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 * hash_init: Create the context for progressive hashing 32 * 33 * @algo: Pointer to the hash_algo struct 34 * @ctxp: Pointer to the pointer of the context for hashing 35 * @return 0 if ok, -1 on error 36 */ 37 int (*hash_init)(struct hash_algo *algo, void **ctxp); 38 /* 39 * hash_update: Perform hashing on the given buffer 40 * 41 * The context is freed by this function if an error occurs. 42 * 43 * @algo: Pointer to the hash_algo struct 44 * @ctx: Pointer to the context for hashing 45 * @buf: Pointer to the buffer being hashed 46 * @size: Size of the buffer being hashed 47 * @is_last: 1 if this is the last update; 0 otherwise 48 * @return 0 if ok, -1 on error 49 */ 50 int (*hash_update)(struct hash_algo *algo, void *ctx, const void *buf, 51 unsigned int size, int is_last); 52 /* 53 * hash_finish: Write the hash result to the given buffer 54 * 55 * The context is freed by this function. 56 * 57 * @algo: Pointer to the hash_algo struct 58 * @ctx: Pointer to the context for hashing 59 * @dest_buf: Pointer to the buffer for the result 60 * @size: Size of the buffer for the result 61 * @return 0 if ok, -ENOSPC if size of the result buffer is too small 62 * or -1 on other errors 63 */ 64 int (*hash_finish)(struct hash_algo *algo, void *ctx, void *dest_buf, 65 int size); 66 }; 67 68 /* 69 * Maximum digest size for all algorithms we support. Having this value 70 * avoids a malloc() or C99 local declaration in common/cmd_hash.c. 71 */ 72 #define HASH_MAX_DIGEST_SIZE 32 73 74 enum { 75 HASH_FLAG_VERIFY = 1 << 0, /* Enable verify mode */ 76 HASH_FLAG_ENV = 1 << 1, /* Allow env vars */ 77 }; 78 79 /** 80 * hash_command: Process a hash command for a particular algorithm 81 * 82 * This common function is used to implement specific hash commands. 83 * 84 * @algo_name: Hash algorithm being used (lower case!) 85 * @flags: Flags value (HASH_FLAG_...) 86 * @cmdtp: Pointer to command table entry 87 * @flag: Some flags normally 0 (see CMD_FLAG_.. above) 88 * @argc: Number of arguments (arg 0 must be the command text) 89 * @argv: Arguments 90 */ 91 int hash_command(const char *algo_name, int flags, cmd_tbl_t *cmdtp, int flag, 92 int argc, char * const argv[]); 93 94 /** 95 * hash_block() - Hash a block according to the requested algorithm 96 * 97 * The caller probably knows the hash length for the chosen algorithm, but 98 * in order to provide a general interface, and output_size parameter is 99 * provided. 100 * 101 * @algo_name: Hash algorithm to use 102 * @data: Data to hash 103 * @len: Lengh of data to hash in bytes 104 * @output: Place to put hash value 105 * @output_size: On entry, pointer to the number of bytes available in 106 * output. On exit, pointer to the number of bytes used. 107 * If NULL, then it is assumed that the caller has 108 * allocated enough space for the hash. This is possible 109 * since the caller is selecting the algorithm. 110 * @return 0 if ok, -ve on error: -EPROTONOSUPPORT for an unknown algorithm, 111 * -ENOSPC if the output buffer is not large enough. 112 */ 113 int hash_block(const char *algo_name, const void *data, unsigned int len, 114 uint8_t *output, int *output_size); 115 116 /** 117 * hash_lookup_algo() - Look up the hash_algo struct for an algorithm 118 * 119 * The function returns the pointer to the struct or -EPROTONOSUPPORT if the 120 * algorithm is not available. 121 * 122 * @algo_name: Hash algorithm to look up 123 * @algop: Pointer to the hash_algo struct if found 124 * 125 * @return 0 if ok, -EPROTONOSUPPORT for an unknown algorithm. 126 */ 127 int hash_lookup_algo(const char *algo_name, struct hash_algo **algop); 128 #endif 129