--- /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 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"
+
+/**
+ * Some notes on then 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 calc_ntlmv2_key(unsigned char 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 unsigned char *)constant, strlen(constant)+1);
+ MD5Final(subkey, &ctx3);
+}
+
+enum ntlmssp_direction {
+ NTLMSSP_SEND,
+ NTLMSSP_RECEIVE
+};
+
+static NTSTATUS ntlmssp_make_packet_signature(NTLMSSP_STATE *ntlmssp_state,
+ const uchar *data, size_t length,
+ const uchar *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;
+ uchar seq_num[4];
+ uchar digest[16];
+
+ *sig = data_blob(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->ntlm2_send_seq_num,
+ (unsigned int)length,
+ (unsigned int)pdu_length));
+
+ SIVAL(seq_num, 0, ntlmssp_state->ntlm2_send_seq_num);
+ ntlmssp_state->ntlm2_send_seq_num++;
+ hmac_md5_init_limK_to_64(ntlmssp_state->send_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->ntlm2_recv_seq_num,
+ (unsigned int)length,
+ (unsigned int)pdu_length));
+
+ SIVAL(seq_num, 0, ntlmssp_state->ntlm2_recv_seq_num);
+ ntlmssp_state->ntlm2_recv_seq_num++;
+ hmac_md5_init_limK_to_64(ntlmssp_state->recv_sign_key, 16, &ctx);
+ break;
+ }
+
+ dump_data_pw("pdu data ", whole_pdu, pdu_length);
+
+ hmac_md5_update(seq_num, 4, &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:
+ smb_arc4_crypt(ntlmssp_state->send_seal_arc4_state, digest, 8);
+ break;
+ case NTLMSSP_RECEIVE:
+ smb_arc4_crypt(ntlmssp_state->recv_seal_arc4_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 {
+ uint32 crc;
+ crc = crc32_calc_buffer((const char *)data, length);
+ if (!msrpc_gen(sig, "dddd", NTLMSSP_SIGN_VERSION, 0, crc, ntlmssp_state->ntlmv1_seq_num)) {
+ return NT_STATUS_NO_MEMORY;
+ }
+
+ ntlmssp_state->ntlmv1_seq_num++;
+
+ dump_data_pw("ntlmssp hash:\n", ntlmssp_state->ntlmv1_arc4_state,
+ sizeof(ntlmssp_state->ntlmv1_arc4_state));
+ smb_arc4_crypt(ntlmssp_state->ntlmv1_arc4_state, sig->data+4, sig->length-4);
+ }
+ return NT_STATUS_OK;
+}
+
+NTSTATUS ntlmssp_sign_packet(NTLMSSP_STATE *ntlmssp_state,
+ const uchar *data, size_t length,
+ const uchar *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,
+ 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(NTLMSSP_STATE *ntlmssp_state,
+ const uchar *data, size_t length,
+ const uchar *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;
+ }
+
+ 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,
+ whole_pdu, pdu_length,
+ NTLMSSP_RECEIVE, &local_sig, True);
+
+ if (!NT_STATUS_IS_OK(nt_status)) {
+ DEBUG(0, ("NTLMSSP packet check failed with %s\n", nt_errstr(nt_status)));
+ data_blob_free(&local_sig);
+ 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, (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 NTLM2 packet check failed due to invalid signature!\n"));
+ 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(5, ("BAD SIG NTLM1: 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 NTLM1 packet check failed due to invalid signature!\n"));
+ data_blob_free(&local_sig);
+ 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"));
+
+ data_blob_free(&local_sig);
+ return NT_STATUS_OK;
+}
+
+/**
+ * Seal data with the NTLMSSP algorithm
+ *
+ */
+
+NTSTATUS ntlmssp_seal_packet(NTLMSSP_STATE *ntlmssp_state,
+ uchar *data, size_t length,
+ uchar *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) {
+ /* The order of these two operations matters - we must first seal the packet,
+ then seal the sequence number - this is becouse the send_seal_hash is not
+ constant, but is is rather updated with each iteration */
+ NTSTATUS nt_status = ntlmssp_make_packet_signature(ntlmssp_state,
+ data, length,
+ whole_pdu, pdu_length,
+ NTLMSSP_SEND, sig, False);
+ if (!NT_STATUS_IS_OK(nt_status)) {
+ return nt_status;
+ }
+
+ smb_arc4_crypt(ntlmssp_state->send_seal_arc4_state, data, length);
+ if (ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_KEY_EXCH) {
+ smb_arc4_crypt(ntlmssp_state->send_seal_arc4_state, sig->data+4, 8);
+ }
+ } else {
+ uint32 crc;
+ crc = crc32_calc_buffer((const char *)data, length);
+ if (!msrpc_gen(sig, "dddd", NTLMSSP_SIGN_VERSION, 0, crc, ntlmssp_state->ntlmv1_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 ntlmv1_arc4_state is not
+ constant, but is is rather updated with each iteration */
+
+ dump_data_pw("ntlmv1 arc4 state:\n", ntlmssp_state->ntlmv1_arc4_state,
+ sizeof(ntlmssp_state->ntlmv1_arc4_state));
+ smb_arc4_crypt(ntlmssp_state->ntlmv1_arc4_state, data, length);
+
+ dump_data_pw("ntlmv1 arc4 state:\n", ntlmssp_state->ntlmv1_arc4_state,
+ sizeof(ntlmssp_state->ntlmv1_arc4_state));
+
+ smb_arc4_crypt(ntlmssp_state->ntlmv1_arc4_state, sig->data+4, sig->length-4);
+
+ ntlmssp_state->ntlmv1_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(NTLMSSP_STATE *ntlmssp_state,
+ uchar *data, size_t length,
+ uchar *whole_pdu, size_t pdu_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) {
+ /* First unseal the data. */
+ smb_arc4_crypt(ntlmssp_state->recv_seal_arc4_state, data, length);
+ dump_data_pw("ntlmv2 clear data\n", data, length);
+ } else {
+ smb_arc4_crypt(ntlmssp_state->ntlmv1_arc4_state, data, length);
+ dump_data_pw("ntlmv1 clear data\n", data, length);
+ }
+ return ntlmssp_check_packet(ntlmssp_state, data, length, whole_pdu, pdu_length, sig);
+}
+
+/**
+ Initialise the state for NTLMSSP signing.
+*/
+NTSTATUS ntlmssp_sign_init(NTLMSSP_STATE *ntlmssp_state)
+{
+ unsigned char p24[24];
+ TALLOC_CTX *mem_ctx;
+ ZERO_STRUCT(p24);
+
+ mem_ctx = talloc_init("weak_keys");
+ if (!mem_ctx) {
+ return NT_STATUS_NO_MEMORY;
+ }
+
+ DEBUG(3, ("NTLMSSP Sign/Seal - Initialising with flags:\n"));
+ debug_ntlmssp_flags(ntlmssp_state->neg_flags);
+
+ if (ntlmssp_state->session_key.length < 8) {
+ talloc_free(mem_ctx);
+ DEBUG(3, ("NO session key, cannot intialise signing\n"));
+ return NT_STATUS_NO_USER_SESSION_KEY;
+ }
+
+ 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;
+
+ 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:
+ talloc_free(mem_ctx);
+ 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.
+ */
+
+ if (ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_128) {
+ ;
+ } 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->send_sign_key,
+ ntlmssp_state->session_key, send_sign_const);
+ dump_data_pw("NTLMSSP send sign key:\n",
+ ntlmssp_state->send_sign_key, 16);
+
+ /* SEND: seal ARCFOUR pad */
+ calc_ntlmv2_key(ntlmssp_state->send_seal_key,
+ weak_session_key, send_seal_const);
+ dump_data_pw("NTLMSSP send seal key:\n",
+ ntlmssp_state->send_seal_key, 16);
+
+ smb_arc4_init(ntlmssp_state->send_seal_arc4_state,
+ ntlmssp_state->send_seal_key, 16);
+
+ dump_data_pw("NTLMSSP send seal arc4 state:\n",
+ ntlmssp_state->send_seal_arc4_state,
+ sizeof(ntlmssp_state->send_seal_arc4_state));
+
+ /* RECV: sign key */
+ calc_ntlmv2_key(ntlmssp_state->recv_sign_key,
+ ntlmssp_state->session_key, recv_sign_const);
+ dump_data_pw("NTLMSSP recv send sign key:\n",
+ ntlmssp_state->recv_sign_key, 16);
+
+ /* RECV: seal ARCFOUR pad */
+ calc_ntlmv2_key(ntlmssp_state->recv_seal_key,
+ weak_session_key, recv_seal_const);
+
+ dump_data_pw("NTLMSSP recv seal key:\n",
+ ntlmssp_state->recv_seal_key, 16);
+
+ smb_arc4_init(ntlmssp_state->recv_seal_arc4_state,
+ ntlmssp_state->recv_seal_key, 16);
+
+ dump_data_pw("NTLMSSP recv seal arc4 state:\n",
+ ntlmssp_state->recv_seal_arc4_state,
+ sizeof(ntlmssp_state->recv_seal_arc4_state));
+
+ ntlmssp_state->ntlm2_send_seq_num = 0;
+ ntlmssp_state->ntlm2_recv_seq_num = 0;
+
+
+ } else {
+#if 0
+ /* Hmmm. Shouldn't we also weaken keys for ntlmv1 ? JRA. */
+
+ DATA_BLOB weak_session_key = ntlmssp_state->session_key;
+ /**
+ 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.
+ */
+
+ if (ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_128) {
+ ;
+ } else if (ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_56) {
+ weak_session_key.length = 6;
+ } else { /* forty bits */
+ weak_session_key.length = 5;
+ }
+ dump_data_pw("NTLMSSP weakend master key:\n",
+ weak_session_key.data,
+ weak_session_key.length);
+#endif
+
+ DATA_BLOB weak_session_key = ntlmssp_weaken_keys(ntlmssp_state, mem_ctx);
+
+ DEBUG(5, ("NTLMSSP Sign/Seal - using NTLM1\n"));
+
+ smb_arc4_init(ntlmssp_state->ntlmv1_arc4_state,
+ weak_session_key.data, weak_session_key.length);
+
+ dump_data_pw("NTLMv1 arc4 state:\n", ntlmssp_state->ntlmv1_arc4_state,
+ sizeof(ntlmssp_state->ntlmv1_arc4_state));
+
+ ntlmssp_state->ntlmv1_seq_num = 0;
+ }
+
+ talloc_free(mem_ctx);
+ return NT_STATUS_OK;
+}
projects / samba / blobdiff