--- /dev/null
+/* -*- c-basic-offset: 8 -*-
+ rdesktop: A Remote Desktop Protocol client.
+ Protocol services - Virtual channels
+ Copyright (C) Erik Forsberg <forsberg@cendio.se> 2003
+ Copyright (C) Matthew Chapman 2003
+
+ 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.
+*/
+
+#include "rdesktop.h"
+
+#define MAX_CHANNELS 4
+#define CHANNEL_CHUNK_LENGTH 1600
+#define CHANNEL_FLAG_FIRST 0x01
+#define CHANNEL_FLAG_LAST 0x02
+#define CHANNEL_FLAG_SHOW_PROTOCOL 0x10
+
+extern BOOL g_use_rdp5;
+extern BOOL g_encryption;
+
+VCHANNEL g_channels[MAX_CHANNELS];
+unsigned int g_num_channels;
+
+/* FIXME: We should use the information in TAG_SRV_CHANNELS to map RDP5
+ channels to MCS channels.
+
+ The format of TAG_SRV_CHANNELS seems to be
+
+ global_channel_no (uint16le)
+ number_of_other_channels (uint16le)
+ ..followed by uint16les for the other channels.
+*/
+
+VCHANNEL *
+channel_register(char *name, uint32 flags, void (*callback) (STREAM))
+{
+ VCHANNEL *channel;
+
+ if (g_num_channels >= MAX_CHANNELS)
+ {
+ error("Channel table full, increase MAX_CHANNELS\n");
+ return NULL;
+ }
+
+ channel = &g_channels[g_num_channels];
+ channel->mcs_id = MCS_GLOBAL_CHANNEL + 1 + g_num_channels;
+ strncpy(channel->name, name, 8);
+ channel->flags = flags;
+ channel->process = callback;
+ g_num_channels++;
+ return channel;
+}
+
+STREAM
+channel_init(VCHANNEL * channel, uint32 length)
+{
+ STREAM s;
+
+ s = sec_init(/*g_encryption ? SEC_ENCRYPT :*/ 0, length + 8);
+ s_push_layer(s, channel_hdr, 8);
+ return s;
+}
+
+void
+channel_send(STREAM s, VCHANNEL * channel)
+{
+ uint32 length, flags;
+ uint32 thislength, remaining;
+ uint8 *data;
+
+ /* first fragment sent in-place */
+ s_pop_layer(s, channel_hdr);
+ length = s->end - s->p - 8;
+
+ DEBUG_CLIPBOARD(("channel_send, length = %d\n", length));
+
+ thislength = MIN(length, CHANNEL_CHUNK_LENGTH);
+/* Note: In the original clipboard implementation, this number was
+ 1592, not 1600. However, I don't remember the reason and 1600 seems
+ to work so.. This applies only to *this* length, not the length of
+ continuation or ending packets. */
+ remaining = length - thislength;
+ flags = (remaining == 0) ? CHANNEL_FLAG_FIRST | CHANNEL_FLAG_LAST : CHANNEL_FLAG_FIRST;
+ if (channel->flags & CHANNEL_OPTION_SHOW_PROTOCOL)
+ flags |= CHANNEL_FLAG_SHOW_PROTOCOL;
+
+ out_uint32_le(s, length);
+ out_uint32_le(s, flags);
+ data = s->end = s->p + thislength;
+ DEBUG_CLIPBOARD(("Sending %d bytes with FLAG_FIRST\n", thislength));
+ sec_send_to_channel(s, /*g_encryption ? SEC_ENCRYPT :*/ 0, channel->mcs_id);
+
+ /* subsequent segments copied (otherwise would have to generate headers backwards) */
+ while (remaining > 0)
+ {
+ thislength = MIN(remaining, CHANNEL_CHUNK_LENGTH);
+ remaining -= thislength;
+ flags = (remaining == 0) ? CHANNEL_FLAG_LAST : 0;
+ if (channel->flags & CHANNEL_OPTION_SHOW_PROTOCOL)
+ flags |= CHANNEL_FLAG_SHOW_PROTOCOL;
+
+ DEBUG_CLIPBOARD(("Sending %d bytes with flags %d\n", thislength, flags));
+
+ s = sec_init(/*g_encryption ? SEC_ENCRYPT : */0, thislength + 8);
+ out_uint32_le(s, length);
+ out_uint32_le(s, flags);
+ out_uint8p(s, data, thislength);
+ s_mark_end(s);
+ sec_send_to_channel(s, /*g_encryption ? SEC_ENCRYPT : */0, channel->mcs_id);
+
+ data += thislength;
+ }
+}
+
+void
+channel_process(STREAM s, uint16 mcs_channel)
+{
+ uint32 length, flags;
+ uint32 thislength;
+ VCHANNEL *channel = NULL;
+ unsigned int i;
+ STREAM in;
+
+ for (i = 0; i < g_num_channels; i++)
+ {
+ channel = &g_channels[i];
+ if (channel->mcs_id == mcs_channel)
+ break;
+ }
+
+ if (i >= g_num_channels)
+ return;
+
+ in_uint32_le(s, length);
+ in_uint32_le(s, flags);
+ if ((flags & CHANNEL_FLAG_FIRST) && (flags & CHANNEL_FLAG_LAST))
+ {
+ /* single fragment - pass straight up */
+ channel->process(s);
+ }
+ else
+ {
+ /* add fragment to defragmentation buffer */
+ in = &channel->in;
+ if (flags & CHANNEL_FLAG_FIRST)
+ {
+ if (length > in->size)
+ {
+ in->data = xrealloc(in->data, length);
+ in->size = length;
+ }
+ in->p = in->data;
+ }
+
+ thislength = MIN(s->end - s->p, in->data + in->size - in->p);
+ memcpy(in->p, s->p, thislength);
+ in->p += thislength;
+
+ if (flags & CHANNEL_FLAG_LAST)
+ {
+ in->end = in->p;
+ in->p = in->data;
+ channel->process(in);
+ }
+ }
+}
--- /dev/null
+/* -*- c-basic-offset: 8 -*-
+ rdesktop: A Remote Desktop Protocol client.
+ Protocol services - Multipoint Communications Service
+ Copyright (C) Matthew Chapman 1999-2002
+
+ 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.
+*/
+
+#include "rdesktop.h"
+
+uint16 g_mcs_userid;
+extern VCHANNEL g_channels[];
+extern unsigned int g_num_channels;
+
+/* Parse an ASN.1 BER header */
+static BOOL
+ber_parse_header(STREAM s, int tagval, int *length)
+{
+ int tag, len;
+
+ if (tagval > 0xff)
+ {
+ in_uint16_be(s, tag);
+ }
+ else
+ {
+ in_uint8(s, tag)}
+
+ if (tag != tagval)
+ {
+ error("expected tag %d, got %d\n", tagval, tag);
+ return False;
+ }
+
+ in_uint8(s, len);
+
+ if (len & 0x80)
+ {
+ len &= ~0x80;
+ *length = 0;
+ while (len--)
+ next_be(s, *length);
+ }
+ else
+ *length = len;
+
+ return s_check(s);
+}
+
+/* Output an ASN.1 BER header */
+static void
+ber_out_header(STREAM s, int tagval, int length)
+{
+ if (tagval > 0xff)
+ {
+ out_uint16_be(s, tagval);
+ }
+ else
+ {
+ out_uint8(s, tagval);
+ }
+
+ if (length >= 0x80)
+ {
+ out_uint8(s, 0x82);
+ out_uint16_be(s, length);
+ }
+ else
+ out_uint8(s, length);
+}
+
+/* Output an ASN.1 BER integer */
+static void
+ber_out_integer(STREAM s, int value)
+{
+ ber_out_header(s, BER_TAG_INTEGER, 2);
+ out_uint16_be(s, value);
+}
+
+/* Output a DOMAIN_PARAMS structure (ASN.1 BER) */
+static void
+mcs_out_domain_params(STREAM s, int max_channels, int max_users, int max_tokens, int max_pdusize)
+{
+ ber_out_header(s, MCS_TAG_DOMAIN_PARAMS, 32);
+ ber_out_integer(s, max_channels);
+ ber_out_integer(s, max_users);
+ ber_out_integer(s, max_tokens);
+ ber_out_integer(s, 1); /* num_priorities */
+ ber_out_integer(s, 0); /* min_throughput */
+ ber_out_integer(s, 1); /* max_height */
+ ber_out_integer(s, max_pdusize);
+ ber_out_integer(s, 2); /* ver_protocol */
+}
+
+/* Parse a DOMAIN_PARAMS structure (ASN.1 BER) */
+static BOOL
+mcs_parse_domain_params(STREAM s)
+{
+ int length;
+
+ ber_parse_header(s, MCS_TAG_DOMAIN_PARAMS, &length);
+ in_uint8s(s, length);
+
+ return s_check(s);
+}
+
+/* Send an MCS_CONNECT_INITIAL message (ASN.1 BER) */
+static void
+mcs_send_connect_initial(STREAM mcs_data)
+{
+ int datalen = mcs_data->end - mcs_data->data;
+ int length = 9 + 3 * 34 + 4 + datalen;
+ STREAM s;
+
+ s = iso_init(length + 5);
+
+ ber_out_header(s, MCS_CONNECT_INITIAL, length);
+ ber_out_header(s, BER_TAG_OCTET_STRING, 1); /* calling domain */
+ out_uint8(s, 1);
+ ber_out_header(s, BER_TAG_OCTET_STRING, 1); /* called domain */
+ out_uint8(s, 1);
+
+ ber_out_header(s, BER_TAG_BOOLEAN, 1);
+ out_uint8(s, 0xff); /* upward flag */
+
+ mcs_out_domain_params(s, 34, 2, 0, 0xffff); /* target params */
+ mcs_out_domain_params(s, 1, 1, 1, 0x420); /* min params */
+ mcs_out_domain_params(s, 0xffff, 0xfc17, 0xffff, 0xffff); /* max params */
+
+ ber_out_header(s, BER_TAG_OCTET_STRING, datalen);
+ out_uint8p(s, mcs_data->data, datalen);
+
+ s_mark_end(s);
+ iso_send(s);
+}
+
+/* Expect a MCS_CONNECT_RESPONSE message (ASN.1 BER) */
+static BOOL
+mcs_recv_connect_response(STREAM mcs_data)
+{
+ uint8 result;
+ int length;
+ STREAM s;
+
+ s = iso_recv();
+ if (s == NULL)
+ return False;
+
+ ber_parse_header(s, MCS_CONNECT_RESPONSE, &length);
+
+ ber_parse_header(s, BER_TAG_RESULT, &length);
+ in_uint8(s, result);
+ if (result != 0)
+ {
+ error("MCS connect: %d\n", result);
+ return False;
+ }
+
+ ber_parse_header(s, BER_TAG_INTEGER, &length);
+ in_uint8s(s, length); /* connect id */
+ mcs_parse_domain_params(s);
+
+ ber_parse_header(s, BER_TAG_OCTET_STRING, &length);
+
+ sec_process_mcs_data(s);
+ /*
+ if (length > mcs_data->size)
+ {
+ error("MCS data length %d, expected %d\n", length,
+ mcs_data->size);
+ length = mcs_data->size;
+ }
+
+ in_uint8a(s, mcs_data->data, length);
+ mcs_data->p = mcs_data->data;
+ mcs_data->end = mcs_data->data + length;
+ */
+ return s_check_end(s);
+}
+
+/* Send an EDrq message (ASN.1 PER) */
+static void
+mcs_send_edrq(void)
+{
+ STREAM s;
+
+ s = iso_init(5);
+
+ out_uint8(s, (MCS_EDRQ << 2));
+ out_uint16_be(s, 1); /* height */
+ out_uint16_be(s, 1); /* interval */
+
+ s_mark_end(s);
+ iso_send(s);
+}
+
+/* Send an AUrq message (ASN.1 PER) */
+static void
+mcs_send_aurq(void)
+{
+ STREAM s;
+
+ s = iso_init(1);
+
+ out_uint8(s, (MCS_AURQ << 2));
+
+ s_mark_end(s);
+ iso_send(s);
+}
+
+/* Expect a AUcf message (ASN.1 PER) */
+static BOOL
+mcs_recv_aucf(uint16 * mcs_userid)
+{
+ uint8 opcode, result;
+ STREAM s;
+
+ s = iso_recv();
+ if (s == NULL)
+ return False;
+
+ in_uint8(s, opcode);
+ if ((opcode >> 2) != MCS_AUCF)
+ {
+ error("expected AUcf, got %d\n", opcode);
+ return False;
+ }
+
+ in_uint8(s, result);
+ if (result != 0)
+ {
+ error("AUrq: %d\n", result);
+ return False;
+ }
+
+ if (opcode & 2)
+ in_uint16_be(s, *mcs_userid);
+
+ return s_check_end(s);
+}
+
+/* Send a CJrq message (ASN.1 PER) */
+static void
+mcs_send_cjrq(uint16 chanid)
+{
+ STREAM s;
+
+ DEBUG_RDP5(("Sending CJRQ for channel #%d\n", chanid));
+
+ s = iso_init(5);
+
+ out_uint8(s, (MCS_CJRQ << 2));
+ out_uint16_be(s, g_mcs_userid);
+ out_uint16_be(s, chanid);
+
+ s_mark_end(s);
+ iso_send(s);
+}
+
+/* Expect a CJcf message (ASN.1 PER) */
+static BOOL
+mcs_recv_cjcf(void)
+{
+ uint8 opcode, result;
+ STREAM s;
+
+ s = iso_recv();
+ if (s == NULL)
+ return False;
+
+ in_uint8(s, opcode);
+ if ((opcode >> 2) != MCS_CJCF)
+ {
+ error("expected CJcf, got %d\n", opcode);
+ return False;
+ }
+
+ in_uint8(s, result);
+ if (result != 0)
+ {
+ error("CJrq: %d\n", result);
+ return False;
+ }
+
+ in_uint8s(s, 4); /* mcs_userid, req_chanid */
+ if (opcode & 2)
+ in_uint8s(s, 2); /* join_chanid */
+
+ return s_check_end(s);
+}
+
+/* Initialise an MCS transport data packet */
+STREAM
+mcs_init(int length)
+{
+ STREAM s;
+
+ s = iso_init(length + 8);
+ s_push_layer(s, mcs_hdr, 8);
+
+ return s;
+}
+
+/* Send an MCS transport data packet to a specific channel */
+void
+mcs_send_to_channel(STREAM s, uint16 channel)
+{
+ uint16 length;
+
+ s_pop_layer(s, mcs_hdr);
+ length = s->end - s->p - 8;
+ length |= 0x8000;
+
+ out_uint8(s, (MCS_SDRQ << 2));
+ out_uint16_be(s, g_mcs_userid);
+ out_uint16_be(s, channel);
+ out_uint8(s, 0x70); /* flags */
+ out_uint16_be(s, length);
+
+ iso_send(s);
+}
+
+/* Send an MCS transport data packet to the global channel */
+void
+mcs_send(STREAM s)
+{
+ mcs_send_to_channel(s, MCS_GLOBAL_CHANNEL);
+}
+
+/* Receive an MCS transport data packet */
+STREAM
+mcs_recv(uint16 * channel)
+{
+ uint8 opcode, appid, length;
+ STREAM s;
+
+ s = iso_recv();
+ if (s == NULL)
+ return NULL;
+
+ in_uint8(s, opcode);
+ appid = opcode >> 2;
+ if (appid != MCS_SDIN)
+ {
+ if (appid != MCS_DPUM)
+ {
+ error("expected data, got %d\n", opcode);
+ }
+ return NULL;
+ }
+
+ in_uint8s(s, 2); /* userid */
+ in_uint16_be(s, *channel);
+ in_uint8s(s, 1); /* flags */
+ in_uint8(s, length);
+ if (length & 0x80)
+ in_uint8s(s, 1); /* second byte of length */
+
+ return s;
+}
+
+/* Disconnect from the MCS layer */
+void
+mcs_disconnect(void)
+{
+ iso_disconnect();
+}
--- /dev/null
+/* -*- c-basic-offset: 8 -*-
+ rdesktop: A Remote Desktop Protocol client.
+ Protocol services - RDP encryption and licensing
+ Copyright (C) Matthew Chapman 1999-2002
+
+ 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.
+*/
+
+#include "rdesktop.h"
+
+#include <openssl/rc4.h>
+#include <openssl/md5.h>
+#include <openssl/sha.h>
+#include <openssl/bn.h>
+#include <openssl/x509v3.h>
+
+extern char hostname[16];
+extern int g_width;
+extern int g_height;
+extern int keylayout;
+extern BOOL g_encryption;
+extern BOOL g_licence_issued;
+extern BOOL g_use_rdp5;
+extern BOOL g_console_session;
+extern int g_server_bpp;
+extern uint16 mcs_userid;
+extern VCHANNEL g_channels[];
+extern unsigned int g_num_channels;
+
+static int rc4_key_len;
+static RC4_KEY rc4_decrypt_key;
+static RC4_KEY rc4_encrypt_key;
+static RSA *server_public_key;
+
+static uint8 sec_sign_key[16];
+static uint8 sec_decrypt_key[16];
+static uint8 sec_encrypt_key[16];
+static uint8 sec_decrypt_update_key[16];
+static uint8 sec_encrypt_update_key[16];
+static uint8 sec_crypted_random[SEC_MODULUS_SIZE];
+
+uint16 g_server_rdp_version = 0;
+
+/*
+ * General purpose 48-byte transformation, using two 32-byte salts (generally,
+ * a client and server salt) and a global salt value used for padding.
+ * Both SHA1 and MD5 algorithms are used.
+ */
+void
+sec_hash_48(uint8 * out, uint8 * in, uint8 * salt1, uint8 * salt2, uint8 salt)
+{
+ uint8 shasig[20];
+ uint8 pad[4];
+ SHA_CTX sha;
+ MD5_CTX md5;
+ int i;
+
+ for (i = 0; i < 3; i++)
+ {
+ memset(pad, salt + i, i + 1);
+
+ SHA1_Init(&sha);
+ SHA1_Update(&sha, pad, i + 1);
+ SHA1_Update(&sha, in, 48);
+ SHA1_Update(&sha, salt1, 32);
+ SHA1_Update(&sha, salt2, 32);
+ SHA1_Final(shasig, &sha);
+
+ MD5_Init(&md5);
+ MD5_Update(&md5, in, 48);
+ MD5_Update(&md5, shasig, 20);
+ MD5_Final(&out[i * 16], &md5);
+ }
+}
+
+/*
+ * Weaker 16-byte transformation, also using two 32-byte salts, but
+ * only using a single round of MD5.
+ */
+void
+sec_hash_16(uint8 * out, uint8 * in, uint8 * salt1, uint8 * salt2)
+{
+ MD5_CTX md5;
+
+ MD5_Init(&md5);
+ MD5_Update(&md5, in, 16);
+ MD5_Update(&md5, salt1, 32);
+ MD5_Update(&md5, salt2, 32);
+ MD5_Final(out, &md5);
+}
+
+/* Reduce key entropy from 64 to 40 bits */
+static void
+sec_make_40bit(uint8 * key)
+{
+ key[0] = 0xd1;
+ key[1] = 0x26;
+ key[2] = 0x9e;
+}
+
+/* Generate a session key and RC4 keys, given client and server randoms */
+static void
+sec_generate_keys(uint8 * client_key, uint8 * server_key, int rc4_key_size)
+{
+ uint8 session_key[48];
+ uint8 temp_hash[48];
+ uint8 input[48];
+
+ /* Construct input data to hash */
+ memcpy(input, client_key, 24);
+ memcpy(input + 24, server_key, 24);
+
+ /* Generate session key - two rounds of sec_hash_48 */
+ sec_hash_48(temp_hash, input, client_key, server_key, 65);
+ sec_hash_48(session_key, temp_hash, client_key, server_key, 88);
+
+ /* Store first 16 bytes of session key, for generating signatures */
+ memcpy(sec_sign_key, session_key, 16);
+
+ /* Generate RC4 keys */
+ sec_hash_16(sec_decrypt_key, &session_key[16], client_key, server_key);
+ sec_hash_16(sec_encrypt_key, &session_key[32], client_key, server_key);
+
+ if (rc4_key_size == 1)
+ {
+ DEBUG(("40-bit encryption enabled\n"));
+ sec_make_40bit(sec_sign_key);
+ sec_make_40bit(sec_decrypt_key);
+ sec_make_40bit(sec_encrypt_key);
+ rc4_key_len = 8;
+ }
+ else
+ {
+ DEBUG(("rc_4_key_size == %d, 128-bit encryption enabled\n", rc4_key_size));
+ rc4_key_len = 16;
+ }
+
+ /* Save initial RC4 keys as update keys */
+ memcpy(sec_decrypt_update_key, sec_decrypt_key, 16);
+ memcpy(sec_encrypt_update_key, sec_encrypt_key, 16);
+
+ /* Initialise RC4 state arrays */
+ RC4_set_key(&rc4_decrypt_key, rc4_key_len, sec_decrypt_key);
+ RC4_set_key(&rc4_encrypt_key, rc4_key_len, sec_encrypt_key);
+}
+
+static uint8 pad_54[40] = {
+ 54, 54, 54, 54, 54, 54, 54, 54, 54, 54, 54, 54, 54, 54, 54, 54, 54,
+ 54, 54, 54,
+ 54, 54, 54, 54, 54, 54, 54, 54, 54, 54, 54, 54, 54, 54, 54, 54, 54,
+ 54, 54, 54
+};
+
+static uint8 pad_92[48] = {
+ 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92,
+ 92, 92, 92, 92, 92, 92, 92,
+ 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92,
+ 92, 92, 92, 92, 92, 92, 92
+};
+
+/* Output a uint32 into a buffer (little-endian) */
+void
+buf_out_uint32(uint8 * buffer, uint32 value)
+{
+ buffer[0] = (value) & 0xff;
+ buffer[1] = (value >> 8) & 0xff;
+ buffer[2] = (value >> 16) & 0xff;
+ buffer[3] = (value >> 24) & 0xff;
+}
+
+/* Generate a signature hash, using a combination of SHA1 and MD5 */
+void
+sec_sign(uint8 * signature, int siglen, uint8 * session_key, int keylen, uint8 * data, int datalen)
+{
+ uint8 shasig[20];
+ uint8 md5sig[16];
+ uint8 lenhdr[4];
+ SHA_CTX sha;
+ MD5_CTX md5;
+
+ buf_out_uint32(lenhdr, datalen);
+
+ SHA1_Init(&sha);
+ SHA1_Update(&sha, session_key, keylen);
+ SHA1_Update(&sha, pad_54, 40);
+ SHA1_Update(&sha, lenhdr, 4);
+ SHA1_Update(&sha, data, datalen);
+ SHA1_Final(shasig, &sha);
+
+ MD5_Init(&md5);
+ MD5_Update(&md5, session_key, keylen);
+ MD5_Update(&md5, pad_92, 48);
+ MD5_Update(&md5, shasig, 20);
+ MD5_Final(md5sig, &md5);
+
+ memcpy(signature, md5sig, siglen);
+}
+
+/* Update an encryption key - similar to the signing process */
+static void
+sec_update(uint8 * key, uint8 * update_key)
+{
+ uint8 shasig[20];
+ SHA_CTX sha;
+ MD5_CTX md5;
+ RC4_KEY update;
+
+ SHA1_Init(&sha);
+ SHA1_Update(&sha, update_key, rc4_key_len);
+ SHA1_Update(&sha, pad_54, 40);
+ SHA1_Update(&sha, key, rc4_key_len);
+ SHA1_Final(shasig, &sha);
+
+ MD5_Init(&md5);
+ MD5_Update(&md5, update_key, rc4_key_len);
+ MD5_Update(&md5, pad_92, 48);
+ MD5_Update(&md5, shasig, 20);
+ MD5_Final(key, &md5);
+
+ RC4_set_key(&update, rc4_key_len, key);
+ RC4(&update, rc4_key_len, key, key);
+
+ if (rc4_key_len == 8)
+ sec_make_40bit(key);
+}
+
+/* Encrypt data using RC4 */
+static void
+sec_encrypt(uint8 * data, int length)
+{
+ static int use_count;
+
+ if (use_count == 4096)
+ {
+ sec_update(sec_encrypt_key, sec_encrypt_update_key);
+ RC4_set_key(&rc4_encrypt_key, rc4_key_len, sec_encrypt_key);
+ use_count = 0;
+ }
+
+ RC4(&rc4_encrypt_key, length, data, data);
+ use_count++;
+}
+
+/* Decrypt data using RC4 */
+void
+sec_decrypt(uint8 * data, int length)
+{
+ static int use_count;
+
+ if (use_count == 4096)
+ {
+ sec_update(sec_decrypt_key, sec_decrypt_update_key);
+ RC4_set_key(&rc4_decrypt_key, rc4_key_len, sec_decrypt_key);
+ use_count = 0;
+ }
+
+ RC4(&rc4_decrypt_key, length, data, data);
+ use_count++;
+}
+
+static void
+reverse(uint8 * p, int len)
+{
+ int i, j;
+ uint8 temp;
+
+ for (i = 0, j = len - 1; i < j; i++, j--)
+ {
+ temp = p[i];
+ p[i] = p[j];
+ p[j] = temp;
+ }
+}
+
+/* Perform an RSA public key encryption operation */
+static void
+sec_rsa_encrypt(uint8 * out, uint8 * in, int len, uint8 * modulus, uint8 * exponent)
+{
+ BN_CTX *ctx;
+ BIGNUM mod, exp, x, y;
+ uint8 inr[SEC_MODULUS_SIZE];
+ int outlen;
+
+ reverse(modulus, SEC_MODULUS_SIZE);
+ reverse(exponent, SEC_EXPONENT_SIZE);
+ memcpy(inr, in, len);
+ reverse(inr, len);
+
+ ctx = BN_CTX_new();
+ BN_init(&mod);
+ BN_init(&exp);
+ BN_init(&x);
+ BN_init(&y);
+
+ BN_bin2bn(modulus, SEC_MODULUS_SIZE, &mod);
+ BN_bin2bn(exponent, SEC_EXPONENT_SIZE, &exp);
+ BN_bin2bn(inr, len, &x);
+ BN_mod_exp(&y, &x, &exp, &mod, ctx);
+ outlen = BN_bn2bin(&y, out);
+ reverse(out, outlen);
+ if (outlen < SEC_MODULUS_SIZE)
+ memset(out + outlen, 0, SEC_MODULUS_SIZE - outlen);
+
+ BN_free(&y);
+ BN_clear_free(&x);
+ BN_free(&exp);
+ BN_free(&mod);
+ BN_CTX_free(ctx);
+}
+
+/* Initialise secure transport packet */
+STREAM
+sec_init(uint32 flags, int maxlen)
+{
+ int hdrlen;
+ STREAM s;
+
+ /*if (!g_licence_issued) */
+ hdrlen = (flags & SEC_ENCRYPT) ? 12 : 4;
+/* else
+ hdrlen = (flags & SEC_ENCRYPT) ? 12 : 0; */
+ s = mcs_init(maxlen + hdrlen);
+ s_push_layer(s, sec_hdr, hdrlen);
+
+ return s;
+}
+
+/* Transmit secure transport packet over specified channel */
+void
+sec_send_to_channel(STREAM s, uint32 flags, uint16 channel)
+{
+ int datalen;
+
+ s_pop_layer(s, sec_hdr);
+ //if (!g_licence_issued || (flags & SEC_ENCRYPT))
+ out_uint32_le(s, flags);
+
+ if (flags & SEC_ENCRYPT)
+ {
+ flags &= ~SEC_ENCRYPT;
+ datalen = s->end - s->p - 8;
+
+#if WITH_DEBUG
+ DEBUG(("Sending encrypted packet:\n"));
+ hexdump(s->p + 8, datalen);
+#endif
+
+ sec_sign(s->p, 8, sec_sign_key, rc4_key_len, s->p + 8, datalen);
+ sec_encrypt(s->p + 8, datalen);
+ }
+
+ mcs_send_to_channel(s, channel);
+}
+
+/* Transmit secure transport packet */
+
+void
+sec_send(STREAM s, uint32 flags)
+{
+ sec_send_to_channel(s, flags, MCS_GLOBAL_CHANNEL);
+}
+
+
+/* Transfer the client random to the server */
+static void
+sec_establish_key(void)
+{
+ uint32 length = SEC_MODULUS_SIZE + SEC_PADDING_SIZE;
+ uint32 flags = SEC_CLIENT_RANDOM;
+ STREAM s;
+
+ s = sec_init(flags, 76);
+
+ out_uint32_le(s, length);
+ out_uint8p(s, sec_crypted_random, SEC_MODULUS_SIZE);
+ out_uint8s(s, SEC_PADDING_SIZE);
+
+ s_mark_end(s);
+ sec_send(s, flags);
+}
+
+/* Parse a public key structure */
+static BOOL
+sec_parse_public_key(STREAM s, uint8 ** modulus, uint8 ** exponent)
+{
+ uint32 magic, modulus_len;
+
+ in_uint32_le(s, magic);
+ if (magic != SEC_RSA_MAGIC)
+ {
+ error("RSA magic 0x%x\n", magic);
+ return False;
+ }
+
+ in_uint32_le(s, modulus_len);
+ if (modulus_len != SEC_MODULUS_SIZE + SEC_PADDING_SIZE)
+ {
+ error("modulus len 0x%x\n", modulus_len);
+ return False;
+ }
+
+ in_uint8s(s, 8); /* modulus_bits, unknown */
+ in_uint8p(s, *exponent, SEC_EXPONENT_SIZE);
+ in_uint8p(s, *modulus, SEC_MODULUS_SIZE);
+ in_uint8s(s, SEC_PADDING_SIZE);
+
+ return s_check(s);
+}
+
+static BOOL
+sec_parse_x509_key(X509 * cert)
+{
+ EVP_PKEY *epk = NULL;
+ /* By some reason, Microsoft sets the OID of the Public RSA key to
+ the oid for "MD5 with RSA Encryption" instead of "RSA Encryption"
+
+ Kudos to Richard Levitte for the following (. intiutive .)
+ lines of code that resets the OID and let's us extract the key. */
+ if (OBJ_obj2nid(cert->cert_info->key->algor->algorithm) == NID_md5WithRSAEncryption)
+ {
+ DEBUG_RDP5(("Re-setting algorithm type to RSA in server certificate\n"));
+ cert->cert_info->key->algor->algorithm = OBJ_nid2obj(NID_rsaEncryption);
+ }
+ epk = X509_get_pubkey(cert);
+ if (NULL == epk)
+ {
+ error("Failed to extract public key from certificate\n");
+ return False;
+ }
+
+ server_public_key = (RSA *) epk->pkey.ptr;
+
+ return True;
+}
+
+
+/* Parse a crypto information structure */
+static BOOL
+sec_parse_crypt_info(STREAM s, uint32 * rc4_key_size,
+ uint8 ** server_random, uint8 ** modulus, uint8 ** exponent)
+{
+ uint32 crypt_level, random_len, rsa_info_len;
+ uint32 cacert_len, cert_len, flags;
+ X509 *cacert, *server_cert;
+ uint16 tag, length;
+ uint8 *next_tag, *end;
+
+ in_uint32_le(s, *rc4_key_size); /* 1 = 40-bit, 2 = 128-bit */
+ in_uint32_le(s, crypt_level); /* 1 = low, 2 = medium, 3 = high */
+ if (crypt_level == 0) /* no encryption */
+ return False;
+ in_uint32_le(s, random_len);
+ in_uint32_le(s, rsa_info_len);
+
+ if (random_len != SEC_RANDOM_SIZE)
+ {
+ error("random len %d, expected %d\n", random_len, SEC_RANDOM_SIZE);
+ return False;
+ }
+
+ in_uint8p(s, *server_random, random_len);
+
+ /* RSA info */
+ end = s->p + rsa_info_len;
+ if (end > s->end)
+ return False;
+
+ in_uint32_le(s, flags); /* 1 = RDP4-style, 0x80000002 = X.509 */
+ if (flags & 1)
+ {
+ DEBUG_RDP5(("We're going for the RDP4-style encryption\n"));
+ in_uint8s(s, 8); /* unknown */
+
+ while (s->p < end)
+ {
+ in_uint16_le(s, tag);
+ in_uint16_le(s, length);
+
+ next_tag = s->p + length;
+
+ switch (tag)
+ {
+ case SEC_TAG_PUBKEY:
+ if (!sec_parse_public_key(s, modulus, exponent))
+ return False;
+ DEBUG_RDP5(("Got Public key, RDP4-style\n"));
+
+ break;
+
+ case SEC_TAG_KEYSIG:
+ /* Is this a Microsoft key that we just got? */
+ /* Care factor: zero! */
+ /* Actually, it would probably be a good idea to check if the public key is signed with this key, and then store this
+ key as a known key of the hostname. This would prevent some MITM-attacks. */
+ break;
+
+ default:
+ unimpl("crypt tag 0x%x\n", tag);
+ }
+
+ s->p = next_tag;
+ }
+ }
+ else
+ {
+ uint32 certcount;
+
+ DEBUG_RDP5(("We're going for the RDP5-style encryption\n"));
+ in_uint32_le(s, certcount); /* Number of certificates */
+
+ if(certcount < 2)
+ {
+ error("Server didn't send enough X509 certificates\n");
+ return False;
+ }
+
+ for(; certcount > 2; certcount--)
+ { /* ignore all the certificates between the root and the signing CA */
+ uint32 ignorelen;
+ X509 *ignorecert;
+
+ DEBUG_RDP5(("Ignored certs left: %d\n", certcount));
+
+ in_uint32_le(s, ignorelen);
+ DEBUG_RDP5(("Ignored Certificate length is %d\n", ignorelen));
+ ignorecert = d2i_X509(NULL, &(s->p), ignorelen);
+
+ if(ignorecert == NULL)
+ { /* XXX: error out? */
+ DEBUG_RDP5(("got a bad cert: this will probably screw up the rest of the communication\n"));
+ }
+
+#ifdef WITH_DEBUG_RDP5
+ DEBUG_RDP5(("cert #%d (ignored):\n",certcount));
+ X509_print_fp(stdout, ignorecert);
+#endif
+ }
+
+ /* Do da funky X.509 stuffy
+
+ "How did I find out about this? I looked up and saw a
+ bright light and when I came to I had a scar on my forehead
+ and knew about X.500"
+ - Peter Gutman in a early version of
+ http://www.cs.auckland.ac.nz/~pgut001/pubs/x509guide.txt
+ */
+
+ in_uint32_le(s, cacert_len);
+ DEBUG_RDP5(("CA Certificate length is %d\n", cacert_len));
+ cacert = d2i_X509(NULL, &(s->p), cacert_len);
+ /* Note: We don't need to move s->p here - d2i_X509 is
+ "kind" enough to do it for us */
+ if (NULL == cacert)
+ {
+ error("Couldn't load CA Certificate from server\n");
+ return False;
+ }
+
+ /* Currently, we don't use the CA Certificate.
+ FIXME:
+ *) Verify the server certificate (server_cert) with the
+ CA certificate.
+ *) Store the CA Certificate with the hostname of the
+ server we are connecting to as key, and compare it
+ when we connect the next time, in order to prevent
+ MITM-attacks.
+ */
+
+ in_uint32_le(s, cert_len);
+ DEBUG_RDP5(("Certificate length is %d\n", cert_len));
+ server_cert = d2i_X509(NULL, &(s->p), cert_len);
+ if (NULL == server_cert)
+ {
+ error("Couldn't load Certificate from server\n");
+ return False;
+ }
+
+ in_uint8s(s, 16); /* Padding */
+
+ /* Note: Verifying the server certificate must be done here,
+ before sec_parse_public_key since we'll have to apply
+ serious violence to the key after this */
+
+ if (!sec_parse_x509_key(server_cert))
+ {
+ DEBUG_RDP5(("Didn't parse X509 correctly\n"));
+ return False;
+ }
+ return True; /* There's some garbage here we don't care about */
+ }
+ return s_check_end(s);
+}
+
+/* Process crypto information blob */
+static void
+sec_process_crypt_info(STREAM s)
+{
+ uint8 *server_random, *modulus, *exponent;
+ uint8 client_random[SEC_RANDOM_SIZE];
+ uint32 rc4_key_size;
+ uint8 inr[SEC_MODULUS_SIZE];
+
+ if (!sec_parse_crypt_info(s, &rc4_key_size, &server_random, &modulus, &exponent))
+ {
+ DEBUG(("Failed to parse crypt info\n"));
+ return;
+ }
+
+ DEBUG(("Generating client random\n"));
+ /* Generate a client random, and hence determine encryption keys */
+ /* This is what the MS client do: */
+ memset(inr, 0, SEC_RANDOM_SIZE);
+ /* *ARIGL!* Plaintext attack, anyone?
+ I tried doing:
+ generate_random(inr);
+ ..but that generates connection errors now and then (yes,
+ "now and then". Something like 0 to 3 attempts needed before a
+ successful connection. Nice. Not!
+ */
+
+ generate_random(client_random);
+ if (NULL != server_public_key)
+ { /* Which means we should use
+ RDP5-style encryption */
+
+ memcpy(inr + SEC_RANDOM_SIZE, client_random, SEC_RANDOM_SIZE);
+ reverse(inr + SEC_RANDOM_SIZE, SEC_RANDOM_SIZE);
+
+ RSA_public_encrypt(SEC_MODULUS_SIZE,
+ inr, sec_crypted_random, server_public_key, RSA_NO_PADDING);
+
+ reverse(sec_crypted_random, SEC_MODULUS_SIZE);
+
+ }
+ else
+ { /* RDP4-style encryption */
+ sec_rsa_encrypt(sec_crypted_random,
+ client_random, SEC_RANDOM_SIZE, modulus, exponent);
+ }
+ sec_generate_keys(client_random, server_random, rc4_key_size);
+}
+
+
+/* Process SRV_INFO, find RDP version supported by server */
+static void
+sec_process_srv_info(STREAM s)
+{
+ in_uint16_le(s, g_server_rdp_version);
+ DEBUG_RDP5(("Server RDP version is %d\n", g_server_rdp_version));
+/* if (1 == g_server_rdp_version)
+ g_use_rdp5 = 0; */
+}
+
+
+/* Process connect response data blob */
+void
+sec_process_mcs_data(STREAM s)
+{
+ uint16 tag, length;
+ uint8 *next_tag;
+ uint8 len;
+
+ in_uint8s(s, 21); /* header (T.124 stuff, probably) */
+ in_uint8(s, len);
+ if (len & 0x80)
+ in_uint8(s, len);
+
+ while (s->p < s->end)
+ {
+ in_uint16_le(s, tag);
+ in_uint16_le(s, length);
+
+ if (length <= 4)
+ return;
+
+ next_tag = s->p + length - 4;
+
+ switch (tag)
+ {
+ case SEC_TAG_SRV_INFO:
+ sec_process_srv_info(s);
+ break;
+
+ case SEC_TAG_SRV_CRYPT:
+ sec_process_crypt_info(s);
+ break;
+
+ case SEC_TAG_SRV_CHANNELS:
+ /* FIXME: We should parse this information and
+ use it to map RDP5 channels to MCS
+ channels */
+ break;
+
+ default:
+ unimpl("response tag 0x%x\n", tag);
+ }
+
+ s->p = next_tag;
+ }
+}
+
+/* Receive secure transport packet */
+STREAM
+sec_recv(void)
+{
+ uint32 sec_flags;
+ uint16 channel;
+ STREAM s;
+
+ while ((s = mcs_recv(&channel)) != NULL)
+ {
+ if (/*g_encryption || !g_licence_issued*/ 0)
+ {
+ in_uint32_le(s, sec_flags);
+
+ if (sec_flags & SEC_ENCRYPT)
+ {
+ in_uint8s(s, 8); /* signature */
+ sec_decrypt(s->p, s->end - s->p);
+ }
+
+ if (sec_flags & SEC_LICENCE_NEG)
+ {
+ licence_process(s);
+ continue;
+ }
+ }
+
+ if (channel != MCS_GLOBAL_CHANNEL)
+ {
+ channel_process(s, channel);
+ continue;
+ }
+
+ return s;
+ }
+
+ return NULL;
+}
+
+/* Disconnect a connection */
+void
+sec_disconnect(void)
+{
+ mcs_disconnect();
+}