diff options
Diffstat (limited to 'board/cr50/dcrypto/dcrypto_p256.c')
| -rw-r--r-- | board/cr50/dcrypto/dcrypto_p256.c | 32 |
1 files changed, 22 insertions, 10 deletions
diff --git a/board/cr50/dcrypto/dcrypto_p256.c b/board/cr50/dcrypto/dcrypto_p256.c index e13e9b51bb..02c4edd9eb 100644 --- a/board/cr50/dcrypto/dcrypto_p256.c +++ b/board/cr50/dcrypto/dcrypto_p256.c @@ -138,7 +138,25 @@ int dcrypto_p256_ecdsa_sign(struct drbg_ctx *drbg, const p256_int *key, const p256_int *message, p256_int *r, p256_int *s) { int result; - p256_int k, rnd; + p256_int nonce; + + /* Pick uniform 0 < k < R */ + result = (p256_hmac_drbg_generate(drbg, &nonce) != HMAC_DRBG_SUCCESS); + + result |= dcrypto_p256_ecdsa_sign_raw(&nonce, key, message, r, s) - 1; + + /* Wipe temp nonce */ + p256_clear(&nonce); + + return result == 0; +} + +int dcrypto_p256_ecdsa_sign_raw(const p256_int *nonce, const p256_int *key, + const p256_int *message, p256_int *r, + p256_int *s) +{ + int result; + p256_int rnd; dcrypto_init_and_lock(); dcrypto_ecc_init(); @@ -148,13 +166,7 @@ int dcrypto_p256_ecdsa_sign(struct drbg_ctx *drbg, const p256_int *key, p256_fast_random(&rnd); CP8W(rnd, &rnd); - /* Pick uniform 0 < k < R */ - result |= (p256_hmac_drbg_generate(drbg, &k) != HMAC_DRBG_SUCCESS); - - CP8WB(k, &k, &rnd); - - /* Wipe temp k */ - p256_clear(&k); + CP8WB(k, nonce, &rnd); CP8W(msg, message); CP8WB(d, key, &rnd); @@ -170,8 +182,8 @@ int dcrypto_p256_ecdsa_sign(struct drbg_ctx *drbg, const p256_int *key, } /* Wipe d,k */ - CP8W(d, &k); - CP8W(k, &k); + CP8W(d, &rnd); + CP8W(k, &rnd); dcrypto_unlock(); return result == 0; |