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f18f816c | 1 | #ifndef HASH_H |
2 | #define HASH_H | |
3 | ||
f50e766b | 4 | #include "git-compat-util.h" |
3fa6f2aa | 5 | #include "repository.h" |
f50e766b | 6 | |
f18f816c | 7 | #if defined(SHA1_PPC) |
8 | #include "ppc/sha1.h" | |
9 | #elif defined(SHA1_APPLE) | |
10 | #include <CommonCrypto/CommonDigest.h> | |
11 | #elif defined(SHA1_OPENSSL) | |
12 | #include <openssl/sha.h> | |
8325e43b | 13 | #elif defined(SHA1_DC) |
36f048c5 | 14 | #include "sha1dc_git.h" |
f18f816c | 15 | #else /* SHA1_BLK */ |
16 | #include "block-sha1/sha1.h" | |
17 | #endif | |
18 | ||
27dc04c5 | 19 | #if defined(SHA256_GCRYPT) |
768e30ea | 20 | #define SHA256_NEEDS_CLONE_HELPER |
27dc04c5 | 21 | #include "sha256/gcrypt.h" |
4b4e2918 | 22 | #elif defined(SHA256_OPENSSL) |
23 | #include <openssl/sha.h> | |
27dc04c5 | 24 | #else |
13eeedb5 | 25 | #include "sha256/block/sha256.h" |
27dc04c5 | 26 | #endif |
13eeedb5 | 27 | |
164e7163 | 28 | #ifndef platform_SHA_CTX |
29 | /* | |
30 | * platform's underlying implementation of SHA-1; could be OpenSSL, | |
b212c0ca | 31 | * blk_SHA, Apple CommonCrypto, etc... Note that the relevant |
32 | * SHA-1 header may have already defined platform_SHA_CTX for our | |
164e7163 | 33 | * own implementations like block-sha1 and ppc-sha1, so we list |
34 | * the default for OpenSSL compatible SHA-1 implementations here. | |
35 | */ | |
36 | #define platform_SHA_CTX SHA_CTX | |
37 | #define platform_SHA1_Init SHA1_Init | |
38 | #define platform_SHA1_Update SHA1_Update | |
39 | #define platform_SHA1_Final SHA1_Final | |
40 | #endif | |
41 | ||
42 | #define git_SHA_CTX platform_SHA_CTX | |
43 | #define git_SHA1_Init platform_SHA1_Init | |
44 | #define git_SHA1_Update platform_SHA1_Update | |
45 | #define git_SHA1_Final platform_SHA1_Final | |
46 | ||
13eeedb5 | 47 | #ifndef platform_SHA256_CTX |
48 | #define platform_SHA256_CTX SHA256_CTX | |
49 | #define platform_SHA256_Init SHA256_Init | |
50 | #define platform_SHA256_Update SHA256_Update | |
51 | #define platform_SHA256_Final SHA256_Final | |
52 | #endif | |
53 | ||
54 | #define git_SHA256_CTX platform_SHA256_CTX | |
55 | #define git_SHA256_Init platform_SHA256_Init | |
56 | #define git_SHA256_Update platform_SHA256_Update | |
57 | #define git_SHA256_Final platform_SHA256_Final | |
58 | ||
768e30ea | 59 | #ifdef platform_SHA256_Clone |
60 | #define git_SHA256_Clone platform_SHA256_Clone | |
61 | #endif | |
62 | ||
164e7163 | 63 | #ifdef SHA1_MAX_BLOCK_SIZE |
64 | #include "compat/sha1-chunked.h" | |
65 | #undef git_SHA1_Update | |
66 | #define git_SHA1_Update git_SHA1_Update_Chunked | |
67 | #endif | |
68 | ||
768e30ea | 69 | static inline void git_SHA1_Clone(git_SHA_CTX *dst, const git_SHA_CTX *src) |
70 | { | |
71 | memcpy(dst, src, sizeof(*dst)); | |
72 | } | |
73 | ||
74 | #ifndef SHA256_NEEDS_CLONE_HELPER | |
75 | static inline void git_SHA256_Clone(git_SHA256_CTX *dst, const git_SHA256_CTX *src) | |
76 | { | |
77 | memcpy(dst, src, sizeof(*dst)); | |
78 | } | |
79 | #endif | |
80 | ||
f50e766b | 81 | /* |
82 | * Note that these constants are suitable for indexing the hash_algos array and | |
83 | * comparing against each other, but are otherwise arbitrary, so they should not | |
84 | * be exposed to the user or serialized to disk. To know whether a | |
85 | * git_hash_algo struct points to some usable hash function, test the format_id | |
86 | * field for being non-zero. Use the name field for user-visible situations and | |
87 | * the format_id field for fixed-length fields on disk. | |
88 | */ | |
89 | /* An unknown hash function. */ | |
90 | #define GIT_HASH_UNKNOWN 0 | |
91 | /* SHA-1 */ | |
92 | #define GIT_HASH_SHA1 1 | |
13eeedb5 | 93 | /* SHA-256 */ |
94 | #define GIT_HASH_SHA256 2 | |
f50e766b | 95 | /* Number of algorithms supported (including unknown). */ |
13eeedb5 | 96 | #define GIT_HASH_NALGOS (GIT_HASH_SHA256 + 1) |
f50e766b | 97 | |
27f3796a HWN |
98 | /* "sha1", big-endian */ |
99 | #define GIT_SHA1_FORMAT_ID 0x73686131 | |
100 | ||
ab795f0d | 101 | /* The length in bytes and in hex digits of an object name (SHA-1 value). */ |
102 | #define GIT_SHA1_RAWSZ 20 | |
103 | #define GIT_SHA1_HEXSZ (2 * GIT_SHA1_RAWSZ) | |
104 | /* The block size of SHA-1. */ | |
105 | #define GIT_SHA1_BLKSZ 64 | |
106 | ||
27f3796a HWN |
107 | /* "s256", big-endian */ |
108 | #define GIT_SHA256_FORMAT_ID 0x73323536 | |
109 | ||
ab795f0d | 110 | /* The length in bytes and in hex digits of an object name (SHA-256 value). */ |
111 | #define GIT_SHA256_RAWSZ 32 | |
112 | #define GIT_SHA256_HEXSZ (2 * GIT_SHA256_RAWSZ) | |
113 | /* The block size of SHA-256. */ | |
114 | #define GIT_SHA256_BLKSZ 64 | |
115 | ||
116 | /* The length in byte and in hex digits of the largest possible hash value. */ | |
117 | #define GIT_MAX_RAWSZ GIT_SHA256_RAWSZ | |
118 | #define GIT_MAX_HEXSZ GIT_SHA256_HEXSZ | |
119 | /* The largest possible block size for any supported hash. */ | |
120 | #define GIT_MAX_BLKSZ GIT_SHA256_BLKSZ | |
121 | ||
122 | struct object_id { | |
123 | unsigned char hash[GIT_MAX_RAWSZ]; | |
8bcda98d | 124 | int algo; /* XXX requires 4-byte alignment */ |
ab795f0d | 125 | }; |
126 | ||
ac73cedf | 127 | /* A suitably aligned type for stack allocations of hash contexts. */ |
128 | union git_hash_ctx { | |
129 | git_SHA_CTX sha1; | |
13eeedb5 | 130 | git_SHA256_CTX sha256; |
ac73cedf | 131 | }; |
132 | typedef union git_hash_ctx git_hash_ctx; | |
133 | ||
134 | typedef void (*git_hash_init_fn)(git_hash_ctx *ctx); | |
768e30ea | 135 | typedef void (*git_hash_clone_fn)(git_hash_ctx *dst, const git_hash_ctx *src); |
ac73cedf | 136 | typedef void (*git_hash_update_fn)(git_hash_ctx *ctx, const void *in, size_t len); |
137 | typedef void (*git_hash_final_fn)(unsigned char *hash, git_hash_ctx *ctx); | |
ab795f0d | 138 | typedef void (*git_hash_final_oid_fn)(struct object_id *oid, git_hash_ctx *ctx); |
f50e766b | 139 | |
140 | struct git_hash_algo { | |
141 | /* | |
142 | * The name of the algorithm, as appears in the config file and in | |
143 | * messages. | |
144 | */ | |
145 | const char *name; | |
146 | ||
147 | /* A four-byte version identifier, used in pack indices. */ | |
148 | uint32_t format_id; | |
149 | ||
f50e766b | 150 | /* The length of the hash in binary. */ |
151 | size_t rawsz; | |
152 | ||
153 | /* The length of the hash in hex characters. */ | |
154 | size_t hexsz; | |
155 | ||
a2ce0a75 | 156 | /* The block size of the hash. */ |
157 | size_t blksz; | |
158 | ||
f50e766b | 159 | /* The hash initialization function. */ |
160 | git_hash_init_fn init_fn; | |
161 | ||
768e30ea | 162 | /* The hash context cloning function. */ |
163 | git_hash_clone_fn clone_fn; | |
164 | ||
f50e766b | 165 | /* The hash update function. */ |
166 | git_hash_update_fn update_fn; | |
167 | ||
168 | /* The hash finalization function. */ | |
169 | git_hash_final_fn final_fn; | |
170 | ||
ab795f0d | 171 | /* The hash finalization function for object IDs. */ |
172 | git_hash_final_oid_fn final_oid_fn; | |
173 | ||
f50e766b | 174 | /* The OID of the empty tree. */ |
175 | const struct object_id *empty_tree; | |
176 | ||
177 | /* The OID of the empty blob. */ | |
178 | const struct object_id *empty_blob; | |
14228447 | 179 | |
180 | /* The all-zeros OID. */ | |
181 | const struct object_id *null_oid; | |
f50e766b | 182 | }; |
183 | extern const struct git_hash_algo hash_algos[GIT_HASH_NALGOS]; | |
184 | ||
2f90b9d9 | 185 | /* |
186 | * Return a GIT_HASH_* constant based on the name. Returns GIT_HASH_UNKNOWN if | |
187 | * the name doesn't match a known algorithm. | |
188 | */ | |
189 | int hash_algo_by_name(const char *name); | |
190 | /* Identical, except based on the format ID. */ | |
191 | int hash_algo_by_id(uint32_t format_id); | |
95399788 | 192 | /* Identical, except based on the length. */ |
193 | int hash_algo_by_length(int len); | |
2f90b9d9 | 194 | /* Identical, except for a pointer to struct git_hash_algo. */ |
195 | static inline int hash_algo_by_ptr(const struct git_hash_algo *p) | |
196 | { | |
197 | return p - hash_algos; | |
198 | } | |
199 | ||
c0566d78 JK |
200 | #define the_hash_algo the_repository->hash_algo |
201 | ||
14228447 | 202 | const struct object_id *null_oid(void); |
3fa6f2aa | 203 | |
5a6dce70 | 204 | static inline int hashcmp_algop(const unsigned char *sha1, const unsigned char *sha2, const struct git_hash_algo *algop) |
3fa6f2aa JK |
205 | { |
206 | /* | |
207 | * Teach the compiler that there are only two possibilities of hash size | |
208 | * here, so that it can optimize for this case as much as possible. | |
209 | */ | |
5a6dce70 | 210 | if (algop->rawsz == GIT_MAX_RAWSZ) |
3fa6f2aa JK |
211 | return memcmp(sha1, sha2, GIT_MAX_RAWSZ); |
212 | return memcmp(sha1, sha2, GIT_SHA1_RAWSZ); | |
213 | } | |
214 | ||
5a6dce70 | 215 | static inline int hashcmp(const unsigned char *sha1, const unsigned char *sha2) |
216 | { | |
217 | return hashcmp_algop(sha1, sha2, the_hash_algo); | |
218 | } | |
219 | ||
3fa6f2aa JK |
220 | static inline int oidcmp(const struct object_id *oid1, const struct object_id *oid2) |
221 | { | |
5a6dce70 | 222 | const struct git_hash_algo *algop; |
223 | if (!oid1->algo) | |
224 | algop = the_hash_algo; | |
225 | else | |
226 | algop = &hash_algos[oid1->algo]; | |
227 | return hashcmp_algop(oid1->hash, oid2->hash, algop); | |
3fa6f2aa JK |
228 | } |
229 | ||
5a6dce70 | 230 | static inline int hasheq_algop(const unsigned char *sha1, const unsigned char *sha2, const struct git_hash_algo *algop) |
3fa6f2aa JK |
231 | { |
232 | /* | |
233 | * We write this here instead of deferring to hashcmp so that the | |
234 | * compiler can properly inline it and avoid calling memcmp. | |
235 | */ | |
5a6dce70 | 236 | if (algop->rawsz == GIT_MAX_RAWSZ) |
3fa6f2aa JK |
237 | return !memcmp(sha1, sha2, GIT_MAX_RAWSZ); |
238 | return !memcmp(sha1, sha2, GIT_SHA1_RAWSZ); | |
239 | } | |
240 | ||
5a6dce70 | 241 | static inline int hasheq(const unsigned char *sha1, const unsigned char *sha2) |
242 | { | |
243 | return hasheq_algop(sha1, sha2, the_hash_algo); | |
244 | } | |
245 | ||
3fa6f2aa JK |
246 | static inline int oideq(const struct object_id *oid1, const struct object_id *oid2) |
247 | { | |
5a6dce70 | 248 | const struct git_hash_algo *algop; |
249 | if (!oid1->algo) | |
250 | algop = the_hash_algo; | |
251 | else | |
252 | algop = &hash_algos[oid1->algo]; | |
253 | return hasheq_algop(oid1->hash, oid2->hash, algop); | |
3fa6f2aa JK |
254 | } |
255 | ||
256 | static inline int is_null_oid(const struct object_id *oid) | |
257 | { | |
14228447 | 258 | return oideq(oid, null_oid()); |
3fa6f2aa JK |
259 | } |
260 | ||
261 | static inline void hashcpy(unsigned char *sha_dst, const unsigned char *sha_src) | |
262 | { | |
263 | memcpy(sha_dst, sha_src, the_hash_algo->rawsz); | |
264 | } | |
265 | ||
266 | static inline void oidcpy(struct object_id *dst, const struct object_id *src) | |
267 | { | |
268 | memcpy(dst->hash, src->hash, GIT_MAX_RAWSZ); | |
5a6dce70 | 269 | dst->algo = src->algo; |
3fa6f2aa JK |
270 | } |
271 | ||
3d20ed27 MT |
272 | /* Like oidcpy() but zero-pads the unused bytes in dst's hash array. */ |
273 | static inline void oidcpy_with_padding(struct object_id *dst, | |
90e07f0a | 274 | const struct object_id *src) |
3d20ed27 MT |
275 | { |
276 | size_t hashsz; | |
277 | ||
278 | if (!src->algo) | |
279 | hashsz = the_hash_algo->rawsz; | |
280 | else | |
281 | hashsz = hash_algos[src->algo].rawsz; | |
282 | ||
283 | memcpy(dst->hash, src->hash, hashsz); | |
284 | memset(dst->hash + hashsz, 0, GIT_MAX_RAWSZ - hashsz); | |
285 | dst->algo = src->algo; | |
286 | } | |
287 | ||
3fa6f2aa JK |
288 | static inline struct object_id *oiddup(const struct object_id *src) |
289 | { | |
290 | struct object_id *dst = xmalloc(sizeof(struct object_id)); | |
291 | oidcpy(dst, src); | |
292 | return dst; | |
293 | } | |
294 | ||
295 | static inline void hashclr(unsigned char *hash) | |
296 | { | |
297 | memset(hash, 0, the_hash_algo->rawsz); | |
298 | } | |
299 | ||
300 | static inline void oidclr(struct object_id *oid) | |
301 | { | |
302 | memset(oid->hash, 0, GIT_MAX_RAWSZ); | |
5a6dce70 | 303 | oid->algo = hash_algo_by_ptr(the_hash_algo); |
3fa6f2aa JK |
304 | } |
305 | ||
306 | static inline void oidread(struct object_id *oid, const unsigned char *hash) | |
307 | { | |
308 | memcpy(oid->hash, hash, the_hash_algo->rawsz); | |
5a6dce70 | 309 | oid->algo = hash_algo_by_ptr(the_hash_algo); |
3fa6f2aa JK |
310 | } |
311 | ||
312 | static inline int is_empty_blob_sha1(const unsigned char *sha1) | |
313 | { | |
314 | return hasheq(sha1, the_hash_algo->empty_blob->hash); | |
315 | } | |
316 | ||
317 | static inline int is_empty_blob_oid(const struct object_id *oid) | |
318 | { | |
319 | return oideq(oid, the_hash_algo->empty_blob); | |
320 | } | |
321 | ||
322 | static inline int is_empty_tree_sha1(const unsigned char *sha1) | |
323 | { | |
324 | return hasheq(sha1, the_hash_algo->empty_tree->hash); | |
325 | } | |
326 | ||
327 | static inline int is_empty_tree_oid(const struct object_id *oid) | |
328 | { | |
329 | return oideq(oid, the_hash_algo->empty_tree); | |
330 | } | |
331 | ||
5a6dce70 | 332 | static inline void oid_set_algo(struct object_id *oid, const struct git_hash_algo *algop) |
333 | { | |
334 | oid->algo = hash_algo_by_ptr(algop); | |
335 | } | |
336 | ||
3fa6f2aa JK |
337 | const char *empty_tree_oid_hex(void); |
338 | const char *empty_blob_oid_hex(void); | |
339 | ||
f18f816c | 340 | #endif |