/** * FreeRDP: A Remote Desktop Protocol Implementation * Network Level Authentication (NLA) * * Copyright 2010-2012 Marc-Andre Moreau * Copyright 2015 Thincast Technologies GmbH * Copyright 2015 DI (FH) Martin Haimberger * Copyright 2016 Martin Fleisz * Copyright 2017 Dorian Ducournau * Copyright 2022 David Fort * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "../crypto/tls.h" #include "nla.h" #include "utils.h" #include "credssp_auth.h" #include #include "settings.h" #define TAG FREERDP_TAG("core.nla") #define SERVER_KEY "Software\\" FREERDP_VENDOR_STRING "\\" FREERDP_PRODUCT_STRING "\\Server" #define NLA_AUTH_PKG NEGO_SSP_NAME /** * TSRequest ::= SEQUENCE { * version [0] INTEGER, * negoTokens [1] NegoData OPTIONAL, * authInfo [2] OCTET STRING OPTIONAL, * pubKeyAuth [3] OCTET STRING OPTIONAL, * errorCode [4] INTEGER OPTIONAL * } * * NegoData ::= SEQUENCE OF NegoDataItem * * NegoDataItem ::= SEQUENCE { * negoToken [0] OCTET STRING * } * * TSCredentials ::= SEQUENCE { * credType [0] INTEGER, * credentials [1] OCTET STRING * } * * TSPasswordCreds ::= SEQUENCE { * domainName [0] OCTET STRING, * userName [1] OCTET STRING, * password [2] OCTET STRING * } * * TSSmartCardCreds ::= SEQUENCE { * pin [0] OCTET STRING, * cspData [1] TSCspDataDetail, * userHint [2] OCTET STRING OPTIONAL, * domainHint [3] OCTET STRING OPTIONAL * } * * TSCspDataDetail ::= SEQUENCE { * keySpec [0] INTEGER, * cardName [1] OCTET STRING OPTIONAL, * readerName [2] OCTET STRING OPTIONAL, * containerName [3] OCTET STRING OPTIONAL, * cspName [4] OCTET STRING OPTIONAL * } * */ #define NLA_PKG_NAME CREDSSP_AUTH_PKG_SPNEGO struct rdp_nla { BOOL server; NLA_STATE state; ULONG sendSeqNum; ULONG recvSeqNum; rdpContext* rdpcontext; rdpTransport* transport; UINT32 version; UINT32 peerVersion; UINT32 errorCode; /* Lifetime of buffer nla_new -> nla_free */ SecBuffer ClientNonce; /* Depending on protocol version a random nonce or a value read from the server. */ SecBuffer negoToken; SecBuffer pubKeyAuth; SecBuffer authInfo; SecBuffer PublicKey; SecBuffer tsCredentials; SEC_WINNT_AUTH_IDENTITY* identity; rdpCredsspAuth* auth; char* pkinitArgs; SmartcardCertInfo* smartcardCert; BYTE certSha1[20]; }; static BOOL nla_send(rdpNla* nla); static int nla_server_recv(rdpNla* nla); static BOOL nla_encrypt_public_key_echo(rdpNla* nla); static BOOL nla_encrypt_public_key_hash(rdpNla* nla); static BOOL nla_decrypt_public_key_echo(rdpNla* nla); static BOOL nla_decrypt_public_key_hash(rdpNla* nla); static BOOL nla_encrypt_ts_credentials(rdpNla* nla); static BOOL nla_decrypt_ts_credentials(rdpNla* nla); static void nla_buffer_free(rdpNla* nla) { WINPR_ASSERT(nla); sspi_SecBufferFree(&nla->pubKeyAuth); sspi_SecBufferFree(&nla->authInfo); sspi_SecBufferFree(&nla->negoToken); sspi_SecBufferFree(&nla->ClientNonce); sspi_SecBufferFree(&nla->PublicKey); } static BOOL nla_Digest_Update_From_SecBuffer(WINPR_DIGEST_CTX* ctx, const SecBuffer* buffer) { if (!buffer) return FALSE; return winpr_Digest_Update(ctx, buffer->pvBuffer, buffer->cbBuffer); } static BOOL nla_sec_buffer_alloc(SecBuffer* buffer, size_t size) { WINPR_ASSERT(buffer); sspi_SecBufferFree(buffer); if (size > ULONG_MAX) return FALSE; if (!sspi_SecBufferAlloc(buffer, (ULONG)size)) return FALSE; WINPR_ASSERT(buffer); buffer->BufferType = SECBUFFER_TOKEN; return TRUE; } static BOOL nla_sec_buffer_alloc_from_data(SecBuffer* buffer, const BYTE* data, size_t offset, size_t size) { if (!nla_sec_buffer_alloc(buffer, offset + size)) return FALSE; WINPR_ASSERT(buffer); BYTE* pb = buffer->pvBuffer; memcpy(&pb[offset], data, size); return TRUE; } /* CredSSP Client-To-Server Binding Hash\0 */ static const BYTE ClientServerHashMagic[] = { 0x43, 0x72, 0x65, 0x64, 0x53, 0x53, 0x50, 0x20, 0x43, 0x6C, 0x69, 0x65, 0x6E, 0x74, 0x2D, 0x54, 0x6F, 0x2D, 0x53, 0x65, 0x72, 0x76, 0x65, 0x72, 0x20, 0x42, 0x69, 0x6E, 0x64, 0x69, 0x6E, 0x67, 0x20, 0x48, 0x61, 0x73, 0x68, 0x00 }; /* CredSSP Server-To-Client Binding Hash\0 */ static const BYTE ServerClientHashMagic[] = { 0x43, 0x72, 0x65, 0x64, 0x53, 0x53, 0x50, 0x20, 0x53, 0x65, 0x72, 0x76, 0x65, 0x72, 0x2D, 0x54, 0x6F, 0x2D, 0x43, 0x6C, 0x69, 0x65, 0x6E, 0x74, 0x20, 0x42, 0x69, 0x6E, 0x64, 0x69, 0x6E, 0x67, 0x20, 0x48, 0x61, 0x73, 0x68, 0x00 }; static const UINT32 NonceLength = 32; static BOOL nla_adjust_settings_from_smartcard(rdpNla* nla) { BOOL ret = FALSE; WINPR_ASSERT(nla); WINPR_ASSERT(nla->rdpcontext); rdpSettings* settings = nla->rdpcontext->settings; WINPR_ASSERT(settings); if (!settings->SmartcardLogon) return TRUE; smartcardCertInfo_Free(nla->smartcardCert); if (!smartcard_getCert(nla->rdpcontext, &nla->smartcardCert, FALSE)) { WLog_ERR(TAG, "unable to get smartcard certificate for logon"); return FALSE; } if (!settings->CspName) { if (nla->smartcardCert->csp && !freerdp_settings_set_string_from_utf16( settings, FreeRDP_CspName, nla->smartcardCert->csp)) { WLog_ERR(TAG, "unable to set CSP name"); goto out; } if (!settings->CspName && !freerdp_settings_set_string(settings, FreeRDP_CspName, MS_SCARD_PROV_A)) { WLog_ERR(TAG, "unable to set CSP name"); goto out; } } if (!settings->ReaderName && nla->smartcardCert->reader) { if (!freerdp_settings_set_string_from_utf16(settings, FreeRDP_ReaderName, nla->smartcardCert->reader)) { WLog_ERR(TAG, "unable to copy reader name"); goto out; } } if (!settings->ContainerName && nla->smartcardCert->containerName) { if (!freerdp_settings_set_string_from_utf16(settings, FreeRDP_ContainerName, nla->smartcardCert->containerName)) { WLog_ERR(TAG, "unable to copy container name"); goto out; } } memcpy(nla->certSha1, nla->smartcardCert->sha1Hash, sizeof(nla->certSha1)); if (nla->smartcardCert->pkinitArgs) { nla->pkinitArgs = _strdup(nla->smartcardCert->pkinitArgs); if (!nla->pkinitArgs) { WLog_ERR(TAG, "unable to copy pkinitArgs"); goto out; } } ret = TRUE; out: return ret; } static BOOL nla_client_setup_identity(rdpNla* nla) { BOOL PromptPassword = FALSE; WINPR_ASSERT(nla); WINPR_ASSERT(nla->rdpcontext); rdpSettings* settings = nla->rdpcontext->settings; WINPR_ASSERT(settings); freerdp* instance = nla->rdpcontext->instance; WINPR_ASSERT(instance); /* */ if ((utils_str_is_empty(settings->Username) || (utils_str_is_empty(settings->Password) && utils_str_is_empty((const char*)settings->RedirectionPassword)))) { PromptPassword = TRUE; } if (PromptPassword && !utils_str_is_empty(settings->Username)) { WINPR_SAM* sam = SamOpen(NULL, TRUE); if (sam) { const size_t userLength = strlen(settings->Username); WINPR_SAM_ENTRY* entry = SamLookupUserA( sam, settings->Username, userLength + 1 /* ensure '\0' is checked too */, NULL, 0); if (entry) { /** * The user could be found in SAM database. * Use entry in SAM database later instead of prompt */ PromptPassword = FALSE; SamFreeEntry(sam, entry); } SamClose(sam); } } #ifndef _WIN32 if (PromptPassword) { if (settings->RestrictedAdminModeRequired) { if ((settings->PasswordHash) && (strlen(settings->PasswordHash) > 0)) PromptPassword = FALSE; } } #endif BOOL smartCardLogonWasDisabled = !settings->SmartcardLogon; if (PromptPassword) { switch (utils_authenticate(instance, AUTH_NLA, TRUE)) { case AUTH_SKIP: case AUTH_SUCCESS: break; case AUTH_CANCELLED: freerdp_set_last_error_log(instance->context, FREERDP_ERROR_CONNECT_CANCELLED); return FALSE; case AUTH_NO_CREDENTIALS: WLog_INFO(TAG, "No credentials provided - using NULL identity"); break; default: return FALSE; } } if (!settings->Username) { sspi_FreeAuthIdentity(nla->identity); nla->identity = NULL; } else if (settings->SmartcardLogon) { if (smartCardLogonWasDisabled) { if (!nla_adjust_settings_from_smartcard(nla)) return FALSE; } if (!identity_set_from_smartcard_hash(nla->identity, settings, FreeRDP_Username, FreeRDP_Domain, FreeRDP_Password, nla->certSha1, sizeof(nla->certSha1))) return FALSE; } else { BOOL usePassword = TRUE; if (settings->RedirectionPassword && (settings->RedirectionPasswordLength > 0)) { if (!identity_set_from_settings_with_pwd( nla->identity, settings, FreeRDP_Username, FreeRDP_Domain, (const WCHAR*)settings->RedirectionPassword, settings->RedirectionPasswordLength / sizeof(WCHAR))) return FALSE; usePassword = FALSE; } if (settings->RestrictedAdminModeRequired) { if (settings->PasswordHash && strlen(settings->PasswordHash) == 32) { if (!identity_set_from_settings(nla->identity, settings, FreeRDP_Username, FreeRDP_Domain, FreeRDP_PasswordHash)) return FALSE; /** * Increase password hash length by LB_PASSWORD_MAX_LENGTH to obtain a * length exceeding the maximum (LB_PASSWORD_MAX_LENGTH) and use it this for * hash identification in WinPR. */ nla->identity->PasswordLength += LB_PASSWORD_MAX_LENGTH; usePassword = FALSE; } } if (usePassword) { if (!identity_set_from_settings(nla->identity, settings, FreeRDP_Username, FreeRDP_Domain, FreeRDP_Password)) return FALSE; } } return TRUE; } static int nla_client_init(rdpNla* nla) { WINPR_ASSERT(nla); WINPR_ASSERT(nla->rdpcontext); rdpSettings* settings = nla->rdpcontext->settings; WINPR_ASSERT(settings); nla_set_state(nla, NLA_STATE_INITIAL); if (!nla_adjust_settings_from_smartcard(nla)) return -1; if (!credssp_auth_init(nla->auth, NLA_AUTH_PKG, NULL)) return -1; if (!nla_client_setup_identity(nla)) return -1; const char* hostname = freerdp_settings_get_server_name(settings); if (!credssp_auth_setup_client(nla->auth, "TERMSRV", hostname, nla->identity, nla->pkinitArgs)) return -1; rdpTls* tls = transport_get_tls(nla->transport); if (!tls) { WLog_ERR(TAG, "Unknown NLA transport layer"); return -1; } if (!nla_sec_buffer_alloc_from_data(&nla->PublicKey, tls->PublicKey, 0, tls->PublicKeyLength)) { WLog_ERR(TAG, "Failed to allocate sspi secBuffer"); return -1; } return 1; } int nla_client_begin(rdpNla* nla) { WINPR_ASSERT(nla); if (nla_client_init(nla) < 1) return -1; if (nla_get_state(nla) != NLA_STATE_INITIAL) return -1; /* * from tspkg.dll: 0x00000132 * ISC_REQ_MUTUAL_AUTH * ISC_REQ_CONFIDENTIALITY * ISC_REQ_USE_SESSION_KEY * ISC_REQ_ALLOCATE_MEMORY */ credssp_auth_set_flags(nla->auth, ISC_REQ_MUTUAL_AUTH | ISC_REQ_CONFIDENTIALITY); const int rc = credssp_auth_authenticate(nla->auth); switch (rc) { case 0: if (!nla_send(nla)) return -1; nla_set_state(nla, NLA_STATE_NEGO_TOKEN); break; case 1: if (credssp_auth_have_output_token(nla->auth)) { if (!nla_send(nla)) return -1; } nla_set_state(nla, NLA_STATE_FINAL); break; default: return -1; } return 1; } static int nla_client_recv_nego_token(rdpNla* nla) { credssp_auth_take_input_buffer(nla->auth, &nla->negoToken); const int rc = credssp_auth_authenticate(nla->auth); switch (rc) { case 0: if (!nla_send(nla)) return -1; break; case 1: /* completed */ { int res = -1; if (nla->peerVersion < 5) res = nla_encrypt_public_key_echo(nla); else res = nla_encrypt_public_key_hash(nla); if (!res) return -1; if (!nla_send(nla)) return -1; nla_set_state(nla, NLA_STATE_PUB_KEY_AUTH); } break; default: return -1; } return 1; } static int nla_client_recv_pub_key_auth(rdpNla* nla) { BOOL rc = FALSE; WINPR_ASSERT(nla); /* Verify Server Public Key Echo */ if (nla->peerVersion < 5) rc = nla_decrypt_public_key_echo(nla); else rc = nla_decrypt_public_key_hash(nla); sspi_SecBufferFree(&nla->pubKeyAuth); if (!rc) return -1; /* Send encrypted credentials */ rc = nla_encrypt_ts_credentials(nla); if (!rc) return -1; if (!nla_send(nla)) return -1; nla_set_state(nla, NLA_STATE_AUTH_INFO); return 1; } static int nla_client_recv(rdpNla* nla) { WINPR_ASSERT(nla); switch (nla_get_state(nla)) { case NLA_STATE_NEGO_TOKEN: return nla_client_recv_nego_token(nla); case NLA_STATE_PUB_KEY_AUTH: return nla_client_recv_pub_key_auth(nla); case NLA_STATE_FINAL: default: WLog_ERR(TAG, "NLA in invalid client receive state %s", nla_get_state_str(nla_get_state(nla))); return -1; } } static int nla_client_authenticate(rdpNla* nla) { int rc = -1; WINPR_ASSERT(nla); wStream* s = Stream_New(NULL, 4096); if (!s) { WLog_ERR(TAG, "Stream_New failed!"); return -1; } if (nla_client_begin(nla) < 1) goto fail; while (nla_get_state(nla) < NLA_STATE_AUTH_INFO) { Stream_SetPosition(s, 0); const int status = transport_read_pdu(nla->transport, s); if (status < 0) { WLog_ERR(TAG, "nla_client_authenticate failure"); goto fail; } const int status2 = nla_recv_pdu(nla, s); if (status2 < 0) goto fail; } rc = 1; fail: Stream_Free(s, TRUE); return rc; } /** * Initialize NTLMSSP authentication module (server). */ static int nla_server_init(rdpNla* nla) { WINPR_ASSERT(nla); rdpTls* tls = transport_get_tls(nla->transport); WINPR_ASSERT(tls); if (!nla_sec_buffer_alloc_from_data(&nla->PublicKey, tls->PublicKey, 0, tls->PublicKeyLength)) { WLog_ERR(TAG, "Failed to allocate SecBuffer for public key"); return -1; } if (!credssp_auth_init(nla->auth, NLA_AUTH_PKG, NULL)) return -1; if (!credssp_auth_setup_server(nla->auth)) return -1; nla_set_state(nla, NLA_STATE_INITIAL); return 1; } static wStream* nla_server_recv_stream(rdpNla* nla) { wStream* s = NULL; int status = -1; WINPR_ASSERT(nla); s = Stream_New(NULL, 4096); if (!s) goto fail; status = transport_read_pdu(nla->transport, s); fail: if (status < 0) { WLog_ERR(TAG, "nla_recv() error: %d", status); Stream_Free(s, TRUE); return NULL; } return s; } static BOOL nla_server_recv_credentials(rdpNla* nla) { WINPR_ASSERT(nla); if (nla_server_recv(nla) < 0) return FALSE; if (!nla_decrypt_ts_credentials(nla)) return FALSE; if (!nla_impersonate(nla)) return FALSE; if (!nla_revert_to_self(nla)) return FALSE; return TRUE; } /** * Authenticate with client using CredSSP (server). * @param nla The NLA instance to use * * @return 1 if authentication is successful */ static int nla_server_authenticate(rdpNla* nla) { int ret = -1; WINPR_ASSERT(nla); if (nla_server_init(nla) < 1) goto fail; /* * from tspkg.dll: 0x00000112 * ASC_REQ_MUTUAL_AUTH * ASC_REQ_CONFIDENTIALITY * ASC_REQ_ALLOCATE_MEMORY */ credssp_auth_set_flags(nla->auth, ASC_REQ_MUTUAL_AUTH | ASC_REQ_CONFIDENTIALITY | ASC_REQ_CONNECTION | ASC_REQ_USE_SESSION_KEY | ASC_REQ_SEQUENCE_DETECT | ASC_REQ_EXTENDED_ERROR); /* Client is starting, here es the state machine: * * -- NLA_STATE_INITIAL --> NLA_STATE_INITIAL * ----->> sending... * ----->> protocol version 6 * ----->> nego token * ----->> client nonce * <<----- receiving... * <<----- protocol version 6 * <<----- nego token * ----->> sending... * ----->> protocol version 6 * ----->> nego token * ----->> public key auth * ----->> client nonce * -- NLA_STATE_NEGO_TOKEN --> NLA_STATE_PUB_KEY_AUTH * <<----- receiving... * <<----- protocol version 6 * <<----- public key info * ----->> sending... * ----->> protocol version 6 * ----->> auth info * ----->> client nonce * -- NLA_STATE_PUB_KEY_AUTH --> NLA_STATE */ while (TRUE) { int res = -1; if (nla_server_recv(nla) < 0) goto fail; WLog_DBG(TAG, "Receiving Authentication Token"); credssp_auth_take_input_buffer(nla->auth, &nla->negoToken); res = credssp_auth_authenticate(nla->auth); if (res == -1) { /* Special handling of these specific error codes as NTSTATUS_FROM_WIN32 unfortunately does not map directly to the corresponding NTSTATUS values */ switch (GetLastError()) { case ERROR_PASSWORD_MUST_CHANGE: nla->errorCode = STATUS_PASSWORD_MUST_CHANGE; break; case ERROR_PASSWORD_EXPIRED: nla->errorCode = STATUS_PASSWORD_EXPIRED; break; case ERROR_ACCOUNT_DISABLED: nla->errorCode = STATUS_ACCOUNT_DISABLED; break; default: nla->errorCode = NTSTATUS_FROM_WIN32(GetLastError()); break; } nla_send(nla); /* Access Denied */ goto fail; } if (res == 1) { /* Process final part of the nego token exchange */ if (credssp_auth_have_output_token(nla->auth)) { if (!nla_send(nla)) goto fail; if (nla_server_recv(nla) < 0) goto fail; WLog_DBG(TAG, "Receiving pubkey Token"); } if (nla->peerVersion < 5) res = nla_decrypt_public_key_echo(nla); else res = nla_decrypt_public_key_hash(nla); if (!res) goto fail; /* Clear nego token buffer or we will send it again to the client */ sspi_SecBufferFree(&nla->negoToken); if (nla->peerVersion < 5) res = nla_encrypt_public_key_echo(nla); else res = nla_encrypt_public_key_hash(nla); if (!res) goto fail; } /* send authentication token */ WLog_DBG(TAG, "Sending Authentication Token"); if (!nla_send(nla)) goto fail; if (res == 1) { ret = 1; break; } } /* Receive encrypted credentials */ if (!nla_server_recv_credentials(nla)) ret = -1; fail: nla_buffer_free(nla); return ret; } /** * Authenticate using CredSSP. * @param nla The NLA instance to use * * @return 1 if authentication is successful */ int nla_authenticate(rdpNla* nla) { WINPR_ASSERT(nla); if (nla->server) return nla_server_authenticate(nla); else return nla_client_authenticate(nla); } static void ap_integer_increment_le(BYTE* number, size_t size) { WINPR_ASSERT(number || (size == 0)); for (size_t index = 0; index < size; index++) { if (number[index] < 0xFF) { number[index]++; break; } else { number[index] = 0; continue; } } } static void ap_integer_decrement_le(BYTE* number, size_t size) { WINPR_ASSERT(number || (size == 0)); for (size_t index = 0; index < size; index++) { if (number[index] > 0) { number[index]--; break; } else { number[index] = 0xFF; continue; } } } BOOL nla_encrypt_public_key_echo(rdpNla* nla) { BOOL status = FALSE; WINPR_ASSERT(nla); sspi_SecBufferFree(&nla->pubKeyAuth); if (nla->server) { SecBuffer buf = { 0 }; if (!sspi_SecBufferAlloc(&buf, nla->PublicKey.cbBuffer)) return FALSE; ap_integer_increment_le(buf.pvBuffer, buf.cbBuffer); status = credssp_auth_encrypt(nla->auth, &buf, &nla->pubKeyAuth, NULL, nla->sendSeqNum++); sspi_SecBufferFree(&buf); } else { status = credssp_auth_encrypt(nla->auth, &nla->PublicKey, &nla->pubKeyAuth, NULL, nla->sendSeqNum++); } return status; } BOOL nla_encrypt_public_key_hash(rdpNla* nla) { BOOL status = FALSE; WINPR_DIGEST_CTX* sha256 = NULL; SecBuffer buf = { 0 }; WINPR_ASSERT(nla); const BYTE* hashMagic = nla->server ? ServerClientHashMagic : ClientServerHashMagic; const size_t hashSize = nla->server ? sizeof(ServerClientHashMagic) : sizeof(ClientServerHashMagic); if (!sspi_SecBufferAlloc(&buf, WINPR_SHA256_DIGEST_LENGTH)) return FALSE; /* generate SHA256 of following data: ClientServerHashMagic, Nonce, SubjectPublicKey */ if (!(sha256 = winpr_Digest_New())) goto out; if (!winpr_Digest_Init(sha256, WINPR_MD_SHA256)) goto out; /* include trailing \0 from hashMagic */ if (!winpr_Digest_Update(sha256, hashMagic, hashSize)) goto out; if (!nla_Digest_Update_From_SecBuffer(sha256, &nla->ClientNonce)) goto out; /* SubjectPublicKey */ if (!nla_Digest_Update_From_SecBuffer(sha256, &nla->PublicKey)) goto out; if (!winpr_Digest_Final(sha256, buf.pvBuffer, WINPR_SHA256_DIGEST_LENGTH)) goto out; sspi_SecBufferFree(&nla->pubKeyAuth); if (!credssp_auth_encrypt(nla->auth, &buf, &nla->pubKeyAuth, NULL, nla->sendSeqNum++)) goto out; status = TRUE; out: winpr_Digest_Free(sha256); sspi_SecBufferFree(&buf); return status; } BOOL nla_decrypt_public_key_echo(rdpNla* nla) { BOOL status = FALSE; SecBuffer public_key = { 0 }; if (!nla) goto fail; if (!credssp_auth_decrypt(nla->auth, &nla->pubKeyAuth, &public_key, nla->recvSeqNum++)) return FALSE; if (!nla->server) { /* server echos the public key +1 */ ap_integer_decrement_le(public_key.pvBuffer, public_key.cbBuffer); } if (public_key.cbBuffer != nla->PublicKey.cbBuffer || memcmp(public_key.pvBuffer, nla->PublicKey.pvBuffer, public_key.cbBuffer) != 0) { WLog_ERR(TAG, "Could not verify server's public key echo"); #if defined(WITH_DEBUG_NLA) WLog_ERR(TAG, "Expected (length = %" PRIu32 "):", nla->PublicKey.cbBuffer); winpr_HexDump(TAG, WLOG_ERROR, nla->PublicKey.pvBuffer, nla->PublicKey.cbBuffer); WLog_ERR(TAG, "Actual (length = %" PRIu32 "):", public_key.cbBuffer); winpr_HexDump(TAG, WLOG_ERROR, public_key.pvBuffer, public_key.cbBuffer); #endif /* DO NOT SEND CREDENTIALS! */ goto fail; } status = TRUE; fail: sspi_SecBufferFree(&public_key); return status; } BOOL nla_decrypt_public_key_hash(rdpNla* nla) { WINPR_DIGEST_CTX* sha256 = NULL; BYTE serverClientHash[WINPR_SHA256_DIGEST_LENGTH] = { 0 }; BOOL status = FALSE; WINPR_ASSERT(nla); const BYTE* hashMagic = nla->server ? ClientServerHashMagic : ServerClientHashMagic; const size_t hashSize = nla->server ? sizeof(ClientServerHashMagic) : sizeof(ServerClientHashMagic); SecBuffer hash = { 0 }; if (!credssp_auth_decrypt(nla->auth, &nla->pubKeyAuth, &hash, nla->recvSeqNum++)) return FALSE; /* generate SHA256 of following data: ServerClientHashMagic, Nonce, SubjectPublicKey */ if (!(sha256 = winpr_Digest_New())) goto fail; if (!winpr_Digest_Init(sha256, WINPR_MD_SHA256)) goto fail; /* include trailing \0 from hashMagic */ if (!winpr_Digest_Update(sha256, hashMagic, hashSize)) goto fail; if (!nla_Digest_Update_From_SecBuffer(sha256, &nla->ClientNonce)) goto fail; /* SubjectPublicKey */ if (!nla_Digest_Update_From_SecBuffer(sha256, &nla->PublicKey)) goto fail; if (!winpr_Digest_Final(sha256, serverClientHash, sizeof(serverClientHash))) goto fail; /* verify hash */ if (hash.cbBuffer != WINPR_SHA256_DIGEST_LENGTH || memcmp(serverClientHash, hash.pvBuffer, WINPR_SHA256_DIGEST_LENGTH) != 0) { WLog_ERR(TAG, "Could not verify server's hash"); /* DO NOT SEND CREDENTIALS! */ goto fail; } status = TRUE; fail: winpr_Digest_Free(sha256); sspi_SecBufferFree(&hash); return status; } static BOOL nla_read_ts_credentials(rdpNla* nla, SecBuffer* data) { WinPrAsn1Decoder dec = { 0 }; WinPrAsn1Decoder dec2 = { 0 }; WinPrAsn1_OctetString credentials = { 0 }; BOOL error = FALSE; WinPrAsn1_INTEGER credType = -1; WINPR_ASSERT(nla); WINPR_ASSERT(data); WinPrAsn1Decoder_InitMem(&dec, WINPR_ASN1_DER, (BYTE*)data->pvBuffer, data->cbBuffer); /* TSCredentials */ if (!WinPrAsn1DecReadSequence(&dec, &dec2)) return FALSE; dec = dec2; /* credType [0] INTEGER */ if (!WinPrAsn1DecReadContextualInteger(&dec, 0, &error, &credType)) return FALSE; /* credentials [1] OCTET STRING */ if (!WinPrAsn1DecReadContextualOctetString(&dec, 1, &error, &credentials, FALSE)) return FALSE; WinPrAsn1Decoder_InitMem(&dec, WINPR_ASN1_DER, credentials.data, credentials.len); if (credType == 1) { WinPrAsn1_OctetString domain = { 0 }; WinPrAsn1_OctetString username = { 0 }; WinPrAsn1_OctetString password = { 0 }; /* TSPasswordCreds */ if (!WinPrAsn1DecReadSequence(&dec, &dec2)) return FALSE; dec = dec2; /* domainName [0] OCTET STRING */ if (!WinPrAsn1DecReadContextualOctetString(&dec, 0, &error, &domain, FALSE) && error) return FALSE; /* userName [1] OCTET STRING */ if (!WinPrAsn1DecReadContextualOctetString(&dec, 1, &error, &username, FALSE) && error) return FALSE; /* password [2] OCTET STRING */ if (!WinPrAsn1DecReadContextualOctetString(&dec, 2, &error, &password, FALSE)) return FALSE; if (sspi_SetAuthIdentityWithLengthW(nla->identity, (const WCHAR*)username.data, username.len / sizeof(WCHAR), (const WCHAR*)domain.data, domain.len / sizeof(WCHAR), (const WCHAR*)password.data, password.len / sizeof(WCHAR)) < 0) return FALSE; } return TRUE; } /** * Encode TSCredentials structure. * @param nla A pointer to the NLA to use * * @return \b TRUE for success, \b FALSE otherwise */ static BOOL nla_encode_ts_credentials(rdpNla* nla) { BOOL ret = FALSE; WinPrAsn1Encoder* enc = NULL; size_t length = 0; wStream s = { 0 }; int credType = -1; WINPR_ASSERT(nla); WINPR_ASSERT(nla->rdpcontext); rdpSettings* settings = nla->rdpcontext->settings; WINPR_ASSERT(settings); enc = WinPrAsn1Encoder_New(WINPR_ASN1_DER); if (!enc) return FALSE; /* TSCredentials */ if (!WinPrAsn1EncSeqContainer(enc)) goto out; /* credType [0] INTEGER */ credType = settings->SmartcardLogon ? 2 : 1; if (!WinPrAsn1EncContextualInteger(enc, 0, credType)) goto out; /* credentials [1] OCTET STRING */ if (!WinPrAsn1EncContextualOctetStringContainer(enc, 1)) goto out; if (settings->SmartcardLogon) { struct { WinPrAsn1_tagId tag; size_t setting_id; } cspData_fields[] = { { 1, FreeRDP_CardName }, { 2, FreeRDP_ReaderName }, { 3, FreeRDP_ContainerName }, { 4, FreeRDP_CspName } }; WinPrAsn1_OctetString octet_string = { 0 }; /* TSSmartCardCreds */ if (!WinPrAsn1EncSeqContainer(enc)) goto out; /* pin [0] OCTET STRING */ size_t ss; octet_string.data = (BYTE*)freerdp_settings_get_string_as_utf16(settings, FreeRDP_Password, &ss); octet_string.len = ss * sizeof(WCHAR); const BOOL res = WinPrAsn1EncContextualOctetString(enc, 0, &octet_string) > 0; free(octet_string.data); if (!res) goto out; /* cspData [1] SEQUENCE */ if (!WinPrAsn1EncContextualSeqContainer(enc, 1)) goto out; /* keySpec [0] INTEGER */ if (!WinPrAsn1EncContextualInteger(enc, 0, freerdp_settings_get_uint32(settings, FreeRDP_KeySpec))) goto out; for (size_t i = 0; i < ARRAYSIZE(cspData_fields); i++) { size_t len; octet_string.data = (BYTE*)freerdp_settings_get_string_as_utf16( settings, cspData_fields[i].setting_id, &len); octet_string.len = len * sizeof(WCHAR); if (octet_string.len) { const BOOL res2 = WinPrAsn1EncContextualOctetString(enc, cspData_fields[i].tag, &octet_string) > 0; free(octet_string.data); if (!res2) goto out; } } /* End cspData */ if (!WinPrAsn1EncEndContainer(enc)) goto out; /* End TSSmartCardCreds */ if (!WinPrAsn1EncEndContainer(enc)) goto out; } else { WinPrAsn1_OctetString username = { 0 }; WinPrAsn1_OctetString domain = { 0 }; WinPrAsn1_OctetString password = { 0 }; /* TSPasswordCreds */ if (!WinPrAsn1EncSeqContainer(enc)) goto out; if (!settings->DisableCredentialsDelegation && nla->identity) { username.len = nla->identity->UserLength * sizeof(WCHAR); username.data = (BYTE*)nla->identity->User; domain.len = nla->identity->DomainLength * sizeof(WCHAR); domain.data = (BYTE*)nla->identity->Domain; password.len = nla->identity->PasswordLength * sizeof(WCHAR); password.data = (BYTE*)nla->identity->Password; } if (WinPrAsn1EncContextualOctetString(enc, 0, &domain) == 0) goto out; if (WinPrAsn1EncContextualOctetString(enc, 1, &username) == 0) goto out; if (WinPrAsn1EncContextualOctetString(enc, 2, &password) == 0) goto out; /* End TSPasswordCreds */ if (!WinPrAsn1EncEndContainer(enc)) goto out; } /* End credentials | End TSCredentials */ if (!WinPrAsn1EncEndContainer(enc) || !WinPrAsn1EncEndContainer(enc)) goto out; if (!WinPrAsn1EncStreamSize(enc, &length)) goto out; if (!nla_sec_buffer_alloc(&nla->tsCredentials, length)) { WLog_ERR(TAG, "sspi_SecBufferAlloc failed!"); goto out; } Stream_StaticInit(&s, (BYTE*)nla->tsCredentials.pvBuffer, length); if (WinPrAsn1EncToStream(enc, &s)) ret = TRUE; out: WinPrAsn1Encoder_Free(&enc); return ret; } static BOOL nla_encrypt_ts_credentials(rdpNla* nla) { WINPR_ASSERT(nla); if (!nla_encode_ts_credentials(nla)) return FALSE; sspi_SecBufferFree(&nla->authInfo); if (!credssp_auth_encrypt(nla->auth, &nla->tsCredentials, &nla->authInfo, NULL, nla->sendSeqNum++)) return FALSE; return TRUE; } static BOOL nla_decrypt_ts_credentials(rdpNla* nla) { WINPR_ASSERT(nla); if (nla->authInfo.cbBuffer < 1) { WLog_ERR(TAG, "nla_decrypt_ts_credentials missing authInfo buffer"); return FALSE; } sspi_SecBufferFree(&nla->tsCredentials); if (!credssp_auth_decrypt(nla->auth, &nla->authInfo, &nla->tsCredentials, nla->recvSeqNum++)) return FALSE; if (!nla_read_ts_credentials(nla, &nla->tsCredentials)) return FALSE; return TRUE; } static BOOL nla_write_octet_string(WinPrAsn1Encoder* enc, const SecBuffer* buffer, WinPrAsn1_tagId tagId, const char* msg) { BOOL res = FALSE; WINPR_ASSERT(enc); WINPR_ASSERT(buffer); WINPR_ASSERT(msg); if (buffer->cbBuffer > 0) { size_t rc = 0; WinPrAsn1_OctetString octet_string = { 0 }; WLog_DBG(TAG, " ----->> %s", msg); octet_string.data = buffer->pvBuffer; octet_string.len = buffer->cbBuffer; rc = WinPrAsn1EncContextualOctetString(enc, tagId, &octet_string); if (rc != 0) res = TRUE; } return res; } static BOOL nla_write_octet_string_free(WinPrAsn1Encoder* enc, SecBuffer* buffer, WinPrAsn1_tagId tagId, const char* msg) { const BOOL rc = nla_write_octet_string(enc, buffer, tagId, msg); sspi_SecBufferFree(buffer); return rc; } /** * Send CredSSP message. * * @param nla A pointer to the NLA to use * * @return \b TRUE for success, \b FALSE otherwise */ BOOL nla_send(rdpNla* nla) { BOOL rc = FALSE; wStream* s = NULL; size_t length = 0; WinPrAsn1Encoder* enc = NULL; WINPR_ASSERT(nla); enc = WinPrAsn1Encoder_New(WINPR_ASN1_DER); if (!enc) return FALSE; /* TSRequest */ WLog_DBG(TAG, "----->> sending..."); if (!WinPrAsn1EncSeqContainer(enc)) goto fail; /* version [0] INTEGER */ WLog_DBG(TAG, " ----->> protocol version %" PRIu32, nla->version); if (!WinPrAsn1EncContextualInteger(enc, 0, nla->version)) goto fail; /* negoTokens [1] SEQUENCE OF SEQUENCE */ if (nla_get_state(nla) <= NLA_STATE_NEGO_TOKEN && credssp_auth_have_output_token(nla->auth)) { const SecBuffer* buffer = credssp_auth_get_output_buffer(nla->auth); if (!WinPrAsn1EncContextualSeqContainer(enc, 1) || !WinPrAsn1EncSeqContainer(enc)) goto fail; /* negoToken [0] OCTET STRING */ if (!nla_write_octet_string(enc, buffer, 0, "negoToken")) goto fail; /* End negoTokens (SEQUENCE OF SEQUENCE) */ if (!WinPrAsn1EncEndContainer(enc) || !WinPrAsn1EncEndContainer(enc)) goto fail; } /* authInfo [2] OCTET STRING */ if (nla->authInfo.cbBuffer > 0) { if (!nla_write_octet_string_free(enc, &nla->authInfo, 2, "auth info")) goto fail; } /* pubKeyAuth [3] OCTET STRING */ if (nla->pubKeyAuth.cbBuffer > 0) { if (!nla_write_octet_string_free(enc, &nla->pubKeyAuth, 3, "public key auth")) goto fail; } /* errorCode [4] INTEGER */ if (nla->errorCode && nla->peerVersion >= 3 && nla->peerVersion != 5) { WLog_DBG(TAG, " ----->> error code %s 0x%08" PRIx32, NtStatus2Tag(nla->errorCode), nla->errorCode); if (!WinPrAsn1EncContextualInteger(enc, 4, nla->errorCode)) goto fail; } /* clientNonce [5] OCTET STRING */ if (!nla->server && nla->ClientNonce.cbBuffer > 0) { if (!nla_write_octet_string(enc, &nla->ClientNonce, 5, "client nonce")) goto fail; } /* End TSRequest */ if (!WinPrAsn1EncEndContainer(enc)) goto fail; if (!WinPrAsn1EncStreamSize(enc, &length)) goto fail; s = Stream_New(NULL, length); if (!s) goto fail; if (!WinPrAsn1EncToStream(enc, s)) goto fail; WLog_DBG(TAG, "[%" PRIuz " bytes]", length); if (transport_write(nla->transport, s) < 0) goto fail; rc = TRUE; fail: Stream_Free(s, TRUE); WinPrAsn1Encoder_Free(&enc); return rc; } static int nla_decode_ts_request(rdpNla* nla, wStream* s) { WinPrAsn1Decoder dec = { 0 }; WinPrAsn1Decoder dec2 = { 0 }; BOOL error = FALSE; WinPrAsn1_tagId tag = { 0 }; WinPrAsn1_INTEGER val = { 0 }; UINT32 version = 0; WINPR_ASSERT(nla); WINPR_ASSERT(s); WinPrAsn1Decoder_Init(&dec, WINPR_ASN1_DER, s); WLog_DBG(TAG, "<<----- receiving..."); /* TSRequest */ const size_t offset = WinPrAsn1DecReadSequence(&dec, &dec2); if (offset == 0) return -1; dec = dec2; /* version [0] INTEGER */ if (WinPrAsn1DecReadContextualInteger(&dec, 0, &error, &val) == 0) return -1; if (!Stream_SafeSeek(s, offset)) return -1; version = (UINT)val; WLog_DBG(TAG, " <<----- protocol version %" PRIu32, version); if (nla->peerVersion == 0) nla->peerVersion = version; /* if the peer suddenly changed its version - kick it */ if (nla->peerVersion != version) { WLog_ERR(TAG, "CredSSP peer changed protocol version from %" PRIu32 " to %" PRIu32, nla->peerVersion, version); return -1; } while (WinPrAsn1DecReadContextualTag(&dec, &tag, &dec2) != 0) { WinPrAsn1Decoder dec3 = { 0 }; WinPrAsn1_OctetString octet_string = { 0 }; switch (tag) { case 1: WLog_DBG(TAG, " <<----- nego token"); /* negoTokens [1] SEQUENCE OF SEQUENCE */ if ((WinPrAsn1DecReadSequence(&dec2, &dec3) == 0) || (WinPrAsn1DecReadSequence(&dec3, &dec2) == 0)) return -1; /* negoToken [0] OCTET STRING */ if ((WinPrAsn1DecReadContextualOctetString(&dec2, 0, &error, &octet_string, FALSE) == 0) && error) return -1; if (!nla_sec_buffer_alloc_from_data(&nla->negoToken, octet_string.data, 0, octet_string.len)) return -1; break; case 2: WLog_DBG(TAG, " <<----- auth info"); /* authInfo [2] OCTET STRING */ if (WinPrAsn1DecReadOctetString(&dec2, &octet_string, FALSE) == 0) return -1; if (!nla_sec_buffer_alloc_from_data(&nla->authInfo, octet_string.data, 0, octet_string.len)) return -1; break; case 3: WLog_DBG(TAG, " <<----- public key auth"); /* pubKeyAuth [3] OCTET STRING */ if (WinPrAsn1DecReadOctetString(&dec2, &octet_string, FALSE) == 0) return -1; if (!nla_sec_buffer_alloc_from_data(&nla->pubKeyAuth, octet_string.data, 0, octet_string.len)) return -1; break; case 4: /* errorCode [4] INTEGER */ if (WinPrAsn1DecReadInteger(&dec2, &val) == 0) return -1; nla->errorCode = (UINT)val; WLog_DBG(TAG, " <<----- error code %s 0x%08" PRIx32, NtStatus2Tag(nla->errorCode), nla->errorCode); break; case 5: WLog_DBG(TAG, " <<----- client nonce"); /* clientNonce [5] OCTET STRING */ if (WinPrAsn1DecReadOctetString(&dec2, &octet_string, FALSE) == 0) return -1; if (!nla_sec_buffer_alloc_from_data(&nla->ClientNonce, octet_string.data, 0, octet_string.len)) return -1; break; default: return -1; } } return 1; } int nla_recv_pdu(rdpNla* nla, wStream* s) { WINPR_ASSERT(nla); WINPR_ASSERT(s); if (nla_decode_ts_request(nla, s) < 1) return -1; if (nla->errorCode) { UINT32 code; switch (nla->errorCode) { case STATUS_PASSWORD_MUST_CHANGE: code = FREERDP_ERROR_CONNECT_PASSWORD_MUST_CHANGE; break; case STATUS_PASSWORD_EXPIRED: code = FREERDP_ERROR_CONNECT_PASSWORD_EXPIRED; break; case STATUS_ACCOUNT_DISABLED: code = FREERDP_ERROR_CONNECT_ACCOUNT_DISABLED; break; case STATUS_LOGON_FAILURE: code = FREERDP_ERROR_CONNECT_LOGON_FAILURE; break; case STATUS_WRONG_PASSWORD: code = FREERDP_ERROR_CONNECT_WRONG_PASSWORD; break; case STATUS_ACCESS_DENIED: code = FREERDP_ERROR_CONNECT_ACCESS_DENIED; break; case STATUS_ACCOUNT_RESTRICTION: code = FREERDP_ERROR_CONNECT_ACCOUNT_RESTRICTION; break; case STATUS_ACCOUNT_LOCKED_OUT: code = FREERDP_ERROR_CONNECT_ACCOUNT_LOCKED_OUT; break; case STATUS_ACCOUNT_EXPIRED: code = FREERDP_ERROR_CONNECT_ACCOUNT_EXPIRED; break; case STATUS_LOGON_TYPE_NOT_GRANTED: code = FREERDP_ERROR_CONNECT_LOGON_TYPE_NOT_GRANTED; break; default: WLog_ERR(TAG, "SPNEGO failed with NTSTATUS: 0x%08" PRIX32 "", nla->errorCode); code = FREERDP_ERROR_AUTHENTICATION_FAILED; break; } freerdp_set_last_error_log(nla->rdpcontext, code); return -1; } return nla_client_recv(nla); } int nla_server_recv(rdpNla* nla) { int status = -1; WINPR_ASSERT(nla); wStream* s = nla_server_recv_stream(nla); if (!s) goto fail; status = nla_decode_ts_request(nla, s); fail: Stream_Free(s, TRUE); return status; } /** * Create new CredSSP state machine. * * @param context A pointer to the rdp context to use * @param transport A pointer to the transport to use * * @return new CredSSP state machine. */ rdpNla* nla_new(rdpContext* context, rdpTransport* transport) { WINPR_ASSERT(transport); WINPR_ASSERT(context); rdpSettings* settings = context->settings; WINPR_ASSERT(settings); rdpNla* nla = (rdpNla*)calloc(1, sizeof(rdpNla)); if (!nla) return NULL; nla->rdpcontext = context; nla->server = settings->ServerMode; nla->transport = transport; nla->sendSeqNum = 0; nla->recvSeqNum = 0; nla->version = 6; nla->identity = calloc(1, sizeof(SEC_WINNT_AUTH_IDENTITY)); if (!nla->identity) goto cleanup; nla->auth = credssp_auth_new(context); if (!nla->auth) goto cleanup; /* init to 0 or we end up freeing a bad pointer if the alloc fails */ if (!nla_sec_buffer_alloc(&nla->ClientNonce, NonceLength)) goto cleanup; /* generate random 32-byte nonce */ if (winpr_RAND(nla->ClientNonce.pvBuffer, NonceLength) < 0) goto cleanup; return nla; cleanup: credssp_auth_free(nla->auth); free(nla->identity); nla_free(nla); return NULL; } /** * Free CredSSP state machine. * @param nla The NLA instance to free */ void nla_free(rdpNla* nla) { if (!nla) return; smartcardCertInfo_Free(nla->smartcardCert); nla_buffer_free(nla); sspi_SecBufferFree(&nla->tsCredentials); credssp_auth_free(nla->auth); sspi_FreeAuthIdentity(nla->identity); free(nla->pkinitArgs); free(nla->identity); free(nla); } SEC_WINNT_AUTH_IDENTITY* nla_get_identity(rdpNla* nla) { if (!nla) return NULL; return nla->identity; } NLA_STATE nla_get_state(rdpNla* nla) { if (!nla) return NLA_STATE_FINAL; return nla->state; } BOOL nla_set_state(rdpNla* nla, NLA_STATE state) { if (!nla) return FALSE; WLog_DBG(TAG, "-- %s\t--> %s", nla_get_state_str(nla->state), nla_get_state_str(state)); nla->state = state; return TRUE; } BOOL nla_set_service_principal(rdpNla* nla, const char* service, const char* hostname) { if (!credssp_auth_set_spn(nla->auth, service, hostname)) return FALSE; return TRUE; } BOOL nla_impersonate(rdpNla* nla) { return credssp_auth_impersonate(nla->auth); } BOOL nla_revert_to_self(rdpNla* nla) { return credssp_auth_revert_to_self(nla->auth); } const char* nla_get_state_str(NLA_STATE state) { switch (state) { case NLA_STATE_INITIAL: return "NLA_STATE_INITIAL"; case NLA_STATE_NEGO_TOKEN: return "NLA_STATE_NEGO_TOKEN"; case NLA_STATE_PUB_KEY_AUTH: return "NLA_STATE_PUB_KEY_AUTH"; case NLA_STATE_AUTH_INFO: return "NLA_STATE_AUTH_INFO"; case NLA_STATE_POST_NEGO: return "NLA_STATE_POST_NEGO"; case NLA_STATE_FINAL: return "NLA_STATE_FINAL"; default: return "UNKNOWN"; } } DWORD nla_get_error(rdpNla* nla) { if (!nla) return ERROR_INTERNAL_ERROR; return nla->errorCode; } UINT32 nla_get_sspi_error(rdpNla* nla) { WINPR_ASSERT(nla); return credssp_auth_sspi_error(nla->auth); }