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Diffstat (limited to 'source3/libsmb/clisigning.c')
| -rw-r--r-- | source3/libsmb/clisigning.c | 1006 |
1 files changed, 1006 insertions, 0 deletions
diff --git a/source3/libsmb/clisigning.c b/source3/libsmb/clisigning.c new file mode 100644 index 0000000000..a3ed0e7572 --- /dev/null +++ b/source3/libsmb/clisigning.c @@ -0,0 +1,1006 @@ +/* + 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, bool cancel) +{ + 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. */ + if (cancel) { + 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; +} |