13eeedb5d1
SHA-1 is weak and we need to transition to a new hash function. For some time, we have referred to this new function as NewHash. Recently, we decided to pick SHA-256 as NewHash. The reasons behind the choice of SHA-256 are outlined in the thread starting at [1] and in the commit history for the hash function transition document. Add a basic implementation of SHA-256 based off libtomcrypt, which is in the public domain. Optimize it and restructure it to meet our coding standards. Pull in the update and final functions from the SHA-1 block implementation, as we know these function correctly with all compilers. This implementation is slower than SHA-1, but more performant implementations will be introduced in future commits. Wire up SHA-256 in the list of hash algorithms, and add a test that the algorithm works correctly. Note that with this patch, it is still not possible to switch to using SHA-256 in Git. Additional patches are needed to prepare the code to handle a larger hash algorithm and further test fixes are needed. [1] https://public-inbox.org/git/20180609224913.GC38834@genre.crustytoothpaste.net/ Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
25 lines
633 B
C
25 lines
633 B
C
#ifndef SHA256_BLOCK_SHA256_H
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#define SHA256_BLOCK_SHA256_H
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#define blk_SHA256_BLKSIZE 64
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struct blk_SHA256_CTX {
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uint32_t state[8];
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uint64_t size;
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uint32_t offset;
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uint8_t buf[blk_SHA256_BLKSIZE];
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};
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typedef struct blk_SHA256_CTX blk_SHA256_CTX;
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void blk_SHA256_Init(blk_SHA256_CTX *ctx);
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void blk_SHA256_Update(blk_SHA256_CTX *ctx, const void *data, size_t len);
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void blk_SHA256_Final(unsigned char *digest, blk_SHA256_CTX *ctx);
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#define platform_SHA256_CTX blk_SHA256_CTX
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#define platform_SHA256_Init blk_SHA256_Init
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#define platform_SHA256_Update blk_SHA256_Update
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#define platform_SHA256_Final blk_SHA256_Final
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#endif
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