summaryrefslogtreecommitdiffstats
path: root/include/hash.h
blob: 4f9a8cf1db7dcd21afece64a0c5642d59c33e453 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
/*
 * Copyright (c) 2012 The Chromium OS Authors.
 * SPDX-License-Identifier:	GPL-2.0+
 */

#ifndef _HASH_H
#define _HASH_H

/*
 * Maximum digest size for all algorithms we support. Having this value
 * avoids a malloc() or C99 local declaration in common/cmd_hash.c.
 */
#define HASH_MAX_DIGEST_SIZE	32

enum {
	HASH_FLAG_VERIFY	= 1 << 0,	/* Enable verify mode */
	HASH_FLAG_ENV		= 1 << 1,	/* Allow env vars */
};

struct hash_algo {
	const char *name;			/* Name of algorithm */
	int digest_size;			/* Length of digest */
	/**
	 * hash_func_ws: Generic hashing function
	 *
	 * This is the generic prototype for a hashing function. We only
	 * have the watchdog version at present.
	 *
	 * @input:	Input buffer
	 * @ilen:	Input buffer length
	 * @output:	Checksum result (length depends on algorithm)
	 * @chunk_sz:	Trigger watchdog after processing this many bytes
	 */
	void (*hash_func_ws)(const unsigned char *input, unsigned int ilen,
		unsigned char *output, unsigned int chunk_sz);
	int chunk_size;				/* Watchdog chunk size */
	/*
	 * hash_init: Create the context for progressive hashing
	 *
	 * @algo: Pointer to the hash_algo struct
	 * @ctxp: Pointer to the pointer of the context for hashing
	 * @return 0 if ok, -1 on error
	 */
	int (*hash_init)(struct hash_algo *algo, void **ctxp);
	/*
	 * hash_update: Perform hashing on the given buffer
	 *
	 * The context is freed by this function if an error occurs.
	 *
	 * @algo: Pointer to the hash_algo struct
	 * @ctx: Pointer to the context for hashing
	 * @buf: Pointer to the buffer being hashed
	 * @size: Size of the buffer being hashed
	 * @is_last: 1 if this is the last update; 0 otherwise
	 * @return 0 if ok, -1 on error
	 */
	int (*hash_update)(struct hash_algo *algo, void *ctx, const void *buf,
			   unsigned int size, int is_last);
	/*
	 * hash_finish: Write the hash result to the given buffer
	 *
	 * The context is freed by this function.
	 *
	 * @algo: Pointer to the hash_algo struct
	 * @ctx: Pointer to the context for hashing
	 * @dest_buf: Pointer to the buffer for the result
	 * @size: Size of the buffer for the result
	 * @return 0 if ok, -ENOSPC if size of the result buffer is too small
	 *   or -1 on other errors
	 */
	int (*hash_finish)(struct hash_algo *algo, void *ctx, void *dest_buf,
			   int size);
};

#ifndef USE_HOSTCC
/**
 * hash_command: Process a hash command for a particular algorithm
 *
 * This common function is used to implement specific hash commands.
 *
 * @algo_name:		Hash algorithm being used (lower case!)
 * @flags:		Flags value (HASH_FLAG_...)
 * @cmdtp:		Pointer to command table entry
 * @flag:		Some flags normally 0 (see CMD_FLAG_.. above)
 * @argc:		Number of arguments (arg 0 must be the command text)
 * @argv:		Arguments
 */
int hash_command(const char *algo_name, int flags, cmd_tbl_t *cmdtp, int flag,
		 int argc, char * const argv[]);

/**
 * hash_block() - Hash a block according to the requested algorithm
 *
 * The caller probably knows the hash length for the chosen algorithm, but
 * in order to provide a general interface, and output_size parameter is
 * provided.
 *
 * @algo_name:		Hash algorithm to use
 * @data:		Data to hash
 * @len:		Lengh of data to hash in bytes
 * @output:		Place to put hash value
 * @output_size:	On entry, pointer to the number of bytes available in
 *			output. On exit, pointer to the number of bytes used.
 *			If NULL, then it is assumed that the caller has
 *			allocated enough space for the hash. This is possible
 *			since the caller is selecting the algorithm.
 * @return 0 if ok, -ve on error: -EPROTONOSUPPORT for an unknown algorithm,
 * -ENOSPC if the output buffer is not large enough.
 */
int hash_block(const char *algo_name, const void *data, unsigned int len,
	       uint8_t *output, int *output_size);

#endif /* !USE_HOSTCC */

/**
 * hash_lookup_algo() - Look up the hash_algo struct for an algorithm
 *
 * The function returns the pointer to the struct or -EPROTONOSUPPORT if the
 * algorithm is not available.
 *
 * @algo_name: Hash algorithm to look up
 * @algop: Pointer to the hash_algo struct if found
 *
 * @return 0 if ok, -EPROTONOSUPPORT for an unknown algorithm.
 */
int hash_lookup_algo(const char *algo_name, struct hash_algo **algop);

/**
 * hash_progressive_lookup_algo() - Look up hash_algo for prog. hash support
 *
 * The function returns the pointer to the struct or -EPROTONOSUPPORT if the
 * algorithm is not available with progressive hash support.
 *
 * @algo_name: Hash algorithm to look up
 * @algop: Pointer to the hash_algo struct if found
 *
 * @return 0 if ok, -EPROTONOSUPPORT for an unknown algorithm.
 */
int hash_progressive_lookup_algo(const char *algo_name,
				 struct hash_algo **algop);

/**
 * hash_parse_string() - Parse hash string into a binary array
 *
 * The function parses a hash string into a binary array that
 * can for example easily be used to compare to hash values.
 *
 * @algo_name: Hash algorithm to look up
 * @str: Hash string to get parsed
 * @result: Binary array of the parsed hash string
 *
 * @return 0 if ok, -EPROTONOSUPPORT for an unknown algorithm.
 */
int hash_parse_string(const char *algo_name, const char *str, uint8_t *result);

#endif