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author | Taylor Blau <me@ttaylorr.com> | 2021-06-23 14:39:07 -0400 |
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committer | Junio C Hamano <gitster@pobox.com> | 2021-06-28 20:36:17 -0700 |
commit | f9221e2cf5049805d9151b3db6a5eef07b1cc92e (patch) | |
tree | 962e5c2742ae80de7f45353ba5813580caeeaa99 /csum-file.c | |
parent | Git 2.32 (diff) | |
download | tgif-f9221e2cf5049805d9151b3db6a5eef07b1cc92e.tar.xz |
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 <peff@peff.net>
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Diffstat (limited to 'csum-file.c')
-rw-r--r-- | csum-file.c | 16 |
1 files changed, 16 insertions, 0 deletions
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); +} |