/* -*- c-basic-offset: 8 -*- rdesktop: A Remote Desktop Protocol client. RDP licensing negotiation Copyright (C) Matthew Chapman 1999-2008 Copyright (C) Thomas Uhle 2011 Copyright (C) Henrik Andersson 2014 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 . */ #include "precomp.h" void * rdssl_rc4_info_create(void); void rdssl_rc4_info_delete(void * rc4_info); void rdssl_rc4_set_key(void * rc4_info, char * key, int len); void rdssl_rc4_crypt(void * rc4_info, char * in_data, char * out_data, int len); int rdssl_mod_exp(char* out, int out_len, char* in, int in_len, char* mod, int mod_len, char* exp, int exp_len); extern char g_username[256]; extern char g_hostname[256]; extern RDP_VERSION g_rdp_version; static uint8 g_licence_key[16]; static uint8 g_licence_sign_key[16]; RD_BOOL g_licence_issued = False; RD_BOOL g_licence_error_result = False; /* Generate a session key and RC4 keys, given client and server randoms */ static void licence_generate_keys(uint8 * client_random, uint8 * server_random, uint8 * pre_master_secret) { uint8 master_secret[48]; uint8 key_block[48]; /* Generate master secret and then key material */ sec_hash_48(master_secret, pre_master_secret, client_random, server_random, 'A'); sec_hash_48(key_block, master_secret, server_random, client_random, 'A'); /* Store first 16 bytes of session key as MAC secret */ memcpy(g_licence_sign_key, key_block, 16); /* Generate RC4 key from next 16 bytes */ sec_hash_16(g_licence_key, &key_block[16], client_random, server_random); } static void licence_generate_hwid(uint8 * hwid) { buf_out_uint32(hwid, 2); strncpy((char *) (hwid + 4), g_hostname, LICENCE_HWID_SIZE - 4); } /* Send a lincece info packet to server */ static void licence_info(uint8 * client_random, uint8 * rsa_data, uint8 * licence_data, int licence_size, uint8 * hwid, uint8 * signature) { uint32 sec_flags = SEC_LICENSE_PKT; uint16 length = 24 + SEC_RANDOM_SIZE + SEC_MODULUS_SIZE + SEC_PADDING_SIZE + licence_size + LICENCE_HWID_SIZE + LICENCE_SIGNATURE_SIZE; STREAM s; s = sec_init(sec_flags, length + 2); out_uint8(s, LICENCE_TAG_LICENCE_INFO); out_uint8(s, ((g_rdp_version >= RDP_V5) ? 3 : 2)); /* version */ out_uint16_le(s, length); out_uint32_le(s, 1); out_uint16(s, 0); out_uint16_le(s, 0x0201); out_uint8p(s, client_random, SEC_RANDOM_SIZE); out_uint16_le(s, 2); out_uint16_le(s, (SEC_MODULUS_SIZE + SEC_PADDING_SIZE)); out_uint8p(s, rsa_data, SEC_MODULUS_SIZE); out_uint8s(s, SEC_PADDING_SIZE); out_uint16_le(s, 1); out_uint16_le(s, licence_size); out_uint8p(s, licence_data, licence_size); out_uint16_le(s, 1); out_uint16_le(s, LICENCE_HWID_SIZE); out_uint8p(s, hwid, LICENCE_HWID_SIZE); out_uint8p(s, signature, LICENCE_SIGNATURE_SIZE); s_mark_end(s); sec_send(s, sec_flags); } /* Send a new licence request packet */ static void licence_send_new_licence_request(uint8 * client_random, uint8 * rsa_data, char *user, char *host) { uint32 sec_flags = SEC_LICENSE_PKT; uint16 userlen = strlen(user) + 1; uint16 hostlen = strlen(host) + 1; uint16 length = 24 + SEC_RANDOM_SIZE + SEC_MODULUS_SIZE + SEC_PADDING_SIZE + userlen + hostlen; STREAM s; s = sec_init(sec_flags, length + 2); out_uint8(s, LICENCE_TAG_NEW_LICENCE_REQUEST); out_uint8(s, ((g_rdp_version >= RDP_V5) ? 3 : 2)); /* version */ out_uint16_le(s, length); out_uint32_le(s, 1); // KEY_EXCHANGE_ALG_RSA out_uint16(s, 0); out_uint16_le(s, 0xff01); out_uint8p(s, client_random, SEC_RANDOM_SIZE); out_uint16_le(s, 2); out_uint16_le(s, (SEC_MODULUS_SIZE + SEC_PADDING_SIZE)); out_uint8p(s, rsa_data, SEC_MODULUS_SIZE); out_uint8s(s, SEC_PADDING_SIZE); /* Username LICENSE_BINARY_BLOB */ out_uint16_le(s, BB_CLIENT_USER_NAME_BLOB); out_uint16_le(s, userlen); out_uint8p(s, user, userlen); /* Machinename LICENSE_BINARY_BLOB */ out_uint16_le(s, BB_CLIENT_MACHINE_NAME_BLOB); out_uint16_le(s, hostlen); out_uint8p(s, host, hostlen); s_mark_end(s); sec_send(s, sec_flags); } /* Process a licence request packet */ static void licence_process_request(STREAM s) { uint8 null_data[SEC_MODULUS_SIZE]; uint8 *server_random; uint8 signature[LICENCE_SIGNATURE_SIZE]; uint8 hwid[LICENCE_HWID_SIZE]; uint8 *licence_data; int licence_size; void * crypt_key; /* Retrieve the server random from the incoming packet */ in_uint8p(s, server_random, SEC_RANDOM_SIZE); /* We currently use null client keys. This is a bit naughty but, hey, the security of licence negotiation isn't exactly paramount. */ memset(null_data, 0, sizeof(null_data)); licence_generate_keys(null_data, server_random, null_data); licence_size = load_licence(&licence_data); if (licence_size > 0) { /* Generate a signature for the HWID buffer */ licence_generate_hwid(hwid); sec_sign(signature, 16, g_licence_sign_key, 16, hwid, sizeof(hwid)); /* Now encrypt the HWID */ crypt_key = rdssl_rc4_info_create(); rdssl_rc4_set_key(crypt_key, (char *)g_licence_key, 16); rdssl_rc4_crypt(crypt_key, (char *)hwid, (char *)hwid, sizeof(hwid)); rdssl_rc4_info_delete(crypt_key); #if WITH_DEBUG DEBUG(("Sending licensing PDU (message type 0x%02x)\n", LICENCE_TAG_LICENCE_INFO)); #endif licence_info(null_data, null_data, licence_data, licence_size, hwid, signature); xfree(licence_data); return; } #if WITH_DEBUG DEBUG(("Sending licensing PDU (message type 0x%02x)\n", LICENCE_TAG_NEW_LICENCE_REQUEST)); #endif licence_send_new_licence_request(null_data, null_data, g_username, g_hostname); } /* Send a platform challenge response packet */ static void licence_send_platform_challenge_response(uint8 * token, uint8 * crypt_hwid, uint8 * signature) { uint32 sec_flags = SEC_LICENSE_PKT; uint16 length = 58; STREAM s; s = sec_init(sec_flags, length + 2); out_uint8(s, LICENCE_TAG_PLATFORM_CHALLANGE_RESPONSE); out_uint8(s, ((g_rdp_version >= RDP_V5) ? 3 : 2)); /* version */ out_uint16_le(s, length); out_uint16_le(s, 1); out_uint16_le(s, LICENCE_TOKEN_SIZE); out_uint8p(s, token, LICENCE_TOKEN_SIZE); out_uint16_le(s, 1); out_uint16_le(s, LICENCE_HWID_SIZE); out_uint8p(s, crypt_hwid, LICENCE_HWID_SIZE); out_uint8p(s, signature, LICENCE_SIGNATURE_SIZE); s_mark_end(s); sec_send(s, sec_flags); } /* Parse a platform challenge request packet */ static RD_BOOL licence_parse_platform_challenge(STREAM s, uint8 ** token, uint8 ** signature) { uint16 tokenlen; in_uint8s(s, 6); /* unknown: f8 3d 15 00 04 f6 */ in_uint16_le(s, tokenlen); if (tokenlen != LICENCE_TOKEN_SIZE) { error("token len %d\n", tokenlen); return False; } in_uint8p(s, *token, tokenlen); in_uint8p(s, *signature, LICENCE_SIGNATURE_SIZE); return s_check_end(s); } /* Process a platform challenge packet */ static void licence_process_platform_challenge(STREAM s) { uint8 *in_token = NULL, *in_sig; uint8 out_token[LICENCE_TOKEN_SIZE], decrypt_token[LICENCE_TOKEN_SIZE]; uint8 hwid[LICENCE_HWID_SIZE], crypt_hwid[LICENCE_HWID_SIZE]; uint8 sealed_buffer[LICENCE_TOKEN_SIZE + LICENCE_HWID_SIZE]; uint8 out_sig[LICENCE_SIGNATURE_SIZE]; void * crypt_key; /* Parse incoming packet and save the encrypted token */ licence_parse_platform_challenge(s, &in_token, &in_sig); memcpy(out_token, in_token, LICENCE_TOKEN_SIZE); /* Decrypt the token. It should read TEST in Unicode. */ crypt_key = rdssl_rc4_info_create(); rdssl_rc4_set_key(crypt_key, (char *)g_licence_key, 16); rdssl_rc4_crypt(crypt_key, (char *)in_token, (char *)decrypt_token, LICENCE_TOKEN_SIZE); rdssl_rc4_info_delete(crypt_key); /* Generate a signature for a buffer of token and HWID */ licence_generate_hwid(hwid); memcpy(sealed_buffer, decrypt_token, LICENCE_TOKEN_SIZE); memcpy(sealed_buffer + LICENCE_TOKEN_SIZE, hwid, LICENCE_HWID_SIZE); sec_sign(out_sig, 16, g_licence_sign_key, 16, sealed_buffer, sizeof(sealed_buffer)); /* Now encrypt the HWID */ crypt_key = rdssl_rc4_info_create(); rdssl_rc4_set_key(crypt_key, (char *)g_licence_key, 16); rdssl_rc4_crypt(crypt_key, (char *)hwid, (char *)crypt_hwid, LICENCE_HWID_SIZE); licence_send_platform_challenge_response(out_token, crypt_hwid, out_sig); } /* Process a new licence packet */ static void licence_process_new_license(STREAM s) { void * crypt_key; uint32 length; int i; in_uint8s(s, 2); // Skip license binary blob type in_uint16_le(s, length); if (!s_check_rem(s, length)) return; crypt_key = rdssl_rc4_info_create(); rdssl_rc4_set_key(crypt_key, (char *)g_licence_key, 16); rdssl_rc4_crypt(crypt_key, (char *)s->p, (char *)s->p, length); rdssl_rc4_info_delete(crypt_key); /* Parse NEW_LICENSE_INFO block */ in_uint8s(s, 4); // skip dwVersion /* Skip strings, Scope, CompanyName and ProductId to get to the LicenseInfo which we store in license blob. */ length = 0; for (i = 0; i < 4; i++) { in_uint8s(s, length); in_uint32_le(s, length); if (!s_check_rem(s, length)) return; } g_licence_issued = True; save_licence(s->p, length); } /* process a licence error alert packet */ void licence_process_error_alert(STREAM s) { uint32 error_code; uint32 state_transition; uint32 error_info; in_uint32(s, error_code); in_uint32(s, state_transition); in_uint32(s, error_info); /* There is a special case in the error alert handling, when licensing is all good and the server is not sending a license to client, a "Server License Error PDU - Valid Client" packet is sent which means, every thing is ok. Therefor we should flag that everything is ok with license here. */ if (error_code == 0x07) { g_licence_issued = True; return; } /* handle error codes, for now, just report them */ switch (error_code) { case 0x6: // ERR_NO_LICENSE_SERVER warning("License error alert from server: No license server\n"); break; case 0x8: // ERR_INVALID_CLIENT warning("License error alert from server: Invalid client\n"); break; case 0x4: // ERR_INVALID_SCOPE case 0xb: // ERR_INVALID_PRODUCTID case 0xc: // ERR_INVALID_MESSAGE_LENGTH default: warning("License error alert from server: code %u, state transition %u\n", error_code, state_transition); break; } /* handle error codes, for now, just report them */ switch (error_info) { default: break; } g_licence_error_result = True; } /* Process a licence packet */ void licence_process(STREAM s) { uint8 tag; in_uint8(s, tag); in_uint8s(s, 3); /* version, length */ #if WITH_DEBUG DEBUG(("Received licensing PDU (message type 0x%02x)\n", tag)); #endif switch (tag) { case LICENCE_TAG_REQUEST: licence_process_request(s); break; case LICENCE_TAG_PLATFORM_CHALLANGE: licence_process_platform_challenge(s); break; case LICENCE_TAG_NEW_LICENCE: case LICENCE_TAG_UPGRADE_LICENCE: /* we can handle new and upgrades of licences the same way. */ licence_process_new_license(s); break; case LICENCE_TAG_ERROR_ALERT: licence_process_error_alert(s); break; default: unimpl("licence tag 0x%02x\n", tag); } }