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s4:ntlmssp Use common code for ntlmssp_sign.c

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The common code does not have a mem_ctx on ntlmssp_check_packet() and
ntlmssp_unseal_packet().

We do however need some internal working of the code exposed, so some
structures are moved to ntlmssp_sign.h

Andrew Bartlett
This commit is contained in:
Andrew Bartlett 2010-05-25 21:18:15 +10:00
parent 38a26f1073
commit fdc6db34ca
4 changed files with 21 additions and 526 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

19
libcli/auth/ntlmssp_private.h
View File

@ -20,6 +20,25 @@
/* For structures internal to the NTLMSSP implementation that should not be exposed */
#include "../lib/crypto/arcfour.h"
struct ntlmssp_crypt_direction {
uint32_t seq_num;
uint8_t sign_key[16];
struct arcfour_state seal_state;
};
union ntlmssp_crypt_state {
/* NTLM */
struct ntlmssp_crypt_direction ntlm;
/* NTLM2 */
struct {
struct ntlmssp_crypt_direction sending;
struct ntlmssp_crypt_direction receiving;
} ntlm2;
};
/* The following definitions come from libcli/auth/ntlmssp.c */
void debug_ntlmssp_flags(uint32_t neg_flags);

18
libcli/auth/ntlmssp_sign.c
View File

@ -22,7 +22,6 @@
#include "../libcli/auth/ntlmssp.h"
#include "../libcli/auth/libcli_auth.h"
#include "../lib/crypto/md5.h"
#include "../lib/crypto/arcfour.h"
#include "../lib/crypto/hmacmd5.h"
#include "../lib/crypto/crc32.h"
#include "../libcli/auth/ntlmssp_private.h"
@ -64,23 +63,6 @@ enum ntlmssp_direction {
NTLMSSP_RECEIVE
};
struct ntlmssp_crypt_direction {
uint32_t seq_num;
uint8_t sign_key[16];
struct arcfour_state seal_state;
};
union ntlmssp_crypt_state {
/* NTLM */
struct ntlmssp_crypt_direction ntlm;
/* NTLM2 */
struct {
struct ntlmssp_crypt_direction sending;
struct ntlmssp_crypt_direction receiving;
} ntlm2;
};
static NTSTATUS ntlmssp_make_packet_signature(struct ntlmssp_state *ntlmssp_state,
TALLOC_CTX *sig_mem_ctx,
const uint8_t *data, size_t length,

508
source4/auth/ntlmssp/ntlmssp_sign.c
View File

@ -21,512 +21,8 @@
#include "includes.h"
#include "auth/ntlmssp/ntlmssp.h"
#include "../libcli/auth/libcli_auth.h"
#include "../lib/crypto/crypto.h"
#include "auth/gensec/gensec.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"
/**
* Some notes on the NTLM2 code:
*
* NTLM2 is a AEAD system. This means that the data encrypted is not
* all the data that is signed. In DCE-RPC case, the headers of the
* DCE-RPC packets are also signed. This prevents some of the
* fun-and-games one might have by changing them.
*
*/
static void dump_arc4_state(const char *description,
struct arcfour_state *state)
{
dump_data_pw(description, state->sbox, sizeof(state->sbox));
}
static void calc_ntlmv2_key(uint8_t subkey[16],
DATA_BLOB session_key,
const char *constant)
{
struct MD5Context ctx3;
MD5Init(&ctx3);
MD5Update(&ctx3, session_key.data, session_key.length);
MD5Update(&ctx3, (const uint8_t *)constant, strlen(constant)+1);
MD5Final(subkey, &ctx3);
}
enum ntlmssp_direction {
NTLMSSP_SEND,
NTLMSSP_RECEIVE
};
struct ntlmssp_crypt_direction {
uint32_t seq_num;
uint8_t sign_key[16];
struct arcfour_state seal_state;
};
union ntlmssp_crypt_state {
/* NTLM */
struct ntlmssp_crypt_direction ntlm;
/* NTLM2 */
struct {
struct ntlmssp_crypt_direction sending;
struct ntlmssp_crypt_direction receiving;
} ntlm2;
};
static NTSTATUS ntlmssp_make_packet_signature(struct ntlmssp_state *ntlmssp_state,
TALLOC_CTX *sig_mem_ctx,
const uint8_t *data, size_t length,
const uint8_t *whole_pdu, size_t pdu_length,
enum ntlmssp_direction direction,
DATA_BLOB *sig, bool encrypt_sig)
{
if (ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_NTLM2) {
HMACMD5Context ctx;
uint8_t digest[16];
uint8_t seq_num[4];
*sig = data_blob_talloc(sig_mem_ctx, NULL, NTLMSSP_SIG_SIZE);
if (!sig->data) {
return NT_STATUS_NO_MEMORY;
}
switch (direction) {
case NTLMSSP_SEND:
SIVAL(seq_num, 0, ntlmssp_state->crypt->ntlm2.sending.seq_num);
ntlmssp_state->crypt->ntlm2.sending.seq_num++;
hmac_md5_init_limK_to_64(ntlmssp_state->crypt->ntlm2.sending.sign_key, 16, &ctx);
break;
case NTLMSSP_RECEIVE:
SIVAL(seq_num, 0, ntlmssp_state->crypt->ntlm2.receiving.seq_num);
ntlmssp_state->crypt->ntlm2.receiving.seq_num++;
hmac_md5_init_limK_to_64(ntlmssp_state->crypt->ntlm2.receiving.sign_key, 16, &ctx);
break;
}
hmac_md5_update(seq_num, sizeof(seq_num), &ctx);
hmac_md5_update(whole_pdu, pdu_length, &ctx);
hmac_md5_final(digest, &ctx);
if (encrypt_sig && (ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_KEY_EXCH)) {
switch (direction) {
case NTLMSSP_SEND:
arcfour_crypt_sbox(&ntlmssp_state->crypt->ntlm2.sending.seal_state,
digest, 8);
break;
case NTLMSSP_RECEIVE:
arcfour_crypt_sbox(&ntlmssp_state->crypt->ntlm2.receiving.seal_state,
digest, 8);
break;
}
}
SIVAL(sig->data, 0, NTLMSSP_SIGN_VERSION);
memcpy(sig->data + 4, digest, 8);
memcpy(sig->data + 12, seq_num, 4);
DEBUG(10,("NTLM2: created signature over %llu bytes of input:\n",
(unsigned long long)pdu_length));
dump_data(11, sig->data, sig->length);
} else {
bool ok;
uint32_t crc;
crc = crc32_calc_buffer(data, length);
ok = msrpc_gen(sig_mem_ctx,
sig, "dddd",
NTLMSSP_SIGN_VERSION, 0, crc,
ntlmssp_state->crypt->ntlm.seq_num);
if (!ok) {
return NT_STATUS_NO_MEMORY;
}
ntlmssp_state->crypt->ntlm.seq_num++;
arcfour_crypt_sbox(&ntlmssp_state->crypt->ntlm.seal_state,
sig->data+4, sig->length-4);
DEBUG(10,("NTLM1: created signature over %llu bytes of input:\n",
(unsigned long long)length));
dump_data(11, sig->data, sig->length);
}
return NT_STATUS_OK;
}
NTSTATUS ntlmssp_sign_packet(struct ntlmssp_state *ntlmssp_state,
TALLOC_CTX *sig_mem_ctx,
const uint8_t *data, size_t length,
const uint8_t *whole_pdu, size_t pdu_length,
DATA_BLOB *sig)
{
NTSTATUS nt_status;
nt_status = ntlmssp_make_packet_signature(ntlmssp_state,
sig_mem_ctx,
data, length,
whole_pdu, pdu_length,
NTLMSSP_SEND, sig, true);
return nt_status;
}
/**
* Check the signature of an incoming packet
*
*/
NTSTATUS ntlmssp_check_packet(struct ntlmssp_state *ntlmssp_state,
TALLOC_CTX *sig_mem_ctx,
const uint8_t *data, size_t length,
const uint8_t *whole_pdu, size_t pdu_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;
}
nt_status = ntlmssp_make_packet_signature(ntlmssp_state,
sig_mem_ctx,
data, length,
whole_pdu, pdu_length,
NTLMSSP_RECEIVE,
&local_sig, true);
if (!NT_STATUS_IS_OK(nt_status)) {
DEBUG(0,("NTLMSSP packet sig creation failed with %s\n",
nt_errstr(nt_status)));
return nt_status;
}
if (ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_NTLM2) {
if (local_sig.length != sig->length ||
memcmp(local_sig.data, sig->data, sig->length) != 0) {
DEBUG(10,("BAD SIG NTLM2: wanted signature over %llu bytes of input:\n",
(unsigned long long)pdu_length));
dump_data(10, local_sig.data, local_sig.length);
DEBUG(10,("BAD SIG: got signature over %llu bytes of input:\n",
(unsigned long long)pdu_length));
dump_data(10, sig->data, sig->length);
data_blob_free(&local_sig);
return NT_STATUS_ACCESS_DENIED;
}
} else {
if (local_sig.length != sig->length ||
memcmp(local_sig.data + 8, sig->data + 8, sig->length - 8) != 0) {
DEBUG(10,("BAD SIG NTLM1: wanted signature of %llu bytes of input:\n",
(unsigned long long)length));
dump_data(5, local_sig.data, local_sig.length);
DEBUG(10,("BAD SIG: got signature of %llu bytes of input:\n",
(unsigned long long)length));
dump_data(10, sig->data, sig->length);
data_blob_free(&local_sig);
return NT_STATUS_ACCESS_DENIED;
}
}
dump_data_pw("checked ntlmssp signature\n", sig->data, sig->length);
data_blob_free(&local_sig);
return NT_STATUS_OK;
}
/**
* Seal data with the NTLMSSP algorithm
*
*/
NTSTATUS ntlmssp_seal_packet(struct ntlmssp_state *ntlmssp_state,
TALLOC_CTX *sig_mem_ctx,
uint8_t *data, size_t length,
const uint8_t *whole_pdu, size_t pdu_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) {
NTSTATUS nt_status;
/*
* The order of these two operations matters - we
* must first seal the packet, then seal the
* sequence number - this is because the
* send_seal_hash is not constant, but is is rather
* updated with each iteration
*/
nt_status = ntlmssp_make_packet_signature(ntlmssp_state,
sig_mem_ctx,
data, length,
whole_pdu, pdu_length,
NTLMSSP_SEND,
sig, false);
if (!NT_STATUS_IS_OK(nt_status)) {
return nt_status;
}
arcfour_crypt_sbox(&ntlmssp_state->crypt->ntlm2.sending.seal_state,
data, length);
if (ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_KEY_EXCH) {
arcfour_crypt_sbox(&ntlmssp_state->crypt->ntlm2.sending.seal_state,
sig->data+4, 8);
}
} else {
bool ok;
uint32_t crc;
crc = crc32_calc_buffer(data, length);
ok = msrpc_gen(sig_mem_ctx,
sig, "dddd",
NTLMSSP_SIGN_VERSION, 0, crc,
ntlmssp_state->crypt->ntlm.seq_num);
if (!ok) {
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 because the ntlmv1_arc4_state
* is not constant, but is is rather updated with
* each iteration
*/
arcfour_crypt_sbox(&ntlmssp_state->crypt->ntlm.seal_state,
data, length);
arcfour_crypt_sbox(&ntlmssp_state->crypt->ntlm.seal_state,
sig->data+4, sig->length-4);
ntlmssp_state->crypt->ntlm.seq_num++;
}
dump_data_pw("ntlmssp signature\n", sig->data, sig->length);
dump_data_pw("ntlmssp sealed data\n", data, length);
return NT_STATUS_OK;
}
/**
* Unseal data with the NTLMSSP algorithm
*
*/
NTSTATUS ntlmssp_unseal_packet(struct ntlmssp_state *ntlmssp_state,
TALLOC_CTX *sig_mem_ctx,
uint8_t *data, size_t length,
const uint8_t *whole_pdu, size_t pdu_length,
const DATA_BLOB *sig)
{
NTSTATUS status;
if (!ntlmssp_state->session_key.length) {
DEBUG(3, ("NO session key, cannot unseal packet\n"));
return NT_STATUS_NO_USER_SESSION_KEY;
}
dump_data_pw("ntlmssp sealed data\n", data, length);
if (ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_NTLM2) {
arcfour_crypt_sbox(&ntlmssp_state->crypt->ntlm2.receiving.seal_state,
data, length);
} else {
arcfour_crypt_sbox(&ntlmssp_state->crypt->ntlm.seal_state,
data, length);
}
dump_data_pw("ntlmssp clear data\n", data, length);
status = ntlmssp_check_packet(ntlmssp_state,
sig_mem_ctx,
data, length,
whole_pdu, pdu_length,
sig);
if (!NT_STATUS_IS_OK(status)) {
DEBUG(1,("NTLMSSP packet check for unseal failed due to invalid signature on %llu bytes of input:\n",
(unsigned long long)length));
}
return status;
}
/**
Initialise the state for NTLMSSP signing.
*/
NTSTATUS ntlmssp_sign_init(struct ntlmssp_state *ntlmssp_state)
{
DEBUG(3, ("NTLMSSP Sign/Seal - Initialising with flags:\n"));
debug_ntlmssp_flags(ntlmssp_state->neg_flags);
if (ntlmssp_state->session_key.length < 8) {
DEBUG(3, ("NO session key, cannot intialise signing\n"));
return NT_STATUS_NO_USER_SESSION_KEY;
}
ntlmssp_state->crypt = talloc_zero(ntlmssp_state,
union ntlmssp_crypt_state);
if (ntlmssp_state->crypt == NULL) {
return NT_STATUS_NO_MEMORY;
}
if (ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_NTLM2) {
DATA_BLOB weak_session_key = ntlmssp_state->session_key;
const char *send_sign_const;
const char *send_seal_const;
const char *recv_sign_const;
const char *recv_seal_const;
uint8_t send_seal_key[16];
DATA_BLOB send_seal_blob = data_blob_const(send_seal_key,
sizeof(send_seal_key));
uint8_t recv_seal_key[16];
DATA_BLOB recv_seal_blob = data_blob_const(recv_seal_key,
sizeof(recv_seal_key));
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:
return NT_STATUS_INTERNAL_ERROR;
}
/*
* Weaken NTLMSSP keys to cope with down-level
* clients, servers and export restrictions.
*
* We probably should have some parameters to
* control this, once we get NTLM2 working.
*
* Key weakening was not performed on the master key
* for NTLM2, but must be done on the encryption subkeys only.
*/
if (ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_128) {
/* nothing to do */
} else if (ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_56) {
weak_session_key.length = 7;
} else { /* forty bits */
weak_session_key.length = 5;
}
dump_data_pw("NTLMSSP weakend master key:\n",
weak_session_key.data,
weak_session_key.length);
/* SEND: sign key */
calc_ntlmv2_key(ntlmssp_state->crypt->ntlm2.sending.sign_key,
ntlmssp_state->session_key, send_sign_const);
dump_data_pw("NTLMSSP send sign key:\n",
ntlmssp_state->crypt->ntlm2.sending.sign_key, 16);
/* SEND: seal ARCFOUR pad */
calc_ntlmv2_key(send_seal_key,
weak_session_key, send_seal_const);
dump_data_pw("NTLMSSP send seal key:\n", send_seal_key, 16);
arcfour_init(&ntlmssp_state->crypt->ntlm2.sending.seal_state,
&send_seal_blob);
dump_arc4_state("NTLMSSP send seal arc4 state:\n",
&ntlmssp_state->crypt->ntlm2.sending.seal_state);
/* SEND: seq num */
ntlmssp_state->crypt->ntlm2.sending.seq_num = 0;
/* RECV: sign key */
calc_ntlmv2_key(ntlmssp_state->crypt->ntlm2.receiving.sign_key,
ntlmssp_state->session_key, recv_sign_const);
dump_data_pw("NTLMSSP recv sign key:\n",
ntlmssp_state->crypt->ntlm2.receiving.sign_key, 16);
/* RECV: seal ARCFOUR pad */
calc_ntlmv2_key(recv_seal_key,
weak_session_key, recv_seal_const);
dump_data_pw("NTLMSSP recv seal key:\n", recv_seal_key, 16);
arcfour_init(&ntlmssp_state->crypt->ntlm2.receiving.seal_state,
&recv_seal_blob);
dump_arc4_state("NTLMSSP recv seal arc4 state:\n",
&ntlmssp_state->crypt->ntlm2.receiving.seal_state);
/* RECV: seq num */
ntlmssp_state->crypt->ntlm2.receiving.seq_num = 0;
} else {
uint8_t weak_session_key[8];
DATA_BLOB seal_session_key = ntlmssp_state->session_key;
bool do_weak = false;
DEBUG(5, ("NTLMSSP Sign/Seal - using NTLM1\n"));
/*
* Key weakening not performed on the master key for NTLM2
* and does not occour for NTLM1. Therefore we only need
* to do this for the LM_KEY.
*/
if (ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_LM_KEY) {
do_weak = true;
}
/*
* Nothing to weaken.
* We certainly don't want to 'extend' the length...
*/
if (seal_session_key.length < 16) {
/* TODO: is this really correct? */
do_weak = false;
}
if (do_weak) {
memcpy(weak_session_key, seal_session_key.data, 8);
seal_session_key = data_blob_const(weak_session_key, 8);
/*
* LM key doesn't support 128 bit crypto, so this is
* the best we can do. If you negotiate 128 bit, but
* not 56, you end up with 40 bit...
*/
if (ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_56) {
weak_session_key[7] = 0xa0;
} else { /* forty bits */
weak_session_key[5] = 0xe5;
weak_session_key[6] = 0x38;
weak_session_key[7] = 0xb0;
}
}
arcfour_init(&ntlmssp_state->crypt->ntlm.seal_state,
&seal_session_key);
dump_arc4_state("NTLMv1 arc4 state:\n",
&ntlmssp_state->crypt->ntlm.seal_state);
ntlmssp_state->crypt->ntlm.seq_num = 0;
}
return NT_STATUS_OK;
}
#include "../libcli/auth/ntlmssp_private.h"
NTSTATUS gensec_ntlmssp_sign_packet(struct gensec_security *gensec_security,
TALLOC_CTX *sig_mem_ctx,
@ -560,7 +56,6 @@ NTSTATUS gensec_ntlmssp_check_packet(struct gensec_security *gensec_security,
NTSTATUS nt_status;
nt_status = ntlmssp_check_packet(gensec_ntlmssp->ntlmssp_state,
sig_mem_ctx,
data, length,
whole_pdu, pdu_length,
sig);
@ -603,7 +98,6 @@ NTSTATUS gensec_ntlmssp_unseal_packet(struct gensec_security *gensec_security,
NTSTATUS nt_status;
nt_status = ntlmssp_unseal_packet(gensec_ntlmssp->ntlmssp_state,
sig_mem_ctx,
data, length,
whole_pdu, pdu_length,
sig);

2
source4/auth/ntlmssp/wscript_build
View File

@ -1,7 +1,7 @@
#!/usr/bin/env python
bld.SAMBA_MODULE('gensec_ntlmssp',
source='ntlmssp.c ntlmssp_sign.c ntlmssp_client.c ntlmssp_server.c',
source='ntlmssp.c ntlmssp_sign.c ../../../libcli/auth/ntlmssp_sign.c ntlmssp_client.c ntlmssp_server.c',
autoproto='proto.h',
subsystem='gensec',
init_function='gensec_ntlmssp_init',