/*
   * Copyright (c) 2012 The Chromium OS Authors.

   * SPDX-License-Identifier:	GPL-2.0+

   */
  
  #ifndef _HASH_H
  #define _HASH_H

  #if defined(CONFIG_SHA1SUM_VERIFY) || defined(CONFIG_CRC32_VERIFY)

  #define CONFIG_HASH_VERIFY
  #endif
  
  struct hash_algo {
  	const char *name;			/* Name of algorithm */
  	int digest_size;			/* Length of digest */
  	/**
  	 * hash_func_ws: Generic hashing function
  	 *
  	 * This is the generic prototype for a hashing function. We only
  	 * have the watchdog version at present.
  	 *
  	 * @input:	Input buffer
  	 * @ilen:	Input buffer length
  	 * @output:	Checksum result (length depends on algorithm)
  	 * @chunk_sz:	Trigger watchdog after processing this many bytes
  	 */
  	void (*hash_func_ws)(const unsigned char *input, unsigned int ilen,
  		unsigned char *output, unsigned int chunk_sz);
  	int chunk_size;				/* Watchdog chunk size */
  };
  
  /*
   * Maximum digest size for all algorithms we support. Having this value
   * avoids a malloc() or C99 local declaration in common/cmd_hash.c.
   */
  #define HASH_MAX_DIGEST_SIZE	32

  enum {
  	HASH_FLAG_VERIFY	= 1 << 0,	/* Enable verify mode */
  	HASH_FLAG_ENV		= 1 << 1,	/* Allow env vars */
  };

  /**
   * hash_command: Process a hash command for a particular algorithm
   *
   * This common function is used to implement specific hash commands.
   *

   * @algo_name:		Hash algorithm being used (lower case!)

   * @flags:		Flags value (HASH_FLAG_...)

   * @cmdtp:		Pointer to command table entry
   * @flag:		Some flags normally 0 (see CMD_FLAG_.. above)
   * @argc:		Number of arguments (arg 0 must be the command text)
   * @argv:		Arguments
   */

  int hash_command(const char *algo_name, int flags, cmd_tbl_t *cmdtp, int flag,

  		 int argc, char * const argv[]);

  /**
   * hash_block() - Hash a block according to the requested algorithm
   *
   * The caller probably knows the hash length for the chosen algorithm, but
   * in order to provide a general interface, and output_size parameter is
   * provided.
   *
   * @algo_name:		Hash algorithm to use
   * @data:		Data to hash
   * @len:		Lengh of data to hash in bytes
   * @output:		Place to put hash value
   * @output_size:	On entry, pointer to the number of bytes available in
   *			output. On exit, pointer to the number of bytes used.
   *			If NULL, then it is assumed that the caller has
   *			allocated enough space for the hash. This is possible
   *			since the caller is selecting the algorithm.
   * @return 0 if ok, -ve on error: -EPROTONOSUPPORT for an unknown algorithm,
   * -ENOSPC if the output buffer is not large enough.
   */
  int hash_block(const char *algo_name, const void *data, unsigned int len,
  	       uint8_t *output, int *output_size);

  #endif