/**
* ECDSA signing method (replaces ossl_ecdsa_sign_sig)
*
* @param dgst hash value to sign
* @param dlen length of the hash value
* @param kinv precomputed inverse k (from the sign_setup method)
* @param rp precomputed rp (from the sign_setup method)
* @param ec private EC signing key
* @return pointer to a ECDSA_SIG structure or NULL if an error occurred
*/
static ECDSA_SIG *pkcs11_ecdsa_sign_sig(const unsigned char *dgst, int dlen,
const BIGNUM *kinv, const BIGNUM *rp, EC_KEY *ec)
{
unsigned char sigret[512]; /* HACK for now */
ECDSA_SIG *sig;
PKCS11_KEY *key;
unsigned int siglen;
BIGNUM *r, *s, *order;
(void)kinv; /* Precomputed values are not used for PKCS#11 */
(void)rp; /* Precomputed values are not used for PKCS#11 */
key = pkcs11_get_ex_data_ec(ec);
if (check_key_fork(key) < 0) {
sign_sig_fn orig_sign_sig;
#if OPENSSL_VERSION_NUMBER >= 0x10100000L && !defined(LIBRESSL_VERSION_NUMBER)
const EC_KEY_METHOD *meth = EC_KEY_OpenSSL();
EC_KEY_METHOD_get_sign((EC_KEY_METHOD *)meth,
NULL, NULL, &orig_sign_sig);
#else
const ECDSA_METHOD *meth = ECDSA_OpenSSL();
orig_sign_sig = meth->ecdsa_do_sign;
#endif
return orig_sign_sig(dgst, dlen, kinv, rp, ec);
}
/* Truncate digest if its byte size is longer than needed */
order = BN_new();
if (order) {
const EC_GROUP *group = EC_KEY_get0_group(ec);
if (group && EC_GROUP_get_order(group, order, NULL)) {
int klen = BN_num_bits(order);
if (klen < 8*dlen)
dlen = (klen+7)/8;
}
BN_free(order);
}
siglen = sizeof sigret;
if (pkcs11_ecdsa_sign(dgst, dlen, sigret, &siglen, key) <= 0)
return NULL;
r = BN_bin2bn(sigret, siglen/2, NULL);
s = BN_bin2bn(sigret + siglen/2, siglen/2, NULL);
sig = ECDSA_SIG_new();
if (sig == NULL)
return NULL;
#if OPENSSL_VERSION_NUMBER >= 0x10100000L && !defined(LIBRESSL_VERSION_NUMBER)
ECDSA_SIG_set0(sig, r, s);
#else
BN_free(sig->r);
sig->r = r;
BN_free(sig->s);
sig->s = s;
#endif
return sig;
}
/**
* ECDSA signing method (replaces ossl_ecdsa_sign_sig)
*
* @param dgst hash value to sign
* @param dlen length of the hash value
* @param kinv precomputed inverse k (from the sign_setup method)
* @param rp precomputed rp (from the sign_setup method)
* @param ec private EC signing key
* @return pointer to a ECDSA_SIG structure or NULL if an error occurred
*/
static ECDSA_SIG *pkcs11_ecdsa_sign_sig(const unsigned char *dgst, int dlen,
const BIGNUM *kinv, const BIGNUM *rp, EC_KEY *ec)
{
unsigned char sigret[512]; /* HACK for now */
ECDSA_SIG *sig;
PKCS11_KEY *key;
unsigned int siglen;
BIGNUM *r, *s, *order;
(void)kinv; /* Precomputed values are not used for PKCS#11 */
(void)rp; /* Precomputed values are not used for PKCS#11 */
#if OPENSSL_VERSION_NUMBER >= 0x10100000L
key = (PKCS11_KEY *)EC_KEY_get_ex_data(ec, ec_ex_index);
#else
key = (PKCS11_KEY *)ECDSA_get_ex_data(ec, ec_ex_index);
#endif
if (key == NULL) {
PKCS11err(PKCS11_F_PKCS11_EC_KEY_SIGN, PKCS11_ALIEN_KEY);
return NULL;
}
/* TODO: Add an atfork check */
/* Truncate digest if its byte size is longer than needed */
order = BN_new();
if (order) {
const EC_GROUP *group = EC_KEY_get0_group(ec);
if (group && EC_GROUP_get_order(group, order, NULL)) {
int klen = BN_num_bits(order);
if (klen < 8*dlen)
dlen = (klen+7)/8;
}
BN_free(order);
}
siglen = sizeof sigret;
if (pkcs11_ecdsa_sign(dgst, dlen, sigret, &siglen, key) <= 0)
return NULL;
sig = ECDSA_SIG_new();
if (sig == NULL)
return NULL;
#if OPENSSL_VERSION_NUMBER >= 0x10100000L
ECDSA_SIG_get0(&r, &s, sig);
#else
r = sig->r;
s = sig->s;
#endif
BN_bin2bn(sigret, siglen/2, r);
BN_bin2bn(sigret + siglen/2, siglen/2, s);
return sig;
}