1 /*
2 * Copyright (C) 2005, 2012 IBM Corporation
3 *
4 * Authors:
5 * Kent Yoder <key@linux.vnet.ibm.com>
6 * Seiji Munetoh <munetoh@jp.ibm.com>
7 * Stefan Berger <stefanb@us.ibm.com>
8 * Reiner Sailer <sailer@watson.ibm.com>
9 * Kylene Hall <kjhall@us.ibm.com>
10 *
11 * Maintained by: <tpmdd-devel@lists.sourceforge.net>
12 *
13 * Access to the eventlog created by a system's firmware / BIOS
14 *
15 * This program is free software; you can redistribute it and/or
16 * modify it under the terms of the GNU General Public License
17 * as published by the Free Software Foundation; either version
18 * 2 of the License, or (at your option) any later version.
19 *
20 */
21
22 #include <linux/seq_file.h>
23 #include <linux/fs.h>
24 #include <linux/security.h>
25 #include <linux/module.h>
26 #include <linux/slab.h>
27
28 #include "tpm.h"
29 #include "tpm_eventlog.h"
30
31
32 static const char* tcpa_event_type_strings[] = {
33 "PREBOOT",
34 "POST CODE",
35 "",
36 "NO ACTION",
37 "SEPARATOR",
38 "ACTION",
39 "EVENT TAG",
40 "S-CRTM Contents",
41 "S-CRTM Version",
42 "CPU Microcode",
43 "Platform Config Flags",
44 "Table of Devices",
45 "Compact Hash",
46 "IPL",
47 "IPL Partition Data",
48 "Non-Host Code",
49 "Non-Host Config",
50 "Non-Host Info"
51 };
52
53 static const char* tcpa_pc_event_id_strings[] = {
54 "",
55 "SMBIOS",
56 "BIS Certificate",
57 "POST BIOS ",
58 "ESCD ",
59 "CMOS",
60 "NVRAM",
61 "Option ROM",
62 "Option ROM config",
63 "",
64 "Option ROM microcode ",
65 "S-CRTM Version",
66 "S-CRTM Contents ",
67 "POST Contents ",
68 "Table of Devices",
69 };
70
71 /* returns pointer to start of pos. entry of tcg log */
tpm_bios_measurements_start(struct seq_file * m,loff_t * pos)72 static void *tpm_bios_measurements_start(struct seq_file *m, loff_t *pos)
73 {
74 loff_t i;
75 struct tpm_bios_log *log = m->private;
76 void *addr = log->bios_event_log;
77 void *limit = log->bios_event_log_end;
78 struct tcpa_event *event;
79 u32 converted_event_size;
80 u32 converted_event_type;
81
82
83 /* read over *pos measurements */
84 for (i = 0; i < *pos; i++) {
85 event = addr;
86
87 converted_event_size =
88 do_endian_conversion(event->event_size);
89 converted_event_type =
90 do_endian_conversion(event->event_type);
91
92 if ((addr + sizeof(struct tcpa_event)) < limit) {
93 if ((converted_event_type == 0) &&
94 (converted_event_size == 0))
95 return NULL;
96 addr += (sizeof(struct tcpa_event) +
97 converted_event_size);
98 }
99 }
100
101 /* now check if current entry is valid */
102 if ((addr + sizeof(struct tcpa_event)) >= limit)
103 return NULL;
104
105 event = addr;
106
107 converted_event_size = do_endian_conversion(event->event_size);
108 converted_event_type = do_endian_conversion(event->event_type);
109
110 if (((converted_event_type == 0) && (converted_event_size == 0))
111 || ((addr + sizeof(struct tcpa_event) + converted_event_size)
112 >= limit))
113 return NULL;
114
115 return addr;
116 }
117
tpm_bios_measurements_next(struct seq_file * m,void * v,loff_t * pos)118 static void *tpm_bios_measurements_next(struct seq_file *m, void *v,
119 loff_t *pos)
120 {
121 struct tcpa_event *event = v;
122 struct tpm_bios_log *log = m->private;
123 void *limit = log->bios_event_log_end;
124 u32 converted_event_size;
125 u32 converted_event_type;
126
127 converted_event_size = do_endian_conversion(event->event_size);
128
129 v += sizeof(struct tcpa_event) + converted_event_size;
130
131 /* now check if current entry is valid */
132 if ((v + sizeof(struct tcpa_event)) >= limit)
133 return NULL;
134
135 event = v;
136
137 converted_event_size = do_endian_conversion(event->event_size);
138 converted_event_type = do_endian_conversion(event->event_type);
139
140 if (((converted_event_type == 0) && (converted_event_size == 0)) ||
141 ((v + sizeof(struct tcpa_event) + converted_event_size) >= limit))
142 return NULL;
143
144 (*pos)++;
145 return v;
146 }
147
tpm_bios_measurements_stop(struct seq_file * m,void * v)148 static void tpm_bios_measurements_stop(struct seq_file *m, void *v)
149 {
150 }
151
get_event_name(char * dest,struct tcpa_event * event,unsigned char * event_entry)152 static int get_event_name(char *dest, struct tcpa_event *event,
153 unsigned char * event_entry)
154 {
155 const char *name = "";
156 /* 41 so there is room for 40 data and 1 nul */
157 char data[41] = "";
158 int i, n_len = 0, d_len = 0;
159 struct tcpa_pc_event *pc_event;
160
161 switch (do_endian_conversion(event->event_type)) {
162 case PREBOOT:
163 case POST_CODE:
164 case UNUSED:
165 case NO_ACTION:
166 case SCRTM_CONTENTS:
167 case SCRTM_VERSION:
168 case CPU_MICROCODE:
169 case PLATFORM_CONFIG_FLAGS:
170 case TABLE_OF_DEVICES:
171 case COMPACT_HASH:
172 case IPL:
173 case IPL_PARTITION_DATA:
174 case NONHOST_CODE:
175 case NONHOST_CONFIG:
176 case NONHOST_INFO:
177 name = tcpa_event_type_strings[do_endian_conversion
178 (event->event_type)];
179 n_len = strlen(name);
180 break;
181 case SEPARATOR:
182 case ACTION:
183 if (MAX_TEXT_EVENT >
184 do_endian_conversion(event->event_size)) {
185 name = event_entry;
186 n_len = do_endian_conversion(event->event_size);
187 }
188 break;
189 case EVENT_TAG:
190 pc_event = (struct tcpa_pc_event *)event_entry;
191
192 /* ToDo Row data -> Base64 */
193
194 switch (do_endian_conversion(pc_event->event_id)) {
195 case SMBIOS:
196 case BIS_CERT:
197 case CMOS:
198 case NVRAM:
199 case OPTION_ROM_EXEC:
200 case OPTION_ROM_CONFIG:
201 case S_CRTM_VERSION:
202 name = tcpa_pc_event_id_strings[do_endian_conversion
203 (pc_event->event_id)];
204 n_len = strlen(name);
205 break;
206 /* hash data */
207 case POST_BIOS_ROM:
208 case ESCD:
209 case OPTION_ROM_MICROCODE:
210 case S_CRTM_CONTENTS:
211 case POST_CONTENTS:
212 name = tcpa_pc_event_id_strings[do_endian_conversion
213 (pc_event->event_id)];
214 n_len = strlen(name);
215 for (i = 0; i < 20; i++)
216 d_len += sprintf(&data[2*i], "%02x",
217 pc_event->event_data[i]);
218 break;
219 default:
220 break;
221 }
222 default:
223 break;
224 }
225
226 return snprintf(dest, MAX_TEXT_EVENT, "[%.*s%.*s]",
227 n_len, name, d_len, data);
228
229 }
230
tpm_binary_bios_measurements_show(struct seq_file * m,void * v)231 static int tpm_binary_bios_measurements_show(struct seq_file *m, void *v)
232 {
233 struct tcpa_event *event = v;
234 struct tcpa_event temp_event;
235 char *temp_ptr;
236 int i;
237
238 memcpy(&temp_event, event, sizeof(struct tcpa_event));
239
240 /* convert raw integers for endianness */
241 temp_event.pcr_index = do_endian_conversion(event->pcr_index);
242 temp_event.event_type = do_endian_conversion(event->event_type);
243 temp_event.event_size = do_endian_conversion(event->event_size);
244
245 temp_ptr = (char *) &temp_event;
246
247 for (i = 0; i < (sizeof(struct tcpa_event) - 1) ; i++)
248 seq_putc(m, temp_ptr[i]);
249
250 temp_ptr = (char *) v;
251
252 for (i = (sizeof(struct tcpa_event) - 1);
253 i < (sizeof(struct tcpa_event) + temp_event.event_size); i++)
254 seq_putc(m, temp_ptr[i]);
255
256 return 0;
257
258 }
259
tpm_bios_measurements_release(struct inode * inode,struct file * file)260 static int tpm_bios_measurements_release(struct inode *inode,
261 struct file *file)
262 {
263 struct seq_file *seq = file->private_data;
264 struct tpm_bios_log *log = seq->private;
265
266 if (log) {
267 kfree(log->bios_event_log);
268 kfree(log);
269 }
270
271 return seq_release(inode, file);
272 }
273
tpm_ascii_bios_measurements_show(struct seq_file * m,void * v)274 static int tpm_ascii_bios_measurements_show(struct seq_file *m, void *v)
275 {
276 int len = 0;
277 char *eventname;
278 struct tcpa_event *event = v;
279 unsigned char *event_entry =
280 (unsigned char *)(v + sizeof(struct tcpa_event));
281
282 eventname = kmalloc(MAX_TEXT_EVENT, GFP_KERNEL);
283 if (!eventname) {
284 printk(KERN_ERR "%s: ERROR - No Memory for event name\n ",
285 __func__);
286 return -EFAULT;
287 }
288
289 /* 1st: PCR */
290 seq_printf(m, "%2d ", do_endian_conversion(event->pcr_index));
291
292 /* 2nd: SHA1 */
293 seq_printf(m, "%20phN", event->pcr_value);
294
295 /* 3rd: event type identifier */
296 seq_printf(m, " %02x", do_endian_conversion(event->event_type));
297
298 len += get_event_name(eventname, event, event_entry);
299
300 /* 4th: eventname <= max + \'0' delimiter */
301 seq_printf(m, " %s\n", eventname);
302
303 kfree(eventname);
304 return 0;
305 }
306
307 static const struct seq_operations tpm_ascii_b_measurments_seqops = {
308 .start = tpm_bios_measurements_start,
309 .next = tpm_bios_measurements_next,
310 .stop = tpm_bios_measurements_stop,
311 .show = tpm_ascii_bios_measurements_show,
312 };
313
314 static const struct seq_operations tpm_binary_b_measurments_seqops = {
315 .start = tpm_bios_measurements_start,
316 .next = tpm_bios_measurements_next,
317 .stop = tpm_bios_measurements_stop,
318 .show = tpm_binary_bios_measurements_show,
319 };
320
tpm_ascii_bios_measurements_open(struct inode * inode,struct file * file)321 static int tpm_ascii_bios_measurements_open(struct inode *inode,
322 struct file *file)
323 {
324 int err;
325 struct tpm_bios_log *log;
326 struct seq_file *seq;
327
328 log = kzalloc(sizeof(struct tpm_bios_log), GFP_KERNEL);
329 if (!log)
330 return -ENOMEM;
331
332 if ((err = read_log(log)))
333 goto out_free;
334
335 /* now register seq file */
336 err = seq_open(file, &tpm_ascii_b_measurments_seqops);
337 if (!err) {
338 seq = file->private_data;
339 seq->private = log;
340 } else {
341 goto out_free;
342 }
343
344 out:
345 return err;
346 out_free:
347 kfree(log->bios_event_log);
348 kfree(log);
349 goto out;
350 }
351
352 static const struct file_operations tpm_ascii_bios_measurements_ops = {
353 .open = tpm_ascii_bios_measurements_open,
354 .read = seq_read,
355 .llseek = seq_lseek,
356 .release = tpm_bios_measurements_release,
357 };
358
tpm_binary_bios_measurements_open(struct inode * inode,struct file * file)359 static int tpm_binary_bios_measurements_open(struct inode *inode,
360 struct file *file)
361 {
362 int err;
363 struct tpm_bios_log *log;
364 struct seq_file *seq;
365
366 log = kzalloc(sizeof(struct tpm_bios_log), GFP_KERNEL);
367 if (!log)
368 return -ENOMEM;
369
370 if ((err = read_log(log)))
371 goto out_free;
372
373 /* now register seq file */
374 err = seq_open(file, &tpm_binary_b_measurments_seqops);
375 if (!err) {
376 seq = file->private_data;
377 seq->private = log;
378 } else {
379 goto out_free;
380 }
381
382 out:
383 return err;
384 out_free:
385 kfree(log->bios_event_log);
386 kfree(log);
387 goto out;
388 }
389
390 static const struct file_operations tpm_binary_bios_measurements_ops = {
391 .open = tpm_binary_bios_measurements_open,
392 .read = seq_read,
393 .llseek = seq_lseek,
394 .release = tpm_bios_measurements_release,
395 };
396
is_bad(void * p)397 static int is_bad(void *p)
398 {
399 if (!p)
400 return 1;
401 if (IS_ERR(p) && (PTR_ERR(p) != -ENODEV))
402 return 1;
403 return 0;
404 }
405
tpm_bios_log_setup(char * name)406 struct dentry **tpm_bios_log_setup(char *name)
407 {
408 struct dentry **ret = NULL, *tpm_dir, *bin_file, *ascii_file;
409
410 tpm_dir = securityfs_create_dir(name, NULL);
411 if (is_bad(tpm_dir))
412 goto out;
413
414 bin_file =
415 securityfs_create_file("binary_bios_measurements",
416 S_IRUSR | S_IRGRP, tpm_dir, NULL,
417 &tpm_binary_bios_measurements_ops);
418 if (is_bad(bin_file))
419 goto out_tpm;
420
421 ascii_file =
422 securityfs_create_file("ascii_bios_measurements",
423 S_IRUSR | S_IRGRP, tpm_dir, NULL,
424 &tpm_ascii_bios_measurements_ops);
425 if (is_bad(ascii_file))
426 goto out_bin;
427
428 ret = kmalloc(3 * sizeof(struct dentry *), GFP_KERNEL);
429 if (!ret)
430 goto out_ascii;
431
432 ret[0] = ascii_file;
433 ret[1] = bin_file;
434 ret[2] = tpm_dir;
435
436 return ret;
437
438 out_ascii:
439 securityfs_remove(ascii_file);
440 out_bin:
441 securityfs_remove(bin_file);
442 out_tpm:
443 securityfs_remove(tpm_dir);
444 out:
445 return NULL;
446 }
447
tpm_bios_log_teardown(struct dentry ** lst)448 void tpm_bios_log_teardown(struct dentry **lst)
449 {
450 int i;
451
452 for (i = 0; i < 3; i++)
453 securityfs_remove(lst[i]);
454 }
455