xref: /openbmc/linux/drivers/char/tpm/eventlog/tpm1.c (revision d9fd5a71)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * Copyright (C) 2005, 2012 IBM Corporation
4  *
5  * Authors:
6  *	Kent Yoder <key@linux.vnet.ibm.com>
7  *	Seiji Munetoh <munetoh@jp.ibm.com>
8  *	Stefan Berger <stefanb@us.ibm.com>
9  *	Reiner Sailer <sailer@watson.ibm.com>
10  *	Kylene Hall <kjhall@us.ibm.com>
11  *	Nayna Jain <nayna@linux.vnet.ibm.com>
12  *
13  * Maintained by: <tpmdd-devel@lists.sourceforge.net>
14  *
15  * Access to the event log created by a system's firmware / BIOS
16  */
17 
18 #include <linux/seq_file.h>
19 #include <linux/efi.h>
20 #include <linux/fs.h>
21 #include <linux/security.h>
22 #include <linux/module.h>
23 #include <linux/slab.h>
24 #include <linux/tpm_eventlog.h>
25 
26 #include "../tpm.h"
27 #include "common.h"
28 
29 
30 static const char* tcpa_event_type_strings[] = {
31 	"PREBOOT",
32 	"POST CODE",
33 	"",
34 	"NO ACTION",
35 	"SEPARATOR",
36 	"ACTION",
37 	"EVENT TAG",
38 	"S-CRTM Contents",
39 	"S-CRTM Version",
40 	"CPU Microcode",
41 	"Platform Config Flags",
42 	"Table of Devices",
43 	"Compact Hash",
44 	"IPL",
45 	"IPL Partition Data",
46 	"Non-Host Code",
47 	"Non-Host Config",
48 	"Non-Host Info"
49 };
50 
51 static const char* tcpa_pc_event_id_strings[] = {
52 	"",
53 	"SMBIOS",
54 	"BIS Certificate",
55 	"POST BIOS ",
56 	"ESCD ",
57 	"CMOS",
58 	"NVRAM",
59 	"Option ROM",
60 	"Option ROM config",
61 	"",
62 	"Option ROM microcode ",
63 	"S-CRTM Version",
64 	"S-CRTM Contents ",
65 	"POST Contents ",
66 	"Table of Devices",
67 };
68 
69 /* returns pointer to start of pos. entry of tcg log */
70 static void *tpm1_bios_measurements_start(struct seq_file *m, loff_t *pos)
71 {
72 	loff_t i = 0;
73 	struct tpm_chip *chip = m->private;
74 	struct tpm_bios_log *log = &chip->log;
75 	void *addr = log->bios_event_log;
76 	void *limit = log->bios_event_log_end;
77 	struct tcpa_event *event;
78 	u32 converted_event_size;
79 	u32 converted_event_type;
80 
81 	/* read over *pos measurements */
82 	do {
83 		event = addr;
84 
85 		/* check if current entry is valid */
86 		if (addr + sizeof(struct tcpa_event) > limit)
87 			return NULL;
88 
89 		converted_event_size =
90 		    do_endian_conversion(event->event_size);
91 		converted_event_type =
92 		    do_endian_conversion(event->event_type);
93 
94 		if (((converted_event_type == 0) && (converted_event_size == 0))
95 		    || ((addr + sizeof(struct tcpa_event) + converted_event_size)
96 			> limit))
97 			return NULL;
98 
99 		if (i++ == *pos)
100 			break;
101 
102 		addr += (sizeof(struct tcpa_event) + converted_event_size);
103 	} while (1);
104 
105 	return addr;
106 }
107 
108 static void *tpm1_bios_measurements_next(struct seq_file *m, void *v,
109 					loff_t *pos)
110 {
111 	struct tcpa_event *event = v;
112 	struct tpm_chip *chip = m->private;
113 	struct tpm_bios_log *log = &chip->log;
114 	void *limit = log->bios_event_log_end;
115 	u32 converted_event_size;
116 	u32 converted_event_type;
117 
118 	(*pos)++;
119 	converted_event_size = do_endian_conversion(event->event_size);
120 
121 	v += sizeof(struct tcpa_event) + converted_event_size;
122 
123 	/* now check if current entry is valid */
124 	if ((v + sizeof(struct tcpa_event)) > limit)
125 		return NULL;
126 
127 	event = v;
128 
129 	converted_event_size = do_endian_conversion(event->event_size);
130 	converted_event_type = do_endian_conversion(event->event_type);
131 
132 	if (((converted_event_type == 0) && (converted_event_size == 0)) ||
133 	    ((v + sizeof(struct tcpa_event) + converted_event_size) > limit))
134 		return NULL;
135 
136 	return v;
137 }
138 
139 static void tpm1_bios_measurements_stop(struct seq_file *m, void *v)
140 {
141 }
142 
143 static int get_event_name(char *dest, struct tcpa_event *event,
144 			unsigned char * event_entry)
145 {
146 	const char *name = "";
147 	/* 41 so there is room for 40 data and 1 nul */
148 	char data[41] = "";
149 	int i, n_len = 0, d_len = 0;
150 	struct tcpa_pc_event *pc_event;
151 
152 	switch (do_endian_conversion(event->event_type)) {
153 	case PREBOOT:
154 	case POST_CODE:
155 	case UNUSED:
156 	case NO_ACTION:
157 	case SCRTM_CONTENTS:
158 	case SCRTM_VERSION:
159 	case CPU_MICROCODE:
160 	case PLATFORM_CONFIG_FLAGS:
161 	case TABLE_OF_DEVICES:
162 	case COMPACT_HASH:
163 	case IPL:
164 	case IPL_PARTITION_DATA:
165 	case NONHOST_CODE:
166 	case NONHOST_CONFIG:
167 	case NONHOST_INFO:
168 		name = tcpa_event_type_strings[do_endian_conversion
169 						(event->event_type)];
170 		n_len = strlen(name);
171 		break;
172 	case SEPARATOR:
173 	case ACTION:
174 		if (MAX_TEXT_EVENT >
175 		    do_endian_conversion(event->event_size)) {
176 			name = event_entry;
177 			n_len = do_endian_conversion(event->event_size);
178 		}
179 		break;
180 	case EVENT_TAG:
181 		pc_event = (struct tcpa_pc_event *)event_entry;
182 
183 		/* ToDo Row data -> Base64 */
184 
185 		switch (do_endian_conversion(pc_event->event_id)) {
186 		case SMBIOS:
187 		case BIS_CERT:
188 		case CMOS:
189 		case NVRAM:
190 		case OPTION_ROM_EXEC:
191 		case OPTION_ROM_CONFIG:
192 		case S_CRTM_VERSION:
193 			name = tcpa_pc_event_id_strings[do_endian_conversion
194 							(pc_event->event_id)];
195 			n_len = strlen(name);
196 			break;
197 		/* hash data */
198 		case POST_BIOS_ROM:
199 		case ESCD:
200 		case OPTION_ROM_MICROCODE:
201 		case S_CRTM_CONTENTS:
202 		case POST_CONTENTS:
203 			name = tcpa_pc_event_id_strings[do_endian_conversion
204 							(pc_event->event_id)];
205 			n_len = strlen(name);
206 			for (i = 0; i < 20; i++)
207 				d_len += sprintf(&data[2*i], "%02x",
208 						pc_event->event_data[i]);
209 			break;
210 		default:
211 			break;
212 		}
213 		break;
214 	default:
215 		break;
216 	}
217 
218 	return snprintf(dest, MAX_TEXT_EVENT, "[%.*s%.*s]",
219 			n_len, name, d_len, data);
220 
221 }
222 
223 static int tpm1_binary_bios_measurements_show(struct seq_file *m, void *v)
224 {
225 	struct tcpa_event *event = v;
226 	struct tcpa_event temp_event;
227 	char *temp_ptr;
228 	int i;
229 
230 	memcpy(&temp_event, event, sizeof(struct tcpa_event));
231 
232 	/* convert raw integers for endianness */
233 	temp_event.pcr_index = do_endian_conversion(event->pcr_index);
234 	temp_event.event_type = do_endian_conversion(event->event_type);
235 	temp_event.event_size = do_endian_conversion(event->event_size);
236 
237 	temp_ptr = (char *) &temp_event;
238 
239 	for (i = 0; i < (sizeof(struct tcpa_event) - 1) ; i++)
240 		seq_putc(m, temp_ptr[i]);
241 
242 	temp_ptr = (char *) v;
243 
244 	for (i = (sizeof(struct tcpa_event) - 1);
245 	     i < (sizeof(struct tcpa_event) + temp_event.event_size); i++)
246 		seq_putc(m, temp_ptr[i]);
247 
248 	return 0;
249 
250 }
251 
252 static int tpm1_ascii_bios_measurements_show(struct seq_file *m, void *v)
253 {
254 	int len = 0;
255 	char *eventname;
256 	struct tcpa_event *event = v;
257 	unsigned char *event_entry =
258 	    (unsigned char *)(v + sizeof(struct tcpa_event));
259 
260 	eventname = kmalloc(MAX_TEXT_EVENT, GFP_KERNEL);
261 	if (!eventname) {
262 		printk(KERN_ERR "%s: ERROR - No Memory for event name\n ",
263 		       __func__);
264 		return -EFAULT;
265 	}
266 
267 	/* 1st: PCR */
268 	seq_printf(m, "%2d ", do_endian_conversion(event->pcr_index));
269 
270 	/* 2nd: SHA1 */
271 	seq_printf(m, "%20phN", event->pcr_value);
272 
273 	/* 3rd: event type identifier */
274 	seq_printf(m, " %02x", do_endian_conversion(event->event_type));
275 
276 	len += get_event_name(eventname, event, event_entry);
277 
278 	/* 4th: eventname <= max + \'0' delimiter */
279 	seq_printf(m, " %s\n", eventname);
280 
281 	kfree(eventname);
282 	return 0;
283 }
284 
285 const struct seq_operations tpm1_ascii_b_measurements_seqops = {
286 	.start = tpm1_bios_measurements_start,
287 	.next = tpm1_bios_measurements_next,
288 	.stop = tpm1_bios_measurements_stop,
289 	.show = tpm1_ascii_bios_measurements_show,
290 };
291 
292 const struct seq_operations tpm1_binary_b_measurements_seqops = {
293 	.start = tpm1_bios_measurements_start,
294 	.next = tpm1_bios_measurements_next,
295 	.stop = tpm1_bios_measurements_stop,
296 	.show = tpm1_binary_bios_measurements_show,
297 };
298