git/block-sha1/sha1.h

/*
 * Based on the Mozilla SHA1 (see mozilla-sha1/sha1.h),
 * optimized to do word accesses rather than byte accesses,
 * and to avoid unnecessary copies into the context array.
 */

typedef struct {
	unsigned int H[5];
	unsigned int W[16];
	unsigned long long size;
} blk_SHA_CTX;

void blk_SHA1_Init(blk_SHA_CTX *ctx);
void blk_SHA1_Update(blk_SHA_CTX *ctx, const void *dataIn, unsigned long len);
void blk_SHA1_Final(unsigned char hashout[20], blk_SHA_CTX *ctx);

#define git_SHA_CTX	blk_SHA_CTX
#define git_SHA1_Init	blk_SHA1_Init
#define git_SHA1_Update	blk_SHA1_Update
#define git_SHA1_Final	blk_SHA1_Final