/* Unix SMB/CIFS implementation. 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 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 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(const unsigned char *key, int key_len, HMACMD5Context *ctx) { int i; unsigned char tk[16]; /* if key is longer than 64 bytes reset it to key=MD5(key) */ if (key_len > 64) { 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); 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; } 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 unsigned char* 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); 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; } MD5Init(&ctx->ctx); MD5Update(&ctx->ctx, ctx->k_ipad, 64); } /*********************************************************************** update hmac_md5 "inner" buffer ***********************************************************************/ void hmac_md5_update(const unsigned char *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(unsigned char *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( unsigned char key[16], const unsigned char *data, int data_len, unsigned char *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); }