include/hash.h

   1 /*
   2  * Copyright (c) 2012 The Chromium OS Authors.
   3  * SPDX-License-Identifier:     GPL-2.0+
   4  */
   5
   6 #ifndef _HASH_H
   7 #define _HASH_H
   8
   9 #if defined(CONFIG_SHA1SUM_VERIFY) || defined(CONFIG_CRC32_VERIFY)
  10 #define CONFIG_HASH_VERIFY
  11 #endif
  12
  13 struct hash_algo {
  14         const char *name;                       /* Name of algorithm */
  15         int digest_size;                        /* Length of digest */
  16         /**
  17          * hash_func_ws: Generic hashing function
  18          *
  19          * This is the generic prototype for a hashing function. We only
  20          * have the watchdog version at present.
  21          *
  22          * @input:      Input buffer
  23          * @ilen:       Input buffer length
  24          * @output:     Checksum result (length depends on algorithm)
  25          * @chunk_sz:   Trigger watchdog after processing this many bytes
  26          */
  27         void (*hash_func_ws)(const unsigned char *input, unsigned int ilen,
  28                 unsigned char *output, unsigned int chunk_sz);
  29         int chunk_size;                         /* Watchdog chunk size */
  30 };
  31
  32 /*
  33  * Maximum digest size for all algorithms we support. Having this value
  34  * avoids a malloc() or C99 local declaration in common/cmd_hash.c.
  35  */
  36 #define HASH_MAX_DIGEST_SIZE    32
  37
  38 enum {
  39         HASH_FLAG_VERIFY        = 1 << 0,       /* Enable verify mode */
  40         HASH_FLAG_ENV           = 1 << 1,       /* Allow env vars */
  41 };
  42
  43 /**
  44  * hash_command: Process a hash command for a particular algorithm
  45  *
  46  * This common function is used to implement specific hash commands.
  47  *
  48  * @algo_name:          Hash algorithm being used (lower case!)
  49  * @flags:              Flags value (HASH_FLAG_...)
  50  * @cmdtp:              Pointer to command table entry
  51  * @flag:               Some flags normally 0 (see CMD_FLAG_.. above)
  52  * @argc:               Number of arguments (arg 0 must be the command text)
  53  * @argv:               Arguments
  54  */
  55 int hash_command(const char *algo_name, int flags, cmd_tbl_t *cmdtp, int flag,
  56                  int argc, char * const argv[]);
  57
  58 /**
  59  * hash_block() - Hash a block according to the requested algorithm
  60  *
  61  * The caller probably knows the hash length for the chosen algorithm, but
  62  * in order to provide a general interface, and output_size parameter is
  63  * provided.
  64  *
  65  * @algo_name:          Hash algorithm to use
  66  * @data:               Data to hash
  67  * @len:                Lengh of data to hash in bytes
  68  * @output:             Place to put hash value
  69  * @output_size:        On entry, pointer to the number of bytes available in
  70  *                      output. On exit, pointer to the number of bytes used.
  71  *                      If NULL, then it is assumed that the caller has
  72  *                      allocated enough space for the hash. This is possible
  73  *                      since the caller is selecting the algorithm.
  74  * @return 0 if ok, -ve on error: -EPROTONOSUPPORT for an unknown algorithm,
  75  * -ENOSPC if the output buffer is not large enough.
  76  */
  77 int hash_block(const char *algo_name, const void *data, unsigned int len,
  78                uint8_t *output, int *output_size);
  79
  80 #endif