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samba-mirror/source3/libsmb/ntlmssp_sign.c
2007-10-10 10:55:40 -05:00

414 lines
12 KiB
C

/*
* 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[258], unsigned 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[258], unsigned char digest[16],
DATA_BLOB session_key,
const char *constant)
{
struct MD5Context ctx3;
/* NOTE: This code is currently complate fantasy - it's
got more in common with reality than the previous code
(the LM session key is not the right thing to use) but
it still needs work */
MD5Init(&ctx3);
MD5Update(&ctx3, session_key.data, session_key.length);
MD5Update(&ctx3, (const unsigned char *)constant, strlen(constant)+1);
MD5Final(digest, &ctx3);
calc_hash(hash, digest, 16);
}
enum ntlmssp_direction {
NTLMSSP_SEND,
NTLMSSP_RECEIVE
};
static NTSTATUS ntlmssp_make_packet_signature(NTLMSSP_STATE *ntlmssp_state,
const uchar *data, size_t length,
enum ntlmssp_direction direction,
DATA_BLOB *sig)
{
if (ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_NTLM2) {
HMACMD5Context ctx;
uchar seq_num[4];
uchar digest[16];
SIVAL(seq_num, 0, ntlmssp_state->ntlmssp_seq_num);
hmac_md5_init_limK_to_64((const unsigned char *)(ntlmssp_state->send_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, "dBd", NTLMSSP_SIGN_VERSION, digest, 8 /* only copy first 8 bytes */
, ntlmssp_state->ntlmssp_seq_num)) {
return NT_STATUS_NO_MEMORY;
}
if (ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_KEY_EXCH) {
switch (direction) {
case NTLMSSP_SEND:
NTLMSSPcalc_ap(ntlmssp_state->send_sign_hash, sig->data+4, sig->length-4);
break;
case NTLMSSP_RECEIVE:
NTLMSSPcalc_ap(ntlmssp_state->recv_sign_hash, sig->data+4, sig->length-4);
break;
}
}
} else {
uint32 crc;
crc = crc32_calc_buffer((const char *)data, length);
if (!msrpc_gen(sig, "dddd", NTLMSSP_SIGN_VERSION, 0, crc, ntlmssp_state->ntlmssp_seq_num)) {
return NT_STATUS_NO_MEMORY;
}
dump_data_pw("ntlmssp hash:\n", ntlmssp_state->ntlmssp_hash,
sizeof(ntlmssp_state->ntlmssp_hash));
NTLMSSPcalc_ap(ntlmssp_state->ntlmssp_hash, sig->data+4, sig->length-4);
}
return NT_STATUS_OK;
}
NTSTATUS ntlmssp_sign_packet(NTLMSSP_STATE *ntlmssp_state,
const uchar *data, size_t length,
DATA_BLOB *sig)
{
NTSTATUS nt_status;
if (!ntlmssp_state->session_key.length) {
DEBUG(3, ("NO session key, cannot check sign packet\n"));
return NT_STATUS_NO_USER_SESSION_KEY;
}
nt_status = ntlmssp_make_packet_signature(ntlmssp_state, data, length, NTLMSSP_SEND, sig);
/* increment counter on send */
ntlmssp_state->ntlmssp_seq_num++;
return nt_status;
}
/**
* Check the signature of an incoming packet
* @note caller *must* check that the signature is the size it expects
*
*/
NTSTATUS ntlmssp_check_packet(NTLMSSP_STATE *ntlmssp_state,
const uchar *data, size_t length,
const DATA_BLOB *sig)
{
DATA_BLOB local_sig;
NTSTATUS nt_status;
if (!ntlmssp_state->session_key.length) {
DEBUG(3, ("NO session key, cannot check packet signature\n"));
return NT_STATUS_NO_USER_SESSION_KEY;
}
if (sig->length < 8) {
DEBUG(0, ("NTLMSSP packet check failed due to short signature (%lu bytes)!\n",
(unsigned long)sig->length));
}
nt_status = ntlmssp_make_packet_signature(ntlmssp_state, data,
length, NTLMSSP_RECEIVE, &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+sig->length - 8, local_sig.data+local_sig.length - 8, 8) != 0) {
DEBUG(5, ("BAD SIG: wanted signature of\n"));
dump_data(5, (const char *)local_sig.data, local_sig.length);
DEBUG(5, ("BAD SIG: got signature of\n"));
dump_data(5, (const char *)(sig->data), sig->length);
DEBUG(0, ("NTLMSSP packet check failed due to invalid signature!\n"));
return NT_STATUS_ACCESS_DENIED;
}
/* increment counter on recieive */
ntlmssp_state->ntlmssp_seq_num++;
return NT_STATUS_OK;
}
/**
* Seal data with the NTLMSSP algorithm
*
*/
NTSTATUS ntlmssp_seal_packet(NTLMSSP_STATE *ntlmssp_state,
uchar *data, size_t length,
DATA_BLOB *sig)
{
if (!ntlmssp_state->session_key.length) {
DEBUG(3, ("NO session key, cannot seal packet\n"));
return NT_STATUS_NO_USER_SESSION_KEY;
}
DEBUG(10,("ntlmssp_seal_data: seal\n"));
dump_data_pw("ntlmssp clear data\n", data, length);
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((const unsigned char *)(ntlmssp_state->send_sign_const), 16, &ctx);
hmac_md5_update((const unsigned char *)seq_num, 4, &ctx);
hmac_md5_update(data, length, &ctx);
hmac_md5_final(digest, &ctx);
if (!msrpc_gen(sig, "dBd", NTLMSSP_SIGN_VERSION, digest, 8 /* only copy first 8 bytes */
, ntlmssp_state->ntlmssp_seq_num)) {
return NT_STATUS_NO_MEMORY;
}
dump_data_pw("ntlmssp client sealing hash:\n",
ntlmssp_state->send_seal_hash,
sizeof(ntlmssp_state->send_seal_hash));
NTLMSSPcalc_ap(ntlmssp_state->send_seal_hash, data, length);
dump_data_pw("ntlmssp client signing hash:\n",
ntlmssp_state->send_sign_hash,
sizeof(ntlmssp_state->send_sign_hash));
NTLMSSPcalc_ap(ntlmssp_state->send_sign_hash, sig->data+4, sig->length-4);
} else {
uint32 crc;
crc = crc32_calc_buffer((const char *)data, length);
if (!msrpc_gen(sig, "dddd", NTLMSSP_SIGN_VERSION, 0, crc, ntlmssp_state->ntlmssp_seq_num)) {
return NT_STATUS_NO_MEMORY;
}
/* The order of these two operations matters - we must first seal the packet,
then seal the sequence number - this is becouse the ntlmssp_hash is not
constant, but is is rather updated with each iteration */
dump_data_pw("ntlmssp hash:\n", ntlmssp_state->ntlmssp_hash,
sizeof(ntlmssp_state->ntlmssp_hash));
NTLMSSPcalc_ap(ntlmssp_state->ntlmssp_hash, data, length);
dump_data_pw("ntlmssp hash:\n", ntlmssp_state->ntlmssp_hash,
sizeof(ntlmssp_state->ntlmssp_hash));
NTLMSSPcalc_ap(ntlmssp_state->ntlmssp_hash, sig->data+4, sig->length-4);
}
dump_data_pw("ntlmssp sealed data\n", data, length);
/* increment counter on send */
ntlmssp_state->ntlmssp_seq_num++;
return NT_STATUS_OK;
}
/**
* Unseal data with the NTLMSSP algorithm
*
*/
NTSTATUS ntlmssp_unseal_packet(NTLMSSP_STATE *ntlmssp_state,
uchar *data, size_t length,
DATA_BLOB *sig)
{
if (!ntlmssp_state->session_key.length) {
DEBUG(3, ("NO session key, cannot unseal packet\n"));
return NT_STATUS_NO_USER_SESSION_KEY;
}
DEBUG(10,("ntlmssp__unseal_data: seal\n"));
dump_data_pw("ntlmssp sealed data\n", data, length);
if (ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_NTLM2) {
NTLMSSPcalc_ap(ntlmssp_state->recv_seal_hash, data, length);
} else {
dump_data_pw("ntlmssp hash:\n", ntlmssp_state->ntlmssp_hash,
sizeof(ntlmssp_state->ntlmssp_hash));
NTLMSSPcalc_ap(ntlmssp_state->ntlmssp_hash, data, length);
}
dump_data_pw("ntlmssp clear data\n", data, length);
return ntlmssp_check_packet(ntlmssp_state, data, length, sig);
}
/**
Initialise the state for NTLMSSP signing.
*/
NTSTATUS ntlmssp_sign_init(NTLMSSP_STATE *ntlmssp_state)
{
unsigned char p24[24];
ZERO_STRUCT(p24);
DEBUG(3, ("NTLMSSP Sign/Seal - Initialising with flags:\n"));
debug_ntlmssp_flags(ntlmssp_state->neg_flags);
if (!ntlmssp_state->session_key.length) {
DEBUG(3, ("NO session key, cannot intialise signing\n"));
return NT_STATUS_NO_USER_SESSION_KEY;
}
if (ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_NTLM2)
{
const char *send_sign_const;
const char *send_seal_const;
const char *recv_sign_const;
const char *recv_seal_const;
switch (ntlmssp_state->role) {
case NTLMSSP_CLIENT:
send_sign_const = CLI_SIGN;
send_seal_const = CLI_SEAL;
recv_sign_const = SRV_SIGN;
recv_seal_const = SRV_SEAL;
break;
case NTLMSSP_SERVER:
send_sign_const = SRV_SIGN;
send_seal_const = SRV_SEAL;
recv_sign_const = CLI_SIGN;
recv_seal_const = CLI_SEAL;
break;
default:
send_sign_const = "unknown role";
send_seal_const = "unknown role";
recv_sign_const = "unknown role";
recv_seal_const = "unknown role";
break;
}
calc_ntlmv2_hash(ntlmssp_state->send_sign_hash,
ntlmssp_state->send_sign_const,
ntlmssp_state->session_key, send_sign_const);
dump_data_pw("NTLMSSP send sign hash:\n",
ntlmssp_state->send_sign_hash,
sizeof(ntlmssp_state->send_sign_hash));
calc_ntlmv2_hash(ntlmssp_state->send_seal_hash,
ntlmssp_state->send_seal_const,
ntlmssp_state->session_key, send_seal_const);
dump_data_pw("NTLMSSP send sesl hash:\n",
ntlmssp_state->send_seal_hash,
sizeof(ntlmssp_state->send_seal_hash));
calc_ntlmv2_hash(ntlmssp_state->recv_sign_hash,
ntlmssp_state->recv_sign_const,
ntlmssp_state->session_key, recv_sign_const);
dump_data_pw("NTLMSSP receive sign hash:\n",
ntlmssp_state->recv_sign_hash,
sizeof(ntlmssp_state->recv_sign_hash));
calc_ntlmv2_hash(ntlmssp_state->recv_seal_hash,
ntlmssp_state->recv_seal_const,
ntlmssp_state->session_key, recv_seal_const);
dump_data_pw("NTLMSSP receive seal hash:\n",
ntlmssp_state->recv_sign_hash,
sizeof(ntlmssp_state->recv_sign_hash));
}
else if (ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_LM_KEY) {
if (!ntlmssp_state->session_key.data || ntlmssp_state->session_key.length < 8) {
/* can't sign or check signatures yet */
DEBUG(5, ("NTLMSSP Sign/Seal - cannot use LM KEY yet\n"));
return NT_STATUS_UNSUCCESSFUL;
}
DEBUG(5, ("NTLMSSP Sign/Seal - using LM KEY\n"));
calc_hash(ntlmssp_state->ntlmssp_hash, ntlmssp_state->session_key.data, 8);
dump_data_pw("NTLMSSP hash:\n", ntlmssp_state->ntlmssp_hash,
sizeof(ntlmssp_state->ntlmssp_hash));
} else {
if (!ntlmssp_state->session_key.data || ntlmssp_state->session_key.length < 16) {
/* can't sign or check signatures yet */
DEBUG(5, ("NTLMSSP Sign/Seal - cannot use NT KEY yet\n"));
return NT_STATUS_UNSUCCESSFUL;
}
DEBUG(5, ("NTLMSSP Sign/Seal - using NT KEY\n"));
calc_hash(ntlmssp_state->ntlmssp_hash, ntlmssp_state->session_key.data, 16);
dump_data_pw("NTLMSSP hash:\n", ntlmssp_state->ntlmssp_hash,
sizeof(ntlmssp_state->ntlmssp_hash));
}
ntlmssp_state->ntlmssp_seq_num = 0;
return NT_STATUS_OK;
}