git/block-sha1/sha1.h
Taylor Blau 4c61a1d040 sha1: do not redefine platform_SHA_CTX and friends
Our in-tree SHA-1 wrappers all define platform_SHA_CTX and related
macros to point at the opaque "context" type, init, update, and similar
functions for each specific implementation.

In hash.h, we use these platform_ variables to set up the function
pointers for, e.g., the_hash_algo->init_fn(), etc.

But while these header files have a header-specific macro that prevents
them declaring their structs / functions multiple times, they
unconditionally define the platform variables, making it impossible to
load multiple SHA-1 implementations at once.

As a prerequisite for loading a separate SHA-1 implementation for
non-cryptographic uses, only define the platform_ variables if they have
not already been defined.

Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-09-27 11:27:47 -07:00

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C

/*
* SHA1 routine optimized to do word accesses rather than byte accesses,
* and to avoid unnecessary copies into the context array.
*
* This was initially based on the Mozilla SHA1 implementation, although
* none of the original Mozilla code remains.
*/
typedef struct {
unsigned long long size;
unsigned int H[5];
unsigned int W[16];
} blk_SHA_CTX;
void blk_SHA1_Init(blk_SHA_CTX *ctx);
void blk_SHA1_Update(blk_SHA_CTX *ctx, const void *dataIn, size_t len);
void blk_SHA1_Final(unsigned char hashout[20], blk_SHA_CTX *ctx);
#ifndef platform_SHA_CTX
#define platform_SHA_CTX blk_SHA_CTX
#define platform_SHA1_Init blk_SHA1_Init
#define platform_SHA1_Update blk_SHA1_Update
#define platform_SHA1_Final blk_SHA1_Final
#endif