X-Git-Url: https://git.xonotic.org/?a=blobdiff_plain;f=d0_blind_id.c;h=f33084cb912d77fe467da0dd7c9e979ae0c9d3b1;hb=f6aeffa5a621516e73fa72d2471c2a77d8a831a2;hp=3abfb9da74d1b24406fc06acea886fbb3f7ad8d7;hpb=09adb6717861941b70ce52996a6159ffe23c5d0c;p=xonotic%2Fd0_blind_id.git diff --git a/d0_blind_id.c b/d0_blind_id.c index 3abfb9d..f33084c 100644 --- a/d0_blind_id.c +++ b/d0_blind_id.c @@ -40,11 +40,14 @@ #include "d0_bignum.h" #include "sha2.h" +// old "positive" protocol, uses one extra mod_inv in verify stages +// #define D0_BLIND_ID_POSITIVE_PROTOCOL + // our SHA is SHA-256 #define SHA_DIGESTSIZE 32 const char *sha(const unsigned char *in, size_t len) { - static char h[32]; + static __thread char h[32]; d0_blind_id_util_sha256(h, (const char *) in, len); return h; } @@ -94,18 +97,32 @@ struct d0_blind_id_s size_t msglen; // message length }; +//#define CHECKDEBUG +#ifdef CHECKDEBUG +#define CHECK(x) do { if(!(x)) { fprintf(stderr, "CHECK FAILED (%s:%d): %s\n", __FILE__, __LINE__, #x); goto fail; } } while(0) +#define CHECK_ASSIGN(var, value) do { d0_bignum_t *val; val = value; if(!val) { fprintf(stderr, "CHECK FAILED (%s:%d): %s\n", __FILE__, __LINE__, #value); goto fail; } var = val; } while(0) +#else #define CHECK(x) do { if(!(x)) goto fail; } while(0) #define CHECK_ASSIGN(var, value) do { d0_bignum_t *val; val = value; if(!val) goto fail; var = val; } while(0) -#define MPCHECK(x) do { if(!failed) if(!(x)) failed = 1; } while(0) -#define MPCHECK_ASSIGN(var, value) do { if(!failed) { d0_bignum_t *val; val = value; if(val) var = val; else failed = 1; } } while(0) +#endif #define USING(x) if(!(ctx->x)) return 0 #define REPLACING(x) -static d0_bignum_t *zero, *one, *four, *temp0, *temp1, *temp2, *temp3, *temp4; +// safe to use +static d0_bignum_t *zero, *one, *four; + +static d0_bignum_t *temp0, *temp1, *temp2, *temp3, *temp4; +static void *tempmutex = NULL; // hold this mutex when using temp0 to temp4 +#define USINGTEMPS() int locked = 0 +#define LOCKTEMPS() do { if(!locked) d0_lockmutex(tempmutex); locked = 1; } while(0) +#define UNLOCKTEMPS() do { if(locked) d0_unlockmutex(tempmutex); locked = 0; } while(0); D0_WARN_UNUSED_RESULT D0_BOOL d0_blind_id_INITIALIZE(void) { + USINGTEMPS(); + tempmutex = d0_createmutex(); + LOCKTEMPS(); CHECK(d0_bignum_INITIALIZE()); CHECK_ASSIGN(zero, d0_bignum_int(zero, 0)); CHECK_ASSIGN(one, d0_bignum_int(one, 1)); @@ -115,13 +132,17 @@ D0_WARN_UNUSED_RESULT D0_BOOL d0_blind_id_INITIALIZE(void) CHECK_ASSIGN(temp2, d0_bignum_int(temp2, 0)); CHECK_ASSIGN(temp3, d0_bignum_int(temp3, 0)); CHECK_ASSIGN(temp4, d0_bignum_int(temp4, 0)); + UNLOCKTEMPS(); return 1; fail: + UNLOCKTEMPS(); return 0; } void d0_blind_id_SHUTDOWN(void) { + USINGTEMPS(); + LOCKTEMPS(); d0_bignum_free(zero); d0_bignum_free(one); d0_bignum_free(four); @@ -131,10 +152,13 @@ void d0_blind_id_SHUTDOWN(void) d0_bignum_free(temp3); d0_bignum_free(temp4); d0_bignum_SHUTDOWN(); + UNLOCKTEMPS(); + d0_destroymutex(tempmutex); + tempmutex = NULL; } // (G-1)/2 -d0_bignum_t *d0_dl_get_order(d0_bignum_t *o, const d0_bignum_t *G) +static d0_bignum_t *d0_dl_get_order(d0_bignum_t *o, const d0_bignum_t *G) { CHECK_ASSIGN(o, d0_bignum_sub(o, G, one)); CHECK(d0_bignum_shl(o, o, -1)); // order o = (G-1)/2 @@ -152,13 +176,15 @@ fail: return NULL; } -D0_BOOL d0_dl_generate_key(size_t size, d0_bignum_t *G) +// temps must NOT be locked when calling this +static D0_BOOL d0_dl_generate_key(size_t size, d0_bignum_t *G) { - // using: temp0 + USINGTEMPS(); // using: temp0 if(size < 16) size = 16; for(;;) { + LOCKTEMPS(); CHECK(d0_bignum_rand_bit_exact(temp0, size-1)); if(d0_bignum_isprime(temp0, 0) == 0) continue; @@ -167,16 +193,19 @@ D0_BOOL d0_dl_generate_key(size_t size, d0_bignum_t *G) continue; if(d0_bignum_isprime(temp0, 10) == 0) // finish the previous test continue; + UNLOCKTEMPS(); break; } return 1; fail: + UNLOCKTEMPS(); return 0; } -D0_BOOL d0_rsa_generate_key(size_t size, const d0_bignum_t *challenge, d0_bignum_t *d, d0_bignum_t *n) +// temps must NOT be locked when calling this +static D0_BOOL d0_rsa_generate_key(size_t size, d0_blind_id_t *ctx) { - // uses temp0 to temp4 + USINGTEMPS(); // uses temp1 to temp4 int fail = 0; int gcdfail = 0; int pb = (size + 1)/2; @@ -185,54 +214,76 @@ D0_BOOL d0_rsa_generate_key(size_t size, const d0_bignum_t *challenge, d0_bignum pb = 8; if(qb < 8) qb = 8; + + // we use ctx->rsa_d for the first result so that we can unlock temps later for (;;) { - CHECK(d0_bignum_rand_bit_exact(temp0, pb)); - if(d0_bignum_isprime(temp0, 10) == 0) + LOCKTEMPS(); + CHECK(d0_bignum_rand_bit_exact(ctx->rsa_d, pb)); + if(d0_bignum_isprime(ctx->rsa_d, 10) == 0) + { + UNLOCKTEMPS(); continue; - CHECK(d0_bignum_sub(temp2, temp0, one)); - CHECK(d0_bignum_gcd(temp4, NULL, NULL, temp2, challenge)); + } + CHECK(d0_bignum_sub(temp2, ctx->rsa_d, one)); + CHECK(d0_bignum_gcd(temp4, NULL, NULL, temp2, ctx->rsa_e)); if(!d0_bignum_cmp(temp4, one)) break; if(++gcdfail == 3) - return 0; + goto fail; ++gcdfail; } + UNLOCKTEMPS(); + gcdfail = 0; for (;;) { + LOCKTEMPS(); CHECK(d0_bignum_rand_bit_exact(temp1, qb)); - if(!d0_bignum_cmp(temp1, temp0)) + if(!d0_bignum_cmp(temp1, ctx->rsa_d)) { + UNLOCKTEMPS(); if(++fail == 3) - return 0; + goto fail; + continue; } fail = 0; if(d0_bignum_isprime(temp1, 10) == 0) + { + UNLOCKTEMPS(); continue; + } CHECK(d0_bignum_sub(temp3, temp1, one)); - CHECK(d0_bignum_gcd(temp4, NULL, NULL, temp3, challenge)); + CHECK(d0_bignum_gcd(temp4, NULL, NULL, temp3, ctx->rsa_e)); if(!d0_bignum_cmp(temp4, one)) + { + // we do NOT unlock, as we still need temp1 and temp3 break; + } + UNLOCKTEMPS(); if(++gcdfail == 3) - return 0; + goto fail; ++gcdfail; } - // n = temp0*temp1 - CHECK(d0_bignum_mul(n, temp0, temp1)); + // ctx->rsa_n = ctx->rsa_d*temp1 + CHECK(d0_bignum_mul(ctx->rsa_n, ctx->rsa_d, temp1)); - // d = challenge^-1 mod (temp0-1)(temp1-1) + // ctx->rsa_d = ctx->rsa_e^-1 mod (ctx->rsa_d-1)(temp1-1) + CHECK(d0_bignum_sub(temp2, ctx->rsa_d, one)); // we can't reuse the value from above because temps were unlocked CHECK(d0_bignum_mul(temp0, temp2, temp3)); - CHECK(d0_bignum_mod_inv(d, challenge, temp0)); + CHECK(d0_bignum_mod_inv(ctx->rsa_d, ctx->rsa_e, temp0)); + UNLOCKTEMPS(); return 1; fail: + UNLOCKTEMPS(); return 0; } -D0_BOOL d0_rsa_generate_key_fastreject(size_t size, d0_fastreject_function reject, d0_blind_id_t *ctx, void *pass) +// temps must NOT be locked when calling this +static D0_BOOL d0_rsa_generate_key_fastreject(size_t size, d0_fastreject_function reject, d0_blind_id_t *ctx, void *pass) { - // uses temp0 to temp4 + USINGTEMPS(); // uses temp1 to temp4 int fail = 0; int gcdfail = 0; int pb = (size + 1)/2; @@ -241,12 +292,18 @@ D0_BOOL d0_rsa_generate_key_fastreject(size_t size, d0_fastreject_function rejec pb = 8; if(qb < 8) qb = 8; + + // we use ctx->rsa_d for the first result so that we can unlock temps later for (;;) { - CHECK(d0_bignum_rand_bit_exact(temp0, pb)); - if(d0_bignum_isprime(temp0, 10) == 0) + LOCKTEMPS(); + CHECK(d0_bignum_rand_bit_exact(ctx->rsa_d, pb)); + if(d0_bignum_isprime(ctx->rsa_d, 10) == 0) + { + UNLOCKTEMPS(); continue; - CHECK(d0_bignum_sub(temp2, temp0, one)); + } + CHECK(d0_bignum_sub(temp2, ctx->rsa_d, one)); CHECK(d0_bignum_gcd(temp4, NULL, NULL, temp2, ctx->rsa_e)); if(!d0_bignum_cmp(temp4, one)) break; @@ -254,38 +311,56 @@ D0_BOOL d0_rsa_generate_key_fastreject(size_t size, d0_fastreject_function rejec return 0; ++gcdfail; } + UNLOCKTEMPS(); + gcdfail = 0; for (;;) { + LOCKTEMPS(); CHECK(d0_bignum_rand_bit_exact(temp1, qb)); - if(!d0_bignum_cmp(temp1, temp0)) + if(!d0_bignum_cmp(temp1, ctx->rsa_d)) { + UNLOCKTEMPS(); if(++fail == 3) return 0; + continue; } fail = 0; - // n = temp0*temp1 - CHECK(d0_bignum_mul(ctx->rsa_n, temp0, temp1)); + // n = ctx->rsa_d*temp1 + CHECK(d0_bignum_mul(ctx->rsa_n, ctx->rsa_d, temp1)); if(reject(ctx, pass)) + { + UNLOCKTEMPS(); continue; + } if(d0_bignum_isprime(temp1, 10) == 0) + { + UNLOCKTEMPS(); continue; + } CHECK(d0_bignum_sub(temp3, temp1, one)); CHECK(d0_bignum_gcd(temp4, NULL, NULL, temp3, ctx->rsa_e)); if(!d0_bignum_cmp(temp4, one)) + { + // we do NOT unlock, as we still need temp3 break; + } + UNLOCKTEMPS(); if(++gcdfail == 3) return 0; ++gcdfail; } - // ctx->rsa_d = ctx->rsa_e^-1 mod (temp0-1)(temp1-1) - CHECK(d0_bignum_mul(temp0, temp2, temp3)); + // ctx->rsa_d = ctx->rsa_e^-1 mod (ctx->rsa_d-1)(temp1-1) + CHECK(d0_bignum_sub(temp2, ctx->rsa_d, one)); // we can't reuse the value from above because temps were unlocked + CHECK(d0_bignum_mul(ctx->rsa_d, temp2, temp3)); CHECK(d0_bignum_mod_inv(ctx->rsa_d, ctx->rsa_e, temp0)); + UNLOCKTEMPS(); return 1; fail: + UNLOCKTEMPS(); return 0; } @@ -309,7 +384,7 @@ D0_WARN_UNUSED_RESULT D0_BOOL d0_longhash_destructive(unsigned char *convbuf, si D0_WARN_UNUSED_RESULT D0_BOOL d0_longhash_bignum(const d0_bignum_t *in, unsigned char *outbuf, size_t outbuflen) { - static unsigned char convbuf[1024]; + static __thread unsigned char convbuf[1024]; size_t sz; CHECK(d0_bignum_export_unsigned(in, convbuf, sizeof(convbuf)) >= 0); @@ -374,7 +449,7 @@ D0_WARN_UNUSED_RESULT D0_BOOL d0_blind_id_generate_private_key_fastreject(d0_bli if(reject) CHECK(d0_rsa_generate_key_fastreject(k+1, reject, ctx, pass)); // must fit G for sure else - CHECK(d0_rsa_generate_key(k+1, ctx->rsa_e, ctx->rsa_d, ctx->rsa_n)); // must fit G for sure + CHECK(d0_rsa_generate_key(k+1, ctx)); // must fit G for sure return 1; fail: return 0; @@ -456,7 +531,7 @@ fail: D0_WARN_UNUSED_RESULT D0_BOOL d0_blind_id_fingerprint64_public_key(const d0_blind_id_t *ctx, char *outbuf, size_t *outbuflen) { d0_iobuf_t *out = NULL; - static unsigned char convbuf[2048]; + static __thread unsigned char convbuf[2048]; d0_iobuf_t *conv = NULL; size_t sz, n; @@ -529,27 +604,30 @@ fail: D0_WARN_UNUSED_RESULT D0_BOOL d0_blind_id_generate_private_id_start(d0_blind_id_t *ctx) { - // temps: temp0 = order + USINGTEMPS(); // temps: temp0 = order USING(schnorr_G); REPLACING(schnorr_s); REPLACING(schnorr_g_to_s); + LOCKTEMPS(); CHECK(d0_dl_get_order(temp0, ctx->schnorr_G)); CHECK_ASSIGN(ctx->schnorr_s, d0_bignum_rand_range(ctx->schnorr_s, zero, temp0)); CHECK_ASSIGN(ctx->schnorr_g_to_s, d0_bignum_mod_pow(ctx->schnorr_g_to_s, four, ctx->schnorr_s, ctx->schnorr_G)); CHECK_ASSIGN(ctx->schnorr_H_g_to_s_signature, d0_bignum_zero(ctx->schnorr_H_g_to_s_signature)); + UNLOCKTEMPS(); return 1; fail: + UNLOCKTEMPS(); return 0; } D0_WARN_UNUSED_RESULT D0_BOOL d0_blind_id_generate_private_id_request(d0_blind_id_t *ctx, char *outbuf, size_t *outbuflen) { d0_iobuf_t *out = NULL; - static unsigned char shabuf[2048]; + static __thread unsigned char shabuf[2048]; size_t sz; - // temps: temp0 rsa_blind_signature_camouflage^challenge, temp1 (4^s)*rsa_blind_signature_camouflage^challenge + USINGTEMPS(); // temps: temp0 rsa_blind_signature_camouflage^challenge, temp1 (4^s)*rsa_blind_signature_camouflage^challenge USING(rsa_n); USING(rsa_e); USING(schnorr_g_to_s); REPLACING(rsa_blind_signature_camouflage); @@ -559,6 +637,7 @@ D0_WARN_UNUSED_RESULT D0_BOOL d0_blind_id_generate_private_id_request(d0_blind_i CHECK(d0_bignum_mod_pow(temp0, ctx->rsa_blind_signature_camouflage, ctx->rsa_e, ctx->rsa_n)); // we will actually sign HA(4^s) to prevent a malleability attack! + LOCKTEMPS(); CHECK(d0_bignum_mov(temp2, ctx->schnorr_g_to_s)); sz = (d0_bignum_size(ctx->rsa_n) + 7) / 8; // this is too long, so we have to take the value % rsa_n when "decrypting" if(sz > sizeof(shabuf)) @@ -569,9 +648,11 @@ D0_WARN_UNUSED_RESULT D0_BOOL d0_blind_id_generate_private_id_request(d0_blind_i // hash complete CHECK(d0_bignum_mod_mul(temp1, temp2, temp0, ctx->rsa_n)); CHECK(d0_iobuf_write_bignum(out, temp1)); + UNLOCKTEMPS(); return d0_iobuf_close(out, outbuflen); fail: + UNLOCKTEMPS(); d0_iobuf_close(out, outbuflen); return 0; } @@ -581,20 +662,23 @@ D0_WARN_UNUSED_RESULT D0_BOOL d0_blind_id_answer_private_id_request(const d0_bli d0_iobuf_t *in = NULL; d0_iobuf_t *out = NULL; - // temps: temp0 input, temp1 temp0^d + USINGTEMPS(); // temps: temp0 input, temp1 temp0^d USING(rsa_d); USING(rsa_n); in = d0_iobuf_open_read(inbuf, inbuflen); out = d0_iobuf_open_write(outbuf, *outbuflen); + LOCKTEMPS(); CHECK(d0_iobuf_read_bignum(in, temp0)); CHECK(d0_bignum_mod_pow(temp1, temp0, ctx->rsa_d, ctx->rsa_n)); CHECK(d0_iobuf_write_bignum(out, temp1)); + UNLOCKTEMPS(); d0_iobuf_close(in, NULL); return d0_iobuf_close(out, outbuflen); fail: + UNLOCKTEMPS(); d0_iobuf_close(in, NULL); d0_iobuf_close(out, outbuflen); return 0; @@ -604,19 +688,23 @@ D0_WARN_UNUSED_RESULT D0_BOOL d0_blind_id_finish_private_id_request(d0_blind_id_ { d0_iobuf_t *in = NULL; - // temps: temp0 input, temp1 rsa_blind_signature_camouflage^-1 + USINGTEMPS(); // temps: temp0 input, temp1 rsa_blind_signature_camouflage^-1 USING(rsa_blind_signature_camouflage); USING(rsa_n); REPLACING(schnorr_H_g_to_s_signature); in = d0_iobuf_open_read(inbuf, inbuflen); + LOCKTEMPS(); + CHECK(d0_iobuf_read_bignum(in, temp0)); CHECK(d0_bignum_mod_inv(temp1, ctx->rsa_blind_signature_camouflage, ctx->rsa_n)); CHECK_ASSIGN(ctx->schnorr_H_g_to_s_signature, d0_bignum_mod_mul(ctx->schnorr_H_g_to_s_signature, temp0, temp1, ctx->rsa_n)); + UNLOCKTEMPS(); return d0_iobuf_close(in, NULL); fail: + UNLOCKTEMPS(); d0_iobuf_close(in, NULL); return 0; } @@ -735,12 +823,12 @@ D0_WARN_UNUSED_RESULT D0_BOOL d0_blind_id_authenticate_with_private_id_start(d0_ // 1. get random r, send HASH(4^r) { d0_iobuf_t *out = NULL; - static unsigned char convbuf[1024]; + static __thread unsigned char convbuf[1024]; d0_iobuf_t *conv = NULL; size_t sz = 0; D0_BOOL failed = 0; - // temps: temp0 order, temp0 4^r + USINGTEMPS(); // temps: temp0 order, temp0 4^r if(is_first) { USING(schnorr_g_to_s); USING(schnorr_H_g_to_s_signature); @@ -761,13 +849,21 @@ D0_WARN_UNUSED_RESULT D0_BOOL d0_blind_id_authenticate_with_private_id_start(d0_ // start schnorr ID scheme // generate random number r; x = g^r; send hash of x, remember r, forget x + LOCKTEMPS(); CHECK(d0_dl_get_order(temp0, ctx->schnorr_G)); +#ifdef RNG_XKCD + CHECK_ASSIGN(ctx->r, d0_bignum_int(ctx->r, 4)); // decided by fair dice roll +#else CHECK_ASSIGN(ctx->r, d0_bignum_rand_range(ctx->r, zero, temp0)); - //CHECK(d0_bignum_mod_pow(temp0, four, ctx->r, ctx->schnorr_G)); +#endif // initialize Signed Diffie Hellmann // we already have the group order in temp1 +#ifdef RNG_XKCD + CHECK_ASSIGN(ctx->t, d0_bignum_int(ctx->t, 4)); // decided by fair dice roll +#else CHECK_ASSIGN(ctx->t, d0_bignum_rand_range(ctx->t, zero, temp0)); +#endif // can we SOMEHOW do this with just one mod_pow? CHECK(d0_bignum_mod_pow(temp0, four, ctx->r, ctx->schnorr_G)); @@ -780,6 +876,7 @@ D0_WARN_UNUSED_RESULT D0_BOOL d0_blind_id_authenticate_with_private_id_start(d0_ CHECK(d0_iobuf_write_bignum(conv, ctx->g_to_t)); CHECK(d0_iobuf_write_packet(conv, msg, msglen)); CHECK(d0_iobuf_write_bignum(conv, temp0)); + UNLOCKTEMPS(); CHECK(d0_iobuf_write_bignum(conv, ctx->g_to_t)); d0_iobuf_close(conv, &sz); conv = NULL; @@ -789,6 +886,7 @@ D0_WARN_UNUSED_RESULT D0_BOOL d0_blind_id_authenticate_with_private_id_start(d0_ return d0_iobuf_close(out, outbuflen); fail: + UNLOCKTEMPS(); d0_iobuf_close(out, outbuflen); return 0; } @@ -801,10 +899,10 @@ D0_WARN_UNUSED_RESULT D0_BOOL d0_blind_id_authenticate_with_private_id_challenge { d0_iobuf_t *in = NULL; d0_iobuf_t *out = NULL; - static unsigned char shabuf[2048]; + static __thread unsigned char shabuf[2048]; size_t sz; - // temps: temp0 order, temp0 signature check + USINGTEMPS(); // temps: temp0 order, temp0 signature check if(is_first) { REPLACING(schnorr_g_to_s); REPLACING(schnorr_H_g_to_s_signature); @@ -840,6 +938,7 @@ D0_WARN_UNUSED_RESULT D0_BOOL d0_blind_id_authenticate_with_private_id_challenge CHECK(d0_bignum_cmp(ctx->schnorr_H_g_to_s_signature, ctx->rsa_n) < 0); // check signature of key (t = k^d, so, t^challenge = k) + LOCKTEMPS(); CHECK(d0_bignum_mod_pow(temp0, ctx->schnorr_H_g_to_s_signature, ctx->rsa_e, ctx->rsa_n)); // we will actually sign SHA(4^s) to prevent a malleability attack! @@ -866,14 +965,24 @@ D0_WARN_UNUSED_RESULT D0_BOOL d0_blind_id_authenticate_with_private_id_challenge CHECK(d0_iobuf_read_packet(in, ctx->msg, &ctx->msglen)); // send challenge +#ifdef RNG_XKCD + CHECK_ASSIGN(ctx->challenge, d0_bignum_int(ctx->challenge, 4)); // decided by fair dice roll +#else CHECK_ASSIGN(ctx->challenge, d0_bignum_rand_bit_atmost(ctx->challenge, SCHNORR_BITS)); +#endif CHECK(d0_iobuf_write_bignum(out, ctx->challenge)); // Diffie Hellmann send + LOCKTEMPS(); CHECK(d0_dl_get_order(temp0, ctx->schnorr_G)); +#ifdef RNG_XKCD + CHECK_ASSIGN(ctx->t, d0_bignum_int(ctx->t, 4)); // decided by fair dice roll +#else CHECK_ASSIGN(ctx->t, d0_bignum_rand_range(ctx->t, zero, temp0)); +#endif CHECK(d0_bignum_mod_pow(temp0, four, ctx->t, ctx->schnorr_G)); CHECK(d0_iobuf_write_bignum(out, temp0)); + UNLOCKTEMPS(); if(status) *status = !!d0_bignum_cmp(ctx->schnorr_H_g_to_s_signature, zero); @@ -882,6 +991,7 @@ D0_WARN_UNUSED_RESULT D0_BOOL d0_blind_id_authenticate_with_private_id_challenge return d0_iobuf_close(out, outbuflen); fail: + UNLOCKTEMPS(); d0_iobuf_close(in, NULL); d0_iobuf_close(out, outbuflen); return 0; @@ -894,13 +1004,14 @@ D0_WARN_UNUSED_RESULT D0_BOOL d0_blind_id_authenticate_with_private_id_response( d0_iobuf_t *in = NULL; d0_iobuf_t *out = NULL; - // temps: 0 order, 1 prod, 2 y, 3 challenge + USINGTEMPS(); // temps: 0 order, 1 prod, 2 y, 3 challenge REPLACING(other_g_to_t); REPLACING(t); USING(schnorr_G); USING(schnorr_s); USING(r); USING(g_to_t); in = d0_iobuf_open_read(inbuf, inbuflen); out = d0_iobuf_open_write(outbuf, *outbuflen); + LOCKTEMPS(); CHECK(d0_iobuf_read_bignum(in, temp3)); CHECK(d0_bignum_cmp(temp3, zero) >= 0); CHECK(d0_bignum_size(temp3) <= SCHNORR_BITS); @@ -909,8 +1020,13 @@ D0_WARN_UNUSED_RESULT D0_BOOL d0_blind_id_authenticate_with_private_id_response( // i.challenge. r + ctx->schnorr_s * temp3 CHECK(d0_dl_get_order(temp0, ctx->schnorr_G)); CHECK(d0_bignum_mod_mul(temp1, ctx->schnorr_s, temp3, temp0)); - CHECK(d0_bignum_mod_add(temp2, temp1, ctx->r, temp0)); +#ifdef D0_BLIND_ID_POSITIVE_PROTOCOL + CHECK(d0_bignum_mod_add(temp2, ctx->r, temp1, temp0)); +#else + CHECK(d0_bignum_mod_sub(temp2, ctx->r, temp1, temp0)); +#endif CHECK(d0_iobuf_write_bignum(out, temp2)); + UNLOCKTEMPS(); // Diffie Hellmann recv CHECK_ASSIGN(ctx->other_g_to_t, d0_iobuf_read_bignum(in, ctx->other_g_to_t)); @@ -923,6 +1039,7 @@ D0_WARN_UNUSED_RESULT D0_BOOL d0_blind_id_authenticate_with_private_id_response( return d0_iobuf_close(out, outbuflen); fail: + UNLOCKTEMPS(); d0_iobuf_close(in, NULL); d0_iobuf_close(out, outbuflen); return 0; @@ -934,25 +1051,32 @@ D0_WARN_UNUSED_RESULT D0_BOOL d0_blind_id_authenticate_with_private_id_verify(d0 // (check using H(g^r) which we know) { d0_iobuf_t *in = NULL; - static unsigned char convbuf[1024]; + static __thread unsigned char convbuf[1024]; d0_iobuf_t *conv = NULL; size_t sz; - // temps: 0 y 1 order + USINGTEMPS(); // temps: 0 y 1 order USING(challenge); USING(schnorr_G); REPLACING(other_g_to_t); in = d0_iobuf_open_read(inbuf, inbuflen); + LOCKTEMPS(); + CHECK(d0_dl_get_order(temp1, ctx->schnorr_G)); CHECK(d0_iobuf_read_bignum(in, temp0)); CHECK(d0_bignum_cmp(temp0, zero) >= 0); CHECK(d0_bignum_cmp(temp0, temp1) < 0); // verify schnorr ID scheme +#ifdef D0_BLIND_ID_POSITIVE_PROTOCOL // we need 4^r = 4^temp0 (g^s)^-challenge CHECK(d0_bignum_mod_inv(temp1, ctx->schnorr_g_to_s, ctx->schnorr_G)); CHECK(d0_bignum_mod_pow(temp2, temp1, ctx->challenge, ctx->schnorr_G)); +#else + // we need 4^r = 4^temp0 (g^s)^challenge + CHECK(d0_bignum_mod_pow(temp2, ctx->schnorr_g_to_s, ctx->challenge, ctx->schnorr_G)); +#endif CHECK(d0_bignum_mod_pow(temp1, four, temp0, ctx->schnorr_G)); CHECK_ASSIGN(temp3, d0_bignum_mod_mul(temp3, temp1, temp2, ctx->schnorr_G)); @@ -967,6 +1091,7 @@ D0_WARN_UNUSED_RESULT D0_BOOL d0_blind_id_authenticate_with_private_id_verify(d0 CHECK(d0_iobuf_write_bignum(conv, ctx->other_g_to_t)); CHECK(d0_iobuf_write_packet(conv, ctx->msg, ctx->msglen)); CHECK(d0_iobuf_write_bignum(conv, temp3)); + UNLOCKTEMPS(); CHECK(d0_iobuf_write_bignum(conv, ctx->other_g_to_t)); d0_iobuf_close(conv, &sz); conv = NULL; @@ -989,6 +1114,7 @@ D0_WARN_UNUSED_RESULT D0_BOOL d0_blind_id_authenticate_with_private_id_verify(d0 return 1; fail: + UNLOCKTEMPS(); d0_iobuf_close(in, NULL); return 0; } @@ -996,36 +1122,43 @@ fail: D0_WARN_UNUSED_RESULT D0_BOOL d0_blind_id_authenticate_with_private_id_generate_missing_signature(d0_blind_id_t *ctx) { size_t sz; - static unsigned char shabuf[2048]; + static __thread unsigned char shabuf[2048]; + USINGTEMPS(); // temps: 2 hash REPLACING(schnorr_H_g_to_s_signature); USING(schnorr_g_to_s); USING(rsa_d); USING(rsa_n); + LOCKTEMPS(); + // we will actually sign SHA(4^s) to prevent a malleability attack! - CHECK(d0_bignum_mov(temp2, ctx->schnorr_g_to_s)); sz = (d0_bignum_size(ctx->rsa_n) + 7) / 8; // this is too long, so we have to take the value % rsa_n when "decrypting" if(sz > sizeof(shabuf)) sz = sizeof(shabuf); - CHECK(d0_longhash_bignum(temp2, shabuf, sz)); + CHECK(d0_longhash_bignum(ctx->schnorr_g_to_s, shabuf, sz)); + LOCKTEMPS(); CHECK(d0_bignum_import_unsigned(temp2, shabuf, sz)); // + 7 / 8 is too large, so let's mod it CHECK(d0_bignum_divmod(NULL, temp1, temp2, ctx->rsa_n)); CHECK(d0_bignum_mod_pow(ctx->schnorr_H_g_to_s_signature, temp1, ctx->rsa_d, ctx->rsa_n)); + + UNLOCKTEMPS(); return 1; fail: + UNLOCKTEMPS(); return 0; } -D0_WARN_UNUSED_RESULT D0_BOOL d0_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) +D0_WARN_UNUSED_RESULT D0_BOOL d0_blind_id_sign_with_private_id_sign_internal(d0_blind_id_t *ctx, D0_BOOL is_first, D0_BOOL send_modulus, D0_BOOL with_msg, const char *message, size_t msglen, char *outbuf, size_t *outbuflen) { d0_iobuf_t *out = NULL; - static unsigned char convbuf[1024]; - static unsigned char shabuf[1024]; + unsigned char *convbuf = NULL; + static __thread unsigned char shabuf[2048]; d0_iobuf_t *conv = NULL; size_t sz = 0; + USINGTEMPS(); // temps: 0 order 1 4^r 2 hash if(is_first) { USING(schnorr_g_to_s); USING(schnorr_H_g_to_s_signature); @@ -1047,43 +1180,62 @@ D0_WARN_UNUSED_RESULT D0_BOOL d0_blind_id_sign_with_private_id_sign(d0_blind_id_ // start schnorr SIGNATURE scheme // generate random number r; x = g^r; send hash of H(m||r), remember r, forget x + LOCKTEMPS(); CHECK(d0_dl_get_order(temp0, ctx->schnorr_G)); CHECK_ASSIGN(ctx->r, d0_bignum_rand_range(ctx->r, zero, temp0)); CHECK(d0_bignum_mod_pow(temp1, four, ctx->r, ctx->schnorr_G)); // hash it, hash it, everybody hash it - conv = d0_iobuf_open_write(convbuf, sizeof(convbuf)); + conv = d0_iobuf_open_write_p((void **) &convbuf, 0); CHECK(d0_iobuf_write_packet(conv, message, msglen)); CHECK(d0_iobuf_write_bignum(conv, temp1)); d0_iobuf_close(conv, &sz); conv = NULL; CHECK(d0_longhash_destructive(convbuf, sz, shabuf, (d0_bignum_size(temp0) + 7) / 8)); + d0_free(convbuf); + convbuf = NULL; CHECK(d0_bignum_import_unsigned(temp2, shabuf, (d0_bignum_size(temp0) + 7) / 8)); CHECK(d0_iobuf_write_bignum(out, temp2)); // multiply with secret, sub k, modulo order CHECK(d0_bignum_mod_mul(temp1, temp2, ctx->schnorr_s, temp0)); +#ifdef D0_BLIND_ID_POSITIVE_PROTOCOL + CHECK(d0_bignum_mod_add(temp2, ctx->r, temp1, temp0)); +#else CHECK(d0_bignum_mod_sub(temp2, ctx->r, temp1, temp0)); +#endif CHECK(d0_iobuf_write_bignum(out, temp2)); + UNLOCKTEMPS(); // write the message itself - CHECK(d0_iobuf_write_packet(out, message, msglen)); + if(with_msg) + CHECK(d0_iobuf_write_packet(out, message, msglen)); return d0_iobuf_close(out, outbuflen); fail: + UNLOCKTEMPS(); d0_iobuf_close(out, outbuflen); return 0; } +D0_WARN_UNUSED_RESULT D0_BOOL d0_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) +{ + return d0_blind_id_sign_with_private_id_sign_internal(ctx, is_first, send_modulus, 1, message, msglen, outbuf, outbuflen); +} +D0_WARN_UNUSED_RESULT D0_BOOL d0_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) +{ + return d0_blind_id_sign_with_private_id_sign_internal(ctx, is_first, send_modulus, 0, message, msglen, outbuf, outbuflen); +} -D0_WARN_UNUSED_RESULT D0_BOOL d0_blind_id_sign_with_private_id_verify(d0_blind_id_t *ctx, D0_BOOL is_first, D0_BOOL recv_modulus, const char *inbuf, size_t inbuflen, char *msg, size_t *msglen, D0_BOOL *status) +D0_WARN_UNUSED_RESULT D0_BOOL d0_blind_id_sign_with_private_id_verify_internal(d0_blind_id_t *ctx, D0_BOOL is_first, D0_BOOL recv_modulus, D0_BOOL with_msg, const char *inbuf, size_t inbuflen, char *msg, size_t *msglen, D0_BOOL *status) { d0_iobuf_t *in = NULL; d0_iobuf_t *conv = NULL; - static unsigned char convbuf[2048]; - static unsigned char shabuf[2048]; + unsigned char *convbuf = NULL; + static __thread unsigned char shabuf[2048]; size_t sz; + USINGTEMPS(); // temps: 0 sig^e 2 g^s 3 g^-s 4 order if(is_first) { REPLACING(schnorr_g_to_s); REPLACING(schnorr_H_g_to_s_signature); @@ -1117,14 +1269,14 @@ D0_WARN_UNUSED_RESULT D0_BOOL d0_blind_id_sign_with_private_id_verify(d0_blind_i CHECK(d0_bignum_cmp(ctx->schnorr_H_g_to_s_signature, ctx->rsa_n) < 0); // check signature of key (t = k^d, so, t^challenge = k) + LOCKTEMPS(); CHECK(d0_bignum_mod_pow(temp0, ctx->schnorr_H_g_to_s_signature, ctx->rsa_e, ctx->rsa_n)); // we will actually sign SHA(4^s) to prevent a malleability attack! - CHECK(d0_bignum_mov(temp2, ctx->schnorr_g_to_s)); sz = (d0_bignum_size(ctx->rsa_n) + 7) / 8; // this is too long, so we have to take the value % rsa_n when "decrypting" if(sz > sizeof(shabuf)) sz = sizeof(shabuf); - CHECK(d0_longhash_bignum(temp2, shabuf, sz)); + CHECK(d0_longhash_bignum(ctx->schnorr_g_to_s, shabuf, sz)); CHECK(d0_bignum_import_unsigned(temp2, shabuf, sz)); // + 7 / 8 is too large, so let's mod it @@ -1141,27 +1293,36 @@ D0_WARN_UNUSED_RESULT D0_BOOL d0_blind_id_sign_with_private_id_verify(d0_blind_i CHECK(d0_dl_get_order(temp4, ctx->schnorr_G)); CHECK(d0_iobuf_read_bignum(in, temp0)); // e == H(m || g^r) CHECK(d0_iobuf_read_bignum(in, temp1)); // x == (r - s*e) mod |G| - CHECK(d0_iobuf_read_packet(in, msg, msglen)); + if(with_msg) + CHECK(d0_iobuf_read_packet(in, msg, msglen)); // VERIFY: g^x * (g^s)^-e = g^(x - s*e) = g^r // verify schnorr ID scheme // we need g^r = g^x (g^s)^e CHECK(d0_bignum_mod_pow(temp2, four, temp1, ctx->schnorr_G)); +#ifdef D0_BLIND_ID_POSITIVE_PROTOCOL + CHECK(d0_bignum_mod_inv(temp3, ctx->schnorr_g_to_s, ctx->schnorr_G)); + CHECK(d0_bignum_mod_pow(temp1, temp3, temp0, ctx->schnorr_G)); +#else CHECK(d0_bignum_mod_pow(temp1, ctx->schnorr_g_to_s, temp0, ctx->schnorr_G)); +#endif CHECK_ASSIGN(temp3, d0_bignum_mod_mul(temp3, temp1, temp2, ctx->schnorr_G)); // temp3 now is g^r // hash it, hash it, everybody hash it - conv = d0_iobuf_open_write(convbuf, sizeof(convbuf)); + conv = d0_iobuf_open_write_p((void **) &convbuf, 0); CHECK(d0_iobuf_write_packet(conv, msg, *msglen)); CHECK(d0_iobuf_write_bignum(conv, temp3)); d0_iobuf_close(conv, &sz); conv = NULL; CHECK(d0_longhash_destructive(convbuf, sz, shabuf, (d0_bignum_size(temp4) + 7) / 8)); + d0_free(convbuf); + convbuf = NULL; CHECK(d0_bignum_import_unsigned(temp1, shabuf, (d0_bignum_size(temp4) + 7) / 8)); // verify signature CHECK(!d0_bignum_cmp(temp0, temp1)); + UNLOCKTEMPS(); if(status) *status = !!d0_bignum_cmp(ctx->schnorr_H_g_to_s_signature, zero); @@ -1170,14 +1331,23 @@ D0_WARN_UNUSED_RESULT D0_BOOL d0_blind_id_sign_with_private_id_verify(d0_blind_i return 1; fail: + UNLOCKTEMPS(); d0_iobuf_close(in, NULL); return 0; } +D0_WARN_UNUSED_RESULT D0_BOOL d0_blind_id_sign_with_private_id_verify(d0_blind_id_t *ctx, D0_BOOL is_first, D0_BOOL recv_modulus, const char *inbuf, size_t inbuflen, char *msg, size_t *msglen, D0_BOOL *status) +{ + return d0_blind_id_sign_with_private_id_verify_internal(ctx, is_first, recv_modulus, 1, inbuf, inbuflen, msg, msglen, status); +} +D0_WARN_UNUSED_RESULT D0_BOOL d0_blind_id_sign_with_private_id_verify_detached(d0_blind_id_t *ctx, D0_BOOL is_first, D0_BOOL recv_modulus, const char *inbuf, size_t inbuflen, const char *msg, size_t msglen, D0_BOOL *status) +{ + return d0_blind_id_sign_with_private_id_verify_internal(ctx, is_first, recv_modulus, 0, inbuf, inbuflen, (char *) msg, &msglen, status); +} D0_WARN_UNUSED_RESULT D0_BOOL d0_blind_id_fingerprint64_public_id(const d0_blind_id_t *ctx, char *outbuf, size_t *outbuflen) { d0_iobuf_t *out = NULL; - static unsigned char convbuf[1024]; + static __thread unsigned char convbuf[1024]; d0_iobuf_t *conv = NULL; size_t sz, n; @@ -1211,13 +1381,19 @@ fail: D0_BOOL d0_blind_id_sessionkey_public_id(const d0_blind_id_t *ctx, char *outbuf, size_t *outbuflen) { + D0_BOOL ret; + + USINGTEMPS(); // temps: temp0 result USING(t); USING(other_g_to_t); USING(schnorr_G); - // temps: temp0 result + LOCKTEMPS(); CHECK(d0_bignum_mod_pow(temp0, ctx->other_g_to_t, ctx->t, ctx->schnorr_G)); - return d0_longhash_bignum(temp0, (unsigned char *) outbuf, *outbuflen); + ret = d0_longhash_bignum(temp0, (unsigned char *) outbuf, *outbuflen); + UNLOCKTEMPS(); + return ret; fail: + UNLOCKTEMPS(); return 0; } @@ -1241,3 +1417,12 @@ void d0_blind_id_util_sha256(char *out, const char *in, size_t n) SHA256_Update(&context, (const unsigned char *) in, n); return SHA256_Final((unsigned char *) out, &context); } + +void d0_blind_id_setmallocfuncs(d0_malloc_t *m, d0_free_t *f) +{ + d0_setmallocfuncs(m, f); +} +void d0_blind_id_setmutexfuncs(d0_createmutex_t *c, d0_destroymutex_t *d, d0_lockmutex_t *l, d0_unlockmutex_t *u) +{ + d0_setmutexfuncs(c, d, l, u); +}