mirror of https://github.com/lukechilds/komodo.git
Pieter Wuille
13 years ago
committed by
Pieter Wuille
9 changed files with 177 additions and 136 deletions
@ -0,0 +1,117 @@ |
|||
// Copyright (c) 2011 The Bitcoin developers
|
|||
// Distributed under the MIT/X11 software license, see the accompanying
|
|||
// file license.txt or http://www.opensource.org/licenses/mit-license.php.
|
|||
|
|||
#include <openssl/ec.h> |
|||
#include <openssl/ecdsa.h> |
|||
|
|||
// Generate a private key from just the secret parameter
|
|||
int EC_KEY_regenerate_key(EC_KEY *eckey, BIGNUM *priv_key) |
|||
{ |
|||
int ok = 0; |
|||
BN_CTX *ctx = NULL; |
|||
EC_POINT *pub_key = NULL; |
|||
|
|||
if (!eckey) return 0; |
|||
|
|||
const EC_GROUP *group = EC_KEY_get0_group(eckey); |
|||
|
|||
if ((ctx = BN_CTX_new()) == NULL) |
|||
goto err; |
|||
|
|||
pub_key = EC_POINT_new(group); |
|||
|
|||
if (pub_key == NULL) |
|||
goto err; |
|||
|
|||
if (!EC_POINT_mul(group, pub_key, priv_key, NULL, NULL, ctx)) |
|||
goto err; |
|||
|
|||
EC_KEY_set_private_key(eckey,priv_key); |
|||
EC_KEY_set_public_key(eckey,pub_key); |
|||
|
|||
ok = 1; |
|||
|
|||
err: |
|||
|
|||
if (pub_key) |
|||
EC_POINT_free(pub_key); |
|||
if (ctx != NULL) |
|||
BN_CTX_free(ctx); |
|||
|
|||
return(ok); |
|||
} |
|||
|
|||
// Perform ECDSA key recovery (see SEC1 4.1.6) for curves over (mod p)-fields
|
|||
// recid selects which key is recovered
|
|||
// if check is nonzero, additional checks are performed
|
|||
int ECDSA_SIG_recover_key_GFp(EC_KEY *eckey, ECDSA_SIG *ecsig, const unsigned char *msg, int msglen, int recid, int check) |
|||
{ |
|||
if (!eckey) return 0; |
|||
|
|||
int ret = 0; |
|||
BN_CTX *ctx = NULL; |
|||
|
|||
BIGNUM *x = NULL; |
|||
BIGNUM *e = NULL; |
|||
BIGNUM *order = NULL; |
|||
BIGNUM *sor = NULL; |
|||
BIGNUM *eor = NULL; |
|||
BIGNUM *field = NULL; |
|||
EC_POINT *R = NULL; |
|||
EC_POINT *O = NULL; |
|||
EC_POINT *Q = NULL; |
|||
BIGNUM *rr = NULL; |
|||
BIGNUM *zero = NULL; |
|||
int n = 0; |
|||
int i = recid / 2; |
|||
|
|||
const EC_GROUP *group = EC_KEY_get0_group(eckey); |
|||
if ((ctx = BN_CTX_new()) == NULL) { ret = -1; goto err; } |
|||
BN_CTX_start(ctx); |
|||
order = BN_CTX_get(ctx); |
|||
if (!EC_GROUP_get_order(group, order, ctx)) { ret = -2; goto err; } |
|||
x = BN_CTX_get(ctx); |
|||
if (!BN_copy(x, order)) { ret=-1; goto err; } |
|||
if (!BN_mul_word(x, i)) { ret=-1; goto err; } |
|||
if (!BN_add(x, x, ecsig->r)) { ret=-1; goto err; } |
|||
field = BN_CTX_get(ctx); |
|||
if (!EC_GROUP_get_curve_GFp(group, field, NULL, NULL, ctx)) { ret=-2; goto err; } |
|||
if (BN_cmp(x, field) >= 0) { ret=0; goto err; } |
|||
if ((R = EC_POINT_new(group)) == NULL) { ret = -2; goto err; } |
|||
if (!EC_POINT_set_compressed_coordinates_GFp(group, R, x, recid % 2, ctx)) { ret=0; goto err; } |
|||
if (check) |
|||
{ |
|||
if ((O = EC_POINT_new(group)) == NULL) { ret = -2; goto err; } |
|||
if (!EC_POINT_mul(group, O, NULL, R, order, ctx)) { ret=-2; goto err; } |
|||
if (!EC_POINT_is_at_infinity(group, O)) { ret = 0; goto err; } |
|||
} |
|||
if ((Q = EC_POINT_new(group)) == NULL) { ret = -2; goto err; } |
|||
n = EC_GROUP_get_degree(group); |
|||
e = BN_CTX_get(ctx); |
|||
if (!BN_bin2bn(msg, msglen, e)) { ret=-1; goto err; } |
|||
if (8*msglen > n) BN_rshift(e, e, 8-(n & 7)); |
|||
zero = BN_CTX_get(ctx); |
|||
if (!BN_zero(zero)) { ret=-1; goto err; } |
|||
if (!BN_mod_sub(e, zero, e, order, ctx)) { ret=-1; goto err; } |
|||
rr = BN_CTX_get(ctx); |
|||
if (!BN_mod_inverse(rr, ecsig->r, order, ctx)) { ret=-1; goto err; } |
|||
sor = BN_CTX_get(ctx); |
|||
if (!BN_mod_mul(sor, ecsig->s, rr, order, ctx)) { ret=-1; goto err; } |
|||
eor = BN_CTX_get(ctx); |
|||
if (!BN_mod_mul(eor, e, rr, order, ctx)) { ret=-1; goto err; } |
|||
if (!EC_POINT_mul(group, Q, eor, R, sor, ctx)) { ret=-2; goto err; } |
|||
if (!EC_KEY_set_public_key(eckey, Q)) { ret=-2; goto err; } |
|||
|
|||
ret = 1; |
|||
|
|||
err: |
|||
if (ctx) { |
|||
BN_CTX_end(ctx); |
|||
BN_CTX_free(ctx); |
|||
} |
|||
if (R != NULL) EC_POINT_free(R); |
|||
if (O != NULL) EC_POINT_free(O); |
|||
if (Q != NULL) EC_POINT_free(Q); |
|||
return ret; |
|||
} |
Loading…
Reference in new issue