don't violate the bn_check_top assertion in BN_mod_inverse_no_branch()

[oweals/openssl.git] / crypto / bn / bn_blind.c

diff --git a/crypto/bn/bn_blind.c b/crypto/bn/bn_blind.c
index 40e742dbadd64e178c419684729bd91fafe2a8d6..c11fb4ccc2d3e11619c5ad65c33bef7be73d6793 100644 (file)
--- a/crypto/bn/bn_blind.c
+++ b/crypto/bn/bn_blind.c
@@ -131,7 +131,7 @@ struct bn_blinding_st
                          BN_MONT_CTX *m_ctx);
        };
 
-BN_BLINDING *BN_BLINDING_new(const BIGNUM *A, const BIGNUM *Ai, BIGNUM *mod)
+BN_BLINDING *BN_BLINDING_new(const BIGNUM *A, const BIGNUM *Ai, /* const */ BIGNUM *mod)
        {
        BN_BLINDING *ret=NULL;
 
@@ -151,7 +151,12 @@ BN_BLINDING *BN_BLINDING_new(const BIGNUM *A, const BIGNUM *Ai, BIGNUM *mod)
                {
                if ((ret->Ai = BN_dup(Ai)) == NULL) goto err;
                }
-       ret->mod = mod;
+
+       /* save a copy of mod in the BN_BLINDING structure */
+       if ((ret->mod = BN_dup(mod)) == NULL) goto err;
+       if (BN_get_flags(mod, BN_FLG_CONSTTIME) != 0)
+               BN_set_flags(ret->mod, BN_FLG_CONSTTIME);
+
        ret->counter = BN_BLINDING_COUNTER;
        return(ret);
 err:
@@ -167,6 +172,7 @@ void BN_BLINDING_free(BN_BLINDING *r)
        if (r->A  != NULL) BN_free(r->A );
        if (r->Ai != NULL) BN_free(r->Ai);
        if (r->e  != NULL) BN_free(r->e );
+       if (r->mod != NULL) BN_free(r->mod); 
        OPENSSL_free(r);
        }
 
@@ -207,6 +213,8 @@ int BN_BLINDING_convert(BIGNUM *n, BN_BLINDING *b, BN_CTX *ctx)
 
 int BN_BLINDING_convert_ex(BIGNUM *n, BIGNUM *r, BN_BLINDING *b, BN_CTX *ctx)
        {
+       int ret = 1;
+
        bn_check_top(n);
 
        if ((b->A == NULL) || (b->Ai == NULL))
@@ -216,9 +224,13 @@ int BN_BLINDING_convert_ex(BIGNUM *n, BIGNUM *r, BN_BLINDING *b, BN_CTX *ctx)
                }
 
        if (r != NULL)
-               BN_copy(r, b->Ai);
+               {
+               if (!BN_copy(r, b->Ai)) ret=0;
+               }
 
-       return BN_mod_mul(n,n,b->A,b->mod,ctx);
+       if (!BN_mod_mul(n,n,b->A,b->mod,ctx)) ret=0;
+       
+       return ret;
        }
 
 int BN_BLINDING_invert(BIGNUM *n, BN_BLINDING *b, BN_CTX *ctx)
@@ -272,7 +284,7 @@ void BN_BLINDING_set_flags(BN_BLINDING *b, unsigned long flags)
        }
 
 BN_BLINDING *BN_BLINDING_create_param(BN_BLINDING *b,
-       const BIGNUM *e, BIGNUM *m, BN_CTX *ctx,
+       const BIGNUM *e, /* const */ BIGNUM *m, BN_CTX *ctx,
        int (*bn_mod_exp)(BIGNUM *r, const BIGNUM *a, const BIGNUM *p,
                          const BIGNUM *m, BN_CTX *ctx, BN_MONT_CTX *m_ctx),
        BN_MONT_CTX *m_ctx)
@@ -351,4 +363,3 @@ err:
 
        return ret;
 }
-