| 1 | #include "git-compat-util.h" |
| 2 | #include "hash.h" |
| 3 | #include "hex.h" |
| 4 | |
| 5 | static const struct object_id empty_tree_oid = { |
| 6 | .hash = { |
| 7 | 0x4b, 0x82, 0x5d, 0xc6, 0x42, 0xcb, 0x6e, 0xb9, 0xa0, 0x60, |
| 8 | 0xe5, 0x4b, 0xf8, 0xd6, 0x92, 0x88, 0xfb, 0xee, 0x49, 0x04 |
| 9 | }, |
| 10 | .algo = GIT_HASH_SHA1, |
| 11 | }; |
| 12 | static const struct object_id empty_blob_oid = { |
| 13 | .hash = { |
| 14 | 0xe6, 0x9d, 0xe2, 0x9b, 0xb2, 0xd1, 0xd6, 0x43, 0x4b, 0x8b, |
| 15 | 0x29, 0xae, 0x77, 0x5a, 0xd8, 0xc2, 0xe4, 0x8c, 0x53, 0x91 |
| 16 | }, |
| 17 | .algo = GIT_HASH_SHA1, |
| 18 | }; |
| 19 | static const struct object_id null_oid_sha1 = { |
| 20 | .hash = {0}, |
| 21 | .algo = GIT_HASH_SHA1, |
| 22 | }; |
| 23 | static const struct object_id empty_tree_oid_sha256 = { |
| 24 | .hash = { |
| 25 | 0x6e, 0xf1, 0x9b, 0x41, 0x22, 0x5c, 0x53, 0x69, 0xf1, 0xc1, |
| 26 | 0x04, 0xd4, 0x5d, 0x8d, 0x85, 0xef, 0xa9, 0xb0, 0x57, 0xb5, |
| 27 | 0x3b, 0x14, 0xb4, 0xb9, 0xb9, 0x39, 0xdd, 0x74, 0xde, 0xcc, |
| 28 | 0x53, 0x21 |
| 29 | }, |
| 30 | .algo = GIT_HASH_SHA256, |
| 31 | }; |
| 32 | static const struct object_id empty_blob_oid_sha256 = { |
| 33 | .hash = { |
| 34 | 0x47, 0x3a, 0x0f, 0x4c, 0x3b, 0xe8, 0xa9, 0x36, 0x81, 0xa2, |
| 35 | 0x67, 0xe3, 0xb1, 0xe9, 0xa7, 0xdc, 0xda, 0x11, 0x85, 0x43, |
| 36 | 0x6f, 0xe1, 0x41, 0xf7, 0x74, 0x91, 0x20, 0xa3, 0x03, 0x72, |
| 37 | 0x18, 0x13 |
| 38 | }, |
| 39 | .algo = GIT_HASH_SHA256, |
| 40 | }; |
| 41 | static const struct object_id null_oid_sha256 = { |
| 42 | .hash = {0}, |
| 43 | .algo = GIT_HASH_SHA256, |
| 44 | }; |
| 45 | |
| 46 | static void git_hash_sha1_init(struct git_hash_ctx *ctx) |
| 47 | { |
| 48 | ctx->algop = &hash_algos[GIT_HASH_SHA1]; |
| 49 | git_SHA1_Init(&ctx->state.sha1); |
| 50 | } |
| 51 | |
| 52 | static void git_hash_sha1_clone(struct git_hash_ctx *dst, const struct git_hash_ctx *src) |
| 53 | { |
| 54 | dst->algop = src->algop; |
| 55 | git_SHA1_Clone(&dst->state.sha1, &src->state.sha1); |
| 56 | } |
| 57 | |
| 58 | static void git_hash_sha1_update(struct git_hash_ctx *ctx, const void *data, size_t len) |
| 59 | { |
| 60 | git_SHA1_Update(&ctx->state.sha1, data, len); |
| 61 | } |
| 62 | |
| 63 | static void git_hash_sha1_final(unsigned char *hash, struct git_hash_ctx *ctx) |
| 64 | { |
| 65 | git_SHA1_Final(hash, &ctx->state.sha1); |
| 66 | } |
| 67 | |
| 68 | static void git_hash_sha1_final_oid(struct object_id *oid, struct git_hash_ctx *ctx) |
| 69 | { |
| 70 | git_SHA1_Final(oid->hash, &ctx->state.sha1); |
| 71 | memset(oid->hash + GIT_SHA1_RAWSZ, 0, GIT_MAX_RAWSZ - GIT_SHA1_RAWSZ); |
| 72 | oid->algo = GIT_HASH_SHA1; |
| 73 | } |
| 74 | |
| 75 | static void git_hash_sha1_discard(struct git_hash_ctx *ctx) |
| 76 | { |
| 77 | git_SHA1_Discard(&ctx->state.sha1); |
| 78 | } |
| 79 | |
| 80 | static void git_hash_sha1_init_unsafe(struct git_hash_ctx *ctx) |
| 81 | { |
| 82 | ctx->algop = unsafe_hash_algo(&hash_algos[GIT_HASH_SHA1]); |
| 83 | git_SHA1_Init_unsafe(&ctx->state.sha1_unsafe); |
| 84 | } |
| 85 | |
| 86 | static void git_hash_sha1_clone_unsafe(struct git_hash_ctx *dst, const struct git_hash_ctx *src) |
| 87 | { |
| 88 | dst->algop = src->algop; |
| 89 | git_SHA1_Clone_unsafe(&dst->state.sha1_unsafe, &src->state.sha1_unsafe); |
| 90 | } |
| 91 | |
| 92 | static void git_hash_sha1_update_unsafe(struct git_hash_ctx *ctx, const void *data, |
| 93 | size_t len) |
| 94 | { |
| 95 | git_SHA1_Update_unsafe(&ctx->state.sha1_unsafe, data, len); |
| 96 | } |
| 97 | |
| 98 | static void git_hash_sha1_final_unsafe(unsigned char *hash, struct git_hash_ctx *ctx) |
| 99 | { |
| 100 | git_SHA1_Final_unsafe(hash, &ctx->state.sha1_unsafe); |
| 101 | } |
| 102 | |
| 103 | static void git_hash_sha1_final_oid_unsafe(struct object_id *oid, struct git_hash_ctx *ctx) |
| 104 | { |
| 105 | git_SHA1_Final_unsafe(oid->hash, &ctx->state.sha1_unsafe); |
| 106 | memset(oid->hash + GIT_SHA1_RAWSZ, 0, GIT_MAX_RAWSZ - GIT_SHA1_RAWSZ); |
| 107 | oid->algo = GIT_HASH_SHA1; |
| 108 | } |
| 109 | |
| 110 | static void git_hash_sha1_discard_unsafe(struct git_hash_ctx *ctx) |
| 111 | { |
| 112 | git_SHA1_Discard_unsafe(&ctx->state.sha1_unsafe); |
| 113 | } |
| 114 | |
| 115 | static void git_hash_sha256_init(struct git_hash_ctx *ctx) |
| 116 | { |
| 117 | ctx->algop = unsafe_hash_algo(&hash_algos[GIT_HASH_SHA256]); |
| 118 | git_SHA256_Init(&ctx->state.sha256); |
| 119 | } |
| 120 | |
| 121 | static void git_hash_sha256_clone(struct git_hash_ctx *dst, const struct git_hash_ctx *src) |
| 122 | { |
| 123 | dst->algop = src->algop; |
| 124 | git_SHA256_Clone(&dst->state.sha256, &src->state.sha256); |
| 125 | } |
| 126 | |
| 127 | static void git_hash_sha256_update(struct git_hash_ctx *ctx, const void *data, size_t len) |
| 128 | { |
| 129 | git_SHA256_Update(&ctx->state.sha256, data, len); |
| 130 | } |
| 131 | |
| 132 | static void git_hash_sha256_final(unsigned char *hash, struct git_hash_ctx *ctx) |
| 133 | { |
| 134 | git_SHA256_Final(hash, &ctx->state.sha256); |
| 135 | } |
| 136 | |
| 137 | static void git_hash_sha256_final_oid(struct object_id *oid, struct git_hash_ctx *ctx) |
| 138 | { |
| 139 | git_SHA256_Final(oid->hash, &ctx->state.sha256); |
| 140 | /* |
| 141 | * This currently does nothing, so the compiler should optimize it out, |
| 142 | * but keep it in case we extend the hash size again. |
| 143 | */ |
| 144 | memset(oid->hash + GIT_SHA256_RAWSZ, 0, GIT_MAX_RAWSZ - GIT_SHA256_RAWSZ); |
| 145 | oid->algo = GIT_HASH_SHA256; |
| 146 | } |
| 147 | |
| 148 | static void git_hash_sha256_discard(struct git_hash_ctx *ctx) |
| 149 | { |
| 150 | git_SHA256_Discard(&ctx->state.sha256); |
| 151 | } |
| 152 | |
| 153 | static void git_hash_unknown_init(struct git_hash_ctx *ctx UNUSED) |
| 154 | { |
| 155 | BUG("trying to init unknown hash"); |
| 156 | } |
| 157 | |
| 158 | static void git_hash_unknown_clone(struct git_hash_ctx *dst UNUSED, |
| 159 | const struct git_hash_ctx *src UNUSED) |
| 160 | { |
| 161 | BUG("trying to clone unknown hash"); |
| 162 | } |
| 163 | |
| 164 | static void git_hash_unknown_update(struct git_hash_ctx *ctx UNUSED, |
| 165 | const void *data UNUSED, |
| 166 | size_t len UNUSED) |
| 167 | { |
| 168 | BUG("trying to update unknown hash"); |
| 169 | } |
| 170 | |
| 171 | static void git_hash_unknown_final(unsigned char *hash UNUSED, |
| 172 | struct git_hash_ctx *ctx UNUSED) |
| 173 | { |
| 174 | BUG("trying to finalize unknown hash"); |
| 175 | } |
| 176 | |
| 177 | static void git_hash_unknown_final_oid(struct object_id *oid UNUSED, |
| 178 | struct git_hash_ctx *ctx UNUSED) |
| 179 | { |
| 180 | BUG("trying to finalize unknown hash"); |
| 181 | } |
| 182 | |
| 183 | static void git_hash_unknown_discard(struct git_hash_ctx *ctx UNUSED) |
| 184 | { |
| 185 | BUG("trying to discard unknown hash"); |
| 186 | } |
| 187 | |
| 188 | static const struct git_hash_algo sha1_unsafe_algo = { |
| 189 | .name = "sha1", |
| 190 | .format_id = GIT_SHA1_FORMAT_ID, |
| 191 | .rawsz = GIT_SHA1_RAWSZ, |
| 192 | .hexsz = GIT_SHA1_HEXSZ, |
| 193 | .blksz = GIT_SHA1_BLKSZ, |
| 194 | .init_fn = git_hash_sha1_init_unsafe, |
| 195 | .clone_fn = git_hash_sha1_clone_unsafe, |
| 196 | .update_fn = git_hash_sha1_update_unsafe, |
| 197 | .final_fn = git_hash_sha1_final_unsafe, |
| 198 | .final_oid_fn = git_hash_sha1_final_oid_unsafe, |
| 199 | .discard_fn = git_hash_sha1_discard_unsafe, |
| 200 | .empty_tree = &empty_tree_oid, |
| 201 | .empty_blob = &empty_blob_oid, |
| 202 | .null_oid = &null_oid_sha1, |
| 203 | }; |
| 204 | |
| 205 | const struct git_hash_algo hash_algos[GIT_HASH_NALGOS] = { |
| 206 | { |
| 207 | .name = NULL, |
| 208 | .format_id = 0x00000000, |
| 209 | .rawsz = 0, |
| 210 | .hexsz = 0, |
| 211 | .blksz = 0, |
| 212 | .init_fn = git_hash_unknown_init, |
| 213 | .clone_fn = git_hash_unknown_clone, |
| 214 | .update_fn = git_hash_unknown_update, |
| 215 | .final_fn = git_hash_unknown_final, |
| 216 | .final_oid_fn = git_hash_unknown_final_oid, |
| 217 | .discard_fn = git_hash_unknown_discard, |
| 218 | .empty_tree = NULL, |
| 219 | .empty_blob = NULL, |
| 220 | .null_oid = NULL, |
| 221 | }, |
| 222 | { |
| 223 | .name = "sha1", |
| 224 | .format_id = GIT_SHA1_FORMAT_ID, |
| 225 | .rawsz = GIT_SHA1_RAWSZ, |
| 226 | .hexsz = GIT_SHA1_HEXSZ, |
| 227 | .blksz = GIT_SHA1_BLKSZ, |
| 228 | .init_fn = git_hash_sha1_init, |
| 229 | .clone_fn = git_hash_sha1_clone, |
| 230 | .update_fn = git_hash_sha1_update, |
| 231 | .final_fn = git_hash_sha1_final, |
| 232 | .final_oid_fn = git_hash_sha1_final_oid, |
| 233 | .discard_fn = git_hash_sha1_discard, |
| 234 | .unsafe = &sha1_unsafe_algo, |
| 235 | .empty_tree = &empty_tree_oid, |
| 236 | .empty_blob = &empty_blob_oid, |
| 237 | .null_oid = &null_oid_sha1, |
| 238 | }, |
| 239 | { |
| 240 | .name = "sha256", |
| 241 | .format_id = GIT_SHA256_FORMAT_ID, |
| 242 | .rawsz = GIT_SHA256_RAWSZ, |
| 243 | .hexsz = GIT_SHA256_HEXSZ, |
| 244 | .blksz = GIT_SHA256_BLKSZ, |
| 245 | .init_fn = git_hash_sha256_init, |
| 246 | .clone_fn = git_hash_sha256_clone, |
| 247 | .update_fn = git_hash_sha256_update, |
| 248 | .final_fn = git_hash_sha256_final, |
| 249 | .final_oid_fn = git_hash_sha256_final_oid, |
| 250 | .discard_fn = git_hash_sha256_discard, |
| 251 | .empty_tree = &empty_tree_oid_sha256, |
| 252 | .empty_blob = &empty_blob_oid_sha256, |
| 253 | .null_oid = &null_oid_sha256, |
| 254 | } |
| 255 | }; |
| 256 | |
| 257 | const struct object_id *null_oid(const struct git_hash_algo *algop) |
| 258 | { |
| 259 | return algop->null_oid; |
| 260 | } |
| 261 | |
| 262 | const char *empty_tree_oid_hex(const struct git_hash_algo *algop) |
| 263 | { |
| 264 | static char buf[GIT_MAX_HEXSZ + 1]; |
| 265 | return oid_to_hex_r(buf, algop->empty_tree); |
| 266 | } |
| 267 | |
| 268 | const struct git_hash_algo *hash_algo_ptr_by_number(uint32_t algo) |
| 269 | { |
| 270 | if (algo >= GIT_HASH_NALGOS) |
| 271 | return NULL; |
| 272 | return &hash_algos[algo]; |
| 273 | } |
| 274 | |
| 275 | struct git_hash_ctx *git_hash_alloc(void) |
| 276 | { |
| 277 | return xmalloc(sizeof(struct git_hash_ctx)); |
| 278 | } |
| 279 | |
| 280 | void git_hash_free(struct git_hash_ctx *ctx) |
| 281 | { |
| 282 | free(ctx); |
| 283 | } |
| 284 | |
| 285 | void git_hash_init(struct git_hash_ctx *ctx, const struct git_hash_algo *algop) |
| 286 | { |
| 287 | algop->init_fn(ctx); |
| 288 | ctx->active = true; |
| 289 | } |
| 290 | |
| 291 | void git_hash_clone(struct git_hash_ctx *dst, const struct git_hash_ctx *src) |
| 292 | { |
| 293 | if (!src->active) |
| 294 | BUG("attempt to copy from an inactive hash context"); |
| 295 | if (!dst->active) |
| 296 | BUG("attempt to copy to an inactive hash context"); |
| 297 | src->algop->clone_fn(dst, src); |
| 298 | } |
| 299 | |
| 300 | void git_hash_update(struct git_hash_ctx *ctx, const void *in, size_t len) |
| 301 | { |
| 302 | if (!ctx->active) |
| 303 | BUG("attempt to update an inactive hash context"); |
| 304 | ctx->algop->update_fn(ctx, in, len); |
| 305 | } |
| 306 | |
| 307 | void git_hash_final(unsigned char *hash, struct git_hash_ctx *ctx) |
| 308 | { |
| 309 | if (!ctx->active) |
| 310 | BUG("attempt to finalize an inactive hash context"); |
| 311 | ctx->algop->final_fn(hash, ctx); |
| 312 | ctx->active = false; |
| 313 | } |
| 314 | |
| 315 | void git_hash_final_oid(struct object_id *oid, struct git_hash_ctx *ctx) |
| 316 | { |
| 317 | if (!ctx->active) |
| 318 | BUG("attempt to finalize an inactive hash context"); |
| 319 | ctx->algop->final_oid_fn(oid, ctx); |
| 320 | ctx->active = false; |
| 321 | } |
| 322 | |
| 323 | void git_hash_discard(struct git_hash_ctx *ctx) |
| 324 | { |
| 325 | if (!ctx->active) |
| 326 | return; |
| 327 | ctx->algop->discard_fn(ctx); |
| 328 | ctx->active = false; |
| 329 | } |
| 330 | |
| 331 | uint32_t hash_algo_by_name(const char *name) |
| 332 | { |
| 333 | if (!name) |
| 334 | return GIT_HASH_UNKNOWN; |
| 335 | for (size_t i = 1; i < GIT_HASH_NALGOS; i++) |
| 336 | if (!strcmp(name, hash_algos[i].name)) |
| 337 | return i; |
| 338 | return GIT_HASH_UNKNOWN; |
| 339 | } |
| 340 | |
| 341 | uint32_t hash_algo_by_id(uint32_t format_id) |
| 342 | { |
| 343 | for (size_t i = 1; i < GIT_HASH_NALGOS; i++) |
| 344 | if (format_id == hash_algos[i].format_id) |
| 345 | return i; |
| 346 | return GIT_HASH_UNKNOWN; |
| 347 | } |
| 348 | |
| 349 | uint32_t hash_algo_by_length(size_t len) |
| 350 | { |
| 351 | for (size_t i = 1; i < GIT_HASH_NALGOS; i++) |
| 352 | if (len == hash_algos[i].rawsz) |
| 353 | return i; |
| 354 | return GIT_HASH_UNKNOWN; |
| 355 | } |
| 356 | |
| 357 | const struct git_hash_algo *unsafe_hash_algo(const struct git_hash_algo *algop) |
| 358 | { |
| 359 | /* If we have a faster "unsafe" implementation, use that. */ |
| 360 | if (algop->unsafe) |
| 361 | return algop->unsafe; |
| 362 | /* Otherwise use the default one. */ |
| 363 | return algop; |
| 364 | } |
| 365 | |
| 366 | unsigned oid_common_prefix_hexlen(const struct object_id *a, |
| 367 | const struct object_id *b) |
| 368 | { |
| 369 | unsigned rawsz = hash_algos[a->algo].rawsz; |
| 370 | |
| 371 | for (unsigned i = 0; i < rawsz; i++) { |
| 372 | if (a->hash[i] == b->hash[i]) |
| 373 | continue; |
| 374 | |
| 375 | if ((a->hash[i] ^ b->hash[i]) & 0xf0) |
| 376 | return i * 2; |
| 377 | else |
| 378 | return i * 2 + 1; |
| 379 | } |
| 380 | |
| 381 | return rawsz * 2; |
| 382 | } |