/*
   * Copyright (c) 2012 The Chromium OS Authors.
   *
   * (C) Copyright 2011
   * Joe Hershberger, National Instruments, joe.hershberger@ni.com
   *
   * (C) Copyright 2000
   * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
   *

   * SPDX-License-Identifier:	GPL-2.0+

   */
  
  #include <common.h>
  #include <command.h>

  #include <hw_sha.h>

  #include <hash.h>
  #include <sha1.h>
  #include <sha256.h>

  #include <asm/io.h>

  #include <asm/errno.h>

  
  /*
   * These are the hash algorithms we support. Chips which support accelerated

   * crypto could perhaps add named version of these algorithms here. Note that
   * algorithm names must be in lower case.

   */
  static struct hash_algo hash_algo[] = {

  	/*

  	 * CONFIG_SHA_HW_ACCEL is defined if hardware acceleration is
  	 * available.
  	 */
  #ifdef CONFIG_SHA_HW_ACCEL
  	{
  		"sha1",
  		SHA1_SUM_LEN,
  		hw_sha1,
  		CHUNKSZ_SHA1,
  	}, {
  		"sha256",
  		SHA256_SUM_LEN,
  		hw_sha256,
  		CHUNKSZ_SHA256,
  	},
  #endif
  	/*

  	 * This is CONFIG_CMD_SHA1SUM instead of CONFIG_SHA1 since otherwise
  	 * it bloats the code for boards which use SHA1 but not the 'hash'
  	 * or 'sha1sum' commands.
  	 */
  #ifdef CONFIG_CMD_SHA1SUM

  	{

  		"sha1",

  		SHA1_SUM_LEN,
  		sha1_csum_wd,
  		CHUNKSZ_SHA1,
  	},

  #define MULTI_HASH

  #endif
  #ifdef CONFIG_SHA256
  	{

  		"sha256",

  		SHA256_SUM_LEN,
  		sha256_csum_wd,
  		CHUNKSZ_SHA256,
  	},

  #define MULTI_HASH

  #endif

  	{

  		"crc32",

  		4,
  		crc32_wd_buf,
  		CHUNKSZ_CRC32,
  	},

  };

  #if defined(CONFIG_HASH_VERIFY) || defined(CONFIG_CMD_HASH)
  #define MULTI_HASH
  #endif
  
  /* Try to minimize code size for boards that don't want much hashing */
  #ifdef MULTI_HASH
  #define multi_hash()	1
  #else
  #define multi_hash()	0
  #endif

  /**
   * store_result: Store the resulting sum to an address or variable
   *
   * @algo:		Hash algorithm being used
   * @sum:		Hash digest (algo->digest_size bytes)
   * @dest:		Destination, interpreted as a hex address if it starts

   *			with * (or allow_env_vars is 0) or otherwise as an
   *			environment variable.
   * @allow_env_vars:	non-zero to permit storing the result to an
   *			variable environment

   */
  static void store_result(struct hash_algo *algo, const u8 *sum,

  			 const char *dest, int allow_env_vars)

  {
  	unsigned int i;

  	int env_var = 0;

  	/*
  	 * If environment variables are allowed, then we assume that 'dest'
  	 * is an environment variable, unless it starts with *, in which
  	 * case we assume it is an address. If not allowed, it is always an
  	 * address. This is to support the crc32 command.
  	 */
  	if (allow_env_vars) {
  		if (*dest == '*')
  			dest++;
  		else
  			env_var = 1;
  	}

  	if (env_var) {

  		char str_output[HASH_MAX_DIGEST_SIZE * 2 + 1];
  		char *str_ptr = str_output;
  
  		for (i = 0; i < algo->digest_size; i++) {
  			sprintf(str_ptr, "%02x", sum[i]);
  			str_ptr += 2;
  		}
  		str_ptr = '\0';
  		setenv(dest, str_output);

  	} else {

  		ulong addr;
  		void *buf;

  		addr = simple_strtoul(dest, NULL, 16);
  		buf = map_sysmem(addr, algo->digest_size);
  		memcpy(buf, sum, algo->digest_size);
  		unmap_sysmem(buf);

  	}
  }
  
  /**
   * parse_verify_sum: Parse a hash verification parameter
   *
   * @algo:		Hash algorithm being used
   * @verify_str:		Argument to parse. If it starts with * then it is
   *			interpreted as a hex address containing the hash.
   *			If the length is exactly the right number of hex digits
   *			for the digest size, then we assume it is a hex digest.
   *			Otherwise we assume it is an environment variable, and
   *			look up its value (it must contain a hex digest).
   * @vsum:		Returns binary digest value (algo->digest_size bytes)

   * @allow_env_vars:	non-zero to permit storing the result to an environment
   *			variable. If 0 then verify_str is assumed to be an
   *			address, and the * prefix is not expected.

   * @return 0 if ok, non-zero on error
   */

  static int parse_verify_sum(struct hash_algo *algo, char *verify_str, u8 *vsum,
  			    int allow_env_vars)

  {

  	int env_var = 0;
  
  	/* See comment above in store_result() */
  	if (allow_env_vars) {
  		if (*verify_str == '*')
  			verify_str++;
  		else
  			env_var = 1;
  	}
  
  	if (env_var) {

  		ulong addr;
  		void *buf;

  		addr = simple_strtoul(verify_str, NULL, 16);
  		buf = map_sysmem(addr, algo->digest_size);
  		memcpy(vsum, buf, algo->digest_size);

  	} else {
  		unsigned int i;
  		char *vsum_str;
  		int digits = algo->digest_size * 2;
  
  		/*
  		 * As with the original code from sha1sum.c, we assume that a
  		 * string which matches the digest size exactly is a hex
  		 * string and not an environment variable.
  		 */
  		if (strlen(verify_str) == digits)
  			vsum_str = verify_str;
  		else {
  			vsum_str = getenv(verify_str);
  			if (vsum_str == NULL || strlen(vsum_str) != digits) {
  				printf("Expected %d hex digits in env var
  ",
  				       digits);
  				return 1;
  			}
  		}
  
  		for (i = 0; i < algo->digest_size; i++) {
  			char *nullp = vsum_str + (i + 1) * 2;
  			char end = *nullp;
  
  			*nullp = '\0';
  			vsum[i] = simple_strtoul(vsum_str + (i * 2), NULL, 16);
  			*nullp = end;
  		}
  	}
  	return 0;
  }
  
  static struct hash_algo *find_hash_algo(const char *name)
  {
  	int i;
  
  	for (i = 0; i < ARRAY_SIZE(hash_algo); i++) {

  		if (!strcmp(name, hash_algo[i].name))

  			return &hash_algo[i];
  	}
  
  	return NULL;
  }
  
  static void show_hash(struct hash_algo *algo, ulong addr, ulong len,
  		      u8 *output)
  {
  	int i;
  
  	printf("%s for %08lx ... %08lx ==> ", algo->name, addr, addr + len - 1);
  	for (i = 0; i < algo->digest_size; i++)
  		printf("%02x", output[i]);
  }

  int hash_block(const char *algo_name, const void *data, unsigned int len,
  	       uint8_t *output, int *output_size)
  {
  	struct hash_algo *algo;
  
  	algo = find_hash_algo(algo_name);
  	if (!algo) {
  		debug("Unknown hash algorithm '%s'
  ", algo_name);
  		return -EPROTONOSUPPORT;
  	}
  	if (output_size && *output_size < algo->digest_size) {
  		debug("Output buffer size %d too small (need %d bytes)",
  		      *output_size, algo->digest_size);
  		return -ENOSPC;
  	}
  	if (output_size)
  		*output_size = algo->digest_size;
  	algo->hash_func_ws(data, len, output, algo->chunk_size);
  
  	return 0;
  }

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

  		 int argc, char * const argv[])
  {

  	ulong addr, len;

  
  	if (argc < 2)
  		return CMD_RET_USAGE;

  	addr = simple_strtoul(*argv++, NULL, 16);
  	len = simple_strtoul(*argv++, NULL, 16);

  	if (multi_hash()) {
  		struct hash_algo *algo;
  		u8 output[HASH_MAX_DIGEST_SIZE];
  		u8 vsum[HASH_MAX_DIGEST_SIZE];

  		void *buf;

  		algo = find_hash_algo(algo_name);
  		if (!algo) {
  			printf("Unknown hash algorithm '%s'
  ", algo_name);
  			return CMD_RET_USAGE;
  		}
  		argc -= 2;
  
  		if (algo->digest_size > HASH_MAX_DIGEST_SIZE) {
  			puts("HASH_MAX_DIGEST_SIZE exceeded
  ");
  			return 1;
  		}

  		buf = map_sysmem(addr, len);
  		algo->hash_func_ws(buf, len, output, algo->chunk_size);
  		unmap_sysmem(buf);

  		/* Try to avoid code bloat when verify is not needed */

  #ifdef CONFIG_HASH_VERIFY

  		if (flags & HASH_FLAG_VERIFY) {

  #else

  		if (0) {

  #endif

  			if (!argc)
  				return CMD_RET_USAGE;
  			if (parse_verify_sum(algo, *argv, vsum,

  					flags & HASH_FLAG_ENV)) {

  				printf("ERROR: %s does not contain a valid "
  					"%s sum
  ", *argv, algo->name);
  				return 1;
  			}
  			if (memcmp(output, vsum, algo->digest_size) != 0) {
  				int i;

  				show_hash(algo, addr, len, output);
  				printf(" != ");
  				for (i = 0; i < algo->digest_size; i++)
  					printf("%02x", vsum[i]);
  				puts(" ** ERROR **
  ");
  				return 1;
  			}
  		} else {

  			show_hash(algo, addr, len, output);

  			printf("
  ");
  
  			if (argc) {
  				store_result(algo, output, *argv,
  					flags & HASH_FLAG_ENV);
  			}

  		}

  
  	/* Horrible code size hack for boards that just want crc32 */

  	} else {

  		ulong crc;
  		ulong *ptr;
  
  		crc = crc32_wd(0, (const uchar *)addr, len, CHUNKSZ_CRC32);
  
  		printf("CRC32 for %08lx ... %08lx ==> %08lx
  ",
  				addr, addr + len - 1, crc);

  		if (argc >= 3) {
  			ptr = (ulong *)simple_strtoul(argv[0], NULL, 16);

  			*ptr = crc;

  		}

  	}
  
  	return 0;
  }