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/*
* Unix SMB/CIFS implementation.
* Version 3.0
* NTLMSSP Signing routines
* Copyright (C) Luke Kenneth Casson Leighton 1996-2001
* Copyright (C) Andrew Bartlett 2003
*
* 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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*/
#include "includes.h"
#define CLI_SIGN "session key to client-to-server signing key magic constant"
#define CLI_SEAL "session key to client-to-server sealing key magic constant"
#define SRV_SIGN "session key to server-to-client signing key magic constant"
#define SRV_SEAL "session key to server-to-client sealing key magic constant"
static void NTLMSSPcalc_ap( unsigned char *hash, unsigned char *data, int len)
{
unsigned char index_i = hash[256];
unsigned char index_j = hash[257];
int ind;
for (ind = 0; ind < len; ind++)
{
unsigned char tc;
unsigned char t;
index_i++;
index_j += hash[index_i];
tc = hash[index_i];
hash[index_i] = hash[index_j];
hash[index_j] = tc;
t = hash[index_i] + hash[index_j];
data[ind] = data[ind] ^ hash[t];
}
hash[256] = index_i;
hash[257] = index_j;
}
static void calc_hash(unsigned char *hash, const char *k2, int k2l)
{
unsigned char j = 0;
int ind;
for (ind = 0; ind < 256; ind++)
{
hash[ind] = (unsigned char)ind;
}
for (ind = 0; ind < 256; ind++)
{
unsigned char tc;
j += (hash[ind] + k2[ind%k2l]);
tc = hash[ind];
hash[ind] = hash[j];
hash[j] = tc;
}
hash[256] = 0;
hash[257] = 0;
}
static void calc_ntlmv2_hash(unsigned char hash[16], char digest[16],
const char encrypted_response[16],
const char *constant)
{
struct MD5Context ctx3;
MD5Init(&ctx3);
MD5Update(&ctx3, encrypted_response, 5);
MD5Update(&ctx3, constant, strlen(constant));
MD5Final(digest, &ctx3);
calc_hash(hash, digest, 16);
}
static NTSTATUS ntlmssp_make_packet_signiture(NTLMSSP_CLIENT_STATE *ntlmssp_state,
const uchar *data, size_t length,
DATA_BLOB *sig)
{
if (ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_NTLM2) {
HMACMD5Context ctx;
char seq_num[4];
uchar digest[16];
SIVAL(seq_num, 0, &ntlmssp_state->ntlmssp_seq_num);
hmac_md5_init_limK_to_64(ntlmssp_state->cli_sign_const, 16, &ctx);
hmac_md5_update(seq_num, 4, &ctx);
hmac_md5_update(data, length, &ctx);
hmac_md5_final(digest, &ctx);
if (!msrpc_gen(sig, "Bd", digest, sizeof(digest), ntlmssp_state->ntlmssp_seq_num)) {
return NT_STATUS_NO_MEMORY;
}
NTLMSSPcalc_ap(ntlmssp_state->cli_seal_hash, sig->data, sig->length);
} else {
uint32 crc;
crc = crc32_calc_buffer(data, length);
if (!msrpc_gen(sig, "ddd", 0, crc, ntlmssp_state->ntlmssp_seq_num)) {
return NT_STATUS_NO_MEMORY;
}
NTLMSSPcalc_ap(ntlmssp_state->ntlmssp_hash, sig->data, sig->length);
}
return NT_STATUS_OK;
}
NTSTATUS ntlmssp_client_sign_packet(NTLMSSP_CLIENT_STATE *ntlmssp_state,
const uchar *data, size_t length,
DATA_BLOB *sig)
{
ntlmssp_state->ntlmssp_seq_num++;
return ntlmssp_make_packet_signiture(ntlmssp_state, data, length, sig);
}
/**
* Check the signature of an incoming packet
* @note caller *must* check that the signature is the size it expects
*
*/
NTSTATUS ntlmssp_client_check_packet(NTLMSSP_CLIENT_STATE *ntlmssp_state,
const uchar *data, size_t length,
const DATA_BLOB *sig)
{
DATA_BLOB local_sig;
NTSTATUS nt_status;
if (sig->length < 8) {
DEBUG(0, ("NTLMSSP packet check failed due to short signiture (%u bytes)!\n",
sig->length));
}
nt_status = ntlmssp_make_packet_signiture(ntlmssp_state, data,
length, &local_sig);
if (!NT_STATUS_IS_OK(nt_status)) {
DEBUG(0, ("NTLMSSP packet check failed with %s\n", nt_errstr(nt_status)));
return nt_status;
}
if (memcmp(sig->data, local_sig.data, MIN(sig->length, local_sig.length)) == 0) {
return NT_STATUS_OK;
} else {
DEBUG(0, ("NTLMSSP packet check failed due to invalid signiture!\n"));
return NT_STATUS_ACCESS_DENIED;
}
}
/**
Initialise the state for NTLMSSP signing.
*/
NTSTATUS ntlmssp_client_sign_init(NTLMSSP_CLIENT_STATE *ntlmssp_state)
{
unsigned char p24[24];
unsigned char lm_hash[16];
if (!ntlmssp_state->lm_resp.data) {
/* can't sign or check signitures yet */
return NT_STATUS_UNSUCCESSFUL;
}
E_deshash(ntlmssp_state->password, lm_hash);
NTLMSSPOWFencrypt(lm_hash, ntlmssp_state->lm_resp.data, p24);
if (ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_NTLM2)
{
calc_ntlmv2_hash(ntlmssp_state->cli_sign_hash, ntlmssp_state->cli_sign_const, p24, CLI_SIGN);
calc_ntlmv2_hash(ntlmssp_state->cli_seal_hash, ntlmssp_state->cli_seal_const, p24, CLI_SEAL);
calc_ntlmv2_hash(ntlmssp_state->srv_sign_hash, ntlmssp_state->srv_sign_const, p24, SRV_SIGN);
calc_ntlmv2_hash(ntlmssp_state->srv_seal_hash, ntlmssp_state->srv_seal_const, p24, SRV_SEAL);
}
else
{
char k2[8];
memcpy(k2, p24, 5);
k2[5] = 0xe5;
k2[6] = 0x38;
k2[7] = 0xb0;
calc_hash(ntlmssp_state->ntlmssp_hash, k2, 8);
}
ntlmssp_state->ntlmssp_seq_num = 0;
ZERO_STRUCT(lm_hash);
return NT_STATUS_OK;
}
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