1 files changed, 3 insertions, 1 deletions

diff --git a/src/lib/libcrypto/hmac/hmac.c b/src/lib/libcrypto/hmac/hmac.c
index 23b7c98f8f..e1ec79e093 100644
--- a/src/lib/libcrypto/hmac/hmac.c
+++ b/src/lib/libcrypto/hmac/hmac.c
@@ -88,9 +88,11 @@ void HMAC_Init(HMAC_CTX *ctx, const void *key, int len,
                 else
                         {
                         memcpy(ctx->key,key,len);
-                        memset(&(ctx->key[len]),0,sizeof(ctx->key)-len);
                         ctx->key_length=len;
                         }
+                if(ctx->key_length != HMAC_MAX_MD_CBLOCK)
+                        memset(&ctx->key[ctx->key_length], 0,
+                                HMAC_MAX_MD_CBLOCK - ctx->key_length);
                 }
 
         if (reset)