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-rw-r--r--drivers/char/tpm/tpm.c59
-rw-r--r--drivers/char/tpm/tpm.h23
2 files changed, 76 insertions, 6 deletions
diff --git a/drivers/char/tpm/tpm.c b/drivers/char/tpm/tpm.c
index 677c6e26593f..36e43e50dcef 100644
--- a/drivers/char/tpm/tpm.c
+++ b/drivers/char/tpm/tpm.c
@@ -32,12 +32,6 @@
32#include "tpm.h" 32#include "tpm.h"
33#include "tpm_eventlog.h" 33#include "tpm_eventlog.h"
34 34
35enum tpm_const {
36 TPM_MINOR = 224, /* officially assigned */
37 TPM_BUFSIZE = 4096,
38 TPM_NUM_DEVICES = 256,
39};
40
41enum tpm_duration { 35enum tpm_duration {
42 TPM_SHORT = 0, 36 TPM_SHORT = 0,
43 TPM_MEDIUM = 1, 37 TPM_MEDIUM = 1,
@@ -483,6 +477,7 @@ static ssize_t transmit_cmd(struct tpm_chip *chip, struct tpm_cmd_t *cmd,
483#define TPM_INTERNAL_RESULT_SIZE 200 477#define TPM_INTERNAL_RESULT_SIZE 200
484#define TPM_TAG_RQU_COMMAND cpu_to_be16(193) 478#define TPM_TAG_RQU_COMMAND cpu_to_be16(193)
485#define TPM_ORD_GET_CAP cpu_to_be32(101) 479#define TPM_ORD_GET_CAP cpu_to_be32(101)
480#define TPM_ORD_GET_RANDOM cpu_to_be32(70)
486 481
487static const struct tpm_input_header tpm_getcap_header = { 482static const struct tpm_input_header tpm_getcap_header = {
488 .tag = TPM_TAG_RQU_COMMAND, 483 .tag = TPM_TAG_RQU_COMMAND,
@@ -1327,6 +1322,58 @@ int tpm_pm_resume(struct device *dev)
1327} 1322}
1328EXPORT_SYMBOL_GPL(tpm_pm_resume); 1323EXPORT_SYMBOL_GPL(tpm_pm_resume);
1329 1324
1325#define TPM_GETRANDOM_RESULT_SIZE 18
1326static struct tpm_input_header tpm_getrandom_header = {
1327 .tag = TPM_TAG_RQU_COMMAND,
1328 .length = cpu_to_be32(14),
1329 .ordinal = TPM_ORD_GET_RANDOM
1330};
1331
1332/**
1333 * tpm_get_random() - Get random bytes from the tpm's RNG
1334 * @chip_num: A specific chip number for the request or TPM_ANY_NUM
1335 * @out: destination buffer for the random bytes
1336 * @max: the max number of bytes to write to @out
1337 *
1338 * Returns < 0 on error and the number of bytes read on success
1339 */
1340int tpm_get_random(u32 chip_num, u8 *out, size_t max)
1341{
1342 struct tpm_chip *chip;
1343 struct tpm_cmd_t tpm_cmd;
1344 u32 recd, num_bytes = min_t(u32, max, TPM_MAX_RNG_DATA);
1345 int err, total = 0, retries = 5;
1346 u8 *dest = out;
1347
1348 chip = tpm_chip_find_get(chip_num);
1349 if (chip == NULL)
1350 return -ENODEV;
1351
1352 if (!out || !num_bytes || max > TPM_MAX_RNG_DATA)
1353 return -EINVAL;
1354
1355 do {
1356 tpm_cmd.header.in = tpm_getrandom_header;
1357 tpm_cmd.params.getrandom_in.num_bytes = cpu_to_be32(num_bytes);
1358
1359 err = transmit_cmd(chip, &tpm_cmd,
1360 TPM_GETRANDOM_RESULT_SIZE + num_bytes,
1361 "attempting get random");
1362 if (err)
1363 break;
1364
1365 recd = be32_to_cpu(tpm_cmd.params.getrandom_out.rng_data_len);
1366 memcpy(dest, tpm_cmd.params.getrandom_out.rng_data, recd);
1367
1368 dest += recd;
1369 total += recd;
1370 num_bytes -= recd;
1371 } while (retries-- && total < max);
1372
1373 return total ? total : -EIO;
1374}
1375EXPORT_SYMBOL_GPL(tpm_get_random);
1376
1330/* In case vendor provided release function, call it too.*/ 1377/* In case vendor provided release function, call it too.*/
1331 1378
1332void tpm_dev_vendor_release(struct tpm_chip *chip) 1379void tpm_dev_vendor_release(struct tpm_chip *chip)
diff --git a/drivers/char/tpm/tpm.h b/drivers/char/tpm/tpm.h
index 917f727e6740..645136eea890 100644
--- a/drivers/char/tpm/tpm.h
+++ b/drivers/char/tpm/tpm.h
@@ -28,6 +28,12 @@
28#include <linux/io.h> 28#include <linux/io.h>
29#include <linux/tpm.h> 29#include <linux/tpm.h>
30 30
31enum tpm_const {
32 TPM_MINOR = 224, /* officially assigned */
33 TPM_BUFSIZE = 4096,
34 TPM_NUM_DEVICES = 256,
35};
36
31enum tpm_timeout { 37enum tpm_timeout {
32 TPM_TIMEOUT = 5, /* msecs */ 38 TPM_TIMEOUT = 5, /* msecs */
33}; 39};
@@ -269,6 +275,21 @@ struct tpm_pcrextend_in {
269 u8 hash[TPM_DIGEST_SIZE]; 275 u8 hash[TPM_DIGEST_SIZE];
270}__attribute__((packed)); 276}__attribute__((packed));
271 277
278/* 128 bytes is an arbitrary cap. This could be as large as TPM_BUFSIZE - 18
279 * bytes, but 128 is still a relatively large number of random bytes and
280 * anything much bigger causes users of struct tpm_cmd_t to start getting
281 * compiler warnings about stack frame size. */
282#define TPM_MAX_RNG_DATA 128
283
284struct tpm_getrandom_out {
285 __be32 rng_data_len;
286 u8 rng_data[TPM_MAX_RNG_DATA];
287}__attribute__((packed));
288
289struct tpm_getrandom_in {
290 __be32 num_bytes;
291}__attribute__((packed));
292
272typedef union { 293typedef union {
273 struct tpm_getcap_params_out getcap_out; 294 struct tpm_getcap_params_out getcap_out;
274 struct tpm_readpubek_params_out readpubek_out; 295 struct tpm_readpubek_params_out readpubek_out;
@@ -277,6 +298,8 @@ typedef union {
277 struct tpm_pcrread_in pcrread_in; 298 struct tpm_pcrread_in pcrread_in;
278 struct tpm_pcrread_out pcrread_out; 299 struct tpm_pcrread_out pcrread_out;
279 struct tpm_pcrextend_in pcrextend_in; 300 struct tpm_pcrextend_in pcrextend_in;
301 struct tpm_getrandom_in getrandom_in;
302 struct tpm_getrandom_out getrandom_out;
280} tpm_cmd_params; 303} tpm_cmd_params;
281 304
282struct tpm_cmd_t { 305struct tpm_cmd_t {