don't let BN_CTX_free(NULL) segfault

[openssl.git] / crypto / bn / bn_mont.c

diff --git a/crypto/bn/bn_mont.c b/crypto/bn/bn_mont.c
index 61416483cb26761b113935857fc677a5081eac4d..6bcc9ad2e762f11f51cb0b135f00263c4c3da12f 100644 (file)
--- a/crypto/bn/bn_mont.c
+++ b/crypto/bn/bn_mont.c
@@ -350,3 +350,21 @@ BN_MONT_CTX *BN_MONT_CTX_copy(BN_MONT_CTX *to, BN_MONT_CTX *from)
        return(to);
        }
 
+BN_MONT_CTX *BN_MONT_CTX_set_locked(BN_MONT_CTX **pmont, int lock,
+                                       const BIGNUM *mod, BN_CTX *ctx)
+       {
+       if (*pmont)
+               return *pmont;
+       CRYPTO_w_lock(lock);
+       if (!*pmont)
+               {
+               *pmont = BN_MONT_CTX_new();
+               if (*pmont && !BN_MONT_CTX_set(*pmont, mod, ctx))
+                       {
+                       BN_MONT_CTX_free(*pmont);
+                       *pmont = NULL;
+                       }
+               }
+       CRYPTO_w_unlock(lock);
+       return *pmont;
+       }