tiny fix regarding too long keys

git-svn-id: svn://svn.icculus.org/twilight/trunk/darkplaces@8885 d7cf8633-e32d-0410-b094-e92efae38249

diff --git a/hmac.c b/hmac.c
index eb254e21bcbc6ef8898f9fd6f1d83464ce21ddd4..372921d7a096a8786e3e652b9c988f574ace53c2 100644 (file)
--- a/hmac.c
+++ b/hmac.c
@@ -18,6 +18,8 @@ void hmac(
                Host_Error("Invalid hash function used for HMAC - too long hash length");
        if(sizeof(k_xor_ipad) < (size_t) hblock)
                Host_Error("Invalid hash function used for HMAC - too long hash block length");
+       if(sizeof(k_xor_ipad) < (size_t) hlen)
+               Host_Error("Invalid hash function used for HMAC - too long hash length");
        if(sizeof(catbuf) < (size_t) hblock + (size_t) hlen)
                Host_Error("Invalid hash function used for HMAC - too long hash block length");
        if(sizeof(catbuf) < (size_t) hblock + (size_t) n)
@@ -26,16 +28,16 @@ void hmac(
        if(k > hblock)
        {
                // hash the key if it is too long
-               // NO! that makes it too short if hblock != hlen
-               // just shorten it, then
-               // hfunc(hashbuf, key, k);
-               // key = hashbuf;
-               k = hblock;
+               hfunc(k_xor_opad, key, k);
+               key = k_xor_opad;
+               k = hlen;
        }
-       else if(k < hblock)
+
+       if(k < hblock)
        {
                // zero pad the key if it is too short
-               memcpy(k_xor_opad, key, k);
+               if(key != k_xor_opad)
+                       memcpy(k_xor_opad, key, k);
                for(i = k; i < hblock; ++i)
                        k_xor_opad[i] = 0;
                key = k_xor_opad;