From 768e30ea27c58aa69893e10b96ba5ba5680dc3cf Mon Sep 17 00:00:00 2001 From: "brian m. carlson" Date: Sat, 22 Feb 2020 20:17:27 +0000 Subject: 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 Signed-off-by: Junio C Hamano --- hash.h | 21 +++++++++++++++++++++ 1 file changed, 21 insertions(+) (limited to 'hash.h') diff --git a/hash.h b/hash.h index 52a4f1a3f4..e0f3f16b06 100644 --- a/hash.h +++ b/hash.h @@ -16,6 +16,7 @@ #endif #if defined(SHA256_GCRYPT) +#define SHA256_NEEDS_CLONE_HELPER #include "sha256/gcrypt.h" #elif defined(SHA256_OPENSSL) #include @@ -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; -- cgit v1.2.3