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Take BoringSSL efb42fb: Make BN_mod_exp_mont_consttime take a const context.

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This commit is contained in:
Brian Smith 2015-11-07 17:03:22 -10:00
commit 291a26ac4a
2 changed files with 16 additions and 16 deletions
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29
crypto/bn/exponentiation.c
View File

@ -864,10 +864,10 @@ static int copy_from_prebuf(BIGNUM *b, int top, unsigned char *buf, int idx,
*/
int BN_mod_exp_mont_consttime(BIGNUM *rr, const BIGNUM *a, const BIGNUM *p,
const BIGNUM *m, BN_CTX *ctx,
BN_MONT_CTX *in_mont) {
const BN_MONT_CTX *mont) {
int i, bits, ret = 0, window, wvalue;
int top;
BN_MONT_CTX *mont = NULL;
BN_MONT_CTX *new_mont = NULL;
int numPowers;
unsigned char *powerbufFree = NULL;
@ -890,15 +890,13 @@ int BN_mod_exp_mont_consttime(BIGNUM *rr, const BIGNUM *a, const BIGNUM *p,
BN_CTX_start(ctx);
/* Allocate a montgomery context if it was not supplied by the caller.
* If this is not done, things will break in the montgomery part. */
if (in_mont != NULL) {
mont = in_mont;
} else {
mont = BN_MONT_CTX_new();
if (mont == NULL || !BN_MONT_CTX_set(mont, m, ctx)) {
/* Allocate a montgomery context if it was not supplied by the caller. */
if (mont == NULL) {
new_mont = BN_MONT_CTX_new();
if (new_mont == NULL || !BN_MONT_CTX_set(new_mont, m, ctx)) {
goto err;
}
mont = new_mont;
}
#ifdef RSAZ_ENABLED
@ -997,7 +995,7 @@ int BN_mod_exp_mont_consttime(BIGNUM *rr, const BIGNUM *a, const BIGNUM *p,
/* Dedicated window==4 case improves 512-bit RSA sign by ~15%, but as
* 512-bit RSA is hardly relevant, we omit it to spare size... */
if (window == 5 && top > 1) {
BN_ULONG *np = mont->N.d, *n0 = mont->n0, *np2;
const BN_ULONG *np = mont->N.d, *n0 = mont->n0, *np2;
/* BN_to_montgomery can contaminate words above .top
* [in BN_DEBUG[_DEBUG] build]... */
@ -1011,9 +1009,11 @@ int BN_mod_exp_mont_consttime(BIGNUM *rr, const BIGNUM *a, const BIGNUM *p,
if (top & 7) {
np2 = np;
} else {
for (np2 = am.d + top, i = 0; i < top; i++) {
np2[2 * i] = np[i];
BN_ULONG *np_double = am.d + top;
for (i = 0; i < top; i++) {
np_double[2 * i] = np[i];
}
np2 = np_double;
}
bn_scatter5(tmp.d, top, powerbuf, 0);
@ -1178,10 +1178,9 @@ int BN_mod_exp_mont_consttime(BIGNUM *rr, const BIGNUM *a, const BIGNUM *p,
goto err;
}
ret = 1;
err:
if (in_mont == NULL) {
BN_MONT_CTX_free(mont);
}
BN_MONT_CTX_free(new_mont);
if (powerbuf != NULL) {
OPENSSL_cleanse(powerbuf, powerbufLen);
OPENSSL_free(powerbufFree);

3
include/openssl/bn.h
View File

@ -727,7 +727,8 @@ OPENSSL_EXPORT int BN_mod_exp_mont(BIGNUM *r, const BIGNUM *a, const BIGNUM *p,
OPENSSL_EXPORT int BN_mod_exp_mont_consttime(BIGNUM *rr, const BIGNUM *a,
const BIGNUM *p, const BIGNUM *m,
BN_CTX *ctx, BN_MONT_CTX *in_mont);
BN_CTX *ctx,
const BN_MONT_CTX *mont);
OPENSSL_EXPORT int BN_mod_exp_mont_word(BIGNUM *r, BN_ULONG a, const BIGNUM *p,
const BIGNUM *m, BN_CTX *ctx,