| #ifndef HASH_H |
| #define HASH_H |
| |
| #if defined(SHA1_APPLE) |
| #include <CommonCrypto/CommonDigest.h> |
| #elif defined(SHA1_OPENSSL) |
| # include <openssl/sha.h> |
| # if defined(OPENSSL_API_LEVEL) && OPENSSL_API_LEVEL >= 3 |
| # define SHA1_NEEDS_CLONE_HELPER |
| # include "sha1/openssl.h" |
| # endif |
| #elif defined(SHA1_DC) |
| #include "sha1dc_git.h" |
| #else /* SHA1_BLK */ |
| #include "block-sha1/sha1.h" |
| #endif |
| |
| #if defined(SHA1_APPLE_UNSAFE) |
| # include <CommonCrypto/CommonDigest.h> |
| # define platform_SHA_CTX_unsafe CC_SHA1_CTX |
| # define platform_SHA1_Init_unsafe CC_SHA1_Init |
| # define platform_SHA1_Update_unsafe CC_SHA1_Update |
| # define platform_SHA1_Final_unsafe CC_SHA1_Final |
| #elif defined(SHA1_OPENSSL_UNSAFE) |
| # include <openssl/sha.h> |
| # if defined(OPENSSL_API_LEVEL) && OPENSSL_API_LEVEL >= 3 |
| # define SHA1_NEEDS_CLONE_HELPER_UNSAFE |
| # include "sha1/openssl.h" |
| # define platform_SHA_CTX_unsafe openssl_SHA1_CTX |
| # define platform_SHA1_Init_unsafe openssl_SHA1_Init |
| # define platform_SHA1_Clone_unsafe openssl_SHA1_Clone |
| # define platform_SHA1_Update_unsafe openssl_SHA1_Update |
| # define platform_SHA1_Final_unsafe openssl_SHA1_Final |
| # else |
| # define platform_SHA_CTX_unsafe SHA_CTX |
| # define platform_SHA1_Init_unsafe SHA1_Init |
| # define platform_SHA1_Update_unsafe SHA1_Update |
| # define platform_SHA1_Final_unsafe SHA1_Final |
| # endif |
| #elif defined(SHA1_BLK_UNSAFE) |
| # include "block-sha1/sha1.h" |
| # define platform_SHA_CTX_unsafe blk_SHA_CTX |
| # define platform_SHA1_Init_unsafe blk_SHA1_Init |
| # define platform_SHA1_Update_unsafe blk_SHA1_Update |
| # define platform_SHA1_Final_unsafe blk_SHA1_Final |
| #endif |
| |
| #if defined(SHA256_NETTLE) |
| #include "sha256/nettle.h" |
| #elif defined(SHA256_GCRYPT) |
| #define SHA256_NEEDS_CLONE_HELPER |
| #include "sha256/gcrypt.h" |
| #elif defined(SHA256_OPENSSL) |
| # include <openssl/sha.h> |
| # if defined(OPENSSL_API_LEVEL) && OPENSSL_API_LEVEL >= 3 |
| # define SHA256_NEEDS_CLONE_HELPER |
| # include "sha256/openssl.h" |
| # endif |
| #else |
| #include "sha256/block/sha256.h" |
| #endif |
| |
| #ifndef platform_SHA_CTX |
| /* |
| * platform's underlying implementation of SHA-1; could be OpenSSL, |
| * blk_SHA, Apple CommonCrypto, etc... Note that the relevant |
| * SHA-1 header may have already defined platform_SHA_CTX for our |
| * own implementations like block-sha1, so we list |
| * the default for OpenSSL compatible SHA-1 implementations here. |
| */ |
| #define platform_SHA_CTX SHA_CTX |
| #define platform_SHA1_Init SHA1_Init |
| #define platform_SHA1_Update SHA1_Update |
| #define platform_SHA1_Final SHA1_Final |
| #endif |
| |
| #ifndef platform_SHA_CTX_unsafe |
| # define platform_SHA_CTX_unsafe platform_SHA_CTX |
| # define platform_SHA1_Init_unsafe platform_SHA1_Init |
| # define platform_SHA1_Update_unsafe platform_SHA1_Update |
| # define platform_SHA1_Final_unsafe platform_SHA1_Final |
| # ifdef platform_SHA1_Clone |
| # define platform_SHA1_Clone_unsafe platform_SHA1_Clone |
| # endif |
| # ifdef SHA1_NEEDS_CLONE_HELPER |
| # define SHA1_NEEDS_CLONE_HELPER_UNSAFE |
| # endif |
| #endif |
| |
| #define git_SHA_CTX platform_SHA_CTX |
| #define git_SHA1_Init platform_SHA1_Init |
| #define git_SHA1_Update platform_SHA1_Update |
| #define git_SHA1_Final platform_SHA1_Final |
| |
| #define git_SHA_CTX_unsafe platform_SHA_CTX_unsafe |
| #define git_SHA1_Init_unsafe platform_SHA1_Init_unsafe |
| #define git_SHA1_Update_unsafe platform_SHA1_Update_unsafe |
| #define git_SHA1_Final_unsafe platform_SHA1_Final_unsafe |
| |
| #ifdef platform_SHA1_Clone |
| #define git_SHA1_Clone platform_SHA1_Clone |
| #endif |
| #ifdef platform_SHA1_Clone_unsafe |
| # define git_SHA1_Clone_unsafe platform_SHA1_Clone_unsafe |
| #endif |
| |
| #ifndef platform_SHA256_CTX |
| #define platform_SHA256_CTX SHA256_CTX |
| #define platform_SHA256_Init SHA256_Init |
| #define platform_SHA256_Update SHA256_Update |
| #define platform_SHA256_Final SHA256_Final |
| #endif |
| |
| #define git_SHA256_CTX platform_SHA256_CTX |
| #define git_SHA256_Init platform_SHA256_Init |
| #define git_SHA256_Update platform_SHA256_Update |
| #define git_SHA256_Final platform_SHA256_Final |
| |
| #ifdef platform_SHA256_Clone |
| #define git_SHA256_Clone platform_SHA256_Clone |
| #endif |
| |
| #ifdef SHA1_MAX_BLOCK_SIZE |
| #include "compat/sha1-chunked.h" |
| #undef git_SHA1_Update |
| #define git_SHA1_Update git_SHA1_Update_Chunked |
| #endif |
| |
| #ifndef SHA1_NEEDS_CLONE_HELPER |
| static inline void git_SHA1_Clone(git_SHA_CTX *dst, const git_SHA_CTX *src) |
| { |
| memcpy(dst, src, sizeof(*dst)); |
| } |
| #endif |
| #ifndef SHA1_NEEDS_CLONE_HELPER_UNSAFE |
| static inline void git_SHA1_Clone_unsafe(git_SHA_CTX_unsafe *dst, |
| const git_SHA_CTX_unsafe *src) |
| { |
| memcpy(dst, src, sizeof(*dst)); |
| } |
| #endif |
| |
| #ifndef SHA256_NEEDS_CLONE_HELPER |
| static inline void git_SHA256_Clone(git_SHA256_CTX *dst, const git_SHA256_CTX *src) |
| { |
| memcpy(dst, src, sizeof(*dst)); |
| } |
| #endif |
| |
| /* |
| * Note that these constants are suitable for indexing the hash_algos array and |
| * comparing against each other, but are otherwise arbitrary, so they should not |
| * be exposed to the user or serialized to disk. To know whether a |
| * git_hash_algo struct points to some usable hash function, test the format_id |
| * field for being non-zero. Use the name field for user-visible situations and |
| * the format_id field for fixed-length fields on disk. |
| */ |
| /* An unknown hash function. */ |
| #define GIT_HASH_UNKNOWN 0 |
| /* SHA-1 */ |
| #define GIT_HASH_SHA1 1 |
| /* SHA-256 */ |
| #define GIT_HASH_SHA256 2 |
| /* Number of algorithms supported (including unknown). */ |
| #define GIT_HASH_NALGOS (GIT_HASH_SHA256 + 1) |
| |
| /* "sha1", big-endian */ |
| #define GIT_SHA1_FORMAT_ID 0x73686131 |
| |
| /* The length in bytes and in hex digits of an object name (SHA-1 value). */ |
| #define GIT_SHA1_RAWSZ 20 |
| #define GIT_SHA1_HEXSZ (2 * GIT_SHA1_RAWSZ) |
| /* The block size of SHA-1. */ |
| #define GIT_SHA1_BLKSZ 64 |
| |
| /* "s256", big-endian */ |
| #define GIT_SHA256_FORMAT_ID 0x73323536 |
| |
| /* The length in bytes and in hex digits of an object name (SHA-256 value). */ |
| #define GIT_SHA256_RAWSZ 32 |
| #define GIT_SHA256_HEXSZ (2 * GIT_SHA256_RAWSZ) |
| /* The block size of SHA-256. */ |
| #define GIT_SHA256_BLKSZ 64 |
| |
| /* The length in byte and in hex digits of the largest possible hash value. */ |
| #define GIT_MAX_RAWSZ GIT_SHA256_RAWSZ |
| #define GIT_MAX_HEXSZ GIT_SHA256_HEXSZ |
| /* The largest possible block size for any supported hash. */ |
| #define GIT_MAX_BLKSZ GIT_SHA256_BLKSZ |
| |
| struct object_id { |
| unsigned char hash[GIT_MAX_RAWSZ]; |
| int algo; /* XXX requires 4-byte alignment */ |
| }; |
| |
| #define GET_OID_QUIETLY 01 |
| #define GET_OID_COMMIT 02 |
| #define GET_OID_COMMITTISH 04 |
| #define GET_OID_TREE 010 |
| #define GET_OID_TREEISH 020 |
| #define GET_OID_BLOB 040 |
| #define GET_OID_FOLLOW_SYMLINKS 0100 |
| #define GET_OID_RECORD_PATH 0200 |
| #define GET_OID_ONLY_TO_DIE 04000 |
| #define GET_OID_REQUIRE_PATH 010000 |
| #define GET_OID_HASH_ANY 020000 |
| |
| #define GET_OID_DISAMBIGUATORS \ |
| (GET_OID_COMMIT | GET_OID_COMMITTISH | \ |
| GET_OID_TREE | GET_OID_TREEISH | \ |
| GET_OID_BLOB) |
| |
| enum get_oid_result { |
| FOUND = 0, |
| MISSING_OBJECT = -1, /* The requested object is missing */ |
| SHORT_NAME_AMBIGUOUS = -2, |
| /* The following only apply when symlinks are followed */ |
| DANGLING_SYMLINK = -4, /* |
| * The initial symlink is there, but |
| * (transitively) points to a missing |
| * in-tree file |
| */ |
| SYMLINK_LOOP = -5, |
| NOT_DIR = -6, /* |
| * Somewhere along the symlink chain, a path is |
| * requested which contains a file as a |
| * non-final element. |
| */ |
| }; |
| |
| #ifdef USE_THE_REPOSITORY_VARIABLE |
| # include "repository.h" |
| # define the_hash_algo the_repository->hash_algo |
| #endif |
| |
| /* A suitably aligned type for stack allocations of hash contexts. */ |
| union git_hash_ctx { |
| git_SHA_CTX sha1; |
| git_SHA_CTX_unsafe sha1_unsafe; |
| |
| git_SHA256_CTX sha256; |
| }; |
| typedef union git_hash_ctx git_hash_ctx; |
| |
| typedef void (*git_hash_init_fn)(git_hash_ctx *ctx); |
| typedef void (*git_hash_clone_fn)(git_hash_ctx *dst, const git_hash_ctx *src); |
| typedef void (*git_hash_update_fn)(git_hash_ctx *ctx, const void *in, size_t len); |
| typedef void (*git_hash_final_fn)(unsigned char *hash, git_hash_ctx *ctx); |
| typedef void (*git_hash_final_oid_fn)(struct object_id *oid, git_hash_ctx *ctx); |
| |
| struct git_hash_algo { |
| /* |
| * The name of the algorithm, as appears in the config file and in |
| * messages. |
| */ |
| const char *name; |
| |
| /* A four-byte version identifier, used in pack indices. */ |
| uint32_t format_id; |
| |
| /* The length of the hash in binary. */ |
| size_t rawsz; |
| |
| /* The length of the hash in hex characters. */ |
| size_t hexsz; |
| |
| /* The block size of the hash. */ |
| size_t blksz; |
| |
| /* The hash initialization function. */ |
| git_hash_init_fn init_fn; |
| |
| /* The hash context cloning function. */ |
| git_hash_clone_fn clone_fn; |
| |
| /* The hash update function. */ |
| git_hash_update_fn update_fn; |
| |
| /* The hash finalization function. */ |
| git_hash_final_fn final_fn; |
| |
| /* The hash finalization function for object IDs. */ |
| git_hash_final_oid_fn final_oid_fn; |
| |
| /* The non-cryptographic hash initialization function. */ |
| git_hash_init_fn unsafe_init_fn; |
| |
| /* The non-cryptographic hash context cloning function. */ |
| git_hash_clone_fn unsafe_clone_fn; |
| |
| /* The non-cryptographic hash update function. */ |
| git_hash_update_fn unsafe_update_fn; |
| |
| /* The non-cryptographic hash finalization function. */ |
| git_hash_final_fn unsafe_final_fn; |
| |
| /* The non-cryptographic hash finalization function. */ |
| git_hash_final_oid_fn unsafe_final_oid_fn; |
| |
| /* The OID of the empty tree. */ |
| const struct object_id *empty_tree; |
| |
| /* The OID of the empty blob. */ |
| const struct object_id *empty_blob; |
| |
| /* The all-zeros OID. */ |
| const struct object_id *null_oid; |
| }; |
| extern const struct git_hash_algo hash_algos[GIT_HASH_NALGOS]; |
| |
| /* |
| * Return a GIT_HASH_* constant based on the name. Returns GIT_HASH_UNKNOWN if |
| * the name doesn't match a known algorithm. |
| */ |
| int hash_algo_by_name(const char *name); |
| /* Identical, except based on the format ID. */ |
| int hash_algo_by_id(uint32_t format_id); |
| /* Identical, except based on the length. */ |
| int hash_algo_by_length(int len); |
| /* Identical, except for a pointer to struct git_hash_algo. */ |
| static inline int hash_algo_by_ptr(const struct git_hash_algo *p) |
| { |
| return p - hash_algos; |
| } |
| |
| const struct object_id *null_oid(void); |
| |
| static inline int hashcmp(const unsigned char *sha1, const unsigned char *sha2, const struct git_hash_algo *algop) |
| { |
| /* |
| * Teach the compiler that there are only two possibilities of hash size |
| * here, so that it can optimize for this case as much as possible. |
| */ |
| if (algop->rawsz == GIT_MAX_RAWSZ) |
| return memcmp(sha1, sha2, GIT_MAX_RAWSZ); |
| return memcmp(sha1, sha2, GIT_SHA1_RAWSZ); |
| } |
| |
| static inline int hasheq(const unsigned char *sha1, const unsigned char *sha2, const struct git_hash_algo *algop) |
| { |
| /* |
| * We write this here instead of deferring to hashcmp so that the |
| * compiler can properly inline it and avoid calling memcmp. |
| */ |
| if (algop->rawsz == GIT_MAX_RAWSZ) |
| return !memcmp(sha1, sha2, GIT_MAX_RAWSZ); |
| return !memcmp(sha1, sha2, GIT_SHA1_RAWSZ); |
| } |
| |
| static inline void hashcpy(unsigned char *sha_dst, const unsigned char *sha_src, |
| const struct git_hash_algo *algop) |
| { |
| memcpy(sha_dst, sha_src, algop->rawsz); |
| } |
| |
| static inline void hashclr(unsigned char *hash, const struct git_hash_algo *algop) |
| { |
| memset(hash, 0, algop->rawsz); |
| } |
| |
| static inline int oidcmp(const struct object_id *oid1, const struct object_id *oid2) |
| { |
| return memcmp(oid1->hash, oid2->hash, GIT_MAX_RAWSZ); |
| } |
| |
| static inline int oideq(const struct object_id *oid1, const struct object_id *oid2) |
| { |
| return !memcmp(oid1->hash, oid2->hash, GIT_MAX_RAWSZ); |
| } |
| |
| static inline void oidcpy(struct object_id *dst, const struct object_id *src) |
| { |
| memcpy(dst->hash, src->hash, GIT_MAX_RAWSZ); |
| dst->algo = src->algo; |
| } |
| |
| static inline void oidread(struct object_id *oid, const unsigned char *hash, |
| const struct git_hash_algo *algop) |
| { |
| memcpy(oid->hash, hash, algop->rawsz); |
| if (algop->rawsz < GIT_MAX_RAWSZ) |
| memset(oid->hash + algop->rawsz, 0, GIT_MAX_RAWSZ - algop->rawsz); |
| oid->algo = hash_algo_by_ptr(algop); |
| } |
| |
| static inline void oidclr(struct object_id *oid, |
| const struct git_hash_algo *algop) |
| { |
| memset(oid->hash, 0, GIT_MAX_RAWSZ); |
| oid->algo = hash_algo_by_ptr(algop); |
| } |
| |
| static inline struct object_id *oiddup(const struct object_id *src) |
| { |
| struct object_id *dst = xmalloc(sizeof(struct object_id)); |
| oidcpy(dst, src); |
| return dst; |
| } |
| |
| static inline void oid_set_algo(struct object_id *oid, const struct git_hash_algo *algop) |
| { |
| oid->algo = hash_algo_by_ptr(algop); |
| } |
| |
| /* |
| * Converts a cryptographic hash (e.g. SHA-1) into an int-sized hash code |
| * for use in hash tables. Cryptographic hashes are supposed to have |
| * uniform distribution, so in contrast to `memhash()`, this just copies |
| * the first `sizeof(int)` bytes without shuffling any bits. Note that |
| * the results will be different on big-endian and little-endian |
| * platforms, so they should not be stored or transferred over the net. |
| */ |
| static inline unsigned int oidhash(const struct object_id *oid) |
| { |
| /* |
| * Equivalent to 'return *(unsigned int *)oid->hash;', but safe on |
| * platforms that don't support unaligned reads. |
| */ |
| unsigned int hash; |
| memcpy(&hash, oid->hash, sizeof(hash)); |
| return hash; |
| } |
| |
| static inline int is_null_oid(const struct object_id *oid) |
| { |
| static const unsigned char null_hash[GIT_MAX_RAWSZ]; |
| return !memcmp(oid->hash, null_hash, GIT_MAX_RAWSZ); |
| } |
| |
| const char *empty_tree_oid_hex(const struct git_hash_algo *algop); |
| |
| static inline int is_empty_blob_oid(const struct object_id *oid, |
| const struct git_hash_algo *algop) |
| { |
| return oideq(oid, algop->empty_blob); |
| } |
| |
| static inline int is_empty_tree_oid(const struct object_id *oid, |
| const struct git_hash_algo *algop) |
| { |
| return oideq(oid, algop->empty_tree); |
| } |
| |
| #endif |