Commit 40813f18 authored by Jarkko Sakkinen's avatar Jarkko Sakkinen
Browse files

KEYS: trusted: tpm2: Use struct tpm_buf for sized buffers 



Take advantage of the new sized buffer (TPM2B) mode of struct tpm_buf in
tpm2_seal_trusted(). This allows to add robustness to the command
construction without requiring to calculate buffer sizes manually.

Signed-off-by: default avatarJames Bottomley <James.Bottomley@HansenPartnership.com>
Reviewed-by: default avatarStefan Berger <stefanb@linux.ibm.com>
Reviewed-by: default avatarJarkko Sakkinen <jarkko@kernel.org>
Tested-by: default avatarJarkko Sakkinen <jarkko@kernel.org>
Signed-off-by: default avatarJarkko Sakkinen <jarkko@kernel.org>
parent acd5eb4f

security/keys/trusted-keys/trusted_tpm2.c

+31 −23
Original line number Diff line number Diff line
@@ -228,8 +228,9 @@ int tpm2_seal_trusted(struct tpm_chip *chip, 
		      struct trusted_key_payload *payload,

		      struct trusted_key_options *options)

{

	off_t offset = TPM_HEADER_SIZE;

	struct tpm_buf buf, sized;

	int blob_len = 0;

	struct tpm_buf buf;

	u32 hash;

	u32 flags;

	int i;
@@ -258,6 +259,14 @@ int tpm2_seal_trusted(struct tpm_chip *chip, 
		return rc;

	}



	rc = tpm_buf_init_sized(&sized);

	if (rc) {

		tpm_buf_destroy(&buf);

		tpm_put_ops(chip);

		return rc;

	}



	tpm_buf_reset(&buf, TPM2_ST_SESSIONS, TPM2_CC_CREATE);

	tpm_buf_append_u32(&buf, options->keyhandle);

	tpm2_buf_append_auth(&buf, TPM2_RS_PW,

			     NULL /* nonce */, 0,
@@ -266,36 +275,36 @@ int tpm2_seal_trusted(struct tpm_chip *chip, 
			     TPM_DIGEST_SIZE);



	/* sensitive */

	tpm_buf_append_u16(&buf, 4 + options->blobauth_len + payload->key_len);

	tpm_buf_append_u16(&sized, options->blobauth_len);



	tpm_buf_append_u16(&buf, options->blobauth_len);

	if (options->blobauth_len)

		tpm_buf_append(&buf, options->blobauth, options->blobauth_len);

		tpm_buf_append(&sized, options->blobauth, options->blobauth_len);



	tpm_buf_append_u16(&buf, payload->key_len);

	tpm_buf_append(&buf, payload->key, payload->key_len);

	tpm_buf_append_u16(&sized, payload->key_len);

	tpm_buf_append(&sized, payload->key, payload->key_len);

	tpm_buf_append(&buf, sized.data, sized.length);



	/* public */

	tpm_buf_append_u16(&buf, 14 + options->policydigest_len);

	tpm_buf_append_u16(&buf, TPM_ALG_KEYEDHASH);

	tpm_buf_append_u16(&buf, hash);

	tpm_buf_reset_sized(&sized);

	tpm_buf_append_u16(&sized, TPM_ALG_KEYEDHASH);

	tpm_buf_append_u16(&sized, hash);



	/* key properties */

	flags = 0;

	flags |= options->policydigest_len ? 0 : TPM2_OA_USER_WITH_AUTH;

	flags |= payload->migratable ? 0 : (TPM2_OA_FIXED_TPM |

					    TPM2_OA_FIXED_PARENT);

	tpm_buf_append_u32(&buf, flags);

	flags |= payload->migratable ? 0 : (TPM2_OA_FIXED_TPM | TPM2_OA_FIXED_PARENT);

	tpm_buf_append_u32(&sized, flags);



	/* policy */

	tpm_buf_append_u16(&buf, options->policydigest_len);

	tpm_buf_append_u16(&sized, options->policydigest_len);

	if (options->policydigest_len)

		tpm_buf_append(&buf, options->policydigest,

			       options->policydigest_len);

		tpm_buf_append(&sized, options->policydigest, options->policydigest_len);



	/* public parameters */

	tpm_buf_append_u16(&buf, TPM_ALG_NULL);

	tpm_buf_append_u16(&buf, 0);

	tpm_buf_append_u16(&sized, TPM_ALG_NULL);

	tpm_buf_append_u16(&sized, 0);



	tpm_buf_append(&buf, sized.data, sized.length);



	/* outside info */

	tpm_buf_append_u16(&buf, 0);
@@ -312,21 +321,20 @@ int tpm2_seal_trusted(struct tpm_chip *chip, 
	if (rc)

		goto out;



	blob_len = be32_to_cpup((__be32 *) &buf.data[TPM_HEADER_SIZE]);

	if (blob_len > MAX_BLOB_SIZE) {

	blob_len = tpm_buf_read_u32(&buf, &offset);

	if (blob_len > MAX_BLOB_SIZE || buf.flags & TPM_BUF_BOUNDARY_ERROR) {

		rc = -E2BIG;

		goto out;

	}

	if (tpm_buf_length(&buf) < TPM_HEADER_SIZE + 4 + blob_len) {

	if (buf.length - offset < blob_len) {

		rc = -EFAULT;

		goto out;

	}



	blob_len = tpm2_key_encode(payload, options,

				   &buf.data[TPM_HEADER_SIZE + 4],

				   blob_len);

	blob_len = tpm2_key_encode(payload, options, &buf.data[offset], blob_len);



out:

	tpm_buf_destroy(&sized);

	tpm_buf_destroy(&buf);



	if (rc > 0) {