xref: /openbmc/linux/drivers/char/tpm/tpm-sysfs.c (revision 77a87824)
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 TPM_ORD_READPUBEK cpu_to_be32(124)
25 static struct tpm_input_header tpm_readpubek_header = {
26 	.tag = TPM_TAG_RQU_COMMAND,
27 	.length = cpu_to_be32(30),
28 	.ordinal = TPM_ORD_READPUBEK
29 };
30 static ssize_t pubek_show(struct device *dev, struct device_attribute *attr,
31 			  char *buf)
32 {
33 	u8 *data;
34 	struct tpm_cmd_t tpm_cmd;
35 	ssize_t err;
36 	int i, rc;
37 	char *str = buf;
38 
39 	struct tpm_chip *chip = to_tpm_chip(dev);
40 
41 	tpm_cmd.header.in = tpm_readpubek_header;
42 	err = tpm_transmit_cmd(chip, &tpm_cmd, READ_PUBEK_RESULT_SIZE,
43 			       "attempting to read the PUBEK");
44 	if (err)
45 		goto out;
46 
47 	/*
48 	   ignore header 10 bytes
49 	   algorithm 32 bits (1 == RSA )
50 	   encscheme 16 bits
51 	   sigscheme 16 bits
52 	   parameters (RSA 12->bytes: keybit, #primes, expbit)
53 	   keylenbytes 32 bits
54 	   256 byte modulus
55 	   ignore checksum 20 bytes
56 	 */
57 	data = tpm_cmd.params.readpubek_out_buffer;
58 	str +=
59 	    sprintf(str,
60 		    "Algorithm: %02X %02X %02X %02X\n"
61 		    "Encscheme: %02X %02X\n"
62 		    "Sigscheme: %02X %02X\n"
63 		    "Parameters: %02X %02X %02X %02X "
64 		    "%02X %02X %02X %02X "
65 		    "%02X %02X %02X %02X\n"
66 		    "Modulus length: %d\n"
67 		    "Modulus:\n",
68 		    data[0], data[1], data[2], data[3],
69 		    data[4], data[5],
70 		    data[6], data[7],
71 		    data[12], data[13], data[14], data[15],
72 		    data[16], data[17], data[18], data[19],
73 		    data[20], data[21], data[22], data[23],
74 		    be32_to_cpu(*((__be32 *) (data + 24))));
75 
76 	for (i = 0; i < 256; i++) {
77 		str += sprintf(str, "%02X ", data[i + 28]);
78 		if ((i + 1) % 16 == 0)
79 			str += sprintf(str, "\n");
80 	}
81 out:
82 	rc = str - buf;
83 	return rc;
84 }
85 static DEVICE_ATTR_RO(pubek);
86 
87 static ssize_t pcrs_show(struct device *dev, struct device_attribute *attr,
88 			 char *buf)
89 {
90 	cap_t cap;
91 	u8 digest[TPM_DIGEST_SIZE];
92 	ssize_t rc;
93 	int i, j, num_pcrs;
94 	char *str = buf;
95 	struct tpm_chip *chip = to_tpm_chip(dev);
96 
97 	rc = tpm_getcap(chip, TPM_CAP_PROP_PCR, &cap,
98 			"attempting to determine the number of PCRS");
99 	if (rc)
100 		return 0;
101 
102 	num_pcrs = be32_to_cpu(cap.num_pcrs);
103 	for (i = 0; i < num_pcrs; i++) {
104 		rc = tpm_pcr_read_dev(chip, i, digest);
105 		if (rc)
106 			break;
107 		str += sprintf(str, "PCR-%02d: ", i);
108 		for (j = 0; j < TPM_DIGEST_SIZE; j++)
109 			str += sprintf(str, "%02X ", digest[j]);
110 		str += sprintf(str, "\n");
111 	}
112 	return str - buf;
113 }
114 static DEVICE_ATTR_RO(pcrs);
115 
116 static ssize_t enabled_show(struct device *dev, struct device_attribute *attr,
117 		     char *buf)
118 {
119 	cap_t cap;
120 	ssize_t rc;
121 
122 	rc = tpm_getcap(to_tpm_chip(dev), TPM_CAP_FLAG_PERM, &cap,
123 			"attempting to determine the permanent enabled state");
124 	if (rc)
125 		return 0;
126 
127 	rc = sprintf(buf, "%d\n", !cap.perm_flags.disable);
128 	return rc;
129 }
130 static DEVICE_ATTR_RO(enabled);
131 
132 static ssize_t active_show(struct device *dev, struct device_attribute *attr,
133 		    char *buf)
134 {
135 	cap_t cap;
136 	ssize_t rc;
137 
138 	rc = tpm_getcap(to_tpm_chip(dev), TPM_CAP_FLAG_PERM, &cap,
139 			"attempting to determine the permanent active state");
140 	if (rc)
141 		return 0;
142 
143 	rc = sprintf(buf, "%d\n", !cap.perm_flags.deactivated);
144 	return rc;
145 }
146 static DEVICE_ATTR_RO(active);
147 
148 static ssize_t owned_show(struct device *dev, struct device_attribute *attr,
149 			  char *buf)
150 {
151 	cap_t cap;
152 	ssize_t rc;
153 
154 	rc = tpm_getcap(to_tpm_chip(dev), TPM_CAP_PROP_OWNER, &cap,
155 			"attempting to determine the owner state");
156 	if (rc)
157 		return 0;
158 
159 	rc = sprintf(buf, "%d\n", cap.owned);
160 	return rc;
161 }
162 static DEVICE_ATTR_RO(owned);
163 
164 static ssize_t temp_deactivated_show(struct device *dev,
165 				     struct device_attribute *attr, char *buf)
166 {
167 	cap_t cap;
168 	ssize_t rc;
169 
170 	rc = tpm_getcap(to_tpm_chip(dev), TPM_CAP_FLAG_VOL, &cap,
171 			"attempting to determine the temporary state");
172 	if (rc)
173 		return 0;
174 
175 	rc = sprintf(buf, "%d\n", cap.stclear_flags.deactivated);
176 	return rc;
177 }
178 static DEVICE_ATTR_RO(temp_deactivated);
179 
180 static ssize_t caps_show(struct device *dev, struct device_attribute *attr,
181 			 char *buf)
182 {
183 	struct tpm_chip *chip = to_tpm_chip(dev);
184 	cap_t cap;
185 	ssize_t rc;
186 	char *str = buf;
187 
188 	rc = tpm_getcap(chip, TPM_CAP_PROP_MANUFACTURER, &cap,
189 			"attempting to determine the manufacturer");
190 	if (rc)
191 		return 0;
192 	str += sprintf(str, "Manufacturer: 0x%x\n",
193 		       be32_to_cpu(cap.manufacturer_id));
194 
195 	/* Try to get a TPM version 1.2 TPM_CAP_VERSION_INFO */
196 	rc = tpm_getcap(chip, CAP_VERSION_1_2, &cap,
197 			"attempting to determine the 1.2 version");
198 	if (!rc) {
199 		str += sprintf(str,
200 			       "TCG version: %d.%d\nFirmware version: %d.%d\n",
201 			       cap.tpm_version_1_2.Major,
202 			       cap.tpm_version_1_2.Minor,
203 			       cap.tpm_version_1_2.revMajor,
204 			       cap.tpm_version_1_2.revMinor);
205 	} else {
206 		/* Otherwise just use TPM_STRUCT_VER */
207 		rc = tpm_getcap(chip, CAP_VERSION_1_1, &cap,
208 				"attempting to determine the 1.1 version");
209 		if (rc)
210 			return 0;
211 		str += sprintf(str,
212 			       "TCG version: %d.%d\nFirmware version: %d.%d\n",
213 			       cap.tpm_version.Major,
214 			       cap.tpm_version.Minor,
215 			       cap.tpm_version.revMajor,
216 			       cap.tpm_version.revMinor);
217 	}
218 
219 	return str - buf;
220 }
221 static DEVICE_ATTR_RO(caps);
222 
223 static ssize_t cancel_store(struct device *dev, struct device_attribute *attr,
224 			    const char *buf, size_t count)
225 {
226 	struct tpm_chip *chip = to_tpm_chip(dev);
227 	if (chip == NULL)
228 		return 0;
229 
230 	chip->ops->cancel(chip);
231 	return count;
232 }
233 static DEVICE_ATTR_WO(cancel);
234 
235 static ssize_t durations_show(struct device *dev, struct device_attribute *attr,
236 			      char *buf)
237 {
238 	struct tpm_chip *chip = to_tpm_chip(dev);
239 
240 	if (chip->duration[TPM_LONG] == 0)
241 		return 0;
242 
243 	return sprintf(buf, "%d %d %d [%s]\n",
244 		       jiffies_to_usecs(chip->duration[TPM_SHORT]),
245 		       jiffies_to_usecs(chip->duration[TPM_MEDIUM]),
246 		       jiffies_to_usecs(chip->duration[TPM_LONG]),
247 		       chip->duration_adjusted
248 		       ? "adjusted" : "original");
249 }
250 static DEVICE_ATTR_RO(durations);
251 
252 static ssize_t timeouts_show(struct device *dev, struct device_attribute *attr,
253 			     char *buf)
254 {
255 	struct tpm_chip *chip = to_tpm_chip(dev);
256 
257 	return sprintf(buf, "%d %d %d %d [%s]\n",
258 		       jiffies_to_usecs(chip->timeout_a),
259 		       jiffies_to_usecs(chip->timeout_b),
260 		       jiffies_to_usecs(chip->timeout_c),
261 		       jiffies_to_usecs(chip->timeout_d),
262 		       chip->timeout_adjusted
263 		       ? "adjusted" : "original");
264 }
265 static DEVICE_ATTR_RO(timeouts);
266 
267 static struct attribute *tpm_dev_attrs[] = {
268 	&dev_attr_pubek.attr,
269 	&dev_attr_pcrs.attr,
270 	&dev_attr_enabled.attr,
271 	&dev_attr_active.attr,
272 	&dev_attr_owned.attr,
273 	&dev_attr_temp_deactivated.attr,
274 	&dev_attr_caps.attr,
275 	&dev_attr_cancel.attr,
276 	&dev_attr_durations.attr,
277 	&dev_attr_timeouts.attr,
278 	NULL,
279 };
280 
281 static const struct attribute_group tpm_dev_group = {
282 	.attrs = tpm_dev_attrs,
283 };
284 
285 void tpm_sysfs_add_device(struct tpm_chip *chip)
286 {
287 	/* The sysfs routines rely on an implicit tpm_try_get_ops, device_del
288 	 * is called before ops is null'd and the sysfs core synchronizes this
289 	 * removal so that no callbacks are running or can run again
290 	 */
291 	WARN_ON(chip->groups_cnt != 0);
292 	chip->groups[chip->groups_cnt++] = &tpm_dev_group;
293 }
294