ci: run `hdr-check` as part of the `Static Analysis` job
[git/git.git] / hash.h
1 #ifndef HASH_H
2 #define HASH_H
3
4 #include "git-compat-util.h"
5
6 #if defined(SHA1_PPC)
7 #include "ppc/sha1.h"
8 #elif defined(SHA1_APPLE)
9 #include <CommonCrypto/CommonDigest.h>
10 #elif defined(SHA1_OPENSSL)
11 #include <openssl/sha.h>
12 #elif defined(SHA1_DC)
13 #include "sha1dc_git.h"
14 #else /* SHA1_BLK */
15 #include "block-sha1/sha1.h"
16 #endif
17
18 #if defined(SHA256_GCRYPT)
19 #include "sha256/gcrypt.h"
20 #elif defined(SHA256_OPENSSL)
21 #include <openssl/sha.h>
22 #else
23 #include "sha256/block/sha256.h"
24 #endif
25
26 #ifndef platform_SHA_CTX
27 /*
28 * platform's underlying implementation of SHA-1; could be OpenSSL,
29 * blk_SHA, Apple CommonCrypto, etc... Note that the relevant
30 * SHA-1 header may have already defined platform_SHA_CTX for our
31 * own implementations like block-sha1 and ppc-sha1, so we list
32 * the default for OpenSSL compatible SHA-1 implementations here.
33 */
34 #define platform_SHA_CTX SHA_CTX
35 #define platform_SHA1_Init SHA1_Init
36 #define platform_SHA1_Update SHA1_Update
37 #define platform_SHA1_Final SHA1_Final
38 #endif
39
40 #define git_SHA_CTX platform_SHA_CTX
41 #define git_SHA1_Init platform_SHA1_Init
42 #define git_SHA1_Update platform_SHA1_Update
43 #define git_SHA1_Final platform_SHA1_Final
44
45 #ifndef platform_SHA256_CTX
46 #define platform_SHA256_CTX SHA256_CTX
47 #define platform_SHA256_Init SHA256_Init
48 #define platform_SHA256_Update SHA256_Update
49 #define platform_SHA256_Final SHA256_Final
50 #endif
51
52 #define git_SHA256_CTX platform_SHA256_CTX
53 #define git_SHA256_Init platform_SHA256_Init
54 #define git_SHA256_Update platform_SHA256_Update
55 #define git_SHA256_Final platform_SHA256_Final
56
57 #ifdef SHA1_MAX_BLOCK_SIZE
58 #include "compat/sha1-chunked.h"
59 #undef git_SHA1_Update
60 #define git_SHA1_Update git_SHA1_Update_Chunked
61 #endif
62
63 /*
64 * Note that these constants are suitable for indexing the hash_algos array and
65 * comparing against each other, but are otherwise arbitrary, so they should not
66 * be exposed to the user or serialized to disk. To know whether a
67 * git_hash_algo struct points to some usable hash function, test the format_id
68 * field for being non-zero. Use the name field for user-visible situations and
69 * the format_id field for fixed-length fields on disk.
70 */
71 /* An unknown hash function. */
72 #define GIT_HASH_UNKNOWN 0
73 /* SHA-1 */
74 #define GIT_HASH_SHA1 1
75 /* SHA-256 */
76 #define GIT_HASH_SHA256 2
77 /* Number of algorithms supported (including unknown). */
78 #define GIT_HASH_NALGOS (GIT_HASH_SHA256 + 1)
79
80 /* A suitably aligned type for stack allocations of hash contexts. */
81 union git_hash_ctx {
82 git_SHA_CTX sha1;
83 git_SHA256_CTX sha256;
84 };
85 typedef union git_hash_ctx git_hash_ctx;
86
87 typedef void (*git_hash_init_fn)(git_hash_ctx *ctx);
88 typedef void (*git_hash_update_fn)(git_hash_ctx *ctx, const void *in, size_t len);
89 typedef void (*git_hash_final_fn)(unsigned char *hash, git_hash_ctx *ctx);
90
91 struct git_hash_algo {
92 /*
93 * The name of the algorithm, as appears in the config file and in
94 * messages.
95 */
96 const char *name;
97
98 /* A four-byte version identifier, used in pack indices. */
99 uint32_t format_id;
100
101 /* The length of the hash in binary. */
102 size_t rawsz;
103
104 /* The length of the hash in hex characters. */
105 size_t hexsz;
106
107 /* The block size of the hash. */
108 size_t blksz;
109
110 /* The hash initialization function. */
111 git_hash_init_fn init_fn;
112
113 /* The hash update function. */
114 git_hash_update_fn update_fn;
115
116 /* The hash finalization function. */
117 git_hash_final_fn final_fn;
118
119 /* The OID of the empty tree. */
120 const struct object_id *empty_tree;
121
122 /* The OID of the empty blob. */
123 const struct object_id *empty_blob;
124 };
125 extern const struct git_hash_algo hash_algos[GIT_HASH_NALGOS];
126
127 /*
128 * Return a GIT_HASH_* constant based on the name. Returns GIT_HASH_UNKNOWN if
129 * the name doesn't match a known algorithm.
130 */
131 int hash_algo_by_name(const char *name);
132 /* Identical, except based on the format ID. */
133 int hash_algo_by_id(uint32_t format_id);
134 /* Identical, except based on the length. */
135 int hash_algo_by_length(int len);
136 /* Identical, except for a pointer to struct git_hash_algo. */
137 static inline int hash_algo_by_ptr(const struct git_hash_algo *p)
138 {
139 return p - hash_algos;
140 }
141
142 /* The length in bytes and in hex digits of an object name (SHA-1 value). */
143 #define GIT_SHA1_RAWSZ 20
144 #define GIT_SHA1_HEXSZ (2 * GIT_SHA1_RAWSZ)
145 /* The block size of SHA-1. */
146 #define GIT_SHA1_BLKSZ 64
147
148 /* The length in bytes and in hex digits of an object name (SHA-256 value). */
149 #define GIT_SHA256_RAWSZ 32
150 #define GIT_SHA256_HEXSZ (2 * GIT_SHA256_RAWSZ)
151 /* The block size of SHA-256. */
152 #define GIT_SHA256_BLKSZ 64
153
154 /* The length in byte and in hex digits of the largest possible hash value. */
155 #define GIT_MAX_RAWSZ GIT_SHA256_RAWSZ
156 #define GIT_MAX_HEXSZ GIT_SHA256_HEXSZ
157 /* The largest possible block size for any supported hash. */
158 #define GIT_MAX_BLKSZ GIT_SHA256_BLKSZ
159
160 struct object_id {
161 unsigned char hash[GIT_MAX_RAWSZ];
162 };
163
164 #define the_hash_algo the_repository->hash_algo
165
166 #endif