Tidy up dsa_sign_setup.

This function is not exported, so we don't need the optional BN_CTX
logic. Additionally, the cleanup code can be made a bit simpler and more
idiomatic.

Change-Id: Ib326eab4813fd9de9ac1df8fdc9e470c26aff092
Reviewed-on: https://boringssl-review.googlesource.com/c/32704
Commit-Queue: Adam Langley <agl@google.com>
Reviewed-by: Adam Langley <agl@google.com>
CQ-Verified: CQ bot account: commit-bot@chromium.org <commit-bot@chromium.org>
This commit is contained in:
David Benjamin 2018-10-25 15:25:54 -05:00 committed by CQ bot account: commit-bot@chromium.org
parent 53d9fdd548
commit aa8d29dbd1

View File

@ -860,29 +860,18 @@ int DSA_size(const DSA *dsa) {
return ret; return ret;
} }
static int dsa_sign_setup(const DSA *dsa, BN_CTX *ctx_in, BIGNUM **out_kinv, static int dsa_sign_setup(const DSA *dsa, BN_CTX *ctx, BIGNUM **out_kinv,
BIGNUM **out_r) { BIGNUM **out_r) {
BN_CTX *ctx;
BIGNUM k, *kinv = NULL, *r = NULL;
int ret = 0;
if (!dsa->p || !dsa->q || !dsa->g) { if (!dsa->p || !dsa->q || !dsa->g) {
OPENSSL_PUT_ERROR(DSA, DSA_R_MISSING_PARAMETERS); OPENSSL_PUT_ERROR(DSA, DSA_R_MISSING_PARAMETERS);
return 0; return 0;
} }
int ret = 0;
BIGNUM k;
BN_init(&k); BN_init(&k);
BIGNUM *r = BN_new();
ctx = ctx_in; BIGNUM *kinv = BN_new();
if (ctx == NULL) {
ctx = BN_CTX_new();
if (ctx == NULL) {
goto err;
}
}
r = BN_new();
kinv = BN_new();
if (r == NULL || kinv == NULL || if (r == NULL || kinv == NULL ||
// Get random k // Get random k
!BN_rand_range_ex(&k, 1, dsa->q) || !BN_rand_range_ex(&k, 1, dsa->q) ||
@ -906,28 +895,23 @@ static int dsa_sign_setup(const DSA *dsa, BN_CTX *ctx_in, BIGNUM **out_kinv,
// Compute part of 's = inv(k) (m + xr) mod q' using Fermat's Little // Compute part of 's = inv(k) (m + xr) mod q' using Fermat's Little
// Theorem. // Theorem.
!bn_mod_inverse_prime(kinv, &k, dsa->q, ctx, dsa->method_mont_q)) { !bn_mod_inverse_prime(kinv, &k, dsa->q, ctx, dsa->method_mont_q)) {
OPENSSL_PUT_ERROR(DSA, ERR_R_BN_LIB);
goto err; goto err;
} }
BN_clear_free(*out_kinv); BN_clear_free(*out_kinv);
*out_kinv = kinv; *out_kinv = kinv;
kinv = NULL; kinv = NULL;
BN_clear_free(*out_r); BN_clear_free(*out_r);
*out_r = r; *out_r = r;
r = NULL;
ret = 1; ret = 1;
err: err:
if (!ret) {
OPENSSL_PUT_ERROR(DSA, ERR_R_BN_LIB);
if (r != NULL) {
BN_clear_free(r);
}
}
if (ctx_in == NULL) {
BN_CTX_free(ctx);
}
BN_clear_free(&k); BN_clear_free(&k);
BN_clear_free(r);
BN_clear_free(kinv); BN_clear_free(kinv);
return ret; return ret;
} }