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