1 files changed, 91 insertions, 0 deletions
diff --git a/source4/lib/crypto/hmacsha256.c b/source4/lib/crypto/hmacsha256.c
new file mode 100644
index 0000000000..6b0af9ee83
--- /dev/null
+++ b/source4/lib/crypto/hmacsha256.c
@@ -0,0 +1,91 @@
+/* 
+   Unix SMB/CIFS implementation.
+
+   Interface header:    HMAC SHA-256 code
+
+   Copyright (C) Andrew Tridgell 2008
+
+   based in hmacsha1.c which is:
+     Copyright (C) Stefan Metzmacher
+   
+   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 3 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, see <http://www.gnu.org/licenses/>.
+*/
+
+/*
+ taken direct from rfc2202 implementation and modified for suitable use
+ */
+
+#include "includes.h"
+#include "lib/crypto/crypto.h"
+
+/***********************************************************************
+ the rfc 2104/2202 version of hmac_sha256 initialisation.
+***********************************************************************/
+_PUBLIC_ void hmac_sha256_init(const uint8_t *key, size_t key_len, struct HMACSHA256Context *ctx)
+{
+        int i;
+	uint8_t tk[SHA256_DIGEST_LENGTH];
+
+        /* if key is longer than 64 bytes reset it to key=HASH(key) */
+        if (key_len > 64)
+	{
+                SHA256_CTX tctx;
+
+                SHA256_Init(&tctx);
+                SHA256_Update(&tctx, key, key_len);
+                SHA256_Final(tk, &tctx);
+
+                key = tk;
+                key_len = SHA256_DIGEST_LENGTH;
+        }
+
+        /* start out by storing key in pads */
+        ZERO_STRUCT(ctx->k_ipad);
+        ZERO_STRUCT(ctx->k_opad);
+        memcpy( ctx->k_ipad, key, key_len);
+        memcpy( ctx->k_opad, key, 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;
+        }
+
+        SHA256_Init(&ctx->ctx);
+        SHA256_Update(&ctx->ctx, ctx->k_ipad, 64);  
+}
+
+/***********************************************************************
+ update hmac_sha256 "inner" buffer
+***********************************************************************/
+_PUBLIC_ void hmac_sha256_update(const uint8_t *data, size_t data_len, struct HMACSHA256Context *ctx)
+{
+        SHA256_Update(&ctx->ctx, data, data_len); /* then text of datagram */
+}
+
+/***********************************************************************
+ finish off hmac_sha256 "inner" buffer and generate outer one.
+***********************************************************************/
+_PUBLIC_ void hmac_sha256_final(uint8_t digest[SHA256_DIGEST_LENGTH], struct HMACSHA256Context *ctx)
+{
+        SHA256_CTX ctx_o;
+
+        SHA256_Final(digest, &ctx->ctx);
+
+        SHA256_Init(&ctx_o);
+        SHA256_Update(&ctx_o, ctx->k_opad, 64);
+        SHA256_Update(&ctx_o, digest, SHA256_DIGEST_LENGTH);
+        SHA256_Final(digest, &ctx_o);
+}