lk/linux-kernel-test
1
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity

TPM: integrity interface

Browse Source 
This patch adds internal kernel support for:
 - reading/extending a pcr value
 - looking up the tpm_chip for a given chip number

Signed-off-by: Rajiv Andrade <srajiv@linux.vnet.ibm.com>
Signed-off-by: Mimi Zohar <zohar@us.ibm.com>
Signed-off-by: James Morris <jmorris@namei.org>
This commit is contained in:
Rajiv Andrade
2009-02-02 15:23:44 -02:00
committed by James Morris
parent 0883743825
commit 659aaf2bb5
3 changed files with 163 additions and 19 deletions
Download Patch File Download Diff File Expand all files Collapse all files

129
drivers/char/tpm/tpm.c
View File

@@ -661,28 +661,125 @@ ssize_t tpm_show_temp_deactivated(struct device * dev,
}
EXPORT_SYMBOL_GPL(tpm_show_temp_deactivated);
static const u8 pcrread[] = {
0, 193, /* TPM_TAG_RQU_COMMAND */
0, 0, 0, 14, /* length */
0, 0, 0, 21, /* TPM_ORD_PcrRead */
0, 0, 0, 0 /* PCR index */
/*
* tpm_chip_find_get - return tpm_chip for given chip number
*/
static struct tpm_chip *tpm_chip_find_get(int chip_num)
{
struct tpm_chip *pos;
rcu_read_lock();
list_for_each_entry_rcu(pos, &tpm_chip_list, list) {
if (chip_num != TPM_ANY_NUM && chip_num != pos->dev_num)
continue;
if (try_module_get(pos->dev->driver->owner))
break;
}
rcu_read_unlock();
return pos;
}
#define TPM_ORDINAL_PCRREAD cpu_to_be32(21)
#define READ_PCR_RESULT_SIZE 30
static struct tpm_input_header pcrread_header = {
.tag = TPM_TAG_RQU_COMMAND,
.length = cpu_to_be32(14),
.ordinal = TPM_ORDINAL_PCRREAD
};
int __tpm_pcr_read(struct tpm_chip *chip, int pcr_idx, u8 *res_buf)
{
int rc;
struct tpm_cmd_t cmd;
cmd.header.in = pcrread_header;
cmd.params.pcrread_in.pcr_idx = cpu_to_be32(pcr_idx);
BUILD_BUG_ON(cmd.header.in.length > READ_PCR_RESULT_SIZE);
rc = transmit_cmd(chip, &cmd, cmd.header.in.length,
"attempting to read a pcr value");
if (rc == 0)
memcpy(res_buf, cmd.params.pcrread_out.pcr_result,
TPM_DIGEST_SIZE);
return rc;
}
/**
* tpm_pcr_read - read a pcr value
* @chip_num: tpm idx # or ANY
* @pcr_idx: pcr idx to retrieve
* @res_buf: TPM_PCR value
* size of res_buf is 20 bytes (or NULL if you don't care)
*
* The TPM driver should be built-in, but for whatever reason it
* isn't, protect against the chip disappearing, by incrementing
* the module usage count.
*/
int tpm_pcr_read(u32 chip_num, int pcr_idx, u8 *res_buf)
{
struct tpm_chip *chip;
int rc;
chip = tpm_chip_find_get(chip_num);
if (chip == NULL)
return -ENODEV;
rc = __tpm_pcr_read(chip, pcr_idx, res_buf);
module_put(chip->dev->driver->owner);
return rc;
}
EXPORT_SYMBOL_GPL(tpm_pcr_read);
/**
* tpm_pcr_extend - extend pcr value with hash
* @chip_num: tpm idx # or AN&
* @pcr_idx: pcr idx to extend
* @hash: hash value used to extend pcr value
*
* The TPM driver should be built-in, but for whatever reason it
* isn't, protect against the chip disappearing, by incrementing
* the module usage count.
*/
#define TPM_ORD_PCR_EXTEND cpu_to_be32(20)
#define EXTEND_PCR_SIZE 34
static struct tpm_input_header pcrextend_header = {
.tag = TPM_TAG_RQU_COMMAND,
.length = cpu_to_be32(34),
.ordinal = TPM_ORD_PCR_EXTEND
};
int tpm_pcr_extend(u32 chip_num, int pcr_idx, const u8 *hash)
{
struct tpm_cmd_t cmd;
int rc;
struct tpm_chip *chip;
chip = tpm_chip_find_get(chip_num);
if (chip == NULL)
return -ENODEV;
cmd.header.in = pcrextend_header;
BUILD_BUG_ON(be32_to_cpu(cmd.header.in.length) > EXTEND_PCR_SIZE);
cmd.params.pcrextend_in.pcr_idx = cpu_to_be32(pcr_idx);
memcpy(cmd.params.pcrextend_in.hash, hash, TPM_DIGEST_SIZE);
rc = transmit_cmd(chip, &cmd, cmd.header.in.length,
"attempting extend a PCR value");
module_put(chip->dev->driver->owner);
return rc;
}
EXPORT_SYMBOL_GPL(tpm_pcr_extend);
ssize_t tpm_show_pcrs(struct device *dev, struct device_attribute *attr,
char *buf)
{
cap_t cap;
u8 *data;
u8 digest[TPM_DIGEST_SIZE];
ssize_t rc;
int i, j, num_pcrs;
__be32 index;
char *str = buf;
struct tpm_chip *chip = dev_get_drvdata(dev);
data = kzalloc(TPM_INTERNAL_RESULT_SIZE, GFP_KERNEL);
if (!data)
return -ENOMEM;
rc = tpm_getcap(dev, TPM_CAP_PROP_PCR, &cap,
"attempting to determine the number of PCRS");
if (rc)
@@ -690,20 +787,14 @@ ssize_t tpm_show_pcrs(struct device *dev, struct device_attribute *attr,
num_pcrs = be32_to_cpu(cap.num_pcrs);
for (i = 0; i < num_pcrs; i++) {
memcpy(data, pcrread, sizeof(pcrread));
index = cpu_to_be32(i);
memcpy(data + 10, &index, 4);
rc = transmit_cmd(chip, (struct tpm_cmd_t *)data,
TPM_INTERNAL_RESULT_SIZE,
"attempting to read a PCR");
rc = __tpm_pcr_read(chip, i, digest);
if (rc)
break;
str += sprintf(str, "PCR-%02d: ", i);
for (j = 0; j < TPM_DIGEST_SIZE; j++)
str += sprintf(str, "%02X ", *(data + 10 + j));
str += sprintf(str, "%02X ", digest[j]);
str += sprintf(str, "\n");
}
kfree(data);
return str - buf;
}
EXPORT_SYMBOL_GPL(tpm_show_pcrs);