FreeRDP
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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
31static const BYTE A[] = { 'A' };
32static const BYTE BB[] = { 'B', 'B' };
33static const BYTE CCC[] = { 'C', 'C', 'C' };
34
35/* 0x36 repeated 40 times */
36static const BYTE pad1[40] = { 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36,
37 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36,
38 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36,
39 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36 };
40
41/* 0x5C repeated 48 times */
42static const BYTE pad2[48] = { 0x5C, 0x5C, 0x5C, 0x5C, 0x5C, 0x5C, 0x5C, 0x5C, 0x5C, 0x5C,
43 0x5C, 0x5C, 0x5C, 0x5C, 0x5C, 0x5C, 0x5C, 0x5C, 0x5C, 0x5C,
44 0x5C, 0x5C, 0x5C, 0x5C, 0x5C, 0x5C, 0x5C, 0x5C, 0x5C, 0x5C,
45 0x5C, 0x5C, 0x5C, 0x5C, 0x5C, 0x5C, 0x5C, 0x5C, 0x5C, 0x5C,
46 0x5C, 0x5C, 0x5C, 0x5C, 0x5C, 0x5C, 0x5C, 0x5C };
47
48static const BYTE fips_reverse_table[256] = {
49 0x00, 0x80, 0x40, 0xc0, 0x20, 0xa0, 0x60, 0xe0, 0x10, 0x90, 0x50, 0xd0, 0x30, 0xb0, 0x70, 0xf0,
50 0x08, 0x88, 0x48, 0xc8, 0x28, 0xa8, 0x68, 0xe8, 0x18, 0x98, 0x58, 0xd8, 0x38, 0xb8, 0x78, 0xf8,
51 0x04, 0x84, 0x44, 0xc4, 0x24, 0xa4, 0x64, 0xe4, 0x14, 0x94, 0x54, 0xd4, 0x34, 0xb4, 0x74, 0xf4,
52 0x0c, 0x8c, 0x4c, 0xcc, 0x2c, 0xac, 0x6c, 0xec, 0x1c, 0x9c, 0x5c, 0xdc, 0x3c, 0xbc, 0x7c, 0xfc,
53 0x02, 0x82, 0x42, 0xc2, 0x22, 0xa2, 0x62, 0xe2, 0x12, 0x92, 0x52, 0xd2, 0x32, 0xb2, 0x72, 0xf2,
54 0x0a, 0x8a, 0x4a, 0xca, 0x2a, 0xaa, 0x6a, 0xea, 0x1a, 0x9a, 0x5a, 0xda, 0x3a, 0xba, 0x7a, 0xfa,
55 0x06, 0x86, 0x46, 0xc6, 0x26, 0xa6, 0x66, 0xe6, 0x16, 0x96, 0x56, 0xd6, 0x36, 0xb6, 0x76, 0xf6,
56 0x0e, 0x8e, 0x4e, 0xce, 0x2e, 0xae, 0x6e, 0xee, 0x1e, 0x9e, 0x5e, 0xde, 0x3e, 0xbe, 0x7e, 0xfe,
57 0x01, 0x81, 0x41, 0xc1, 0x21, 0xa1, 0x61, 0xe1, 0x11, 0x91, 0x51, 0xd1, 0x31, 0xb1, 0x71, 0xf1,
58 0x09, 0x89, 0x49, 0xc9, 0x29, 0xa9, 0x69, 0xe9, 0x19, 0x99, 0x59, 0xd9, 0x39, 0xb9, 0x79, 0xf9,
59 0x05, 0x85, 0x45, 0xc5, 0x25, 0xa5, 0x65, 0xe5, 0x15, 0x95, 0x55, 0xd5, 0x35, 0xb5, 0x75, 0xf5,
60 0x0d, 0x8d, 0x4d, 0xcd, 0x2d, 0xad, 0x6d, 0xed, 0x1d, 0x9d, 0x5d, 0xdd, 0x3d, 0xbd, 0x7d, 0xfd,
61 0x03, 0x83, 0x43, 0xc3, 0x23, 0xa3, 0x63, 0xe3, 0x13, 0x93, 0x53, 0xd3, 0x33, 0xb3, 0x73, 0xf3,
62 0x0b, 0x8b, 0x4b, 0xcb, 0x2b, 0xab, 0x6b, 0xeb, 0x1b, 0x9b, 0x5b, 0xdb, 0x3b, 0xbb, 0x7b, 0xfb,
63 0x07, 0x87, 0x47, 0xc7, 0x27, 0xa7, 0x67, 0xe7, 0x17, 0x97, 0x57, 0xd7, 0x37, 0xb7, 0x77, 0xf7,
64 0x0f, 0x8f, 0x4f, 0xcf, 0x2f, 0xaf, 0x6f, 0xef, 0x1f, 0x9f, 0x5f, 0xdf, 0x3f, 0xbf, 0x7f, 0xff
65};
66
67static const BYTE fips_oddparity_table[256] = {
68 0x01, 0x01, 0x02, 0x02, 0x04, 0x04, 0x07, 0x07, 0x08, 0x08, 0x0b, 0x0b, 0x0d, 0x0d, 0x0e, 0x0e,
69 0x10, 0x10, 0x13, 0x13, 0x15, 0x15, 0x16, 0x16, 0x19, 0x19, 0x1a, 0x1a, 0x1c, 0x1c, 0x1f, 0x1f,
70 0x20, 0x20, 0x23, 0x23, 0x25, 0x25, 0x26, 0x26, 0x29, 0x29, 0x2a, 0x2a, 0x2c, 0x2c, 0x2f, 0x2f,
71 0x31, 0x31, 0x32, 0x32, 0x34, 0x34, 0x37, 0x37, 0x38, 0x38, 0x3b, 0x3b, 0x3d, 0x3d, 0x3e, 0x3e,
72 0x40, 0x40, 0x43, 0x43, 0x45, 0x45, 0x46, 0x46, 0x49, 0x49, 0x4a, 0x4a, 0x4c, 0x4c, 0x4f, 0x4f,
73 0x51, 0x51, 0x52, 0x52, 0x54, 0x54, 0x57, 0x57, 0x58, 0x58, 0x5b, 0x5b, 0x5d, 0x5d, 0x5e, 0x5e,
74 0x61, 0x61, 0x62, 0x62, 0x64, 0x64, 0x67, 0x67, 0x68, 0x68, 0x6b, 0x6b, 0x6d, 0x6d, 0x6e, 0x6e,
75 0x70, 0x70, 0x73, 0x73, 0x75, 0x75, 0x76, 0x76, 0x79, 0x79, 0x7a, 0x7a, 0x7c, 0x7c, 0x7f, 0x7f,
76 0x80, 0x80, 0x83, 0x83, 0x85, 0x85, 0x86, 0x86, 0x89, 0x89, 0x8a, 0x8a, 0x8c, 0x8c, 0x8f, 0x8f,
77 0x91, 0x91, 0x92, 0x92, 0x94, 0x94, 0x97, 0x97, 0x98, 0x98, 0x9b, 0x9b, 0x9d, 0x9d, 0x9e, 0x9e,
78 0xa1, 0xa1, 0xa2, 0xa2, 0xa4, 0xa4, 0xa7, 0xa7, 0xa8, 0xa8, 0xab, 0xab, 0xad, 0xad, 0xae, 0xae,
79 0xb0, 0xb0, 0xb3, 0xb3, 0xb5, 0xb5, 0xb6, 0xb6, 0xb9, 0xb9, 0xba, 0xba, 0xbc, 0xbc, 0xbf, 0xbf,
80 0xc1, 0xc1, 0xc2, 0xc2, 0xc4, 0xc4, 0xc7, 0xc7, 0xc8, 0xc8, 0xcb, 0xcb, 0xcd, 0xcd, 0xce, 0xce,
81 0xd0, 0xd0, 0xd3, 0xd3, 0xd5, 0xd5, 0xd6, 0xd6, 0xd9, 0xd9, 0xda, 0xda, 0xdc, 0xdc, 0xdf, 0xdf,
82 0xe0, 0xe0, 0xe3, 0xe3, 0xe5, 0xe5, 0xe6, 0xe6, 0xe9, 0xe9, 0xea, 0xea, 0xec, 0xec, 0xef, 0xef,
83 0xf1, 0xf1, 0xf2, 0xf2, 0xf4, 0xf4, 0xf7, 0xf7, 0xf8, 0xf8, 0xfb, 0xfb, 0xfd, 0xfd, 0xfe, 0xfe
84};
85
86static BOOL security_salted_hash(const BYTE* salt, size_t salt_len, const BYTE* input,
87 size_t length, const BYTE* salt1, size_t salt1_len,
88 const BYTE* salt2, size_t salt2_len, BYTE* output, size_t out_len)
89{
90 WINPR_DIGEST_CTX* sha1 = nullptr;
91 WINPR_DIGEST_CTX* md5 = nullptr;
92 BYTE sha1_digest[WINPR_SHA1_DIGEST_LENGTH] = WINPR_C_ARRAY_INIT;
93 BOOL result = FALSE;
94
95 /* SaltedHash(Salt, Input, Salt1, Salt2) = MD5(S + SHA1(Input + Salt + Salt1 + Salt2)) */
96 WINPR_ASSERT(out_len >= WINPR_MD5_DIGEST_LENGTH);
97
98 /* SHA1_Digest = SHA1(Input + Salt + Salt1 + Salt2) */
99 if (!(sha1 = winpr_Digest_New()))
100 goto out;
101
102 if (!winpr_Digest_Init(sha1, WINPR_MD_SHA1))
103 goto out;
104
105 if (!winpr_Digest_Update(sha1, input, length)) /* Input */
106 goto out;
107
108 WINPR_ASSERT(salt_len == 48);
109 if (!winpr_Digest_Update(sha1, salt, salt_len)) /* Salt (48 bytes) */
110 goto out;
111
112 WINPR_ASSERT(salt1_len == 32);
113 if (!winpr_Digest_Update(sha1, salt1, salt1_len)) /* Salt1 (32 bytes) */
114 goto out;
115
116 WINPR_ASSERT(salt2_len == 32);
117 if (!winpr_Digest_Update(sha1, salt2, salt2_len)) /* Salt2 (32 bytes) */
118 goto out;
119
120 if (!winpr_Digest_Final(sha1, sha1_digest, sizeof(sha1_digest)))
121 goto out;
122
123 /* SaltedHash(Salt, Input, Salt1, Salt2) = MD5(S + SHA1_Digest) */
124 if (!(md5 = winpr_Digest_New()))
125 goto out;
126
127 /* Allow FIPS override for use of MD5 here, this is used for creating hashes of the
128 * premaster_secret and master_secret */
129 /* used for RDP licensing as described in MS-RDPELE. This is for RDP licensing packets */
130 /* which will already be encrypted under FIPS, so the use of MD5 here is not for sensitive data
131 * protection. */
132 if (!winpr_Digest_Init_Allow_FIPS(md5, WINPR_MD_MD5))
133 goto out;
134
135 if (!winpr_Digest_Update(md5, salt, 48)) /* Salt (48 bytes) */
136 goto out;
137
138 if (!winpr_Digest_Update(md5, sha1_digest, sizeof(sha1_digest))) /* SHA1_Digest */
139 goto out;
140
141 if (!winpr_Digest_Final(md5, output, out_len))
142 goto out;
143
144 result = TRUE;
145out:
146 winpr_Digest_Free(sha1);
147 winpr_Digest_Free(md5);
148 return result;
149}
150
151static BOOL security_premaster_hash(const BYTE* input, size_t length, const BYTE* premaster_secret,
152 size_t pre_len, const BYTE* client_random, size_t client_len,
153 const BYTE* server_random, size_t server_len, BYTE* output,
154 size_t out_len)
155{
156 /* PremasterHash(Input) = SaltedHash(PremasterSecret, Input, ClientRandom, ServerRandom) */
157 return security_salted_hash(premaster_secret, pre_len, input, length, client_random, client_len,
158 server_random, server_len, output, out_len);
159}
160
161BOOL security_master_secret(const BYTE* premaster_secret, size_t pre_len, const BYTE* client_random,
162 size_t client_len, const BYTE* server_random, size_t server_len,
163 BYTE* output, size_t out_len)
164{
165 /* MasterSecret = PremasterHash('A') + PremasterHash('BB') + PremasterHash('CCC') */
166 WINPR_ASSERT(out_len >= 32);
167 return security_premaster_hash(A, sizeof(A), premaster_secret, pre_len, client_random,
168 client_len, server_random, server_len, &output[0], out_len) &&
169 security_premaster_hash(BB, sizeof(BB), premaster_secret, pre_len, client_random,
170 client_len, server_random, server_len, &output[16],
171 out_len - 16) &&
172 security_premaster_hash(CCC, sizeof(CCC), premaster_secret, pre_len, client_random,
173 client_len, server_random, server_len, &output[32],
174 out_len - 32);
175}
176
177static BOOL security_master_hash(const BYTE* input, size_t length, const BYTE* master_secret,
178 size_t master_len, const BYTE* client_random, size_t client_len,
179 const BYTE* server_random, size_t server_len, BYTE* output,
180 size_t out_len)
181{
182 /* MasterHash(Input) = SaltedHash(MasterSecret, Input, ServerRandom, ClientRandom) */
183 return security_salted_hash(master_secret, master_len, input, length, server_random, server_len,
184 client_random, client_len, output, out_len);
185}
186
187BOOL security_session_key_blob(const BYTE* master_secret, size_t master_len,
188 const BYTE* client_random, size_t client_len,
189 const BYTE* server_random, size_t server_len, BYTE* output,
190 size_t out_len)
191{
192 /* MasterHash = MasterHash('A') + MasterHash('BB') + MasterHash('CCC') */
193 WINPR_ASSERT(out_len >= 32);
194 return security_master_hash(A, sizeof(A), master_secret, master_len, client_random, client_len,
195 server_random, server_len, &output[0], 16) &&
196 security_master_hash(BB, sizeof(BB), master_secret, master_len, client_random,
197 client_len, server_random, server_len, &output[16], 16) &&
198 security_master_hash(CCC, sizeof(CCC), master_secret, master_len, client_random,
199 client_len, server_random, server_len, &output[32], out_len - 32);
200}
201
202void security_mac_salt_key(const BYTE* session_key_blob, WINPR_ATTR_UNUSED size_t session_len,
203 WINPR_ATTR_UNUSED const BYTE* client_random,
204 WINPR_ATTR_UNUSED size_t client_len,
205 WINPR_ATTR_UNUSED const BYTE* server_random,
206 WINPR_ATTR_UNUSED size_t server_len, BYTE* output,
207 WINPR_ATTR_UNUSED size_t out_len)
208{
209 /* MacSaltKey = First128Bits(SessionKeyBlob) */
210 WINPR_ASSERT(out_len >= 16);
211 WINPR_ASSERT(session_len >= 16);
212 memcpy(output, session_key_blob, 16);
213}
214
215static BOOL security_md5_16_32_32(const BYTE* in0, const BYTE* in1, const BYTE* in2, BYTE* output,
216 size_t out_len)
217{
218 WINPR_DIGEST_CTX* md5 = nullptr;
219 BOOL result = FALSE;
220
221 WINPR_ASSERT(WINPR_MD5_DIGEST_LENGTH <= out_len);
222
223 if (!(md5 = winpr_Digest_New()))
224 return FALSE;
225
226 if (!winpr_Digest_Init(md5, WINPR_MD_MD5))
227 goto out;
228
229 if (!winpr_Digest_Update(md5, in0, 16))
230 goto out;
231
232 if (!winpr_Digest_Update(md5, in1, 32))
233 goto out;
234
235 if (!winpr_Digest_Update(md5, in2, 32))
236 goto out;
237
238 if (!winpr_Digest_Final(md5, output, out_len))
239 goto out;
240
241 result = TRUE;
242out:
243 winpr_Digest_Free(md5);
244 return result;
245}
246
247static BOOL security_md5_16_32_32_Allow_FIPS(const BYTE* in0, const BYTE* in1, const BYTE* in2,
248 BYTE* output, size_t out_len)
249{
250 WINPR_DIGEST_CTX* md5 = nullptr;
251 BOOL result = FALSE;
252
253 WINPR_ASSERT(out_len >= WINPR_MD5_DIGEST_LENGTH);
254
255 if (!(md5 = winpr_Digest_New()))
256 return FALSE;
257 if (!winpr_Digest_Init_Allow_FIPS(md5, WINPR_MD_MD5))
258 goto out;
259 if (!winpr_Digest_Update(md5, in0, 16))
260 goto out;
261 if (!winpr_Digest_Update(md5, in1, 32))
262 goto out;
263 if (!winpr_Digest_Update(md5, in2, 32))
264 goto out;
265 if (!winpr_Digest_Final(md5, output, out_len))
266 goto out;
267
268 result = TRUE;
269out:
270 winpr_Digest_Free(md5);
271 return result;
272}
273
274BOOL security_licensing_encryption_key(const BYTE* session_key_blob, size_t session_len,
275 const BYTE* client_random, size_t client_len,
276 const BYTE* server_random, size_t server_len, BYTE* output,
277 size_t out_len)
278{
279 if (session_len < 16)
280 return FALSE;
281 if (client_len < 32)
282 return FALSE;
283 if (server_len < 32)
284 return FALSE;
285 /* LicensingEncryptionKey = MD5(Second128Bits(SessionKeyBlob) + ClientRandom + ServerRandom))
286 * Allow FIPS use of MD5 here, this is just used for creating the licensing encryption key as
287 * described in MS-RDPELE. This is for RDP licensing packets which will already be encrypted
288 * under FIPS, so the use of MD5 here is not for sensitive data protection. */
289 return security_md5_16_32_32_Allow_FIPS(&session_key_blob[16], client_random, server_random,
290 output, out_len);
291}
292
293static void security_UINT32_le(BYTE* output, WINPR_ATTR_UNUSED size_t out_len, UINT32 value)
294{
295 WINPR_ASSERT(output);
296 WINPR_ASSERT(out_len >= 4);
297 output[0] = (value)&0xFF;
298 output[1] = (value >> 8) & 0xFF;
299 output[2] = (value >> 16) & 0xFF;
300 output[3] = (value >> 24) & 0xFF;
301}
302
303BOOL security_mac_data(const BYTE* mac_salt_key, size_t mac_salt_key_length, const BYTE* data,
304 size_t length, BYTE* output, size_t output_length)
305{
306 WINPR_DIGEST_CTX* sha1 = nullptr;
307 WINPR_DIGEST_CTX* md5 = nullptr;
308 BYTE length_le[4] = WINPR_C_ARRAY_INIT;
309 BYTE sha1_digest[WINPR_SHA1_DIGEST_LENGTH] = WINPR_C_ARRAY_INIT;
310 BOOL result = FALSE;
311
312 WINPR_ASSERT(length <= UINT32_MAX);
313 WINPR_ASSERT(mac_salt_key_length == WINPR_MD5_DIGEST_LENGTH);
314 WINPR_ASSERT(output_length == WINPR_MD5_DIGEST_LENGTH);
315
316 /* MacData = MD5(MacSaltKey + pad2 + SHA1(MacSaltKey + pad1 + length + data)) */
317 security_UINT32_le(length_le, sizeof(length_le),
318 (UINT32)length); /* length must be little-endian */
319
320 /* SHA1_Digest = SHA1(MacSaltKey + pad1 + length + data) */
321 if (!(sha1 = winpr_Digest_New()))
322 goto out;
323
324 if (!winpr_Digest_Init(sha1, WINPR_MD_SHA1))
325 goto out;
326
327 if (!winpr_Digest_Update(sha1, mac_salt_key, mac_salt_key_length)) /* MacSaltKey */
328 goto out;
329
330 if (!winpr_Digest_Update(sha1, pad1, sizeof(pad1))) /* pad1 */
331 goto out;
332
333 if (!winpr_Digest_Update(sha1, length_le, sizeof(length_le))) /* length */
334 goto out;
335
336 if (!winpr_Digest_Update(sha1, data, length)) /* data */
337 goto out;
338
339 if (!winpr_Digest_Final(sha1, sha1_digest, sizeof(sha1_digest)))
340 goto out;
341
342 /* MacData = MD5(MacSaltKey + pad2 + SHA1_Digest) */
343 if (!(md5 = winpr_Digest_New()))
344 goto out;
345
346 /* Allow FIPS override for use of MD5 here, this is only used for creating the MACData field of
347 * the */
348 /* Client Platform Challenge Response packet (from MS-RDPELE section 2.2.2.5). This is for RDP
349 * licensing packets */
350 /* which will already be encrypted under FIPS, so the use of MD5 here is not for sensitive data
351 * protection. */
352 if (!winpr_Digest_Init_Allow_FIPS(md5, WINPR_MD_MD5))
353 goto out;
354
355 if (!winpr_Digest_Update(md5, mac_salt_key, 16)) /* MacSaltKey */
356 goto out;
357
358 if (!winpr_Digest_Update(md5, pad2, sizeof(pad2))) /* pad2 */
359 goto out;
360
361 if (!winpr_Digest_Update(md5, sha1_digest, sizeof(sha1_digest))) /* SHA1_Digest */
362 goto out;
363
364 if (!winpr_Digest_Final(md5, output, output_length))
365 goto out;
366
367 result = TRUE;
368out:
369 if (!result)
370 WLog_ERR(TAG, "failed to create security mac");
371 winpr_Digest_Free(sha1);
372 winpr_Digest_Free(md5);
373 return result;
374}
375
376BOOL security_mac_signature(rdpRdp* rdp, const BYTE* data, UINT32 length, BYTE* output,
377 size_t out_len)
378{
379 WINPR_DIGEST_CTX* sha1 = nullptr;
380 WINPR_DIGEST_CTX* md5 = nullptr;
381 BYTE length_le[4] = WINPR_C_ARRAY_INIT;
382 BYTE md5_digest[WINPR_MD5_DIGEST_LENGTH] = WINPR_C_ARRAY_INIT;
383 BYTE sha1_digest[WINPR_SHA1_DIGEST_LENGTH] = WINPR_C_ARRAY_INIT;
384 BOOL result = FALSE;
385
386 WINPR_ASSERT(rdp);
387 WINPR_ASSERT(data || (length == 0));
388 WINPR_ASSERT(output);
389 WINPR_ASSERT(out_len >= 8);
390 if (out_len < 8)
391 return FALSE;
392
393 security_UINT32_le(length_le, sizeof(length_le), length); /* length must be little-endian */
394
395 /* SHA1_Digest = SHA1(MACKeyN + pad1 + length + data) */
396 if (!(sha1 = winpr_Digest_New()))
397 goto out;
398
399 if (!winpr_Digest_Init(sha1, WINPR_MD_SHA1))
400 goto out;
401
402 WINPR_ASSERT(rdp->rc4_key_len <= sizeof(rdp->sign_key));
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 WINPR_ASSERT(rdp->rc4_key_len <= sizeof(rdp->sign_key));
426 if (!winpr_Digest_Update(md5, rdp->sign_key, rdp->rc4_key_len)) /* MacKeyN */
427 goto out;
428
429 if (!winpr_Digest_Update(md5, pad2, sizeof(pad2))) /* pad2 */
430 goto out;
431
432 if (!winpr_Digest_Update(md5, sha1_digest, sizeof(sha1_digest))) /* SHA1_Digest */
433 goto out;
434
435 if (!winpr_Digest_Final(md5, md5_digest, sizeof(md5_digest)))
436 goto out;
437
438 memcpy(output, md5_digest, 8);
439 result = TRUE;
440out:
441 if (!result)
442 WLog_WARN(TAG, "security mac generation failed");
443 winpr_Digest_Free(sha1);
444 winpr_Digest_Free(md5);
445 return result;
446}
447
448BOOL security_salted_mac_signature(rdpRdp* rdp, const BYTE* data, UINT32 length, BOOL encryption,
449 BYTE* output, size_t out_len)
450{
451 WINPR_DIGEST_CTX* sha1 = nullptr;
452 WINPR_DIGEST_CTX* md5 = nullptr;
453 BYTE length_le[4] = WINPR_C_ARRAY_INIT;
454 BYTE use_count_le[4] = WINPR_C_ARRAY_INIT;
455 BYTE md5_digest[WINPR_MD5_DIGEST_LENGTH] = WINPR_C_ARRAY_INIT;
456 BYTE sha1_digest[WINPR_SHA1_DIGEST_LENGTH] = WINPR_C_ARRAY_INIT;
457 BOOL result = FALSE;
458
459 WINPR_ASSERT(rdp);
460 WINPR_ASSERT(data || (length == 0));
461 WINPR_ASSERT(output);
462 WINPR_ASSERT(out_len >= 8);
463 if (out_len < 8)
464 return FALSE;
465
466 security_UINT32_le(length_le, sizeof(length_le), length); /* length must be little-endian */
467
468 if (encryption)
469 {
470 security_UINT32_le(use_count_le, sizeof(use_count_le), rdp->encrypt_checksum_use_count);
471 }
472 else
473 {
474 /*
475 * We calculate checksum on plain text, so we must have already
476 * decrypt it, which means decrypt_checksum_use_count is off by one.
477 */
478 security_UINT32_le(use_count_le, sizeof(use_count_le),
479 rdp->decrypt_checksum_use_count - 1u);
480 }
481
482 /* SHA1_Digest = SHA1(MACKeyN + pad1 + length + data) */
483 if (!(sha1 = winpr_Digest_New()))
484 goto out;
485
486 if (!winpr_Digest_Init(sha1, WINPR_MD_SHA1))
487 goto out;
488
489 WINPR_ASSERT(rdp->rc4_key_len <= sizeof(rdp->sign_key));
490 if (!winpr_Digest_Update(sha1, rdp->sign_key, rdp->rc4_key_len)) /* MacKeyN */
491 goto out;
492
493 if (!winpr_Digest_Update(sha1, pad1, sizeof(pad1))) /* pad1 */
494 goto out;
495
496 if (!winpr_Digest_Update(sha1, length_le, sizeof(length_le))) /* length */
497 goto out;
498
499 if (!winpr_Digest_Update(sha1, data, length)) /* data */
500 goto out;
501
502 if (!winpr_Digest_Update(sha1, use_count_le, sizeof(use_count_le))) /* encryptionCount */
503 goto out;
504
505 if (!winpr_Digest_Final(sha1, sha1_digest, sizeof(sha1_digest)))
506 goto out;
507
508 /* MACSignature = First64Bits(MD5(MACKeyN + pad2 + SHA1_Digest)) */
509 if (!(md5 = winpr_Digest_New()))
510 goto out;
511
512 if (!winpr_Digest_Init(md5, WINPR_MD_MD5))
513 goto out;
514
515 WINPR_ASSERT(rdp->rc4_key_len <= sizeof(rdp->sign_key));
516 if (!winpr_Digest_Update(md5, rdp->sign_key, rdp->rc4_key_len)) /* MacKeyN */
517 goto out;
518
519 if (!winpr_Digest_Update(md5, pad2, sizeof(pad2))) /* pad2 */
520 goto out;
521
522 if (!winpr_Digest_Update(md5, sha1_digest, sizeof(sha1_digest))) /* SHA1_Digest */
523 goto out;
524
525 if (!winpr_Digest_Final(md5, md5_digest, sizeof(md5_digest)))
526 goto out;
527
528 memcpy(output, md5_digest, 8);
529 result = TRUE;
530out:
531 if (!result)
532 WLog_WARN(TAG, "security mac signature generation failed");
533
534 winpr_Digest_Free(sha1);
535 winpr_Digest_Free(md5);
536 return result;
537}
538
539static BOOL security_A(const BYTE* master_secret, size_t master_len, const BYTE* client_random,
540 size_t client_len, const BYTE* server_random, size_t server_len,
541 BYTE* output, size_t out_len)
542{
543 WINPR_ASSERT(out_len >= 32);
544
545 return security_premaster_hash(A, sizeof(A), master_secret, master_len, client_random,
546 client_len, server_random, server_len, &output[0], 16) &&
547 security_premaster_hash(BB, sizeof(BB), master_secret, master_len, client_random,
548 client_len, server_random, server_len, &output[16], 16) &&
549 security_premaster_hash(CCC, sizeof(CCC), master_secret, master_len, client_random,
550 client_len, server_random, server_len, &output[32],
551 out_len - 32);
552}
553
554static BOOL security_X(const BYTE* master_secret, size_t master_len, const BYTE* client_random,
555 size_t client_len, const BYTE* server_random, size_t server_len,
556 BYTE* output, size_t out_len)
557{
558 const BYTE X[] = { 'X' };
559 const BYTE YY[] = { 'Y', 'Y' };
560 const BYTE ZZZ[] = { 'Z', 'Z', 'Z' };
561
562 WINPR_ASSERT(out_len >= 32);
563
564 return security_premaster_hash(X, sizeof(X), master_secret, master_len, client_random,
565 client_len, server_random, server_len, &output[0], 16) &&
566 security_premaster_hash(YY, sizeof(YY), master_secret, master_len, client_random,
567 client_len, server_random, server_len, &output[16], 16) &&
568 security_premaster_hash(ZZZ, sizeof(ZZZ), master_secret, master_len, client_random,
569 client_len, server_random, server_len, &output[32],
570 out_len - 32);
571}
572
573static void fips_expand_key_bits(const BYTE* in, WINPR_ATTR_UNUSED size_t in_len, BYTE* out,
574 WINPR_ATTR_UNUSED size_t out_len)
575{
576 BYTE buf[21] = WINPR_C_ARRAY_INIT;
577
578 WINPR_ASSERT(in);
579 WINPR_ASSERT(in_len >= sizeof(buf));
580
581 WINPR_ASSERT(out);
582 WINPR_ASSERT(out_len >= 24);
583
584 /* reverse every byte in the key */
585 for (size_t i = 0; i < sizeof(buf); i++)
586 buf[i] = fips_reverse_table[in[i]];
587
588 /* insert a zero-bit after every 7th bit */
589 size_t b = 0;
590 for (size_t i = 0; i < 24; i++, b += 7)
591 {
592 const size_t p = b / 8;
593 const size_t r = b % 8;
594
595 WINPR_ASSERT(p < sizeof(buf));
596 if (r <= 1)
597 {
598 out[i] = (buf[p] << r) & 0xfe;
599 }
600 else
601 {
602 WINPR_ASSERT(p + 1 < sizeof(buf));
603 /* c is accumulator */
604 BYTE c = (BYTE)(buf[p] << r) & 0xFF;
605 c |= buf[p + 1] >> (8 - r);
606 out[i] = c & 0xfe;
607 }
608 }
609
610 /* reverse every byte */
611 /* alter lsb so the byte has odd parity */
612 for (size_t i = 0; i < 24; i++)
613 out[i] = fips_oddparity_table[fips_reverse_table[out[i]]];
614}
615
616BOOL security_establish_keys(rdpRdp* rdp)
617{
618 BYTE pre_master_secret[48] = WINPR_C_ARRAY_INIT;
619 BYTE master_secret[48] = WINPR_C_ARRAY_INIT;
620 BYTE session_key_blob[48] = WINPR_C_ARRAY_INIT;
621 BYTE salt[] = { 0xD1, 0x26, 0x9E }; /* 40 bits: 3 bytes, 56 bits: 1 byte */
622 BOOL status = FALSE;
623
624 WINPR_ASSERT(rdp);
625 const rdpSettings* settings = rdp->settings;
626 WINPR_ASSERT(settings);
627
628 const BYTE* server_random = freerdp_settings_get_pointer(settings, FreeRDP_ServerRandom);
629 const BYTE* client_random = freerdp_settings_get_pointer(settings, FreeRDP_ClientRandom);
630 WINPR_ASSERT(client_random);
631 WINPR_ASSERT(server_random);
632
633 const UINT32 ClientRandomLength =
634 freerdp_settings_get_uint32(settings, FreeRDP_ClientRandomLength);
635 const UINT32 ServerRandomLength =
636 freerdp_settings_get_uint32(settings, FreeRDP_ServerRandomLength);
637 /* The server random is peer supplied (gcc_read_server_security_data rejects only a length
638 * of 0) while both randoms are consumed below as fixed 32 byte values, so a shorter buffer
639 * would be read past its end. WINPR_ASSERT is compiled out in release builds, enforce the
640 * length at runtime. */
641 if ((ClientRandomLength != 32) || (ServerRandomLength != 32))
642 {
643 WLog_ERR(TAG, "invalid client (%" PRIu32 ") or server (%" PRIu32 ") random length",
644 ClientRandomLength, ServerRandomLength);
645 return FALSE;
646 }
647
648 if (settings->EncryptionMethods == ENCRYPTION_METHOD_FIPS)
649 {
650 BYTE client_encrypt_key_t[WINPR_SHA1_DIGEST_LENGTH + 1] = WINPR_C_ARRAY_INIT;
651 BYTE client_decrypt_key_t[WINPR_SHA1_DIGEST_LENGTH + 1] = WINPR_C_ARRAY_INIT;
652 WINPR_DIGEST_CTX* sha1 = winpr_Digest_New();
653 if (!sha1)
654 return FALSE;
655
656 if (!winpr_Digest_Init(sha1, WINPR_MD_SHA1) ||
657 !winpr_Digest_Update(sha1, client_random + 16, 16) ||
658 !winpr_Digest_Update(sha1, server_random + 16, 16) ||
659 !winpr_Digest_Final(sha1, client_encrypt_key_t, sizeof(client_encrypt_key_t)))
660 {
661 winpr_Digest_Free(sha1);
662 return FALSE;
663 }
664
665 client_encrypt_key_t[20] = client_encrypt_key_t[0];
666
667 if (!winpr_Digest_Init(sha1, WINPR_MD_SHA1) ||
668 !winpr_Digest_Update(sha1, client_random, 16) ||
669 !winpr_Digest_Update(sha1, server_random, 16) ||
670 !winpr_Digest_Final(sha1, client_decrypt_key_t, sizeof(client_decrypt_key_t)))
671 {
672 winpr_Digest_Free(sha1);
673 return FALSE;
674 }
675
676 client_decrypt_key_t[20] = client_decrypt_key_t[0];
677
678 if (!winpr_Digest_Init(sha1, WINPR_MD_SHA1) ||
679 !winpr_Digest_Update(sha1, client_decrypt_key_t, WINPR_SHA1_DIGEST_LENGTH) ||
680 !winpr_Digest_Update(sha1, client_encrypt_key_t, WINPR_SHA1_DIGEST_LENGTH) ||
681 !winpr_Digest_Final(sha1, rdp->fips_sign_key, WINPR_SHA1_DIGEST_LENGTH))
682 {
683 winpr_Digest_Free(sha1);
684 return FALSE;
685 }
686
687 winpr_Digest_Free(sha1);
688
689 if (settings->ServerMode)
690 {
691 fips_expand_key_bits(client_encrypt_key_t, sizeof(client_encrypt_key_t),
692 rdp->fips_decrypt_key, sizeof(rdp->fips_decrypt_key));
693 fips_expand_key_bits(client_decrypt_key_t, sizeof(client_decrypt_key_t),
694 rdp->fips_encrypt_key, sizeof(rdp->fips_encrypt_key));
695 }
696 else
697 {
698 fips_expand_key_bits(client_encrypt_key_t, sizeof(client_encrypt_key_t),
699 rdp->fips_encrypt_key, sizeof(rdp->fips_encrypt_key));
700 fips_expand_key_bits(client_decrypt_key_t, sizeof(client_decrypt_key_t),
701 rdp->fips_decrypt_key, sizeof(rdp->fips_decrypt_key));
702 }
703 }
704
705 memcpy(pre_master_secret, client_random, 24);
706 memcpy(pre_master_secret + 24, server_random, 24);
707
708 if (!security_A(pre_master_secret, sizeof(pre_master_secret), client_random, ClientRandomLength,
709 server_random, ServerRandomLength, master_secret, sizeof(master_secret)) ||
710 !security_X(master_secret, sizeof(master_secret), client_random, ClientRandomLength,
711 server_random, ServerRandomLength, session_key_blob, sizeof(session_key_blob)))
712 {
713 return FALSE;
714 }
715
716 memcpy(rdp->sign_key, session_key_blob, 16);
717
718 if (settings->ServerMode)
719 {
720 status = security_md5_16_32_32(&session_key_blob[16], client_random, server_random,
721 rdp->encrypt_key, sizeof(rdp->encrypt_key));
722 status &= security_md5_16_32_32(&session_key_blob[32], client_random, server_random,
723 rdp->decrypt_key, sizeof(rdp->decrypt_key));
724 }
725 else
726 {
727 /* Allow FIPS use of MD5 here, this is just used for generation of the SessionKeyBlob as
728 * described in MS-RDPELE. */
729 /* This is for RDP licensing packets which will already be encrypted under FIPS, so the use
730 * of MD5 here is not */
731 /* for sensitive data protection. */
732 status =
733 security_md5_16_32_32_Allow_FIPS(&session_key_blob[16], client_random, server_random,
734 rdp->decrypt_key, sizeof(rdp->decrypt_key));
735 status &=
736 security_md5_16_32_32_Allow_FIPS(&session_key_blob[32], client_random, server_random,
737 rdp->encrypt_key, sizeof(rdp->encrypt_key));
738 }
739
740 if (!status)
741 return FALSE;
742
743 if (settings->EncryptionMethods == ENCRYPTION_METHOD_40BIT)
744 {
745 memcpy(rdp->sign_key, salt, 3);
746 memcpy(rdp->decrypt_key, salt, 3);
747 memcpy(rdp->encrypt_key, salt, 3);
748 rdp->rc4_key_len = 8;
749 }
750 else if (settings->EncryptionMethods == ENCRYPTION_METHOD_56BIT)
751 {
752 memcpy(rdp->sign_key, salt, 1);
753 memcpy(rdp->decrypt_key, salt, 1);
754 memcpy(rdp->encrypt_key, salt, 1);
755 rdp->rc4_key_len = 8;
756 }
757 else if (settings->EncryptionMethods == ENCRYPTION_METHOD_128BIT)
758 {
759 rdp->rc4_key_len = 16;
760 }
761
762 security_lock(rdp);
763 memcpy(rdp->decrypt_update_key, rdp->decrypt_key, 16);
764 memcpy(rdp->encrypt_update_key, rdp->encrypt_key, 16);
765 rdp->decrypt_use_count = 0;
766 rdp->decrypt_checksum_use_count = 0;
767 rdp->encrypt_use_count = 0;
768 rdp->encrypt_checksum_use_count = 0;
769
770 security_unlock(rdp);
771 return TRUE;
772}
773
774static BOOL security_key_update(BYTE* key, BYTE* update_key, size_t key_len, rdpRdp* rdp)
775{
776 BYTE sha1h[WINPR_SHA1_DIGEST_LENGTH] = WINPR_C_ARRAY_INIT;
777 WINPR_DIGEST_CTX* sha1 = nullptr;
778 WINPR_DIGEST_CTX* md5 = nullptr;
779 WINPR_RC4_CTX* rc4 = nullptr;
780 BYTE salt[] = { 0xD1, 0x26, 0x9E }; /* 40 bits: 3 bytes, 56 bits: 1 byte */
781 BOOL result = FALSE;
782 WLog_DBG(TAG, "updating RDP key");
783
784 if (!(sha1 = winpr_Digest_New()))
785 goto out;
786
787 if (!winpr_Digest_Init(sha1, WINPR_MD_SHA1))
788 goto out;
789
790 if (!winpr_Digest_Update(sha1, update_key, key_len))
791 goto out;
792
793 if (!winpr_Digest_Update(sha1, pad1, sizeof(pad1)))
794 goto out;
795
796 if (!winpr_Digest_Update(sha1, key, key_len))
797 goto out;
798
799 if (!winpr_Digest_Final(sha1, sha1h, sizeof(sha1h)))
800 goto out;
801
802 if (!(md5 = winpr_Digest_New()))
803 goto out;
804
805 if (!winpr_Digest_Init(md5, WINPR_MD_MD5))
806 goto out;
807
808 if (!winpr_Digest_Update(md5, update_key, key_len))
809 goto out;
810
811 if (!winpr_Digest_Update(md5, pad2, sizeof(pad2)))
812 goto out;
813
814 if (!winpr_Digest_Update(md5, sha1h, sizeof(sha1h)))
815 goto out;
816
817 if (!winpr_Digest_Final(md5, key, WINPR_MD5_DIGEST_LENGTH))
818 goto out;
819
820 if (!(rc4 = winpr_RC4_New(key, key_len)))
821 goto out;
822
823 if (!winpr_RC4_Update(rc4, key_len, key, key))
824 goto out;
825
826 if (rdp->settings->EncryptionMethods == ENCRYPTION_METHOD_40BIT)
827 memcpy(key, salt, 3);
828 else if (rdp->settings->EncryptionMethods == ENCRYPTION_METHOD_56BIT)
829 memcpy(key, salt, 1);
830
831 result = TRUE;
832out:
833 winpr_Digest_Free(sha1);
834 winpr_Digest_Free(md5);
835 winpr_RC4_Free(rc4);
836 return result;
837}
838
839BOOL security_encrypt(BYTE* data, size_t length, rdpRdp* rdp)
840{
841 BOOL rc = FALSE;
842
843 WINPR_ASSERT(rdp);
844 if (!rdp->rc4_encrypt_key)
845 {
846 WLog_ERR(TAG, "rdp->rc4_encrypt_key=nullptr");
847 goto fail;
848 }
849
850 if (rdp->encrypt_use_count >= 4096)
851 {
852 WINPR_ASSERT(rdp->rc4_key_len <= sizeof(rdp->encrypt_update_key));
853 if (!security_key_update(rdp->encrypt_key, rdp->encrypt_update_key, rdp->rc4_key_len, rdp))
854 goto fail;
855
856 if (!rdp_reset_rc4_encrypt_keys(rdp))
857 goto fail;
858 }
859
860 if (!winpr_RC4_Update(rdp->rc4_encrypt_key, length, data, data))
861 goto fail;
862
863 rdp->encrypt_use_count++;
864 rdp->encrypt_checksum_use_count++;
865 rc = TRUE;
866fail:
867 return rc;
868}
869
870BOOL security_decrypt(BYTE* data, size_t length, rdpRdp* rdp)
871{
872 BOOL rc = FALSE;
873
874 WINPR_ASSERT(data || (length == 0));
875 WINPR_ASSERT(rdp);
876
877 if (!rdp->rc4_decrypt_key)
878 {
879 WLog_ERR(TAG, "rdp->rc4_decrypt_key=nullptr");
880 goto fail;
881 }
882
883 if (rdp->decrypt_use_count >= 4096)
884 {
885 WINPR_ASSERT(rdp->rc4_key_len <= sizeof(rdp->encrypt_update_key));
886 if (!security_key_update(rdp->decrypt_key, rdp->decrypt_update_key, rdp->rc4_key_len, rdp))
887 goto fail;
888
889 if (!rdp_reset_rc4_decrypt_keys(rdp))
890 goto fail;
891 }
892
893 if (!winpr_RC4_Update(rdp->rc4_decrypt_key, length, data, data))
894 goto fail;
895
896 rdp->decrypt_use_count += 1;
897 rdp->decrypt_checksum_use_count++;
898 rc = TRUE;
899fail:
900 if (!rc)
901 WLog_WARN(TAG, "Failed to decrypt security");
902 return rc;
903}
904
905BOOL security_hmac_signature(const BYTE* data, size_t length, BYTE* output, size_t out_len,
906 rdpRdp* rdp)
907{
908 BYTE buf[WINPR_SHA1_DIGEST_LENGTH] = WINPR_C_ARRAY_INIT;
909 BYTE use_count_le[4] = WINPR_C_ARRAY_INIT;
910 WINPR_HMAC_CTX* hmac = nullptr;
911 BOOL result = FALSE;
912
913 WINPR_ASSERT(rdp);
914 WINPR_ASSERT(output);
915 if (out_len < 8)
916 return FALSE;
917
918 security_UINT32_le(use_count_le, sizeof(use_count_le), rdp->encrypt_use_count);
919
920 if (!(hmac = winpr_HMAC_New()))
921 return FALSE;
922
923 if (!winpr_HMAC_Init(hmac, WINPR_MD_SHA1, rdp->fips_sign_key, WINPR_SHA1_DIGEST_LENGTH))
924 goto out;
925
926 if (!winpr_HMAC_Update(hmac, data, length))
927 goto out;
928
929 if (!winpr_HMAC_Update(hmac, use_count_le, 4))
930 goto out;
931
932 if (!winpr_HMAC_Final(hmac, buf, WINPR_SHA1_DIGEST_LENGTH))
933 goto out;
934
935 memmove(output, buf, 8);
936 result = TRUE;
937out:
938 winpr_HMAC_Free(hmac);
939 return result;
940}
941
942BOOL security_fips_encrypt(BYTE* data, size_t length, rdpRdp* rdp)
943{
944 BOOL rc = FALSE;
945 size_t olen = 0;
946
947 if (!winpr_Cipher_Update(rdp->fips_encrypt, data, length, data, &olen))
948 goto fail;
949
950 rdp->encrypt_use_count++;
951 rc = TRUE;
952fail:
953 return rc;
954}
955
956BOOL security_fips_decrypt(BYTE* data, size_t length, rdpRdp* rdp)
957{
958 size_t olen = 0;
959
960 if (!rdp || !rdp->fips_decrypt)
961 {
962 WLog_ERR(TAG, "rdp=%p, rdp->fips_decrypt=%p", WINPR_CXX_COMPAT_CAST(const void*, rdp),
963 WINPR_CXX_COMPAT_CAST(const void*, rdp ? rdp->fips_decrypt : nullptr));
964 return FALSE;
965 }
966
967 if (!winpr_Cipher_Update(rdp->fips_decrypt, data, length, data, &olen))
968 return FALSE;
969
970 return TRUE;
971}
972
973BOOL security_fips_check_signature(const BYTE* data, size_t length, const BYTE* sig, size_t sig_len,
974 rdpRdp* rdp)
975{
976 BYTE buf[WINPR_SHA1_DIGEST_LENGTH] = WINPR_C_ARRAY_INIT;
977 BYTE use_count_le[4] = WINPR_C_ARRAY_INIT;
978 WINPR_HMAC_CTX* hmac = nullptr;
979 BOOL result = FALSE;
980
981 security_UINT32_le(use_count_le, sizeof(use_count_le), rdp->decrypt_use_count++);
982
983 if (!(hmac = winpr_HMAC_New()))
984 goto out;
985
986 if (!winpr_HMAC_Init(hmac, WINPR_MD_SHA1, rdp->fips_sign_key, WINPR_SHA1_DIGEST_LENGTH))
987 goto out;
988
989 if (!winpr_HMAC_Update(hmac, data, length))
990 goto out;
991
992 if (!winpr_HMAC_Update(hmac, use_count_le, 4))
993 goto out;
994
995 if (!winpr_HMAC_Final(hmac, buf, WINPR_SHA1_DIGEST_LENGTH))
996 goto out;
997
998 if ((sig_len >= 8) && (memcmp(sig, buf, 8) == 0))
999 result = TRUE;
1000
1001out:
1002 if (!result)
1003 WLog_WARN(TAG, "signature check failed");
1004 winpr_HMAC_Free(hmac);
1005 return result;
1006}
1007
1008void security_lock(rdpRdp* rdp)
1009{
1010 WINPR_ASSERT(rdp);
1011 EnterCriticalSection(&rdp->critical);
1012}
1013
1014void security_unlock(rdpRdp* rdp)
1015{
1016 WINPR_ASSERT(rdp);
1017 LeaveCriticalSection(&rdp->critical);
1018}
freerdp_settings_get_pointer
WINPR_ATTR_NODISCARD 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:1420
freerdp_settings_get_uint32
WINPR_ATTR_NODISCARD FREERDP_API UINT32 freerdp_settings_get_uint32(const rdpSettings *settings, FreeRDP_Settings_Keys_UInt32 id)
Returns a UINT32 settings value.