Even more imports. Link to OpenSSL.
authorSteinar H. Gunderson <sgunderson@bigfoot.com>
Thu, 3 Feb 2005 22:46:49 +0000 (22:46 +0000)
committerSteinar H. Gunderson <sgunderson@bigfoot.com>
Thu, 3 Feb 2005 22:46:49 +0000 (22:46 +0000)
Makefile
channels.c [new file with mode: 0644]
mcs.c [new file with mode: 0644]
proto.h
rdpsrv.c
secure.c [new file with mode: 0644]
util.c

index fd811cf..f5da472 100644 (file)
--- a/Makefile
+++ b/Makefile
@@ -1,11 +1,12 @@
 CC=gcc
 CFLAGS=-g -Wall
+LIBS=-lssl
 
 all: rdpsrv
-OBJS=rdpsrv.o iso.o tcp.o util.o
+OBJS=rdpsrv.o iso.o tcp.o util.o mcs.o secure.o channels.o
 
 rdpsrv: $(OBJS)
-       $(CC) -o rdpsrv $(OBJS)
+       $(CC) -o rdpsrv $(OBJS) $(LIBS)
 clean:
        $(RM) $(OBJS) rdpsrv
 
diff --git a/channels.c b/channels.c
new file mode 100644 (file)
index 0000000..6fc0cde
--- /dev/null
@@ -0,0 +1,178 @@
+/* -*- 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);
+               }
+       }
+}
diff --git a/mcs.c b/mcs.c
new file mode 100644 (file)
index 0000000..ac8148b
--- /dev/null
+++ b/mcs.c
@@ -0,0 +1,379 @@
+/* -*- 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();
+}
diff --git a/proto.h b/proto.h
index b08a977..b371330 100644 (file)
--- a/proto.h
+++ b/proto.h
@@ -48,7 +48,6 @@ void process_orders(STREAM s, uint16 num_orders);
 void reset_order_state(void);
 /* printer.c */
 /* rdesktop.c */
-int main(int argc, char *argv[]);
 void generate_random(uint8 * random);
 void *xmalloc(int size);
 void *xrealloc(void *oldmem, int size);
index 5b1603d..8355426 100644 (file)
--- a/rdpsrv.c
+++ b/rdpsrv.c
@@ -6,6 +6,8 @@
 #include <sys/ioctl.h>
 #include <arpa/inet.h>
 
+#include "rdesktop.h"
+
 const int tcp_port_rdp = 3389;
 int create_server_socket();
 int serve_client(int sock);
@@ -69,8 +71,9 @@ int serve_client(int sock)
 {
        for ( ;; ) {
                unsigned char buf[4096];
+               short channel;
                
                /* receive ISO packets */
-               
+               mcs_recv(&channel);
        }
 }
diff --git a/secure.c b/secure.c
new file mode 100644 (file)
index 0000000..fd96936
--- /dev/null
+++ b/secure.c
@@ -0,0 +1,758 @@
+/* -*- 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();
+}
diff --git a/util.c b/util.c
index 2376a61..24365bf 100644 (file)
--- a/util.c
+++ b/util.c
@@ -75,6 +75,51 @@ generate_random_egd(uint8 * buf)
 }
 #endif
 
+/* Generate a 32-byte random for the secure transport code. */
+void
+generate_random(uint8 * random)
+{
+       struct stat st;
+       struct tms tmsbuf;
+       MD5_CTX md5;
+       uint32 *r;
+       int fd, n;
+
+       /* If we have a kernel random device, try that first */
+       if (((fd = open("/dev/urandom", O_RDONLY)) != -1)
+                       || ((fd = open("/dev/random", O_RDONLY)) != -1))
+       {
+               n = read(fd, random, 32);
+               close(fd);
+               if (n == 32)
+                       return;
+       }
+
+#ifdef EGD_SOCKET
+       /* As a second preference use an EGD */
+       if (generate_random_egd(random))
+               return;
+#endif
+
+       /* Otherwise use whatever entropy we can gather - ideas welcome. */
+       r = (uint32 *) random;
+       r[0] = (getpid()) | (getppid() << 16);
+       r[1] = (getuid()) | (getgid() << 16);
+       r[2] = times(&tmsbuf);  /* system uptime (clocks) */
+       gettimeofday((struct timeval *) &r[3], NULL);   /* sec and usec */
+       stat("/tmp", &st);
+       r[5] = st.st_atime;
+       r[6] = st.st_mtime;
+       r[7] = st.st_ctime;
+
+       /* Hash both halves with MD5 to obscure possible patterns */
+       MD5_Init(&md5);
+       MD5_Update(&md5, random, 16);
+       MD5_Final(random, &md5);
+       MD5_Update(&md5, random + 16, 16);
+       MD5_Final(random + 16, &md5);
+}
+
 /* malloc; exit if out of memory */
 void *
 xmalloc(int size)