git/sha1dc_git.c
Jeff King b19f3fe9dd hex: drop sha1_to_hex()
There's only a single caller left of sha1_to_hex(), since everybody
that has an object name in "unsigned char[]" now uses hash_to_hex()
instead.

This case is in the sha1dc wrapper, where we print a hex sha1 when
we find a collision. This one will always be sha1, regardless of the
current hash algorithm, so we can't use hash_to_hex() here. In
practice we'd probably not be running sha1 at all if it isn't the
current algorithm, but it's possible we might still occasionally
need to compute a sha1 in a post-sha256 world.

Since sha1_to_hex() is just a wrapper for hash_to_hex_algop(), let's
call that ourselves. There's value in getting rid of the sha1-specific
wrapper to de-clutter the global namespace, and to make sure nobody uses
it (and as with sha1_to_hex_r() in the previous patch, we'll drop the
coccinelle transformations, too).

The sha1_to_hex() function is mentioned in a comment; we can easily
swap that out for oid_to_hex() to give a better example.  Also
update the comment that was left stale when we added "struct
object_id *" as a way to name an object and added functions to
convert it to hex.

The function is also mentioned in some test vectors in t4100, but
that's not runnable code, so there's no point in trying to clean it
up.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-11-13 10:09:10 +09:00

38 lines
889 B
C

#include "cache.h"
#ifdef DC_SHA1_EXTERNAL
/*
* Same as SHA1DCInit, but with default save_hash=0
*/
void git_SHA1DCInit(SHA1_CTX *ctx)
{
SHA1DCInit(ctx);
SHA1DCSetSafeHash(ctx, 0);
}
#endif
/*
* Same as SHA1DCFinal, but convert collision attack case into a verbose die().
*/
void git_SHA1DCFinal(unsigned char hash[20], SHA1_CTX *ctx)
{
if (!SHA1DCFinal(hash, ctx))
return;
die("SHA-1 appears to be part of a collision attack: %s",
hash_to_hex_algop(hash, &hash_algos[GIT_HASH_SHA1]));
}
/*
* Same as SHA1DCUpdate, but adjust types to match git's usual interface.
*/
void git_SHA1DCUpdate(SHA1_CTX *ctx, const void *vdata, unsigned long len)
{
const char *data = vdata;
/* We expect an unsigned long, but sha1dc only takes an int */
while (len > INT_MAX) {
SHA1DCUpdate(ctx, data, INT_MAX);
data += INT_MAX;
len -= INT_MAX;
}
SHA1DCUpdate(ctx, data, len);
}