--- /dev/null
+/*
+ * Unix SMB/CIFS implementation.
+ * Version 3.0
+ * NTLMSSP Signing routines
+ * Copyright (C) Andrew Bartlett 2003-2005
+ *
+ * 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/>.
+ */
+
+#include "includes.h"
+#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"
+
+#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:
+ DEBUG(100,("ntlmssp_make_packet_signature: SEND seq = %u, len = %u, pdu_len = %u\n",
+ ntlmssp_state->crypt->ntlm2.sending.seq_num,
+ (unsigned int)length,
+ (unsigned int)pdu_length));
+
+ 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:
+
+ DEBUG(100,("ntlmssp_make_packet_signature: RECV seq = %u, len = %u, pdu_len = %u\n",
+ ntlmssp_state->crypt->ntlm2.receiving.seq_num,
+ (unsigned int)length,
+ (unsigned int)pdu_length));
+
+ 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;
+ }
+
+ dump_data_pw("pdu data ", whole_pdu, pdu_length);
+
+ 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);
+
+ dump_data_pw("ntlmssp v2 sig ", 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++;
+
+ dump_arc4_state("ntlmssp hash: \n",
+ &ntlmssp_state->crypt->ntlm.seal_state);
+ arcfour_crypt_sbox(&ntlmssp_state->crypt->ntlm.seal_state,
+ sig->data+4, sig->length-4);
+ }
+ 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;
+
+ if (!(ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_SIGN)) {
+ DEBUG(3, ("NTLMSSP Signing not negotiated - cannot sign packet!\n"));
+ return NT_STATUS_INVALID_PARAMETER;
+ }
+
+ 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,
+ sig_mem_ctx,
+ data, length,
+ whole_pdu, pdu_length,
+ NTLMSSP_SEND, sig, true);
+
+ 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(struct ntlmssp_state *ntlmssp_state,
+ 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;
+ TALLOC_CTX *tmp_ctx;
+
+ 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));
+ }
+
+ tmp_ctx = talloc_new(ntlmssp_state);
+ if (!tmp_ctx) {
+ return NT_STATUS_NO_MEMORY;
+ }
+
+ nt_status = ntlmssp_make_packet_signature(ntlmssp_state,
+ tmp_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)));
+ talloc_free(tmp_ctx);
+ 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(5, ("BAD SIG NTLM2: wanted signature of\n"));
+ dump_data(5, local_sig.data, local_sig.length);
+
+ DEBUG(5, ("BAD SIG: got signature of\n"));
+ dump_data(5, sig->data, sig->length);
+
+ DEBUG(0, ("NTLMSSP NTLM2 packet check failed due to invalid signature!\n"));
+ talloc_free(tmp_ctx);
+ 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(5, ("BAD SIG NTLM1: wanted signature of\n"));
+ dump_data(5, local_sig.data, local_sig.length);
+
+ DEBUG(5, ("BAD SIG: got signature of\n"));
+ dump_data(5, sig->data, sig->length);
+
+ DEBUG(0, ("NTLMSSP NTLM1 packet check failed due to invalid signature!\n"));
+ talloc_free(tmp_ctx);
+ return NT_STATUS_ACCESS_DENIED;
+ }
+ }
+ dump_data_pw("checked ntlmssp signature\n", sig->data, sig->length);
+ DEBUG(10,("ntlmssp_check_packet: NTLMSSP signature OK !\n"));
+
+ talloc_free(tmp_ctx);
+ 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->neg_flags & NTLMSSP_NEGOTIATE_SEAL)) {
+ DEBUG(3, ("NTLMSSP Sealing not negotiated - cannot seal packet!\n"));
+ return NT_STATUS_INVALID_PARAMETER;
+ }
+
+ 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
+ */
+
+ dump_arc4_state("ntlmv1 arc4 state:\n",
+ &ntlmssp_state->crypt->ntlm.seal_state);
+ arcfour_crypt_sbox(&ntlmssp_state->crypt->ntlm.seal_state,
+ data, length);
+
+ dump_arc4_state("ntlmv1 arc4 state:\n",
+ &ntlmssp_state->crypt->ntlm.seal_state);
+
+ 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,
+ 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;
+ }
+
+ DEBUG(10,("ntlmssp_unseal_packet: seal\n"));
+ dump_data_pw("ntlmssp sealed data\n", data, length);
+
+ if (ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_NTLM2) {
+ /* First unseal the data. */
+ arcfour_crypt_sbox(&ntlmssp_state->crypt->ntlm2.receiving.seal_state,
+ data, length);
+ dump_data_pw("ntlmv2 clear data\n", data, length);
+ } else {
+ arcfour_crypt_sbox(&ntlmssp_state->crypt->ntlm.seal_state,
+ data, length);
+ dump_data_pw("ntlmv1 clear data\n", data, length);
+ }
+ status = ntlmssp_check_packet(ntlmssp_state,
+ 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;
+}
git.samba.org / amitay / samba.git / blobdiff