include/hash.h

   1 /* SPDX-License-Identifier: GPL-2.0+ */
   2 /*
   3  * Copyright (c) 2012 The Chromium OS Authors.
   4  */
   5
   6 #ifndef _HASH_H
   7 #define _HASH_H
   8
   9 struct cmd_tbl;
  10
  11 /*
  12  * Maximum digest size for all algorithms we support. Having this value
  13  * avoids a malloc() or C99 local declaration in common/cmd_hash.c.
  14  */
  15 #define HASH_MAX_DIGEST_SIZE    32
  16
  17 enum {
  18         HASH_FLAG_VERIFY        = 1 << 0,       /* Enable verify mode */
  19         HASH_FLAG_ENV           = 1 << 1,       /* Allow env vars */
  20 };
  21
  22 struct hash_algo {
  23         const char *name;                       /* Name of algorithm */
  24         int digest_size;                        /* Length of digest */
  25         /**
  26          * hash_func_ws: Generic hashing function
  27          *
  28          * This is the generic prototype for a hashing function. We only
  29          * have the watchdog version at present.
  30          *
  31          * @input:      Input buffer
  32          * @ilen:       Input buffer length
  33          * @output:     Checksum result (length depends on algorithm)
  34          * @chunk_sz:   Trigger watchdog after processing this many bytes
  35          */
  36         void (*hash_func_ws)(const unsigned char *input, unsigned int ilen,
  37                 unsigned char *output, unsigned int chunk_sz);
  38         int chunk_size;                         /* Watchdog chunk size */
  39         /*
  40          * hash_init: Create the context for progressive hashing
  41          *
  42          * @algo: Pointer to the hash_algo struct
  43          * @ctxp: Pointer to the pointer of the context for hashing
  44          * @return 0 if ok, -1 on error
  45          */
  46         int (*hash_init)(struct hash_algo *algo, void **ctxp);
  47         /*
  48          * hash_update: Perform hashing on the given buffer
  49          *
  50          * The context is freed by this function if an error occurs.
  51          *
  52          * @algo: Pointer to the hash_algo struct
  53          * @ctx: Pointer to the context for hashing
  54          * @buf: Pointer to the buffer being hashed
  55          * @size: Size of the buffer being hashed
  56          * @is_last: 1 if this is the last update; 0 otherwise
  57          * @return 0 if ok, -1 on error
  58          */
  59         int (*hash_update)(struct hash_algo *algo, void *ctx, const void *buf,
  60                            unsigned int size, int is_last);
  61         /*
  62          * hash_finish: Write the hash result to the given buffer
  63          *
  64          * The context is freed by this function.
  65          *
  66          * @algo: Pointer to the hash_algo struct
  67          * @ctx: Pointer to the context for hashing
  68          * @dest_buf: Pointer to the buffer for the result
  69          * @size: Size of the buffer for the result
  70          * @return 0 if ok, -ENOSPC if size of the result buffer is too small
  71          *   or -1 on other errors
  72          */
  73         int (*hash_finish)(struct hash_algo *algo, void *ctx, void *dest_buf,
  74                            int size);
  75 };
  76
  77 #ifndef USE_HOSTCC
  78 /**
  79  * hash_command: Process a hash command for a particular algorithm
  80  *
  81  * This common function is used to implement specific hash commands.
  82  *
  83  * @algo_name:          Hash algorithm being used (lower case!)
  84  * @flags:              Flags value (HASH_FLAG_...)
  85  * @cmdtp:              Pointer to command table entry
  86  * @flag:               Some flags normally 0 (see CMD_FLAG_.. above)
  87  * @argc:               Number of arguments (arg 0 must be the command text)
  88  * @argv:               Arguments
  89  */
  90 int hash_command(const char *algo_name, int flags, struct cmd_tbl *cmdtp,
  91                  int flag, int argc, char *const argv[]);
  92
  93 /**
  94  * hash_block() - Hash a block according to the requested algorithm
  95  *
  96  * The caller probably knows the hash length for the chosen algorithm, but
  97  * in order to provide a general interface, and output_size parameter is
  98  * provided.
  99  *
 100  * @algo_name:          Hash algorithm to use
 101  * @data:               Data to hash
 102  * @len:                Lengh of data to hash in bytes
 103  * @output:             Place to put hash value
 104  * @output_size:        On entry, pointer to the number of bytes available in
 105  *                      output. On exit, pointer to the number of bytes used.
 106  *                      If NULL, then it is assumed that the caller has
 107  *                      allocated enough space for the hash. This is possible
 108  *                      since the caller is selecting the algorithm.
 109  * @return 0 if ok, -ve on error: -EPROTONOSUPPORT for an unknown algorithm,
 110  * -ENOSPC if the output buffer is not large enough.
 111  */
 112 int hash_block(const char *algo_name, const void *data, unsigned int len,
 113                uint8_t *output, int *output_size);
 114
 115 #endif /* !USE_HOSTCC */
 116
 117 /**
 118  * hash_lookup_algo() - Look up the hash_algo struct for an algorithm
 119  *
 120  * The function returns the pointer to the struct or -EPROTONOSUPPORT if the
 121  * algorithm is not available.
 122  *
 123  * @algo_name: Hash algorithm to look up
 124  * @algop: Pointer to the hash_algo struct if found
 125  *
 126  * @return 0 if ok, -EPROTONOSUPPORT for an unknown algorithm.
 127  */
 128 int hash_lookup_algo(const char *algo_name, struct hash_algo **algop);
 129
 130 /**
 131  * hash_progressive_lookup_algo() - Look up hash_algo for prog. hash support
 132  *
 133  * The function returns the pointer to the struct or -EPROTONOSUPPORT if the
 134  * algorithm is not available with progressive hash support.
 135  *
 136  * @algo_name: Hash algorithm to look up
 137  * @algop: Pointer to the hash_algo struct if found
 138  *
 139  * @return 0 if ok, -EPROTONOSUPPORT for an unknown algorithm.
 140  */
 141 int hash_progressive_lookup_algo(const char *algo_name,
 142                                  struct hash_algo **algop);
 143
 144 /**
 145  * hash_parse_string() - Parse hash string into a binary array
 146  *
 147  * The function parses a hash string into a binary array that
 148  * can for example easily be used to compare to hash values.
 149  *
 150  * @algo_name: Hash algorithm to look up
 151  * @str: Hash string to get parsed
 152  * @result: Binary array of the parsed hash string
 153  *
 154  * @return 0 if ok, -EPROTONOSUPPORT for an unknown algorithm.
 155  */
 156 int hash_parse_string(const char *algo_name, const char *str, uint8_t *result);
 157
 158 #endif