diff options
Diffstat (limited to 'src/modules/schnorr/main_impl.h')
| -rw-r--r-- | src/modules/schnorr/main_impl.h | 164 |
1 files changed, 164 insertions, 0 deletions
diff --git a/src/modules/schnorr/main_impl.h b/src/modules/schnorr/main_impl.h new file mode 100644 index 0000000000..fa176a1767 --- /dev/null +++ b/src/modules/schnorr/main_impl.h @@ -0,0 +1,164 @@ +/********************************************************************** + * Copyright (c) 2014-2015 Pieter Wuille * + * Distributed under the MIT software license, see the accompanying * + * file COPYING or http://www.opensource.org/licenses/mit-license.php.* + **********************************************************************/ + +#ifndef SECP256K1_MODULE_SCHNORR_MAIN +#define SECP256K1_MODULE_SCHNORR_MAIN + +#include "include/secp256k1_schnorr.h" +#include "modules/schnorr/schnorr_impl.h" + +static void secp256k1_schnorr_msghash_sha256(unsigned char *h32, const unsigned char *r32, const unsigned char *msg32) { + secp256k1_sha256_t sha; + secp256k1_sha256_initialize(&sha); + secp256k1_sha256_write(&sha, r32, 32); + secp256k1_sha256_write(&sha, msg32, 32); + secp256k1_sha256_finalize(&sha, h32); +} + +static const unsigned char secp256k1_schnorr_algo16[17] = "Schnorr+SHA256 "; + +int secp256k1_schnorr_sign(const secp256k1_context* ctx, unsigned char *sig64, const unsigned char *msg32, const unsigned char *seckey, secp256k1_nonce_function noncefp, const void* noncedata) { + secp256k1_scalar sec, non; + int ret = 0; + int overflow = 0; + unsigned int count = 0; + VERIFY_CHECK(ctx != NULL); + ARG_CHECK(secp256k1_ecmult_gen_context_is_built(&ctx->ecmult_gen_ctx)); + ARG_CHECK(msg32 != NULL); + ARG_CHECK(sig64 != NULL); + ARG_CHECK(seckey != NULL); + if (noncefp == NULL) { + noncefp = secp256k1_nonce_function_default; + } + + secp256k1_scalar_set_b32(&sec, seckey, NULL); + while (1) { + unsigned char nonce32[32]; + ret = noncefp(nonce32, msg32, seckey, secp256k1_schnorr_algo16, (void*)noncedata, count); + if (!ret) { + break; + } + secp256k1_scalar_set_b32(&non, nonce32, &overflow); + memset(nonce32, 0, 32); + if (!secp256k1_scalar_is_zero(&non) && !overflow) { + if (secp256k1_schnorr_sig_sign(&ctx->ecmult_gen_ctx, sig64, &sec, &non, NULL, secp256k1_schnorr_msghash_sha256, msg32)) { + break; + } + } + count++; + } + if (!ret) { + memset(sig64, 0, 64); + } + secp256k1_scalar_clear(&non); + secp256k1_scalar_clear(&sec); + return ret; +} + +int secp256k1_schnorr_verify(const secp256k1_context* ctx, const unsigned char *sig64, const unsigned char *msg32, const secp256k1_pubkey *pubkey) { + secp256k1_ge q; + VERIFY_CHECK(ctx != NULL); + ARG_CHECK(secp256k1_ecmult_context_is_built(&ctx->ecmult_ctx)); + ARG_CHECK(msg32 != NULL); + ARG_CHECK(sig64 != NULL); + ARG_CHECK(pubkey != NULL); + + secp256k1_pubkey_load(ctx, &q, pubkey); + return secp256k1_schnorr_sig_verify(&ctx->ecmult_ctx, sig64, &q, secp256k1_schnorr_msghash_sha256, msg32); +} + +int secp256k1_schnorr_recover(const secp256k1_context* ctx, secp256k1_pubkey *pubkey, const unsigned char *sig64, const unsigned char *msg32) { + secp256k1_ge q; + + VERIFY_CHECK(ctx != NULL); + ARG_CHECK(secp256k1_ecmult_context_is_built(&ctx->ecmult_ctx)); + ARG_CHECK(msg32 != NULL); + ARG_CHECK(sig64 != NULL); + ARG_CHECK(pubkey != NULL); + + if (secp256k1_schnorr_sig_recover(&ctx->ecmult_ctx, sig64, &q, secp256k1_schnorr_msghash_sha256, msg32)) { + secp256k1_pubkey_save(pubkey, &q); + return 1; + } else { + memset(pubkey, 0, sizeof(*pubkey)); + return 0; + } +} + +int secp256k1_schnorr_generate_nonce_pair(const secp256k1_context* ctx, secp256k1_pubkey *pubnonce, unsigned char *privnonce32, const unsigned char *sec32, const unsigned char *msg32, secp256k1_nonce_function noncefp, const void* noncedata) { + int count = 0; + int ret = 1; + secp256k1_gej Qj; + secp256k1_ge Q; + secp256k1_scalar sec; + + VERIFY_CHECK(ctx != NULL); + ARG_CHECK(secp256k1_ecmult_gen_context_is_built(&ctx->ecmult_gen_ctx)); + ARG_CHECK(msg32 != NULL); + ARG_CHECK(sec32 != NULL); + ARG_CHECK(pubnonce != NULL); + ARG_CHECK(privnonce32 != NULL); + + if (noncefp == NULL) { + noncefp = secp256k1_nonce_function_default; + } + + do { + int overflow; + ret = noncefp(privnonce32, sec32, msg32, secp256k1_schnorr_algo16, (void*)noncedata, count++); + if (!ret) { + break; + } + secp256k1_scalar_set_b32(&sec, privnonce32, &overflow); + if (overflow || secp256k1_scalar_is_zero(&sec)) { + continue; + } + secp256k1_ecmult_gen(&ctx->ecmult_gen_ctx, &Qj, &sec); + secp256k1_ge_set_gej(&Q, &Qj); + + secp256k1_pubkey_save(pubnonce, &Q); + break; + } while(1); + + secp256k1_scalar_clear(&sec); + if (!ret) { + memset(pubnonce, 0, sizeof(*pubnonce)); + } + return ret; +} + +int secp256k1_schnorr_partial_sign(const secp256k1_context* ctx, unsigned char *sig64, const unsigned char *msg32, const unsigned char *sec32, const secp256k1_pubkey *pubnonce_others, const unsigned char *secnonce32) { + int overflow = 0; + secp256k1_scalar sec, non; + secp256k1_ge pubnon; + VERIFY_CHECK(ctx != NULL); + ARG_CHECK(secp256k1_ecmult_gen_context_is_built(&ctx->ecmult_gen_ctx)); + ARG_CHECK(msg32 != NULL); + ARG_CHECK(sig64 != NULL); + ARG_CHECK(sec32 != NULL); + ARG_CHECK(secnonce32 != NULL); + ARG_CHECK(pubnonce_others != NULL); + + secp256k1_scalar_set_b32(&sec, sec32, &overflow); + if (overflow || secp256k1_scalar_is_zero(&sec)) { + return -1; + } + secp256k1_scalar_set_b32(&non, secnonce32, &overflow); + if (overflow || secp256k1_scalar_is_zero(&non)) { + return -1; + } + secp256k1_pubkey_load(ctx, &pubnon, pubnonce_others); + return secp256k1_schnorr_sig_sign(&ctx->ecmult_gen_ctx, sig64, &sec, &non, &pubnon, secp256k1_schnorr_msghash_sha256, msg32); +} + +int secp256k1_schnorr_partial_combine(const secp256k1_context* ctx, unsigned char *sig64, const unsigned char * const *sig64sin, size_t n) { + ARG_CHECK(sig64 != NULL); + ARG_CHECK(n >= 1); + ARG_CHECK(sig64sin != NULL); + return secp256k1_schnorr_sig_combine(sig64, n, sig64sin); +} + +#endif |