lib/tpm-v2.c

// SPDX-License-Identifier: GPL-2.0+
/*
 * Copyright (c) 2018 Bootlin
 * Author: Miquel Raynal <miquel.raynal@bootlin.com>
 */

#include <common.h>
#include <dm.h>
#include <tpm-common.h>
#include <tpm-v2.h>
#include "tpm-utils.h"

u32 tpm2_startup(enum tpm2_startup_types mode)
{
	const u8 command_v2[12] = {
		tpm_u16(TPM2_ST_NO_SESSIONS),
		tpm_u32(12),
		tpm_u32(TPM2_CC_STARTUP),
		tpm_u16(mode),
	};
	int ret;

	/*
	 * Note TPM2_Startup command will return RC_SUCCESS the first time,
	 * but will return RC_INITIALIZE otherwise.
	 */
	ret = tpm_sendrecv_command(command_v2, NULL, NULL);
	if (ret && ret != TPM2_RC_INITIALIZE)
		return ret;

	return 0;
}

u32 tpm2_self_test(enum tpm2_yes_no full_test)
{
	const u8 command_v2[12] = {
		tpm_u16(TPM2_ST_NO_SESSIONS),
		tpm_u32(11),
		tpm_u32(TPM2_CC_SELF_TEST),
		full_test,
	};

	return tpm_sendrecv_command(command_v2, NULL, NULL);
}

u32 tpm2_clear(u32 handle, const char *pw, const ssize_t pw_sz)
{
	u8 command_v2[COMMAND_BUFFER_SIZE] = {
		tpm_u16(TPM2_ST_SESSIONS),	/* TAG */
		tpm_u32(27 + pw_sz),		/* Length */
		tpm_u32(TPM2_CC_CLEAR),		/* Command code */

		/* HANDLE */
		tpm_u32(handle),		/* TPM resource handle */

		/* AUTH_SESSION */
		tpm_u32(9 + pw_sz),		/* Authorization size */
		tpm_u32(TPM2_RS_PW),		/* Session handle */
		tpm_u16(0),			/* Size of <nonce> */
						/* <nonce> (if any) */
		0,				/* Attributes: Cont/Excl/Rst */
		tpm_u16(pw_sz),			/* Size of <hmac/password> */
		/* STRING(pw)			   <hmac/password> (if any) */
	};
	unsigned int offset = 27;
	int ret;

	/*
	 * Fill the command structure starting from the first buffer:
	 *     - the password (if any)
	 */
	ret = pack_byte_string(command_v2, sizeof(command_v2), "s",
			       offset, pw, pw_sz);
	offset += pw_sz;
	if (ret)
		return TPM_LIB_ERROR;

	return tpm_sendrecv_command(command_v2, NULL, NULL);
}

u32 tpm2_pcr_extend(u32 index, const uint8_t *digest)
{
	u8 command_v2[COMMAND_BUFFER_SIZE] = {
		tpm_u16(TPM2_ST_SESSIONS),	/* TAG */
		tpm_u32(33 + TPM2_DIGEST_LEN),	/* Length */
		tpm_u32(TPM2_CC_PCR_EXTEND),	/* Command code */

		/* HANDLE */
		tpm_u32(index),			/* Handle (PCR Index) */

		/* AUTH_SESSION */
		tpm_u32(9),			/* Authorization size */
		tpm_u32(TPM2_RS_PW),		/* Session handle */
		tpm_u16(0),			/* Size of <nonce> */
						/* <nonce> (if any) */
		0,				/* Attributes: Cont/Excl/Rst */
		tpm_u16(0),			/* Size of <hmac/password> */
						/* <hmac/password> (if any) */
		tpm_u32(1),			/* Count (number of hashes) */
		tpm_u16(TPM2_ALG_SHA256),	/* Algorithm of the hash */
		/* STRING(digest)		   Digest */
	};
	unsigned int offset = 33;
	int ret;

	/*
	 * Fill the command structure starting from the first buffer:
	 *     - the digest
	 */
	ret = pack_byte_string(command_v2, sizeof(command_v2), "s",
			       offset, digest, TPM2_DIGEST_LEN);
	offset += TPM2_DIGEST_LEN;
	if (ret)
		return TPM_LIB_ERROR;

	return tpm_sendrecv_command(command_v2,	NULL, NULL);
}