xref: /openbmc/linux/drivers/char/tpm/tpm-sysfs.c (revision 726bd223)
1 /*
2  * Copyright (C) 2004 IBM Corporation
3  * Authors:
4  * Leendert van Doorn <leendert@watson.ibm.com>
5  * Dave Safford <safford@watson.ibm.com>
6  * Reiner Sailer <sailer@watson.ibm.com>
7  * Kylene Hall <kjhall@us.ibm.com>
8  *
9  * Copyright (C) 2013 Obsidian Research Corp
10  * Jason Gunthorpe <jgunthorpe@obsidianresearch.com>
11  *
12  * sysfs filesystem inspection interface to the TPM
13  *
14  * This program is free software; you can redistribute it and/or
15  * modify it under the terms of the GNU General Public License as
16  * published by the Free Software Foundation, version 2 of the
17  * License.
18  *
19  */
20 #include <linux/device.h>
21 #include "tpm.h"
22 
23 #define READ_PUBEK_RESULT_SIZE 314
24 #define READ_PUBEK_RESULT_MIN_BODY_SIZE (28 + 256)
25 #define TPM_ORD_READPUBEK cpu_to_be32(124)
26 static const struct tpm_input_header tpm_readpubek_header = {
27 	.tag = TPM_TAG_RQU_COMMAND,
28 	.length = cpu_to_be32(30),
29 	.ordinal = TPM_ORD_READPUBEK
30 };
31 static ssize_t pubek_show(struct device *dev, struct device_attribute *attr,
32 			  char *buf)
33 {
34 	u8 *data;
35 	struct tpm_cmd_t tpm_cmd;
36 	ssize_t err;
37 	int i, rc;
38 	char *str = buf;
39 
40 	struct tpm_chip *chip = to_tpm_chip(dev);
41 
42 	tpm_cmd.header.in = tpm_readpubek_header;
43 	err = tpm_transmit_cmd(chip, &tpm_cmd, READ_PUBEK_RESULT_SIZE,
44 			       READ_PUBEK_RESULT_MIN_BODY_SIZE, 0,
45 			       "attempting to read the PUBEK");
46 	if (err)
47 		goto out;
48 
49 	/*
50 	   ignore header 10 bytes
51 	   algorithm 32 bits (1 == RSA )
52 	   encscheme 16 bits
53 	   sigscheme 16 bits
54 	   parameters (RSA 12->bytes: keybit, #primes, expbit)
55 	   keylenbytes 32 bits
56 	   256 byte modulus
57 	   ignore checksum 20 bytes
58 	 */
59 	data = tpm_cmd.params.readpubek_out_buffer;
60 	str +=
61 	    sprintf(str,
62 		    "Algorithm: %02X %02X %02X %02X\n"
63 		    "Encscheme: %02X %02X\n"
64 		    "Sigscheme: %02X %02X\n"
65 		    "Parameters: %02X %02X %02X %02X "
66 		    "%02X %02X %02X %02X "
67 		    "%02X %02X %02X %02X\n"
68 		    "Modulus length: %d\n"
69 		    "Modulus:\n",
70 		    data[0], data[1], data[2], data[3],
71 		    data[4], data[5],
72 		    data[6], data[7],
73 		    data[12], data[13], data[14], data[15],
74 		    data[16], data[17], data[18], data[19],
75 		    data[20], data[21], data[22], data[23],
76 		    be32_to_cpu(*((__be32 *) (data + 24))));
77 
78 	for (i = 0; i < 256; i++) {
79 		str += sprintf(str, "%02X ", data[i + 28]);
80 		if ((i + 1) % 16 == 0)
81 			str += sprintf(str, "\n");
82 	}
83 out:
84 	rc = str - buf;
85 	return rc;
86 }
87 static DEVICE_ATTR_RO(pubek);
88 
89 static ssize_t pcrs_show(struct device *dev, struct device_attribute *attr,
90 			 char *buf)
91 {
92 	cap_t cap;
93 	u8 digest[TPM_DIGEST_SIZE];
94 	ssize_t rc;
95 	int i, j, num_pcrs;
96 	char *str = buf;
97 	struct tpm_chip *chip = to_tpm_chip(dev);
98 
99 	rc = tpm_getcap(chip, TPM_CAP_PROP_PCR, &cap,
100 			"attempting to determine the number of PCRS",
101 			sizeof(cap.num_pcrs));
102 	if (rc)
103 		return 0;
104 
105 	num_pcrs = be32_to_cpu(cap.num_pcrs);
106 	for (i = 0; i < num_pcrs; i++) {
107 		rc = tpm_pcr_read_dev(chip, i, digest);
108 		if (rc)
109 			break;
110 		str += sprintf(str, "PCR-%02d: ", i);
111 		for (j = 0; j < TPM_DIGEST_SIZE; j++)
112 			str += sprintf(str, "%02X ", digest[j]);
113 		str += sprintf(str, "\n");
114 	}
115 	return str - buf;
116 }
117 static DEVICE_ATTR_RO(pcrs);
118 
119 static ssize_t enabled_show(struct device *dev, struct device_attribute *attr,
120 		     char *buf)
121 {
122 	cap_t cap;
123 	ssize_t rc;
124 
125 	rc = tpm_getcap(to_tpm_chip(dev), TPM_CAP_FLAG_PERM, &cap,
126 			"attempting to determine the permanent enabled state",
127 			sizeof(cap.perm_flags));
128 	if (rc)
129 		return 0;
130 
131 	rc = sprintf(buf, "%d\n", !cap.perm_flags.disable);
132 	return rc;
133 }
134 static DEVICE_ATTR_RO(enabled);
135 
136 static ssize_t active_show(struct device *dev, struct device_attribute *attr,
137 		    char *buf)
138 {
139 	cap_t cap;
140 	ssize_t rc;
141 
142 	rc = tpm_getcap(to_tpm_chip(dev), TPM_CAP_FLAG_PERM, &cap,
143 			"attempting to determine the permanent active state",
144 			sizeof(cap.perm_flags));
145 	if (rc)
146 		return 0;
147 
148 	rc = sprintf(buf, "%d\n", !cap.perm_flags.deactivated);
149 	return rc;
150 }
151 static DEVICE_ATTR_RO(active);
152 
153 static ssize_t owned_show(struct device *dev, struct device_attribute *attr,
154 			  char *buf)
155 {
156 	cap_t cap;
157 	ssize_t rc;
158 
159 	rc = tpm_getcap(to_tpm_chip(dev), TPM_CAP_PROP_OWNER, &cap,
160 			"attempting to determine the owner state",
161 			sizeof(cap.owned));
162 	if (rc)
163 		return 0;
164 
165 	rc = sprintf(buf, "%d\n", cap.owned);
166 	return rc;
167 }
168 static DEVICE_ATTR_RO(owned);
169 
170 static ssize_t temp_deactivated_show(struct device *dev,
171 				     struct device_attribute *attr, char *buf)
172 {
173 	cap_t cap;
174 	ssize_t rc;
175 
176 	rc = tpm_getcap(to_tpm_chip(dev), TPM_CAP_FLAG_VOL, &cap,
177 			"attempting to determine the temporary state",
178 			sizeof(cap.stclear_flags));
179 	if (rc)
180 		return 0;
181 
182 	rc = sprintf(buf, "%d\n", cap.stclear_flags.deactivated);
183 	return rc;
184 }
185 static DEVICE_ATTR_RO(temp_deactivated);
186 
187 static ssize_t caps_show(struct device *dev, struct device_attribute *attr,
188 			 char *buf)
189 {
190 	struct tpm_chip *chip = to_tpm_chip(dev);
191 	cap_t cap;
192 	ssize_t rc;
193 	char *str = buf;
194 
195 	rc = tpm_getcap(chip, TPM_CAP_PROP_MANUFACTURER, &cap,
196 			"attempting to determine the manufacturer",
197 			sizeof(cap.manufacturer_id));
198 	if (rc)
199 		return 0;
200 	str += sprintf(str, "Manufacturer: 0x%x\n",
201 		       be32_to_cpu(cap.manufacturer_id));
202 
203 	/* Try to get a TPM version 1.2 TPM_CAP_VERSION_INFO */
204 	rc = tpm_getcap(chip, TPM_CAP_VERSION_1_2, &cap,
205 			"attempting to determine the 1.2 version",
206 			sizeof(cap.tpm_version_1_2));
207 	if (!rc) {
208 		str += sprintf(str,
209 			       "TCG version: %d.%d\nFirmware version: %d.%d\n",
210 			       cap.tpm_version_1_2.Major,
211 			       cap.tpm_version_1_2.Minor,
212 			       cap.tpm_version_1_2.revMajor,
213 			       cap.tpm_version_1_2.revMinor);
214 	} else {
215 		/* Otherwise just use TPM_STRUCT_VER */
216 		rc = tpm_getcap(chip, TPM_CAP_VERSION_1_1, &cap,
217 				"attempting to determine the 1.1 version",
218 				sizeof(cap.tpm_version));
219 		if (rc)
220 			return 0;
221 		str += sprintf(str,
222 			       "TCG version: %d.%d\nFirmware version: %d.%d\n",
223 			       cap.tpm_version.Major,
224 			       cap.tpm_version.Minor,
225 			       cap.tpm_version.revMajor,
226 			       cap.tpm_version.revMinor);
227 	}
228 
229 	return str - buf;
230 }
231 static DEVICE_ATTR_RO(caps);
232 
233 static ssize_t cancel_store(struct device *dev, struct device_attribute *attr,
234 			    const char *buf, size_t count)
235 {
236 	struct tpm_chip *chip = to_tpm_chip(dev);
237 	if (chip == NULL)
238 		return 0;
239 
240 	chip->ops->cancel(chip);
241 	return count;
242 }
243 static DEVICE_ATTR_WO(cancel);
244 
245 static ssize_t durations_show(struct device *dev, struct device_attribute *attr,
246 			      char *buf)
247 {
248 	struct tpm_chip *chip = to_tpm_chip(dev);
249 
250 	if (chip->duration[TPM_LONG] == 0)
251 		return 0;
252 
253 	return sprintf(buf, "%d %d %d [%s]\n",
254 		       jiffies_to_usecs(chip->duration[TPM_SHORT]),
255 		       jiffies_to_usecs(chip->duration[TPM_MEDIUM]),
256 		       jiffies_to_usecs(chip->duration[TPM_LONG]),
257 		       chip->duration_adjusted
258 		       ? "adjusted" : "original");
259 }
260 static DEVICE_ATTR_RO(durations);
261 
262 static ssize_t timeouts_show(struct device *dev, struct device_attribute *attr,
263 			     char *buf)
264 {
265 	struct tpm_chip *chip = to_tpm_chip(dev);
266 
267 	return sprintf(buf, "%d %d %d %d [%s]\n",
268 		       jiffies_to_usecs(chip->timeout_a),
269 		       jiffies_to_usecs(chip->timeout_b),
270 		       jiffies_to_usecs(chip->timeout_c),
271 		       jiffies_to_usecs(chip->timeout_d),
272 		       chip->timeout_adjusted
273 		       ? "adjusted" : "original");
274 }
275 static DEVICE_ATTR_RO(timeouts);
276 
277 static struct attribute *tpm_dev_attrs[] = {
278 	&dev_attr_pubek.attr,
279 	&dev_attr_pcrs.attr,
280 	&dev_attr_enabled.attr,
281 	&dev_attr_active.attr,
282 	&dev_attr_owned.attr,
283 	&dev_attr_temp_deactivated.attr,
284 	&dev_attr_caps.attr,
285 	&dev_attr_cancel.attr,
286 	&dev_attr_durations.attr,
287 	&dev_attr_timeouts.attr,
288 	NULL,
289 };
290 
291 static const struct attribute_group tpm_dev_group = {
292 	.attrs = tpm_dev_attrs,
293 };
294 
295 void tpm_sysfs_add_device(struct tpm_chip *chip)
296 {
297 	if (chip->flags & TPM_CHIP_FLAG_TPM2)
298 		return;
299 
300 	/* The sysfs routines rely on an implicit tpm_try_get_ops, device_del
301 	 * is called before ops is null'd and the sysfs core synchronizes this
302 	 * removal so that no callbacks are running or can run again
303 	 */
304 	WARN_ON(chip->groups_cnt != 0);
305 	chip->groups[chip->groups_cnt++] = &tpm_dev_group;
306 }
307