Commit ce63c05b authored by Jarkko Sakkinen's avatar Jarkko Sakkinen

tpm: migrate tpm2_get_random() to use struct tpm_buf

In order to make struct tpm_buf the first class object for constructing
TPM commands, migrate tpm2_get_random() to use it. In addition, removed
remaining references to struct tpm2_cmd. All of them use it to acquire
the length of the response, which can be achieved by using
tpm_buf_length().
Signed-off-by: default avatarJarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Tested-by: Nayna Jain<nayna@linux.vnet.ibm.com>
parent 2ab32411
......@@ -424,23 +424,24 @@ struct tpm_buf {
u8 *data;
};
static inline int tpm_buf_init(struct tpm_buf *buf, u16 tag, u32 ordinal)
static inline void tpm_buf_reset(struct tpm_buf *buf, u16 tag, u32 ordinal)
{
struct tpm_input_header *head;
head = (struct tpm_input_header *)buf->data;
head->tag = cpu_to_be16(tag);
head->length = cpu_to_be32(sizeof(*head));
head->ordinal = cpu_to_be32(ordinal);
}
static inline int tpm_buf_init(struct tpm_buf *buf, u16 tag, u32 ordinal)
{
buf->data_page = alloc_page(GFP_HIGHUSER);
if (!buf->data_page)
return -ENOMEM;
buf->flags = 0;
buf->data = kmap(buf->data_page);
head = (struct tpm_input_header *) buf->data;
head->tag = cpu_to_be16(tag);
head->length = cpu_to_be32(sizeof(*head));
head->ordinal = cpu_to_be32(ordinal);
tpm_buf_reset(buf, tag, ordinal);
return 0;
}
......@@ -569,7 +570,7 @@ static inline u32 tpm2_rc_value(u32 rc)
int tpm2_pcr_read(struct tpm_chip *chip, int pcr_idx, u8 *res_buf);
int tpm2_pcr_extend(struct tpm_chip *chip, int pcr_idx, u32 count,
struct tpm2_digest *digests);
int tpm2_get_random(struct tpm_chip *chip, u8 *out, size_t max);
int tpm2_get_random(struct tpm_chip *chip, u8 *dest, size_t max);
void tpm2_flush_context_cmd(struct tpm_chip *chip, u32 handle,
unsigned int flags);
int tpm2_seal_trusted(struct tpm_chip *chip,
......
......@@ -27,25 +27,6 @@ enum tpm2_session_attributes {
TPM2_SA_CONTINUE_SESSION = BIT(0),
};
struct tpm2_get_random_in {
__be16 size;
} __packed;
struct tpm2_get_random_out {
__be16 size;
u8 buffer[TPM_MAX_RNG_DATA];
} __packed;
union tpm2_cmd_params {
struct tpm2_get_random_in getrandom_in;
struct tpm2_get_random_out getrandom_out;
};
struct tpm2_cmd {
tpm_cmd_header header;
union tpm2_cmd_params params;
} __packed;
struct tpm2_hash {
unsigned int crypto_id;
unsigned int tpm_id;
......@@ -300,67 +281,70 @@ int tpm2_pcr_extend(struct tpm_chip *chip, int pcr_idx, u32 count,
}
#define TPM2_GETRANDOM_IN_SIZE \
(sizeof(struct tpm_input_header) + \
sizeof(struct tpm2_get_random_in))
static const struct tpm_input_header tpm2_getrandom_header = {
.tag = cpu_to_be16(TPM2_ST_NO_SESSIONS),
.length = cpu_to_be32(TPM2_GETRANDOM_IN_SIZE),
.ordinal = cpu_to_be32(TPM2_CC_GET_RANDOM)
};
struct tpm2_get_random_out {
__be16 size;
u8 buffer[TPM_MAX_RNG_DATA];
} __packed;
/**
* tpm2_get_random() - get random bytes from the TPM RNG
*
* @chip: TPM chip to use
* @out: destination buffer for the random bytes
* @max: the max number of bytes to write to @out
* @chip: a &tpm_chip instance
* @dest: destination buffer
* @max: the max number of random bytes to pull
*
* Return:
* Size of the output buffer, or -EIO on error.
* size of the buffer on success,
* -errno otherwise
*/
int tpm2_get_random(struct tpm_chip *chip, u8 *out, size_t max)
int tpm2_get_random(struct tpm_chip *chip, u8 *dest, size_t max)
{
struct tpm2_cmd cmd;
u32 recd, rlength;
u32 num_bytes;
struct tpm2_get_random_out *out;
struct tpm_buf buf;
u32 recd;
u32 num_bytes = max;
int err;
int total = 0;
int retries = 5;
u8 *dest = out;
num_bytes = min_t(u32, max, sizeof(cmd.params.getrandom_out.buffer));
u8 *dest_ptr = dest;
if (!out || !num_bytes ||
max > sizeof(cmd.params.getrandom_out.buffer))
if (!num_bytes || max > TPM_MAX_RNG_DATA)
return -EINVAL;
do {
cmd.header.in = tpm2_getrandom_header;
cmd.params.getrandom_in.size = cpu_to_be16(num_bytes);
err = tpm_buf_init(&buf, 0, 0);
if (err)
return err;
err = tpm_transmit_cmd(chip, NULL, &cmd, sizeof(cmd),
do {
tpm_buf_reset(&buf, TPM2_ST_NO_SESSIONS, TPM2_CC_GET_RANDOM);
tpm_buf_append_u16(&buf, num_bytes);
err = tpm_transmit_cmd(chip, NULL, buf.data, PAGE_SIZE,
offsetof(struct tpm2_get_random_out,
buffer),
0, "attempting get random");
if (err)
break;
goto out;
recd = min_t(u32, be16_to_cpu(cmd.params.getrandom_out.size),
num_bytes);
rlength = be32_to_cpu(cmd.header.out.length);
if (rlength < offsetof(struct tpm2_get_random_out, buffer) +
recd)
return -EFAULT;
memcpy(dest, cmd.params.getrandom_out.buffer, recd);
out = (struct tpm2_get_random_out *)
&buf.data[TPM_HEADER_SIZE];
recd = min_t(u32, be16_to_cpu(out->size), num_bytes);
if (tpm_buf_length(&buf) <
offsetof(struct tpm2_get_random_out, buffer) + recd) {
err = -EFAULT;
goto out;
}
memcpy(dest_ptr, out->buffer, recd);
dest += recd;
dest_ptr += recd;
total += recd;
num_bytes -= recd;
} while (retries-- && total < max);
tpm_buf_destroy(&buf);
return total ? total : -EIO;
out:
tpm_buf_destroy(&buf);
return err;
}
/**
......@@ -437,7 +421,7 @@ int tpm2_seal_trusted(struct tpm_chip *chip,
{
unsigned int blob_len;
struct tpm_buf buf;
u32 hash, rlength;
u32 hash;
int i;
int rc;
......@@ -512,8 +496,7 @@ int tpm2_seal_trusted(struct tpm_chip *chip,
rc = -E2BIG;
goto out;
}
rlength = be32_to_cpu(((struct tpm2_cmd *)&buf)->header.out.length);
if (rlength < TPM_HEADER_SIZE + 4 + blob_len) {
if (tpm_buf_length(&buf) < TPM_HEADER_SIZE + 4 + blob_len) {
rc = -EFAULT;
goto out;
}
......@@ -623,7 +606,6 @@ static int tpm2_unseal_cmd(struct tpm_chip *chip,
u16 data_len;
u8 *data;
int rc;
u32 rlength;
rc = tpm_buf_init(&buf, TPM2_ST_SESSIONS, TPM2_CC_UNSEAL);
if (rc)
......@@ -651,9 +633,7 @@ static int tpm2_unseal_cmd(struct tpm_chip *chip,
goto out;
}
rlength = be32_to_cpu(((struct tpm2_cmd *)&buf)
->header.out.length);
if (rlength < TPM_HEADER_SIZE + 6 + data_len) {
if (tpm_buf_length(&buf) < TPM_HEADER_SIZE + 6 + data_len) {
rc = -EFAULT;
goto out;
}
......
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