Add no signing flag.

[oweals/openssl.git] / crypto / hmac / hmac.c

diff --git a/crypto/hmac/hmac.c b/crypto/hmac/hmac.c
index 72daed13dd9aea462c10a6e5269ba2b59a7c5944..9504aada943bd337f7fef851c5de82f7325f2626 100644 (file)
--- a/crypto/hmac/hmac.c
+++ b/crypto/hmac/hmac.c
@@ -1,4 +1,3 @@
-/* crypto/hmac/hmac.c */
 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
  * All rights reserved.
  *
@@ -172,12 +171,14 @@ size_t HMAC_size(HMAC_CTX *ctx)
 
 HMAC_CTX *HMAC_CTX_new(void)
 {
-    HMAC_CTX *ctx = (HMAC_CTX *)OPENSSL_zalloc(sizeof(HMAC_CTX));
-    if (ctx)
+    HMAC_CTX *ctx = OPENSSL_zalloc(sizeof(HMAC_CTX));
+
+    if (ctx != NULL) {
         if (!HMAC_CTX_reset(ctx)) {
             HMAC_CTX_free(ctx);
-            ctx = NULL;
+            return NULL;
         }
+    }
     return ctx;
 }
 
@@ -249,11 +250,18 @@ unsigned char *HMAC(const EVP_MD *evp_md, const void *key, int key_len,
 {
     HMAC_CTX *c = NULL;
     static unsigned char m[EVP_MAX_MD_SIZE];
+    static const unsigned char dummy_key[1] = {'\0'};
 
     if (md == NULL)
         md = m;
     if ((c = HMAC_CTX_new()) == NULL)
         goto err;
+
+    /* For HMAC_Init_ex, NULL key signals reuse. */
+    if (key == NULL && key_len == 0) {
+        key = dummy_key;
+    }
+
     if (!HMAC_Init_ex(c, key, key_len, evp_md, NULL))
         goto err;
     if (!HMAC_Update(c, d, n))