xref: /openbmc/u-boot/include/hash.h (revision b20c38a9)
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
161