/* * CDDL HEADER START * * The contents of this file are subject to the terms of the * Common Development and Distribution License (the "License"). * You may not use this file except in compliance with the License. * * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE * or http://www.opensolaris.org/os/licensing. * See the License for the specific language governing permissions * and limitations under the License. * * When distributing Covered Code, include this CDDL HEADER in each * file and include the License file at usr/src/OPENSOLARIS.LICENSE. * If applicable, add the following below this CDDL HEADER, with the * fields enclosed by brackets "[]" replaced with your own identifying * information: Portions Copyright [yyyy] [name of copyright owner] * * CDDL HEADER END */ /* * Copyright (c) 2007, 2010, Oracle and/or its affiliates. All rights reserved. * Copyright 2021 Tintri by DDN, Inc. All rights reserved. */ /* * NETR challenge/response client functions. * * NT_STATUS_INVALID_PARAMETER * NT_STATUS_NO_TRUST_SAM_ACCOUNT * NT_STATUS_ACCESS_DENIED */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #define NETR_SESSKEY_ZEROBUF_SZ 4 /* The DES algorithm uses a 56-bit encryption key. */ #define NETR_DESKEY_LEN 7 int netr_setup_authenticator(netr_info_t *, struct netr_authenticator *, struct netr_authenticator *); DWORD netr_validate_chain(netr_info_t *, struct netr_authenticator *); static int netr_server_req_challenge(mlsvc_handle_t *, netr_info_t *); static int netr_server_authenticate2(mlsvc_handle_t *, netr_info_t *); static int netr_gen_password(BYTE *, BYTE *, BYTE *); /* * Shared with netr_logon.c */ netr_info_t netr_global_info = { .use_secure_rpc = B_TRUE, .use_logon_ex = B_TRUE }; extern ndr_auth_ctx_t netr_ssp_ctx; /* * These flags control various parts of NetLogon RPC messages. * The default is 0 - setting a bit disables some feature. * They are set in smbd/netlogon_flags in svc:/network/smb/server. * These are set when smbd starts. Changing them requires * restarting smbd. * * These shouldn't be confused with either SamLogonEx's ExtraFlags, * or NetrServerAuthenticate's negotiate_flags. * * DISABLE_SECURE_RPC causes Netlogon to use unauthenticated RPC. * Note that the underlying transport is still authenticated and signed. * * DISABLE_RESP_VERIF instructs RPC authentication to ignore failures * when verifying responses. * * DISABLE_SAMLOGONEX causes Netlogon to always use SamLogon, which * makes use of Netlogon Authenticators. */ #define NETR_CFG_DISABLE_SECURE_RPC 0x00000001 #define NETR_CFG_DISABLE_RESP_VERIF 0x00000002 #define NETR_CFG_DISABLE_SAMLOGONEX 0x00000004 void netlogon_init_global(uint32_t flags) { netr_global_info.use_secure_rpc = ((flags & NETR_CFG_DISABLE_SECURE_RPC) == 0); netr_ssp_ctx.auth_verify_resp = ((flags & NETR_CFG_DISABLE_RESP_VERIF) == 0); netr_global_info.use_logon_ex = ((flags & NETR_CFG_DISABLE_SAMLOGONEX) == 0); } /* * AES-CFB8 has the odd property that 1/256 keys will encrypt * a full block of 0s to all 0s. In order to mitigate this, Windows DCs * now reject Challenges and Credentials where "none of the first 5 bytes * are unique" (i.e. [MS-NRPC] 3.1.4.1 "Session-Key Negotiation" Step 7). * This detects that condition so that we can avoid having our connection * rejected unexpectedly. * * I've interpreted this condition as 'amongst the first 5 bytes, * at least one must appear exactly once'. * * NOTE: Win2012r2 seems to only reject challenges whose first 5 bytes are 0. */ boolean_t passes_dc_mitigation(uint8_t *buf) { int i, j; for (i = 0; i < 5; i++) { for (j = 0; j < 5; j++) { if (i != j && buf[i] == buf[j]) break; } /* if this byte didn't match any other byte, this passes */ if (j == 5) return (B_TRUE); } /* None of the bytes were unique - the check fails */ return (B_FALSE); } /* * netlogon_auth * * This is the core of the NETLOGON authentication protocol. * Do the challenge response authentication. * * Prior to calling this function, an anonymous session to the NETLOGON * pipe on a domain controller(server) should have already been opened. * * Upon a successful NETLOGON credential chain establishment, the * netlogon sequence number will be set to match the kpasswd sequence * number. * */ DWORD netlogon_auth(char *server, char *domain, DWORD flags) { mlsvc_handle_t netr_handle; netr_info_t *netr_info; int rc; DWORD leout_rc[2]; boolean_t retry; DWORD status; /* * [MS-NRPC] 3.1.4.1 "Session-Key Negotiation" * Negotiation happens on an 'unprotected RPC channel' * (no RPC-level auth). */ status = netr_open(server, domain, &netr_handle); if (status != 0) { syslog(LOG_ERR, "netlogon_auth remote open failed (%s)", xlate_nt_status(status)); return (status); } netr_info = &netr_global_info; bzero(&netr_info->session_key, sizeof (netr_info->session_key)); netr_info->flags = flags; rc = smb_getnetbiosname(netr_info->hostname, NETBIOS_NAME_SZ); if (rc != 0) goto errout; /* server is our DC. Note: normally an FQDN. */ (void) snprintf(netr_info->server, sizeof (netr_info->server), "\\\\%s", server); /* * Domain (FQDN and NetBIOS) Name needed for Netlogon SSP-based * Secure RPC. */ rc = smb_getdomainname(netr_info->nb_domain, sizeof (netr_info->nb_domain)); if (rc != 0) goto errout; rc = smb_getfqdomainname(netr_info->fqdn_domain, sizeof (netr_info->fqdn_domain)); if (rc != 0) goto errout; /* * [MS-NRPC] 3.1.4.1 "Session-Key Negotiation" Step 7 * Windows DCs will reject negotiate attempts if none of the first * 5 bytes of the Challenge are unique. * Keep retrying until we've generated one that satisfies this. */ do { retry = B_FALSE; LE_OUT32(&leout_rc[0], arc4random()); LE_OUT32(&leout_rc[1], arc4random()); (void) memcpy(&netr_info->client_challenge, leout_rc, sizeof (struct netr_credential)); if (!passes_dc_mitigation(netr_info->client_challenge.data)) retry = B_TRUE; } while (retry); if ((rc = netr_server_req_challenge(&netr_handle, netr_info)) == 0) { rc = netr_server_authenticate2(&netr_handle, netr_info); if (rc == 0) { /* * TODO: (later) When joining a domain using a * pre-created machine account, should do: * netr_server_password_set(&netr_handle, netr_info); * Nexenta issue 11960 */ smb_update_netlogon_seqnum(); netr_info->flags |= NETR_FLG_VALID; } } errout: (void) netr_close(&netr_handle); return ((rc) ? NT_STATUS_UNSUCCESSFUL : NT_STATUS_SUCCESS); } /* * netr_open * * Open an anonymous session to the NETLOGON pipe on a domain controller * and bind to the NETR RPC interface. * * We store the remote server information, which is used to drive Windows * version specific behavior. * * Returns 0 or NT status */ DWORD netr_open(char *server, char *domain, mlsvc_handle_t *netr_handle) { char user[SMB_USERNAME_MAXLEN]; DWORD status; smb_ipc_get_user(user, SMB_USERNAME_MAXLEN); status = ndr_rpc_bind(netr_handle, server, domain, user, "NETR"); return (status); } uint32_t auth_context_id = 1; DWORD netr_open_secure(char *server, char *domain, mlsvc_handle_t *netr_handle) { char user[SMB_USERNAME_MAXLEN]; DWORD status; smb_ipc_get_user(user, SMB_USERNAME_MAXLEN); /* * If the server doesn't support SECURE_RPC_FLAG, or we've disabled * secure rpc (netr_global_info.use_secure_rpc), then SECURE_RPC_FLAG * won't be in the set of negotiated flags. Don't use SecureRPC if * that's the case. */ if ((netr_global_info.nego_flags & NETR_NEGO_SECURE_RPC_FLAG) != 0) { netr_ssp_ctx.auth_context_id = auth_context_id++; status = ndr_rpc_bind_secure(netr_handle, server, domain, user, "NETR", &netr_ssp_ctx); } else { status = ndr_rpc_bind(netr_handle, server, domain, user, "NETR"); } return (status); } /* * netr_close * * Close a NETLOGON pipe and free the RPC context. */ int netr_close(mlsvc_handle_t *netr_handle) { ndr_rpc_unbind(netr_handle); return (0); } /* * netr_server_req_challenge */ static int netr_server_req_challenge(mlsvc_handle_t *netr_handle, netr_info_t *netr_info) { struct netr_ServerReqChallenge arg; int opnum; bzero(&arg, sizeof (struct netr_ServerReqChallenge)); opnum = NETR_OPNUM_ServerReqChallenge; arg.servername = (unsigned char *)netr_info->server; arg.hostname = (unsigned char *)netr_info->hostname; (void) memcpy(&arg.client_challenge, &netr_info->client_challenge, sizeof (struct netr_credential)); if (ndr_rpc_call(netr_handle, opnum, &arg) != 0) return (-1); if (arg.status != 0) { ndr_rpc_status(netr_handle, opnum, arg.status); ndr_rpc_release(netr_handle); return (-1); } (void) memcpy(&netr_info->server_challenge, &arg.server_challenge, sizeof (struct netr_credential)); ndr_rpc_release(netr_handle); return (0); } uint32_t netr_server_auth2_flags = NETR_NEGO_BASE_FLAGS | NETR_NEGO_STRONGKEY_FLAG | NETR_NEGO_SECURE_RPC_FLAG; /* * netr_server_authenticate2 */ static int netr_server_authenticate2(mlsvc_handle_t *netr_handle, netr_info_t *netr_info) { struct netr_ServerAuthenticate2 arg; /* sizeof netr_info->hostname, + 1 for the '$' */ char account_name[(NETBIOS_NAME_SZ * 2) + 1]; int opnum; int rc; bzero(&arg, sizeof (struct netr_ServerAuthenticate2)); opnum = NETR_OPNUM_ServerAuthenticate2; (void) snprintf(account_name, sizeof (account_name), "%s$", netr_info->hostname); smb_tracef("server=[%s] account_name=[%s] hostname=[%s]\n", netr_info->server, account_name, netr_info->hostname); arg.servername = (unsigned char *)netr_info->server; arg.account_name = (unsigned char *)account_name; arg.account_type = NETR_WKSTA_TRUST_ACCOUNT_TYPE; arg.hostname = (unsigned char *)netr_info->hostname; arg.negotiate_flags = netr_server_auth2_flags; /* * If we've disabled SecureRPC, remove it from our negotiate_flags * so that the returned flags don't include it. We won't later use * SecureRPC if the returned flags don't include the flag. */ if (!netr_global_info.use_secure_rpc) arg.negotiate_flags &= ~NETR_NEGO_SECURE_RPC_FLAG; if (arg.negotiate_flags & NETR_NEGO_STRONGKEY_FLAG) { if (netr_gen_skey128(netr_info) != SMBAUTH_SUCCESS) return (-1); } else { if (netr_gen_skey64(netr_info) != SMBAUTH_SUCCESS) return (-1); } /* * We can't 'fiddle' with anything here to prevent getting bitten by * ClientStoredCredential-based mitigations. * * If we're using SamLogonEx, we won't use authenticators unless * some other NetLogon command is implemented and used. */ if (netr_gen_credentials(netr_info->session_key.key, &netr_info->client_challenge, 0, &netr_info->client_credential, B_FALSE) != SMBAUTH_SUCCESS) { return (-1); } if (netr_gen_credentials(netr_info->session_key.key, &netr_info->server_challenge, 0, &netr_info->server_credential, B_FALSE) != SMBAUTH_SUCCESS) { return (-1); } (void) memcpy(&arg.client_credential, &netr_info->client_credential, sizeof (struct netr_credential)); if (ndr_rpc_call(netr_handle, opnum, &arg) != 0) return (-1); if (arg.status != 0) { ndr_rpc_status(netr_handle, opnum, arg.status); ndr_rpc_release(netr_handle); return (-1); } /* The server returns the intersection of our flags and their flags. */ netr_info->nego_flags = arg.negotiate_flags; rc = memcmp(&netr_info->server_credential, &arg.server_credential, sizeof (struct netr_credential)); ndr_rpc_release(netr_handle); return (rc); } /* * netr_gen_skey128 * * Generate a 128-bit session key from the client and server challenges. * See "Session-Key Computation" section of MS-NRPC document. */ int netr_gen_skey128(netr_info_t *netr_info) { unsigned char ntlmhash[SMBAUTH_HASH_SZ]; int rc = SMBAUTH_FAILURE; CK_RV rv; CK_MECHANISM mechanism; CK_SESSION_HANDLE hSession; CK_ULONG diglen = MD_DIGEST_LEN; unsigned char md5digest[MD_DIGEST_LEN]; unsigned char zerobuf[NETR_SESSKEY_ZEROBUF_SZ]; bzero(ntlmhash, SMBAUTH_HASH_SZ); /* * We should check (netr_info->flags & NETR_FLG_INIT) and use * the appropriate password but it isn't working yet. So we * always use the default one for now. */ bzero(netr_info->password, sizeof (netr_info->password)); rc = smb_config_getstr(SMB_CI_MACHINE_PASSWD, (char *)netr_info->password, sizeof (netr_info->password)); if ((rc != SMBD_SMF_OK) || *netr_info->password == '\0') { return (SMBAUTH_FAILURE); } rc = smb_auth_ntlm_hash((char *)netr_info->password, ntlmhash); if (rc != SMBAUTH_SUCCESS) { explicit_bzero(&netr_info->password, sizeof (netr_info->password)); return (SMBAUTH_FAILURE); } bzero(zerobuf, NETR_SESSKEY_ZEROBUF_SZ); mechanism.mechanism = CKM_MD5; mechanism.pParameter = 0; mechanism.ulParameterLen = 0; rv = SUNW_C_GetMechSession(mechanism.mechanism, &hSession); if (rv != CKR_OK) { rc = SMBAUTH_FAILURE; goto errout; } rv = C_DigestInit(hSession, &mechanism); if (rv != CKR_OK) goto cleanup; rv = C_DigestUpdate(hSession, (CK_BYTE_PTR)zerobuf, NETR_SESSKEY_ZEROBUF_SZ); if (rv != CKR_OK) goto cleanup; rv = C_DigestUpdate(hSession, (CK_BYTE_PTR)netr_info->client_challenge.data, NETR_CRED_DATA_SZ); if (rv != CKR_OK) goto cleanup; rv = C_DigestUpdate(hSession, (CK_BYTE_PTR)netr_info->server_challenge.data, NETR_CRED_DATA_SZ); if (rv != CKR_OK) goto cleanup; rv = C_DigestFinal(hSession, (CK_BYTE_PTR)md5digest, &diglen); if (rv != CKR_OK) goto cleanup; rc = smb_auth_hmac_md5(md5digest, diglen, ntlmhash, SMBAUTH_HASH_SZ, netr_info->session_key.key); netr_info->session_key.len = NETR_SESSKEY128_SZ; cleanup: (void) C_CloseSession(hSession); errout: explicit_bzero(&netr_info->password, sizeof (netr_info->password)); explicit_bzero(ntlmhash, sizeof (ntlmhash)); return (rc); } /* * netr_gen_skey64 * * Generate a 64-bit session key from the client and server challenges. * See "Session-Key Computation" section of MS-NRPC document. * * The algorithm is a two stage hash. For the first hash, the input is * the combination of the client and server challenges, the key is * the first 7 bytes of the password. The initial password is formed * using the NT password hash on the local hostname in lower case. * The result is stored in a temporary buffer. * * input: challenge * key: passwd lower 7 bytes * output: intermediate result * * For the second hash, the input is the result of the first hash and * the key is the last 7 bytes of the password. * * input: result of first hash * key: passwd upper 7 bytes * output: session_key * * The final output should be the session key. * * FYI: smb_auth_DES(output, key, input) * * If any difficulties occur using the cryptographic framework, the * function returns SMBAUTH_FAILURE. Otherwise SMBAUTH_SUCCESS is * returned. */ int netr_gen_skey64(netr_info_t *netr_info) { unsigned char md4hash[32]; unsigned char buffer[8]; DWORD data[2]; DWORD *client_challenge; DWORD *server_challenge; int rc; DWORD le_data[2]; client_challenge = (DWORD *)(uintptr_t)&netr_info->client_challenge; server_challenge = (DWORD *)(uintptr_t)&netr_info->server_challenge; bzero(md4hash, 32); /* * We should check (netr_info->flags & NETR_FLG_INIT) and use * the appropriate password but it isn't working yet. So we * always use the default one for now. */ bzero(netr_info->password, sizeof (netr_info->password)); rc = smb_config_getstr(SMB_CI_MACHINE_PASSWD, (char *)netr_info->password, sizeof (netr_info->password)); if ((rc != SMBD_SMF_OK) || *netr_info->password == '\0') { return (SMBAUTH_FAILURE); } rc = smb_auth_ntlm_hash((char *)netr_info->password, md4hash); if (rc != SMBAUTH_SUCCESS) { rc = SMBAUTH_FAILURE; goto out; } data[0] = LE_IN32(&client_challenge[0]) + LE_IN32(&server_challenge[0]); data[1] = LE_IN32(&client_challenge[1]) + LE_IN32(&server_challenge[1]); LE_OUT32(&le_data[0], data[0]); LE_OUT32(&le_data[1], data[1]); rc = smb_auth_DES(buffer, 8, md4hash, NETR_DESKEY_LEN, (unsigned char *)le_data, 8); if (rc != SMBAUTH_SUCCESS) goto out; netr_info->session_key.len = NETR_SESSKEY64_SZ; rc = smb_auth_DES(netr_info->session_key.key, netr_info->session_key.len, &md4hash[9], NETR_DESKEY_LEN, buffer, 8); out: explicit_bzero(&netr_info->password, sizeof (netr_info->password)); explicit_bzero(md4hash, sizeof (md4hash)); explicit_bzero(buffer, sizeof (buffer)); return (rc); } /* * netr_gen_credentials * * Generate a set of credentials from a challenge and a session key. * The algorithm is a two stage hash. For the first hash, the * timestamp is added to the challenge and the result is stored in a * temporary buffer: * * input: challenge (including timestamp) * key: session_key * output: intermediate result * * For the second hash, the input is the result of the first hash and * a strange partial key is used: * * input: result of first hash * key: funny partial key * output: credentiails * * The final output should be an encrypted set of credentials. * * FYI: smb_auth_DES(output, key, input) * * If any difficulties occur using the cryptographic framework, the * function returns SMBAUTH_FAILURE. Otherwise SMBAUTH_SUCCESS is * returned. */ int netr_gen_credentials(BYTE *session_key, netr_cred_t *challenge, DWORD timestamp, netr_cred_t *out_cred, boolean_t retry) { unsigned char buffer[8]; DWORD data[2]; DWORD le_data[2]; DWORD *p; int rc; p = (DWORD *)(uintptr_t)challenge; data[0] = LE_IN32(&p[0]) + timestamp; data[1] = LE_IN32(&p[1]); LE_OUT32(&le_data[0], data[0]); LE_OUT32(&le_data[1], data[1]); if (smb_auth_DES(buffer, 8, session_key, NETR_DESKEY_LEN, (unsigned char *)le_data, 8) != SMBAUTH_SUCCESS) return (SMBAUTH_FAILURE); rc = smb_auth_DES(out_cred->data, 8, &session_key[NETR_DESKEY_LEN], NETR_DESKEY_LEN, buffer, 8); /* * [MS-NRPC] 3.1.4.6 "Calling Methods Requiring Session-Key * Establishment" Step 6 * * Windows DCs will reject authenticators if none of the first * 5 bytes of the ClientStoredCredential are unique. * Keep retrying until we've generated one that satisfies this, * but only if the caller can handle retries. */ if (retry && !passes_dc_mitigation(out_cred->data)) return (SMBAUTH_RETRY); return (rc); } /* * netr_server_password_set * * Attempt to change the trust account password for this system. * * Note that this call may legitimately fail if the registry on the * domain controller has been setup to deny attempts to change the * trust account password. In this case we should just continue to * use the original password. * * Possible status values: * NT_STATUS_ACCESS_DENIED */ int netr_server_password_set(mlsvc_handle_t *netr_handle, netr_info_t *netr_info) { struct netr_PasswordSet arg; int opnum; BYTE new_password[NETR_OWF_PASSWORD_SZ]; char account_name[NETBIOS_NAME_SZ * 2]; bzero(&arg, sizeof (struct netr_PasswordSet)); opnum = NETR_OPNUM_ServerPasswordSet; (void) snprintf(account_name, sizeof (account_name), "%s$", netr_info->hostname); arg.servername = (unsigned char *)netr_info->server; arg.account_name = (unsigned char *)account_name; arg.sec_chan_type = NETR_WKSTA_TRUST_ACCOUNT_TYPE; arg.hostname = (unsigned char *)netr_info->hostname; /* * Set up the client side authenticator. */ if (netr_setup_authenticator(netr_info, &arg.auth, 0) != SMBAUTH_SUCCESS) { return (-1); } /* * Generate a new password from the old password. */ if (netr_gen_password(netr_info->session_key.key, netr_info->password, new_password) == SMBAUTH_FAILURE) { return (-1); } (void) memcpy(&arg.owf_password, &new_password, NETR_OWF_PASSWORD_SZ); if (ndr_rpc_call(netr_handle, opnum, &arg) != 0) return (-1); if (arg.status != 0) { ndr_rpc_status(netr_handle, opnum, arg.status); ndr_rpc_release(netr_handle); return (-1); } /* * Check the returned credentials. The server returns the new * client credential rather than the new server credentiali, * as documented elsewhere. * * Generate the new seed for the credential chain. Increment * the timestamp and add it to the client challenge. Then we * need to copy the challenge to the credential field in * preparation for the next cycle. */ if (netr_validate_chain(netr_info, &arg.auth) == 0) { /* * Save the new password. */ (void) memcpy(netr_info->password, new_password, NETR_OWF_PASSWORD_SZ); } ndr_rpc_release(netr_handle); return (0); } /* * netr_gen_password * * Generate a new pasword from the old password and the session key. * The algorithm is a two stage hash. The session key is used in the * first hash but only part of the session key is used in the second * hash. * * If any difficulties occur using the cryptographic framework, the * function returns SMBAUTH_FAILURE. Otherwise SMBAUTH_SUCCESS is * returned. */ static int netr_gen_password(BYTE *session_key, BYTE *old_password, BYTE *new_password) { int rv; rv = smb_auth_DES(new_password, 8, session_key, NETR_DESKEY_LEN, old_password, 8); if (rv != SMBAUTH_SUCCESS) return (rv); rv = smb_auth_DES(&new_password[8], 8, &session_key[NETR_DESKEY_LEN], NETR_DESKEY_LEN, &old_password[8], 8); return (rv); } /* * Todo: need netr_server_password_set2() * used by "unsecure join". (NX 11960) */