diff options
Diffstat (limited to 'libcli/auth/smbencrypt.c')
| -rw-r--r-- | libcli/auth/smbencrypt.c | 1325 |
1 files changed, 1325 insertions, 0 deletions
diff --git a/libcli/auth/smbencrypt.c b/libcli/auth/smbencrypt.c new file mode 100644 index 0000000..8492202 --- /dev/null +++ b/libcli/auth/smbencrypt.c @@ -0,0 +1,1325 @@ +/* + Unix SMB/CIFS implementation. + SMB parameters and setup + Copyright (C) Andrew Tridgell 1992-1998 + Modified by Jeremy Allison 1995. + Copyright (C) Jeremy Allison 1995-2000. + Copyright (C) Luke Kennethc Casson Leighton 1996-2000. + 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" +#include "system/time.h" +#include "../libcli/auth/msrpc_parse.h" +#include "../lib/crypto/crypto.h" +#include "../libcli/auth/libcli_auth.h" +#include "../librpc/gen_ndr/ndr_ntlmssp.h" +#include "lib/util/bytearray.h" + +#include "lib/crypto/gnutls_helpers.h" +#include <gnutls/gnutls.h> +#include <gnutls/crypto.h> + +int SMBencrypt_hash(const uint8_t lm_hash[16], const uint8_t *c8, uint8_t p24[24]) +{ + uint8_t p21[21]; + int rc; + + memset(p21,'\0',21); + memcpy(p21, lm_hash, 16); + + rc = SMBOWFencrypt(p21, c8, p24); + +#ifdef DEBUG_PASSWORD + DEBUG(100,("SMBencrypt_hash: lm#, challenge, response\n")); + dump_data(100, p21, 16); + dump_data(100, c8, 8); + dump_data(100, p24, 24); +#endif + + return rc; +} + +/* + This implements the X/Open SMB password encryption + It takes a password ('unix' string), a 8 byte "crypt key" + and puts 24 bytes of encrypted password into p24 + + Returns False if password must have been truncated to create LM hash +*/ + +bool SMBencrypt(const char *passwd, const uint8_t *c8, uint8_t p24[24]) +{ + bool ret; + uint8_t lm_hash[16]; + int rc; + + ret = E_deshash(passwd, lm_hash); + rc = SMBencrypt_hash(lm_hash, c8, p24); + if (rc != 0) { + ret = false; + } + return ret; +} + +/** + * Creates the MD4 Hash of the users password in NT UNICODE. + * @param passwd password in 'unix' charset. + * @param p16 return password hashed with md4, caller allocated 16 byte buffer + */ + +bool E_md4hash(const char *passwd, uint8_t p16[16]) +{ + size_t len; + smb_ucs2_t *wpwd; + bool ret; + + ret = push_ucs2_talloc(NULL, &wpwd, passwd, &len); + if (!ret || len < 2) { + /* We don't want to return fixed data, as most callers + * don't check */ + mdfour(p16, (const uint8_t *)passwd, strlen(passwd)); + return false; + } + + len -= 2; + mdfour(p16, (const uint8_t *)wpwd, len); + + talloc_free(wpwd); + return true; +} + +/** + * Creates the DES forward-only Hash of the users password in DOS ASCII charset + * @param passwd password in 'unix' charset. + * @param p16 return password hashed with DES, caller allocated 16 byte buffer + * @return false if password was > 14 characters, and therefore may be incorrect, otherwise true + * @note p16 is filled in regardless + */ + +bool E_deshash(const char *passwd, uint8_t p16[16]) +{ + bool ret; + int rc; + uint8_t dospwd[14]; + TALLOC_CTX *frame = talloc_stackframe(); + + size_t converted_size; + + char *tmpbuf; + + ZERO_STRUCT(dospwd); + + tmpbuf = strupper_talloc(frame, passwd); + if (tmpbuf == NULL) { + /* Too many callers don't check this result, we need to fill in the buffer with something */ + strlcpy((char *)dospwd, passwd ? passwd : "", sizeof(dospwd)); + E_P16(dospwd, p16); + talloc_free(frame); + return false; + } + + ZERO_STRUCT(dospwd); + + ret = convert_string_error(CH_UNIX, CH_DOS, tmpbuf, strlen(tmpbuf), dospwd, sizeof(dospwd), &converted_size); + talloc_free(frame); + + /* Only the first 14 chars are considered, password need not + * be null terminated. We do this in the error and success + * case to avoid returning a fixed 'password' buffer, but + * callers should not use it when E_deshash returns false */ + + rc = E_P16((const uint8_t *)dospwd, p16); + if (rc != 0) { + ret = false; + } + + ZERO_STRUCT(dospwd); + + return ret; +} + +/** + * Creates the MD4 and DES (LM) Hash of the users password. + * MD4 is of the NT Unicode, DES is of the DOS UPPERCASE password. + * @param passwd password in 'unix' charset. + * @param nt_p16 return password hashed with md4, caller allocated 16 byte buffer + * @param p16 return password hashed with des, caller allocated 16 byte buffer + */ + +/* Does both the NT and LM owfs of a user's password */ +void nt_lm_owf_gen(const char *pwd, uint8_t nt_p16[16], uint8_t p16[16]) +{ + /* Calculate the MD4 hash (NT compatible) of the password */ + memset(nt_p16, '\0', 16); + E_md4hash(pwd, nt_p16); + +#ifdef DEBUG_PASSWORD + DEBUG(100,("nt_lm_owf_gen: pwd, nt#\n")); + dump_data(120, (const uint8_t *)pwd, strlen(pwd)); + dump_data(100, nt_p16, 16); +#endif + + E_deshash(pwd, (uint8_t *)p16); + +#ifdef DEBUG_PASSWORD + DEBUG(100,("nt_lm_owf_gen: pwd, lm#\n")); + dump_data(120, (const uint8_t *)pwd, strlen(pwd)); + dump_data(100, p16, 16); +#endif +} + +/* Does both the NTLMv2 owfs of a user's password */ +bool ntv2_owf_gen(const uint8_t owf[16], + const char *user_in, const char *domain_in, + uint8_t kr_buf[16]) +{ + smb_ucs2_t *user; + smb_ucs2_t *domain; + size_t user_byte_len; + size_t domain_byte_len; + gnutls_hmac_hd_t hmac_hnd = NULL; + int rc; + bool ok = false; + TALLOC_CTX *mem_ctx = talloc_init("ntv2_owf_gen for %s\\%s", domain_in, user_in); + + if (!mem_ctx) { + return false; + } + + if (!user_in) { + user_in = ""; + } + + if (!domain_in) { + domain_in = ""; + } + + user_in = strupper_talloc(mem_ctx, user_in); + if (user_in == NULL) { + talloc_free(mem_ctx); + return false; + } + + ok = push_ucs2_talloc(mem_ctx, &user, user_in, &user_byte_len ); + if (!ok) { + DEBUG(0, ("push_uss2_talloc() for user failed)\n")); + talloc_free(mem_ctx); + return false; + } + + ok = push_ucs2_talloc(mem_ctx, &domain, domain_in, &domain_byte_len); + if (!ok) { + DEBUG(0, ("push_ucs2_talloc() for domain failed\n")); + talloc_free(mem_ctx); + return false; + } + + SMB_ASSERT(user_byte_len >= 2); + SMB_ASSERT(domain_byte_len >= 2); + + /* We don't want null termination */ + user_byte_len = user_byte_len - 2; + domain_byte_len = domain_byte_len - 2; + + rc = gnutls_hmac_init(&hmac_hnd, + GNUTLS_MAC_MD5, + owf, + 16); + if (rc < 0) { + ok = false; + goto out; + } + + rc = gnutls_hmac(hmac_hnd, user, user_byte_len); + if (rc < 0) { + gnutls_hmac_deinit(hmac_hnd, NULL); + ok = false; + goto out; + } + rc = gnutls_hmac(hmac_hnd, domain, domain_byte_len); + if (rc < 0) { + gnutls_hmac_deinit(hmac_hnd, NULL); + ok = false; + goto out; + } + + gnutls_hmac_deinit(hmac_hnd, kr_buf); + +#ifdef DEBUG_PASSWORD + DEBUG(100, ("ntv2_owf_gen: user, domain, owfkey, kr\n")); + dump_data(100, (uint8_t *)user, user_byte_len); + dump_data(100, (uint8_t *)domain, domain_byte_len); + dump_data(100, owf, 16); + dump_data(100, kr_buf, 16); +#endif + + ok = true; +out: + talloc_free(mem_ctx); + return ok; +} + +/* Does the des encryption from the NT or LM MD4 hash. */ +int SMBOWFencrypt(const uint8_t passwd[16], const uint8_t *c8, uint8_t p24[24]) +{ + uint8_t p21[21]; + + ZERO_STRUCT(p21); + + memcpy(p21, passwd, 16); + return E_P24(p21, c8, p24); +} + +/* Does the des encryption. */ + +int SMBNTencrypt_hash(const uint8_t nt_hash[16], const uint8_t *c8, uint8_t *p24) +{ + uint8_t p21[21]; + int rc; + + memset(p21,'\0',21); + memcpy(p21, nt_hash, 16); + rc = SMBOWFencrypt(p21, c8, p24); + +#ifdef DEBUG_PASSWORD + DEBUG(100,("SMBNTencrypt: nt#, challenge, response\n")); + dump_data(100, p21, 16); + dump_data(100, c8, 8); + dump_data(100, p24, 24); +#endif + + return rc; +} + +/* Does the NT MD4 hash then des encryption. Plaintext version of the above. */ + +int SMBNTencrypt(const char *passwd, const uint8_t *c8, uint8_t *p24) +{ + uint8_t nt_hash[16]; + E_md4hash(passwd, nt_hash); + return SMBNTencrypt_hash(nt_hash, c8, p24); +} + + +/* Does the md5 encryption from the Key Response for NTLMv2. */ +NTSTATUS SMBOWFencrypt_ntv2(const uint8_t kr[16], + const DATA_BLOB *srv_chal, + const DATA_BLOB *smbcli_chal, + uint8_t resp_buf[16]) +{ + gnutls_hmac_hd_t hmac_hnd = NULL; + NTSTATUS status; + int rc; + + rc = gnutls_hmac_init(&hmac_hnd, + GNUTLS_MAC_MD5, + kr, + 16); + if (rc < 0) { + return gnutls_error_to_ntstatus(rc, NT_STATUS_HMAC_NOT_SUPPORTED); + } + + rc = gnutls_hmac(hmac_hnd, srv_chal->data, srv_chal->length); + if (rc < 0) { + status = gnutls_error_to_ntstatus(rc, NT_STATUS_HMAC_NOT_SUPPORTED); + goto out; + } + rc = gnutls_hmac(hmac_hnd, smbcli_chal->data, smbcli_chal->length); + if (rc < 0) { + status = gnutls_error_to_ntstatus(rc, NT_STATUS_HMAC_NOT_SUPPORTED); + goto out; + } + +#ifdef DEBUG_PASSWORD + DEBUG(100, ("SMBOWFencrypt_ntv2: srv_chal, smbcli_chal, resp_buf\n")); + dump_data(100, srv_chal->data, srv_chal->length); + dump_data(100, smbcli_chal->data, smbcli_chal->length); + dump_data(100, resp_buf, 16); +#endif + + status = NT_STATUS_OK; +out: + gnutls_hmac_deinit(hmac_hnd, resp_buf); + return status; +} + +NTSTATUS SMBsesskeygen_ntv2(const uint8_t kr[16], + const uint8_t *nt_resp, + uint8_t sess_key[16]) +{ + int rc; + + /* a very nice, 128 bit, variable session key */ + rc = gnutls_hmac_fast(GNUTLS_MAC_MD5, + kr, + 16, + nt_resp, + 16, + sess_key); + if (rc != 0) { + return gnutls_error_to_ntstatus(rc, NT_STATUS_HASH_NOT_SUPPORTED); + } + +#ifdef DEBUG_PASSWORD + DEBUG(100, ("SMBsesskeygen_ntv2:\n")); + dump_data(100, sess_key, 16); +#endif + + return NT_STATUS_OK; +} + +void SMBsesskeygen_ntv1(const uint8_t kr[16], uint8_t sess_key[16]) +{ + /* yes, this session key does not change - yes, this + is a problem - but it is 128 bits */ + + mdfour((uint8_t *)sess_key, kr, 16); + +#ifdef DEBUG_PASSWORD + DEBUG(100, ("SMBsesskeygen_ntv1:\n")); + dump_data(100, sess_key, 16); +#endif +} + +NTSTATUS SMBsesskeygen_lm_sess_key(const uint8_t lm_hash[16], + const uint8_t lm_resp[24], /* only uses 8 */ + uint8_t sess_key[16]) +{ + /* Calculate the LM session key (effective length 40 bits, + but changes with each session) */ + uint8_t p24[24]; + uint8_t partial_lm_hash[14]; + int rc; + + memcpy(partial_lm_hash, lm_hash, 8); + memset(partial_lm_hash + 8, 0xbd, 6); + + rc = des_crypt56_gnutls(p24, lm_resp, partial_lm_hash, SAMBA_GNUTLS_ENCRYPT); + if (rc < 0) { + return gnutls_error_to_ntstatus(rc, NT_STATUS_ACCESS_DISABLED_BY_POLICY_OTHER); + } + rc = des_crypt56_gnutls(p24+8, lm_resp, partial_lm_hash + 7, SAMBA_GNUTLS_ENCRYPT); + if (rc < 0) { + return gnutls_error_to_ntstatus(rc, NT_STATUS_ACCESS_DISABLED_BY_POLICY_OTHER); + } + + memcpy(sess_key, p24, 16); + +#ifdef DEBUG_PASSWORD + DEBUG(100, ("SMBsesskeygen_lm_sess_key: \n")); + dump_data(100, sess_key, 16); +#endif + + return NT_STATUS_OK; +} + +DATA_BLOB NTLMv2_generate_names_blob(TALLOC_CTX *mem_ctx, + const char *hostname, + const char *domain) +{ + DATA_BLOB names_blob = data_blob_talloc(mem_ctx, NULL, 0); + + /* Deliberately ignore return here.. */ + if (hostname != NULL) { + (void)msrpc_gen(mem_ctx, &names_blob, + "aaa", + MsvAvNbDomainName, domain, + MsvAvNbComputerName, hostname, + MsvAvEOL, ""); + } else { + (void)msrpc_gen(mem_ctx, &names_blob, + "aa", + MsvAvNbDomainName, domain, + MsvAvEOL, ""); + } + return names_blob; +} + +static DATA_BLOB NTLMv2_generate_client_data(TALLOC_CTX *mem_ctx, + NTTIME nttime, + const DATA_BLOB *names_blob) +{ + uint8_t client_chal[8]; + DATA_BLOB response = data_blob(NULL, 0); + uint8_t long_date[8]; + + generate_random_buffer(client_chal, sizeof(client_chal)); + + push_nttime(long_date, 0, nttime); + + /* See http://www.ubiqx.org/cifs/SMB.html#SMB.8.5 */ + + /* Deliberately ignore return here.. */ + (void)msrpc_gen(mem_ctx, &response, "ddbbdb", + 0x00000101, /* Header */ + 0, /* 'Reserved' */ + long_date, 8, /* Timestamp */ + client_chal, 8, /* client challenge */ + 0, /* Unknown */ + names_blob->data, names_blob->length); /* End of name list */ + + return response; +} + +static DATA_BLOB NTLMv2_generate_response(TALLOC_CTX *out_mem_ctx, + const uint8_t ntlm_v2_hash[16], + const DATA_BLOB *server_chal, + NTTIME nttime, + const DATA_BLOB *names_blob) +{ + uint8_t ntlmv2_response[16]; + DATA_BLOB ntlmv2_client_data; + DATA_BLOB final_response; + NTSTATUS status; + + TALLOC_CTX *mem_ctx = talloc_named(out_mem_ctx, 0, + "NTLMv2_generate_response internal context"); + + if (!mem_ctx) { + return data_blob(NULL, 0); + } + + /* NTLMv2 */ + /* generate some data to pass into the response function - including + the hostname and domain name of the server */ + ntlmv2_client_data = NTLMv2_generate_client_data(mem_ctx, nttime, names_blob); + + /* Given that data, and the challenge from the server, generate a response */ + status = SMBOWFencrypt_ntv2(ntlm_v2_hash, + server_chal, + &ntlmv2_client_data, + ntlmv2_response); + if (!NT_STATUS_IS_OK(status)) { + talloc_free(mem_ctx); + return data_blob(NULL, 0); + } + + final_response = data_blob_talloc(out_mem_ctx, NULL, sizeof(ntlmv2_response) + ntlmv2_client_data.length); + + memcpy(final_response.data, ntlmv2_response, sizeof(ntlmv2_response)); + + memcpy(final_response.data+sizeof(ntlmv2_response), + ntlmv2_client_data.data, ntlmv2_client_data.length); + + talloc_free(mem_ctx); + + return final_response; +} + +static DATA_BLOB LMv2_generate_response(TALLOC_CTX *mem_ctx, + const uint8_t ntlm_v2_hash[16], + const DATA_BLOB *server_chal) +{ + uint8_t lmv2_response[16]; + DATA_BLOB lmv2_client_data = data_blob_talloc(mem_ctx, NULL, 8); + DATA_BLOB final_response = data_blob_talloc(mem_ctx, NULL,24); + NTSTATUS status; + + /* LMv2 */ + /* client-supplied random data */ + generate_random_buffer(lmv2_client_data.data, lmv2_client_data.length); + + /* Given that data, and the challenge from the server, generate a response */ + status = SMBOWFencrypt_ntv2(ntlm_v2_hash, + server_chal, + &lmv2_client_data, + lmv2_response); + if (!NT_STATUS_IS_OK(status)) { + data_blob_free(&lmv2_client_data); + return data_blob(NULL, 0); + } + memcpy(final_response.data, lmv2_response, sizeof(lmv2_response)); + + /* after the first 16 bytes is the random data we generated above, + so the server can verify us with it */ + memcpy(final_response.data+sizeof(lmv2_response), + lmv2_client_data.data, lmv2_client_data.length); + + data_blob_free(&lmv2_client_data); + + return final_response; +} + +bool SMBNTLMv2encrypt_hash(TALLOC_CTX *mem_ctx, + const char *user, const char *domain, const uint8_t nt_hash[16], + const DATA_BLOB *server_chal, + const NTTIME *server_timestamp, + const DATA_BLOB *names_blob, + DATA_BLOB *lm_response, DATA_BLOB *nt_response, + DATA_BLOB *lm_session_key, DATA_BLOB *user_session_key) +{ + uint8_t ntlm_v2_hash[16]; + NTSTATUS status; + + /* We don't use the NT# directly. Instead we use it mashed up with + the username and domain. + This prevents username swapping during the auth exchange + */ + if (!ntv2_owf_gen(nt_hash, user, domain, ntlm_v2_hash)) { + return false; + } + + if (nt_response) { + const NTTIME *nttime = server_timestamp; + NTTIME _now = 0; + + if (nttime == NULL) { + struct timeval tv_now = timeval_current(); + _now = timeval_to_nttime(&tv_now); + nttime = &_now; + } + + *nt_response = NTLMv2_generate_response(mem_ctx, + ntlm_v2_hash, + server_chal, + *nttime, + names_blob); + if (user_session_key) { + *user_session_key = data_blob_talloc(mem_ctx, NULL, 16); + + /* The NTLMv2 calculations also provide a session key, for signing etc later */ + /* use only the first 16 bytes of nt_response for session key */ + status = SMBsesskeygen_ntv2(ntlm_v2_hash, + nt_response->data, + user_session_key->data); + if (!NT_STATUS_IS_OK(status)) { + return false; + } + } + } + + /* LMv2 */ + + if (lm_response) { + if (server_timestamp != NULL) { + *lm_response = data_blob_talloc_zero(mem_ctx, 24); + } else { + *lm_response = LMv2_generate_response(mem_ctx, + ntlm_v2_hash, + server_chal); + } + if (lm_session_key) { + *lm_session_key = data_blob_talloc(mem_ctx, NULL, 16); + + /* The NTLMv2 calculations also provide a session key, for signing etc later */ + /* use only the first 16 bytes of lm_response for session key */ + status = SMBsesskeygen_ntv2(ntlm_v2_hash, + lm_response->data, + lm_session_key->data); + if (!NT_STATUS_IS_OK(status)) { + return false; + } + } + } + + return true; +} + +bool SMBNTLMv2encrypt(TALLOC_CTX *mem_ctx, + const char *user, const char *domain, + const char *password, + const DATA_BLOB *server_chal, + const DATA_BLOB *names_blob, + DATA_BLOB *lm_response, DATA_BLOB *nt_response, + DATA_BLOB *lm_session_key, DATA_BLOB *user_session_key) +{ + uint8_t nt_hash[16]; + E_md4hash(password, nt_hash); + + return SMBNTLMv2encrypt_hash(mem_ctx, + user, domain, nt_hash, + server_chal, NULL, names_blob, + lm_response, nt_response, lm_session_key, user_session_key); +} + +NTSTATUS NTLMv2_RESPONSE_verify_netlogon_creds(const char *account_name, + const char *account_domain, + const DATA_BLOB response, + const struct netlogon_creds_CredentialState *creds, + const char *workgroup) +{ + TALLOC_CTX *frame = NULL; + /* RespType + HiRespType */ + static const char *magic = "\x01\x01"; + int cmp; + struct NTLMv2_RESPONSE v2_resp; + enum ndr_err_code err; + const struct AV_PAIR *av_nb_cn = NULL; + const struct AV_PAIR *av_nb_dn = NULL; + + if (response.length < 48) { + /* + * NTLMv2_RESPONSE has at least 48 bytes. + */ + return NT_STATUS_OK; + } + + cmp = memcmp(response.data + 16, magic, 2); + if (cmp != 0) { + /* + * It doesn't look like a valid NTLMv2_RESPONSE + */ + return NT_STATUS_OK; + } + + if (response.length == 95) { + /* + * ndr_pull_NTLMv2_RESPONSE() fails on this strange blob, + * because the AvPairs content is not valid + * as AvLen of the first pair is 33032 (0x8108). + * + * I saw a single machine sending the following 3 times + * in a row, but I'm not sure if everything is static. + * + * Note this is NTLMv2_CLIENT_CHALLENGE only, not + * the full NTLMv2_RESPONSE (which has Response of 16 bytes + * before the NTLMv2_CLIENT_CHALLENGE). + * + * Note this code only prevents + * ndr_pull_error(Buffer Size Error): Pull bytes 39016 + * debug message for a known case, the actual + * bug is also handled below in a generic way to + * map NT_STATUS_BUFFER_TOO_SMALL to NT_STATUS_OK. + * + * See https://bugzilla.samba.org/show_bug.cgi?id=14932 + */ + static const char *netapp_magic = + "\x01\x01\x00\x00\x00\x00\x00\x00" + "\x3f\x3f\x3f\x3f\x3f\x3f\x3f\x3f" + "\xb8\x82\x3a\xf1\xb3\xdd\x08\x15" + "\x00\x00\x00\x00\x11\xa2\x08\x81" + "\x50\x38\x22\x78\x2b\x94\x47\xfe" + "\x54\x94\x7b\xff\x17\x27\x5a\xb4" + "\xf4\x18\xba\xdc\x2c\x38\xfd\x5b" + "\xfb\x0e\xc1\x85\x1e\xcc\x92\xbb" + "\x9b\xb1\xc4\xd5\x53\x14\xff\x8c" + "\x76\x49\xf5\x45\x90\x19\xa2"; + /* + * First we check the initial bytes + * and the 0x3F timestamp. + */ + cmp = memcmp(response.data + 16, + netapp_magic, + 16); + if (cmp == 0) { + /* + * Then check everything after the + * client challenge + */ + cmp = memcmp(response.data + 40, + netapp_magic + 24, + response.length - 40); + if (cmp == 0) { + DBG_DEBUG("Invalid NETAPP NTLMv2_RESPONSE " + "for user[%s\\%s] against " + "SEC_CHAN(%u)[%s/%s] " + "in workgroup[%s]\n", + account_domain, + account_name, + creds->secure_channel_type, + creds->computer_name, + creds->account_name, + workgroup); + return NT_STATUS_OK; + } + } + } + + frame = talloc_stackframe(); + + err = ndr_pull_struct_blob(&response, frame, &v2_resp, + (ndr_pull_flags_fn_t)ndr_pull_NTLMv2_RESPONSE); + if (!NDR_ERR_CODE_IS_SUCCESS(err)) { + NTSTATUS status; + status = ndr_map_error2ntstatus(err); + if (NT_STATUS_EQUAL(status, NT_STATUS_BUFFER_TOO_SMALL)) { + /* + * We are supposed to ignore invalid buffers, + * see https://bugzilla.samba.org/show_bug.cgi?id=14932 + */ + status = NT_STATUS_OK; + } + DEBUG(2,("%s: Failed to parse NTLMv2_RESPONSE length=%u " + "for user[%s\\%s] against SEC_CHAN(%u)[%s/%s] " + "in workgroup[%s] - %s %s %s\n", + __func__, + (unsigned)response.length, + account_domain, + account_name, + creds->secure_channel_type, + creds->computer_name, + creds->account_name, + workgroup, + ndr_map_error2string(err), + NT_STATUS_IS_OK(status) ? "(ignoring) =>" : "=>", + nt_errstr(status))); + dump_data(2, response.data, response.length); + TALLOC_FREE(frame); + return status; + } + + if (DEBUGLVL(10)) { + NDR_PRINT_DEBUG(NTLMv2_RESPONSE, &v2_resp); + } + + /* + * Make sure the netbios computer name in the + * NTLMv2_RESPONSE matches the computer name + * in the secure channel credentials for workstation + * trusts. + * + * And the netbios domain name matches our + * workgroup. + * + * This prevents workstations from requesting + * the session key of NTLMSSP sessions of clients + * to other hosts. + */ + if (creds->secure_channel_type == SEC_CHAN_WKSTA) { + av_nb_cn = ndr_ntlmssp_find_av(&v2_resp.Challenge.AvPairs, + MsvAvNbComputerName); + av_nb_dn = ndr_ntlmssp_find_av(&v2_resp.Challenge.AvPairs, + MsvAvNbDomainName); + } + + if (av_nb_cn != NULL) { + const char *v = NULL; + char *a = NULL; + size_t len; + + v = av_nb_cn->Value.AvNbComputerName; + + a = talloc_strdup(frame, creds->account_name); + if (a == NULL) { + TALLOC_FREE(frame); + return NT_STATUS_NO_MEMORY; + } + len = strlen(a); + if (len > 0 && a[len - 1] == '$') { + a[len - 1] = '\0'; + } + + cmp = strcasecmp_m(a, v); + if (cmp != 0) { + DEBUG(2,("%s: NTLMv2_RESPONSE with " + "NbComputerName[%s] rejected " + "for user[%s\\%s] " + "against SEC_CHAN_WKSTA[%s/%s] " + "in workgroup[%s]\n", + __func__, v, + account_domain, + account_name, + creds->computer_name, + creds->account_name, + workgroup)); + TALLOC_FREE(frame); + return NT_STATUS_LOGON_FAILURE; + } + } + if (av_nb_dn != NULL) { + const char *v = NULL; + + v = av_nb_dn->Value.AvNbDomainName; + + cmp = strcasecmp_m(workgroup, v); + if (cmp != 0) { + DEBUG(2,("%s: NTLMv2_RESPONSE with " + "NbDomainName[%s] rejected " + "for user[%s\\%s] " + "against SEC_CHAN_WKSTA[%s/%s] " + "in workgroup[%s]\n", + __func__, v, + account_domain, + account_name, + creds->computer_name, + creds->account_name, + workgroup)); + TALLOC_FREE(frame); + return NT_STATUS_LOGON_FAILURE; + } + } + + TALLOC_FREE(frame); + return NT_STATUS_OK; +} + +enum encode_order { + ENCODE_ORDER_PASSWORD_FIRST, + ENCODE_ORDER_PASSWORD_LAST, +}; + +#define PASSWORD_BUFFER_LEN 512 + +static ssize_t _encode_pwd_buffer_from_str(uint8_t buf[PASSWORD_BUFFER_LEN], + const char *password, + int string_flags, + enum encode_order order) +{ + ssize_t new_pw_len; + size_t pw_pos = 0; + size_t random_pos = 0; + size_t random_len = 0; + + /* The incoming buffer can be any alignment. */ + string_flags |= STR_NOALIGN; + + new_pw_len = push_string(buf, + password, + PASSWORD_BUFFER_LEN, + string_flags); + if (new_pw_len < 0) { + BURN_DATA_SIZE(buf, PASSWORD_BUFFER_LEN); + return -1; + } + + if (new_pw_len == PASSWORD_BUFFER_LEN) { + return new_pw_len; + } + + switch (order) { + case ENCODE_ORDER_PASSWORD_FIRST: + pw_pos = 0; + random_pos = new_pw_len; + random_len = PASSWORD_BUFFER_LEN - random_pos; + break; + case ENCODE_ORDER_PASSWORD_LAST: + pw_pos = PASSWORD_BUFFER_LEN - new_pw_len; + random_pos = 0; + random_len = pw_pos; + memmove(buf + pw_pos, buf, new_pw_len); + break; + } + + generate_random_buffer(buf + random_pos, random_len); + + return new_pw_len; +} + +/*********************************************************** + encode a password buffer with a unicode password. The buffer + is filled with random data to make it harder to attack. +************************************************************/ +bool encode_pw_buffer(uint8_t buffer[516], const char *password, int string_flags) +{ + ssize_t pw_len; + + pw_len = _encode_pwd_buffer_from_str(buffer, + password, + string_flags, + ENCODE_ORDER_PASSWORD_LAST); + if (pw_len < 0 || pw_len > PASSWORD_BUFFER_LEN) { + return false; + } + + PUSH_LE_U32(buffer, PASSWORD_BUFFER_LEN, pw_len); + + return true; +} + + +/*********************************************************** + decode a password buffer + *new_pw_len is the length in bytes of the possibly mulitbyte + returned password including termination. +************************************************************/ + +bool decode_pw_buffer(TALLOC_CTX *ctx, + uint8_t in_buffer[516], + char **pp_new_pwrd, + size_t *new_pw_len, + charset_t string_charset) +{ + DATA_BLOB new_password; + int byte_len=0; + bool ok; + + *pp_new_pwrd = NULL; + *new_pw_len = 0; + + ok = extract_pw_from_buffer(ctx, in_buffer, &new_password); + if (!ok) { + return false; + } + + /* + Warning !!! : This function is called from some rpc call. + The password IN the buffer may be a UNICODE string. + The password IN new_pwrd is an ASCII string + If you reuse that code somewhere else check first. + */ + + /* decode into the return buffer. */ + ok = convert_string_talloc(ctx, + string_charset, + CH_UNIX, + new_password.data, + new_password.length, + (void *)pp_new_pwrd, + new_pw_len); + data_blob_free(&new_password); + if (!ok) { + DBG_ERR("Failed to convert incoming password\n"); + return false; + } + talloc_keep_secret(*pp_new_pwrd); + +#ifdef DEBUG_PASSWORD + DEBUG(100,("decode_pw_buffer: new_pwrd: ")); + dump_data(100, (uint8_t *)*pp_new_pwrd, *new_pw_len); + DEBUG(100,("multibyte len:%lu\n", (unsigned long int)*new_pw_len)); + DEBUG(100,("original char len:%d\n", byte_len/2)); +#endif + + return true; +} + +#define MAX_PASSWORD_LEN 256 + +/* + * [MS-SAMR] 2.2.6.32 This creates the buffer to be sent. It is of type + * SAMPR_USER_PASSWORD_AES. + */ +bool encode_pwd_buffer514_from_str(uint8_t buffer[514], + const char *password, + uint32_t string_flags) +{ + ssize_t pw_len; + + pw_len = _encode_pwd_buffer_from_str(buffer + 2, + password, + string_flags, + ENCODE_ORDER_PASSWORD_FIRST); + if (pw_len < 0) { + return false; + } + + PUSH_LE_U16(buffer, 0, pw_len); + + return true; +} + +bool extract_pwd_blob_from_buffer514(TALLOC_CTX *mem_ctx, + const uint8_t in_buffer[514], + DATA_BLOB *new_password) +{ +#ifdef DEBUG_PASSWORD + DEBUG(100, ("in_buffer: ")); + dump_data(100, in_buffer, 514); +#endif + + new_password->length = PULL_LE_U16(in_buffer, 0); + if (new_password->length == 0 || new_password->length > 512) { + return false; + } + + new_password->data = + talloc_memdup(mem_ctx, in_buffer + 2, new_password->length); + if (new_password->data == NULL) { + return false; + } + talloc_keep_secret(new_password->data); + +#ifdef DEBUG_PASSWORD + DEBUG(100, ("new_pwd_len: %zu\n", new_password->length)); + DEBUG(100, ("new_pwd: ")); + dump_data(100, new_password->data, new_password->length); +#endif + + return true; +} + +bool decode_pwd_string_from_buffer514(TALLOC_CTX *mem_ctx, + const uint8_t in_buffer[514], + charset_t string_charset, + DATA_BLOB *decoded_password) +{ + DATA_BLOB new_password = { + .length = 0, + }; + bool ok; + + ok = extract_pwd_blob_from_buffer514(mem_ctx, in_buffer, &new_password); + if (!ok) { + return false; + } + + ok = convert_string_talloc(mem_ctx, + string_charset, + CH_UNIX, + new_password.data, + new_password.length, + (void *)&decoded_password->data, + &decoded_password->length); + data_blob_free(&new_password); + if (!ok) { + return false; + } + talloc_keep_secret(decoded_password->data); + + return true; +} + +/*********************************************************** + Encode an arc4 password change buffer. +************************************************************/ +NTSTATUS encode_rc4_passwd_buffer(const char *passwd, + const DATA_BLOB *session_key, + struct samr_CryptPasswordEx *out_crypt_pwd) +{ + uint8_t _confounder[16] = {0}; + DATA_BLOB confounder = data_blob_const(_confounder, 16); + DATA_BLOB pw_data = data_blob_const(out_crypt_pwd->data, 516); + bool ok; + int rc; + + ok = encode_pw_buffer(pw_data.data, passwd, STR_UNICODE); + if (!ok) { + return NT_STATUS_INVALID_PARAMETER; + } + + generate_random_buffer(confounder.data, confounder.length); + + rc = samba_gnutls_arcfour_confounded_md5(&confounder, + session_key, + &pw_data, + SAMBA_GNUTLS_ENCRYPT); + if (rc < 0) { + ZERO_ARRAY(_confounder); + data_blob_clear(&pw_data); + return gnutls_error_to_ntstatus(rc, NT_STATUS_ACCESS_DISABLED_BY_POLICY_OTHER); + } + + /* + * The packet format is the 516 byte RC4 encrypted + * pasword followed by the 16 byte counfounder + * The confounder is a salt to prevent pre-computed hash attacks on the + * database. + */ + memcpy(&out_crypt_pwd->data[516], confounder.data, confounder.length); + ZERO_ARRAY(_confounder); + + return NT_STATUS_OK; +} + +/*********************************************************** + Decode an arc4 encrypted password change buffer. +************************************************************/ + +NTSTATUS decode_rc4_passwd_buffer(const DATA_BLOB *psession_key, + struct samr_CryptPasswordEx *inout_crypt_pwd) +{ + /* Confounder is last 16 bytes. */ + DATA_BLOB confounder = data_blob_const(&inout_crypt_pwd->data[516], 16); + DATA_BLOB pw_data = data_blob_const(&inout_crypt_pwd->data, 516); + int rc; + + rc = samba_gnutls_arcfour_confounded_md5(&confounder, + psession_key, + &pw_data, + SAMBA_GNUTLS_DECRYPT); + if (rc < 0) { + return gnutls_error_to_ntstatus(rc, NT_STATUS_ACCESS_DISABLED_BY_POLICY_OTHER); + } + + return NT_STATUS_OK; +} + +/*********************************************************** + encode a password buffer with an already unicode password. The + rest of the buffer is filled with random data to make it harder to attack. +************************************************************/ + +static bool create_pw_buffer_from_blob(uint8_t buffer[512], + const DATA_BLOB *in_password, + enum encode_order order) +{ + size_t pwd_pos = 0; + size_t random_pos = 0; + size_t random_len = 0; + + if (in_password->length > 512) { + return false; + } + + switch (order) { + case ENCODE_ORDER_PASSWORD_FIRST: + pwd_pos = 0; + random_pos = in_password->length; + break; + case ENCODE_ORDER_PASSWORD_LAST: + pwd_pos = PASSWORD_BUFFER_LEN - in_password->length; + random_pos = 0; + break; + } + random_len = PASSWORD_BUFFER_LEN - in_password->length; + + memcpy(buffer + pwd_pos, in_password->data, in_password->length); + generate_random_buffer(buffer + random_pos, random_len); + + return true; +} + +bool set_pw_in_buffer(uint8_t buffer[516], const DATA_BLOB *password) +{ + bool ok; + + ok = create_pw_buffer_from_blob(buffer, + password, + ENCODE_ORDER_PASSWORD_LAST); + if (!ok) { + return false; + } + + /* + * The length of the new password is in the last 4 bytes of + * the data buffer. + */ + PUSH_LE_U32(buffer, PASSWORD_BUFFER_LEN, password->length); + + return true; +} + +/*********************************************************** + decode a password buffer + *new_pw_size is the length in bytes of the extracted unicode password +************************************************************/ +bool extract_pw_from_buffer(TALLOC_CTX *mem_ctx, + uint8_t in_buffer[516], DATA_BLOB *new_pass) +{ + int byte_len=0; + + /* The length of the new password is in the last 4 bytes of the data buffer. */ + + byte_len = IVAL(in_buffer, 512); + +#ifdef DEBUG_PASSWORD + dump_data(100, in_buffer, 516); +#endif + + /* Password cannot be longer than the size of the password buffer */ + if ( (byte_len < 0) || (byte_len > 512)) { + return false; + } + + *new_pass = data_blob_talloc(mem_ctx, &in_buffer[512 - byte_len], byte_len); + + if (!new_pass->data) { + return false; + } + talloc_keep_secret(new_pass->data); + + return true; +} + + +/* encode a wkssvc_PasswordBuffer: + * + * similar to samr_CryptPasswordEx. Different: 8byte confounder (instead of + * 16byte), confounder in front of the 516 byte buffer (instead of after that + * buffer), calling MD5Update() first with session_key and then with confounder + * (vice versa in samr) - Guenther */ + +WERROR encode_wkssvc_join_password_buffer(TALLOC_CTX *mem_ctx, + const char *pwd, + DATA_BLOB *session_key, + struct wkssvc_PasswordBuffer **out_pwd_buf) +{ + struct wkssvc_PasswordBuffer *pwd_buf = NULL; + uint8_t _confounder[8] = {0}; + DATA_BLOB confounder = data_blob_const(_confounder, 8); + uint8_t pwbuf[516] = {0}; + DATA_BLOB encrypt_pwbuf = data_blob_const(pwbuf, 516); + int rc; + + pwd_buf = talloc_zero(mem_ctx, struct wkssvc_PasswordBuffer); + if (pwd_buf == NULL) { + return WERR_NOT_ENOUGH_MEMORY; + } + + encode_pw_buffer(pwbuf, pwd, STR_UNICODE); + + generate_random_buffer(_confounder, sizeof(_confounder)); + + rc = samba_gnutls_arcfour_confounded_md5(session_key, + &confounder, + &encrypt_pwbuf, + SAMBA_GNUTLS_ENCRYPT); + if (rc < 0) { + ZERO_ARRAY(_confounder); + TALLOC_FREE(pwd_buf); + return gnutls_error_to_werror(rc, WERR_CONTENT_BLOCKED); + } + + memcpy(&pwd_buf->data[0], confounder.data, confounder.length); + ZERO_ARRAY(_confounder); + memcpy(&pwd_buf->data[8], encrypt_pwbuf.data, encrypt_pwbuf.length); + ZERO_ARRAY(pwbuf); + + *out_pwd_buf = pwd_buf; + + return WERR_OK; +} + +WERROR decode_wkssvc_join_password_buffer(TALLOC_CTX *mem_ctx, + struct wkssvc_PasswordBuffer *pwd_buf, + DATA_BLOB *session_key, + char **pwd) +{ + uint8_t _confounder[8] = { 0 }; + DATA_BLOB confounder = data_blob_const(_confounder, 8); + uint8_t pwbuf[516] = {0}; + DATA_BLOB decrypt_pwbuf = data_blob_const(pwbuf, 516); + bool ok; + int rc; + + if (pwd_buf == NULL) { + return WERR_INVALID_PASSWORD; + } + + *pwd = NULL; + + if (session_key->length != 16) { + DEBUG(10,("invalid session key\n")); + return WERR_INVALID_PASSWORD; + } + + confounder = data_blob_const(&pwd_buf->data[0], 8); + memcpy(&pwbuf, &pwd_buf->data[8], 516); + + rc = samba_gnutls_arcfour_confounded_md5(session_key, + &confounder, + &decrypt_pwbuf, + SAMBA_GNUTLS_ENCRYPT); + if (rc < 0) { + ZERO_ARRAY(_confounder); + TALLOC_FREE(pwd_buf); + return gnutls_error_to_werror(rc, WERR_CONTENT_BLOCKED); + } + + ok = decode_pw_buffer(mem_ctx, + decrypt_pwbuf.data, + pwd, + &decrypt_pwbuf.length, + CH_UTF16); + ZERO_ARRAY(pwbuf); + + if (!ok) { + return WERR_INVALID_PASSWORD; + } + + return WERR_OK; +} |