diff options
author | brian m. carlson <sandals@crustytoothpaste.net> | 2020-02-22 23:17:27 +0300 |
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committer | Junio C Hamano <gitster@pobox.com> | 2020-02-24 20:33:21 +0300 |
commit | 768e30ea27c58aa69893e10b96ba5ba5680dc3cf (patch) | |
tree | eed6e6b8db5bcef9ee99aa7e1fd675da3e6e7e54 /hash.h | |
parent | 207899137dd75916f65bb9988ccf0559760427d6 (diff) |
hash: implement and use a context cloning function
For all of our SHA-1 implementations and most of our SHA-256
implementations, the hash context we use is a real struct. For these
implementations, it's possible to copy a hash context by making a copy
of the struct.
However, for our libgcrypt implementation, our hash context is a
pointer. Consequently, copying it does not lead to an independent hash
context like we intended.
Fortunately, however, libgcrypt provides us with a handy function to
copy hash contexts. Let's add a cloning function to the hash algorithm
API, and use it in the one place we need to make a hash context copy.
With this change, our libgcrypt SHA-256 implementation is fully
functional with all of our other hash implementations.
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Diffstat (limited to 'hash.h')
-rw-r--r-- | hash.h | 21 |
1 files changed, 21 insertions, 0 deletions
@@ -16,6 +16,7 @@ #endif #if defined(SHA256_GCRYPT) +#define SHA256_NEEDS_CLONE_HELPER #include "sha256/gcrypt.h" #elif defined(SHA256_OPENSSL) #include <openssl/sha.h> @@ -54,12 +55,28 @@ #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 +static inline void git_SHA1_Clone(git_SHA_CTX *dst, const git_SHA_CTX *src) +{ + memcpy(dst, src, sizeof(*dst)); +} + +#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 @@ -85,6 +102,7 @@ union git_hash_ctx { 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); @@ -110,6 +128,9 @@ struct git_hash_algo { /* 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; |