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f18f816c | 1 | #ifndef HASH_H |
2 | #define HASH_H | |
3 | ||
3fa6f2aa | 4 | #include "repository.h" |
f50e766b | 5 | |
9dc523aa | 6 | #if defined(SHA1_APPLE) |
f18f816c | 7 | #include <CommonCrypto/CommonDigest.h> |
8 | #elif defined(SHA1_OPENSSL) | |
9 | #include <openssl/sha.h> | |
8325e43b | 10 | #elif defined(SHA1_DC) |
36f048c5 | 11 | #include "sha1dc_git.h" |
f18f816c | 12 | #else /* SHA1_BLK */ |
13 | #include "block-sha1/sha1.h" | |
14 | #endif | |
15 | ||
e5557358 | 16 | #if defined(SHA256_NETTLE) |
17 | #include "sha256/nettle.h" | |
18 | #elif defined(SHA256_GCRYPT) | |
768e30ea | 19 | #define SHA256_NEEDS_CLONE_HELPER |
27dc04c5 | 20 | #include "sha256/gcrypt.h" |
4b4e2918 | 21 | #elif defined(SHA256_OPENSSL) |
22 | #include <openssl/sha.h> | |
27dc04c5 | 23 | #else |
13eeedb5 | 24 | #include "sha256/block/sha256.h" |
27dc04c5 | 25 | #endif |
13eeedb5 | 26 | |
164e7163 | 27 | #ifndef platform_SHA_CTX |
28 | /* | |
29 | * platform's underlying implementation of SHA-1; could be OpenSSL, | |
b212c0ca | 30 | * blk_SHA, Apple CommonCrypto, etc... Note that the relevant |
31 | * SHA-1 header may have already defined platform_SHA_CTX for our | |
9dc523aa | 32 | * own implementations like block-sha1, so we list |
164e7163 | 33 | * the default for OpenSSL compatible SHA-1 implementations here. |
34 | */ | |
35 | #define platform_SHA_CTX SHA_CTX | |
36 | #define platform_SHA1_Init SHA1_Init | |
37 | #define platform_SHA1_Update SHA1_Update | |
38 | #define platform_SHA1_Final SHA1_Final | |
39 | #endif | |
40 | ||
41 | #define git_SHA_CTX platform_SHA_CTX | |
42 | #define git_SHA1_Init platform_SHA1_Init | |
43 | #define git_SHA1_Update platform_SHA1_Update | |
44 | #define git_SHA1_Final platform_SHA1_Final | |
45 | ||
13eeedb5 | 46 | #ifndef platform_SHA256_CTX |
47 | #define platform_SHA256_CTX SHA256_CTX | |
48 | #define platform_SHA256_Init SHA256_Init | |
49 | #define platform_SHA256_Update SHA256_Update | |
50 | #define platform_SHA256_Final SHA256_Final | |
51 | #endif | |
52 | ||
53 | #define git_SHA256_CTX platform_SHA256_CTX | |
54 | #define git_SHA256_Init platform_SHA256_Init | |
55 | #define git_SHA256_Update platform_SHA256_Update | |
56 | #define git_SHA256_Final platform_SHA256_Final | |
57 | ||
768e30ea | 58 | #ifdef platform_SHA256_Clone |
59 | #define git_SHA256_Clone platform_SHA256_Clone | |
60 | #endif | |
61 | ||
164e7163 | 62 | #ifdef SHA1_MAX_BLOCK_SIZE |
63 | #include "compat/sha1-chunked.h" | |
64 | #undef git_SHA1_Update | |
65 | #define git_SHA1_Update git_SHA1_Update_Chunked | |
66 | #endif | |
67 | ||
768e30ea | 68 | static inline void git_SHA1_Clone(git_SHA_CTX *dst, const git_SHA_CTX *src) |
69 | { | |
70 | memcpy(dst, src, sizeof(*dst)); | |
71 | } | |
72 | ||
73 | #ifndef SHA256_NEEDS_CLONE_HELPER | |
74 | static inline void git_SHA256_Clone(git_SHA256_CTX *dst, const git_SHA256_CTX *src) | |
75 | { | |
76 | memcpy(dst, src, sizeof(*dst)); | |
77 | } | |
78 | #endif | |
79 | ||
f50e766b | 80 | /* |
81 | * Note that these constants are suitable for indexing the hash_algos array and | |
82 | * comparing against each other, but are otherwise arbitrary, so they should not | |
83 | * be exposed to the user or serialized to disk. To know whether a | |
84 | * git_hash_algo struct points to some usable hash function, test the format_id | |
85 | * field for being non-zero. Use the name field for user-visible situations and | |
86 | * the format_id field for fixed-length fields on disk. | |
87 | */ | |
88 | /* An unknown hash function. */ | |
89 | #define GIT_HASH_UNKNOWN 0 | |
90 | /* SHA-1 */ | |
91 | #define GIT_HASH_SHA1 1 | |
13eeedb5 | 92 | /* SHA-256 */ |
93 | #define GIT_HASH_SHA256 2 | |
f50e766b | 94 | /* Number of algorithms supported (including unknown). */ |
13eeedb5 | 95 | #define GIT_HASH_NALGOS (GIT_HASH_SHA256 + 1) |
f50e766b | 96 | |
27f3796a HWN |
97 | /* "sha1", big-endian */ |
98 | #define GIT_SHA1_FORMAT_ID 0x73686131 | |
99 | ||
ab795f0d | 100 | /* The length in bytes and in hex digits of an object name (SHA-1 value). */ |
101 | #define GIT_SHA1_RAWSZ 20 | |
102 | #define GIT_SHA1_HEXSZ (2 * GIT_SHA1_RAWSZ) | |
103 | /* The block size of SHA-1. */ | |
104 | #define GIT_SHA1_BLKSZ 64 | |
105 | ||
27f3796a HWN |
106 | /* "s256", big-endian */ |
107 | #define GIT_SHA256_FORMAT_ID 0x73323536 | |
108 | ||
ab795f0d | 109 | /* The length in bytes and in hex digits of an object name (SHA-256 value). */ |
110 | #define GIT_SHA256_RAWSZ 32 | |
111 | #define GIT_SHA256_HEXSZ (2 * GIT_SHA256_RAWSZ) | |
112 | /* The block size of SHA-256. */ | |
113 | #define GIT_SHA256_BLKSZ 64 | |
114 | ||
115 | /* The length in byte and in hex digits of the largest possible hash value. */ | |
116 | #define GIT_MAX_RAWSZ GIT_SHA256_RAWSZ | |
117 | #define GIT_MAX_HEXSZ GIT_SHA256_HEXSZ | |
118 | /* The largest possible block size for any supported hash. */ | |
119 | #define GIT_MAX_BLKSZ GIT_SHA256_BLKSZ | |
120 | ||
121 | struct object_id { | |
122 | unsigned char hash[GIT_MAX_RAWSZ]; | |
8bcda98d | 123 | int algo; /* XXX requires 4-byte alignment */ |
ab795f0d | 124 | }; |
125 | ||
41227cb1 EN |
126 | #define GET_OID_QUIETLY 01 |
127 | #define GET_OID_COMMIT 02 | |
128 | #define GET_OID_COMMITTISH 04 | |
129 | #define GET_OID_TREE 010 | |
130 | #define GET_OID_TREEISH 020 | |
131 | #define GET_OID_BLOB 040 | |
132 | #define GET_OID_FOLLOW_SYMLINKS 0100 | |
133 | #define GET_OID_RECORD_PATH 0200 | |
134 | #define GET_OID_ONLY_TO_DIE 04000 | |
135 | #define GET_OID_REQUIRE_PATH 010000 | |
136 | ||
137 | #define GET_OID_DISAMBIGUATORS \ | |
138 | (GET_OID_COMMIT | GET_OID_COMMITTISH | \ | |
139 | GET_OID_TREE | GET_OID_TREEISH | \ | |
140 | GET_OID_BLOB) | |
141 | ||
142 | enum get_oid_result { | |
143 | FOUND = 0, | |
144 | MISSING_OBJECT = -1, /* The requested object is missing */ | |
145 | SHORT_NAME_AMBIGUOUS = -2, | |
146 | /* The following only apply when symlinks are followed */ | |
147 | DANGLING_SYMLINK = -4, /* | |
148 | * The initial symlink is there, but | |
149 | * (transitively) points to a missing | |
150 | * in-tree file | |
151 | */ | |
152 | SYMLINK_LOOP = -5, | |
153 | NOT_DIR = -6, /* | |
154 | * Somewhere along the symlink chain, a path is | |
155 | * requested which contains a file as a | |
156 | * non-final element. | |
157 | */ | |
158 | }; | |
159 | ||
ac73cedf | 160 | /* A suitably aligned type for stack allocations of hash contexts. */ |
161 | union git_hash_ctx { | |
162 | git_SHA_CTX sha1; | |
13eeedb5 | 163 | git_SHA256_CTX sha256; |
ac73cedf | 164 | }; |
165 | typedef union git_hash_ctx git_hash_ctx; | |
166 | ||
167 | typedef void (*git_hash_init_fn)(git_hash_ctx *ctx); | |
768e30ea | 168 | typedef void (*git_hash_clone_fn)(git_hash_ctx *dst, const git_hash_ctx *src); |
ac73cedf | 169 | typedef void (*git_hash_update_fn)(git_hash_ctx *ctx, const void *in, size_t len); |
170 | typedef void (*git_hash_final_fn)(unsigned char *hash, git_hash_ctx *ctx); | |
ab795f0d | 171 | typedef void (*git_hash_final_oid_fn)(struct object_id *oid, git_hash_ctx *ctx); |
f50e766b | 172 | |
173 | struct git_hash_algo { | |
174 | /* | |
175 | * The name of the algorithm, as appears in the config file and in | |
176 | * messages. | |
177 | */ | |
178 | const char *name; | |
179 | ||
180 | /* A four-byte version identifier, used in pack indices. */ | |
181 | uint32_t format_id; | |
182 | ||
f50e766b | 183 | /* The length of the hash in binary. */ |
184 | size_t rawsz; | |
185 | ||
186 | /* The length of the hash in hex characters. */ | |
187 | size_t hexsz; | |
188 | ||
a2ce0a75 | 189 | /* The block size of the hash. */ |
190 | size_t blksz; | |
191 | ||
f50e766b | 192 | /* The hash initialization function. */ |
193 | git_hash_init_fn init_fn; | |
194 | ||
768e30ea | 195 | /* The hash context cloning function. */ |
196 | git_hash_clone_fn clone_fn; | |
197 | ||
f50e766b | 198 | /* The hash update function. */ |
199 | git_hash_update_fn update_fn; | |
200 | ||
201 | /* The hash finalization function. */ | |
202 | git_hash_final_fn final_fn; | |
203 | ||
ab795f0d | 204 | /* The hash finalization function for object IDs. */ |
205 | git_hash_final_oid_fn final_oid_fn; | |
206 | ||
f50e766b | 207 | /* The OID of the empty tree. */ |
208 | const struct object_id *empty_tree; | |
209 | ||
210 | /* The OID of the empty blob. */ | |
211 | const struct object_id *empty_blob; | |
14228447 | 212 | |
213 | /* The all-zeros OID. */ | |
214 | const struct object_id *null_oid; | |
f50e766b | 215 | }; |
216 | extern const struct git_hash_algo hash_algos[GIT_HASH_NALGOS]; | |
217 | ||
2f90b9d9 | 218 | /* |
219 | * Return a GIT_HASH_* constant based on the name. Returns GIT_HASH_UNKNOWN if | |
220 | * the name doesn't match a known algorithm. | |
221 | */ | |
222 | int hash_algo_by_name(const char *name); | |
223 | /* Identical, except based on the format ID. */ | |
224 | int hash_algo_by_id(uint32_t format_id); | |
95399788 | 225 | /* Identical, except based on the length. */ |
226 | int hash_algo_by_length(int len); | |
2f90b9d9 | 227 | /* Identical, except for a pointer to struct git_hash_algo. */ |
228 | static inline int hash_algo_by_ptr(const struct git_hash_algo *p) | |
229 | { | |
230 | return p - hash_algos; | |
231 | } | |
232 | ||
c0566d78 JK |
233 | #define the_hash_algo the_repository->hash_algo |
234 | ||
14228447 | 235 | const struct object_id *null_oid(void); |
3fa6f2aa | 236 | |
5a6dce70 | 237 | static inline int hashcmp_algop(const unsigned char *sha1, const unsigned char *sha2, const struct git_hash_algo *algop) |
3fa6f2aa JK |
238 | { |
239 | /* | |
240 | * Teach the compiler that there are only two possibilities of hash size | |
241 | * here, so that it can optimize for this case as much as possible. | |
242 | */ | |
5a6dce70 | 243 | if (algop->rawsz == GIT_MAX_RAWSZ) |
3fa6f2aa JK |
244 | return memcmp(sha1, sha2, GIT_MAX_RAWSZ); |
245 | return memcmp(sha1, sha2, GIT_SHA1_RAWSZ); | |
246 | } | |
247 | ||
5a6dce70 | 248 | static inline int hashcmp(const unsigned char *sha1, const unsigned char *sha2) |
249 | { | |
250 | return hashcmp_algop(sha1, sha2, the_hash_algo); | |
251 | } | |
252 | ||
3fa6f2aa JK |
253 | static inline int oidcmp(const struct object_id *oid1, const struct object_id *oid2) |
254 | { | |
5a6dce70 | 255 | const struct git_hash_algo *algop; |
256 | if (!oid1->algo) | |
257 | algop = the_hash_algo; | |
258 | else | |
259 | algop = &hash_algos[oid1->algo]; | |
260 | return hashcmp_algop(oid1->hash, oid2->hash, algop); | |
3fa6f2aa JK |
261 | } |
262 | ||
5a6dce70 | 263 | static inline int hasheq_algop(const unsigned char *sha1, const unsigned char *sha2, const struct git_hash_algo *algop) |
3fa6f2aa JK |
264 | { |
265 | /* | |
266 | * We write this here instead of deferring to hashcmp so that the | |
267 | * compiler can properly inline it and avoid calling memcmp. | |
268 | */ | |
5a6dce70 | 269 | if (algop->rawsz == GIT_MAX_RAWSZ) |
3fa6f2aa JK |
270 | return !memcmp(sha1, sha2, GIT_MAX_RAWSZ); |
271 | return !memcmp(sha1, sha2, GIT_SHA1_RAWSZ); | |
272 | } | |
273 | ||
5a6dce70 | 274 | static inline int hasheq(const unsigned char *sha1, const unsigned char *sha2) |
275 | { | |
276 | return hasheq_algop(sha1, sha2, the_hash_algo); | |
277 | } | |
278 | ||
3fa6f2aa JK |
279 | static inline int oideq(const struct object_id *oid1, const struct object_id *oid2) |
280 | { | |
5a6dce70 | 281 | const struct git_hash_algo *algop; |
282 | if (!oid1->algo) | |
283 | algop = the_hash_algo; | |
284 | else | |
285 | algop = &hash_algos[oid1->algo]; | |
286 | return hasheq_algop(oid1->hash, oid2->hash, algop); | |
3fa6f2aa JK |
287 | } |
288 | ||
289 | static inline int is_null_oid(const struct object_id *oid) | |
290 | { | |
14228447 | 291 | return oideq(oid, null_oid()); |
3fa6f2aa JK |
292 | } |
293 | ||
294 | static inline void hashcpy(unsigned char *sha_dst, const unsigned char *sha_src) | |
295 | { | |
296 | memcpy(sha_dst, sha_src, the_hash_algo->rawsz); | |
297 | } | |
298 | ||
299 | static inline void oidcpy(struct object_id *dst, const struct object_id *src) | |
300 | { | |
301 | memcpy(dst->hash, src->hash, GIT_MAX_RAWSZ); | |
5a6dce70 | 302 | dst->algo = src->algo; |
3fa6f2aa JK |
303 | } |
304 | ||
3d20ed27 MT |
305 | /* Like oidcpy() but zero-pads the unused bytes in dst's hash array. */ |
306 | static inline void oidcpy_with_padding(struct object_id *dst, | |
90e07f0a | 307 | const struct object_id *src) |
3d20ed27 MT |
308 | { |
309 | size_t hashsz; | |
310 | ||
311 | if (!src->algo) | |
312 | hashsz = the_hash_algo->rawsz; | |
313 | else | |
314 | hashsz = hash_algos[src->algo].rawsz; | |
315 | ||
316 | memcpy(dst->hash, src->hash, hashsz); | |
317 | memset(dst->hash + hashsz, 0, GIT_MAX_RAWSZ - hashsz); | |
318 | dst->algo = src->algo; | |
319 | } | |
320 | ||
3fa6f2aa JK |
321 | static inline struct object_id *oiddup(const struct object_id *src) |
322 | { | |
323 | struct object_id *dst = xmalloc(sizeof(struct object_id)); | |
324 | oidcpy(dst, src); | |
325 | return dst; | |
326 | } | |
327 | ||
328 | static inline void hashclr(unsigned char *hash) | |
329 | { | |
330 | memset(hash, 0, the_hash_algo->rawsz); | |
331 | } | |
332 | ||
333 | static inline void oidclr(struct object_id *oid) | |
334 | { | |
335 | memset(oid->hash, 0, GIT_MAX_RAWSZ); | |
5a6dce70 | 336 | oid->algo = hash_algo_by_ptr(the_hash_algo); |
3fa6f2aa JK |
337 | } |
338 | ||
339 | static inline void oidread(struct object_id *oid, const unsigned char *hash) | |
340 | { | |
341 | memcpy(oid->hash, hash, the_hash_algo->rawsz); | |
5a6dce70 | 342 | oid->algo = hash_algo_by_ptr(the_hash_algo); |
3fa6f2aa JK |
343 | } |
344 | ||
345 | static inline int is_empty_blob_sha1(const unsigned char *sha1) | |
346 | { | |
347 | return hasheq(sha1, the_hash_algo->empty_blob->hash); | |
348 | } | |
349 | ||
350 | static inline int is_empty_blob_oid(const struct object_id *oid) | |
351 | { | |
352 | return oideq(oid, the_hash_algo->empty_blob); | |
353 | } | |
354 | ||
355 | static inline int is_empty_tree_sha1(const unsigned char *sha1) | |
356 | { | |
357 | return hasheq(sha1, the_hash_algo->empty_tree->hash); | |
358 | } | |
359 | ||
360 | static inline int is_empty_tree_oid(const struct object_id *oid) | |
361 | { | |
362 | return oideq(oid, the_hash_algo->empty_tree); | |
363 | } | |
364 | ||
5a6dce70 | 365 | static inline void oid_set_algo(struct object_id *oid, const struct git_hash_algo *algop) |
366 | { | |
367 | oid->algo = hash_algo_by_ptr(algop); | |
368 | } | |
369 | ||
3fa6f2aa JK |
370 | const char *empty_tree_oid_hex(void); |
371 | const char *empty_blob_oid_hex(void); | |
372 | ||
f18f816c | 373 | #endif |