From f9221e2cf5049805d9151b3db6a5eef07b1cc92e Mon Sep 17 00:00:00 2001 From: Taylor Blau Date: Wed, 23 Jun 2021 14:39:07 -0400 Subject: csum-file: introduce checksum_valid() Introduce a new function which checks the validity of a file's trailing checksum. This is similar to hashfd_check(), but different since it is intended to be used by callers who aren't writing the same data (like `git index-pack --verify`), but who instead want to validate the integrity of data that they are reading. Rewrite the first of two callers which could benefit from this new function in pack-check.c. Subsequent callers will be added in the following patches. Helped-by: Jeff King Signed-off-by: Jeff King Signed-off-by: Taylor Blau Signed-off-by: Junio C Hamano --- csum-file.c | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) (limited to 'csum-file.c') diff --git a/csum-file.c b/csum-file.c index 7510950fa3..60f58f662a 100644 --- a/csum-file.c +++ b/csum-file.c @@ -187,3 +187,19 @@ uint32_t crc32_end(struct hashfile *f) f->do_crc = 0; return f->crc32; } + +int hashfile_checksum_valid(const unsigned char *data, size_t total_len) +{ + unsigned char got[GIT_MAX_RAWSZ]; + git_hash_ctx ctx; + size_t data_len = total_len - the_hash_algo->rawsz; + + if (total_len < the_hash_algo->rawsz) + return 0; /* say "too short"? */ + + the_hash_algo->init_fn(&ctx); + the_hash_algo->update_fn(&ctx, data, data_len); + the_hash_algo->final_fn(got, &ctx); + + return hasheq(got, data + data_len); +} -- cgit v1.2.3