/* * FreeRDP: A Remote Desktop Protocol Implementation * Connection Sequence * * Copyright 2011 Marc-Andre Moreau * * 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. */ #ifdef HAVE_CONFIG_H #include "config.h" #endif #include "info.h" #include "input.h" #include "connection.h" #include "transport.h" #include #include /** * Connection Sequence\n * client server\n * | |\n * |-----------------------X.224 Connection Request PDU--------------------->|\n * |<----------------------X.224 Connection Confirm PDU----------------------|\n * |-------MCS Connect-Initial PDU with GCC Conference Create Request------->|\n * |<-----MCS Connect-Response PDU with GCC Conference Create Response-------|\n * |------------------------MCS Erect Domain Request PDU-------------------->|\n * |------------------------MCS Attach User Request PDU--------------------->|\n * |<-----------------------MCS Attach User Confirm PDU----------------------|\n * |------------------------MCS Channel Join Request PDU-------------------->|\n * |<-----------------------MCS Channel Join Confirm PDU---------------------|\n * |----------------------------Security Exchange PDU----------------------->|\n * |-------------------------------Client Info PDU-------------------------->|\n * |<---------------------License Error PDU - Valid Client-------------------|\n * |<-----------------------------Demand Active PDU--------------------------|\n * |------------------------------Confirm Active PDU------------------------>|\n * |-------------------------------Synchronize PDU-------------------------->|\n * |---------------------------Control PDU - Cooperate---------------------->|\n * |------------------------Control PDU - Request Control------------------->|\n * |--------------------------Persistent Key List PDU(s)-------------------->|\n * |--------------------------------Font List PDU--------------------------->|\n * |<------------------------------Synchronize PDU---------------------------|\n * |<--------------------------Control PDU - Cooperate-----------------------|\n * |<-----------------------Control PDU - Granted Control--------------------|\n * |<-------------------------------Font Map PDU-----------------------------|\n * */ /** * Establish RDP Connection based on the settings given in the 'rdp' parameter. * @msdn{cc240452} * @param rdp RDP module * @return true if the connection succeeded. FALSE otherwise. */ BOOL rdp_client_connect(rdpRdp* rdp) { rdpSettings* settings = rdp->settings; nego_init(rdp->nego); nego_set_target(rdp->nego, settings->ServerHostname, settings->ServerPort); if (settings->GatewayUsageMethod) { char* user; char* domain; char* cookie; int user_length; int domain_length; int cookie_length; user = settings->Username; user_length = strlen(settings->Username); if (settings->Domain) domain = settings->Domain; else domain = settings->ComputerName; domain_length = strlen(domain); cookie_length = domain_length + 1 + user_length; cookie = (char*) malloc(cookie_length + 1); CopyMemory(cookie, domain, domain_length); CharUpperBuffA(cookie, domain_length); cookie[domain_length] = '\\'; CopyMemory(&cookie[domain_length + 1], user, user_length); cookie[cookie_length] = '\0'; nego_set_cookie(rdp->nego, cookie); free(cookie); settings->RdpSecurity = TRUE; settings->TlsSecurity = FALSE; settings->NlaSecurity = FALSE; settings->ExtSecurity = FALSE; //settings->TlsSecurity = TRUE; //settings->NlaSecurity = TRUE; } else { nego_set_cookie(rdp->nego, settings->Username); } nego_set_send_preconnection_pdu(rdp->nego, settings->SendPreconnectionPdu); nego_set_preconnection_id(rdp->nego, settings->PreconnectionId); nego_set_preconnection_blob(rdp->nego, settings->PreconnectionBlob); nego_set_negotiation_enabled(rdp->nego, settings->NegotiateSecurityLayer); nego_enable_rdp(rdp->nego, settings->RdpSecurity); nego_enable_tls(rdp->nego, settings->TlsSecurity); nego_enable_nla(rdp->nego, settings->NlaSecurity); nego_enable_ext(rdp->nego, settings->ExtSecurity); if (settings->MstscCookieMode) settings->CookieMaxLength = MSTSC_COOKIE_MAX_LENGTH; nego_set_cookie_max_length(rdp->nego, settings->CookieMaxLength); if (settings->LoadBalanceInfo) nego_set_routing_token(rdp->nego, settings->LoadBalanceInfo, settings->LoadBalanceInfoLength); if (!nego_connect(rdp->nego)) { fprintf(stderr, "Error: protocol security negotiation or connection failure\n"); return FALSE; } if ((rdp->nego->selected_protocol & PROTOCOL_TLS) || (rdp->nego->selected_protocol == PROTOCOL_RDP)) { if ((settings->Username != NULL) && ((settings->Password != NULL) || (settings->RedirectionPassword != NULL && settings->RedirectionPasswordLength > 0))) settings->AutoLogonEnabled = TRUE; } rdp_set_blocking_mode(rdp, FALSE); rdp->state = CONNECTION_STATE_NEGO; rdp->finalize_sc_pdus = 0; if (!mcs_send_connect_initial(rdp->mcs)) { if (!connectErrorCode) { connectErrorCode = MCSCONNECTINITIALERROR; } fprintf(stderr, "Error: unable to send MCS Connect Initial\n"); return FALSE; } while (rdp->state != CONNECTION_STATE_ACTIVE) { if (rdp_check_fds(rdp) < 0) return FALSE; } return TRUE; } BOOL rdp_client_disconnect(rdpRdp* rdp) { return transport_disconnect(rdp->transport); } BOOL rdp_client_redirect(rdpRdp* rdp) { rdpSettings* settings = rdp->settings; rdpRedirection* redirection = rdp->redirection; rdp_client_disconnect(rdp); /* FIXME: this is a subset of rdp_free */ crypto_rc4_free(rdp->rc4_decrypt_key); crypto_rc4_free(rdp->rc4_encrypt_key); crypto_des3_free(rdp->fips_encrypt); crypto_des3_free(rdp->fips_decrypt); crypto_hmac_free(rdp->fips_hmac); mcs_free(rdp->mcs); nego_free(rdp->nego); license_free(rdp->license); transport_free(rdp->transport); free(settings->ServerRandom); free(settings->ServerCertificate); free(settings->ClientAddress); rdp->transport = transport_new(settings); rdp->license = license_new(rdp); rdp->nego = nego_new(rdp->transport); rdp->mcs = mcs_new(rdp->transport); rdp->transport->layer = TRANSPORT_LAYER_TCP; settings->RedirectedSessionId = redirection->sessionID; if (redirection->flags & LB_LOAD_BALANCE_INFO) { nego_set_routing_token(rdp->nego, redirection->LoadBalanceInfo, redirection->LoadBalanceInfoLength); } else { if (redirection->flags & LB_TARGET_NET_ADDRESS) { free(settings->ServerHostname); settings->ServerHostname = _strdup(redirection->targetNetAddress.ascii); } else if (redirection->flags & LB_TARGET_FQDN) { free(settings->ServerHostname); settings->ServerHostname = _strdup(redirection->targetFQDN.ascii); } else if (redirection->flags & LB_TARGET_NETBIOS_NAME) { free(settings->ServerHostname); settings->ServerHostname = _strdup(redirection->targetNetBiosName.ascii); } } if (redirection->flags & LB_USERNAME) { free(settings->Username); settings->Username = _strdup(redirection->username.ascii); } if (redirection->flags & LB_DOMAIN) { free(settings->Domain); settings->Domain = _strdup(redirection->domain.ascii); } if (redirection->flags & LB_PASSWORD) { settings->RedirectionPassword = redirection->PasswordCookie; settings->RedirectionPasswordLength = redirection->PasswordCookieLength; } return rdp_client_connect(rdp); } static BOOL rdp_client_establish_keys(rdpRdp* rdp) { BYTE* mod; BYTE* exp; wStream* s; UINT32 length; UINT32 key_len; BYTE crypt_client_random[256 + 8]; BYTE client_random[CLIENT_RANDOM_LENGTH]; if (rdp->settings->DisableEncryption == FALSE) { /* no RDP encryption */ return TRUE; } /* encrypt client random */ ZeroMemory(crypt_client_random, sizeof(crypt_client_random)); crypto_nonce(client_random, sizeof(client_random)); key_len = rdp->settings->RdpServerCertificate->cert_info.ModulusLength; mod = rdp->settings->RdpServerCertificate->cert_info.Modulus; exp = rdp->settings->RdpServerCertificate->cert_info.exponent; crypto_rsa_public_encrypt(client_random, sizeof(client_random), key_len, mod, exp, crypt_client_random); /* send crypt client random to server */ length = RDP_PACKET_HEADER_MAX_LENGTH + RDP_SECURITY_HEADER_LENGTH + 4 + key_len + 8; s = Stream_New(NULL, length); rdp_write_header(rdp, s, length, MCS_GLOBAL_CHANNEL_ID); rdp_write_security_header(s, SEC_EXCHANGE_PKT); length = key_len + 8; Stream_Write_UINT32(s, length); Stream_Write(s, crypt_client_random, length); Stream_SealLength(s); if (transport_write(rdp->mcs->transport, s) < 0) { return FALSE; } Stream_Free(s, TRUE); /* now calculate encrypt / decrypt and update keys */ if (!security_establish_keys(client_random, rdp)) { return FALSE; } rdp->do_crypt = TRUE; if (rdp->settings->SaltedChecksum) rdp->do_secure_checksum = TRUE; if (rdp->settings->EncryptionMethods == ENCRYPTION_METHOD_FIPS) { BYTE fips_ivec[8] = { 0x12, 0x34, 0x56, 0x78, 0x90, 0xAB, 0xCD, 0xEF }; rdp->fips_encrypt = crypto_des3_encrypt_init(rdp->fips_encrypt_key, fips_ivec); rdp->fips_decrypt = crypto_des3_decrypt_init(rdp->fips_decrypt_key, fips_ivec); rdp->fips_hmac = crypto_hmac_new(); return TRUE; } rdp->rc4_decrypt_key = crypto_rc4_init(rdp->decrypt_key, rdp->rc4_key_len); rdp->rc4_encrypt_key = crypto_rc4_init(rdp->encrypt_key, rdp->rc4_key_len); return TRUE; } static BOOL rdp_server_establish_keys(rdpRdp* rdp, wStream* s) { BYTE client_random[64]; /* Should be only 32 after successful decryption, but on failure might take up to 64 bytes. */ BYTE crypt_client_random[256 + 8]; UINT32 rand_len, key_len; UINT16 channel_id, length, sec_flags; BYTE* mod; BYTE* priv_exp; if (rdp->settings->DisableEncryption == FALSE) { /* No RDP Security. */ return TRUE; } if (!rdp_read_header(rdp, s, &length, &channel_id)) { fprintf(stderr, "rdp_server_establish_keys: invalid RDP header\n"); return FALSE; } if (!rdp_read_security_header(s, &sec_flags)) return FALSE; if ((sec_flags & SEC_EXCHANGE_PKT) == 0) { fprintf(stderr, "rdp_server_establish_keys: missing SEC_EXCHANGE_PKT in security header\n"); return FALSE; } if(Stream_GetRemainingLength(s) < 4) return FALSE; Stream_Read_UINT32(s, rand_len); if(Stream_GetRemainingLength(s) < rand_len + 8) /* include 8 bytes of padding */ return FALSE; key_len = rdp->settings->RdpServerRsaKey->ModulusLength; if (rand_len != key_len + 8) { fprintf(stderr, "rdp_server_establish_keys: invalid encrypted client random length\n"); return FALSE; } memset(crypt_client_random, 0, sizeof(crypt_client_random)); Stream_Read(s, crypt_client_random, rand_len); /* 8 zero bytes of padding */ Stream_Seek(s, 8); mod = rdp->settings->RdpServerRsaKey->Modulus; priv_exp = rdp->settings->RdpServerRsaKey->PrivateExponent; crypto_rsa_private_decrypt(crypt_client_random, rand_len - 8, key_len, mod, priv_exp, client_random); /* now calculate encrypt / decrypt and update keys */ if (!security_establish_keys(client_random, rdp)) { return FALSE; } rdp->do_crypt = TRUE; if (rdp->settings->SaltedChecksum) rdp->do_secure_checksum = TRUE; if (rdp->settings->EncryptionMethods == ENCRYPTION_METHOD_FIPS) { BYTE fips_ivec[8] = { 0x12, 0x34, 0x56, 0x78, 0x90, 0xAB, 0xCD, 0xEF }; rdp->fips_encrypt = crypto_des3_encrypt_init(rdp->fips_encrypt_key, fips_ivec); rdp->fips_decrypt = crypto_des3_decrypt_init(rdp->fips_decrypt_key, fips_ivec); rdp->fips_hmac = crypto_hmac_new(); return TRUE; } rdp->rc4_decrypt_key = crypto_rc4_init(rdp->decrypt_key, rdp->rc4_key_len); rdp->rc4_encrypt_key = crypto_rc4_init(rdp->encrypt_key, rdp->rc4_key_len); return TRUE; } BOOL rdp_client_connect_mcs_connect_response(rdpRdp* rdp, wStream* s) { if (!mcs_recv_connect_response(rdp->mcs, s)) { fprintf(stderr, "rdp_client_connect_mcs_connect_response: mcs_recv_connect_response failed\n"); return FALSE; } if (!mcs_send_erect_domain_request(rdp->mcs)) return FALSE; if (!mcs_send_attach_user_request(rdp->mcs)) return FALSE; rdp->state = CONNECTION_STATE_MCS_ATTACH_USER; return TRUE; } BOOL rdp_client_connect_mcs_attach_user_confirm(rdpRdp* rdp, wStream* s) { if (!mcs_recv_attach_user_confirm(rdp->mcs, s)) return FALSE; if (!mcs_send_channel_join_request(rdp->mcs, rdp->mcs->user_id)) return FALSE; rdp->state = CONNECTION_STATE_MCS_CHANNEL_JOIN; return TRUE; } BOOL rdp_client_connect_mcs_channel_join_confirm(rdpRdp* rdp, wStream* s) { int i; UINT16 channel_id; BOOL all_joined = TRUE; if (!mcs_recv_channel_join_confirm(rdp->mcs, s, &channel_id)) return FALSE; if (!rdp->mcs->user_channel_joined) { if (channel_id != rdp->mcs->user_id) return FALSE; rdp->mcs->user_channel_joined = TRUE; if (!mcs_send_channel_join_request(rdp->mcs, MCS_GLOBAL_CHANNEL_ID)) return FALSE; } else if (!rdp->mcs->global_channel_joined) { if (channel_id != MCS_GLOBAL_CHANNEL_ID) return FALSE; rdp->mcs->global_channel_joined = TRUE; if (rdp->settings->ChannelCount > 0) { if (!mcs_send_channel_join_request(rdp->mcs, rdp->settings->ChannelDefArray[0].ChannelId)) return FALSE; all_joined = FALSE; } } else { for (i = 0; i < rdp->settings->ChannelCount; i++) { if (rdp->settings->ChannelDefArray[i].joined) continue; if (rdp->settings->ChannelDefArray[i].ChannelId != channel_id) return FALSE; rdp->settings->ChannelDefArray[i].joined = TRUE; break; } if (i + 1 < rdp->settings->ChannelCount) { if (!mcs_send_channel_join_request(rdp->mcs, rdp->settings->ChannelDefArray[i + 1].ChannelId)) return FALSE; all_joined = FALSE; } } if (rdp->mcs->user_channel_joined && rdp->mcs->global_channel_joined && all_joined) { if (!rdp_client_establish_keys(rdp)) return FALSE; if (!rdp_send_client_info(rdp)) return FALSE; rdp->state = CONNECTION_STATE_LICENSE; } return TRUE; } BOOL rdp_client_connect_license(rdpRdp* rdp, wStream* s) { if (!license_recv(rdp->license, s)) return FALSE; if (rdp->license->state == LICENSE_STATE_ABORTED) { fprintf(stderr, "license connection sequence aborted.\n"); return FALSE; } if (rdp->license->state == LICENSE_STATE_COMPLETED) { rdp->state = CONNECTION_STATE_CAPABILITY; } return TRUE; } BOOL rdp_client_connect_demand_active(rdpRdp* rdp, wStream* s) { BYTE* mark; UINT16 width; UINT16 height; width = rdp->settings->DesktopWidth; height = rdp->settings->DesktopHeight; Stream_GetPointer(s, mark); if (!rdp_recv_demand_active(rdp, s)) { UINT16 channelId; Stream_SetPointer(s, mark); rdp_recv_get_active_header(rdp, s, &channelId); /* Was Stream_Seek(s, RDP_PACKET_HEADER_MAX_LENGTH); * but the headers aren't always that length, * so that could result in a bad offset. */ if (rdp_recv_out_of_sequence_pdu(rdp, s) != TRUE) return FALSE; return TRUE; } if (rdp->disconnect) return TRUE; if (!rdp_send_confirm_active(rdp)) return FALSE; input_register_client_callbacks(rdp->input); /** * The server may request a different desktop size during Deactivation-Reactivation sequence. * In this case, the UI should be informed and do actual window resizing at this point. */ if (width != rdp->settings->DesktopWidth || height != rdp->settings->DesktopHeight) { IFCALL(rdp->update->DesktopResize, rdp->update->context); } rdp->state = CONNECTION_STATE_FINALIZATION; update_reset_state(rdp->update); return rdp_client_connect_finalize(rdp); } BOOL rdp_client_connect_finalize(rdpRdp* rdp) { /** * [MS-RDPBCGR] 1.3.1.1 - 8. * The client-to-server PDUs sent during this phase have no dependencies on any of the server-to- * client PDUs; they may be sent as a single batch, provided that sequencing is maintained. */ if (!rdp_send_client_synchronize_pdu(rdp)) return FALSE; if (!rdp_send_client_control_pdu(rdp, CTRLACTION_COOPERATE)) return FALSE; if (!rdp_send_client_control_pdu(rdp, CTRLACTION_REQUEST_CONTROL)) return FALSE; if (!rdp_send_client_persistent_key_list_pdu(rdp)) return FALSE; if (!rdp_send_client_font_list_pdu(rdp, FONTLIST_FIRST | FONTLIST_LAST)) return FALSE; return TRUE; } BOOL rdp_server_accept_nego(rdpRdp* rdp, wStream* s) { BOOL status; rdpSettings* settings = rdp->settings; transport_set_blocking_mode(rdp->transport, TRUE); if (!nego_read_request(rdp->nego, s)) return FALSE; rdp->nego->selected_protocol = 0; fprintf(stderr, "Client Security: NLA:%d TLS:%d RDP:%d\n", (rdp->nego->requested_protocols & PROTOCOL_NLA) ? 1 : 0, (rdp->nego->requested_protocols & PROTOCOL_TLS) ? 1 : 0, (rdp->nego->requested_protocols == PROTOCOL_RDP) ? 1: 0); fprintf(stderr, "Server Security: NLA:%d TLS:%d RDP:%d\n", settings->NlaSecurity, settings->TlsSecurity, settings->RdpSecurity); if ((settings->NlaSecurity) && (rdp->nego->requested_protocols & PROTOCOL_NLA)) { rdp->nego->selected_protocol = PROTOCOL_NLA; } else if ((settings->TlsSecurity) && (rdp->nego->requested_protocols & PROTOCOL_TLS)) { rdp->nego->selected_protocol = PROTOCOL_TLS; } else if ((settings->RdpSecurity) && (rdp->nego->selected_protocol == PROTOCOL_RDP)) { rdp->nego->selected_protocol = PROTOCOL_RDP; } else { fprintf(stderr, "Protocol security negotiation failure\n"); } fprintf(stderr, "Negotiated Security: NLA:%d TLS:%d RDP:%d\n", (rdp->nego->selected_protocol & PROTOCOL_NLA) ? 1 : 0, (rdp->nego->selected_protocol & PROTOCOL_TLS) ? 1 : 0, (rdp->nego->selected_protocol == PROTOCOL_RDP) ? 1: 0); if (!nego_send_negotiation_response(rdp->nego)) return FALSE; status = FALSE; if (rdp->nego->selected_protocol & PROTOCOL_NLA) status = transport_accept_nla(rdp->transport); else if (rdp->nego->selected_protocol & PROTOCOL_TLS) status = transport_accept_tls(rdp->transport); else if (rdp->nego->selected_protocol == PROTOCOL_RDP) /* 0 */ status = transport_accept_rdp(rdp->transport); if (!status) return FALSE; transport_set_blocking_mode(rdp->transport, FALSE); rdp->state = CONNECTION_STATE_NEGO; return TRUE; } BOOL rdp_server_accept_mcs_connect_initial(rdpRdp* rdp, wStream* s) { int i; if (!mcs_recv_connect_initial(rdp->mcs, s)) return FALSE; fprintf(stderr, "Accepted client: %s\n", rdp->settings->ClientHostname); fprintf(stderr, "Accepted channels:"); for (i = 0; i < rdp->settings->ChannelCount; i++) { fprintf(stderr, " %s", rdp->settings->ChannelDefArray[i].Name); } fprintf(stderr, "\n"); if (!mcs_send_connect_response(rdp->mcs)) return FALSE; rdp->state = CONNECTION_STATE_MCS_CONNECT; return TRUE; } BOOL rdp_server_accept_mcs_erect_domain_request(rdpRdp* rdp, wStream* s) { if (!mcs_recv_erect_domain_request(rdp->mcs, s)) return FALSE; rdp->state = CONNECTION_STATE_MCS_ERECT_DOMAIN; return TRUE; } BOOL rdp_server_accept_mcs_attach_user_request(rdpRdp* rdp, wStream* s) { if (!mcs_recv_attach_user_request(rdp->mcs, s)) return FALSE; if (!mcs_send_attach_user_confirm(rdp->mcs)) return FALSE; rdp->state = CONNECTION_STATE_MCS_ATTACH_USER; return TRUE; } BOOL rdp_server_accept_mcs_channel_join_request(rdpRdp* rdp, wStream* s) { int i; UINT16 channel_id; BOOL all_joined = TRUE; if (!mcs_recv_channel_join_request(rdp->mcs, s, &channel_id)) return FALSE; if (!mcs_send_channel_join_confirm(rdp->mcs, channel_id)) return FALSE; if (channel_id == rdp->mcs->user_id) rdp->mcs->user_channel_joined = TRUE; else if (channel_id == MCS_GLOBAL_CHANNEL_ID) rdp->mcs->global_channel_joined = TRUE; for (i = 0; i < rdp->settings->ChannelCount; i++) { if (rdp->settings->ChannelDefArray[i].ChannelId == channel_id) rdp->settings->ChannelDefArray[i].joined = TRUE; if (!rdp->settings->ChannelDefArray[i].joined) all_joined = FALSE; } if (rdp->mcs->user_channel_joined && rdp->mcs->global_channel_joined && all_joined) rdp->state = CONNECTION_STATE_MCS_CHANNEL_JOIN; return TRUE; } BOOL rdp_server_accept_client_keys(rdpRdp* rdp, wStream* s) { if (!rdp_server_establish_keys(rdp, s)) return FALSE; rdp->state = CONNECTION_STATE_ESTABLISH_KEYS; return TRUE; } BOOL rdp_server_accept_client_info(rdpRdp* rdp, wStream* s) { if (!rdp_recv_client_info(rdp, s)) return FALSE; if (!license_send_valid_client_error_packet(rdp->license)) return FALSE; rdp->state = CONNECTION_STATE_LICENSE; return TRUE; } BOOL rdp_server_accept_confirm_active(rdpRdp* rdp, wStream* s) { if (!rdp_recv_confirm_active(rdp, s)) return FALSE; rdp->state = CONNECTION_STATE_ACTIVE; update_reset_state(rdp->update); if (!rdp_send_server_synchronize_pdu(rdp)) return FALSE; if (!rdp_send_server_control_cooperate_pdu(rdp)) return FALSE; return TRUE; } BOOL rdp_server_reactivate(rdpRdp* rdp) { if (!rdp_send_deactivate_all(rdp)) return FALSE; rdp->state = CONNECTION_STATE_LICENSE; if (!rdp_send_demand_active(rdp)) return FALSE; return TRUE; }