id_authenticate_with_private_id_challenge(CDATA->id, true, false, data_in, len_in, data_out_p, len_out, &status))
1871                         {
1872                                 CLEAR_CDATA;
1873                                 return Crypto_ServerError(data_out, len_out, "d0_blind_id_authenticate_with_private_id_challenge failed", "Internal error");
1874                         }
1875                         CDATA->next_step = 6;
1876                         data_out_p += *len_out;
1877                         *len_out = data_out_p - data_out;
1878                         return CRYPTO_DISCARD;
1879                 }
1880                 else if(!strcmp(cnt, "6"))
1881                 {
1882                         static char msgbuf[32];
1883                         size_t msgbuflen = sizeof(msgbuf);
1884                         size_t fpbuflen;
1885                         int i;
1886                         unsigned char dhkey[DHKEY_SIZE];
1887                         crypto = Crypto_ServerFindInstance(peeraddress, false);
1888                         if(!crypto)
1889                                 return CRYPTO_NOMATCH; // pre-challenge, rather be silent
1890                         if(id >= 0)
1891                                 if(CDATA->cdata_id != id)
1892                                         return Crypto_SoftServerError(data_out, len_out, va(vabuf, sizeof(vabuf), "Got d0pk\\id\\%d when expecting %d", id, CDATA->cdata_id));
1893                         if(CDATA->next_step != 6)
1894                                 return Crypto_SoftServerError(data_out, len_out, va(vabuf, sizeof(vabuf), "Got d0pk\\cnt\\%s when expecting %d", cnt, CDATA->next_step));
1895
1896                         if(!qd0_blind_id_authenticate_with_private_id_verify(CDATA->id, data_in, len_in, msgbuf, &msgbuflen, &status))
1897                         {
1898                                 CLEAR_CDATA;
1899                                 return Crypto_ServerError(data_out, len_out, "d0_blind_id_authenticate_with_private_id_verify failed (authentication error)", "Authentication error");
1900                         }
1901                         if(status)
1902                                 strlcpy(crypto->client_keyfp, pubkeys_fp64[CDATA->c], sizeof(crypto->client_keyfp));
1903                         else
1904                                 crypto->client_keyfp[0] = 0;
1905                         memset(crypto->client_idfp, 0, sizeof(crypto->client_idfp));
1906                         fpbuflen = FP64_SIZE;
1907                         if(!qd0_blind_id_fingerprint64_public_id(CDATA->id, crypto->client_idfp, &fpbuflen))
1908                         {
1909                                 CLEAR_CDATA;
1910                                 return Crypto_ServerError(data_out, len_out, "d0_blind_id_fingerprint64_public_id failed", "Internal error");
1911                         }
1912                         fpbuflen = DHKEY_SIZE;
1913                         if(!qd0_blind_id_sessionkey_public_id(CDATA->id, (char *) dhkey, &fpbuflen))
1914                         {
1915                                 CLEAR_CDATA;
1916                                 return Crypto_ServerError(data_out, len_out, "d0_blind_id_sessionkey_public_id failed", "Internal error");
1917                         }
1918                         // XOR the two DH keys together to make one
1919                         for(i = 0; i < DHKEY_SIZE; ++i)
1920                                 crypto->dhkey[i] ^= dhkey[i];
1921
1922                         // session key is FINISHED (no server part is to be expected)! By this, all keys are set up
1923                         crypto->authenticated = true;
1924                         CDATA->next_step = 0;
1925                         // send a challenge-less challenge
1926                         PutWithNul(&data_out_p, len_out, "challenge ");
1927                         *len_out = data_out_p - data_out;
1928                         --*len_out; // remove NUL terminator
1929                         return CRYPTO_MATCH;
1930                 }
1931                 return CRYPTO_NOMATCH; // pre-challenge, rather be silent
1932         }
1933         return CRYPTO_NOMATCH;
1934 }
1935
1936 int Crypto_ServerParsePacket(const char *data_in, size_t len_in, char *data_out, size_t *len_out, lhnetaddress_t *peeraddress)
1937 {
1938         int ret;
1939         double t = 0;
1940         static double complain_time = 0;
1941         const char *cnt;
1942         qboolean do_time = false;
1943         qboolean do_reject = false;
1944         char infostringvalue[MAX_INPUTLINE];
1945         if(crypto_servercpupercent.value > 0 || crypto_servercpumaxtime.value > 0)
1946                 if(len_in > 5 && !memcmp(data_in, "d0pk\\", 5))
1947                 {
1948                         do_time = true;
1949                         cnt = InfoString_GetValue(data_in + 4, "cnt", infostringvalue, sizeof(infostringvalue));
1950                         if(cnt)
1951                                 if(!strcmp(cnt, "0"))
1952                                         do_reject = true;
1953                 }
1954         if(do_time)
1955         {
1956                 // check if we may perform crypto...
1957                 if(crypto_servercpupercent.value > 0)
1958                 {
1959                         crypto_servercpu_accumulator += (realtime - crypto_servercpu_lastrealtime) * crypto_servercpupercent.value * 0.01;
1960                         if(crypto_servercpumaxtime.value)
1961                                 if(crypto_servercpu_accumulator > crypto_servercpumaxtime.value)
1962                                         crypto_servercpu_accumulator = crypto_servercpumaxtime.value;
1963                 }
1964                 else
1965                 {
1966                         if(crypto_servercpumaxtime.value > 0)
1967                                 if(realtime != crypto_servercpu_lastrealtime)
1968                                         crypto_servercpu_accumulator = crypto_servercpumaxtime.value;
1969                 }
1970                 crypto_servercpu_lastrealtime = realtime;
1971                 if(do_reject && crypto_servercpu_accumulator < 0)
1972                 {
1973                         if(realtime > complain_time + 5)
1974                                 Con_Printf("crypto: cannot perform requested crypto operations; denial service attack or crypto_servercpupercent/crypto_servercpumaxtime are too low\n");
1975                         *len_out = 0;
1976                         return CRYPTO_DISCARD;
1977                 }
1978                 t = Sys_DirtyTime();
1979         }
1980         ret = Crypto_ServerParsePacket_Internal(data_in, len_in, data_out, len_out, peeraddress);
1981         if(do_time)
1982         {
1983                 t = Sys_DirtyTime() - t;if (t < 0.0) t = 0.0; // dirtytime can step backwards
1984                 if(crypto_servercpudebug.integer)
1985                         Con_Printf("crypto: accumulator was %.1f ms, used %.1f ms for crypto, ", crypto_servercpu_accumulator * 1000, t * 1000);
1986                 crypto_servercpu_accumulator -= t;
1987                 if(crypto_servercpudebug.integer)
1988                         Con_Printf("is %.1f ms\n", crypto_servercpu_accumulator * 1000);
1989         }
1990         return ret;
1991 }
1992
1993 static int Crypto_ClientError(char *data_out, size_t *len_out, const char *msg)
1994 {
1995         dpsnprintf(data_out, *len_out, "reject %s", msg);
1996         *len_out = strlen(data_out);
1997         return CRYPTO_REPLACE;
1998 }
1999
2000 static int Crypto_SoftClientError(char *data_out, size_t *len_out, const char *msg)
2001 {
2002         *len_out = 0;
2003         Con_Printf("%s\n", msg);
2004         return CRYPTO_DISCARD;
2005 }
2006
2007 int Crypto_ClientParsePacket(const char *data_in, size_t len_in, char *data_out, size_t *len_out, lhnetaddress_t *peeraddress)
2008 {
2009         crypto_t *crypto = &cls.crypto;
2010         const char *string = data_in;
2011         const char *s;
2012         D0_BOOL aes;
2013         char *data_out_p = data_out;
2014         D0_BOOL status;
2015         char infostringvalue[MAX_INPUTLINE];
2016         char vabuf[1024];
2017
2018         if(!d0_blind_id_dll)
2019                 return CRYPTO_NOMATCH; // no support
2020
2021         // if "challenge": verify challenge, and discard message, send next crypto protocol message instead
2022         // otherwise, just handle actual protocol messages
2023
2024         if (len_in == 6 && !memcmp(string, "accept", 6) && cls.connect_trying && d0_rijndael_dll)
2025         {
2026                 int wantserverid = -1;
2027                 Crypto_RetrieveHostKey(&cls.connect_address, &wantserverid, NULL, 0, NULL, 0, NULL);
2028                 if(!crypto || !crypto->authenticated)
2029                 {
2030                         if(wantserverid >= 0)
2031                                 return Crypto_ClientError(data_out, len_out, "Server tried an unauthenticated connection even though a host key is present");
2032                         if(crypto_aeslevel.integer >= 3)
2033                                 return Crypto_ClientError(data_out, len_out, "This server requires encryption to be not required (crypto_aeslevel <= 2)");
2034                 }
2035                 return CRYPTO_NOMATCH;
2036         }
2037         else if (len_in >= 1 && string[0] == 'j' && cls.connect_trying && d0_rijndael_dll && crypto_aeslevel.integer >= 3)
2038         {
2039                 int wantserverid = -1;
2040                 Crypto_RetrieveHostKey(&cls.connect_address, &wantserverid, NULL, 0, NULL, 0, NULL);
2041                 if(!crypto || !crypto->authenticated)
2042                 {
2043                         if(wantserverid >= 0)
2044                                 return Crypto_ClientError(data_out, len_out, "Server tried an unauthenticated connection even though a host key is present");
2045                         if(crypto_aeslevel.integer >= 3)
2046                                 return Crypto_ClientError(data_out, len_out, "This server requires encryption to be not required (crypto_aeslevel <= 2)");
2047                 }
2048                 return CRYPTO_NOMATCH;
2049         }
2050         else if (len_in >= 13 && !memcmp(string, "infoResponse\x0A", 13))
2051         {
2052                 s = InfoString_GetValue(string + 13, "d0_blind_id", infostringvalue, sizeof(infostringvalue));
2053                 if(s)
2054                         Crypto_StoreHostKey(peeraddress, s, true);
2055                 return CRYPTO_NOMATCH;
2056         }
2057         else if (len_in >= 15 && !memcmp(string, "statusResponse\x0A", 15))
2058         {
2059                 char save = 0;
2060                 const char *p;
2061                 p = strchr(string + 15, '\n');
2062                 if(p)
2063                 {
2064                         save = *p;
2065                         * (char *) p = 0; // cut off the string there
2066                 }
2067                 s = InfoString_GetValue(string + 15, "d0_blind_id", infostringvalue, sizeof(infostringvalue));
2068                 if(s)
2069                         Crypto_StoreHostKey(peeraddress, s, true);
2070                 if(p)
2071                 {
2072                         * (char *) p = save;
2073                         // invoking those nasal demons again (do not run this on the DS9k)
2074                 }
2075                 return CRYPTO_NOMATCH;
2076         }
2077         else if(len_in > 10 && !memcmp(string, "challenge ", 10) && cls.connect_trying)
2078         {
2079                 const char *vlen_blind_id_ptr = NULL;
2080                 size_t len_blind_id_ptr = 0;
2081                 unsigned long k, v;
2082                 const char *challenge = data_in + 10;
2083                 const char *p;
2084                 int i;
2085                 int clientid = -1, serverid = -1, wantserverid = -1;
2086                 qboolean server_can_auth = true;
2087                 char wantserver_idfp[FP64_SIZE+1];
2088                 int wantserver_aeslevel;
2089
2090                 // if we have a stored host key for the server, assume serverid to already be selected!
2091                 // (the loop will refuse to overwrite this one then)
2092                 wantserver_idfp[0] = 0;
2093                 Crypto_RetrieveHostKey(&cls.connect_address, &wantserverid, NULL, 0, wantserver_idfp, sizeof(wantserver_idfp), &wantserver_aeslevel);
2094                 // requirement: wantserver_idfp is a full ID if wantserverid set
2095
2096                 // if we leave, we have to consider the connection
2097                 // unauthenticated; NOTE: this may be faked by a clever
2098                 // attacker to force an unauthenticated connection; so we have
2099                 // a safeguard check in place when encryption is required too
2100                 // in place, or when authentication is required by the server
2101                 crypto->authenticated = false;
2102
2103                 GetUntilNul(&data_in, &len_in);
2104                 if(!data_in)
2105                         return (wantserverid >= 0) ? Crypto_ClientError(data_out, len_out, "Server tried an unauthenticated connection even though a host key is present") :
2106                                 (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) :
2107                                 CRYPTO_NOMATCH;
2108
2109                 // FTEQW extension protocol
2110                 while(len_in >= 8)
2111                 {
2112                         k = Crypto_LittleLong(data_in);
2113                         v = Crypto_LittleLong(data_in + 4);
2114                         data_in += 8;
2115                         len_in -= 8;
2116                         switch(k)
2117                         {
2118                                 case PROTOCOL_VLEN:
2119                                         if(len_in >= 4 + v)
2120                                         {
2121                                                 k = Crypto_LittleLong(data_in);
2122                                                 data_in += 4;
2123                                                 len_in -= 4;
2124                                                 switch(k)
2125                                                 {
2126                                                         case PROTOCOL_D0_BLIND_ID:
2127                                                                 vlen_blind_id_ptr = data_in;
2128                                                                 len_blind_id_ptr = v;
2129                                                                 break;
2130                                                 }
2131                                                 data_in += v;
2132                                                 len_in -= v;
2133                                         }
2134                                         break;
2135                                 default:
2136                                         break;
2137                         }
2138                 }
2139
2140                 if(!vlen_blind_id_ptr)
2141                         return (wantserverid >= 0) ? Crypto_ClientError(data_out, len_out, "Server tried an unauthenticated connection even though authentication is required") :
2142                                 (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) :
2143                                 CRYPTO_NOMATCH;
2144
2145                 data_in = vlen_blind_id_ptr;
2146                 len_in = len_blind_id_ptr;
2147
2148                 // parse fingerprints
2149                 //   once we found a fingerprint we can auth to (ANY), select it as clientfp
2150                 //   once we found a fingerprint in the first list that we know, select it as serverfp
2151
2152                 for(;;)
2153                 {
2154                         p = GetUntilNul(&data_in, &len_in);
2155                         if(!p)
2156                                 break;
2157                         if(!*p)
2158                         {
2159                                 if(!server_can_auth)
2160                                         break; // other protocol message may follow
2161                                 server_can_auth = false;
2162                                 if(clientid >= 0)
2163                                         break;
2164                                 continue;
2165                         }
2166                         for(i = 0; i < MAX_PUBKEYS; ++i)
2167                         {
2168                                 if(pubkeys[i])
2169                                 if(!strcmp(p, pubkeys_fp64[i]))
2170                                 {
2171                                         if(pubkeys_havepriv[i])
2172                                                 if(clientid < 0)
2173                                                         clientid = i;
2174                                         if(server_can_auth)
2175                                                 if(serverid < 0)
2176                                                         if(wantserverid < 0 || i == wantserverid)
2177                                                                 serverid = i;
2178                                 }
2179                         }
2180                         if(clientid >= 0 && serverid >= 0)
2181                                 break;
2182                 }
2183
2184                 // if stored host key is not found:
2185                 if(wantserverid >= 0 && serverid < 0)
2186                         return Crypto_ClientError(data_out, len_out, "Server CA does not match stored host key, refusing to connect");
2187
2188                 if(serverid >= 0 || clientid >= 0)
2189                 {
2190                         // TODO at this point, fill clientside crypto struct!
2191                         MAKE_CDATA;
2192                         CDATA->cdata_id = ++cdata_id;
2193                         CDATA->s = serverid;
2194                         CDATA->c = clientid;
2195                         memset(crypto->dhkey, 0, sizeof(crypto->dhkey));
2196                         strlcpy(CDATA->challenge, challenge, sizeof(CDATA->challenge));
2197                         crypto->client_keyfp[0] = 0;
2198                         crypto->client_idfp[0] = 0;
2199                         crypto->server_keyfp[0] = 0;
2200                         crypto->server_idfp[0] = 0;
2201                         memcpy(CDATA->wantserver_idfp, wantserver_idfp, sizeof(crypto->server_idfp));
2202
2203                         if(CDATA->wantserver_idfp[0]) // if we know a host key, honor its encryption setting
2204                         switch(bound(0, d0_rijndael_dll ? crypto_aeslevel.integer : 0, 3))
2205                         {
2206                                 default: // dummy, never happens, but to make gcc happy...
2207                                 case 0:
2208                                         if(wantserver_aeslevel >= 3)
2209                                                 return Crypto_ServerError(data_out, len_out, "This server requires encryption to be not required (crypto_aeslevel <= 2)", NULL);
2210                                         CDATA->wantserver_aes = false;
2211                                         break;
2212                                 case 1:
2213                                         CDATA->wantserver_aes = (wantserver_aeslevel >= 2);
2214                                         break;
2215                                 case 2:
2216                                         CDATA->wantserver_aes = (wantserver_aeslevel >= 1);
2217                                         break;
2218                                 case 3:
2219                                         if(wantserver_aeslevel <= 0)
2220                                                 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);
2221                                         CDATA->wantserver_aes = true;
2222                                         break;
2223                         }
2224
2225                         // build outgoing message
2226                         // append regular stuff
2227                         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));
2228                         PutWithNul(&data_out_p, len_out, serverid >= 0 ? pubkeys_fp64[serverid] : "");
2229                         PutWithNul(&data_out_p, len_out, clientid >= 0 ? pubkeys_fp64[clientid] : "");
2230
2231                         if(clientid >= 0)
2232                         {
2233                                 // I am the client, and my key is ok... so let's set client_keyfp and client_idfp
2234                                 strlcpy(crypto->client_keyfp, pubkeys_fp64[CDATA->c], sizeof(crypto->client_keyfp));
2235                                 strlcpy(crypto->client_idfp, pubkeys_priv_fp64[CDATA->c], sizeof(crypto->client_idfp));
2236                         }
2237
2238                         if(serverid >= 0)
2239                         {
2240                                 if(!CDATA->id)
2241                                         CDATA->id = qd0_blind_id_new();
2242                                 if(!CDATA->id)
2243                                 {
2244                                         CLEAR_CDATA;
2245                                         return Crypto_ClientError(data_out, len_out, "d0_blind_id_new failed");
2246                                 }
2247                                 if(!qd0_blind_id_copy(CDATA->id, pubkeys[CDATA->s]))
2248                                 {
2249                                         CLEAR_CDATA;
2250                                         return Crypto_ClientError(data_out, len_out, "d0_blind_id_copy failed");
2251                                 }
2252                                 CDATA->next_step = 1;
2253                                 *len_out = data_out_p - data_out;
2254                         }
2255                         else if(clientid >= 0)
2256                         {
2257                                 // skip over server auth, perform client auth only
2258                                 if(!CDATA->id)
2259                                         CDATA->id = qd0_blind_id_new();
2260                                 if(!CDATA->id)
2261                                 {
2262                                         CLEAR_CDATA;
2263                                         return Crypto_ClientError(data_out, len_out, "d0_blind_id_new failed");
2264                                 }
2265                                 if(!qd0_blind_id_copy(CDATA->id, pubkeys[CDATA->c]))
2266                                 {
2267                                         CLEAR_CDATA;
2268                                         return Crypto_ClientError(data_out, len_out, "d0_blind_id_copy failed");
2269                                 }
2270                                 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
2271                                 {
2272                                         CLEAR_CDATA;
2273                                         return Crypto_ClientError(data_out, len_out, "d0_blind_id_authenticate_with_private_id_start failed");
2274                                 }
2275                                 CDATA->next_step = 5;
2276                                 data_out_p += *len_out;
2277                                 *len_out = data_out_p - data_out;
2278                         }
2279                         else
2280                                 *len_out = data_out_p - data_out;
2281
2282                         return CRYPTO_DISCARD;
2283                 }
2284                 else
2285                 {
2286                         if(wantserver_idfp[0]) // if we know a host key, honor its encryption setting
2287                         if(wantserver_aeslevel >= 3)
2288                                 return Crypto_ClientError(data_out, len_out, "Server insists on encryption, but neither can authenticate to the other");
2289                         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) :
2290                                 CRYPTO_NOMATCH;
2291                 }
2292         }
2293         else if(len_in > 5 && !memcmp(string, "d0pk\\", 5) && cls.connect_trying)
2294         {
2295                 const char *cnt;
2296                 int id;
2297                 cnt = InfoString_GetValue(string + 4, "id", infostringvalue, sizeof(infostringvalue));
2298                 id = (cnt ? atoi(cnt) : -1);
2299                 cnt = InfoString_GetValue(string + 4, "cnt", infostringvalue, sizeof(infostringvalue));
2300                 if(!cnt)
2301                         return Crypto_ClientError(data_out, len_out, "d0pk\\ message without cnt");
2302                 GetUntilNul(&data_in, &len_in);
2303                 if(!data_in)
2304                         return Crypto_ClientError(data_out, len_out, "d0pk\\ message without attachment");
2305
2306                 if(!strcmp(cnt, "1"))
2307                 {
2308                         if(id >= 0)
2309                                 if(CDATA->cdata_id != id)
2310                                         return Crypto_SoftServerError(data_out, len_out, va(vabuf, sizeof(vabuf), "Got d0pk\\id\\%d when expecting %d", id, CDATA->cdata_id));
2311                         if(CDATA->next_step != 1)
2312                                 return Crypto_SoftClientError(data_out, len_out, va(vabuf, sizeof(vabuf), "Got d0pk\\cnt\\%s when expecting %d", cnt, CDATA->next_step));
2313
2314                         cls.connect_nextsendtime = max(cls.connect_nextsendtime, realtime + 1); // prevent "hammering"
2315
2316                         if((s = InfoString_GetValue(string + 4, "aes", infostringvalue, sizeof(infostringvalue))))
2317                                 aes = atoi(s);
2318                         else
2319                                 aes = false;
2320                         // we CANNOT toggle the AES status any more!
2321                         // as the server already decided
2322                         if(CDATA->wantserver_idfp[0]) // if we know a host key, honor its encryption setting
2323                         if(!aes && CDATA->wantserver_aes)
2324                         {
2325                                 CLEAR_CDATA;
2326                                 return Crypto_ClientError(data_out, len_out, "Stored host key requires encryption, but server did not enable encryption");
2327                         }
2328                         if(aes && (!d0_rijndael_dll || crypto_aeslevel.integer <= 0))
2329                         {
2330                                 CLEAR_CDATA;
2331                                 return Crypto_ClientError(data_out, len_out, "Server insists on encryption too hard");
2332                         }
2333                         if(!aes && (d0_rijndael_dll && crypto_aeslevel.integer >= 3))
2334                         {
2335                                 CLEAR_CDATA;
2336                                 return Crypto_ClientError(data_out, len_out, "Server insists on plaintext too hard");
2337                         }
2338                         crypto->use_aes = aes != 0;
2339
2340                         PutWithNul(&data_out_p, len_out, va(vabuf, sizeof(vabuf), "d0pk\\cnt\\2\\id\\%d", CDATA->cdata_id));
2341                         if(!qd0_blind_id_authenticate_with_private_id_challenge(CDATA->id, true, false, data_in, len_in, data_out_p, len_out, &status))
2342                         {
2343                                 CLEAR_CDATA;
2344                                 return Crypto_ClientError(data_out, len_out, "d0_blind_id_authenticate_with_private_id_challenge failed");
2345                         }
2346                         CDATA->next_step = 3;
2347                         data_out_p += *len_out;
2348                         *len_out = data_out_p - data_out;
2349                         return CRYPTO_DISCARD;
2350                 }
2351                 else if(!strcmp(cnt, "3"))
2352                 {
2353                         static char msgbuf[32];
2354                         size_t msgbuflen = sizeof(msgbuf);
2355                         size_t fpbuflen;
2356
2357                         if(id >= 0)
2358                                 if(CDATA->cdata_id != id)
2359                                         return Crypto_SoftServerError(data_out, len_out, va(vabuf, sizeof(vabuf), "Got d0pk\\id\\%d when expecting %d", id, CDATA->cdata_id));
2360                         if(CDATA->next_step != 3)
2361                                 return Crypto_SoftClientError(data_out, len_out, va(vabuf, sizeof(vabuf), "Got d0pk\\cnt\\%s when expecting %d", cnt, CDATA->next_step));
2362
2363                         cls.connect_nextsendtime = max(cls.connect_nextsendtime, realtime + 1); // prevent "hammering"
2364
2365                         if(!qd0_blind_id_authenticate_with_private_id_verify(CDATA->id, data_in, len_in, msgbuf, &msgbuflen, &status))
2366                         {
2367                                 CLEAR_CDATA;
2368                                 return Crypto_ClientError(data_out, len_out, "d0_blind_id_authenticate_with_private_id_verify failed (server authentication error)");
2369                         }
2370                         if(status)
2371                                 strlcpy(crypto->server_keyfp, pubkeys_fp64[CDATA->s], sizeof(crypto->server_keyfp));
2372                         else
2373                                 crypto->server_keyfp[0] = 0;
2374                         memset(crypto->server_idfp, 0, sizeof(crypto->server_idfp));
2375                         fpbuflen = FP64_SIZE;
2376                         if(!qd0_blind_id_fingerprint64_public_id(CDATA->id, crypto->server_idfp, &fpbuflen))
2377                         {
2378                                 CLEAR_CDATA;
2379                                 return Crypto_ClientError(data_out, len_out, "d0_blind_id_fingerprint64_public_id failed");
2380                         }
2381                         if(CDATA->wantserver_idfp[0])
2382                         if(memcmp(CDATA->wantserver_idfp, crypto->server_idfp, sizeof(crypto->server_idfp)))
2383                         {
2384                                 CLEAR_CDATA;
2385                                 return Crypto_ClientError(data_out, len_out, "Server ID does not match stored host key, refusing to connect");
2386                         }
2387                         fpbuflen = DHKEY_SIZE;
2388                         if(!qd0_blind_id_sessionkey_public_id(CDATA->id, (char *) crypto->dhkey, &fpbuflen))
2389                         {
2390                                 CLEAR_CDATA;
2391                                 return Crypto_ClientError(data_out, len_out, "d0_blind_id_sessionkey_public_id failed");
2392                         }
2393
2394                         // cache the server key
2395                         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);
2396
2397                         if(CDATA->c >= 0)
2398                         {
2399                                 // client will auth next
2400                                 PutWithNul(&data_out_p, len_out, va(vabuf, sizeof(vabuf), "d0pk\\cnt\\4\\id\\%d", CDATA->cdata_id));
2401                                 if(!qd0_blind_id_copy(CDATA->id, pubkeys[CDATA->c]))
2402                                 {
2403                                         CLEAR_CDATA;
2404                                         return Crypto_ClientError(data_out, len_out, "d0_blind_id_copy failed");
2405                                 }
2406                                 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
2407                                 {
2408                                         CLEAR_CDATA;
2409                                         return Crypto_ClientError(data_out, len_out, "d0_blind_id_authenticate_with_private_id_start failed");
2410                                 }
2411                                 CDATA->next_step = 5;
2412                                 data_out_p += *len_out;
2413                                 *len_out = data_out_p - data_out;
2414                                 return CRYPTO_DISCARD;
2415                         }
2416                         else
2417                         {
2418                                 // session key is FINISHED (no server part is to be expected)! By this, all keys are set up
2419                                 crypto->authenticated = true;
2420                                 CDATA->next_step = 0;
2421                                 // assume we got the empty challenge to finish the protocol
2422                                 PutWithNul(&data_out_p, len_out, "challenge ");
2423                                 *len_out = data_out_p - data_out;
2424                                 --*len_out; // remove NUL terminator
2425                                 return CRYPTO_REPLACE;
2426                         }
2427                 }
2428                 else if(!strcmp(cnt, "5"))
2429                 {
2430                         size_t fpbuflen;
2431                         unsigned char dhkey[DHKEY_SIZE];
2432                         int i;
2433
2434                         if(id >= 0)
2435                                 if(CDATA->cdata_id != id)
2436                                         return Crypto_SoftServerError(data_out, len_out, va(vabuf, sizeof(vabuf), "Got d0pk\\id\\%d when expecting %d", id, CDATA->cdata_id));
2437                         if(CDATA->next_step != 5)
2438                                 return Crypto_SoftClientError(data_out, len_out, va(vabuf, sizeof(vabuf), "Got d0pk\\cnt\\%s when expecting %d", cnt, CDATA->next_step));
2439
2440                         cls.connect_nextsendtime = max(cls.connect_nextsendtime, realtime + 1); // prevent "hammering"
2441
2442                         if(CDATA->s < 0) // only if server didn't auth
2443                         {
2444                                 if((s = InfoString_GetValue(string + 4, "aes", infostringvalue, sizeof(infostringvalue))))
2445                                         aes = atoi(s);
2446                                 else
2447                                         aes = false;
2448                                 if(CDATA->wantserver_idfp[0]) // if we know a host key, honor its encryption setting
2449                                 if(!aes && CDATA->wantserver_aes)
2450                                 {
2451                                         CLEAR_CDATA;
2452                                         return Crypto_ClientError(data_out, len_out, "Stored host key requires encryption, but server did not enable encryption");
2453                                 }
2454                                 if(aes && (!d0_rijndael_dll || crypto_aeslevel.integer <= 0))
2455                                 {
2456                                         CLEAR_CDATA;
2457                                         return Crypto_ClientError(data_out, len_out, "Server insists on encryption too hard");
2458                                 }
2459                                 if(!aes && (d0_rijndael_dll && crypto_aeslevel.integer >= 3))
2460                                 {
2461                                         CLEAR_CDATA;
2462                                         return Crypto_ClientError(data_out, len_out, "Server insists on plaintext too hard");
2463                                 }
2464                                 crypto->use_aes = aes != 0;
2465                         }
2466
2467                         PutWithNul(&data_out_p, len_out, va(vabuf, sizeof(vabuf), "d0pk\\cnt\\6\\id\\%d", CDATA->cdata_id));
2468                         if(!qd0_blind_id_authenticate_with_private_id_response(CDATA->id, data_in, len_in, data_out_p, len_out))
2469                         {
2470                                 CLEAR_CDATA;
2471                                 return Crypto_ClientError(data_out, len_out, "d0_blind_id_authenticate_with_private_id_response failed");
2472                         }
2473                         fpbuflen = DHKEY_SIZE;
2474                         if(!qd0_blind_id_sessionkey_public_id(CDATA->id, (char *) dhkey, &fpbuflen))
2475                         {
2476                                 CLEAR_CDATA;
2477                                 return Crypto_ClientError(data_out, len_out, "d0_blind_id_sessionkey_public_id failed");
2478                         }
2479                         // XOR the two DH keys together to make one
2480                         for(i = 0; i < DHKEY_SIZE; ++i)
2481                                 crypto->dhkey[i] ^= dhkey[i];
2482                         // session key is FINISHED! By this, all keys are set up
2483                         crypto->authenticated = true;
2484                         CDATA->next_step = 0;
2485                         data_out_p += *len_out;
2486                         *len_out = data_out_p - data_out;
2487                         return CRYPTO_DISCARD;
2488                 }
2489                 return Crypto_SoftClientError(data_out, len_out, "Got unknown d0_blind_id message from server");
2490         }
2491
2492         return CRYPTO_NOMATCH;
2493 }
2494
2495 size_t Crypto_SignData(const void *data, size_t datasize, int keyid, void *signed_data, size_t signed_size)
2496 {
2497         if(keyid < 0 || keyid >= MAX_PUBKEYS)
2498                 return 0;
2499         if(!pubkeys_havepriv[keyid])
2500                 return 0;
2501         if(qd0_blind_id_sign_with_private_id_sign(pubkeys[keyid], true, false, (const char *)data, datasize, (char *)signed_data, &signed_size))
2502                 return signed_size;
2503         return 0;
2504 }
2505
2506 size_t Crypto_SignDataDetached(const void *data, size_t datasize, int keyid, void *signed_data, size_t signed_size)
2507 {
2508         if(keyid < 0 || keyid >= MAX_PUBKEYS)
2509                 return 0;
2510         if(!pubkeys_havepriv[keyid])
2511                 return 0;
2512         if(qd0_blind_id_sign_with_private_id_sign_detached(pubkeys[keyid], true, false, (const char *)data, datasize, (char *)signed_data, &signed_size))
2513                 return signed_size;
2514         return 0;
2515 }