Add backend encryption support for NTLMv2.

The leg-work for this was done by the folks at samba-tng.org, I'm just bringing
it accross to HEAD.

The MD5 implementation is seperatly derived, and does not have the copyright
problems that the one in TNG has.

Also add const to a few places where it makes sence.

Andrew Bartlett
(This used to be commit 8df8e841445dfe09fc7a06bb55d12adc3fecb345)

1 files changed, 136 insertions, 0 deletions

diff --git a/source3/lib/hmacmd5.c b/source3/lib/hmacmd5.c
new file mode 100644
index 00000000000..1d9b89e0cce
--- /dev/null
+++ b/source3/lib/hmacmd5.c
@@ -0,0 +1,136 @@
+/* 
+   Unix SMB/Netbios implementation.
+   Version 1.9.
+   HMAC MD5 code for use in NTLMv2
+   Copyright (C) Luke Kenneth Casson Leighton 1996-2000
+   Copyright (C) Andrew Tridgell 1992-2000
+   
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2 of the License, or
+   (at your option) any later version.
+   
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+   
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software
+   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+*/
+
+/* taken direct from rfc2104 implementation and modified for suitable use
+ * for ntlmv2.
+ */
+
+#include "includes.h"
+
+/***********************************************************************
+ the rfc 2104 version of hmac_md5 initialisation.
+***********************************************************************/
+void hmac_md5_init_rfc2104(uchar*  key, int key_len, HMACMD5Context *ctx)
+{
+        int i;
+
+        /* if key is longer than 64 bytes reset it to key=MD5(key) */
+        if (key_len > 64)
+	{
+		uchar tk[16];
+                struct MD5Context tctx;
+
+                MD5Init(&tctx);
+                MD5Update(&tctx, key, key_len);
+                MD5Final(tk, &tctx);
+
+                key = tk;
+                key_len = 16;
+        }
+
+        /* start out by storing key in pads */
+        ZERO_STRUCT(ctx->k_ipad);
+        ZERO_STRUCT(ctx->k_opad);
+        bcopy( key, ctx->k_ipad, key_len);
+        bcopy( key, ctx->k_opad, key_len);
+
+        /* XOR key with ipad and opad values */
+        for (i=0; i<64; i++)
+	{
+                ctx->k_ipad[i] ^= 0x36;
+                ctx->k_opad[i] ^= 0x5c;
+        }
+
+        MD5Init(&ctx->ctx);
+        MD5Update(&ctx->ctx, ctx->k_ipad, 64);  
+}
+
+/***********************************************************************
+ the microsoft version of hmac_md5 initialisation.
+***********************************************************************/
+void hmac_md5_init_limK_to_64(const uchar* key, int key_len,
+			HMACMD5Context *ctx)
+{
+        int i;
+
+        /* if key is longer than 64 bytes truncate it */
+        if (key_len > 64)
+	{
+                key_len = 64;
+        }
+
+        /* start out by storing key in pads */
+        ZERO_STRUCT(ctx->k_ipad);
+        ZERO_STRUCT(ctx->k_opad);
+        bcopy( key, ctx->k_ipad, key_len);
+        bcopy( key, ctx->k_opad, key_len);
+
+        /* XOR key with ipad and opad values */
+        for (i=0; i<64; i++)
+	{
+                ctx->k_ipad[i] ^= 0x36;
+                ctx->k_opad[i] ^= 0x5c;
+        }
+
+        MD5Init(&ctx->ctx);
+        MD5Update(&ctx->ctx, ctx->k_ipad, 64);  
+}
+
+/***********************************************************************
+ update hmac_md5 "inner" buffer
+***********************************************************************/
+void hmac_md5_update(const uchar* text, int text_len, HMACMD5Context *ctx)
+{
+        MD5Update(&ctx->ctx, text, text_len); /* then text of datagram */
+}
+
+/***********************************************************************
+ finish off hmac_md5 "inner" buffer and generate outer one.
+***********************************************************************/
+void hmac_md5_final(uchar *digest, HMACMD5Context *ctx)
+
+{
+        struct MD5Context ctx_o;
+
+        MD5Final(digest, &ctx->ctx);          
+
+        MD5Init(&ctx_o);
+        MD5Update(&ctx_o, ctx->k_opad, 64);   
+        MD5Update(&ctx_o, digest, 16); 
+        MD5Final(digest, &ctx_o);
+}
+
+/***********************************************************
+ single function to calculate an HMAC MD5 digest from data.
+ use the microsoft hmacmd5 init method because the key is 16 bytes.
+************************************************************/
+void hmac_md5( uchar key[16], uchar* data, int data_len, uchar* digest)
+{
+	HMACMD5Context ctx;
+	hmac_md5_init_limK_to_64(key, 16, &ctx);
+	if (data_len != 0)
+	{
+		hmac_md5_update(data, data_len, &ctx);
+	}
+	hmac_md5_final(digest, &ctx);
+}
+