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Diffstat (limited to 'crypto/bn/bn_blind.c')
-rw-r--r--crypto/bn/bn_blind.c37
1 files changed, 23 insertions, 14 deletions
diff --git a/crypto/bn/bn_blind.c b/crypto/bn/bn_blind.c
index c11fb4ccc2d3..ca7f996bc8a1 100644
--- a/crypto/bn/bn_blind.c
+++ b/crypto/bn/bn_blind.c
@@ -123,7 +123,7 @@ struct bn_blinding_st
BIGNUM *mod; /* just a reference */
unsigned long thread_id; /* added in OpenSSL 0.9.6j and 0.9.7b;
* used only by crypto/rsa/rsa_eay.c, rsa_lib.c */
- unsigned int counter;
+ int counter;
unsigned long flags;
BN_MONT_CTX *m_ctx;
int (*bn_mod_exp)(BIGNUM *r, const BIGNUM *a, const BIGNUM *p,
@@ -157,7 +157,10 @@ BN_BLINDING *BN_BLINDING_new(const BIGNUM *A, const BIGNUM *Ai, /* const */ BIGN
if (BN_get_flags(mod, BN_FLG_CONSTTIME) != 0)
BN_set_flags(ret->mod, BN_FLG_CONSTTIME);
- ret->counter = BN_BLINDING_COUNTER;
+ /* Set the counter to the special value -1
+ * to indicate that this is never-used fresh blinding
+ * that does not need updating before first use. */
+ ret->counter = -1;
return(ret);
err:
if (ret != NULL) BN_BLINDING_free(ret);
@@ -186,7 +189,10 @@ int BN_BLINDING_update(BN_BLINDING *b, BN_CTX *ctx)
goto err;
}
- if (--(b->counter) == 0 && b->e != NULL &&
+ if (b->counter == -1)
+ b->counter = 0;
+
+ if (++b->counter == BN_BLINDING_COUNTER && b->e != NULL &&
!(b->flags & BN_BLINDING_NO_RECREATE))
{
/* re-create blinding parameters */
@@ -201,8 +207,8 @@ int BN_BLINDING_update(BN_BLINDING *b, BN_CTX *ctx)
ret=1;
err:
- if (b->counter == 0)
- b->counter = BN_BLINDING_COUNTER;
+ if (b->counter == BN_BLINDING_COUNTER)
+ b->counter = 0;
return(ret);
}
@@ -223,6 +229,12 @@ int BN_BLINDING_convert_ex(BIGNUM *n, BIGNUM *r, BN_BLINDING *b, BN_CTX *ctx)
return(0);
}
+ if (b->counter == -1)
+ /* Fresh blinding, doesn't need updating. */
+ b->counter = 0;
+ else if (!BN_BLINDING_update(b,ctx))
+ return(0);
+
if (r != NULL)
{
if (!BN_copy(r, b->Ai)) ret=0;
@@ -243,22 +255,19 @@ int BN_BLINDING_invert_ex(BIGNUM *n, const BIGNUM *r, BN_BLINDING *b, BN_CTX *ct
int ret;
bn_check_top(n);
- if ((b->A == NULL) || (b->Ai == NULL))
- {
- BNerr(BN_F_BN_BLINDING_INVERT_EX,BN_R_NOT_INITIALIZED);
- return(0);
- }
if (r != NULL)
ret = BN_mod_mul(n, n, r, b->mod, ctx);
else
- ret = BN_mod_mul(n, n, b->Ai, b->mod, ctx);
-
- if (ret >= 0)
{
- if (!BN_BLINDING_update(b,ctx))
+ if (b->Ai == NULL)
+ {
+ BNerr(BN_F_BN_BLINDING_INVERT_EX,BN_R_NOT_INITIALIZED);
return(0);
+ }
+ ret = BN_mod_mul(n, n, b->Ai, b->mod, ctx);
}
+
bn_check_top(n);
return(ret);
}