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 #if defined(CONFIG_SHA384) || defined(CONFIG_SHA512)
  16 #define HASH_MAX_DIGEST_SIZE    64
  17 #else
  18 #define HASH_MAX_DIGEST_SIZE    32
  19 #endif
  20
  21 enum {
  22         HASH_FLAG_VERIFY        = 1 << 0,       /* Enable verify mode */
  23         HASH_FLAG_ENV           = 1 << 1,       /* Allow env vars */
  24 };
  25
  26 struct hash_algo {
  27         const char *name;                       /* Name of algorithm */
  28         int digest_size;                        /* Length of digest */
  29         /**
  30          * hash_func_ws: Generic hashing function
  31          *
  32          * This is the generic prototype for a hashing function. We only
  33          * have the watchdog version at present.
  34          *
  35          * @input:      Input buffer
  36          * @ilen:       Input buffer length
  37          * @output:     Checksum result (length depends on algorithm)
  38          * @chunk_sz:   Trigger watchdog after processing this many bytes
  39          */
  40         void (*hash_func_ws)(const unsigned char *input, unsigned int ilen,
  41                 unsigned char *output, unsigned int chunk_sz);
  42         int chunk_size;                         /* Watchdog chunk size */
  43         /*
  44          * hash_init: Create the context for progressive hashing
  45          *
  46          * @algo: Pointer to the hash_algo struct
  47          * @ctxp: Pointer to the pointer of the context for hashing
  48          * @return 0 if ok, -1 on error
  49          */
  50         int (*hash_init)(struct hash_algo *algo, void **ctxp);
  51         /*
  52          * hash_update: Perform hashing on the given buffer
  53          *
  54          * The context is freed by this function if an error occurs.
  55          *
  56          * @algo: Pointer to the hash_algo struct
  57          * @ctx: Pointer to the context for hashing
  58          * @buf: Pointer to the buffer being hashed
  59          * @size: Size of the buffer being hashed
  60          * @is_last: 1 if this is the last update; 0 otherwise
  61          * @return 0 if ok, -1 on error
  62          */
  63         int (*hash_update)(struct hash_algo *algo, void *ctx, const void *buf,
  64                            unsigned int size, int is_last);
  65         /*
  66          * hash_finish: Write the hash result to the given buffer
  67          *
  68          * The context is freed by this function.
  69          *
  70          * @algo: Pointer to the hash_algo struct
  71          * @ctx: Pointer to the context for hashing
  72          * @dest_buf: Pointer to the buffer for the result
  73          * @size: Size of the buffer for the result
  74          * @return 0 if ok, -ENOSPC if size of the result buffer is too small
  75          *   or -1 on other errors
  76          */
  77         int (*hash_finish)(struct hash_algo *algo, void *ctx, void *dest_buf,
  78                            int size);
  79 };
  80
  81 #ifndef USE_HOSTCC
  82 /**
  83  * hash_command: Process a hash command for a particular algorithm
  84  *
  85  * This common function is used to implement specific hash commands.
  86  *
  87  * @algo_name:          Hash algorithm being used (lower case!)
  88  * @flags:              Flags value (HASH_FLAG_...)
  89  * @cmdtp:              Pointer to command table entry
  90  * @flag:               Some flags normally 0 (see CMD_FLAG_.. above)
  91  * @argc:               Number of arguments (arg 0 must be the command text)
  92  * @argv:               Arguments
  93  */
  94 int hash_command(const char *algo_name, int flags, struct cmd_tbl *cmdtp,
  95                  int flag, int argc, char *const argv[]);
  96
  97 /**
  98  * hash_block() - Hash a block according to the requested algorithm
  99  *
 100  * The caller probably knows the hash length for the chosen algorithm, but
 101  * in order to provide a general interface, and output_size parameter is
 102  * provided.
 103  *
 104  * @algo_name:          Hash algorithm to use
 105  * @data:               Data to hash
 106  * @len:                Lengh of data to hash in bytes
 107  * @output:             Place to put hash value
 108  * @output_size:        On entry, pointer to the number of bytes available in
 109  *                      output. On exit, pointer to the number of bytes used.
 110  *                      If NULL, then it is assumed that the caller has
 111  *                      allocated enough space for the hash. This is possible
 112  *                      since the caller is selecting the algorithm.
 113  * @return 0 if ok, -ve on error: -EPROTONOSUPPORT for an unknown algorithm,
 114  * -ENOSPC if the output buffer is not large enough.
 115  */
 116 int hash_block(const char *algo_name, const void *data, unsigned int len,
 117                uint8_t *output, int *output_size);
 118
 119 #endif /* !USE_HOSTCC */
 120
 121 /**
 122  * hash_lookup_algo() - Look up the hash_algo struct for an algorithm
 123  *
 124  * The function returns the pointer to the struct or -EPROTONOSUPPORT if the
 125  * algorithm is not available.
 126  *
 127  * @algo_name: Hash algorithm to look up
 128  * @algop: Pointer to the hash_algo struct if found
 129  *
 130  * @return 0 if ok, -EPROTONOSUPPORT for an unknown algorithm.
 131  */
 132 int hash_lookup_algo(const char *algo_name, struct hash_algo **algop);
 133
 134 /**
 135  * hash_progressive_lookup_algo() - Look up hash_algo for prog. hash support
 136  *
 137  * The function returns the pointer to the struct or -EPROTONOSUPPORT if the
 138  * algorithm is not available with progressive hash support.
 139  *
 140  * @algo_name: Hash algorithm to look up
 141  * @algop: Pointer to the hash_algo struct if found
 142  *
 143  * @return 0 if ok, -EPROTONOSUPPORT for an unknown algorithm.
 144  */
 145 int hash_progressive_lookup_algo(const char *algo_name,
 146                                  struct hash_algo **algop);
 147
 148 /**
 149  * hash_parse_string() - Parse hash string into a binary array
 150  *
 151  * The function parses a hash string into a binary array that
 152  * can for example easily be used to compare to hash values.
 153  *
 154  * @algo_name: Hash algorithm to look up
 155  * @str: Hash string to get parsed
 156  * @result: Binary array of the parsed hash string
 157  *
 158  * @return 0 if ok, -EPROTONOSUPPORT for an unknown algorithm.
 159  */
 160 int hash_parse_string(const char *algo_name, const char *str, uint8_t *result);
 161
 162 #endif