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 /*
  10  * Maximum digest size for all algorithms we support. Having this value
  11  * avoids a malloc() or C99 local declaration in common/cmd_hash.c.
  12  */
  13 #define HASH_MAX_DIGEST_SIZE    32
  14
  15 enum {
  16         HASH_FLAG_VERIFY        = 1 << 0,       /* Enable verify mode */
  17         HASH_FLAG_ENV           = 1 << 1,       /* Allow env vars */
  18 };
  19
  20 #if defined(CONFIG_SHA1SUM_VERIFY) || defined(CONFIG_CRC32_VERIFY)
  21 #define CONFIG_HASH_VERIFY
  22 #endif
  23
  24 struct hash_algo {
  25         const char *name;                       /* Name of algorithm */
  26         int digest_size;                        /* Length of digest */
  27         /**
  28          * hash_func_ws: Generic hashing function
  29          *
  30          * This is the generic prototype for a hashing function. We only
  31          * have the watchdog version at present.
  32          *
  33          * @input:      Input buffer
  34          * @ilen:       Input buffer length
  35          * @output:     Checksum result (length depends on algorithm)
  36          * @chunk_sz:   Trigger watchdog after processing this many bytes
  37          */
  38         void (*hash_func_ws)(const unsigned char *input, unsigned int ilen,
  39                 unsigned char *output, unsigned int chunk_sz);
  40         int chunk_size;                         /* Watchdog chunk size */
  41         /*
  42          * hash_init: Create the context for progressive hashing
  43          *
  44          * @algo: Pointer to the hash_algo struct
  45          * @ctxp: Pointer to the pointer of the context for hashing
  46          * @return 0 if ok, -1 on error
  47          */
  48         int (*hash_init)(struct hash_algo *algo, void **ctxp);
  49         /*
  50          * hash_update: Perform hashing on the given buffer
  51          *
  52          * The context is freed by this function if an error occurs.
  53          *
  54          * @algo: Pointer to the hash_algo struct
  55          * @ctx: Pointer to the context for hashing
  56          * @buf: Pointer to the buffer being hashed
  57          * @size: Size of the buffer being hashed
  58          * @is_last: 1 if this is the last update; 0 otherwise
  59          * @return 0 if ok, -1 on error
  60          */
  61         int (*hash_update)(struct hash_algo *algo, void *ctx, const void *buf,
  62                            unsigned int size, int is_last);
  63         /*
  64          * hash_finish: Write the hash result to the given buffer
  65          *
  66          * The context is freed by this function.
  67          *
  68          * @algo: Pointer to the hash_algo struct
  69          * @ctx: Pointer to the context for hashing
  70          * @dest_buf: Pointer to the buffer for the result
  71          * @size: Size of the buffer for the result
  72          * @return 0 if ok, -ENOSPC if size of the result buffer is too small
  73          *   or -1 on other errors
  74          */
  75         int (*hash_finish)(struct hash_algo *algo, void *ctx, void *dest_buf,
  76                            int size);
  77 };
  78
  79 #ifndef USE_HOSTCC
  80 /**
  81  * hash_command: Process a hash command for a particular algorithm
  82  *
  83  * This common function is used to implement specific hash commands.
  84  *
  85  * @algo_name:          Hash algorithm being used (lower case!)
  86  * @flags:              Flags value (HASH_FLAG_...)
  87  * @cmdtp:              Pointer to command table entry
  88  * @flag:               Some flags normally 0 (see CMD_FLAG_.. above)
  89  * @argc:               Number of arguments (arg 0 must be the command text)
  90  * @argv:               Arguments
  91  */
  92 int hash_command(const char *algo_name, int flags, cmd_tbl_t *cmdtp, int flag,
  93                  int argc, char * const argv[]);
  94
  95 /**
  96  * hash_block() - Hash a block according to the requested algorithm
  97  *
  98  * The caller probably knows the hash length for the chosen algorithm, but
  99  * in order to provide a general interface, and output_size parameter is
 100  * provided.
 101  *
 102  * @algo_name:          Hash algorithm to use
 103  * @data:               Data to hash
 104  * @len:                Lengh of data to hash in bytes
 105  * @output:             Place to put hash value
 106  * @output_size:        On entry, pointer to the number of bytes available in
 107  *                      output. On exit, pointer to the number of bytes used.
 108  *                      If NULL, then it is assumed that the caller has
 109  *                      allocated enough space for the hash. This is possible
 110  *                      since the caller is selecting the algorithm.
 111  * @return 0 if ok, -ve on error: -EPROTONOSUPPORT for an unknown algorithm,
 112  * -ENOSPC if the output buffer is not large enough.
 113  */
 114 int hash_block(const char *algo_name, const void *data, unsigned int len,
 115                uint8_t *output, int *output_size);
 116
 117 #endif /* !USE_HOSTCC */
 118
 119 /**
 120  * hash_lookup_algo() - Look up the hash_algo struct for an algorithm
 121  *
 122  * The function returns the pointer to the struct or -EPROTONOSUPPORT if the
 123  * algorithm is not available.
 124  *
 125  * @algo_name: Hash algorithm to look up
 126  * @algop: Pointer to the hash_algo struct if found
 127  *
 128  * @return 0 if ok, -EPROTONOSUPPORT for an unknown algorithm.
 129  */
 130 int hash_lookup_algo(const char *algo_name, struct hash_algo **algop);
 131
 132 /**
 133  * hash_progressive_lookup_algo() - Look up hash_algo for prog. hash support
 134  *
 135  * The function returns the pointer to the struct or -EPROTONOSUPPORT if the
 136  * algorithm is not available with progressive hash support.
 137  *
 138  * @algo_name: Hash algorithm to look up
 139  * @algop: Pointer to the hash_algo struct if found
 140  *
 141  * @return 0 if ok, -EPROTONOSUPPORT for an unknown algorithm.
 142  */
 143 int hash_progressive_lookup_algo(const char *algo_name,
 144                                  struct hash_algo **algop);
 145
 146 /**
 147  * hash_parse_string() - Parse hash string into a binary array
 148  *
 149  * The function parses a hash string into a binary array that
 150  * can for example easily be used to compare to hash values.
 151  *
 152  * @algo_name: Hash algorithm to look up
 153  * @str: Hash string to get parsed
 154  * @result: Binary array of the parsed hash string
 155  *
 156  * @return 0 if ok, -EPROTONOSUPPORT for an unknown algorithm.
 157  */
 158 int hash_parse_string(const char *algo_name, const char *str, uint8_t *result);
 159
 160 #endif