r3294: Fix for SMB signing with 56-bit DES session keys. From Nalin Dahyabhai <nalin...

Jeremy.

diff --git a/source/libsmb/smb_signing.c b/source/libsmb/smb_signing.c
index 39131debf5edbfa04960efd5ea2b080a937fbd93..b02a13c73e12f73738023c04da787a0696dad441 100644 (file)
--- a/source/libsmb/smb_signing.c
+++ b/source/libsmb/smb_signing.c
@@ -255,6 +255,7 @@ static void simple_packet_signature(struct smb_basic_signing_context *data,
        const size_t offset_end_of_sig = (smb_ss_field + 8);
        unsigned char sequence_buf[8];
        struct MD5Context md5_ctx;
+       unsigned char key_buf[16];
 
        /*
         * Firstly put the sequence number into the first 4 bytes.
@@ -276,8 +277,14 @@ static void simple_packet_signature(struct smb_basic_signing_context *data,
        MD5Init(&md5_ctx);
 
        /* intialise with the key */
-       MD5Update(&md5_ctx, data->mac_key.data, 
-                 data->mac_key.length); 
+       /* NB. When making and verifying SMB signatures, Windows apparently
+               zero-pads the key to 128 bits if it isn't long enough.
+               From Nalin Dahyabhai <nalin@redhat.com> */
+       MD5Update(&md5_ctx, data->mac_key.data, data->mac_key.length); 
+       if (data->mac_key.length < sizeof(key_buf)) {
+               memset(key_buf, 0, sizeof(key_buf));
+               MD5Update(&md5_ctx, key_buf, sizeof(key_buf) - data->mac_key.length);
+       }
 
        /* copy in the first bit of the SMB header */
        MD5Update(&md5_ctx, buf + 4, smb_ss_field - 4);