/* Unix SMB/CIFS implementation. SMB Signing Code Copyright (C) Jeremy Allison 2003. Copyright (C) Andrew Bartlett <abartlet@samba.org> 2002-2003 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 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" /* Lookup a packet's MID (multiplex id) and figure out it's sequence number */ struct outstanding_packet_lookup { struct outstanding_packet_lookup *prev, *next; uint16 mid; uint32 reply_seq_num; bool can_delete; /* Set to False in trans state. */ }; struct smb_basic_signing_context { DATA_BLOB mac_key; uint32 send_seq_num; struct outstanding_packet_lookup *outstanding_packet_list; }; static bool store_sequence_for_reply(struct outstanding_packet_lookup **list, uint16 mid, uint32 reply_seq_num) { struct outstanding_packet_lookup *t; /* Ensure we only add a mid once. */ for (t = *list; t; t = t->next) { if (t->mid == mid) { return False; } } t = SMB_XMALLOC_P(struct outstanding_packet_lookup); ZERO_STRUCTP(t); t->mid = mid; t->reply_seq_num = reply_seq_num; t->can_delete = True; /* * Add to the *start* of the list not the end of the list. * This ensures that the *last* send sequence with this mid * is returned by preference. * This can happen if the mid wraps and one of the early * mid numbers didn't get a reply and is still lurking on * the list. JRA. Found by Fran Fabrizio <fran@cis.uab.edu>. */ DLIST_ADD(*list, t); DEBUG(10,("store_sequence_for_reply: stored seq = %u mid = %u\n", (unsigned int)reply_seq_num, (unsigned int)mid )); return True; } static bool get_sequence_for_reply(struct outstanding_packet_lookup **list, uint16 mid, uint32 *reply_seq_num) { struct outstanding_packet_lookup *t; for (t = *list; t; t = t->next) { if (t->mid == mid) { *reply_seq_num = t->reply_seq_num; DEBUG(10,("get_sequence_for_reply: found seq = %u mid = %u\n", (unsigned int)t->reply_seq_num, (unsigned int)t->mid )); if (t->can_delete) { DLIST_REMOVE(*list, t); SAFE_FREE(t); } return True; } } return False; } static bool set_sequence_can_delete_flag(struct outstanding_packet_lookup **list, uint16 mid, bool can_delete_entry) { struct outstanding_packet_lookup *t; for (t = *list; t; t = t->next) { if (t->mid == mid) { t->can_delete = can_delete_entry; return True; } } return False; } /*********************************************************** SMB signing - Common code before we set a new signing implementation ************************************************************/ static bool cli_set_smb_signing_common(struct cli_state *cli) { if (!cli->sign_info.allow_smb_signing) { return False; } if (!cli->sign_info.negotiated_smb_signing && !cli->sign_info.mandatory_signing) { return False; } if (cli->sign_info.doing_signing) { return False; } if (cli->sign_info.free_signing_context) cli->sign_info.free_signing_context(&cli->sign_info); /* These calls are INCOMPATIBLE with SMB signing */ cli->readbraw_supported = False; cli->writebraw_supported = False; return True; } /*********************************************************** SMB signing - Common code for 'real' implementations ************************************************************/ static bool set_smb_signing_real_common(struct smb_sign_info *si) { if (si->mandatory_signing) { DEBUG(5, ("Mandatory SMB signing enabled!\n")); } si->doing_signing = True; DEBUG(5, ("SMB signing enabled!\n")); return True; } static void mark_packet_signed(char *outbuf) { uint16 flags2; flags2 = SVAL(outbuf,smb_flg2); flags2 |= FLAGS2_SMB_SECURITY_SIGNATURES; SSVAL(outbuf,smb_flg2, flags2); } /*********************************************************** SMB signing - NULL implementation - calculate a MAC to send. ************************************************************/ static void null_sign_outgoing_message(char *outbuf, struct smb_sign_info *si) { /* we can't zero out the sig, as we might be trying to send a session request - which is NBT-level, not SMB level and doesn't have the field */ return; } /*********************************************************** SMB signing - NULL implementation - check a MAC sent by server. ************************************************************/ static bool null_check_incoming_message(const char *inbuf, struct smb_sign_info *si, bool must_be_ok) { return True; } /*********************************************************** SMB signing - NULL implementation - free signing context ************************************************************/ static void null_free_signing_context(struct smb_sign_info *si) { return; } /** SMB signing - NULL implementation - setup the MAC key. @note Used as an initialisation only - it will not correctly shut down a real signing mechanism */ static bool null_set_signing(struct smb_sign_info *si) { si->signing_context = NULL; si->sign_outgoing_message = null_sign_outgoing_message; si->check_incoming_message = null_check_incoming_message; si->free_signing_context = null_free_signing_context; return True; } /** * Free the signing context */ static void free_signing_context(struct smb_sign_info *si) { if (si->free_signing_context) { si->free_signing_context(si); si->signing_context = NULL; } null_set_signing(si); } static bool signing_good(const char *inbuf, struct smb_sign_info *si, bool good, uint32 seq, bool must_be_ok) { if (good) { if (!si->doing_signing) { si->doing_signing = True; } if (!si->seen_valid) { si->seen_valid = True; } } else { if (!si->mandatory_signing && !si->seen_valid) { if (!must_be_ok) { return True; } /* Non-mandatory signing - just turn off if this is the first bad packet.. */ DEBUG(5, ("srv_check_incoming_message: signing negotiated but not required and peer\n" "isn't sending correct signatures. Turning off.\n")); si->negotiated_smb_signing = False; si->allow_smb_signing = False; si->doing_signing = False; free_signing_context(si); return True; } else if (!must_be_ok) { /* This packet is known to be unsigned */ return True; } else { /* Mandatory signing or bad packet after signing started - fail and disconnect. */ if (seq) DEBUG(0, ("signing_good: BAD SIG: seq %u\n", (unsigned int)seq)); return False; } } return True; } /*********************************************************** SMB signing - Simple implementation - calculate a MAC on the packet ************************************************************/ static void simple_packet_signature(struct smb_basic_signing_context *data, const uchar *buf, uint32 seq_number, unsigned char calc_md5_mac[16]) { const size_t offset_end_of_sig = (smb_ss_field + 8); unsigned char sequence_buf[8]; struct MD5Context md5_ctx; #if 0 /* JRA - apparently this is incorrect. */ unsigned char key_buf[16]; #endif /* * Firstly put the sequence number into the first 4 bytes. * and zero out the next 4 bytes. * * We do this here, to avoid modifying the packet. */ DEBUG(10,("simple_packet_signature: sequence number %u\n", seq_number )); SIVAL(sequence_buf, 0, seq_number); SIVAL(sequence_buf, 4, 0); /* Calculate the 16 byte MAC - but don't alter the data in the incoming packet. This makes for a bit of fussing about, but it's not too bad. */ MD5Init(&md5_ctx); /* intialise with the key */ MD5Update(&md5_ctx, data->mac_key.data, data->mac_key.length); #if 0 /* JRA - apparently this is incorrect. */ /* NB. When making and verifying SMB signatures, Windows apparently zero-pads the key to 128 bits if it isn't long enough. From Nalin Dahyabhai <nalin@redhat.com> */ if (data->mac_key.length < sizeof(key_buf)) { memset(key_buf, 0, sizeof(key_buf)); MD5Update(&md5_ctx, key_buf, sizeof(key_buf) - data->mac_key.length); } #endif /* copy in the first bit of the SMB header */ MD5Update(&md5_ctx, buf + 4, smb_ss_field - 4); /* copy in the sequence number, instead of the signature */ MD5Update(&md5_ctx, sequence_buf, sizeof(sequence_buf)); /* copy in the rest of the packet in, skipping the signature */ MD5Update(&md5_ctx, buf + offset_end_of_sig, smb_len(buf) - (offset_end_of_sig - 4)); /* calculate the MD5 sig */ MD5Final(calc_md5_mac, &md5_ctx); } /*********************************************************** SMB signing - Client implementation - send the MAC. ************************************************************/ static void client_sign_outgoing_message(char *outbuf, struct smb_sign_info *si) { unsigned char calc_md5_mac[16]; struct smb_basic_signing_context *data = (struct smb_basic_signing_context *)si->signing_context; if (!si->doing_signing) return; /* JRA Paranioa test - we should be able to get rid of this... */ if (smb_len(outbuf) < (smb_ss_field + 8 - 4)) { DEBUG(1, ("client_sign_outgoing_message: Logic error. Can't check signature on short packet! smb_len = %u\n", smb_len(outbuf) )); abort(); } /* mark the packet as signed - BEFORE we sign it...*/ mark_packet_signed(outbuf); simple_packet_signature(data, (const unsigned char *)outbuf, data->send_seq_num, calc_md5_mac); DEBUG(10, ("client_sign_outgoing_message: sent SMB signature of\n")); dump_data(10, calc_md5_mac, 8); memcpy(&outbuf[smb_ss_field], calc_md5_mac, 8); /* cli->outbuf[smb_ss_field+2]=0; Uncomment this to test if the remote server actually verifies signatures...*/ /* Instead of re-introducing the trans_info_conect we used to have here, we use the fact that during a SMBtrans/SMBtrans2/SMBnttrans send that the mid stays constant. This means that calling store_sequence_for_reply() will return False for all trans secondaries, as the mid is already on the stored sequence list. As the send_seqence_number must remain constant for all primary+secondary trans sends, we only increment the send sequence number when we successfully add a new entry to the outstanding sequence list. This means I can isolate the fix here rather than re-adding the trans signing on/off calls in libsmb/clitrans2.c JRA. */ if (store_sequence_for_reply(&data->outstanding_packet_list, SVAL(outbuf,smb_mid), data->send_seq_num + 1)) { data->send_seq_num += 2; } } /*********************************************************** SMB signing - Client implementation - check a MAC sent by server. ************************************************************/ static bool client_check_incoming_message(const char *inbuf, struct smb_sign_info *si, bool must_be_ok) { bool good; uint32 reply_seq_number; unsigned char calc_md5_mac[16]; unsigned char *server_sent_mac; struct smb_basic_signing_context *data = (struct smb_basic_signing_context *)si->signing_context; if (!si->doing_signing) return True; if (smb_len(inbuf) < (smb_ss_field + 8 - 4)) { DEBUG(1, ("client_check_incoming_message: Can't check signature on short packet! smb_len = %u\n", smb_len(inbuf))); return False; } if (!get_sequence_for_reply(&data->outstanding_packet_list, SVAL(inbuf, smb_mid), &reply_seq_number)) { DEBUG(1, ("client_check_incoming_message: received message " "with mid %u with no matching send record.\n", (unsigned int)SVAL(inbuf, smb_mid) )); return False; } simple_packet_signature(data, (const unsigned char *)inbuf, reply_seq_number, calc_md5_mac); server_sent_mac = (unsigned char *)&inbuf[smb_ss_field]; good = (memcmp(server_sent_mac, calc_md5_mac, 8) == 0); if (!good) { DEBUG(5, ("client_check_incoming_message: BAD SIG: wanted SMB signature of\n")); dump_data(5, calc_md5_mac, 8); DEBUG(5, ("client_check_incoming_message: BAD SIG: got SMB signature of\n")); dump_data(5, server_sent_mac, 8); #if 1 /* JRATEST */ { int i; for (i = -5; i < 5; i++) { simple_packet_signature(data, (const unsigned char *)inbuf, reply_seq_number+i, calc_md5_mac); if (memcmp(server_sent_mac, calc_md5_mac, 8) == 0) { DEBUG(0,("client_check_incoming_message: out of seq. seq num %u matches. \ We were expecting seq %u\n", reply_seq_number+i, reply_seq_number )); break; } } } #endif /* JRATEST */ } else { DEBUG(10, ("client_check_incoming_message: seq %u: got good SMB signature of\n", (unsigned int)reply_seq_number)); dump_data(10, server_sent_mac, 8); } return signing_good(inbuf, si, good, reply_seq_number, must_be_ok); } /*********************************************************** SMB signing - Simple implementation - free signing context ************************************************************/ static void simple_free_signing_context(struct smb_sign_info *si) { struct smb_basic_signing_context *data = (struct smb_basic_signing_context *)si->signing_context; struct outstanding_packet_lookup *list; struct outstanding_packet_lookup *next; for (list = data->outstanding_packet_list; list; list = next) { next = list->next; DLIST_REMOVE(data->outstanding_packet_list, list); SAFE_FREE(list); } data_blob_free(&data->mac_key); SAFE_FREE(si->signing_context); return; } /*********************************************************** SMB signing - Simple implementation - setup the MAC key. ************************************************************/ bool cli_simple_set_signing(struct cli_state *cli, const DATA_BLOB user_session_key, const DATA_BLOB response) { struct smb_basic_signing_context *data; if (!user_session_key.length) return False; if (!cli_set_smb_signing_common(cli)) { return False; } if (!set_smb_signing_real_common(&cli->sign_info)) { return False; } data = SMB_XMALLOC_P(struct smb_basic_signing_context); memset(data, '\0', sizeof(*data)); cli->sign_info.signing_context = data; data->mac_key = data_blob(NULL, response.length + user_session_key.length); memcpy(&data->mac_key.data[0], user_session_key.data, user_session_key.length); DEBUG(10, ("cli_simple_set_signing: user_session_key\n")); dump_data(10, user_session_key.data, user_session_key.length); if (response.length) { memcpy(&data->mac_key.data[user_session_key.length],response.data, response.length); DEBUG(10, ("cli_simple_set_signing: response_data\n")); dump_data(10, response.data, response.length); } else { DEBUG(10, ("cli_simple_set_signing: NULL response_data\n")); } dump_data_pw("MAC ssession key is:\n", data->mac_key.data, data->mac_key.length); /* Initialise the sequence number */ data->send_seq_num = 0; /* Initialise the list of outstanding packets */ data->outstanding_packet_list = NULL; cli->sign_info.sign_outgoing_message = client_sign_outgoing_message; cli->sign_info.check_incoming_message = client_check_incoming_message; cli->sign_info.free_signing_context = simple_free_signing_context; return True; } /*********************************************************** SMB signing - TEMP implementation - calculate a MAC to send. ************************************************************/ static void temp_sign_outgoing_message(char *outbuf, struct smb_sign_info *si) { /* mark the packet as signed - BEFORE we sign it...*/ mark_packet_signed(outbuf); /* I wonder what BSRSPYL stands for - but this is what MS actually sends! */ memcpy(&outbuf[smb_ss_field], "BSRSPYL ", 8); return; } /*********************************************************** SMB signing - TEMP implementation - check a MAC sent by server. ************************************************************/ static bool temp_check_incoming_message(const char *inbuf, struct smb_sign_info *si, bool foo) { return True; } /*********************************************************** SMB signing - TEMP implementation - free signing context ************************************************************/ static void temp_free_signing_context(struct smb_sign_info *si) { return; } /*********************************************************** SMB signing - NULL implementation - setup the MAC key. ************************************************************/ bool cli_null_set_signing(struct cli_state *cli) { return null_set_signing(&cli->sign_info); } /*********************************************************** SMB signing - temp implementation - setup the MAC key. ************************************************************/ bool cli_temp_set_signing(struct cli_state *cli) { if (!cli_set_smb_signing_common(cli)) { return False; } cli->sign_info.signing_context = NULL; cli->sign_info.sign_outgoing_message = temp_sign_outgoing_message; cli->sign_info.check_incoming_message = temp_check_incoming_message; cli->sign_info.free_signing_context = temp_free_signing_context; return True; } void cli_free_signing_context(struct cli_state *cli) { free_signing_context(&cli->sign_info); } /** * Sign a packet with the current mechanism */ void cli_calculate_sign_mac(struct cli_state *cli, char *buf) { cli->sign_info.sign_outgoing_message(buf, &cli->sign_info); } /** * Check a packet with the current mechanism * @return False if we had an established signing connection * which had a bad checksum, True otherwise. */ bool cli_check_sign_mac(struct cli_state *cli, char *buf) { if (!cli->sign_info.check_incoming_message(buf, &cli->sign_info, True)) { free_signing_context(&cli->sign_info); return False; } return True; } /*********************************************************** Enter trans/trans2/nttrans state. ************************************************************/ bool client_set_trans_sign_state_on(struct cli_state *cli, uint16 mid) { struct smb_sign_info *si = &cli->sign_info; struct smb_basic_signing_context *data = (struct smb_basic_signing_context *)si->signing_context; if (!si->doing_signing) { return True; } if (!data) { return False; } if (!set_sequence_can_delete_flag(&data->outstanding_packet_list, mid, False)) { return False; } return True; } /*********************************************************** Leave trans/trans2/nttrans state. ************************************************************/ bool client_set_trans_sign_state_off(struct cli_state *cli, uint16 mid) { uint32 reply_seq_num; struct smb_sign_info *si = &cli->sign_info; struct smb_basic_signing_context *data = (struct smb_basic_signing_context *)si->signing_context; if (!si->doing_signing) { return True; } if (!data) { return False; } if (!set_sequence_can_delete_flag(&data->outstanding_packet_list, mid, True)) { return False; } /* Now delete the stored mid entry. */ if (!get_sequence_for_reply(&data->outstanding_packet_list, mid, &reply_seq_num)) { return False; } return True; } /*********************************************************** Is client signing on ? ************************************************************/ bool client_is_signing_on(struct cli_state *cli) { struct smb_sign_info *si = &cli->sign_info; return si->doing_signing; } /*********************************************************** SMB signing - Server implementation - send the MAC. ************************************************************/ static void srv_sign_outgoing_message(char *outbuf, struct smb_sign_info *si) { unsigned char calc_md5_mac[16]; struct smb_basic_signing_context *data = (struct smb_basic_signing_context *)si->signing_context; uint32 send_seq_number = data->send_seq_num-1; uint16 mid; if (!si->doing_signing) { return; } /* JRA Paranioa test - we should be able to get rid of this... */ if (smb_len(outbuf) < (smb_ss_field + 8 - 4)) { DEBUG(1, ("srv_sign_outgoing_message: Logic error. Can't send signature on short packet! smb_len = %u\n", smb_len(outbuf) )); abort(); } /* mark the packet as signed - BEFORE we sign it...*/ mark_packet_signed(outbuf); mid = SVAL(outbuf, smb_mid); /* See if this is a reply for a deferred packet. */ get_sequence_for_reply(&data->outstanding_packet_list, mid, &send_seq_number); simple_packet_signature(data, (const unsigned char *)outbuf, send_seq_number, calc_md5_mac); DEBUG(10, ("srv_sign_outgoing_message: seq %u: sent SMB signature of\n", (unsigned int)send_seq_number)); dump_data(10, calc_md5_mac, 8); memcpy(&outbuf[smb_ss_field], calc_md5_mac, 8); /* cli->outbuf[smb_ss_field+2]=0; Uncomment this to test if the remote client actually verifies signatures...*/ } /*********************************************************** SMB signing - Server implementation - check a MAC sent by server. ************************************************************/ static bool srv_check_incoming_message(const char *inbuf, struct smb_sign_info *si, bool must_be_ok) { bool good; struct smb_basic_signing_context *data = (struct smb_basic_signing_context *)si->signing_context; uint32 reply_seq_number = data->send_seq_num; uint32 saved_seq; unsigned char calc_md5_mac[16]; unsigned char *server_sent_mac; if (!si->doing_signing) return True; if (smb_len(inbuf) < (smb_ss_field + 8 - 4)) { DEBUG(1, ("srv_check_incoming_message: Can't check signature on short packet! smb_len = %u\n", smb_len(inbuf))); return False; } /* We always increment the sequence number. */ data->send_seq_num += 2; saved_seq = reply_seq_number; simple_packet_signature(data, (const unsigned char *)inbuf, reply_seq_number, calc_md5_mac); server_sent_mac = (unsigned char *)&inbuf[smb_ss_field]; good = (memcmp(server_sent_mac, calc_md5_mac, 8) == 0); if (!good) { if (saved_seq) { DEBUG(0, ("srv_check_incoming_message: BAD SIG: seq %u wanted SMB signature of\n", (unsigned int)saved_seq)); dump_data(5, calc_md5_mac, 8); DEBUG(0, ("srv_check_incoming_message: BAD SIG: seq %u got SMB signature of\n", (unsigned int)reply_seq_number)); dump_data(5, server_sent_mac, 8); } #if 1 /* JRATEST */ { int i; reply_seq_number -= 5; for (i = 0; i < 10; i++, reply_seq_number++) { simple_packet_signature(data, (const unsigned char *)inbuf, reply_seq_number, calc_md5_mac); if (memcmp(server_sent_mac, calc_md5_mac, 8) == 0) { DEBUG(0,("srv_check_incoming_message: out of seq. seq num %u matches. \ We were expecting seq %u\n", reply_seq_number, saved_seq )); break; } } } #endif /* JRATEST */ } else { DEBUG(10, ("srv_check_incoming_message: seq %u: (current is %u) got good SMB signature of\n", (unsigned int)reply_seq_number, (unsigned int)data->send_seq_num)); dump_data(10, server_sent_mac, 8); } return (signing_good(inbuf, si, good, saved_seq, must_be_ok)); } /*********************************************************** SMB signing - server API's. ************************************************************/ static struct smb_sign_info srv_sign_info = { null_sign_outgoing_message, null_check_incoming_message, null_free_signing_context, NULL, False, False, False, False }; /*********************************************************** Turn signing off or on for oplock break code. ************************************************************/ bool srv_oplock_set_signing(bool onoff) { bool ret = srv_sign_info.doing_signing; srv_sign_info.doing_signing = onoff; return ret; } /*********************************************************** Called to validate an incoming packet from the client. ************************************************************/ bool srv_check_sign_mac(const char *inbuf, bool must_be_ok) { /* Check if it's a non-session message. */ if(CVAL(inbuf,0)) { return True; } return srv_sign_info.check_incoming_message(inbuf, &srv_sign_info, must_be_ok); } /*********************************************************** Called to sign an outgoing packet to the client. ************************************************************/ void srv_calculate_sign_mac(char *outbuf) { /* Check if it's a non-session message. */ if(CVAL(outbuf,0)) { return; } srv_sign_info.sign_outgoing_message(outbuf, &srv_sign_info); } /*********************************************************** Called by server to defer an outgoing packet. ************************************************************/ void srv_defer_sign_response(uint16 mid) { struct smb_basic_signing_context *data; if (!srv_sign_info.doing_signing) return; data = (struct smb_basic_signing_context *)srv_sign_info.signing_context; if (!data) return; /* * Ensure we only store this mid reply once... */ store_sequence_for_reply(&data->outstanding_packet_list, mid, data->send_seq_num-1); } /*********************************************************** Called to remove sequence records when a deferred packet is cancelled by mid. This should never find one.... ************************************************************/ void srv_cancel_sign_response(uint16 mid) { struct smb_basic_signing_context *data; uint32 dummy_seq; if (!srv_sign_info.doing_signing) return; data = (struct smb_basic_signing_context *)srv_sign_info.signing_context; if (!data) return; DEBUG(10,("srv_cancel_sign_response: for mid %u\n", (unsigned int)mid )); while (get_sequence_for_reply(&data->outstanding_packet_list, mid, &dummy_seq)) ; /* cancel doesn't send a reply so doesn't burn a sequence number. */ data->send_seq_num -= 1; } /*********************************************************** Called by server negprot when signing has been negotiated. ************************************************************/ void srv_set_signing_negotiated(void) { srv_sign_info.allow_smb_signing = True; srv_sign_info.negotiated_smb_signing = True; if (lp_server_signing() == Required) srv_sign_info.mandatory_signing = True; srv_sign_info.sign_outgoing_message = temp_sign_outgoing_message; srv_sign_info.check_incoming_message = temp_check_incoming_message; srv_sign_info.free_signing_context = temp_free_signing_context; } /*********************************************************** Returns whether signing is active. We can't use sendfile or raw reads/writes if it is. ************************************************************/ bool srv_is_signing_active(void) { return srv_sign_info.doing_signing; } /*********************************************************** Returns whether signing is negotiated. We can't use it unless it was in the negprot. ************************************************************/ bool srv_is_signing_negotiated(void) { return srv_sign_info.negotiated_smb_signing; } /*********************************************************** Returns whether signing is actually happening ************************************************************/ bool srv_signing_started(void) { struct smb_basic_signing_context *data; if (!srv_sign_info.doing_signing) { return False; } data = (struct smb_basic_signing_context *)srv_sign_info.signing_context; if (!data) return False; if (data->send_seq_num == 0) { return False; } return True; } /*********************************************************** Turn on signing from this packet onwards. ************************************************************/ void srv_set_signing(const DATA_BLOB user_session_key, const DATA_BLOB response) { struct smb_basic_signing_context *data; if (!user_session_key.length) return; if (!srv_sign_info.negotiated_smb_signing && !srv_sign_info.mandatory_signing) { DEBUG(5,("srv_set_signing: signing negotiated = %u, mandatory_signing = %u. Not allowing smb signing.\n", (unsigned int)srv_sign_info.negotiated_smb_signing, (unsigned int)srv_sign_info.mandatory_signing )); return; } /* Once we've turned on, ignore any more sessionsetups. */ if (srv_sign_info.doing_signing) { return; } if (srv_sign_info.free_signing_context) srv_sign_info.free_signing_context(&srv_sign_info); srv_sign_info.doing_signing = True; data = SMB_XMALLOC_P(struct smb_basic_signing_context); memset(data, '\0', sizeof(*data)); srv_sign_info.signing_context = data; data->mac_key = data_blob(NULL, response.length + user_session_key.length); memcpy(&data->mac_key.data[0], user_session_key.data, user_session_key.length); if (response.length) memcpy(&data->mac_key.data[user_session_key.length],response.data, response.length); dump_data_pw("MAC ssession key is:\n", data->mac_key.data, data->mac_key.length); DEBUG(3,("srv_set_signing: turning on SMB signing: signing negotiated = %s, mandatory_signing = %s.\n", BOOLSTR(srv_sign_info.negotiated_smb_signing), BOOLSTR(srv_sign_info.mandatory_signing) )); /* Initialise the sequence number */ data->send_seq_num = 0; /* Initialise the list of outstanding packets */ data->outstanding_packet_list = NULL; srv_sign_info.sign_outgoing_message = srv_sign_outgoing_message; srv_sign_info.check_incoming_message = srv_check_incoming_message; srv_sign_info.free_signing_context = simple_free_signing_context; }