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Add a secp256k1_ecdsa_signature_t type

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This commit is contained in:
Pieter Wuille
2015-07-26 16:00:55 +02:00
parent 23cfa914d2
commit 74a2acdb8a
7 changed files with 353 additions and 259 deletions
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203
src/secp256k1.c
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@@ -108,11 +108,105 @@ int secp256k1_ec_pubkey_serialize(const secp256k1_context_t* ctx, unsigned char
return secp256k1_eckey_pubkey_serialize(&Q, output, outputlen, compressed);
}
int secp256k1_ecdsa_verify(const secp256k1_context_t* ctx, const unsigned char *msg32, const unsigned char *sig, int siglen, const secp256k1_pubkey_t *pubkey) {
static void secp256k1_ecdsa_signature_load(secp256k1_ecdsa_sig_t* s, int* recid, const secp256k1_ecdsa_signature_t* sig) {
if (sizeof(secp256k1_scalar_t) == 32) {
/* When the secp256k1_scalar_t type is exactly 32 byte, use its
* representation inside secp256k1_ecdsa_signature_t, as conversion is very fast.
* Note that secp256k1_ecdsa_signature_save must use the same representation. */
memcpy(&s->r, &sig->data[0], 32);
memcpy(&s->s, &sig->data[32], 32);
} else {
secp256k1_scalar_set_b32(&s->r, &sig->data[0], NULL);
secp256k1_scalar_set_b32(&s->s, &sig->data[32], NULL);
}
if (recid) {
*recid = sig->data[64];
}
}
static void secp256k1_ecdsa_signature_save(secp256k1_ecdsa_signature_t* sig, const secp256k1_ecdsa_sig_t* s, int recid) {
if (sizeof(secp256k1_scalar_t) == 32) {
memcpy(&sig->data[0], &s->r, 32);
memcpy(&sig->data[32], &s->s, 32);
} else {
secp256k1_scalar_get_b32(&sig->data[0], &s->r);
secp256k1_scalar_get_b32(&sig->data[32], &s->s);
}
sig->data[64] = recid;
}
int secp256k1_ecdsa_signature_parse_der(const secp256k1_context_t* ctx, secp256k1_ecdsa_signature_t* sig, const unsigned char *input, int inputlen) {
secp256k1_ecdsa_sig_t s;
(void)ctx;
DEBUG_CHECK(sig != NULL);
DEBUG_CHECK(input != NULL);
if (secp256k1_ecdsa_sig_parse(&s, input, inputlen)) {
secp256k1_ecdsa_signature_save(sig, &s, -1);
return 1;
} else {
memset(sig, 0, sizeof(*sig));
return 0;
}
}
int secp256k1_ecdsa_signature_parse_compact(const secp256k1_context_t* ctx, secp256k1_ecdsa_signature_t* sig, const unsigned char *input64, int recid) {
secp256k1_ecdsa_sig_t s;
int ret = 1;
int overflow = 0;
(void)ctx;
DEBUG_CHECK(sig != NULL);
DEBUG_CHECK(input64 != NULL);
secp256k1_scalar_set_b32(&s.r, &input64[0], &overflow);
ret &= !overflow;
secp256k1_scalar_set_b32(&s.s, &input64[32], &overflow);
ret &= !overflow;
ret &= (recid == -1 || (recid >= 0 && recid < 4));
if (ret) {
secp256k1_ecdsa_signature_save(sig, &s, recid);
} else {
memset(sig, 0, sizeof(*sig));
}
return ret;
}
int secp256k1_ecdsa_signature_serialize_der(const secp256k1_context_t* ctx, unsigned char *output, int *outputlen, const secp256k1_ecdsa_signature_t* sig) {
secp256k1_ecdsa_sig_t s;
(void)ctx;
DEBUG_CHECK(output != NULL);
DEBUG_CHECK(outputlen != NULL);
DEBUG_CHECK(sig != NULL);
secp256k1_ecdsa_signature_load(&s, NULL, sig);
return secp256k1_ecdsa_sig_serialize(output, outputlen, &s);
}
int secp256k1_ecdsa_signature_serialize_compact(const secp256k1_context_t* ctx, unsigned char *output64, int *recid, const secp256k1_ecdsa_signature_t* sig) {
secp256k1_ecdsa_sig_t s;
int rec;
(void)ctx;
DEBUG_CHECK(output64 != NULL);
DEBUG_CHECK(sig != NULL);
secp256k1_ecdsa_signature_load(&s, &rec, sig);
secp256k1_scalar_get_b32(&output64[0], &s.r);
secp256k1_scalar_get_b32(&output64[32], &s.s);
if (recid) {
DEBUG_CHECK(rec >= 0 && rec < 4);
*recid = rec;
}
return 1;
}
int secp256k1_ecdsa_verify(const secp256k1_context_t* ctx, const unsigned char *msg32, const secp256k1_ecdsa_signature_t *sig, const secp256k1_pubkey_t *pubkey) {
secp256k1_ge_t q;
secp256k1_ecdsa_sig_t s;
secp256k1_scalar_t m;
int ret = 0;
DEBUG_CHECK(ctx != NULL);
DEBUG_CHECK(secp256k1_ecmult_context_is_built(&ctx->ecmult_ctx));
DEBUG_CHECK(msg32 != NULL);
@@ -120,16 +214,9 @@ int secp256k1_ecdsa_verify(const secp256k1_context_t* ctx, const unsigned char *
DEBUG_CHECK(pubkey != NULL);
secp256k1_scalar_set_b32(&m, msg32, NULL);
secp256k1_pubkey_load(&q, pubkey);
if (secp256k1_ecdsa_sig_parse(&s, sig, siglen)) {
if (secp256k1_ecdsa_sig_verify(&ctx->ecmult_ctx, &s, &q, &m)) {
/* success is 1, all other values are fail */
ret = 1;
}
}
return ret;
secp256k1_ecdsa_signature_load(&s, NULL, sig);
return secp256k1_ecdsa_sig_verify(&ctx->ecmult_ctx, &s, &q, &m);
}
static int nonce_function_rfc6979(unsigned char *nonce32, const unsigned char *msg32, const unsigned char *key32, unsigned int counter, const void *data) {
@@ -157,9 +244,10 @@ static int nonce_function_rfc6979(unsigned char *nonce32, const unsigned char *m
const secp256k1_nonce_function_t secp256k1_nonce_function_rfc6979 = nonce_function_rfc6979;
const secp256k1_nonce_function_t secp256k1_nonce_function_default = nonce_function_rfc6979;
int secp256k1_ecdsa_sign(const secp256k1_context_t* ctx, const unsigned char *msg32, unsigned char *signature, int *signaturelen, const unsigned char *seckey, secp256k1_nonce_function_t noncefp, const void* noncedata) {
int secp256k1_ecdsa_sign(const secp256k1_context_t* ctx, const unsigned char *msg32, secp256k1_ecdsa_signature_t *signature, const unsigned char *seckey, secp256k1_nonce_function_t noncefp, const void* noncedata) {
secp256k1_ecdsa_sig_t sig;
secp256k1_scalar_t sec, non, msg;
int recid;
int ret = 0;
int overflow = 0;
unsigned int count = 0;
@@ -167,7 +255,6 @@ int secp256k1_ecdsa_sign(const secp256k1_context_t* ctx, const unsigned char *ms
DEBUG_CHECK(secp256k1_ecmult_gen_context_is_built(&ctx->ecmult_gen_ctx));
DEBUG_CHECK(msg32 != NULL);
DEBUG_CHECK(signature != NULL);
DEBUG_CHECK(signaturelen != NULL);
DEBUG_CHECK(seckey != NULL);
if (noncefp == NULL) {
noncefp = secp256k1_nonce_function_default;
@@ -186,101 +273,45 @@ int secp256k1_ecdsa_sign(const secp256k1_context_t* ctx, const unsigned char *ms
secp256k1_scalar_set_b32(&non, nonce32, &overflow);
memset(nonce32, 0, 32);
if (!secp256k1_scalar_is_zero(&non) && !overflow) {
if (secp256k1_ecdsa_sig_sign(&ctx->ecmult_gen_ctx, &sig, &sec, &msg, &non, NULL)) {
if (secp256k1_ecdsa_sig_sign(&ctx->ecmult_gen_ctx, &sig, &sec, &msg, &non, &recid)) {
break;
}
}
count++;
}
if (ret) {
ret = secp256k1_ecdsa_sig_serialize(signature, signaturelen, &sig);
}
secp256k1_scalar_clear(&msg);
secp256k1_scalar_clear(&non);
secp256k1_scalar_clear(&sec);
}
if (!ret) {
*signaturelen = 0;
if (ret) {
secp256k1_ecdsa_signature_save(signature, &sig, recid);
} else {
memset(signature, 0, sizeof(*signature));
}
return ret;
}
int secp256k1_ecdsa_sign_compact(const secp256k1_context_t* ctx, const unsigned char *msg32, unsigned char *sig64, const unsigned char *seckey, secp256k1_nonce_function_t noncefp, const void* noncedata, int *recid) {
secp256k1_ecdsa_sig_t sig;
secp256k1_scalar_t sec, non, msg;
int ret = 0;
int overflow = 0;
unsigned int count = 0;
DEBUG_CHECK(ctx != NULL);
DEBUG_CHECK(secp256k1_ecmult_gen_context_is_built(&ctx->ecmult_gen_ctx));
DEBUG_CHECK(msg32 != NULL);
DEBUG_CHECK(sig64 != NULL);
DEBUG_CHECK(seckey != NULL);
if (noncefp == NULL) {
noncefp = secp256k1_nonce_function_default;
}
secp256k1_scalar_set_b32(&sec, seckey, &overflow);
/* Fail if the secret key is invalid. */
if (!overflow && !secp256k1_scalar_is_zero(&sec)) {
secp256k1_scalar_set_b32(&msg, msg32, NULL);
while (1) {
unsigned char nonce32[32];
ret = noncefp(nonce32, msg32, seckey, count, noncedata);
if (!ret) {
break;
}
secp256k1_scalar_set_b32(&non, nonce32, &overflow);
memset(nonce32, 0, 32);
if (!secp256k1_scalar_is_zero(&non) && !overflow) {
if (secp256k1_ecdsa_sig_sign(&ctx->ecmult_gen_ctx, &sig, &sec, &msg, &non, recid)) {
break;
}
}
count++;
}
if (ret) {
secp256k1_scalar_get_b32(sig64, &sig.r);
secp256k1_scalar_get_b32(sig64 + 32, &sig.s);
}
secp256k1_scalar_clear(&msg);
secp256k1_scalar_clear(&non);
secp256k1_scalar_clear(&sec);
}
if (!ret) {
memset(sig64, 0, 64);
}
return ret;
}
int secp256k1_ecdsa_recover_compact(const secp256k1_context_t* ctx, const unsigned char *msg32, const unsigned char *sig64, secp256k1_pubkey_t *pubkey, int recid) {
int secp256k1_ecdsa_recover(const secp256k1_context_t* ctx, const unsigned char *msg32, const secp256k1_ecdsa_signature_t *signature, secp256k1_pubkey_t *pubkey) {
secp256k1_ge_t q;
secp256k1_ecdsa_sig_t sig;
secp256k1_scalar_t m;
int ret = 0;
int overflow = 0;
int recid;
DEBUG_CHECK(ctx != NULL);
DEBUG_CHECK(secp256k1_ecmult_context_is_built(&ctx->ecmult_ctx));
DEBUG_CHECK(msg32 != NULL);
DEBUG_CHECK(sig64 != NULL);
DEBUG_CHECK(signature != NULL);
DEBUG_CHECK(pubkey != NULL);
DEBUG_CHECK(recid >= 0 && recid <= 3);
secp256k1_scalar_set_b32(&sig.r, sig64, &overflow);
if (!overflow) {
secp256k1_scalar_set_b32(&sig.s, sig64 + 32, &overflow);
if (!overflow) {
secp256k1_scalar_set_b32(&m, msg32, NULL);
ret = secp256k1_ecdsa_sig_recover(&ctx->ecmult_ctx, &sig, &q, &m, recid);
if (ret) {
secp256k1_pubkey_save(pubkey, &q);
} else {
memset(pubkey, 0, sizeof(*pubkey));
}
}
secp256k1_ecdsa_signature_load(&sig, &recid, signature);
DEBUG_CHECK(recid >= 0 && recid < 4);
secp256k1_scalar_set_b32(&m, msg32, NULL);
if (secp256k1_ecdsa_sig_recover(&ctx->ecmult_ctx, &sig, &q, &m, recid)) {
secp256k1_pubkey_save(pubkey, &q);
return 1;
} else {
memset(pubkey, 0, sizeof(*pubkey));
return 0;
}
return ret;
}
int secp256k1_ec_seckey_verify(const secp256k1_context_t* ctx, const unsigned char *seckey) {