FreeRDP
libfreerdp/core/security.c
1 
21 #include <freerdp/config.h>
22 
23 #include "settings.h"
24 #include "security.h"
25 
26 #include <freerdp/log.h>
27 #include <winpr/crypto.h>
28 
29 #define TAG FREERDP_TAG("core")
30 
31 static const BYTE A[] = { 'A' };
32 static const BYTE BB[] = { 'B', 'B' };
33 static const BYTE CCC[] = { 'C', 'C', 'C' };
34 
35 /* 0x36 repeated 40 times */
36 static const BYTE pad1[40] = { "\x36\x36\x36\x36\x36\x36\x36\x36"
37  "\x36\x36\x36\x36\x36\x36\x36\x36"
38  "\x36\x36\x36\x36\x36\x36\x36\x36"
39  "\x36\x36\x36\x36\x36\x36\x36\x36"
40  "\x36\x36\x36\x36\x36\x36\x36\x36" };
41 
42 /* 0x5C repeated 48 times */
43 static const BYTE pad2[48] = { "\x5C\x5C\x5C\x5C\x5C\x5C\x5C\x5C"
44  "\x5C\x5C\x5C\x5C\x5C\x5C\x5C\x5C"
45  "\x5C\x5C\x5C\x5C\x5C\x5C\x5C\x5C"
46  "\x5C\x5C\x5C\x5C\x5C\x5C\x5C\x5C"
47  "\x5C\x5C\x5C\x5C\x5C\x5C\x5C\x5C"
48  "\x5C\x5C\x5C\x5C\x5C\x5C\x5C\x5C" };
49 
50 static const BYTE fips_reverse_table[256] = {
51  0x00, 0x80, 0x40, 0xc0, 0x20, 0xa0, 0x60, 0xe0, 0x10, 0x90, 0x50, 0xd0, 0x30, 0xb0, 0x70, 0xf0,
52  0x08, 0x88, 0x48, 0xc8, 0x28, 0xa8, 0x68, 0xe8, 0x18, 0x98, 0x58, 0xd8, 0x38, 0xb8, 0x78, 0xf8,
53  0x04, 0x84, 0x44, 0xc4, 0x24, 0xa4, 0x64, 0xe4, 0x14, 0x94, 0x54, 0xd4, 0x34, 0xb4, 0x74, 0xf4,
54  0x0c, 0x8c, 0x4c, 0xcc, 0x2c, 0xac, 0x6c, 0xec, 0x1c, 0x9c, 0x5c, 0xdc, 0x3c, 0xbc, 0x7c, 0xfc,
55  0x02, 0x82, 0x42, 0xc2, 0x22, 0xa2, 0x62, 0xe2, 0x12, 0x92, 0x52, 0xd2, 0x32, 0xb2, 0x72, 0xf2,
56  0x0a, 0x8a, 0x4a, 0xca, 0x2a, 0xaa, 0x6a, 0xea, 0x1a, 0x9a, 0x5a, 0xda, 0x3a, 0xba, 0x7a, 0xfa,
57  0x06, 0x86, 0x46, 0xc6, 0x26, 0xa6, 0x66, 0xe6, 0x16, 0x96, 0x56, 0xd6, 0x36, 0xb6, 0x76, 0xf6,
58  0x0e, 0x8e, 0x4e, 0xce, 0x2e, 0xae, 0x6e, 0xee, 0x1e, 0x9e, 0x5e, 0xde, 0x3e, 0xbe, 0x7e, 0xfe,
59  0x01, 0x81, 0x41, 0xc1, 0x21, 0xa1, 0x61, 0xe1, 0x11, 0x91, 0x51, 0xd1, 0x31, 0xb1, 0x71, 0xf1,
60  0x09, 0x89, 0x49, 0xc9, 0x29, 0xa9, 0x69, 0xe9, 0x19, 0x99, 0x59, 0xd9, 0x39, 0xb9, 0x79, 0xf9,
61  0x05, 0x85, 0x45, 0xc5, 0x25, 0xa5, 0x65, 0xe5, 0x15, 0x95, 0x55, 0xd5, 0x35, 0xb5, 0x75, 0xf5,
62  0x0d, 0x8d, 0x4d, 0xcd, 0x2d, 0xad, 0x6d, 0xed, 0x1d, 0x9d, 0x5d, 0xdd, 0x3d, 0xbd, 0x7d, 0xfd,
63  0x03, 0x83, 0x43, 0xc3, 0x23, 0xa3, 0x63, 0xe3, 0x13, 0x93, 0x53, 0xd3, 0x33, 0xb3, 0x73, 0xf3,
64  0x0b, 0x8b, 0x4b, 0xcb, 0x2b, 0xab, 0x6b, 0xeb, 0x1b, 0x9b, 0x5b, 0xdb, 0x3b, 0xbb, 0x7b, 0xfb,
65  0x07, 0x87, 0x47, 0xc7, 0x27, 0xa7, 0x67, 0xe7, 0x17, 0x97, 0x57, 0xd7, 0x37, 0xb7, 0x77, 0xf7,
66  0x0f, 0x8f, 0x4f, 0xcf, 0x2f, 0xaf, 0x6f, 0xef, 0x1f, 0x9f, 0x5f, 0xdf, 0x3f, 0xbf, 0x7f, 0xff
67 };
68 
69 static const BYTE fips_oddparity_table[256] = {
70  0x01, 0x01, 0x02, 0x02, 0x04, 0x04, 0x07, 0x07, 0x08, 0x08, 0x0b, 0x0b, 0x0d, 0x0d, 0x0e, 0x0e,
71  0x10, 0x10, 0x13, 0x13, 0x15, 0x15, 0x16, 0x16, 0x19, 0x19, 0x1a, 0x1a, 0x1c, 0x1c, 0x1f, 0x1f,
72  0x20, 0x20, 0x23, 0x23, 0x25, 0x25, 0x26, 0x26, 0x29, 0x29, 0x2a, 0x2a, 0x2c, 0x2c, 0x2f, 0x2f,
73  0x31, 0x31, 0x32, 0x32, 0x34, 0x34, 0x37, 0x37, 0x38, 0x38, 0x3b, 0x3b, 0x3d, 0x3d, 0x3e, 0x3e,
74  0x40, 0x40, 0x43, 0x43, 0x45, 0x45, 0x46, 0x46, 0x49, 0x49, 0x4a, 0x4a, 0x4c, 0x4c, 0x4f, 0x4f,
75  0x51, 0x51, 0x52, 0x52, 0x54, 0x54, 0x57, 0x57, 0x58, 0x58, 0x5b, 0x5b, 0x5d, 0x5d, 0x5e, 0x5e,
76  0x61, 0x61, 0x62, 0x62, 0x64, 0x64, 0x67, 0x67, 0x68, 0x68, 0x6b, 0x6b, 0x6d, 0x6d, 0x6e, 0x6e,
77  0x70, 0x70, 0x73, 0x73, 0x75, 0x75, 0x76, 0x76, 0x79, 0x79, 0x7a, 0x7a, 0x7c, 0x7c, 0x7f, 0x7f,
78  0x80, 0x80, 0x83, 0x83, 0x85, 0x85, 0x86, 0x86, 0x89, 0x89, 0x8a, 0x8a, 0x8c, 0x8c, 0x8f, 0x8f,
79  0x91, 0x91, 0x92, 0x92, 0x94, 0x94, 0x97, 0x97, 0x98, 0x98, 0x9b, 0x9b, 0x9d, 0x9d, 0x9e, 0x9e,
80  0xa1, 0xa1, 0xa2, 0xa2, 0xa4, 0xa4, 0xa7, 0xa7, 0xa8, 0xa8, 0xab, 0xab, 0xad, 0xad, 0xae, 0xae,
81  0xb0, 0xb0, 0xb3, 0xb3, 0xb5, 0xb5, 0xb6, 0xb6, 0xb9, 0xb9, 0xba, 0xba, 0xbc, 0xbc, 0xbf, 0xbf,
82  0xc1, 0xc1, 0xc2, 0xc2, 0xc4, 0xc4, 0xc7, 0xc7, 0xc8, 0xc8, 0xcb, 0xcb, 0xcd, 0xcd, 0xce, 0xce,
83  0xd0, 0xd0, 0xd3, 0xd3, 0xd5, 0xd5, 0xd6, 0xd6, 0xd9, 0xd9, 0xda, 0xda, 0xdc, 0xdc, 0xdf, 0xdf,
84  0xe0, 0xe0, 0xe3, 0xe3, 0xe5, 0xe5, 0xe6, 0xe6, 0xe9, 0xe9, 0xea, 0xea, 0xec, 0xec, 0xef, 0xef,
85  0xf1, 0xf1, 0xf2, 0xf2, 0xf4, 0xf4, 0xf7, 0xf7, 0xf8, 0xf8, 0xfb, 0xfb, 0xfd, 0xfd, 0xfe, 0xfe
86 };
87 
88 static BOOL security_salted_hash(const BYTE* salt, size_t salt_len, const BYTE* input,
89  size_t length, const BYTE* salt1, size_t salt1_len,
90  const BYTE* salt2, size_t salt2_len, BYTE* output, size_t out_len)
91 {
92  WINPR_DIGEST_CTX* sha1 = NULL;
93  WINPR_DIGEST_CTX* md5 = NULL;
94  BYTE sha1_digest[WINPR_SHA1_DIGEST_LENGTH] = { 0 };
95  BOOL result = FALSE;
96 
97  /* SaltedHash(Salt, Input, Salt1, Salt2) = MD5(S + SHA1(Input + Salt + Salt1 + Salt2)) */
98  WINPR_ASSERT(out_len >= WINPR_MD5_DIGEST_LENGTH);
99 
100  /* SHA1_Digest = SHA1(Input + Salt + Salt1 + Salt2) */
101  if (!(sha1 = winpr_Digest_New()))
102  goto out;
103 
104  if (!winpr_Digest_Init(sha1, WINPR_MD_SHA1))
105  goto out;
106 
107  if (!winpr_Digest_Update(sha1, input, length)) /* Input */
108  goto out;
109 
110  WINPR_ASSERT(salt_len == 48);
111  if (!winpr_Digest_Update(sha1, salt, salt_len)) /* Salt (48 bytes) */
112  goto out;
113 
114  WINPR_ASSERT(salt1_len == 32);
115  if (!winpr_Digest_Update(sha1, salt1, salt1_len)) /* Salt1 (32 bytes) */
116  goto out;
117 
118  WINPR_ASSERT(salt2_len == 32);
119  if (!winpr_Digest_Update(sha1, salt2, salt2_len)) /* Salt2 (32 bytes) */
120  goto out;
121 
122  if (!winpr_Digest_Final(sha1, sha1_digest, sizeof(sha1_digest)))
123  goto out;
124 
125  /* SaltedHash(Salt, Input, Salt1, Salt2) = MD5(S + SHA1_Digest) */
126  if (!(md5 = winpr_Digest_New()))
127  goto out;
128 
129  /* Allow FIPS override for use of MD5 here, this is used for creating hashes of the
130  * premaster_secret and master_secret */
131  /* used for RDP licensing as described in MS-RDPELE. This is for RDP licensing packets */
132  /* which will already be encrypted under FIPS, so the use of MD5 here is not for sensitive data
133  * protection. */
134  if (!winpr_Digest_Init_Allow_FIPS(md5, WINPR_MD_MD5))
135  goto out;
136 
137  if (!winpr_Digest_Update(md5, salt, 48)) /* Salt (48 bytes) */
138  goto out;
139 
140  if (!winpr_Digest_Update(md5, sha1_digest, sizeof(sha1_digest))) /* SHA1_Digest */
141  goto out;
142 
143  if (!winpr_Digest_Final(md5, output, out_len))
144  goto out;
145 
146  result = TRUE;
147 out:
148  winpr_Digest_Free(sha1);
149  winpr_Digest_Free(md5);
150  return result;
151 }
152 
153 static BOOL security_premaster_hash(const BYTE* input, size_t length, const BYTE* premaster_secret,
154  size_t pre_len, const BYTE* client_random, size_t client_len,
155  const BYTE* server_random, size_t server_len, BYTE* output,
156  size_t out_len)
157 {
158  /* PremasterHash(Input) = SaltedHash(PremasterSecret, Input, ClientRandom, ServerRandom) */
159  return security_salted_hash(premaster_secret, pre_len, input, length, client_random, client_len,
160  server_random, server_len, output, out_len);
161 }
162 
163 BOOL security_master_secret(const BYTE* premaster_secret, size_t pre_len, const BYTE* client_random,
164  size_t client_len, const BYTE* server_random, size_t server_len,
165  BYTE* output, size_t out_len)
166 {
167  /* MasterSecret = PremasterHash('A') + PremasterHash('BB') + PremasterHash('CCC') */
168  WINPR_ASSERT(out_len >= 32);
169  return security_premaster_hash(A, sizeof(A), premaster_secret, pre_len, client_random,
170  client_len, server_random, server_len, &output[0], out_len) &&
171  security_premaster_hash(BB, sizeof(BB), premaster_secret, pre_len, client_random,
172  client_len, server_random, server_len, &output[16],
173  out_len - 16) &&
174  security_premaster_hash(CCC, sizeof(CCC), premaster_secret, pre_len, client_random,
175  client_len, server_random, server_len, &output[32],
176  out_len - 32);
177 }
178 
179 static BOOL security_master_hash(const BYTE* input, size_t length, const BYTE* master_secret,
180  size_t master_len, const BYTE* client_random, size_t client_len,
181  const BYTE* server_random, size_t server_len, BYTE* output,
182  size_t out_len)
183 {
184  /* MasterHash(Input) = SaltedHash(MasterSecret, Input, ServerRandom, ClientRandom) */
185  return security_salted_hash(master_secret, master_len, input, length, server_random, server_len,
186  client_random, client_len, output, out_len);
187 }
188 
189 BOOL security_session_key_blob(const BYTE* master_secret, size_t master_len,
190  const BYTE* client_random, size_t client_len,
191  const BYTE* server_random, size_t server_len, BYTE* output,
192  size_t out_len)
193 {
194  /* MasterHash = MasterHash('A') + MasterHash('BB') + MasterHash('CCC') */
195  WINPR_ASSERT(out_len >= 32);
196  return security_master_hash(A, sizeof(A), master_secret, master_len, client_random, client_len,
197  server_random, server_len, &output[0], 16) &&
198  security_master_hash(BB, sizeof(BB), master_secret, master_len, client_random,
199  client_len, server_random, server_len, &output[16], 16) &&
200  security_master_hash(CCC, sizeof(CCC), master_secret, master_len, client_random,
201  client_len, server_random, server_len, &output[32], out_len - 32);
202 }
203 
204 void security_mac_salt_key(const BYTE* session_key_blob, size_t session_len,
205  const BYTE* client_random, size_t client_len, const BYTE* server_random,
206  size_t server_len, BYTE* output, size_t out_len)
207 {
208  /* MacSaltKey = First128Bits(SessionKeyBlob) */
209  WINPR_ASSERT(out_len >= 16);
210  WINPR_ASSERT(session_len >= 16);
211  WINPR_UNUSED(client_random);
212  WINPR_UNUSED(client_len);
213  WINPR_UNUSED(server_random);
214  WINPR_UNUSED(server_len);
215  memcpy(output, session_key_blob, 16);
216 }
217 
218 static BOOL security_md5_16_32_32(const BYTE* in0, const BYTE* in1, const BYTE* in2, BYTE* output,
219  size_t out_len)
220 {
221  WINPR_DIGEST_CTX* md5 = NULL;
222  BOOL result = FALSE;
223 
224  WINPR_ASSERT(WINPR_MD5_DIGEST_LENGTH <= out_len);
225 
226  if (!(md5 = winpr_Digest_New()))
227  return FALSE;
228 
229  if (!winpr_Digest_Init(md5, WINPR_MD_MD5))
230  goto out;
231 
232  if (!winpr_Digest_Update(md5, in0, 16))
233  goto out;
234 
235  if (!winpr_Digest_Update(md5, in1, 32))
236  goto out;
237 
238  if (!winpr_Digest_Update(md5, in2, 32))
239  goto out;
240 
241  if (!winpr_Digest_Final(md5, output, out_len))
242  goto out;
243 
244  result = TRUE;
245 out:
246  winpr_Digest_Free(md5);
247  return result;
248 }
249 
250 static BOOL security_md5_16_32_32_Allow_FIPS(const BYTE* in0, const BYTE* in1, const BYTE* in2,
251  BYTE* output, size_t out_len)
252 {
253  WINPR_DIGEST_CTX* md5 = NULL;
254  BOOL result = FALSE;
255 
256  WINPR_ASSERT(out_len >= WINPR_MD5_DIGEST_LENGTH);
257 
258  if (!(md5 = winpr_Digest_New()))
259  return FALSE;
260  if (!winpr_Digest_Init_Allow_FIPS(md5, WINPR_MD_MD5))
261  goto out;
262  if (!winpr_Digest_Update(md5, in0, 16))
263  goto out;
264  if (!winpr_Digest_Update(md5, in1, 32))
265  goto out;
266  if (!winpr_Digest_Update(md5, in2, 32))
267  goto out;
268  if (!winpr_Digest_Final(md5, output, out_len))
269  goto out;
270 
271  result = TRUE;
272 out:
273  winpr_Digest_Free(md5);
274  return result;
275 }
276 
277 BOOL security_licensing_encryption_key(const BYTE* session_key_blob, size_t session_len,
278  const BYTE* client_random, size_t client_len,
279  const BYTE* server_random, size_t server_len, BYTE* output,
280  size_t out_len)
281 {
282  if (session_len < 16)
283  return FALSE;
284  if (client_len < 32)
285  return FALSE;
286  if (server_len < 32)
287  return FALSE;
288  /* LicensingEncryptionKey = MD5(Second128Bits(SessionKeyBlob) + ClientRandom + ServerRandom))
289  * Allow FIPS use of MD5 here, this is just used for creating the licensing encryption key as
290  * described in MS-RDPELE. This is for RDP licensing packets which will already be encrypted
291  * under FIPS, so the use of MD5 here is not for sensitive data protection. */
292  return security_md5_16_32_32_Allow_FIPS(&session_key_blob[16], client_random, server_random,
293  output, out_len);
294 }
295 
296 static void security_UINT32_le(BYTE* output, size_t out_len, UINT32 value)
297 {
298  WINPR_ASSERT(output);
299  WINPR_ASSERT(out_len >= 4);
300  output[0] = (value)&0xFF;
301  output[1] = (value >> 8) & 0xFF;
302  output[2] = (value >> 16) & 0xFF;
303  output[3] = (value >> 24) & 0xFF;
304 }
305 
306 BOOL security_mac_data(const BYTE* mac_salt_key, size_t mac_salt_key_length, const BYTE* data,
307  size_t length, BYTE* output, size_t output_length)
308 {
309  WINPR_DIGEST_CTX* sha1 = NULL;
310  WINPR_DIGEST_CTX* md5 = NULL;
311  BYTE length_le[4] = { 0 };
312  BYTE sha1_digest[WINPR_SHA1_DIGEST_LENGTH] = { 0 };
313  BOOL result = FALSE;
314 
315  WINPR_ASSERT(length <= UINT32_MAX);
316  WINPR_ASSERT(mac_salt_key_length == WINPR_MD5_DIGEST_LENGTH);
317  WINPR_ASSERT(output_length == WINPR_MD5_DIGEST_LENGTH);
318 
319  /* MacData = MD5(MacSaltKey + pad2 + SHA1(MacSaltKey + pad1 + length + data)) */
320  security_UINT32_le(length_le, sizeof(length_le),
321  (UINT32)length); /* length must be little-endian */
322 
323  /* SHA1_Digest = SHA1(MacSaltKey + pad1 + length + data) */
324  if (!(sha1 = winpr_Digest_New()))
325  goto out;
326 
327  if (!winpr_Digest_Init(sha1, WINPR_MD_SHA1))
328  goto out;
329 
330  if (!winpr_Digest_Update(sha1, mac_salt_key, mac_salt_key_length)) /* MacSaltKey */
331  goto out;
332 
333  if (!winpr_Digest_Update(sha1, pad1, sizeof(pad1))) /* pad1 */
334  goto out;
335 
336  if (!winpr_Digest_Update(sha1, length_le, sizeof(length_le))) /* length */
337  goto out;
338 
339  if (!winpr_Digest_Update(sha1, data, length)) /* data */
340  goto out;
341 
342  if (!winpr_Digest_Final(sha1, sha1_digest, sizeof(sha1_digest)))
343  goto out;
344 
345  /* MacData = MD5(MacSaltKey + pad2 + SHA1_Digest) */
346  if (!(md5 = winpr_Digest_New()))
347  goto out;
348 
349  /* Allow FIPS override for use of MD5 here, this is only used for creating the MACData field of
350  * the */
351  /* Client Platform Challenge Response packet (from MS-RDPELE section 2.2.2.5). This is for RDP
352  * licensing packets */
353  /* which will already be encrypted under FIPS, so the use of MD5 here is not for sensitive data
354  * protection. */
355  if (!winpr_Digest_Init_Allow_FIPS(md5, WINPR_MD_MD5))
356  goto out;
357 
358  if (!winpr_Digest_Update(md5, mac_salt_key, 16)) /* MacSaltKey */
359  goto out;
360 
361  if (!winpr_Digest_Update(md5, pad2, sizeof(pad2))) /* pad2 */
362  goto out;
363 
364  if (!winpr_Digest_Update(md5, sha1_digest, sizeof(sha1_digest))) /* SHA1_Digest */
365  goto out;
366 
367  if (!winpr_Digest_Final(md5, output, output_length))
368  goto out;
369 
370  result = TRUE;
371 out:
372  if (!result)
373  WLog_ERR(TAG, "failed to create security mac");
374  winpr_Digest_Free(sha1);
375  winpr_Digest_Free(md5);
376  return result;
377 }
378 
379 BOOL security_mac_signature(rdpRdp* rdp, const BYTE* data, UINT32 length, BYTE* output,
380  size_t out_len)
381 {
382  WINPR_DIGEST_CTX* sha1 = NULL;
383  WINPR_DIGEST_CTX* md5 = NULL;
384  BYTE length_le[4] = { 0 };
385  BYTE md5_digest[WINPR_MD5_DIGEST_LENGTH] = { 0 };
386  BYTE sha1_digest[WINPR_SHA1_DIGEST_LENGTH] = { 0 };
387  BOOL result = FALSE;
388 
389  WINPR_ASSERT(rdp);
390  WINPR_ASSERT(data || (length == 0));
391  WINPR_ASSERT(output);
392  WINPR_ASSERT(out_len >= 8);
393 
394  security_UINT32_le(length_le, sizeof(length_le), length); /* length must be little-endian */
395 
396  /* SHA1_Digest = SHA1(MACKeyN + pad1 + length + data) */
397  if (!(sha1 = winpr_Digest_New()))
398  goto out;
399 
400  if (!winpr_Digest_Init(sha1, WINPR_MD_SHA1))
401  goto out;
402 
403  if (!winpr_Digest_Update(sha1, rdp->sign_key, rdp->rc4_key_len)) /* MacKeyN */
404  goto out;
405 
406  if (!winpr_Digest_Update(sha1, pad1, sizeof(pad1))) /* pad1 */
407  goto out;
408 
409  if (!winpr_Digest_Update(sha1, length_le, sizeof(length_le))) /* length */
410  goto out;
411 
412  if (!winpr_Digest_Update(sha1, data, length)) /* data */
413  goto out;
414 
415  if (!winpr_Digest_Final(sha1, sha1_digest, sizeof(sha1_digest)))
416  goto out;
417 
418  /* MACSignature = First64Bits(MD5(MACKeyN + pad2 + SHA1_Digest)) */
419  if (!(md5 = winpr_Digest_New()))
420  goto out;
421 
422  if (!winpr_Digest_Init(md5, WINPR_MD_MD5))
423  goto out;
424 
425  if (!winpr_Digest_Update(md5, rdp->sign_key, rdp->rc4_key_len)) /* MacKeyN */
426  goto out;
427 
428  if (!winpr_Digest_Update(md5, pad2, sizeof(pad2))) /* pad2 */
429  goto out;
430 
431  if (!winpr_Digest_Update(md5, sha1_digest, sizeof(sha1_digest))) /* SHA1_Digest */
432  goto out;
433 
434  if (!winpr_Digest_Final(md5, md5_digest, sizeof(md5_digest)))
435  goto out;
436 
437  memcpy(output, md5_digest, 8);
438  result = TRUE;
439 out:
440  if (!result)
441  WLog_WARN(TAG, "security mac generation failed");
442  winpr_Digest_Free(sha1);
443  winpr_Digest_Free(md5);
444  return result;
445 }
446 
447 BOOL security_salted_mac_signature(rdpRdp* rdp, const BYTE* data, UINT32 length, BOOL encryption,
448  BYTE* output, size_t out_len)
449 {
450  WINPR_DIGEST_CTX* sha1 = NULL;
451  WINPR_DIGEST_CTX* md5 = NULL;
452  BYTE length_le[4] = { 0 };
453  BYTE use_count_le[4] = { 0 };
454  BYTE md5_digest[WINPR_MD5_DIGEST_LENGTH] = { 0 };
455  BYTE sha1_digest[WINPR_SHA1_DIGEST_LENGTH] = { 0 };
456  BOOL result = FALSE;
457 
458  WINPR_ASSERT(rdp);
459  WINPR_ASSERT(data || (length == 0));
460  WINPR_ASSERT(output);
461  WINPR_ASSERT(out_len >= 8);
462 
463  security_UINT32_le(length_le, sizeof(length_le), length); /* length must be little-endian */
464 
465  if (encryption)
466  {
467  security_UINT32_le(use_count_le, sizeof(use_count_le), rdp->encrypt_checksum_use_count);
468  }
469  else
470  {
471  /*
472  * We calculate checksum on plain text, so we must have already
473  * decrypt it, which means decrypt_checksum_use_count is off by one.
474  */
475  security_UINT32_le(use_count_le, sizeof(use_count_le),
476  rdp->decrypt_checksum_use_count - 1u);
477  }
478 
479  /* SHA1_Digest = SHA1(MACKeyN + pad1 + length + data) */
480  if (!(sha1 = winpr_Digest_New()))
481  goto out;
482 
483  if (!winpr_Digest_Init(sha1, WINPR_MD_SHA1))
484  goto out;
485 
486  if (!winpr_Digest_Update(sha1, rdp->sign_key, rdp->rc4_key_len)) /* MacKeyN */
487  goto out;
488 
489  if (!winpr_Digest_Update(sha1, pad1, sizeof(pad1))) /* pad1 */
490  goto out;
491 
492  if (!winpr_Digest_Update(sha1, length_le, sizeof(length_le))) /* length */
493  goto out;
494 
495  if (!winpr_Digest_Update(sha1, data, length)) /* data */
496  goto out;
497 
498  if (!winpr_Digest_Update(sha1, use_count_le, sizeof(use_count_le))) /* encryptionCount */
499  goto out;
500 
501  if (!winpr_Digest_Final(sha1, sha1_digest, sizeof(sha1_digest)))
502  goto out;
503 
504  /* MACSignature = First64Bits(MD5(MACKeyN + pad2 + SHA1_Digest)) */
505  if (!(md5 = winpr_Digest_New()))
506  goto out;
507 
508  if (!winpr_Digest_Init(md5, WINPR_MD_MD5))
509  goto out;
510 
511  if (!winpr_Digest_Update(md5, rdp->sign_key, rdp->rc4_key_len)) /* MacKeyN */
512  goto out;
513 
514  if (!winpr_Digest_Update(md5, pad2, sizeof(pad2))) /* pad2 */
515  goto out;
516 
517  if (!winpr_Digest_Update(md5, sha1_digest, sizeof(sha1_digest))) /* SHA1_Digest */
518  goto out;
519 
520  if (!winpr_Digest_Final(md5, md5_digest, sizeof(md5_digest)))
521  goto out;
522 
523  memcpy(output, md5_digest, 8);
524  result = TRUE;
525 out:
526  if (!result)
527  WLog_WARN(TAG, "security mac signature generation failed");
528 
529  winpr_Digest_Free(sha1);
530  winpr_Digest_Free(md5);
531  return result;
532 }
533 
534 static BOOL security_A(const BYTE* master_secret, size_t master_len, const BYTE* client_random,
535  size_t client_len, const BYTE* server_random, size_t server_len,
536  BYTE* output, size_t out_len)
537 {
538  WINPR_ASSERT(out_len >= 32);
539 
540  return security_premaster_hash(A, sizeof(A), master_secret, master_len, client_random,
541  client_len, server_random, server_len, &output[0], 16) &&
542  security_premaster_hash(BB, sizeof(BB), master_secret, master_len, client_random,
543  client_len, server_random, server_len, &output[16], 16) &&
544  security_premaster_hash(CCC, sizeof(CCC), master_secret, master_len, client_random,
545  client_len, server_random, server_len, &output[32],
546  out_len - 32);
547 }
548 
549 static BOOL security_X(const BYTE* master_secret, size_t master_len, const BYTE* client_random,
550  size_t client_len, const BYTE* server_random, size_t server_len,
551  BYTE* output, size_t out_len)
552 {
553  const BYTE X[] = { 'X' };
554  const BYTE YY[] = { 'Y', 'Y' };
555  const BYTE ZZZ[] = { 'Z', 'Z', 'Z' };
556 
557  WINPR_ASSERT(out_len >= 32);
558 
559  return security_premaster_hash(X, sizeof(X), master_secret, master_len, client_random,
560  client_len, server_random, server_len, &output[0], 16) &&
561  security_premaster_hash(YY, sizeof(YY), master_secret, master_len, client_random,
562  client_len, server_random, server_len, &output[16], 16) &&
563  security_premaster_hash(ZZZ, sizeof(ZZZ), master_secret, master_len, client_random,
564  client_len, server_random, server_len, &output[32],
565  out_len - 32);
566 }
567 
568 static void fips_expand_key_bits(const BYTE* in, size_t in_len, BYTE* out, size_t out_len)
569 {
570  BYTE buf[21] = { 0 };
571 
572  WINPR_ASSERT(in);
573  WINPR_ASSERT(in_len >= sizeof(buf));
574 
575  WINPR_ASSERT(out);
576  WINPR_ASSERT(out_len >= 24);
577 
578  /* reverse every byte in the key */
579  for (size_t i = 0; i < sizeof(buf); i++)
580  buf[i] = fips_reverse_table[in[i]];
581 
582  /* insert a zero-bit after every 7th bit */
583  size_t b = 0;
584  for (size_t i = 0; i < 24; i++, b += 7)
585  {
586  const size_t p = b / 8;
587  const size_t r = b % 8;
588 
589  WINPR_ASSERT(p < sizeof(buf));
590  if (r <= 1)
591  {
592  out[i] = (buf[p] << r) & 0xfe;
593  }
594  else
595  {
596  WINPR_ASSERT(p + 1 < sizeof(buf));
597  /* c is accumulator */
598  BYTE c = (BYTE)(buf[p] << r) & 0xFF;
599  c |= buf[p + 1] >> (8 - r);
600  out[i] = c & 0xfe;
601  }
602  }
603 
604  /* reverse every byte */
605  /* alter lsb so the byte has odd parity */
606  for (size_t i = 0; i < 24; i++)
607  out[i] = fips_oddparity_table[fips_reverse_table[out[i]]];
608 }
609 
610 BOOL security_establish_keys(rdpRdp* rdp)
611 {
612  BYTE pre_master_secret[48] = { 0 };
613  BYTE master_secret[48] = { 0 };
614  BYTE session_key_blob[48] = { 0 };
615  BYTE salt[] = { 0xD1, 0x26, 0x9E }; /* 40 bits: 3 bytes, 56 bits: 1 byte */
616  BOOL status = FALSE;
617 
618  WINPR_ASSERT(rdp);
619  const rdpSettings* settings = rdp->settings;
620  WINPR_ASSERT(settings);
621 
622  const BYTE* server_random = freerdp_settings_get_pointer(settings, FreeRDP_ServerRandom);
623  const BYTE* client_random = freerdp_settings_get_pointer(settings, FreeRDP_ClientRandom);
624  WINPR_ASSERT(client_random);
625  WINPR_ASSERT(server_random);
626 
627  const UINT32 ClientRandomLength =
628  freerdp_settings_get_uint32(settings, FreeRDP_ClientRandomLength);
629  const UINT32 ServerRandomLength =
630  freerdp_settings_get_uint32(settings, FreeRDP_ServerRandomLength);
631  WINPR_ASSERT(ClientRandomLength == 32);
632  WINPR_ASSERT(ServerRandomLength == 32);
633 
634  if (settings->EncryptionMethods == ENCRYPTION_METHOD_FIPS)
635  {
636  BYTE client_encrypt_key_t[WINPR_SHA1_DIGEST_LENGTH + 1] = { 0 };
637  BYTE client_decrypt_key_t[WINPR_SHA1_DIGEST_LENGTH + 1] = { 0 };
638  WINPR_DIGEST_CTX* sha1 = winpr_Digest_New();
639  if (!sha1)
640  return FALSE;
641 
642  if (!winpr_Digest_Init(sha1, WINPR_MD_SHA1) ||
643  !winpr_Digest_Update(sha1, client_random + 16, 16) ||
644  !winpr_Digest_Update(sha1, server_random + 16, 16) ||
645  !winpr_Digest_Final(sha1, client_encrypt_key_t, sizeof(client_encrypt_key_t)))
646  {
647  winpr_Digest_Free(sha1);
648  return FALSE;
649  }
650 
651  client_encrypt_key_t[20] = client_encrypt_key_t[0];
652 
653  if (!winpr_Digest_Init(sha1, WINPR_MD_SHA1) ||
654  !winpr_Digest_Update(sha1, client_random, 16) ||
655  !winpr_Digest_Update(sha1, server_random, 16) ||
656  !winpr_Digest_Final(sha1, client_decrypt_key_t, sizeof(client_decrypt_key_t)))
657  {
658  winpr_Digest_Free(sha1);
659  return FALSE;
660  }
661 
662  client_decrypt_key_t[20] = client_decrypt_key_t[0];
663 
664  if (!winpr_Digest_Init(sha1, WINPR_MD_SHA1) ||
665  !winpr_Digest_Update(sha1, client_decrypt_key_t, WINPR_SHA1_DIGEST_LENGTH) ||
666  !winpr_Digest_Update(sha1, client_encrypt_key_t, WINPR_SHA1_DIGEST_LENGTH) ||
667  !winpr_Digest_Final(sha1, rdp->fips_sign_key, WINPR_SHA1_DIGEST_LENGTH))
668  {
669  winpr_Digest_Free(sha1);
670  return FALSE;
671  }
672 
673  winpr_Digest_Free(sha1);
674 
675  if (settings->ServerMode)
676  {
677  fips_expand_key_bits(client_encrypt_key_t, sizeof(client_encrypt_key_t),
678  rdp->fips_decrypt_key, sizeof(rdp->fips_decrypt_key));
679  fips_expand_key_bits(client_decrypt_key_t, sizeof(client_decrypt_key_t),
680  rdp->fips_encrypt_key, sizeof(rdp->fips_encrypt_key));
681  }
682  else
683  {
684  fips_expand_key_bits(client_encrypt_key_t, sizeof(client_encrypt_key_t),
685  rdp->fips_encrypt_key, sizeof(rdp->fips_encrypt_key));
686  fips_expand_key_bits(client_decrypt_key_t, sizeof(client_decrypt_key_t),
687  rdp->fips_decrypt_key, sizeof(rdp->fips_decrypt_key));
688  }
689  }
690 
691  memcpy(pre_master_secret, client_random, 24);
692  memcpy(pre_master_secret + 24, server_random, 24);
693 
694  if (!security_A(pre_master_secret, sizeof(pre_master_secret), client_random, ClientRandomLength,
695  server_random, ServerRandomLength, master_secret, sizeof(master_secret)) ||
696  !security_X(master_secret, sizeof(master_secret), client_random, ClientRandomLength,
697  server_random, ServerRandomLength, session_key_blob, sizeof(session_key_blob)))
698  {
699  return FALSE;
700  }
701 
702  memcpy(rdp->sign_key, session_key_blob, 16);
703 
704  if (settings->ServerMode)
705  {
706  status = security_md5_16_32_32(&session_key_blob[16], client_random, server_random,
707  rdp->encrypt_key, sizeof(rdp->encrypt_key));
708  status &= security_md5_16_32_32(&session_key_blob[32], client_random, server_random,
709  rdp->decrypt_key, sizeof(rdp->decrypt_key));
710  }
711  else
712  {
713  /* Allow FIPS use of MD5 here, this is just used for generation of the SessionKeyBlob as
714  * described in MS-RDPELE. */
715  /* This is for RDP licensing packets which will already be encrypted under FIPS, so the use
716  * of MD5 here is not */
717  /* for sensitive data protection. */
718  status =
719  security_md5_16_32_32_Allow_FIPS(&session_key_blob[16], client_random, server_random,
720  rdp->decrypt_key, sizeof(rdp->decrypt_key));
721  status &=
722  security_md5_16_32_32_Allow_FIPS(&session_key_blob[32], client_random, server_random,
723  rdp->encrypt_key, sizeof(rdp->encrypt_key));
724  }
725 
726  if (!status)
727  return FALSE;
728 
729  if (settings->EncryptionMethods == ENCRYPTION_METHOD_40BIT)
730  {
731  memcpy(rdp->sign_key, salt, 3);
732  memcpy(rdp->decrypt_key, salt, 3);
733  memcpy(rdp->encrypt_key, salt, 3);
734  rdp->rc4_key_len = 8;
735  }
736  else if (settings->EncryptionMethods == ENCRYPTION_METHOD_56BIT)
737  {
738  memcpy(rdp->sign_key, salt, 1);
739  memcpy(rdp->decrypt_key, salt, 1);
740  memcpy(rdp->encrypt_key, salt, 1);
741  rdp->rc4_key_len = 8;
742  }
743  else if (settings->EncryptionMethods == ENCRYPTION_METHOD_128BIT)
744  {
745  rdp->rc4_key_len = 16;
746  }
747 
748  if (!security_lock(rdp))
749  return FALSE;
750  memcpy(rdp->decrypt_update_key, rdp->decrypt_key, 16);
751  memcpy(rdp->encrypt_update_key, rdp->encrypt_key, 16);
752  rdp->decrypt_use_count = 0;
753  rdp->decrypt_checksum_use_count = 0;
754  rdp->encrypt_use_count = 0;
755  rdp->encrypt_checksum_use_count = 0;
756 
757  return security_unlock(rdp);
758 }
759 
760 static BOOL security_key_update(BYTE* key, BYTE* update_key, size_t key_len, rdpRdp* rdp)
761 {
762  BYTE sha1h[WINPR_SHA1_DIGEST_LENGTH] = { 0 };
763  WINPR_DIGEST_CTX* sha1 = NULL;
764  WINPR_DIGEST_CTX* md5 = NULL;
765  WINPR_RC4_CTX* rc4 = NULL;
766  BYTE salt[] = { 0xD1, 0x26, 0x9E }; /* 40 bits: 3 bytes, 56 bits: 1 byte */
767  BOOL result = FALSE;
768  WLog_DBG(TAG, "updating RDP key");
769 
770  if (!(sha1 = winpr_Digest_New()))
771  goto out;
772 
773  if (!winpr_Digest_Init(sha1, WINPR_MD_SHA1))
774  goto out;
775 
776  if (!winpr_Digest_Update(sha1, update_key, key_len))
777  goto out;
778 
779  if (!winpr_Digest_Update(sha1, pad1, sizeof(pad1)))
780  goto out;
781 
782  if (!winpr_Digest_Update(sha1, key, key_len))
783  goto out;
784 
785  if (!winpr_Digest_Final(sha1, sha1h, sizeof(sha1h)))
786  goto out;
787 
788  if (!(md5 = winpr_Digest_New()))
789  goto out;
790 
791  if (!winpr_Digest_Init(md5, WINPR_MD_MD5))
792  goto out;
793 
794  if (!winpr_Digest_Update(md5, update_key, key_len))
795  goto out;
796 
797  if (!winpr_Digest_Update(md5, pad2, sizeof(pad2)))
798  goto out;
799 
800  if (!winpr_Digest_Update(md5, sha1h, sizeof(sha1h)))
801  goto out;
802 
803  if (!winpr_Digest_Final(md5, key, WINPR_MD5_DIGEST_LENGTH))
804  goto out;
805 
806  if (!(rc4 = winpr_RC4_New(key, key_len)))
807  goto out;
808 
809  if (!winpr_RC4_Update(rc4, key_len, key, key))
810  goto out;
811 
812  if (rdp->settings->EncryptionMethods == ENCRYPTION_METHOD_40BIT)
813  memcpy(key, salt, 3);
814  else if (rdp->settings->EncryptionMethods == ENCRYPTION_METHOD_56BIT)
815  memcpy(key, salt, 1);
816 
817  result = TRUE;
818 out:
819  winpr_Digest_Free(sha1);
820  winpr_Digest_Free(md5);
821  winpr_RC4_Free(rc4);
822  return result;
823 }
824 
825 BOOL security_encrypt(BYTE* data, size_t length, rdpRdp* rdp)
826 {
827  BOOL rc = FALSE;
828 
829  WINPR_ASSERT(rdp);
830  if (!rdp->rc4_encrypt_key)
831  {
832  WLog_ERR(TAG, "rdp->rc4_encrypt_key=%p", rdp->rc4_encrypt_key);
833  goto fail;
834  }
835 
836  if (rdp->encrypt_use_count >= 4096)
837  {
838  if (!security_key_update(rdp->encrypt_key, rdp->encrypt_update_key, rdp->rc4_key_len, rdp))
839  goto fail;
840 
841  if (!rdp_reset_rc4_encrypt_keys(rdp))
842  goto fail;
843  }
844 
845  if (!winpr_RC4_Update(rdp->rc4_encrypt_key, length, data, data))
846  goto fail;
847 
848  rdp->encrypt_use_count++;
849  rdp->encrypt_checksum_use_count++;
850  rc = TRUE;
851 fail:
852  return rc;
853 }
854 
855 BOOL security_decrypt(BYTE* data, size_t length, rdpRdp* rdp)
856 {
857  BOOL rc = FALSE;
858 
859  WINPR_ASSERT(data || (length == 0));
860  WINPR_ASSERT(rdp);
861 
862  if (!rdp->rc4_decrypt_key)
863  {
864  WLog_ERR(TAG, "rdp->rc4_decrypt_key=%p", rdp->rc4_decrypt_key);
865  goto fail;
866  }
867 
868  if (rdp->decrypt_use_count >= 4096)
869  {
870  if (!security_key_update(rdp->decrypt_key, rdp->decrypt_update_key, rdp->rc4_key_len, rdp))
871  goto fail;
872 
873  if (!rdp_reset_rc4_decrypt_keys(rdp))
874  goto fail;
875  }
876 
877  if (!winpr_RC4_Update(rdp->rc4_decrypt_key, length, data, data))
878  goto fail;
879 
880  rdp->decrypt_use_count += 1;
881  rdp->decrypt_checksum_use_count++;
882  rc = TRUE;
883 fail:
884  if (!rc)
885  WLog_WARN(TAG, "Failed to decrypt security");
886  return rc;
887 }
888 
889 BOOL security_hmac_signature(const BYTE* data, size_t length, BYTE* output, size_t out_len,
890  rdpRdp* rdp)
891 {
892  BYTE buf[WINPR_SHA1_DIGEST_LENGTH] = { 0 };
893  BYTE use_count_le[4] = { 0 };
894  WINPR_HMAC_CTX* hmac = NULL;
895  BOOL result = FALSE;
896 
897  WINPR_ASSERT(rdp);
898  WINPR_ASSERT(output);
899  WINPR_ASSERT(out_len >= 8);
900 
901  security_UINT32_le(use_count_le, sizeof(use_count_le), rdp->encrypt_use_count);
902 
903  if (!(hmac = winpr_HMAC_New()))
904  return FALSE;
905 
906  if (!winpr_HMAC_Init(hmac, WINPR_MD_SHA1, rdp->fips_sign_key, WINPR_SHA1_DIGEST_LENGTH))
907  goto out;
908 
909  if (!winpr_HMAC_Update(hmac, data, length))
910  goto out;
911 
912  if (!winpr_HMAC_Update(hmac, use_count_le, 4))
913  goto out;
914 
915  if (!winpr_HMAC_Final(hmac, buf, WINPR_SHA1_DIGEST_LENGTH))
916  goto out;
917 
918  memmove(output, buf, 8);
919  result = TRUE;
920 out:
921  winpr_HMAC_Free(hmac);
922  return result;
923 }
924 
925 BOOL security_fips_encrypt(BYTE* data, size_t length, rdpRdp* rdp)
926 {
927  BOOL rc = FALSE;
928  size_t olen = 0;
929 
930  if (!winpr_Cipher_Update(rdp->fips_encrypt, data, length, data, &olen))
931  goto fail;
932 
933  rdp->encrypt_use_count++;
934  rc = TRUE;
935 fail:
936  return rc;
937 }
938 
939 BOOL security_fips_decrypt(BYTE* data, size_t length, rdpRdp* rdp)
940 {
941  size_t olen = 0;
942 
943  if (!rdp || !rdp->fips_decrypt)
944  {
945  WLog_ERR(TAG, "rdp=%p, rdp->fips_decrypt=%p", rdp, rdp ? rdp->fips_decrypt : NULL);
946  return FALSE;
947  }
948 
949  if (!winpr_Cipher_Update(rdp->fips_decrypt, data, length, data, &olen))
950  return FALSE;
951 
952  return TRUE;
953 }
954 
955 BOOL security_fips_check_signature(const BYTE* data, size_t length, const BYTE* sig, size_t sig_len,
956  rdpRdp* rdp)
957 {
958  BYTE buf[WINPR_SHA1_DIGEST_LENGTH] = { 0 };
959  BYTE use_count_le[4] = { 0 };
960  WINPR_HMAC_CTX* hmac = NULL;
961  BOOL result = FALSE;
962 
963  security_UINT32_le(use_count_le, sizeof(use_count_le), rdp->decrypt_use_count++);
964 
965  if (!(hmac = winpr_HMAC_New()))
966  goto out;
967 
968  if (!winpr_HMAC_Init(hmac, WINPR_MD_SHA1, rdp->fips_sign_key, WINPR_SHA1_DIGEST_LENGTH))
969  goto out;
970 
971  if (!winpr_HMAC_Update(hmac, data, length))
972  goto out;
973 
974  if (!winpr_HMAC_Update(hmac, use_count_le, 4))
975  goto out;
976 
977  if (!winpr_HMAC_Final(hmac, buf, WINPR_SHA1_DIGEST_LENGTH))
978  goto out;
979 
980  if ((sig_len >= 8) && (memcmp(sig, buf, 8) == 0))
981  result = TRUE;
982 
983 out:
984  if (!result)
985  WLog_WARN(TAG, "signature check failed");
986  winpr_HMAC_Free(hmac);
987  return result;
988 }
989 
990 BOOL security_lock(rdpRdp* rdp)
991 {
992  WINPR_ASSERT(rdp);
993  EnterCriticalSection(&rdp->critical);
994  return TRUE;
995 }
996 
997 BOOL security_unlock(rdpRdp* rdp)
998 {
999  WINPR_ASSERT(rdp);
1000  LeaveCriticalSection(&rdp->critical);
1001  return TRUE;
1002 }
freerdp_settings_get_uint32
FREERDP_API UINT32 freerdp_settings_get_uint32(const rdpSettings *settings, FreeRDP_Settings_Keys_UInt32 id)
Returns a UINT32 settings value.
Definition: settings_getters.c:1613
freerdp_settings_get_pointer
FREERDP_API const void * freerdp_settings_get_pointer(const rdpSettings *settings, FreeRDP_Settings_Keys_Pointer id)
Returns a immutable pointer settings value.
Definition: common/settings.c:1321