Make sure srp_Calc_k() digest operations are checked for error; from

Florian Zumbiehl (florz , florz . de) on tech@

1 files changed, 17 insertions, 9 deletions

diff --git a/src/lib/libcrypto/srp/srp_lib.c b/src/lib/libcrypto/srp/srp_lib.c
index a57ee3640f..19056d4008 100644
--- a/src/lib/libcrypto/srp/srp_lib.c
+++ b/src/lib/libcrypto/srp/srp_lib.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: srp_lib.c,v 1.6 2014/07/10 20:18:51 miod Exp $ */
+/* $OpenBSD: srp_lib.c,v 1.7 2014/07/10 20:22:00 miod Exp $ */
 /* Written by Christophe Renou (christophe.renou@edelweb.fr) with 
  * the precious help of Peter Sylvester (peter.sylvester@edelweb.fr) 
  * for the EdelKey project and contributed to the OpenSSL project 2004.
@@ -84,7 +84,8 @@ static BIGNUM *srp_Calc_k(BIGNUM *N, BIGNUM *g)
         unsigned char digest[SHA_DIGEST_LENGTH];
         unsigned char *tmp;
         EVP_MD_CTX ctxt;
-        int longg ;
+        BIGNUM *ret = NULL;
+        int longg;
         int longN = BN_num_bytes(N);
 
         if ((tmp = malloc(longN)) == NULL)
@@ -92,19 +93,26 @@ static BIGNUM *srp_Calc_k(BIGNUM *N, BIGNUM *g)
         BN_bn2bin(N,tmp);
 
         EVP_MD_CTX_init(&ctxt);
-        EVP_DigestInit_ex(&ctxt, EVP_sha1(), NULL);
-        EVP_DigestUpdate(&ctxt, tmp, longN);
+        if (!EVP_DigestInit_ex(&ctxt, EVP_sha1(), NULL))
+                goto err;
+        if (!EVP_DigestUpdate(&ctxt, tmp, longN))
+                goto err;
 
         memset(tmp, 0, longN);
         longg = BN_bn2bin(g,tmp);
         /* use the zeros behind to pad on left */
-        EVP_DigestUpdate(&ctxt, tmp + longg, longN-longg);
-        EVP_DigestUpdate(&ctxt, tmp, longg);
-        free(tmp);
+        if (!EVP_DigestUpdate(&ctxt, tmp + longg, longN-longg))
+                goto err;
+        if (!EVP_DigestUpdate(&ctxt, tmp, longg))
+                goto err;
 
-        EVP_DigestFinal_ex(&ctxt, digest, NULL);
+        if (!EVP_DigestFinal_ex(&ctxt, digest, NULL))
+                goto err;
+        ret = BN_bin2bn(digest, sizeof(digest), NULL);  
+err:
         EVP_MD_CTX_cleanup(&ctxt);
-        return BN_bin2bn(digest, sizeof(digest), NULL); 
+        free(tmp);
+        return ret;
         }
 
 BIGNUM *SRP_Calc_u(BIGNUM *A, BIGNUM *B, BIGNUM *N)