- if (BN_is_negative(r0))
- if (!BN_add(r0,r0,rsa->p)) goto err;
- if (!BN_mul(r1,r0,rsa->q,ctx)) goto err;
- if (!BN_add(r0,r1,m1)) goto err;
-
- if (rsa->e && rsa->n)
- {
- if (!rsa->meth->bn_mod_exp(vrfy,r0,rsa->e,rsa->n,ctx,rsa->_method_mod_n)) goto err;
- /* If 'I' was greater than (or equal to) rsa->n, the operation
- * will be equivalent to using 'I mod n'. However, the result of
- * the verify will *always* be less than 'n' so we don't check
- * for absolute equality, just congruency. */
- if (!BN_sub(vrfy, vrfy, I)) goto err;
- if (!BN_mod(vrfy, vrfy, rsa->n, ctx)) goto err;
- if (BN_is_negative(vrfy))
- if (!BN_add(vrfy, vrfy, rsa->n)) goto err;
- if (!BN_is_zero(vrfy))
- /* 'I' and 'vrfy' aren't congruent mod n. Don't leak
- * miscalculated CRT output, just do a raw (slower)
- * mod_exp and return that instead. */
- if (!rsa->meth->bn_mod_exp(r0,I,rsa->d,rsa->n,ctx,
- rsa->_method_mod_n)) goto err;
- }
- ret=1;
-err:
- BN_CTX_end(ctx);
- return(ret);
- }
+ if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME)) {
+ BN_init(&local_p);
+ p = &local_p;
+ BN_with_flags(p, rsa->p, BN_FLG_CONSTTIME);
+
+ BN_init(&local_q);
+ q = &local_q;
+ BN_with_flags(q, rsa->q, BN_FLG_CONSTTIME);
+ } else {
+ p = rsa->p;
+ q = rsa->q;
+ }
+
+ if (rsa->flags & RSA_FLAG_CACHE_PRIVATE) {
+ if (!BN_MONT_CTX_set_locked
+ (&rsa->_method_mod_p, CRYPTO_LOCK_RSA, p, ctx))
+ goto err;
+ if (!BN_MONT_CTX_set_locked
+ (&rsa->_method_mod_q, CRYPTO_LOCK_RSA, q, ctx))
+ goto err;
+ }
+ }
+
+ if (rsa->flags & RSA_FLAG_CACHE_PUBLIC)
+ if (!BN_MONT_CTX_set_locked
+ (&rsa->_method_mod_n, CRYPTO_LOCK_RSA, rsa->n, ctx))
+ goto err;
+
+ /* compute I mod q */
+ if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME)) {
+ c = &local_c;
+ BN_with_flags(c, I, BN_FLG_CONSTTIME);
+ if (!BN_mod(r1, c, rsa->q, ctx))
+ goto err;
+ } else {
+ if (!BN_mod(r1, I, rsa->q, ctx))
+ goto err;
+ }
+
+ /* compute r1^dmq1 mod q */
+ if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME)) {
+ dmq1 = &local_dmq1;
+ BN_with_flags(dmq1, rsa->dmq1, BN_FLG_CONSTTIME);
+ } else
+ dmq1 = rsa->dmq1;
+ if (!rsa->meth->bn_mod_exp(m1, r1, dmq1, rsa->q, ctx, rsa->_method_mod_q))
+ goto err;
+
+ /* compute I mod p */
+ if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME)) {
+ c = &local_c;
+ BN_with_flags(c, I, BN_FLG_CONSTTIME);
+ if (!BN_mod(r1, c, rsa->p, ctx))
+ goto err;
+ } else {
+ if (!BN_mod(r1, I, rsa->p, ctx))
+ goto err;
+ }
+
+ /* compute r1^dmp1 mod p */
+ if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME)) {
+ dmp1 = &local_dmp1;
+ BN_with_flags(dmp1, rsa->dmp1, BN_FLG_CONSTTIME);
+ } else
+ dmp1 = rsa->dmp1;
+ if (!rsa->meth->bn_mod_exp(r0, r1, dmp1, rsa->p, ctx, rsa->_method_mod_p))
+ goto err;
+
+ if (!BN_sub(r0, r0, m1))
+ goto err;
+ /*
+ * This will help stop the size of r0 increasing, which does affect the
+ * multiply if it optimised for a power of 2 size
+ */
+ if (BN_is_negative(r0))
+ if (!BN_add(r0, r0, rsa->p))
+ goto err;
+
+ if (!BN_mul(r1, r0, rsa->iqmp, ctx))
+ goto err;
+
+ /* Turn BN_FLG_CONSTTIME flag on before division operation */
+ if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME)) {
+ pr1 = &local_r1;
+ BN_with_flags(pr1, r1, BN_FLG_CONSTTIME);
+ } else
+ pr1 = r1;
+ if (!BN_mod(r0, pr1, rsa->p, ctx))
+ goto err;
+
+ /*
+ * If p < q it is occasionally possible for the correction of adding 'p'
+ * if r0 is negative above to leave the result still negative. This can
+ * break the private key operations: the following second correction
+ * should *always* correct this rare occurrence. This will *never* happen
+ * with OpenSSL generated keys because they ensure p > q [steve]
+ */
+ if (BN_is_negative(r0))
+ if (!BN_add(r0, r0, rsa->p))
+ goto err;
+ if (!BN_mul(r1, r0, rsa->q, ctx))
+ goto err;
+ if (!BN_add(r0, r1, m1))
+ goto err;
+
+ if (rsa->e && rsa->n) {
+ if (!rsa->
+ meth->bn_mod_exp(vrfy, r0, rsa->e, rsa->n, ctx,
+ rsa->_method_mod_n))
+ goto err;
+ /*
+ * If 'I' was greater than (or equal to) rsa->n, the operation will
+ * be equivalent to using 'I mod n'. However, the result of the
+ * verify will *always* be less than 'n' so we don't check for
+ * absolute equality, just congruency.
+ */
+ if (!BN_sub(vrfy, vrfy, I))
+ goto err;
+ if (!BN_mod(vrfy, vrfy, rsa->n, ctx))
+ goto err;
+ if (BN_is_negative(vrfy))
+ if (!BN_add(vrfy, vrfy, rsa->n))
+ goto err;
+ if (!BN_is_zero(vrfy)) {
+ /*
+ * 'I' and 'vrfy' aren't congruent mod n. Don't leak
+ * miscalculated CRT output, just do a raw (slower) mod_exp and
+ * return that instead.
+ */
+
+ BIGNUM local_d;
+ BIGNUM *d = NULL;
+
+ if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME)) {
+ d = &local_d;
+ BN_with_flags(d, rsa->d, BN_FLG_CONSTTIME);
+ } else
+ d = rsa->d;
+ if (!rsa->meth->bn_mod_exp(r0, I, d, rsa->n, ctx,
+ rsa->_method_mod_n))
+ goto err;
+ }
+ }
+ ret = 1;
+ err:
+ BN_CTX_end(ctx);
+ return (ret);
+}