Subject: Re: [REGRESSION] Can't clone GitHub repos (fetch-pack error) due to avoiding deprecated OpenSSL SHA-1 routines

From: Eric Wong <[email-masked]>
Date: Fri, 1 Sep 2023 00:57:42 +0000

"brian m. carlson" <[email-masked]> wrote:
> Hopefully this gives someone a good push in the right direction on
> solving the problem.

Thanks.  Here's my WIP which fixes clones on SHA-1 and SHA-256
 <https://80x24.org/sha256test.git> and also t1050-large.sh, but
t1514-rev-parse-push.sh is still broken...

That said, I don't much understand some of the code I'm modifying
and just poking at it until tests pass and valgrind is happy :x

diff --git a/builtin/index-pack.c b/builtin/index-pack.c
index 006ffdc9c5..dda94a9f46 100644
--- a/builtin/index-pack.c
+++ b/builtin/index-pack.c
@@ -1166,6 +1166,7 @@ static void parse_pack_objects(unsigned char *hash)
 	struct ofs_delta_entry *ofs_delta = ofs_deltas;
 	struct object_id ref_delta_oid;
 	struct stat st;
+	git_hash_ctx tmp_ctx;
 
 	if (verbose)
 		progress = start_progress(
@@ -1202,7 +1203,9 @@ static void parse_pack_objects(unsigned char *hash)
 
 	/* Check pack integrity */
 	flush();
-	the_hash_algo->final_fn(hash, &input_ctx);
+	the_hash_algo->init_fn(&tmp_ctx);
+	the_hash_algo->clone_fn(&tmp_ctx, &input_ctx);
+	the_hash_algo->final_fn(hash, &tmp_ctx);
 	if (!hasheq(fill(the_hash_algo->rawsz), hash))
 		die(_("pack is corrupted (SHA1 mismatch)"));
 	use(the_hash_algo->rawsz);
diff --git a/bulk-checkin.c b/bulk-checkin.c
index 73bff3a23d..92b9c8598b 100644
--- a/bulk-checkin.c
+++ b/bulk-checkin.c
@@ -268,6 +268,7 @@ static int deflate_to_pack(struct bulk_checkin_packfile *state,
 					  type, size);
 	the_hash_algo->init_fn(&ctx);
 	the_hash_algo->update_fn(&ctx, obuf, header_len);
+	the_hash_algo->init_fn(&checkpoint.ctx);
 
 	/* Note: idx is non-NULL when we are writing */
 	if ((flags & HASH_WRITE_OBJECT) != 0)
diff --git a/csum-file.c b/csum-file.c
index cd01713244..870748e016 100644
--- a/csum-file.c
+++ b/csum-file.c
@@ -207,7 +207,7 @@ int hashfile_truncate(struct hashfile *f, struct hashfile_checkpoint *checkpoint
 	    lseek(f->fd, offset, SEEK_SET) != offset)
 		return -1;
 	f->total = offset;
-	f->ctx = checkpoint->ctx;
+	the_hash_algo->clone_fn(&f->ctx, &checkpoint->ctx);
 	f->offset = 0; /* hashflush() was called in checkpoint */
 	return 0;
 }