xref: /openbmc/u-boot/include/hash.h (revision 7d89982b)
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 #ifndef USE_HOSTCC
21 #if defined(CONFIG_SHA1SUM_VERIFY) || defined(CONFIG_CRC32_VERIFY)
22 #define CONFIG_HASH_VERIFY
23 #endif
24 
25 struct hash_algo {
26 	const char *name;			/* Name of algorithm */
27 	int digest_size;			/* Length of digest */
28 	/**
29 	 * hash_func_ws: Generic hashing function
30 	 *
31 	 * This is the generic prototype for a hashing function. We only
32 	 * have the watchdog version at present.
33 	 *
34 	 * @input:	Input buffer
35 	 * @ilen:	Input buffer length
36 	 * @output:	Checksum result (length depends on algorithm)
37 	 * @chunk_sz:	Trigger watchdog after processing this many bytes
38 	 */
39 	void (*hash_func_ws)(const unsigned char *input, unsigned int ilen,
40 		unsigned char *output, unsigned int chunk_sz);
41 	int chunk_size;				/* Watchdog chunk size */
42 	/*
43 	 * hash_init: Create the context for progressive hashing
44 	 *
45 	 * @algo: Pointer to the hash_algo struct
46 	 * @ctxp: Pointer to the pointer of the context for hashing
47 	 * @return 0 if ok, -1 on error
48 	 */
49 	int (*hash_init)(struct hash_algo *algo, void **ctxp);
50 	/*
51 	 * hash_update: Perform hashing on the given buffer
52 	 *
53 	 * The context is freed by this function if an error occurs.
54 	 *
55 	 * @algo: Pointer to the hash_algo struct
56 	 * @ctx: Pointer to the context for hashing
57 	 * @buf: Pointer to the buffer being hashed
58 	 * @size: Size of the buffer being hashed
59 	 * @is_last: 1 if this is the last update; 0 otherwise
60 	 * @return 0 if ok, -1 on error
61 	 */
62 	int (*hash_update)(struct hash_algo *algo, void *ctx, const void *buf,
63 			   unsigned int size, int is_last);
64 	/*
65 	 * hash_finish: Write the hash result to the given buffer
66 	 *
67 	 * The context is freed by this function.
68 	 *
69 	 * @algo: Pointer to the hash_algo struct
70 	 * @ctx: Pointer to the context for hashing
71 	 * @dest_buf: Pointer to the buffer for the result
72 	 * @size: Size of the buffer for the result
73 	 * @return 0 if ok, -ENOSPC if size of the result buffer is too small
74 	 *   or -1 on other errors
75 	 */
76 	int (*hash_finish)(struct hash_algo *algo, void *ctx, void *dest_buf,
77 			   int size);
78 };
79 
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 /**
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_show() - Print out a hash algorithm and value
132  *
133  * You will get a message like this (without a newline at the end):
134  *
135  * "sha1 for 9eb3337c ... 9eb3338f ==> 7942ef1df479fd3130f716eb9613d107dab7e257"
136  *
137  * @algo:		Algorithm used for hash
138  * @addr:		Address of data that was hashed
139  * @len:		Length of data that was hashed
140  * @output:		Hash value to display
141  */
142 void hash_show(struct hash_algo *algo, ulong addr, ulong len, u8 *output);
143 #endif /* !USE_HOSTCC */
144 #endif
145