/[rdesktop]/sourceforge.net/trunk/rdesktop/secure.c
This is repository of my old source code which isn't updated any more. Go to git.rot13.org for current projects!
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Diff of /sourceforge.net/trunk/rdesktop/secure.c

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revision 57 by matthewc, Sat Jul 13 02:30:49 2002 UTC revision 315 by jsorg71, Sun Feb 9 01:38:07 2003 UTC
# Line 1  Line 1 
1  /*  /*
2     rdesktop: A Remote Desktop Protocol client.     rdesktop: A Remote Desktop Protocol client.
3     Protocol services - RDP encryption and licensing     Protocol services - RDP encryption and licensing
4     Copyright (C) Matthew Chapman 1999-2001     Copyright (C) Matthew Chapman 1999-2002
5    
6     This program is free software; you can redistribute it and/or modify     This program is free software; you can redistribute it and/or modify
7     it under the terms of the GNU General Public License as published by     it under the terms of the GNU General Public License as published by
# Line 38  extern int height; Line 38  extern int height;
38  extern int keylayout;  extern int keylayout;
39  extern BOOL encryption;  extern BOOL encryption;
40  extern BOOL licence_issued;  extern BOOL licence_issued;
41    extern int server_bpp;
42    
43  static int rc4_key_len;  static int rc4_key_len;
44  static RC4_KEY rc4_decrypt_key;  static RC4_KEY rc4_decrypt_key;
# Line 56  static uint8 sec_crypted_random[SEC_MODU Line 57  static uint8 sec_crypted_random[SEC_MODU
57   * Both SHA1 and MD5 algorithms are used.   * Both SHA1 and MD5 algorithms are used.
58   */   */
59  void  void
60  sec_hash_48(uint8 *out, uint8 *in, uint8 *salt1, uint8 *salt2, uint8 salt)  sec_hash_48(uint8 * out, uint8 * in, uint8 * salt1, uint8 * salt2, uint8 salt)
61  {  {
62          uint8 shasig[20];          uint8 shasig[20];
63          uint8 pad[4];          uint8 pad[4];
# Line 87  sec_hash_48(uint8 *out, uint8 *in, uint8 Line 88  sec_hash_48(uint8 *out, uint8 *in, uint8
88   * only using a single round of MD5.   * only using a single round of MD5.
89   */   */
90  void  void
91  sec_hash_16(uint8 *out, uint8 *in, uint8 *salt1, uint8 *salt2)  sec_hash_16(uint8 * out, uint8 * in, uint8 * salt1, uint8 * salt2)
92  {  {
93          MD5_CTX md5;          MD5_CTX md5;
94    
# Line 100  sec_hash_16(uint8 *out, uint8 *in, uint8 Line 101  sec_hash_16(uint8 *out, uint8 *in, uint8
101    
102  /* Reduce key entropy from 64 to 40 bits */  /* Reduce key entropy from 64 to 40 bits */
103  static void  static void
104  sec_make_40bit(uint8 *key)  sec_make_40bit(uint8 * key)
105  {  {
106          key[0] = 0xd1;          key[0] = 0xd1;
107          key[1] = 0x26;          key[1] = 0x26;
# Line 109  sec_make_40bit(uint8 *key) Line 110  sec_make_40bit(uint8 *key)
110    
111  /* Generate a session key and RC4 keys, given client and server randoms */  /* Generate a session key and RC4 keys, given client and server randoms */
112  static void  static void
113  sec_generate_keys(uint8 *client_key, uint8 *server_key, int rc4_key_size)  sec_generate_keys(uint8 * client_key, uint8 * server_key, int rc4_key_size)
114  {  {
115          uint8 session_key[48];          uint8 session_key[48];
116          uint8 temp_hash[48];          uint8 temp_hash[48];
# Line 127  sec_generate_keys(uint8 *client_key, uin Line 128  sec_generate_keys(uint8 *client_key, uin
128          memcpy(sec_sign_key, session_key, 16);          memcpy(sec_sign_key, session_key, 16);
129    
130          /* Generate RC4 keys */          /* Generate RC4 keys */
131          sec_hash_16(sec_decrypt_key, &session_key[16], client_key,          sec_hash_16(sec_decrypt_key, &session_key[16], client_key, server_key);
132                      server_key);          sec_hash_16(sec_encrypt_key, &session_key[32], client_key, server_key);
         sec_hash_16(sec_encrypt_key, &session_key[32], client_key,  
                     server_key);  
133    
134          if (rc4_key_size == 1)          if (rc4_key_size == 1)
135          {          {
# Line 171  static uint8 pad_92[48] = { Line 170  static uint8 pad_92[48] = {
170    
171  /* Output a uint32 into a buffer (little-endian) */  /* Output a uint32 into a buffer (little-endian) */
172  void  void
173  buf_out_uint32(uint8 *buffer, uint32 value)  buf_out_uint32(uint8 * buffer, uint32 value)
174  {  {
175          buffer[0] = (value) & 0xff;          buffer[0] = (value) & 0xff;
176          buffer[1] = (value >> 8) & 0xff;          buffer[1] = (value >> 8) & 0xff;
# Line 181  buf_out_uint32(uint8 *buffer, uint32 val Line 180  buf_out_uint32(uint8 *buffer, uint32 val
180    
181  /* Generate a signature hash, using a combination of SHA1 and MD5 */  /* Generate a signature hash, using a combination of SHA1 and MD5 */
182  void  void
183  sec_sign(uint8 *signature, uint8 *session_key, int length,  sec_sign(uint8 * signature, int siglen, uint8 * session_key, int keylen, uint8 * data, int datalen)
          uint8 *data, int datalen)  
184  {  {
185          uint8 shasig[20];          uint8 shasig[20];
186          uint8 md5sig[16];          uint8 md5sig[16];
# Line 193  sec_sign(uint8 *signature, uint8 *sessio Line 191  sec_sign(uint8 *signature, uint8 *sessio
191          buf_out_uint32(lenhdr, datalen);          buf_out_uint32(lenhdr, datalen);
192    
193          SHA1_Init(&sha);          SHA1_Init(&sha);
194          SHA1_Update(&sha, session_key, rc4_key_len);          SHA1_Update(&sha, session_key, keylen);
195          SHA1_Update(&sha, pad_54, 40);          SHA1_Update(&sha, pad_54, 40);
196          SHA1_Update(&sha, lenhdr, 4);          SHA1_Update(&sha, lenhdr, 4);
197          SHA1_Update(&sha, data, datalen);          SHA1_Update(&sha, data, datalen);
198          SHA1_Final(shasig, &sha);          SHA1_Final(shasig, &sha);
199    
200          MD5_Init(&md5);          MD5_Init(&md5);
201          MD5_Update(&md5, session_key, rc4_key_len);          MD5_Update(&md5, session_key, keylen);
202          MD5_Update(&md5, pad_92, 48);          MD5_Update(&md5, pad_92, 48);
203          MD5_Update(&md5, shasig, 20);          MD5_Update(&md5, shasig, 20);
204          MD5_Final(md5sig, &md5);          MD5_Final(md5sig, &md5);
205    
206          memcpy(signature, md5sig, length);          memcpy(signature, md5sig, siglen);
207  }  }
208    
209  /* Update an encryption key - similar to the signing process */  /* Update an encryption key - similar to the signing process */
210  static void  static void
211  sec_update(uint8 *key, uint8 *update_key)  sec_update(uint8 * key, uint8 * update_key)
212  {  {
213          uint8 shasig[20];          uint8 shasig[20];
214          SHA_CTX sha;          SHA_CTX sha;
# Line 238  sec_update(uint8 *key, uint8 *update_key Line 236  sec_update(uint8 *key, uint8 *update_key
236    
237  /* Encrypt data using RC4 */  /* Encrypt data using RC4 */
238  static void  static void
239  sec_encrypt(uint8 *data, int length)  sec_encrypt(uint8 * data, int length)
240  {  {
241          static int use_count;          static int use_count;
242    
# Line 255  sec_encrypt(uint8 *data, int length) Line 253  sec_encrypt(uint8 *data, int length)
253    
254  /* Decrypt data using RC4 */  /* Decrypt data using RC4 */
255  static void  static void
256  sec_decrypt(uint8 *data, int length)  sec_decrypt(uint8 * data, int length)
257  {  {
258          static int use_count;          static int use_count;
259    
# Line 271  sec_decrypt(uint8 *data, int length) Line 269  sec_decrypt(uint8 *data, int length)
269  }  }
270    
271  static void  static void
272  reverse(uint8 *p, int len)  reverse(uint8 * p, int len)
273  {  {
274          int i, j;          int i, j;
275          uint8 temp;          uint8 temp;
276    
277          for (i = 0, j = len-1; i < j; i++, j--)          for (i = 0, j = len - 1; i < j; i++, j--)
278          {          {
279                  temp = p[i];                  temp = p[i];
280                  p[i] = p[j];                  p[i] = p[j];
# Line 286  reverse(uint8 *p, int len) Line 284  reverse(uint8 *p, int len)
284    
285  /* Perform an RSA public key encryption operation */  /* Perform an RSA public key encryption operation */
286  static void  static void
287  sec_rsa_encrypt(uint8 *out, uint8 *in, int len,  sec_rsa_encrypt(uint8 * out, uint8 * in, int len, uint8 * modulus, uint8 * exponent)
                 uint8 *modulus, uint8 *exponent)  
288  {  {
289          BN_CTX ctx;          BN_CTX *ctx;
290          BIGNUM mod, exp, x, y;          BIGNUM mod, exp, x, y;
291          uint8 inr[SEC_MODULUS_SIZE];          uint8 inr[SEC_MODULUS_SIZE];
292          int outlen;          int outlen;
# Line 299  sec_rsa_encrypt(uint8 *out, uint8 *in, i Line 296  sec_rsa_encrypt(uint8 *out, uint8 *in, i
296          memcpy(inr, in, len);          memcpy(inr, in, len);
297          reverse(inr, len);          reverse(inr, len);
298    
299          BN_CTX_init(&ctx);          ctx = BN_CTX_new();
300          BN_init(&mod);          BN_init(&mod);
301          BN_init(&exp);          BN_init(&exp);
302          BN_init(&x);          BN_init(&x);
# Line 308  sec_rsa_encrypt(uint8 *out, uint8 *in, i Line 305  sec_rsa_encrypt(uint8 *out, uint8 *in, i
305          BN_bin2bn(modulus, SEC_MODULUS_SIZE, &mod);          BN_bin2bn(modulus, SEC_MODULUS_SIZE, &mod);
306          BN_bin2bn(exponent, SEC_EXPONENT_SIZE, &exp);          BN_bin2bn(exponent, SEC_EXPONENT_SIZE, &exp);
307          BN_bin2bn(inr, len, &x);          BN_bin2bn(inr, len, &x);
308          BN_mod_exp(&y, &x, &exp, &mod, &ctx);          BN_mod_exp(&y, &x, &exp, &mod, ctx);
309          outlen = BN_bn2bin(&y, out);          outlen = BN_bn2bin(&y, out);
310          reverse(out, outlen);          reverse(out, outlen);
311          if (outlen < SEC_MODULUS_SIZE)          if (outlen < SEC_MODULUS_SIZE)
312                  memset(out+outlen, 0, SEC_MODULUS_SIZE-outlen);                  memset(out + outlen, 0, SEC_MODULUS_SIZE - outlen);
313    
314          BN_free(&y);          BN_free(&y);
315          BN_clear_free(&x);          BN_clear_free(&x);
316          BN_free(&exp);          BN_free(&exp);
317          BN_free(&mod);          BN_free(&mod);
318          BN_CTX_free(&ctx);          BN_CTX_free(ctx);
319  }  }
320    
321  /* Initialise secure transport packet */  /* Initialise secure transport packet */
# Line 358  sec_send(STREAM s, uint32 flags) Line 355  sec_send(STREAM s, uint32 flags)
355                  hexdump(s->p + 8, datalen);                  hexdump(s->p + 8, datalen);
356  #endif  #endif
357    
358                  sec_sign(s->p, sec_sign_key, 8, s->p + 8, datalen);                  sec_sign(s->p, 8, sec_sign_key, rc4_key_len, s->p + 8, datalen);
359                  sec_encrypt(s->p + 8, datalen);                  sec_encrypt(s->p + 8, datalen);
360          }          }
361    
# Line 367  sec_send(STREAM s, uint32 flags) Line 364  sec_send(STREAM s, uint32 flags)
364    
365  /* Transfer the client random to the server */  /* Transfer the client random to the server */
366  static void  static void
367  sec_establish_key()  sec_establish_key(void)
368  {  {
369          uint32 length = SEC_MODULUS_SIZE + SEC_PADDING_SIZE;          uint32 length = SEC_MODULUS_SIZE + SEC_PADDING_SIZE;
370          uint32 flags = SEC_CLIENT_RANDOM;          uint32 flags = SEC_CLIENT_RANDOM;
# Line 389  sec_out_mcs_data(STREAM s) Line 386  sec_out_mcs_data(STREAM s)
386  {  {
387          int hostlen = 2 * strlen(hostname);          int hostlen = 2 * strlen(hostname);
388    
389            if (hostlen > 30)
390                    hostlen = 30;
391    
392          out_uint16_be(s, 5);    /* unknown */          out_uint16_be(s, 5);    /* unknown */
393          out_uint16_be(s, 0x14);          out_uint16_be(s, 0x14);
394          out_uint8(s, 0x7c);          out_uint8(s, 0x7c);
# Line 426  sec_out_mcs_data(STREAM s) Line 426  sec_out_mcs_data(STREAM s)
426          out_uint32_le(s, 12);          out_uint32_le(s, 12);
427          out_uint8s(s, 64);      /* reserved? 4 + 12 doublewords */          out_uint8s(s, 64);      /* reserved? 4 + 12 doublewords */
428    
429          out_uint16(s, 0xca01);          switch (server_bpp)
430            {
431                    case 8:
432                            out_uint16_le(s, 0xca01);
433                            break;
434                    case 15:
435                            out_uint16_le(s, 0xca02);
436                            break;
437                    case 16:
438                            out_uint16_le(s, 0xca03);
439                            break;
440                    case 24:
441                            out_uint16_le(s, 0xca04);
442                            break;
443            }
444          out_uint16(s, 0);          out_uint16(s, 0);
445    
446          /* Client encryption settings */          /* Client encryption settings */
447          out_uint16_le(s, SEC_TAG_CLI_CRYPT);          out_uint16_le(s, SEC_TAG_CLI_CRYPT);
448          out_uint16(s, 8);       /* length */          out_uint16_le(s, 8);    /* length */
449          out_uint32_le(s, encryption ? 0x3 : 0); /* encryption supported, 128-bit supported */          out_uint32_le(s, encryption ? 0x3 : 0); /* encryption supported, 128-bit supported */
450          s_mark_end(s);          s_mark_end(s);
451  }  }
452    
453  /* Parse a public key structure */  /* Parse a public key structure */
454  static BOOL  static BOOL
455  sec_parse_public_key(STREAM s, uint8 **modulus, uint8 **exponent)  sec_parse_public_key(STREAM s, uint8 ** modulus, uint8 ** exponent)
456  {  {
457          uint32 magic, modulus_len;          uint32 magic, modulus_len;
458    
# Line 466  sec_parse_public_key(STREAM s, uint8 **m Line 480  sec_parse_public_key(STREAM s, uint8 **m
480    
481  /* Parse a crypto information structure */  /* Parse a crypto information structure */
482  static BOOL  static BOOL
483  sec_parse_crypt_info(STREAM s, uint32 *rc4_key_size,  sec_parse_crypt_info(STREAM s, uint32 * rc4_key_size,
484                       uint8 **server_random, uint8 **modulus, uint8 **exponent)                       uint8 ** server_random, uint8 ** modulus, uint8 ** exponent)
485  {  {
486          uint32 crypt_level, random_len, rsa_info_len;          uint32 crypt_level, random_len, rsa_info_len;
487          uint16 tag, length;          uint16 tag, length;
# Line 475  sec_parse_crypt_info(STREAM s, uint32 *r Line 489  sec_parse_crypt_info(STREAM s, uint32 *r
489    
490          in_uint32_le(s, *rc4_key_size); /* 1 = 40-bit, 2 = 128-bit */          in_uint32_le(s, *rc4_key_size); /* 1 = 40-bit, 2 = 128-bit */
491          in_uint32_le(s, crypt_level);   /* 1 = low, 2 = medium, 3 = high */          in_uint32_le(s, crypt_level);   /* 1 = low, 2 = medium, 3 = high */
492            if (crypt_level == 0)   /* no encryptation */
493                    return False;
494          in_uint32_le(s, random_len);          in_uint32_le(s, random_len);
495          in_uint32_le(s, rsa_info_len);          in_uint32_le(s, rsa_info_len);
496    
# Line 503  sec_parse_crypt_info(STREAM s, uint32 *r Line 519  sec_parse_crypt_info(STREAM s, uint32 *r
519                  switch (tag)                  switch (tag)
520                  {                  {
521                          case SEC_TAG_PUBKEY:                          case SEC_TAG_PUBKEY:
522                                  if (!sec_parse_public_key                                  if (!sec_parse_public_key(s, modulus, exponent))
                                     (s, modulus, exponent))  
523                                          return False;                                          return False;
524    
525                                  break;                                  break;
# Line 532  sec_process_crypt_info(STREAM s) Line 547  sec_process_crypt_info(STREAM s)
547          uint8 client_random[SEC_RANDOM_SIZE];          uint8 client_random[SEC_RANDOM_SIZE];
548          uint32 rc4_key_size;          uint32 rc4_key_size;
549    
550          if (!sec_parse_crypt_info(s, &rc4_key_size, &server_random,          if (!sec_parse_crypt_info(s, &rc4_key_size, &server_random, &modulus, &exponent))
                                   &modulus, &exponent))  
551                  return;                  return;
552    
553          /* Generate a client random, and hence determine encryption keys */          /* Generate a client random, and hence determine encryption keys */
554          generate_random(client_random);          generate_random(client_random);
555          sec_rsa_encrypt(sec_crypted_random, client_random,          sec_rsa_encrypt(sec_crypted_random, client_random, SEC_RANDOM_SIZE, modulus, exponent);
                         SEC_RANDOM_SIZE, modulus, exponent);  
556          sec_generate_keys(client_random, server_random, rc4_key_size);          sec_generate_keys(client_random, server_random, rc4_key_size);
557  }  }
558    
# Line 549  sec_process_mcs_data(STREAM s) Line 562  sec_process_mcs_data(STREAM s)
562  {  {
563          uint16 tag, length;          uint16 tag, length;
564          uint8 *next_tag;          uint8 *next_tag;
565            uint8 len;
566    
567          in_uint8s(s, 23);       /* header */          in_uint8s(s, 21);       /* header */
568            in_uint8(s, len);
569            if (len & 0x80)
570                    in_uint8(s, len);
571    
572          while (s->p < s->end)          while (s->p < s->end)
573          {          {
# Line 582  sec_process_mcs_data(STREAM s) Line 599  sec_process_mcs_data(STREAM s)
599    
600  /* Receive secure transport packet */  /* Receive secure transport packet */
601  STREAM  STREAM
602  sec_recv()  sec_recv(void)
603  {  {
604          uint32 sec_flags;          uint32 sec_flags;
605          STREAM s;          STREAM s;
# Line 629  sec_connect(char *server) Line 646  sec_connect(char *server)
646          sec_process_mcs_data(&mcs_data);          sec_process_mcs_data(&mcs_data);
647          if (encryption)          if (encryption)
648                  sec_establish_key();                  sec_establish_key();
649            xfree(mcs_data.data);
650          return True;          return True;
651  }  }
652    
653  /* Disconnect a connection */  /* Disconnect a connection */
654  void  void
655  sec_disconnect()  sec_disconnect(void)
656  {  {
657          mcs_disconnect();          mcs_disconnect();
658  }  }
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