X-Git-Url: http://de.git.xonotic.org/?p=xonotic%2Fd0_blind_id.git;a=blobdiff_plain;f=d0_blind_id.c;h=3abfb9da74d1b24406fc06acea886fbb3f7ad8d7;hp=e138642c240a7d490a76ee722b68a779c125cf67;hb=09adb6717861941b70ce52996a6159ffe23c5d0c;hpb=503ed535983a12b4333428712ac404d062519782 diff --git a/d0_blind_id.c b/d0_blind_id.c index e138642..3abfb9d 100644 --- a/d0_blind_id.c +++ b/d0_blind_id.c @@ -1,21 +1,37 @@ /* -Blind-ID library for user identification using RSA blind signatures -Copyright (C) 2010 Rudolf Polzer - -This library is free software; you can redistribute it and/or -modify it under the terms of the GNU Lesser General Public -License as published by the Free Software Foundation; either -version 2.1 of the License, or (at your option) any later version. - -This library is distributed in the hope that it will be useful, -but WITHOUT ANY WARRANTY; without even the implied warranty of -MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU -Lesser General Public License for more details. - -You should have received a copy of the GNU Lesser General Public -License along with this library; if not, write to the Free Software -Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA -*/ + * FILE: d0_blind_id.c + * AUTHOR: Rudolf Polzer - divVerent@xonotic.org + * + * Copyright (c) 2010, Rudolf Polzer + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * 3. Neither the name of the copyright holder nor the names of contributors + * may be used to endorse or promote products derived from this software + * without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTOR(S) ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTOR(S) BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + * + * $Format:commit %H$ + * $Id$ + */ #include "d0_blind_id.h" @@ -26,10 +42,10 @@ Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA // our SHA is SHA-256 #define SHA_DIGESTSIZE 32 -const char *sha(const char *in, size_t len) +const char *sha(const unsigned char *in, size_t len) { static char h[32]; - d0_blind_id_util_sha256(h, in, len); + d0_blind_id_util_sha256(h, (const char *) in, len); return h; } @@ -88,7 +104,7 @@ struct d0_blind_id_s static d0_bignum_t *zero, *one, *four, *temp0, *temp1, *temp2, *temp3, *temp4; -WARN_UNUSED_RESULT BOOL d0_blind_id_INITIALIZE(void) +D0_WARN_UNUSED_RESULT D0_BOOL d0_blind_id_INITIALIZE(void) { CHECK(d0_bignum_INITIALIZE()); CHECK_ASSIGN(zero, d0_bignum_int(zero, 0)); @@ -136,7 +152,7 @@ fail: return NULL; } -BOOL d0_dl_generate_key(size_t size, d0_bignum_t *G) +D0_BOOL d0_dl_generate_key(size_t size, d0_bignum_t *G) { // using: temp0 if(size < 16) @@ -158,7 +174,7 @@ fail: return 0; } -BOOL d0_rsa_generate_key(size_t size, const d0_bignum_t *challenge, d0_bignum_t *d, d0_bignum_t *n) +D0_BOOL d0_rsa_generate_key(size_t size, const d0_bignum_t *challenge, d0_bignum_t *d, d0_bignum_t *n) { // uses temp0 to temp4 int fail = 0; @@ -214,7 +230,7 @@ fail: return 0; } -BOOL d0_rsa_generate_key_fastreject(size_t size, d0_fastreject_function reject, d0_blind_id_t *ctx, void *pass) +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 int fail = 0; @@ -273,26 +289,33 @@ fail: return 0; } -WARN_UNUSED_RESULT BOOL d0_longhash_destructive(d0_bignum_t *clobberme, char *outbuf, size_t outbuflen) +D0_WARN_UNUSED_RESULT D0_BOOL d0_longhash_destructive(unsigned char *convbuf, size_t sz, unsigned char *outbuf, size_t outbuflen) { - d0_iobuf_t *out = NULL; - static unsigned char convbuf[1024]; - size_t n, sz; + size_t n, i; n = outbuflen; while(n > SHA_DIGESTSIZE) { - sz = (d0_bignum_size(clobberme) + 7) / 8; - CHECK(d0_bignum_export_unsigned(clobberme, convbuf, sizeof(convbuf)) >= 0); memcpy(outbuf, sha(convbuf, sz), SHA_DIGESTSIZE); outbuf += SHA_DIGESTSIZE; n -= SHA_DIGESTSIZE; - CHECK(d0_bignum_add(clobberme, clobberme, one)); + for(i = 0; i < sz; ++i) + if(++convbuf[i]) + break; // stop until no carry } - sz = (d0_bignum_size(clobberme) + 7) / 8; - CHECK(d0_bignum_export_unsigned(clobberme, convbuf, sizeof(convbuf)) >= 0); memcpy(outbuf, sha(convbuf, sz), n); return 1; +} + +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]; + size_t sz; + + CHECK(d0_bignum_export_unsigned(in, convbuf, sizeof(convbuf)) >= 0); + sz = (d0_bignum_size(in) + 7) / 8; + CHECK(d0_longhash_destructive(convbuf, sz, outbuf, outbuflen)); + return 1; fail: return 0; @@ -316,7 +339,7 @@ void d0_blind_id_clear(d0_blind_id_t *ctx) memset(ctx, 0, sizeof(*ctx)); } -WARN_UNUSED_RESULT BOOL d0_blind_id_copy(d0_blind_id_t *ctx, const d0_blind_id_t *src) +D0_WARN_UNUSED_RESULT D0_BOOL d0_blind_id_copy(d0_blind_id_t *ctx, const d0_blind_id_t *src) { d0_blind_id_clear(ctx); if(src->rsa_n) CHECK_ASSIGN(ctx->rsa_n, d0_bignum_mov(NULL, src->rsa_n)); @@ -341,7 +364,7 @@ fail: return 0; } -WARN_UNUSED_RESULT BOOL d0_blind_id_generate_private_key_fastreject(d0_blind_id_t *ctx, int k, d0_fastreject_function reject, void *pass) +D0_WARN_UNUSED_RESULT D0_BOOL d0_blind_id_generate_private_key_fastreject(d0_blind_id_t *ctx, int k, d0_fastreject_function reject, void *pass) { REPLACING(rsa_e); REPLACING(rsa_d); REPLACING(rsa_n); @@ -357,12 +380,12 @@ fail: return 0; } -WARN_UNUSED_RESULT BOOL d0_blind_id_generate_private_key(d0_blind_id_t *ctx, int k) +D0_WARN_UNUSED_RESULT D0_BOOL d0_blind_id_generate_private_key(d0_blind_id_t *ctx, int k) { return d0_blind_id_generate_private_key_fastreject(ctx, k, NULL, NULL); } -WARN_UNUSED_RESULT BOOL d0_blind_id_read_private_key(d0_blind_id_t *ctx, const char *inbuf, size_t inbuflen) +D0_WARN_UNUSED_RESULT D0_BOOL d0_blind_id_read_private_key(d0_blind_id_t *ctx, const char *inbuf, size_t inbuflen) { d0_iobuf_t *in = NULL; @@ -380,7 +403,7 @@ fail: return 0; } -WARN_UNUSED_RESULT BOOL d0_blind_id_read_public_key(d0_blind_id_t *ctx, const char *inbuf, size_t inbuflen) +D0_WARN_UNUSED_RESULT D0_BOOL d0_blind_id_read_public_key(d0_blind_id_t *ctx, const char *inbuf, size_t inbuflen) { d0_iobuf_t *in = NULL; @@ -396,7 +419,7 @@ fail: return 0; } -WARN_UNUSED_RESULT BOOL d0_blind_id_write_private_key(const d0_blind_id_t *ctx, char *outbuf, size_t *outbuflen) +D0_WARN_UNUSED_RESULT D0_BOOL d0_blind_id_write_private_key(const d0_blind_id_t *ctx, char *outbuf, size_t *outbuflen) { d0_iobuf_t *out = NULL; @@ -413,7 +436,7 @@ fail: return 0; } -WARN_UNUSED_RESULT BOOL d0_blind_id_write_public_key(const d0_blind_id_t *ctx, char *outbuf, size_t *outbuflen) +D0_WARN_UNUSED_RESULT D0_BOOL d0_blind_id_write_public_key(const d0_blind_id_t *ctx, char *outbuf, size_t *outbuflen) { d0_iobuf_t *out = NULL; @@ -430,7 +453,7 @@ fail: return 0; } -WARN_UNUSED_RESULT BOOL d0_blind_id_fingerprint64_public_key(const d0_blind_id_t *ctx, char *outbuf, size_t *outbuflen) +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]; @@ -462,7 +485,7 @@ fail: return 0; } -WARN_UNUSED_RESULT BOOL d0_blind_id_generate_private_id_modulus(d0_blind_id_t *ctx) +D0_WARN_UNUSED_RESULT D0_BOOL d0_blind_id_generate_private_id_modulus(d0_blind_id_t *ctx) { USING(rsa_n); REPLACING(schnorr_G); @@ -474,7 +497,7 @@ fail: return 0; } -WARN_UNUSED_RESULT BOOL d0_blind_id_read_private_id_modulus(d0_blind_id_t *ctx, const char *inbuf, size_t inbuflen) +D0_WARN_UNUSED_RESULT D0_BOOL d0_blind_id_read_private_id_modulus(d0_blind_id_t *ctx, const char *inbuf, size_t inbuflen) { d0_iobuf_t *in = NULL; @@ -489,7 +512,7 @@ fail: return 0; } -WARN_UNUSED_RESULT BOOL d0_blind_id_write_private_id_modulus(const d0_blind_id_t *ctx, char *outbuf, size_t *outbuflen) +D0_WARN_UNUSED_RESULT D0_BOOL d0_blind_id_write_private_id_modulus(const d0_blind_id_t *ctx, char *outbuf, size_t *outbuflen) { d0_iobuf_t *out = NULL; @@ -504,7 +527,7 @@ fail: return 0; } -WARN_UNUSED_RESULT BOOL d0_blind_id_generate_private_id_start(d0_blind_id_t *ctx) +D0_WARN_UNUSED_RESULT D0_BOOL d0_blind_id_generate_private_id_start(d0_blind_id_t *ctx) { // temps: temp0 = order USING(schnorr_G); @@ -520,10 +543,10 @@ fail: return 0; } -WARN_UNUSED_RESULT BOOL d0_blind_id_generate_private_id_request(d0_blind_id_t *ctx, char *outbuf, size_t *outbuflen) +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 convbuf[2048], shabuf[2048]; + static unsigned char shabuf[2048]; size_t sz; // temps: temp0 rsa_blind_signature_camouflage^challenge, temp1 (4^s)*rsa_blind_signature_camouflage^challenge @@ -540,7 +563,7 @@ WARN_UNUSED_RESULT BOOL d0_blind_id_generate_private_id_request(d0_blind_id_t *c 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_destructive(temp2, shabuf, sz)); + CHECK(d0_longhash_bignum(temp2, shabuf, sz)); CHECK(d0_bignum_import_unsigned(temp2, shabuf, sz)); // hash complete @@ -553,7 +576,7 @@ fail: return 0; } -WARN_UNUSED_RESULT BOOL d0_blind_id_answer_private_id_request(const d0_blind_id_t *ctx, const char *inbuf, size_t inbuflen, char *outbuf, size_t *outbuflen) +D0_WARN_UNUSED_RESULT D0_BOOL d0_blind_id_answer_private_id_request(const d0_blind_id_t *ctx, const char *inbuf, size_t inbuflen, char *outbuf, size_t *outbuflen) { d0_iobuf_t *in = NULL; d0_iobuf_t *out = NULL; @@ -577,7 +600,7 @@ fail: return 0; } -WARN_UNUSED_RESULT BOOL d0_blind_id_finish_private_id_request(d0_blind_id_t *ctx, const char *inbuf, size_t inbuflen) +D0_WARN_UNUSED_RESULT D0_BOOL d0_blind_id_finish_private_id_request(d0_blind_id_t *ctx, const char *inbuf, size_t inbuflen) { d0_iobuf_t *in = NULL; @@ -598,7 +621,7 @@ fail: return 0; } -WARN_UNUSED_RESULT BOOL d0_blind_id_read_private_id_request_camouflage(d0_blind_id_t *ctx, const char *inbuf, size_t inbuflen) +D0_WARN_UNUSED_RESULT D0_BOOL d0_blind_id_read_private_id_request_camouflage(d0_blind_id_t *ctx, const char *inbuf, size_t inbuflen) { d0_iobuf_t *in = NULL; @@ -615,7 +638,7 @@ fail: return 0; } -WARN_UNUSED_RESULT BOOL d0_blind_id_write_private_id_request_camouflage(const d0_blind_id_t *ctx, char *outbuf, size_t *outbuflen) +D0_WARN_UNUSED_RESULT D0_BOOL d0_blind_id_write_private_id_request_camouflage(const d0_blind_id_t *ctx, char *outbuf, size_t *outbuflen) { d0_iobuf_t *out = NULL; @@ -632,7 +655,7 @@ fail: return 0; } -WARN_UNUSED_RESULT BOOL d0_blind_id_read_private_id(d0_blind_id_t *ctx, const char *inbuf, size_t inbuflen) +D0_WARN_UNUSED_RESULT D0_BOOL d0_blind_id_read_private_id(d0_blind_id_t *ctx, const char *inbuf, size_t inbuflen) { d0_iobuf_t *in = NULL; @@ -651,7 +674,7 @@ fail: return 0; } -WARN_UNUSED_RESULT BOOL d0_blind_id_read_public_id(d0_blind_id_t *ctx, const char *inbuf, size_t inbuflen) +D0_WARN_UNUSED_RESULT D0_BOOL d0_blind_id_read_public_id(d0_blind_id_t *ctx, const char *inbuf, size_t inbuflen) { d0_iobuf_t *in = NULL; @@ -669,7 +692,7 @@ fail: return 0; } -WARN_UNUSED_RESULT BOOL d0_blind_id_write_private_id(const d0_blind_id_t *ctx, char *outbuf, size_t *outbuflen) +D0_WARN_UNUSED_RESULT D0_BOOL d0_blind_id_write_private_id(const d0_blind_id_t *ctx, char *outbuf, size_t *outbuflen) { d0_iobuf_t *out = NULL; @@ -688,7 +711,7 @@ fail: return 0; } -WARN_UNUSED_RESULT BOOL d0_blind_id_write_public_id(const d0_blind_id_t *ctx, char *outbuf, size_t *outbuflen) +D0_WARN_UNUSED_RESULT D0_BOOL d0_blind_id_write_public_id(const d0_blind_id_t *ctx, char *outbuf, size_t *outbuflen) { d0_iobuf_t *out = NULL; @@ -706,7 +729,7 @@ fail: return 0; } -WARN_UNUSED_RESULT BOOL d0_blind_id_authenticate_with_private_id_start(d0_blind_id_t *ctx, BOOL is_first, BOOL send_modulus, char *msg, size_t msglen, char *outbuf, size_t *outbuflen) +D0_WARN_UNUSED_RESULT D0_BOOL d0_blind_id_authenticate_with_private_id_start(d0_blind_id_t *ctx, D0_BOOL is_first, D0_BOOL send_modulus, const char *msg, size_t msglen, char *outbuf, size_t *outbuflen) // start = // first run: send 4^s, 4^s signature // 1. get random r, send HASH(4^r) @@ -715,7 +738,7 @@ WARN_UNUSED_RESULT BOOL d0_blind_id_authenticate_with_private_id_start(d0_blind_ static unsigned char convbuf[1024]; d0_iobuf_t *conv = NULL; size_t sz = 0; - BOOL failed = 0; + D0_BOOL failed = 0; // temps: temp0 order, temp0 4^r if(is_first) @@ -747,18 +770,8 @@ WARN_UNUSED_RESULT BOOL d0_blind_id_authenticate_with_private_id_start(d0_blind_ CHECK_ASSIGN(ctx->t, d0_bignum_rand_range(ctx->t, zero, temp0)); // can we SOMEHOW do this with just one mod_pow? -#pragma omp parallel default(shared) reduction(||:failed) -#pragma omp sections - { -#pragma omp section - { - MPCHECK(d0_bignum_mod_pow(temp0, four, ctx->r, ctx->schnorr_G)); - } -#pragma omp section - { - MPCHECK_ASSIGN(ctx->g_to_t, d0_bignum_mod_pow(ctx->g_to_t, four, ctx->t, ctx->schnorr_G)); - } - } + CHECK(d0_bignum_mod_pow(temp0, four, ctx->r, ctx->schnorr_G)); + CHECK_ASSIGN(ctx->g_to_t, d0_bignum_mod_pow(ctx->g_to_t, four, ctx->t, ctx->schnorr_G)); CHECK(!failed); // hash it, hash it, everybody hash it @@ -780,7 +793,7 @@ fail: return 0; } -WARN_UNUSED_RESULT BOOL d0_blind_id_authenticate_with_private_id_challenge(d0_blind_id_t *ctx, BOOL is_first, BOOL recv_modulus, const char *inbuf, size_t inbuflen, char *outbuf, size_t *outbuflen, BOOL *status) +D0_WARN_UNUSED_RESULT D0_BOOL d0_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) // first run: get 4^s, 4^s signature // 1. check sig // 2. save HASH(4^r) @@ -834,7 +847,7 @@ WARN_UNUSED_RESULT BOOL d0_blind_id_authenticate_with_private_id_challenge(d0_bl 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_destructive(temp2, shabuf, sz)); + CHECK(d0_longhash_bignum(temp2, shabuf, sz)); CHECK(d0_bignum_import_unsigned(temp2, shabuf, sz)); // + 7 / 8 is too large, so let's mod it @@ -874,7 +887,7 @@ fail: return 0; } -WARN_UNUSED_RESULT BOOL d0_blind_id_authenticate_with_private_id_response(d0_blind_id_t *ctx, const char *inbuf, size_t inbuflen, char *outbuf, size_t *outbuflen) +D0_WARN_UNUSED_RESULT D0_BOOL d0_blind_id_authenticate_with_private_id_response(d0_blind_id_t *ctx, const char *inbuf, size_t inbuflen, char *outbuf, size_t *outbuflen) // 1. read challenge challenge of SCHNORR_BITS // 2. reply with r + s * challenge mod order { @@ -915,7 +928,7 @@ fail: return 0; } -WARN_UNUSED_RESULT BOOL d0_blind_id_authenticate_with_private_id_verify(d0_blind_id_t *ctx, const char *inbuf, size_t inbuflen, char *msg, size_t *msglen, BOOL *status) +D0_WARN_UNUSED_RESULT D0_BOOL d0_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) // 1. read y = r + s * challenge mod order // 2. verify: g^y (g^s)^-challenge = g^(r+s*challenge-s*challenge) = g^r // (check using H(g^r) which we know) @@ -980,7 +993,7 @@ fail: return 0; } -WARN_UNUSED_RESULT BOOL d0_blind_id_authenticate_with_private_id_generate_missing_signature(d0_blind_id_t *ctx) +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]; @@ -993,7 +1006,7 @@ WARN_UNUSED_RESULT BOOL d0_blind_id_authenticate_with_private_id_generate_missin 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_destructive(temp2, shabuf, sz)); + CHECK(d0_longhash_bignum(temp2, shabuf, sz)); CHECK(d0_bignum_import_unsigned(temp2, shabuf, sz)); // + 7 / 8 is too large, so let's mod it @@ -1005,18 +1018,178 @@ fail: return 0; } -WARN_UNUSED_RESULT BOOL d0_blind_id_fingerprint64_public_id(const d0_blind_id_t *ctx, char *outbuf, size_t *outbuflen) +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_iobuf_t *out = NULL; + static unsigned char convbuf[1024]; + static unsigned char shabuf[1024]; + d0_iobuf_t *conv = NULL; + size_t sz = 0; + + if(is_first) + { + USING(schnorr_g_to_s); USING(schnorr_H_g_to_s_signature); + } + USING(schnorr_G); + USING(schnorr_s); + REPLACING(r); + + out = d0_iobuf_open_write(outbuf, *outbuflen); + + if(is_first) + { + // send ID + if(send_modulus) + CHECK(d0_iobuf_write_bignum(out, ctx->schnorr_G)); + CHECK(d0_iobuf_write_bignum(out, ctx->schnorr_g_to_s)); + CHECK(d0_iobuf_write_bignum(out, ctx->schnorr_H_g_to_s_signature)); + } + + // start schnorr SIGNATURE scheme + // generate random number r; x = g^r; send hash of H(m||r), remember r, forget x + 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)); + 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)); + 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)); + CHECK(d0_bignum_mod_sub(temp2, ctx->r, temp1, temp0)); + CHECK(d0_iobuf_write_bignum(out, temp2)); + + // write the message itself + CHECK(d0_iobuf_write_packet(out, message, msglen)); + + return d0_iobuf_close(out, outbuflen); + +fail: + d0_iobuf_close(out, outbuflen); + 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) +{ + d0_iobuf_t *in = NULL; + d0_iobuf_t *conv = NULL; + static unsigned char convbuf[2048]; + static unsigned char shabuf[2048]; + size_t sz; + + if(is_first) + { + REPLACING(schnorr_g_to_s); REPLACING(schnorr_H_g_to_s_signature); + if(recv_modulus) + REPLACING(schnorr_G); + else + USING(schnorr_G); + } + else + { + USING(schnorr_g_to_s); USING(schnorr_H_g_to_s_signature); + USING(schnorr_G); + } + USING(rsa_e); USING(rsa_n); + + in = d0_iobuf_open_read(inbuf, inbuflen); + + if(is_first) + { + if(recv_modulus) + { + CHECK_ASSIGN(ctx->schnorr_G, d0_iobuf_read_bignum(in, ctx->schnorr_G)); + CHECK(d0_bignum_cmp(ctx->schnorr_G, zero) > 0); + CHECK(d0_bignum_cmp(ctx->schnorr_G, ctx->rsa_n) < 0); + } + CHECK_ASSIGN(ctx->schnorr_g_to_s, d0_iobuf_read_bignum(in, ctx->schnorr_g_to_s)); + CHECK(d0_bignum_cmp(ctx->schnorr_g_to_s, zero) >= 0); + CHECK(d0_bignum_cmp(ctx->schnorr_g_to_s, ctx->schnorr_G) < 0); + CHECK_ASSIGN(ctx->schnorr_H_g_to_s_signature, d0_iobuf_read_bignum(in, ctx->schnorr_H_g_to_s_signature)); + CHECK(d0_bignum_cmp(ctx->schnorr_H_g_to_s_signature, zero) >= 0); + 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) + 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_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)); + + // hash complete + if(d0_bignum_cmp(temp0, temp1)) + { + // accept the key anyway, but mark as failed signature! will later return 0 in status + CHECK(d0_bignum_zero(ctx->schnorr_H_g_to_s_signature)); + } + } + + 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)); + + // 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)); + CHECK(d0_bignum_mod_pow(temp1, ctx->schnorr_g_to_s, temp0, ctx->schnorr_G)); + 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)); + 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)); + CHECK(d0_bignum_import_unsigned(temp1, shabuf, (d0_bignum_size(temp4) + 7) / 8)); + + // verify signature + CHECK(!d0_bignum_cmp(temp0, temp1)); + + if(status) + *status = !!d0_bignum_cmp(ctx->schnorr_H_g_to_s_signature, zero); + + d0_iobuf_close(in, NULL); + return 1; + +fail: + d0_iobuf_close(in, NULL); + return 0; +} + +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]; d0_iobuf_t *conv = NULL; size_t sz, n; + USING(rsa_n); + USING(rsa_e); USING(schnorr_g_to_s); out = d0_iobuf_open_write(outbuf, *outbuflen); conv = d0_iobuf_open_write(convbuf, sizeof(convbuf)); + CHECK(d0_iobuf_write_bignum(conv, ctx->rsa_n)); + CHECK(d0_iobuf_write_bignum(conv, ctx->rsa_e)); CHECK(d0_iobuf_write_bignum(conv, ctx->schnorr_g_to_s)); CHECK(d0_iobuf_close(conv, &sz)); conv = NULL; @@ -1036,13 +1209,13 @@ fail: return 0; } -BOOL d0_blind_id_sessionkey_public_id(const d0_blind_id_t *ctx, char *outbuf, size_t *outbuflen) +D0_BOOL d0_blind_id_sessionkey_public_id(const d0_blind_id_t *ctx, char *outbuf, size_t *outbuflen) { USING(t); USING(other_g_to_t); USING(schnorr_G); // temps: temp0 result CHECK(d0_bignum_mod_pow(temp0, ctx->other_g_to_t, ctx->t, ctx->schnorr_G)); - return d0_longhash_destructive(temp0, outbuf, *outbuflen); + return d0_longhash_bignum(temp0, (unsigned char *) outbuf, *outbuflen); fail: return 0;