xref: /openbmc/linux/drivers/char/tpm/tpm-sysfs.c (revision b8265621)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (C) 2004 IBM Corporation
4  * Authors:
5  * Leendert van Doorn <leendert@watson.ibm.com>
6  * Dave Safford <safford@watson.ibm.com>
7  * Reiner Sailer <sailer@watson.ibm.com>
8  * Kylene Hall <kjhall@us.ibm.com>
9  *
10  * Copyright (C) 2013 Obsidian Research Corp
11  * Jason Gunthorpe <jgunthorpe@obsidianresearch.com>
12  *
13  * sysfs filesystem inspection interface to the TPM
14  */
15 #include <linux/device.h>
16 #include "tpm.h"
17 
18 struct tpm_readpubek_out {
19 	u8 algorithm[4];
20 	u8 encscheme[2];
21 	u8 sigscheme[2];
22 	__be32 paramsize;
23 	u8 parameters[12];
24 	__be32 keysize;
25 	u8 modulus[256];
26 	u8 checksum[20];
27 } __packed;
28 
29 #define READ_PUBEK_RESULT_MIN_BODY_SIZE (28 + 256)
30 #define TPM_ORD_READPUBEK 124
31 
32 static ssize_t pubek_show(struct device *dev, struct device_attribute *attr,
33 			  char *buf)
34 {
35 	struct tpm_buf tpm_buf;
36 	struct tpm_readpubek_out *out;
37 	int i;
38 	char *str = buf;
39 	struct tpm_chip *chip = to_tpm_chip(dev);
40 	char anti_replay[20];
41 
42 	memset(&anti_replay, 0, sizeof(anti_replay));
43 
44 	if (tpm_try_get_ops(chip))
45 		return 0;
46 
47 	if (tpm_buf_init(&tpm_buf, TPM_TAG_RQU_COMMAND, TPM_ORD_READPUBEK))
48 		goto out_ops;
49 
50 	tpm_buf_append(&tpm_buf, anti_replay, sizeof(anti_replay));
51 
52 	if (tpm_transmit_cmd(chip, &tpm_buf, READ_PUBEK_RESULT_MIN_BODY_SIZE,
53 			     "attempting to read the PUBEK"))
54 		goto out_buf;
55 
56 	out = (struct tpm_readpubek_out *)&tpm_buf.data[10];
57 	str +=
58 	    sprintf(str,
59 		    "Algorithm: %02X %02X %02X %02X\n"
60 		    "Encscheme: %02X %02X\n"
61 		    "Sigscheme: %02X %02X\n"
62 		    "Parameters: %02X %02X %02X %02X "
63 		    "%02X %02X %02X %02X "
64 		    "%02X %02X %02X %02X\n"
65 		    "Modulus length: %d\n"
66 		    "Modulus:\n",
67 		    out->algorithm[0], out->algorithm[1], out->algorithm[2],
68 		    out->algorithm[3],
69 		    out->encscheme[0], out->encscheme[1],
70 		    out->sigscheme[0], out->sigscheme[1],
71 		    out->parameters[0], out->parameters[1],
72 		    out->parameters[2], out->parameters[3],
73 		    out->parameters[4], out->parameters[5],
74 		    out->parameters[6], out->parameters[7],
75 		    out->parameters[8], out->parameters[9],
76 		    out->parameters[10], out->parameters[11],
77 		    be32_to_cpu(out->keysize));
78 
79 	for (i = 0; i < 256; i++) {
80 		str += sprintf(str, "%02X ", out->modulus[i]);
81 		if ((i + 1) % 16 == 0)
82 			str += sprintf(str, "\n");
83 	}
84 
85 out_buf:
86 	tpm_buf_destroy(&tpm_buf);
87 out_ops:
88 	tpm_put_ops(chip);
89 	return str - buf;
90 }
91 static DEVICE_ATTR_RO(pubek);
92 
93 static ssize_t pcrs_show(struct device *dev, struct device_attribute *attr,
94 			 char *buf)
95 {
96 	cap_t cap;
97 	u8 digest[TPM_DIGEST_SIZE];
98 	u32 i, j, num_pcrs;
99 	char *str = buf;
100 	struct tpm_chip *chip = to_tpm_chip(dev);
101 
102 	if (tpm_try_get_ops(chip))
103 		return 0;
104 
105 	if (tpm1_getcap(chip, TPM_CAP_PROP_PCR, &cap,
106 			"attempting to determine the number of PCRS",
107 			sizeof(cap.num_pcrs))) {
108 		tpm_put_ops(chip);
109 		return 0;
110 	}
111 
112 	num_pcrs = be32_to_cpu(cap.num_pcrs);
113 	for (i = 0; i < num_pcrs; i++) {
114 		if (tpm1_pcr_read(chip, i, digest)) {
115 			str = buf;
116 			break;
117 		}
118 		str += sprintf(str, "PCR-%02d: ", i);
119 		for (j = 0; j < TPM_DIGEST_SIZE; j++)
120 			str += sprintf(str, "%02X ", digest[j]);
121 		str += sprintf(str, "\n");
122 	}
123 	tpm_put_ops(chip);
124 	return str - buf;
125 }
126 static DEVICE_ATTR_RO(pcrs);
127 
128 static ssize_t enabled_show(struct device *dev, struct device_attribute *attr,
129 		     char *buf)
130 {
131 	struct tpm_chip *chip = to_tpm_chip(dev);
132 	ssize_t rc = 0;
133 	cap_t cap;
134 
135 	if (tpm_try_get_ops(chip))
136 		return 0;
137 
138 	if (tpm1_getcap(chip, TPM_CAP_FLAG_PERM, &cap,
139 			"attempting to determine the permanent enabled state",
140 			sizeof(cap.perm_flags)))
141 		goto out_ops;
142 
143 	rc = sprintf(buf, "%d\n", !cap.perm_flags.disable);
144 out_ops:
145 	tpm_put_ops(chip);
146 	return rc;
147 }
148 static DEVICE_ATTR_RO(enabled);
149 
150 static ssize_t active_show(struct device *dev, struct device_attribute *attr,
151 		    char *buf)
152 {
153 	struct tpm_chip *chip = to_tpm_chip(dev);
154 	ssize_t rc = 0;
155 	cap_t cap;
156 
157 	if (tpm_try_get_ops(chip))
158 		return 0;
159 
160 	if (tpm1_getcap(chip, TPM_CAP_FLAG_PERM, &cap,
161 			"attempting to determine the permanent active state",
162 			sizeof(cap.perm_flags)))
163 		goto out_ops;
164 
165 	rc = sprintf(buf, "%d\n", !cap.perm_flags.deactivated);
166 out_ops:
167 	tpm_put_ops(chip);
168 	return rc;
169 }
170 static DEVICE_ATTR_RO(active);
171 
172 static ssize_t owned_show(struct device *dev, struct device_attribute *attr,
173 			  char *buf)
174 {
175 	struct tpm_chip *chip = to_tpm_chip(dev);
176 	ssize_t rc = 0;
177 	cap_t cap;
178 
179 	if (tpm_try_get_ops(chip))
180 		return 0;
181 
182 	if (tpm1_getcap(to_tpm_chip(dev), TPM_CAP_PROP_OWNER, &cap,
183 			"attempting to determine the owner state",
184 			sizeof(cap.owned)))
185 		goto out_ops;
186 
187 	rc = sprintf(buf, "%d\n", cap.owned);
188 out_ops:
189 	tpm_put_ops(chip);
190 	return rc;
191 }
192 static DEVICE_ATTR_RO(owned);
193 
194 static ssize_t temp_deactivated_show(struct device *dev,
195 				     struct device_attribute *attr, char *buf)
196 {
197 	struct tpm_chip *chip = to_tpm_chip(dev);
198 	ssize_t rc = 0;
199 	cap_t cap;
200 
201 	if (tpm_try_get_ops(chip))
202 		return 0;
203 
204 	if (tpm1_getcap(to_tpm_chip(dev), TPM_CAP_FLAG_VOL, &cap,
205 			"attempting to determine the temporary state",
206 			sizeof(cap.stclear_flags)))
207 		goto out_ops;
208 
209 	rc = sprintf(buf, "%d\n", cap.stclear_flags.deactivated);
210 out_ops:
211 	tpm_put_ops(chip);
212 	return rc;
213 }
214 static DEVICE_ATTR_RO(temp_deactivated);
215 
216 static ssize_t caps_show(struct device *dev, struct device_attribute *attr,
217 			 char *buf)
218 {
219 	struct tpm_chip *chip = to_tpm_chip(dev);
220 	struct tpm1_version *version;
221 	ssize_t rc = 0;
222 	char *str = buf;
223 	cap_t cap;
224 
225 	if (tpm_try_get_ops(chip))
226 		return 0;
227 
228 	if (tpm1_getcap(chip, TPM_CAP_PROP_MANUFACTURER, &cap,
229 			"attempting to determine the manufacturer",
230 			sizeof(cap.manufacturer_id)))
231 		goto out_ops;
232 
233 	str += sprintf(str, "Manufacturer: 0x%x\n",
234 		       be32_to_cpu(cap.manufacturer_id));
235 
236 	/* TPM 1.2 */
237 	if (!tpm1_getcap(chip, TPM_CAP_VERSION_1_2, &cap,
238 			 "attempting to determine the 1.2 version",
239 			 sizeof(cap.version2))) {
240 		version = &cap.version2.version;
241 		goto out_print;
242 	}
243 
244 	/* TPM 1.1 */
245 	if (tpm1_getcap(chip, TPM_CAP_VERSION_1_1, &cap,
246 			"attempting to determine the 1.1 version",
247 			sizeof(cap.version1))) {
248 		goto out_ops;
249 	}
250 
251 	version = &cap.version1;
252 
253 out_print:
254 	str += sprintf(str,
255 		       "TCG version: %d.%d\nFirmware version: %d.%d\n",
256 		       version->major, version->minor,
257 		       version->rev_major, version->rev_minor);
258 
259 	rc = str - buf;
260 
261 out_ops:
262 	tpm_put_ops(chip);
263 	return rc;
264 }
265 static DEVICE_ATTR_RO(caps);
266 
267 static ssize_t cancel_store(struct device *dev, struct device_attribute *attr,
268 			    const char *buf, size_t count)
269 {
270 	struct tpm_chip *chip = to_tpm_chip(dev);
271 
272 	if (tpm_try_get_ops(chip))
273 		return 0;
274 
275 	chip->ops->cancel(chip);
276 	tpm_put_ops(chip);
277 	return count;
278 }
279 static DEVICE_ATTR_WO(cancel);
280 
281 static ssize_t durations_show(struct device *dev, struct device_attribute *attr,
282 			      char *buf)
283 {
284 	struct tpm_chip *chip = to_tpm_chip(dev);
285 
286 	if (chip->duration[TPM_LONG] == 0)
287 		return 0;
288 
289 	return sprintf(buf, "%d %d %d [%s]\n",
290 		       jiffies_to_usecs(chip->duration[TPM_SHORT]),
291 		       jiffies_to_usecs(chip->duration[TPM_MEDIUM]),
292 		       jiffies_to_usecs(chip->duration[TPM_LONG]),
293 		       chip->duration_adjusted
294 		       ? "adjusted" : "original");
295 }
296 static DEVICE_ATTR_RO(durations);
297 
298 static ssize_t timeouts_show(struct device *dev, struct device_attribute *attr,
299 			     char *buf)
300 {
301 	struct tpm_chip *chip = to_tpm_chip(dev);
302 
303 	return sprintf(buf, "%d %d %d %d [%s]\n",
304 		       jiffies_to_usecs(chip->timeout_a),
305 		       jiffies_to_usecs(chip->timeout_b),
306 		       jiffies_to_usecs(chip->timeout_c),
307 		       jiffies_to_usecs(chip->timeout_d),
308 		       chip->timeout_adjusted
309 		       ? "adjusted" : "original");
310 }
311 static DEVICE_ATTR_RO(timeouts);
312 
313 static ssize_t tpm_version_major_show(struct device *dev,
314 				  struct device_attribute *attr, char *buf)
315 {
316 	struct tpm_chip *chip = to_tpm_chip(dev);
317 
318 	return sprintf(buf, "%s\n", chip->flags & TPM_CHIP_FLAG_TPM2
319 		       ? "2" : "1");
320 }
321 static DEVICE_ATTR_RO(tpm_version_major);
322 
323 static struct attribute *tpm1_dev_attrs[] = {
324 	&dev_attr_pubek.attr,
325 	&dev_attr_pcrs.attr,
326 	&dev_attr_enabled.attr,
327 	&dev_attr_active.attr,
328 	&dev_attr_owned.attr,
329 	&dev_attr_temp_deactivated.attr,
330 	&dev_attr_caps.attr,
331 	&dev_attr_cancel.attr,
332 	&dev_attr_durations.attr,
333 	&dev_attr_timeouts.attr,
334 	&dev_attr_tpm_version_major.attr,
335 	NULL,
336 };
337 
338 static struct attribute *tpm2_dev_attrs[] = {
339 	&dev_attr_tpm_version_major.attr,
340 	NULL
341 };
342 
343 static const struct attribute_group tpm1_dev_group = {
344 	.attrs = tpm1_dev_attrs,
345 };
346 
347 static const struct attribute_group tpm2_dev_group = {
348 	.attrs = tpm2_dev_attrs,
349 };
350 
351 void tpm_sysfs_add_device(struct tpm_chip *chip)
352 {
353 	WARN_ON(chip->groups_cnt != 0);
354 	if (chip->flags & TPM_CHIP_FLAG_TPM2)
355 		chip->groups[chip->groups_cnt++] = &tpm2_dev_group;
356 	else
357 		chip->groups[chip->groups_cnt++] = &tpm1_dev_group;
358 }
359