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path: root/drivers/char/tpm/tpm-interface.c
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Diffstat (limited to 'drivers/char/tpm/tpm-interface.c')
-rw-r--r--drivers/char/tpm/tpm-interface.c58
1 files changed, 7 insertions, 51 deletions
diff --git a/drivers/char/tpm/tpm-interface.c b/drivers/char/tpm/tpm-interface.c
index a94a88f9f91c..a2205f26c74c 100644
--- a/drivers/char/tpm/tpm-interface.c
+++ b/drivers/char/tpm/tpm-interface.c
@@ -811,14 +811,6 @@ int tpm_pm_resume(struct device *dev)
}
EXPORT_SYMBOL_GPL(tpm_pm_resume);
-#define TPM_ORD_GET_RANDOM 70
-#define TPM_GETRANDOM_RESULT_SIZE 18
-static const struct tpm_input_header tpm_getrandom_header = {
- .tag = cpu_to_be16(TPM_TAG_RQU_COMMAND),
- .length = cpu_to_be32(14),
- .ordinal = cpu_to_be32(TPM_ORD_GET_RANDOM)
-};
-
/**
* tpm_get_random() - get random bytes from the TPM's RNG
* @chip: a &struct tpm_chip instance, %NULL for the default chip
@@ -829,58 +821,22 @@ static const struct tpm_input_header tpm_getrandom_header = {
*/
int tpm_get_random(struct tpm_chip *chip, u8 *out, size_t max)
{
- struct tpm_cmd_t tpm_cmd;
- u32 recd, num_bytes = min_t(u32, max, TPM_MAX_RNG_DATA), rlength;
- int err, total = 0, retries = 5;
- u8 *dest = out;
+ int rc;
- if (!out || !num_bytes || max > TPM_MAX_RNG_DATA)
+ if (!out || max > TPM_MAX_RNG_DATA)
return -EINVAL;
chip = tpm_find_get_ops(chip);
if (!chip)
return -ENODEV;
- if (chip->flags & TPM_CHIP_FLAG_TPM2) {
- err = tpm2_get_random(chip, out, max);
- tpm_put_ops(chip);
- return err;
- }
-
- do {
- tpm_cmd.header.in = tpm_getrandom_header;
- tpm_cmd.params.getrandom_in.num_bytes = cpu_to_be32(num_bytes);
-
- err = tpm_transmit_cmd(chip, NULL, &tpm_cmd,
- TPM_GETRANDOM_RESULT_SIZE + num_bytes,
- offsetof(struct tpm_getrandom_out,
- rng_data),
- 0, "attempting get random");
- if (err)
- break;
-
- recd = be32_to_cpu(tpm_cmd.params.getrandom_out.rng_data_len);
- if (recd > num_bytes) {
- total = -EFAULT;
- break;
- }
-
- rlength = be32_to_cpu(tpm_cmd.header.out.length);
- if (rlength < TPM_HEADER_SIZE +
- offsetof(struct tpm_getrandom_out, rng_data) +
- recd) {
- total = -EFAULT;
- break;
- }
- memcpy(dest, tpm_cmd.params.getrandom_out.rng_data, recd);
-
- dest += recd;
- total += recd;
- num_bytes -= recd;
- } while (retries-- && total < max);
+ if (chip->flags & TPM_CHIP_FLAG_TPM2)
+ rc = tpm2_get_random(chip, out, max);
+ else
+ rc = tpm1_get_random(chip, out, max);
tpm_put_ops(chip);
- return total ? total : -EIO;
+ return rc;
}
EXPORT_SYMBOL_GPL(tpm_get_random);