/* Unix SMB/CIFS implementation. Password and authentication handling Copyright (C) Andrew Bartlett <abartlet@samba.org> 2001-2004 Copyright (C) Gerald Carter 2003 Copyright (C) Luke Kenneth Casson Leighton 1996-2000 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" #include "../lib/crypto/crypto.h" #include "librpc/gen_ndr/netlogon.h" #include "libcli/auth/libcli_auth.h" /**************************************************************************** Core of smb password checking routine. ****************************************************************************/ static bool smb_pwd_check_ntlmv1(TALLOC_CTX *mem_ctx, const DATA_BLOB *nt_response, const uint8_t *part_passwd, const DATA_BLOB *sec_blob, DATA_BLOB *user_sess_key) { /* Finish the encryption of part_passwd. */ uint8_t 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 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 if (memcmp(p24, nt_response->data, 24) == 0) { if (user_sess_key != NULL) { *user_sess_key = data_blob_talloc(mem_ctx, NULL, 16); SMBsesskeygen_ntv1(part_passwd, user_sess_key->data); } return true; } return false; } /**************************************************************************** Core of smb password checking routine. (NTLMv2, LMv2) Note: The same code works with both NTLMv2 and LMv2. ****************************************************************************/ static bool smb_pwd_check_ntlmv2(TALLOC_CTX *mem_ctx, const DATA_BLOB *ntv2_response, const uint8_t *part_passwd, const DATA_BLOB *sec_blob, const char *user, const char *domain, bool upper_case_domain, /* should the domain be transformed into upper case? */ DATA_BLOB *user_sess_key) { /* Finish the encryption of part_passwd. */ uint8_t kr[16]; uint8_t value_from_encryption[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_talloc(mem_ctx, 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. */ if (!ntv2_owf_gen(part_passwd, user, domain, upper_case_domain, kr)) { return false; } SMBOWFencrypt_ntv2(kr, sec_blob, &client_key_data, value_from_encryption); #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); if (memcmp(value_from_encryption, ntv2_response->data, 16) == 0) { if (user_sess_key != NULL) { *user_sess_key = data_blob_talloc(mem_ctx, NULL, 16); SMBsesskeygen_ntv2(kr, value_from_encryption, user_sess_key->data); } return true; } return false; } /**************************************************************************** Core of smb password checking routine. (NTLMv2, LMv2) Note: The same code works with both NTLMv2 and LMv2. ****************************************************************************/ static bool smb_sess_key_ntlmv2(TALLOC_CTX *mem_ctx, const DATA_BLOB *ntv2_response, const uint8_t *part_passwd, const DATA_BLOB *sec_blob, const char *user, const char *domain, bool upper_case_domain, /* should the domain be transformed into upper case? */ DATA_BLOB *user_sess_key) { /* Finish the encryption of part_passwd. */ uint8_t kr[16]; uint8_t value_from_encryption[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_sess_key_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_sess_key_ntlmv2: incorrect password length (%lu)\n", (unsigned long)ntv2_response->length)); return false; } client_key_data = data_blob_talloc(mem_ctx, ntv2_response->data+16, ntv2_response->length-16); if (!ntv2_owf_gen(part_passwd, user, domain, upper_case_domain, kr)) { return false; } SMBOWFencrypt_ntv2(kr, sec_blob, &client_key_data, value_from_encryption); *user_sess_key = data_blob_talloc(mem_ctx, NULL, 16); SMBsesskeygen_ntv2(kr, value_from_encryption, user_sess_key->data); return true; } /** * Compare password hashes against those from the SAM * * @param mem_ctx talloc context * @param client_lanman LANMAN password hash, as supplied by the client * @param client_nt NT (MD4) password hash, as supplied by the client * @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 stored_lanman LANMAN password hash, as stored on the SAM * @param stored_nt NT (MD4) password hash, as stored on the SAM * @param user_sess_key User session key * @param lm_sess_key LM session key (first 8 bytes of the LM hash) */ NTSTATUS hash_password_check(TALLOC_CTX *mem_ctx, bool lanman_auth, const struct samr_Password *client_lanman, const struct samr_Password *client_nt, const char *username, const struct samr_Password *stored_lanman, const struct samr_Password *stored_nt) { if (stored_nt == NULL) { DEBUG(3,("ntlm_password_check: NO NT password stored for user %s.\n", username)); } if (client_nt && stored_nt) { if (memcmp(client_nt->hash, stored_nt->hash, sizeof(stored_nt->hash)) == 0) { return NT_STATUS_OK; } else { DEBUG(3,("ntlm_password_check: Interactive logon: NT password check failed for user %s\n", username)); return NT_STATUS_WRONG_PASSWORD; } } else if (client_lanman && stored_lanman) { if (!lanman_auth) { DEBUG(3,("ntlm_password_check: Interactive logon: only LANMAN password supplied for user %s, and LM passwords are disabled!\n", username)); return NT_STATUS_WRONG_PASSWORD; } if (strchr_m(username, '@')) { return NT_STATUS_NOT_FOUND; } if (memcmp(client_lanman->hash, stored_lanman->hash, sizeof(stored_lanman->hash)) == 0) { return NT_STATUS_OK; } else { DEBUG(3,("ntlm_password_check: Interactive logon: LANMAN password check failed for user %s\n", username)); return NT_STATUS_WRONG_PASSWORD; } } if (strchr_m(username, '@')) { return NT_STATUS_NOT_FOUND; } return NT_STATUS_WRONG_PASSWORD; } /** * 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 stored_lanman LANMAN ASCII password from our passdb or similar * @param stored_nt MD4 unicode 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, bool lanman_auth, bool ntlm_auth, uint32_t logon_parameters, 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 struct samr_Password *stored_lanman, const struct samr_Password *stored_nt, DATA_BLOB *user_sess_key, DATA_BLOB *lm_sess_key) { const static uint8_t zeros[8]; DATA_BLOB tmp_sess_key; if (stored_nt == NULL) { DEBUG(3,("ntlm_password_check: NO NT password stored for user %s.\n", username)); } *lm_sess_key = data_blob(NULL, 0); *user_sess_key = data_blob(NULL, 0); /* Check for cleartext netlogon. Used by Exchange 5.5. */ if ((logon_parameters & MSV1_0_CLEARTEXT_PASSWORD_ALLOWED) && challenge->length == sizeof(zeros) && (memcmp(challenge->data, zeros, challenge->length) == 0 )) { struct samr_Password client_nt; struct samr_Password client_lm; char *unix_pw = NULL; bool lm_ok; DEBUG(4,("ntlm_password_check: checking plaintext passwords for user %s\n", username)); mdfour(client_nt.hash, nt_response->data, nt_response->length); if (lm_response->length && (convert_string_talloc(mem_ctx, CH_DOS, CH_UNIX, lm_response->data, lm_response->length, (void *)&unix_pw, NULL, false))) { if (E_deshash(unix_pw, client_lm.hash)) { lm_ok = true; } else { lm_ok = false; } } else { lm_ok = false; } return hash_password_check(mem_ctx, lanman_auth, lm_ok ? &client_lm : NULL, nt_response->length ? &client_nt : NULL, username, stored_lanman, stored_nt); } 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 && stored_nt) { /* We have the NT MD4 hash challenge available - see if we can use it */ DEBUG(4,("ntlm_password_check: Checking NTLMv2 password with domain [%s]\n", client_domain)); if (smb_pwd_check_ntlmv2(mem_ctx, nt_response, stored_nt->hash, challenge, client_username, client_domain, false, user_sess_key)) { if (user_sess_key->length) { *lm_sess_key = data_blob_talloc(mem_ctx, user_sess_key->data, MIN(8, user_sess_key->length)); } return NT_STATUS_OK; } DEBUG(4,("ntlm_password_check: Checking NTLMv2 password with uppercased version of domain [%s]\n", client_domain)); if (smb_pwd_check_ntlmv2(mem_ctx, nt_response, stored_nt->hash, challenge, client_username, client_domain, true, user_sess_key)) { if (user_sess_key->length) { *lm_sess_key = data_blob_talloc(mem_ctx, user_sess_key->data, MIN(8, user_sess_key->length)); } return NT_STATUS_OK; } DEBUG(4,("ntlm_password_check: Checking NTLMv2 password without a domain\n")); if (smb_pwd_check_ntlmv2(mem_ctx, nt_response, stored_nt->hash, challenge, client_username, "", false, user_sess_key)) { if (user_sess_key->length) { *lm_sess_key = data_blob_talloc(mem_ctx, user_sess_key->data, MIN(8, user_sess_key->length)); } return NT_STATUS_OK; } else { DEBUG(3,("ntlm_password_check: NTLMv2 password check failed\n")); } } else if (nt_response->length == 24 && stored_nt) { if (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(mem_ctx, nt_response, stored_nt->hash, 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 (lanman_auth && stored_lanman) { *lm_sess_key = data_blob_talloc(mem_ctx, stored_lanman->hash, MIN(8, user_sess_key->length)); } 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, because 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 (!lanman_auth) { DEBUG(3,("ntlm_password_check: Lanman passwords NOT PERMITTED for user %s\n", username)); } else if (!stored_lanman) { DEBUG(3,("ntlm_password_check: NO LanMan password set for user %s (and no NT password supplied)\n", username)); } else if (strchr_m(username, '@')) { DEBUG(3,("ntlm_password_check: NO LanMan password allowed for username@realm logins (user: %s)\n", username)); } else { DEBUG(4,("ntlm_password_check: Checking LM password\n")); if (smb_pwd_check_ntlmv1(mem_ctx, lm_response, stored_lanman->hash, 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 (lanman_auth && stored_lanman) { uint8_t first_8_lm_hash[16]; memcpy(first_8_lm_hash, stored_lanman->hash, 8); memset(first_8_lm_hash + 8, '\0', 8); *user_sess_key = data_blob_talloc(mem_ctx, first_8_lm_hash, 16); *lm_sess_key = data_blob_talloc(mem_ctx, stored_lanman->hash, 8); } return NT_STATUS_OK; } } if (!stored_nt) { 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(mem_ctx, lm_response, stored_nt->hash, challenge, client_username, client_domain, false, &tmp_sess_key)) { if (nt_response->length > 24) { /* If NTLMv2 authentication has preceeded us * (even if it failed), then use the session * key from that. See the RPC-SAMLOGON * torture test */ smb_sess_key_ntlmv2(mem_ctx, nt_response, stored_nt->hash, challenge, client_username, client_domain, false, user_sess_key); } else { /* Otherwise, use the LMv2 session key */ *user_sess_key = tmp_sess_key; } if (user_sess_key->length) { *lm_sess_key = data_blob_talloc(mem_ctx, user_sess_key->data, MIN(8, user_sess_key->length)); } return NT_STATUS_OK; } DEBUG(4,("ntlm_password_check: Checking LMv2 password with upper-cased version of domain %s\n", client_domain)); if (smb_pwd_check_ntlmv2(mem_ctx, lm_response, stored_nt->hash, challenge, client_username, client_domain, true, &tmp_sess_key)) { if (nt_response->length > 24) { /* If NTLMv2 authentication has preceeded us * (even if it failed), then use the session * key from that. See the RPC-SAMLOGON * torture test */ smb_sess_key_ntlmv2(mem_ctx, nt_response, stored_nt->hash, challenge, client_username, client_domain, true, user_sess_key); } else { /* Otherwise, use the LMv2 session key */ *user_sess_key = tmp_sess_key; } if (user_sess_key->length) { *lm_sess_key = data_blob_talloc(mem_ctx, user_sess_key->data, MIN(8, user_sess_key->length)); } return NT_STATUS_OK; } DEBUG(4,("ntlm_password_check: Checking LMv2 password without a domain\n")); if (smb_pwd_check_ntlmv2(mem_ctx, lm_response, stored_nt->hash, challenge, client_username, "", false, &tmp_sess_key)) { if (nt_response->length > 24) { /* If NTLMv2 authentication has preceeded us * (even if it failed), then use the session * key from that. See the RPC-SAMLOGON * torture test */ smb_sess_key_ntlmv2(mem_ctx, nt_response, stored_nt->hash, challenge, client_username, "", false, user_sess_key); } else { /* Otherwise, use the LMv2 session key */ *user_sess_key = tmp_sess_key; } if (user_sess_key->length) { *lm_sess_key = data_blob_talloc(mem_ctx, user_sess_key->data, MIN(8, user_sess_key->length)); } 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 (ntlm_auth) { if (smb_pwd_check_ntlmv1(mem_ctx, lm_response, stored_nt->hash, 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 (lanman_auth && stored_lanman) { uint8_t first_8_lm_hash[16]; memcpy(first_8_lm_hash, stored_lanman->hash, 8); memset(first_8_lm_hash + 8, '\0', 8); *user_sess_key = data_blob_talloc(mem_ctx, first_8_lm_hash, 16); *lm_sess_key = data_blob_talloc(mem_ctx, stored_lanman->hash, 8); } 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)); } /* Try and match error codes */ if (strchr_m(username, '@')) { return NT_STATUS_NOT_FOUND; } return NT_STATUS_WRONG_PASSWORD; }