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/*
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 2 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, write to the Free Software
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
xrdp: A Remote Desktop Protocol server.
Copyright (C) Jay Sorg 2005-2008
licence
*/
#include "rdp.h"
/*****************************************************************************/
struct rdp_lic* APP_CC
rdp_lic_create(struct rdp_sec* owner)
{
struct rdp_lic* self;
self = (struct rdp_lic*)g_malloc(sizeof(struct rdp_lic), 1);
self->sec_layer = owner;
return self;
}
/*****************************************************************************/
void APP_CC
rdp_lic_delete(struct rdp_lic* self)
{
if (self == 0)
{
return;
}
g_free(self);
}
/*****************************************************************************/
/* Generate a session key and RC4 keys, given client and server randoms */
static void APP_CC
rdp_lic_generate_keys(struct rdp_lic* self, char* client_random,
char* server_random, char* pre_master_secret)
{
char master_secret[48];
char key_block[48];
/* Generate master secret and then key material */
rdp_sec_hash_48(master_secret, pre_master_secret, client_random,
server_random, 65);
rdp_sec_hash_48(key_block, master_secret, server_random,
client_random, 65);
/* Store first 16 bytes of session key as MAC secret */
g_memcpy(self->licence_sign_key, key_block, 16);
/* Generate RC4 key from next 16 bytes */
rdp_sec_hash_16(self->licence_key, key_block + 16, client_random,
server_random);
}
/*****************************************************************************/
static void APP_CC
rdp_lic_generate_hwid(struct rdp_lic* self, char* hwid)
{
rdp_sec_buf_out_uint32(hwid, 2);
g_strncpy(hwid + 4, self->sec_layer->rdp_layer->mod->hostname,
LICENCE_HWID_SIZE - 4);
}
/*****************************************************************************/
/* Present an existing licence to the server */
static void APP_CC
rdp_lic_present(struct rdp_lic* self, char* client_random, char* rsa_data,
char* licence_data, int licence_size, char* hwid,
char* signature)
{
int sec_flags;
int length;
struct stream* s;
sec_flags = SEC_LICENCE_NEG;
length = 16 + SEC_RANDOM_SIZE + SEC_MODULUS_SIZE + SEC_PADDING_SIZE +
licence_size + LICENCE_HWID_SIZE + LICENCE_SIGNATURE_SIZE;
make_stream(s);
init_stream(s, 8192);
rdp_sec_init(self->sec_layer, s, sec_flags);
out_uint8(s, LICENCE_TAG_PRESENT);
out_uint8(s, 2); /* version */
out_uint16_le(s, length);
out_uint32_le(s, 1);
out_uint16_le(s, 0);
out_uint16_le(s, 0x0201);
out_uint8p(s, client_random, SEC_RANDOM_SIZE);
out_uint16_le(s, 0);
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);
rdp_sec_send(self->sec_layer, s, sec_flags);
free_stream(s);
}
/*****************************************************************************/
/* Send a licence request packet */
static void APP_CC
rdp_lic_send_request(struct rdp_lic* self, char* client_random,
char* rsa_data, char* user, char* host)
{
int sec_flags;
int userlen;
int hostlen;
int length;
struct stream* s;
sec_flags = SEC_LICENCE_NEG;
userlen = g_strlen(user) + 1;
hostlen = g_strlen(host) + 1;
length = 128 + userlen + hostlen;
make_stream(s);
init_stream(s, 8192);
rdp_sec_init(self->sec_layer, s, sec_flags);
out_uint8(s, LICENCE_TAG_REQUEST);
out_uint8(s, 2); /* version */
out_uint16_le(s, length);
out_uint32_le(s, 1);
out_uint16_le(s, 0);
out_uint16_le(s, 0xff01);
out_uint8p(s, client_random, SEC_RANDOM_SIZE);
out_uint16_le(s, 0);
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, LICENCE_TAG_USER);
out_uint16_le(s, userlen);
out_uint8p(s, user, userlen);
out_uint16_le(s, LICENCE_TAG_HOST);
out_uint16_le(s, hostlen);
out_uint8p(s, host, hostlen);
s_mark_end(s);
rdp_sec_send(self->sec_layer, s, sec_flags);
free_stream(s);
}
/*****************************************************************************/
/* Process a licence demand packet */
static void APP_CC
rdp_lic_process_demand(struct rdp_lic* self, struct stream* s)
{
char null_data[SEC_MODULUS_SIZE];
char* server_random;
char signature[LICENCE_SIGNATURE_SIZE];
char hwid[LICENCE_HWID_SIZE];
char* licence_data;
int licence_size;
void* crypt_key;
licence_data = 0;
/* 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. */
g_memset(null_data, 0, sizeof(null_data));
rdp_lic_generate_keys(self, null_data, server_random, null_data);
licence_size = 0; /* todo load_licence(&licence_data); */
if (licence_size > 0)
{
/* Generate a signature for the HWID buffer */
rdp_lic_generate_hwid(self, hwid);
rdp_sec_sign(signature, 16, self->licence_sign_key, 16,
hwid, sizeof(hwid));
/* Now encrypt the HWID */
crypt_key = ssl_rc4_info_create();
ssl_rc4_set_key(crypt_key, self->licence_key, 16);
ssl_rc4_crypt(crypt_key, hwid, sizeof(hwid));
ssl_rc4_info_delete(crypt_key);
rdp_lic_present(self, null_data, null_data, licence_data,
licence_size, hwid, signature);
g_free(licence_data);
return;
}
rdp_lic_send_request(self, null_data, null_data,
self->sec_layer->rdp_layer->mod->username,
self->sec_layer->rdp_layer->mod->hostname);
}
/*****************************************************************************/
/* Send an authentication response packet */
static void APP_CC
rdp_lic_send_authresp(struct rdp_lic* self, char* token, char* crypt_hwid,
char* signature)
{
int sec_flags;
int length;
struct stream* s;
sec_flags = SEC_LICENCE_NEG;
length = 58;
make_stream(s);
init_stream(s, 8192);
rdp_sec_init(self->sec_layer, s, sec_flags);
out_uint8(s, LICENCE_TAG_AUTHRESP);
out_uint8(s, 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);
rdp_sec_send(self->sec_layer, s, sec_flags);
free_stream(s);
}
/*****************************************************************************/
/* Parse an authentication request packet */
/* returns boolean */
static int APP_CC
rdp_lic_parse_authreq(struct rdp_lic* self, struct stream* s,
char** token, char** signature)
{
int 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 0;
}
in_uint8p(s, *token, tokenlen);
in_uint8p(s, *signature, LICENCE_SIGNATURE_SIZE);
return s_check_end(s);
}
/*****************************************************************************/
/* Process an authentication request packet */
static void APP_CC
rdp_lic_process_authreq(struct rdp_lic* self, struct stream* s)
{
char* in_token;
char* in_sig;
char out_token[LICENCE_TOKEN_SIZE];
char decrypt_token[LICENCE_TOKEN_SIZE];
char hwid[LICENCE_HWID_SIZE];
char crypt_hwid[LICENCE_HWID_SIZE];
char sealed_buffer[LICENCE_TOKEN_SIZE + LICENCE_HWID_SIZE];
char out_sig[LICENCE_SIGNATURE_SIZE];
void* crypt_key;
in_token = 0;
in_sig = 0;
/* Parse incoming packet and save the encrypted token */
rdp_lic_parse_authreq(self, s, &in_token, &in_sig);
g_memcpy(out_token, in_token, LICENCE_TOKEN_SIZE);
/* Decrypt the token. It should read TEST in Unicode. */
crypt_key = ssl_rc4_info_create();
ssl_rc4_set_key(crypt_key, self->licence_key, 16);
g_memcpy(decrypt_token, in_token, LICENCE_TOKEN_SIZE);
ssl_rc4_crypt(crypt_key, decrypt_token, LICENCE_TOKEN_SIZE);
/* Generate a signature for a buffer of token and HWID */
rdp_lic_generate_hwid(self, hwid);
g_memcpy(sealed_buffer, decrypt_token, LICENCE_TOKEN_SIZE);
g_memcpy(sealed_buffer + LICENCE_TOKEN_SIZE, hwid, LICENCE_HWID_SIZE);
rdp_sec_sign(out_sig, 16, self->licence_sign_key, 16, sealed_buffer,
sizeof(sealed_buffer));
/* Now encrypt the HWID */
ssl_rc4_set_key(crypt_key, self->licence_key, 16);
g_memcpy(crypt_hwid, hwid, LICENCE_HWID_SIZE);
ssl_rc4_crypt(crypt_key, crypt_hwid, LICENCE_HWID_SIZE);
rdp_lic_send_authresp(self, out_token, crypt_hwid, out_sig);
ssl_rc4_info_delete(crypt_key);
}
/*****************************************************************************/
/* Process an licence issue packet */
static void APP_CC
rdp_lic_process_issue(struct rdp_lic* self, struct stream* s)
{
void* crypt_key;
int length;
int check;
int i;
in_uint8s(s, 2); /* 3d 45 - unknown */
in_uint16_le(s, length);
if (!s_check_rem(s, length))
{
return;
}
crypt_key = ssl_rc4_info_create();
ssl_rc4_set_key(crypt_key, self->licence_key, 16);
ssl_rc4_crypt(crypt_key, s->p, length);
ssl_rc4_info_delete(crypt_key);
in_uint16_le(s, check);
if (check != 0)
{
return;
}
self->licence_issued = 1;
in_uint8s(s, 2); /* pad */
/* advance to fourth string */
length = 0;
for (i = 0; i < 4; i++)
{
in_uint8s(s, length);
in_uint32_le(s, length);
if (!s_check_rem(s, length))
{
return;
}
}
/* todo save_licence(s->p, length); */
}
/******************************************************************************/
/* Process a licence packet */
void APP_CC
rdp_lic_process(struct rdp_lic* self, struct stream* s)
{
int tag;
in_uint8(s, tag);
in_uint8s(s, 3); /* version, length */
switch (tag)
{
case LICENCE_TAG_DEMAND:
rdp_lic_process_demand(self, s);
break;
case LICENCE_TAG_AUTHREQ:
rdp_lic_process_authreq(self, s);
break;
case LICENCE_TAG_ISSUE:
rdp_lic_process_issue(self, s);
break;
case LICENCE_TAG_REISSUE:
case LICENCE_TAG_RESULT:
break;
default:
break;
/* todo unimpl("licence tag 0x%x\n", tag); */
}
}
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