/*
 * Copyright (C) 2018 Tobias Brunner
 * Copyright (C) 2016-2020 Andreas Steffen
 * HSR Hochschule fuer Technik Rapperswil
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by the
 * Free Software Foundation; either version 2 of the License, or (at your
 * option) any later version.  See <http://www.fsf.org/copyleft/gpl.txt>.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
 * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * for more details.
 */

/**
 * @defgroup libtpmtss libtpmtss
 *
 * @addtogroup libtpmtss
 * @{
 */

#ifndef TPM_TSS_H_
#define TPM_TSS_H_

#include "tpm_tss_quote_info.h"

#include <library.h>
#include <crypto/hashers/hasher.h>

typedef enum tpm_version_t tpm_version_t;
typedef struct tpm_tss_t tpm_tss_t;

/**
 * TPM Versions
 */
enum tpm_version_t {
	TPM_VERSION_ANY,
	TPM_VERSION_1_2,
	TPM_VERSION_2_0,
};

/**
 * TPM access via TSS public interface
 */
struct tpm_tss_t {

	/**
	 * Get TPM version supported by TSS
	 *
	 * @return				TPM version
	 */
	tpm_version_t (*get_version)(tpm_tss_t *this);

	/**
	 * Get TPM version info (TPM 1.2 only)
	 *
	 * @return				TPM version info struct
	 */
	chunk_t (*get_version_info)(tpm_tss_t *this);

	/**
	 * Generate AIK key pair bound to TPM (TPM 1.2 only)
	 *
	 * @param ca_modulus	RSA modulus of CA public key
	 * @param aik_blob		AIK private key blob
	 * @param aik_pubkey	AIK public key
	 * @return				TRUE if AIK key generation succeeded
	 */
	bool (*generate_aik)(tpm_tss_t *this, chunk_t ca_modulus,
						 chunk_t *aik_blob, chunk_t *aik_pubkey,
						 chunk_t *identity_req);

	/**
	 * Get public key from TPM using its object handle (TPM 2.0 only)
	 *
	 * @param handle		key object handle
	 * @return				public key in PKCS#1 format
	 */
	chunk_t (*get_public)(tpm_tss_t *this, uint32_t handle);

	/**
	 * Return signature schemes supported by the given key (TPM 2.0 only)
	 *
	 * @param handle		key object handle
	 * @return				enumerator over signature_params_t*
	 */
	enumerator_t *(*supported_signature_schemes)(tpm_tss_t *this,
												 uint32_t handle);

	/**
	 * Check if there is an assigned PCR bank for the given hash algorithm
	 *
	 * @param alg			hash algorithm
	 * @return				TRUE if a PCR bank for this algorithm exists
	 */
	bool (*has_pcr_bank)(tpm_tss_t *this, hash_algorithm_t alg);

	/**
	 * Retrieve the current value of a PCR register in a given PCR bank
	 *
	 * @param pcr_num		PCR number
	 * @param pcr_value		PCR value returned
	 * @param alg			hash algorithm, selects PCR bank (TPM 2.0 only)
	 * @return				TRUE if PCR value retrieval succeeded
	 */
	bool (*read_pcr)(tpm_tss_t *this, uint32_t pcr_num, chunk_t *pcr_value,
					 hash_algorithm_t alg);

	/**
	 * Extend a PCR register in a given PCR bank with a hash value
	 *
	 * @param pcr_num		PCR number
	 * @param pcr_value		extended PCR value returned
	 * @param hash			data to be extended into the PCR
	 * @param alg			hash algorithm, selects PCR bank (TPM 2.0 only)
	 * @return				TRUE if PCR extension succeeded
	 */
	bool (*extend_pcr)(tpm_tss_t *this, uint32_t pcr_num, chunk_t *pcr_value,
					   chunk_t data, hash_algorithm_t alg);

	/**
	 * Do a quote signature over a selection of PCR registers
	 *
	 * @param aik_handle	object handle of AIK to be used for quote signature
	 * @param pcr_sel		selection of PCR registers
	 * @param alg			hash algorithm to be used for quote signature
	 * @param data			additional data to be hashed into the quote
	 * @param quote_mode	define current and legacy TPM quote modes
	 * @param quote_info	returns various info covered by quote signature
	 * @param quote_sig		returns quote signature
	 * @return				TRUE if quote signature succeeded
	 */
	bool (*quote)(tpm_tss_t *this, uint32_t aik_handle, uint32_t pcr_sel,
				  hash_algorithm_t alg, chunk_t data,
				  tpm_quote_mode_t *quote_mode,
				  tpm_tss_quote_info_t **quote_info, chunk_t *quote_sig);

	/**
	 * Do a signature over a data hash using a TPM key handle (TPM 2.0 only)
	 *
	 * @param handle		object handle of TPM key to be used for signature
	 * @param hierarchy		hierarchy the TPM key object is attached to
	 * @param scheme		scheme to be used for signature
	 * @param param			signature scheme parameters
	 * @param data			data to be hashed and signed
	 * @param pin			PIN code or empty chunk
	 * @param signature		returns signature
	 * @return				TRUE if signature succeeded
	 */
	bool (*sign)(tpm_tss_t *this, uint32_t hierarchy, uint32_t handle,
				 signature_scheme_t scheme, void *params, chunk_t data,
				 chunk_t pin, chunk_t *signature);

	/**
	 * Get random bytes from the TPM
	 *
	 * @param bytes			number of random bytes requested
	 * @param buffer		buffer where the random bytes are written into
	 * @return				TRUE if random bytes could be delivered
	 */
	bool (*get_random)(tpm_tss_t *this, size_t bytes, uint8_t *buffer);

	/**
	 * Get a data blob from TPM NV store using its object handle (TPM 2.0 only)
	 *
	 * @param handle		object handle of TPM key to be used for signature
	 * @param hierarchy		hierarchy the TPM key object is attached to
	 * @param pin			PIN code or empty chunk
	 * @param data			returns data blob
	 * @return				TRUE if data retrieval succeeded
	 */
	bool (*get_data)(tpm_tss_t *this, uint32_t hierarchy, uint32_t handle,
					 chunk_t pin, chunk_t *data);

	/**
	 * Get an event digest from a TPM measurement log
	 *
	 * @param fd			file descriptor of the measurement log
	 * @param hash			hash algorithm of the digest to be extracted
	 * @param digest		allocated chunk_t containing event digest
	 * @return				TRUE if event digest was successfully extracted
	 */
	bool (*get_event_digest)(tpm_tss_t *this, int fd, hash_algorithm_t alg,
							 chunk_t *digest);

	/**
	 * Destroy a tpm_tss_t.
	 */
	void (*destroy)(tpm_tss_t *this);
};

/**
 * Create a tpm_tss instance.
 *
 * @param version	TPM version that must be supported by TSS
 */
tpm_tss_t *tpm_tss_probe(tpm_version_t version);

/**
 * libtpmtss initialization function
 *
 * @return					TRUE if initialization was successful
 */
bool libtpmtss_init(void);

/**
 * libtpmtss de-initialization function
 */
void libtpmtss_deinit(void);

#endif /** TPM_TSS_H_ @}*/
