tpm.c

		     - TPM_RESPONSE_AUTH_LENGTH) > *pubkey_len)
			return TPM_LIB_ERROR;
		*pubkey_len = response_length - TPM_RESPONSE_HEADER_LENGTH
			- TPM_RESPONSE_AUTH_LENGTH;
		memcpy(pubkey, response + res_pubkey_offset,
		       response_length - TPM_RESPONSE_HEADER_LENGTH
		       - TPM_RESPONSE_AUTH_LENGTH);
	}

	return 0;
}

#ifdef CONFIG_TPM_LOAD_KEY_BY_SHA1
u32 tpm_find_key_sha1(const u8 auth[20], const u8 pubkey_digest[20],
		      u32 *handle)
{
	u16 key_count;
	u32 key_handles[10];
	u8 buf[288];
	u8 *ptr;
	u32 err;
	u8 digest[20];
	size_t buf_len;
	unsigned int i;

	/* fetch list of already loaded keys in the TPM */
	err = tpm_get_capability(TPM_CAP_HANDLE, TPM_RT_KEY, buf, sizeof(buf));
	if (err)
		return -1;
	key_count = get_unaligned_be16(buf);
	ptr = buf + 2;
	for (i = 0; i < key_count; ++i, ptr += 4)
		key_handles[i] = get_unaligned_be32(ptr);

	/* now search a(/ the) key which we can access with the given auth */
	for (i = 0; i < key_count; ++i) {
		buf_len = sizeof(buf);
		err = tpm_get_pub_key_oiap(key_handles[i], auth, buf, &buf_len);
		if (err && err != TPM_AUTHFAIL)
			return -1;
		if (err)
			continue;
		sha1_csum(buf, buf_len, digest);
		if (!memcmp(digest, pubkey_digest, 20)) {
			*handle = key_handles[i];
			return 0;
		}
	}
	return 1;
}
#endif /* CONFIG_TPM_LOAD_KEY_BY_SHA1 */

#endif /* CONFIG_TPM_AUTH_SESSIONS */

u32 tpm_get_random(void *data, u32 count)
{
	const u8 command[14] = {
		0x0, 0xc1,		/* TPM_TAG */
		0x0, 0x0, 0x0, 0xe,	/* parameter size */
		0x0, 0x0, 0x0, 0x46,	/* TPM_COMMAND_CODE */
	};
	const size_t length_offset = 10;
	const size_t data_size_offset = 10;
	const size_t data_offset = 14;
	u8 buf[COMMAND_BUFFER_SIZE], response[COMMAND_BUFFER_SIZE];
	size_t response_length = sizeof(response);
	u32 data_size;
	u8 *out = data;

	while (count > 0) {
		u32 this_bytes = min((size_t)count,
				     sizeof(response) - data_offset);
		u32 err;

		if (pack_byte_string(buf, sizeof(buf), "sd",
				     0, command, sizeof(command),
				     length_offset, this_bytes))
			return TPM_LIB_ERROR;
		err = tpm_sendrecv_command(buf, response, &response_length);
		if (err)
			return err;
		if (unpack_byte_string(response, response_length, "d",
				       data_size_offset, &data_size))
			return TPM_LIB_ERROR;
		if (data_size > count)
			return TPM_LIB_ERROR;
		if (unpack_byte_string(response, response_length, "s",
				       data_offset, out, data_size))
			return TPM_LIB_ERROR;

		count -= data_size;
		out += data_size;
	}

	return 0;
}