8be5ead1b0500a1adf12d4b8990dcf2926fe14ff
[strongswan.git] / src / libpts / pts / pts.c
1 /*
2 * Copyright (C) 2011 Sansar Choinyambuu
3 * HSR Hochschule fuer Technik Rapperswil
4 *
5 * This program is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License as published by the
7 * Free Software Foundation; either version 2 of the License, or (at your
8 * option) any later version. See <http://www.fsf.org/copyleft/gpl.txt>.
9 *
10 * This program is distributed in the hope that it will be useful, but
11 * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
12 * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
13 * for more details.
14 */
15
16 #include "pts.h"
17
18 #include <debug.h>
19 #include <crypto/hashers/hasher.h>
20
21 #include <trousers/tss.h>
22 #include <trousers/trousers.h>
23
24 #include <sys/stat.h>
25 #include <sys/utsname.h>
26 #include <errno.h>
27
28 #define PTS_BUF_SIZE 4096
29
30 typedef struct private_pts_t private_pts_t;
31
32 /**
33 * Private data of a pts_t object.
34 *
35 */
36 struct private_pts_t {
37
38 /**
39 * Public pts_t interface.
40 */
41 pts_t public;
42
43 /**
44 * PTS Protocol Capabilities
45 */
46 pts_proto_caps_flag_t proto_caps;
47
48 /**
49 * PTS Measurement Algorithm
50 */
51 pts_meas_algorithms_t algorithm;
52
53 /**
54 * Platform and OS Info
55 */
56 char *platform_info;
57
58 /**
59 * Do we have an activated TPM
60 */
61 bool has_tpm;
62
63 /**
64 * Contains a TPM_CAP_VERSION_INFO struct
65 */
66 chunk_t tpm_version_info;
67
68 /**
69 * Contains a Attestation Identity Key or Certificate
70 */
71 certificate_t *aik;
72
73 };
74
75 METHOD(pts_t, get_proto_caps, pts_proto_caps_flag_t,
76 private_pts_t *this)
77 {
78 return this->proto_caps;
79 }
80
81 METHOD(pts_t, set_proto_caps, void,
82 private_pts_t *this, pts_proto_caps_flag_t flags)
83 {
84 this->proto_caps = flags;
85 DBG2(DBG_IMC, "supported PTS protocol capabilities: %s%s%s%s%s",
86 flags & PTS_PROTO_CAPS_C ? "C" : ".",
87 flags & PTS_PROTO_CAPS_V ? "V" : ".",
88 flags & PTS_PROTO_CAPS_D ? "D" : ".",
89 flags & PTS_PROTO_CAPS_T ? "T" : ".",
90 flags & PTS_PROTO_CAPS_X ? "X" : ".");
91 }
92
93 METHOD(pts_t, get_meas_algorithm, pts_meas_algorithms_t,
94 private_pts_t *this)
95 {
96 return this->algorithm;
97 }
98
99 METHOD(pts_t, set_meas_algorithm, void,
100 private_pts_t *this, pts_meas_algorithms_t algorithm)
101 {
102 hash_algorithm_t hash_alg;
103
104 hash_alg = pts_meas_to_hash_algorithm(algorithm);
105 DBG2(DBG_IMC, "selected PTS measurement algorithm is %N",
106 hash_algorithm_names, hash_alg);
107 if (hash_alg != HASH_UNKNOWN)
108 {
109 this->algorithm = algorithm;
110 }
111 }
112
113 /**
114 * Print TPM 1.2 Version Info
115 */
116 static void print_tpm_version_info(private_pts_t *this)
117 {
118 TPM_CAP_VERSION_INFO versionInfo;
119 UINT64 offset = 0;
120 TSS_RESULT result;
121
122 result = Trspi_UnloadBlob_CAP_VERSION_INFO(&offset,
123 this->tpm_version_info.ptr, &versionInfo);
124 if (result != TSS_SUCCESS)
125 {
126 DBG1(DBG_TNC, "could not parse tpm version info: tss error 0x%x",
127 result);
128 }
129 else
130 {
131 DBG2(DBG_TNC, "TPM 1.2 Version Info: Chip Version: %hhu.%hhu.%hhu.%hhu,"
132 " Spec Level: %hu, Errata Rev: %hhu, Vendor ID: %.4s",
133 versionInfo.version.major, versionInfo.version.minor,
134 versionInfo.version.revMajor, versionInfo.version.revMinor,
135 versionInfo.specLevel, versionInfo.errataRev,
136 versionInfo.tpmVendorID);
137 }
138 }
139
140 METHOD(pts_t, get_platform_info, char*,
141 private_pts_t *this)
142 {
143 return this->platform_info;
144 }
145
146 METHOD(pts_t, set_platform_info, void,
147 private_pts_t *this, char *info)
148 {
149 free(this->platform_info);
150 this->platform_info = strdup(info);
151 }
152
153 METHOD(pts_t, get_tpm_version_info, bool,
154 private_pts_t *this, chunk_t *info)
155 {
156 if (!this->has_tpm)
157 {
158 return FALSE;
159 }
160 *info = this->tpm_version_info;
161 print_tpm_version_info(this);
162 return TRUE;
163 }
164
165 METHOD(pts_t, set_tpm_version_info, void,
166 private_pts_t *this, chunk_t info)
167 {
168 this->tpm_version_info = chunk_clone(info);
169 print_tpm_version_info(this);
170 }
171
172 /**
173 * Load an AIK certificate or public key,
174 * the certificate having precedence over the public key if both are present
175 */
176 static void load_aik(private_pts_t *this)
177 {
178 char *cert_path, *key_path;
179
180 cert_path = lib->settings->get_str(lib->settings,
181 "libimcv.plugins.imc-attestation.aik_cert", NULL);
182 key_path = lib->settings->get_str(lib->settings,
183 "libimcv.plugins.imc-attestation.aik_key", NULL);
184
185 if (cert_path)
186 {
187 this->aik = lib->creds->create(lib->creds, CRED_CERTIFICATE,
188 CERT_X509, BUILD_FROM_FILE,
189 cert_path, BUILD_END);
190 if (this->aik)
191 {
192 DBG2(DBG_IMC, "loaded AIK certificate from '%s'", cert_path);
193 return;
194 }
195 }
196 if (key_path)
197 {
198 this->aik = lib->creds->create(lib->creds, CRED_CERTIFICATE,
199 CERT_TRUSTED_PUBKEY, BUILD_FROM_FILE,
200 key_path, BUILD_END);
201 if (this->aik)
202 {
203 DBG2(DBG_IMC, "loaded AIK public key from '%s'", key_path);
204 return;
205 }
206 }
207 DBG1(DBG_IMC, "neither AIK certificate nor public key is available");
208 }
209
210 METHOD(pts_t, get_aik, certificate_t*,
211 private_pts_t *this)
212 {
213 return this->aik;
214 }
215
216 METHOD(pts_t, set_aik, void,
217 private_pts_t *this, certificate_t *aik)
218 {
219 DESTROY_IF(this->aik);
220 this->aik = aik->get_ref(aik);
221 }
222
223 /**
224 * Compute a hash over a file
225 */
226 static bool hash_file(hasher_t *hasher, char *pathname, u_char *hash)
227 {
228 u_char buffer[PTS_BUF_SIZE];
229 FILE *file;
230 int bytes_read;
231
232 file = fopen(pathname, "rb");
233 if (!file)
234 {
235 DBG1(DBG_IMC," file '%s' can not be opened, %s", pathname,
236 strerror(errno));
237 return FALSE;
238 }
239 while (TRUE)
240 {
241 bytes_read = fread(buffer, 1, sizeof(buffer), file);
242 if (bytes_read > 0)
243 {
244 hasher->get_hash(hasher, chunk_create(buffer, bytes_read), NULL);
245 }
246 else
247 {
248 hasher->get_hash(hasher, chunk_empty, hash);
249 break;
250 }
251 }
252 fclose(file);
253
254 return TRUE;
255 }
256
257 /**
258 * Get the relative filename of a fully qualified file pathname
259 */
260 static char* get_filename(char *pathname)
261 {
262 char *pos, *filename;
263
264 pos = filename = pathname;
265 while (pos && *(++pos) != '\0')
266 {
267 filename = pos;
268 pos = strchr(filename, '/');
269 }
270 return filename;
271 }
272
273 METHOD(pts_t, is_path_valid, bool, private_pts_t *this, char *path,
274 pts_error_code_t *error_code)
275 {
276 int error;
277 struct stat sb;
278
279 error_code = NULL;
280 error = stat(path, &sb);
281 if (error == 0)
282 {
283 return TRUE;
284 }
285 else if (error == ENOENT || error == ENOTDIR)
286 {
287 DBG1(DBG_IMC, "file/directory does not exist %s", path);
288 *error_code = TCG_PTS_FILE_NOT_FOUND;
289 }
290 else if (error == EFAULT)
291 {
292 DBG1(DBG_IMC, "bad address %s", path);
293 *error_code = TCG_PTS_INVALID_PATH;
294 }
295 else
296 {
297 DBG1(DBG_IMC, "error: %s occured while validating path: %s", strerror(error), path);
298 return FALSE;
299 }
300
301 return TRUE;
302 }
303
304 METHOD(pts_t, do_measurements, pts_file_meas_t*,
305 private_pts_t *this, u_int16_t request_id, char *pathname, bool is_directory)
306 {
307 hasher_t *hasher;
308 hash_algorithm_t hash_alg;
309 u_char hash[HASH_SIZE_SHA384];
310 chunk_t measurement;
311 pts_file_meas_t *measurements;
312
313 /* Create a hasher */
314 hash_alg = pts_meas_to_hash_algorithm(this->algorithm);
315 hasher = lib->crypto->create_hasher(lib->crypto, hash_alg);
316 if (!hasher)
317 {
318 DBG1(DBG_IMC, " hasher %N not available", hash_algorithm_names, hash_alg);
319 return NULL;
320 }
321
322 /* Create a measurement object */
323 measurements = pts_file_meas_create(request_id);
324
325 /* Link the hash to the measurement and set the measurement length */
326 measurement = chunk_create(hash, hasher->get_hash_size(hasher));
327
328 if (is_directory)
329 {
330 enumerator_t *enumerator;
331 char *rel_name, *abs_name;
332 struct stat st;
333
334 enumerator = enumerator_create_directory(pathname);
335 if (!enumerator)
336 {
337 DBG1(DBG_IMC," directory '%s' can not be opened, %s", pathname,
338 strerror(errno));
339 hasher->destroy(hasher);
340 measurements->destroy(measurements);
341 return NULL;
342 }
343 while (enumerator->enumerate(enumerator, &rel_name, &abs_name, &st))
344 {
345 /* measure regular files only */
346 if (S_ISREG(st.st_mode) && *rel_name != '.')
347 {
348 if (!hash_file(hasher, abs_name, hash))
349 {
350 enumerator->destroy(enumerator);
351 hasher->destroy(hasher);
352 measurements->destroy(measurements);
353 return NULL;
354 }
355 DBG2(DBG_IMC, " %#B for '%s'", &measurement, rel_name);
356 measurements->add(measurements, rel_name, measurement);
357 }
358 }
359 enumerator->destroy(enumerator);
360 }
361 else
362 {
363 char *filename;
364
365 if (!hash_file(hasher, pathname, hash))
366 {
367 hasher->destroy(hasher);
368 measurements->destroy(measurements);
369 return NULL;
370 }
371 filename = get_filename(pathname);
372 DBG2(DBG_IMC, " %#B for '%s'", &measurement, filename);
373 measurements->add(measurements, filename, measurement);
374 }
375 hasher->destroy(hasher);
376
377 return measurements;
378 }
379
380 METHOD(pts_t, destroy, void,
381 private_pts_t *this)
382 {
383 DESTROY_IF(this->aik);
384 free(this->platform_info);
385 free(this->tpm_version_info.ptr);
386 free(this);
387 }
388
389 /**
390 * Determine Linux distribution and hardware platform
391 */
392 static char* extract_platform_info(void)
393 {
394 FILE *file;
395 char buf[BUF_LEN], *pos, *value = NULL;
396 int i, len;
397 struct utsname uninfo;
398
399 /* Linux/Unix distribution release info (from http://linuxmafia.com) */
400 const char* releases[] = {
401 "/etc/lsb-release", "/etc/debian_version",
402 "/etc/SuSE-release", "/etc/novell-release",
403 "/etc/sles-release", "/etc/redhat-release",
404 "/etc/fedora-release", "/etc/gentoo-release",
405 "/etc/slackware-version", "/etc/annvix-release",
406 "/etc/arch-release", "/etc/arklinux-release",
407 "/etc/aurox-release", "/etc/blackcat-release",
408 "/etc/cobalt-release", "/etc/conectiva-release",
409 "/etc/debian_release", "/etc/immunix-release",
410 "/etc/lfs-release", "/etc/linuxppc-release",
411 "/etc/mandrake-release", "/etc/mandriva-release",
412 "/etc/mandrakelinux-release", "/etc/mklinux-release",
413 "/etc/pld-release", "/etc/redhat_version",
414 "/etc/slackware-release", "/etc/e-smith-release",
415 "/etc/release", "/etc/sun-release",
416 "/etc/tinysofa-release", "/etc/turbolinux-release",
417 "/etc/ultrapenguin-release", "/etc/UnitedLinux-release",
418 "/etc/va-release", "/etc/yellowdog-release"
419 };
420
421 const char description[] = "DISTRIB_DESCRIPTION=\"";
422
423 for (i = 0; i < countof(releases); i++)
424 {
425 file = fopen(releases[i], "r");
426 if (!file)
427 {
428 continue;
429 }
430 fseek(file, 0, SEEK_END);
431 len = min(ftell(file), sizeof(buf)-1);
432 rewind(file);
433 buf[len] = '\0';
434 if (fread(buf, 1, len, file) != len)
435 {
436 DBG1(DBG_IMC, "failed to read file '%s'", releases[i]);
437 fclose(file);
438 return NULL;
439 }
440 fclose(file);
441
442 if (i == 0) /* LSB release */
443 {
444 pos = strstr(buf, description);
445 if (!pos)
446 {
447 DBG1(DBG_IMC, "failed to find begin of lsb-release "
448 "DESCRIPTION field");
449 return NULL;
450 }
451 value = pos + strlen(description);
452 pos = strchr(value, '"');
453 if (!pos)
454 {
455 DBG1(DBG_IMC, "failed to find end of lsb-release "
456 "DESCRIPTION field");
457 return NULL;
458 }
459 }
460 else
461 {
462 value = buf;
463 pos = strchr(value, '\n');
464 if (!pos)
465 {
466 DBG1(DBG_IMC, "failed to find end of release string");
467 return NULL;
468 }
469 }
470 break;
471 }
472
473 if (!value)
474 {
475 DBG1(DBG_IMC, "no distribution release file found");
476 return NULL;
477 }
478
479 if (uname(&uninfo) < 0)
480 {
481 DBG1(DBG_IMC, "could not retrieve machine architecture");
482 return NULL;
483 }
484
485 *pos++ = ' ';
486 len = sizeof(buf)-1 + (pos - buf);
487 strncpy(pos, uninfo.machine, len);
488
489 DBG1(DBG_IMC, "platform is '%s'", value);
490 return strdup(value);
491 }
492
493 /**
494 * Check for a TPM by querying for TPM Version Info
495 */
496 static bool has_tpm(private_pts_t *this)
497 {
498 TSS_HCONTEXT hContext;
499 TSS_HTPM hTPM;
500 TSS_RESULT result;
501 u_int32_t version_info_len;
502
503 result = Tspi_Context_Create(&hContext);
504 if (result != TSS_SUCCESS)
505 {
506 DBG1(DBG_IMC, "TPM context could not be created: tss error 0x%x", result);
507 return FALSE;
508 }
509 result = Tspi_Context_Connect(hContext, NULL);
510 if (result != TSS_SUCCESS)
511 {
512 goto err;
513 }
514 result = Tspi_Context_GetTpmObject (hContext, &hTPM);
515 if (result != TSS_SUCCESS)
516 {
517 goto err;
518 }
519 result = Tspi_TPM_GetCapability(hTPM, TSS_TPMCAP_VERSION_VAL, 0, NULL,
520 &version_info_len,
521 &this->tpm_version_info.ptr);
522 this->tpm_version_info.len = version_info_len;
523 if (result != TSS_SUCCESS)
524 {
525 goto err;
526 }
527 this->tpm_version_info = chunk_clone(this->tpm_version_info);
528 return TRUE;
529
530 err:
531 DBG1(DBG_IMC, "TPM not available: tss error 0x%x", result);
532 Tspi_Context_Close(hContext);
533 return FALSE;
534 }
535
536 /**
537 * See header
538 */
539 pts_t *pts_create(bool is_imc)
540 {
541 private_pts_t *this;
542
543 INIT(this,
544 .public = {
545 .get_proto_caps = _get_proto_caps,
546 .set_proto_caps = _set_proto_caps,
547 .get_meas_algorithm = _get_meas_algorithm,
548 .set_meas_algorithm = _set_meas_algorithm,
549 .get_platform_info = _get_platform_info,
550 .set_platform_info = _set_platform_info,
551 .get_tpm_version_info = _get_tpm_version_info,
552 .set_tpm_version_info = _set_tpm_version_info,
553 .get_aik = _get_aik,
554 .set_aik = _set_aik,
555 .is_path_valid = _is_path_valid,
556 .do_measurements = _do_measurements,
557 .destroy = _destroy,
558 },
559 .proto_caps = PTS_PROTO_CAPS_V,
560 .algorithm = PTS_MEAS_ALGO_SHA256,
561 );
562
563 if (is_imc)
564 {
565 this->platform_info = extract_platform_info();
566
567 if (has_tpm(this))
568 {
569 this->has_tpm = TRUE;
570 this->proto_caps |= PTS_PROTO_CAPS_T;
571 load_aik(this);
572 }
573 }
574 else
575 {
576 this->proto_caps |= PTS_PROTO_CAPS_T | PTS_PROTO_CAPS_C;
577 }
578
579 return &this->public;
580 }
581