diff options
Diffstat (limited to 'source/libsmb/ntlm_check.c')
| -rw-r--r-- | source/libsmb/ntlm_check.c | 377 |
1 files changed, 377 insertions, 0 deletions
diff --git a/source/libsmb/ntlm_check.c b/source/libsmb/ntlm_check.c new file mode 100644 index 00000000000..362b640f913 --- /dev/null +++ b/source/libsmb/ntlm_check.c @@ -0,0 +1,377 @@ +/* + Unix SMB/CIFS implementation. + Password and authentication handling + Copyright (C) Andrew Tridgell 1992-2000 + Copyright (C) Luke Kenneth Casson Leighton 1996-2000 + Copyright (C) Andrew Bartlett 2001-2003 + Copyright (C) Gerald Carter 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 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., 675 Mass Ave, Cambridge, MA 02139, USA. +*/ + +#include "includes.h" + +#undef DBGC_CLASS +#define DBGC_CLASS DBGC_AUTH + +/**************************************************************************** + Core of smb password checking routine. +****************************************************************************/ + +static BOOL smb_pwd_check_ntlmv1(const DATA_BLOB *nt_response, + const uchar *part_passwd, + const DATA_BLOB *sec_blob, + DATA_BLOB *user_sess_key) +{ + /* Finish the encryption of part_passwd. */ + uchar p24[24]; + + if (part_passwd == NULL) { + DEBUG(10,("No password set - DISALLOWING access\n")); + /* No password set - always false ! */ + return False; + } + + if (sec_blob->length != 8) { + DEBUG(0, ("smb_pwd_check_ntlmv1: incorrect challenge size (%lu)\n", + (unsigned long)sec_blob->length)); + return False; + } + + if (nt_response->length != 24) { + DEBUG(0, ("smb_pwd_check_ntlmv1: incorrect password length (%lu)\n", + (unsigned long)nt_response->length)); + return False; + } + + SMBOWFencrypt(part_passwd, sec_blob->data, p24); + if (user_sess_key != NULL) { + *user_sess_key = data_blob(NULL, 16); + SMBsesskeygen_ntv1(part_passwd, NULL, user_sess_key->data); + } + + +#if DEBUG_PASSWORD + DEBUG(100,("Part password (P16) was |\n")); + dump_data(100, part_passwd, 16); + DEBUGADD(100,("Password from client was |\n")); + dump_data(100, nt_response->data, nt_response->length); + DEBUGADD(100,("Given challenge was |\n")); + dump_data(100, sec_blob->data, sec_blob->length); + DEBUGADD(100,("Value from encryption was |\n")); + dump_data(100, p24, 24); +#endif + return (memcmp(p24, nt_response->data, 24) == 0); +} + +/**************************************************************************** + Core of smb password checking routine. (NTLMv2, LMv2) + Note: The same code works with both NTLMv2 and LMv2. +****************************************************************************/ + +static BOOL smb_pwd_check_ntlmv2(const DATA_BLOB *ntv2_response, + const uchar *part_passwd, + const DATA_BLOB *sec_blob, + const char *user, const char *domain, + DATA_BLOB *user_sess_key) +{ + /* Finish the encryption of part_passwd. */ + uchar kr[16]; + uchar value_from_encryption[16]; + uchar client_response[16]; + DATA_BLOB client_key_data; + + if (part_passwd == NULL) { + DEBUG(10,("No password set - DISALLOWING access\n")); + /* No password set - always False */ + return False; + } + + if (sec_blob->length != 8) { + DEBUG(0, ("smb_pwd_check_ntlmv2: incorrect challenge size (%lu)\n", + (unsigned long)sec_blob->length)); + return False; + } + + if (ntv2_response->length < 24) { + /* We MUST have more than 16 bytes, or the stuff below will go + crazy. No known implementation sends less than the 24 bytes + for LMv2, let alone NTLMv2. */ + DEBUG(0, ("smb_pwd_check_ntlmv2: incorrect password length (%lu)\n", + (unsigned long)ntv2_response->length)); + return False; + } + + client_key_data = data_blob(ntv2_response->data+16, ntv2_response->length-16); + /* + todo: should we be checking this for anything? We can't for LMv2, + but for NTLMv2 it is meant to contain the current time etc. + */ + + memcpy(client_response, ntv2_response->data, sizeof(client_response)); + + if (!ntv2_owf_gen(part_passwd, user, domain, kr)) { + return False; + } + + SMBOWFencrypt_ntv2(kr, sec_blob, &client_key_data, value_from_encryption); + if (user_sess_key != NULL) { + *user_sess_key = data_blob(NULL, 16); + SMBsesskeygen_ntv2(kr, value_from_encryption, user_sess_key->data); + } + +#if DEBUG_PASSWORD + DEBUG(100,("Part password (P16) was |\n")); + dump_data(100, part_passwd, 16); + DEBUGADD(100,("Password from client was |\n")); + dump_data(100, ntv2_response->data, ntv2_response->length); + DEBUGADD(100,("Variable data from client was |\n")); + dump_data(100, client_key_data.data, client_key_data.length); + DEBUGADD(100,("Given challenge was |\n")); + dump_data(100, sec_blob->data, sec_blob->length); + DEBUGADD(100,("Value from encryption was |\n")); + dump_data(100, value_from_encryption, 16); +#endif + data_blob_clear_free(&client_key_data); + return (memcmp(value_from_encryption, client_response, 16) == 0); +} + +/** + * Check a challenge-response password against the value of the NT or + * LM password hash. + * + * @param mem_ctx talloc context + * @param challenge 8-byte challenge. If all zero, forces plaintext comparison + * @param nt_response 'unicode' NT response to the challenge, or unicode password + * @param lm_response ASCII or LANMAN response to the challenge, or password in DOS code page + * @param username internal Samba username, for log messages + * @param client_username username the client used + * @param client_domain domain name the client used (may be mapped) + * @param nt_pw MD4 unicode password from our passdb or similar + * @param lm_pw LANMAN ASCII password from our passdb or similar + * @param user_sess_key User session key + * @param lm_sess_key LM session key (first 8 bytes of the LM hash) + */ + +NTSTATUS ntlm_password_check(TALLOC_CTX *mem_ctx, + const DATA_BLOB *challenge, + const DATA_BLOB *lm_response, + const DATA_BLOB *nt_response, + const char *username, + const char *client_username, + const char *client_domain, + const uint8 *lm_pw, const uint8 *nt_pw, + DATA_BLOB *user_sess_key, + DATA_BLOB *lm_sess_key) +{ + static const unsigned char zeros[8]; + if (nt_pw == NULL) { + DEBUG(3,("ntlm_password_check: NO NT password stored for user %s.\n", + username)); + } + + /* Check for cleartext netlogon. Used by Exchange 5.5. */ + if (challenge->length == sizeof(zeros) && + (memcmp(challenge->data, zeros, challenge->length) == 0 )) { + + DEBUG(4,("ntlm_password_check: checking plaintext passwords for user %s\n", + username)); + if (nt_pw && nt_response->length) { + unsigned char pwhash[16]; + mdfour(pwhash, nt_response->data, nt_response->length); + if (memcmp(pwhash, nt_pw, sizeof(pwhash)) == 0) { + return NT_STATUS_OK; + } else { + DEBUG(3,("ntlm_password_check: NT (Unicode) plaintext password check failed for user %s\n", + username)); + return NT_STATUS_WRONG_PASSWORD; + } + + } else if (!lp_lanman_auth()) { + DEBUG(3,("ntlm_password_check: (plaintext password check) LANMAN passwords NOT PERMITTED for user %s\n", + username)); + + } else if (lm_pw && lm_response->length) { + uchar dospwd[14]; + uchar p16[16]; + ZERO_STRUCT(dospwd); + + memcpy(dospwd, lm_response->data, MIN(lm_response->length, sizeof(dospwd))); + /* Only the fisrt 14 chars are considered, password need not be null terminated. */ + + /* we *might* need to upper-case the string here */ + E_P16((const unsigned char *)dospwd, p16); + + if (memcmp(p16, lm_pw, sizeof(p16)) == 0) { + return NT_STATUS_OK; + } else { + DEBUG(3,("ntlm_password_check: LANMAN (ASCII) plaintext password check failed for user %s\n", + username)); + return NT_STATUS_WRONG_PASSWORD; + } + } else { + DEBUG(3, ("Plaintext authentication for user %s attempted, but neither NT nor LM passwords available\n", username)); + return NT_STATUS_WRONG_PASSWORD; + } + } + + if (nt_response->length != 0 && nt_response->length < 24) { + DEBUG(2,("ntlm_password_check: invalid NT password length (%lu) for user %s\n", + (unsigned long)nt_response->length, username)); + } + + if (nt_response->length >= 24 && nt_pw) { + if (nt_response->length > 24) { + /* We have the NT MD4 hash challenge available - see if we can + use it (ie. does it exist in the smbpasswd file). + */ + DEBUG(4,("ntlm_password_check: Checking NTLMv2 password with domain [%s]\n", client_domain)); + if (smb_pwd_check_ntlmv2( nt_response, + nt_pw, challenge, + client_username, + client_domain, + user_sess_key)) { + return NT_STATUS_OK; + } + + DEBUG(4,("ntlm_password_check: Checking NTLMv2 password without a domain\n")); + if (smb_pwd_check_ntlmv2( nt_response, + nt_pw, challenge, + client_username, + "", + user_sess_key)) { + return NT_STATUS_OK; + } else { + DEBUG(3,("ntlm_password_check: NTLMv2 password check failed\n")); + return NT_STATUS_WRONG_PASSWORD; + } + } + + if (lp_ntlm_auth()) { + /* We have the NT MD4 hash challenge available - see if we can + use it (ie. does it exist in the smbpasswd file). + */ + DEBUG(4,("ntlm_password_check: Checking NT MD4 password\n")); + if (smb_pwd_check_ntlmv1(nt_response, + nt_pw, challenge, + user_sess_key)) { + /* The LM session key for this response is not very secure, + so use it only if we otherwise allow LM authentication */ + + if (lp_lanman_auth() && lm_pw) { + uint8 first_8_lm_hash[16]; + memcpy(first_8_lm_hash, lm_pw, 8); + memset(first_8_lm_hash + 8, '\0', 8); + *lm_sess_key = data_blob(first_8_lm_hash, 16); + } + return NT_STATUS_OK; + } else { + DEBUG(3,("ntlm_password_check: NT MD4 password check failed for user %s\n", + username)); + return NT_STATUS_WRONG_PASSWORD; + } + } else { + DEBUG(2,("ntlm_password_check: NTLMv1 passwords NOT PERMITTED for user %s\n", + username)); + /* no return, becouse we might pick up LMv2 in the LM field */ + } + } + + if (lm_response->length == 0) { + DEBUG(3,("ntlm_password_check: NEITHER LanMan nor NT password supplied for user %s\n", + username)); + return NT_STATUS_WRONG_PASSWORD; + } + + if (lm_response->length < 24) { + DEBUG(2,("ntlm_password_check: invalid LanMan password length (%lu) for user %s\n", + (unsigned long)nt_response->length, username)); + return NT_STATUS_WRONG_PASSWORD; + } + + if (!lp_lanman_auth()) { + DEBUG(3,("ntlm_password_check: Lanman passwords NOT PERMITTED for user %s\n", + username)); + } else if (!lm_pw) { + DEBUG(3,("ntlm_password_check: NO LanMan password set for user %s (and no NT password supplied)\n", + username)); + } else { + DEBUG(4,("ntlm_password_check: Checking LM password\n")); + if (smb_pwd_check_ntlmv1(lm_response, + lm_pw, challenge, + NULL)) { + uint8 first_8_lm_hash[16]; + memcpy(first_8_lm_hash, lm_pw, 8); + memset(first_8_lm_hash + 8, '\0', 8); + *user_sess_key = data_blob(first_8_lm_hash, 16); + *lm_sess_key = data_blob(first_8_lm_hash, 16); + return NT_STATUS_OK; + } + } + + if (!nt_pw) { + DEBUG(4,("ntlm_password_check: LM password check failed for user, no NT password %s\n",username)); + return NT_STATUS_WRONG_PASSWORD; + } + + /* This is for 'LMv2' authentication. almost NTLMv2 but limited to 24 bytes. + - related to Win9X, legacy NAS pass-though authentication + */ + DEBUG(4,("ntlm_password_check: Checking LMv2 password with domain %s\n", client_domain)); + if (smb_pwd_check_ntlmv2( lm_response, + nt_pw, challenge, + client_username, + client_domain, + NULL)) { + return NT_STATUS_OK; + } + + DEBUG(4,("ntlm_password_check: Checking LMv2 password without a domain\n")); + if (smb_pwd_check_ntlmv2( lm_response, + nt_pw, challenge, + client_username, + "", + NULL)) { + return NT_STATUS_OK; + } + + /* Apparently NT accepts NT responses in the LM field + - I think this is related to Win9X pass-though authentication + */ + DEBUG(4,("ntlm_password_check: Checking NT MD4 password in LM field\n")); + if (lp_ntlm_auth()) { + if (smb_pwd_check_ntlmv1(lm_response, + nt_pw, challenge, + NULL)) { + /* The session key for this response is still very odd. + It not very secure, so use it only if we otherwise + allow LM authentication */ + + if (lp_lanman_auth() && lm_pw) { + uint8 first_8_lm_hash[16]; + memcpy(first_8_lm_hash, lm_pw, 8); + memset(first_8_lm_hash + 8, '\0', 8); + *user_sess_key = data_blob(first_8_lm_hash, 16); + *lm_sess_key = data_blob(first_8_lm_hash, 16); + } + return NT_STATUS_OK; + } + DEBUG(3,("ntlm_password_check: LM password, NT MD4 password in LM field and LMv2 failed for user %s\n",username)); + } else { + DEBUG(3,("ntlm_password_check: LM password and LMv2 failed for user %s, and NT MD4 password in LM field not permitted\n",username)); + } + return NT_STATUS_WRONG_PASSWORD; +} + |