diff options
Diffstat (limited to 'source4/auth/gensec/ntlmssp_sign.c')
| -rw-r--r-- | source4/auth/gensec/ntlmssp_sign.c | 449 |
1 files changed, 449 insertions, 0 deletions
diff --git a/source4/auth/gensec/ntlmssp_sign.c b/source4/auth/gensec/ntlmssp_sign.c new file mode 100644 index 0000000000..347a85da77 --- /dev/null +++ b/source4/auth/gensec/ntlmssp_sign.c @@ -0,0 +1,449 @@ +/* + * Unix SMB/CIFS implementation. + * Version 3.0 + * NTLMSSP Signing routines + * Copyright (C) Luke Kenneth Casson Leighton 1996-2001 + * Copyright (C) Andrew Bartlett <abartlet@samba.org> 2003-2004 + * + * 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" +#include "auth/auth.h" +#include "lib/crypto/crypto.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: + * + * This code works correctly for the sealing part of the problem. If + * we disable the check for valid client signatures, then we see that + * the output of a rpcecho 'sinkdata' at smbd is correct. We get the + * valid data, and it is validly decrypted. + * + * This means that the quantity of data passing though the RC4 sealing + * pad is correct. + * + * This code also correctly matches test values that I have obtained, + * claiming to be the correct output of NTLM2 signature generation. + * + */ + +static void calc_ntlmv2_key(TALLOC_CTX *mem_ctx, + DATA_BLOB *subkey, + DATA_BLOB session_key, + const char *constant) +{ + struct MD5Context ctx3; + *subkey = data_blob_talloc(mem_ctx, NULL, 16); + MD5Init(&ctx3); + MD5Update(&ctx3, session_key.data, session_key.length); + MD5Update(&ctx3, constant, strlen(constant)+1); + MD5Final(subkey->data, &ctx3); +} + +enum ntlmssp_direction { + NTLMSSP_SEND, + NTLMSSP_RECEIVE +}; + +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->ntlm2_send_seq_num); + ntlmssp_state->ntlm2_send_seq_num++; + hmac_md5_init_limK_to_64(ntlmssp_state->send_sign_key.data, + ntlmssp_state->send_sign_key.length, &ctx); + break; + case NTLMSSP_RECEIVE: + 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.data, + ntlmssp_state->recv_sign_key.length, &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->send_seal_hash, digest, 8); + break; + case NTLMSSP_RECEIVE: + arcfour_crypt_sbox(ntlmssp_state->recv_seal_hash, digest, 8); + break; + } + } + + SIVAL(sig->data, 0, NTLMSSP_SIGN_VERSION); + memcpy(sig->data + 4, digest, 8); + memcpy(sig->data + 12, seq_num, 4); + + } else { + uint32_t crc; + crc = crc32_calc_buffer(data, length); + if (!msrpc_gen(sig_mem_ctx, sig, "dddd", NTLMSSP_SIGN_VERSION, 0, crc, ntlmssp_state->ntlm_seq_num)) { + return NT_STATUS_NO_MEMORY; + } + ntlmssp_state->ntlm_seq_num++; + + arcfour_crypt_sbox(ntlmssp_state->ntlmssp_hash, sig->data+4, sig->length-4); + } + dump_data_pw("calculated ntlmssp signature\n", 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) +{ + if (!ntlmssp_state->session_key.length) { + DEBUG(3, ("NO session key, cannot check sign packet\n")); + return NT_STATUS_NO_USER_SESSION_KEY; + } + + if (!ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_SIGN) { + DEBUG(3, ("NTLMSSP Signing not negotiated - cannot sign packet!\n")); + return NT_STATUS_INVALID_PARAMETER; + } + + return ntlmssp_make_packet_signature(ntlmssp_state, sig_mem_ctx, + data, length, + whole_pdu, pdu_length, + NTLMSSP_SEND, sig, True); +} + +/** + * 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; + } + + 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, 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 check 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(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")); + 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")); + return NT_STATUS_ACCESS_DENIED; + } + } + dump_data_pw("checked ntlmssp signature\n", sig->data, sig->length); + + 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) +{ + NTSTATUS nt_status; + if (!ntlmssp_state->session_key.length) { + DEBUG(3, ("NO session key, cannot seal packet\n")); + return NT_STATUS_NO_USER_SESSION_KEY; + } + + if (!ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_SEAL) { + DEBUG(3, ("NTLMSSP Sealing not negotiated - cannot seal packet!\n")); + return NT_STATUS_INVALID_PARAMETER; + } + + 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 */ + nt_status = ntlmssp_make_packet_signature(ntlmssp_state, sig_mem_ctx, + data, length, + whole_pdu, pdu_length, + NTLMSSP_SEND, sig, False); + arcfour_crypt_sbox(ntlmssp_state->send_seal_hash, data, length); + if (ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_KEY_EXCH) { + arcfour_crypt_sbox(ntlmssp_state->send_seal_hash, sig->data+4, 8); + } + } else { + uint32_t crc; + crc = crc32_calc_buffer(data, length); + if (!msrpc_gen(sig_mem_ctx, sig, "dddd", NTLMSSP_SIGN_VERSION, 0, crc, ntlmssp_state->ntlm_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 ntlmssp_hash is not + constant, but is is rather updated with each + iteration */ + + arcfour_crypt_sbox(ntlmssp_state->ntlmssp_hash, data, length); + arcfour_crypt_sbox(ntlmssp_state->ntlmssp_hash, sig->data+4, sig->length-4); + /* increment counter on send */ + ntlmssp_state->ntlm_seq_num++; + nt_status = NT_STATUS_OK; + } + dump_data_pw("ntlmssp signature\n", sig->data, sig->length); + dump_data_pw("ntlmssp sealed data\n", data, length); + + + return nt_status; +} + +/** + * 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, + DATA_BLOB *sig) +{ + DATA_BLOB local_sig; + NTSTATUS nt_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->recv_seal_hash, data, length); + + 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)) { + return nt_status; + } + + 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")); + return NT_STATUS_ACCESS_DENIED; + } + + dump_data_pw("ntlmssp clear data\n", data, length); + return NT_STATUS_OK; + } else { + arcfour_crypt_sbox(ntlmssp_state->ntlmssp_hash, data, length); + dump_data_pw("ntlmssp clear data\n", data, length); + return ntlmssp_check_packet(ntlmssp_state, sig_mem_ctx, data, length, whole_pdu, pdu_length, sig); + } +} + +/** + Initialise the state for NTLMSSP signing. +*/ +NTSTATUS ntlmssp_sign_init(struct ntlmssp_state *ntlmssp_state) +{ + uint8_t p24[24]; + ZERO_STRUCT(p24); + + DEBUG(3, ("NTLMSSP Sign/Seal - Initialising with flags:\n")); + debug_ntlmssp_flags(ntlmssp_state->neg_flags); + + if (!ntlmssp_state->session_key.length) { + 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: + 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 = 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); + + /* SEND */ + calc_ntlmv2_key(ntlmssp_state, + &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.data, + ntlmssp_state->send_sign_key.length); + + calc_ntlmv2_key(ntlmssp_state, + &ntlmssp_state->send_seal_key, + weak_session_key, send_seal_const); + dump_data_pw("NTLMSSP send seal key:\n", + ntlmssp_state->send_seal_key.data, + ntlmssp_state->send_seal_key.length); + + arcfour_init(ntlmssp_state->send_seal_hash, + &ntlmssp_state->send_seal_key); + + dump_data_pw("NTLMSSP send sesl hash:\n", + ntlmssp_state->send_seal_hash, + sizeof(ntlmssp_state->send_seal_hash)); + + /* RECV */ + calc_ntlmv2_key(ntlmssp_state, + &ntlmssp_state->recv_sign_key, + ntlmssp_state->session_key, recv_sign_const); + dump_data_pw("NTLMSSP recv sign key:\n", + ntlmssp_state->recv_sign_key.data, + ntlmssp_state->recv_sign_key.length); + + calc_ntlmv2_key(ntlmssp_state, + &ntlmssp_state->recv_seal_key, + weak_session_key, recv_seal_const); + dump_data_pw("NTLMSSP recv seal key:\n", + ntlmssp_state->recv_seal_key.data, + ntlmssp_state->recv_seal_key.length); + arcfour_init(ntlmssp_state->recv_seal_hash, + &ntlmssp_state->recv_seal_key); + + dump_data_pw("NTLMSSP receive seal hash:\n", + ntlmssp_state->recv_seal_hash, + sizeof(ntlmssp_state->recv_seal_hash)); + } else { + DEBUG(5, ("NTLMSSP Sign/Seal - using NTLM1\n")); + + arcfour_init(ntlmssp_state->ntlmssp_hash, + &ntlmssp_state->session_key); + dump_data_pw("NTLMSSP hash:\n", ntlmssp_state->ntlmssp_hash, + sizeof(ntlmssp_state->ntlmssp_hash)); + } + + ntlmssp_state->ntlm_seq_num = 0; + ntlmssp_state->ntlm2_send_seq_num = 0; + ntlmssp_state->ntlm2_recv_seq_num = 0; + + return NT_STATUS_OK; +} |