diff options
Diffstat (limited to 'libcli/auth/ntlm_check.c')
| -rw-r--r-- | libcli/auth/ntlm_check.c | 648 |
1 files changed, 648 insertions, 0 deletions
diff --git a/libcli/auth/ntlm_check.c b/libcli/auth/ntlm_check.c new file mode 100644 index 0000000..cb4be7f --- /dev/null +++ b/libcli/auth/ntlm_check.c @@ -0,0 +1,648 @@ +/* + 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/md4.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]; + int rc; + bool ok; + + if (part_passwd == NULL) { + DEBUG(10,("No password set - DISALLOWING access\n")); + /* No password set - always false ! */ + return false; + } + + if (sec_blob->length != 8) { + DBG_ERR("incorrect challenge size (%zu)\n", sec_blob->length); + return false; + } + + if (nt_response->length != 24) { + DBG_ERR("incorrect password length (%zu)\n", + nt_response->length); + return false; + } + + rc = SMBOWFencrypt(part_passwd, sec_blob->data, p24); + if (rc != 0) { + return false; + } + +#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 + ok = mem_equal_const_time(p24, nt_response->data, 24); + if (!ok) { + return false; + } + if (user_sess_key != NULL) { + *user_sess_key = data_blob_talloc(mem_ctx, NULL, 16); + if (user_sess_key->data == NULL) { + DBG_ERR("data_blob_talloc failed\n"); + return false; + } + SMBsesskeygen_ntv1(part_passwd, user_sess_key->data); + } + return true; +} + +/**************************************************************************** + 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, + 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; + NTSTATUS status; + bool ok; + + if (part_passwd == NULL) { + DEBUG(10,("No password set - DISALLOWING access\n")); + /* No password set - always false */ + return false; + } + + if (sec_blob->length != 8) { + DBG_ERR("incorrect challenge size (%zu)\n", 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. */ + DBG_ERR("incorrect password length (%zu)\n", + 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, kr)) { + return false; + } + + status = SMBOWFencrypt_ntv2(kr, + sec_blob, + &client_key_data, + value_from_encryption); + if (!NT_STATUS_IS_OK(status)) { + return false; + } + +#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); + + ok = mem_equal_const_time(value_from_encryption, ntv2_response->data, 16); + if (!ok) { + return false; + } + if (user_sess_key != NULL) { + *user_sess_key = data_blob_talloc(mem_ctx, NULL, 16); + if (user_sess_key->data == NULL) { + DBG_ERR("data_blob_talloc failed\n"); + return false; + } + + status = SMBsesskeygen_ntv2( + kr, value_from_encryption, user_sess_key->data); + if (!NT_STATUS_IS_OK(status)) { + return false; + } + } + return true; +} + +/**************************************************************************** + 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, + 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; + NTSTATUS status; + + if (part_passwd == NULL) { + DEBUG(10,("No password set - DISALLOWING access\n")); + /* No password set - always false */ + return false; + } + + if (sec_blob->length != 8) { + DBG_ERR("incorrect challenge size (%zu)\n", 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. */ + DBG_ERR("incorrect password length (%zu)\n", + 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, kr)) { + return false; + } + + status = SMBOWFencrypt_ntv2(kr, + sec_blob, + &client_key_data, + value_from_encryption); + if (!NT_STATUS_IS_OK(status)) { + return false; + } + *user_sess_key = data_blob_talloc(mem_ctx, NULL, 16); + if (user_sess_key->data == NULL) { + DBG_ERR("data_blob_talloc failed\n"); + return false; + } + status = SMBsesskeygen_ntv2(kr, + value_from_encryption, + user_sess_key->data); + if (!NT_STATUS_IS_OK(status)) { + return false; + } + 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,("hash_password_check: NO NT password stored for user %s.\n", + username)); + } + + if (client_nt && stored_nt) { + if (mem_equal_const_time(client_nt->hash, stored_nt->hash, sizeof(stored_nt->hash))) { + return NT_STATUS_OK; + } else { + DEBUG(3,("hash_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,("hash_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 (mem_equal_const_time(client_lanman->hash, stored_lanman->hash, sizeof(stored_lanman->hash))) { + return NT_STATUS_OK; + } else { + DEBUG(3,("hash_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, + enum ntlm_auth_level 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) +{ + DATA_BLOB tmp_sess_key; + const char *upper_client_domain = NULL; + + if (ntlm_auth == NTLM_AUTH_DISABLED) { + DBG_WARNING("ntlm_password_check: NTLM authentication not " + "permitted by configuration.\n"); + return NT_STATUS_NTLM_BLOCKED; + } + + if (client_domain != NULL) { + upper_client_domain = talloc_strdup_upper(mem_ctx, client_domain); + if (upper_client_domain == NULL) { + return NT_STATUS_NO_MEMORY; + } + } + + 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 == 8 + && (all_zero(challenge->data, challenge->length))) { + struct samr_Password client_nt; + struct samr_Password client_lm; + char *unix_pw = NULL; + bool lm_ok; + size_t converted_size = 0; + + 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, &converted_size))) { + 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) { + DBG_NOTICE("invalid NT password length (%zu) for user %s\n", + 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 ? client_domain : "<NULL>")); + if (smb_pwd_check_ntlmv2(mem_ctx, + nt_response, + stored_nt->hash, challenge, + client_username, + client_domain, + 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", + upper_client_domain ? upper_client_domain : "<NULL>")); + if (smb_pwd_check_ntlmv2(mem_ctx, + nt_response, + stored_nt->hash, challenge, + client_username, + upper_client_domain, + 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, + "", + 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 == NTLM_AUTH_ON + || (ntlm_auth == NTLM_AUTH_MSCHAPv2_NTLMV2_ONLY && (logon_parameters & MSV1_0_ALLOW_MSVCHAPV2))) { + /* 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) { + DBG_NOTICE("invalid LanMan password length (%zu) for " + "user %s\n", + 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 ? client_domain : "<NULL>")); + if (smb_pwd_check_ntlmv2(mem_ctx, + lm_response, + stored_nt->hash, challenge, + client_username, + client_domain, + &tmp_sess_key)) { + if (nt_response->length > 24) { + /* If NTLMv2 authentication has preceded 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, + 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", + upper_client_domain ? upper_client_domain : "<NULL>")); + if (smb_pwd_check_ntlmv2(mem_ctx, + lm_response, + stored_nt->hash, challenge, + client_username, + upper_client_domain, + &tmp_sess_key)) { + if (nt_response->length > 24) { + /* If NTLMv2 authentication has preceded 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, + upper_client_domain, + 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, + "", + &tmp_sess_key)) { + if (nt_response->length > 24) { + /* If NTLMv2 authentication has preceded 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, + "", + 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 == NTLM_AUTH_ON) { + 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; +} + |