1#ifndef HASH_H 2#define HASH_H 3 4#include "git-compat-util.h" 5 6#if defined(SHA1_PPC) 7#include "ppc/sha1.h" 8#elif defined(SHA1_APPLE) 9#include <CommonCrypto/CommonDigest.h> 10#elif defined(SHA1_OPENSSL) 11#include <openssl/sha.h> 12#elif defined(SHA1_DC) 13#include "sha1dc_git.h" 14#else /* SHA1_BLK */ 15#include "block-sha1/sha1.h" 16#endif 17 18/* 19 * Note that these constants are suitable for indexing the hash_algos array and 20 * comparing against each other, but are otherwise arbitrary, so they should not 21 * be exposed to the user or serialized to disk. To know whether a 22 * git_hash_algo struct points to some usable hash function, test the format_id 23 * field for being non-zero. Use the name field for user-visible situations and 24 * the format_id field for fixed-length fields on disk. 25 */ 26/* An unknown hash function. */ 27#define GIT_HASH_UNKNOWN 0 28/* SHA-1 */ 29#define GIT_HASH_SHA1 1 30/* Number of algorithms supported (including unknown). */ 31#define GIT_HASH_NALGOS (GIT_HASH_SHA1 + 1) 32 33typedef void (*git_hash_init_fn)(void *ctx); 34typedef void (*git_hash_update_fn)(void *ctx, const void *in, size_t len); 35typedef void (*git_hash_final_fn)(unsigned char *hash, void *ctx); 36 37struct git_hash_algo { 38 /* 39 * The name of the algorithm, as appears in the config file and in 40 * messages. 41 */ 42 const char *name; 43 44 /* A four-byte version identifier, used in pack indices. */ 45 uint32_t format_id; 46 47 /* The size of a hash context (e.g. git_SHA_CTX). */ 48 size_t ctxsz; 49 50 /* The length of the hash in binary. */ 51 size_t rawsz; 52 53 /* The length of the hash in hex characters. */ 54 size_t hexsz; 55 56 /* The hash initialization function. */ 57 git_hash_init_fn init_fn; 58 59 /* The hash update function. */ 60 git_hash_update_fn update_fn; 61 62 /* The hash finalization function. */ 63 git_hash_final_fn final_fn; 64 65 /* The OID of the empty tree. */ 66 const struct object_id *empty_tree; 67 68 /* The OID of the empty blob. */ 69 const struct object_id *empty_blob; 70}; 71extern const struct git_hash_algo hash_algos[GIT_HASH_NALGOS]; 72 73#endif