[PATCH v2 02/20] hash: require hash algorithm in `hasheq()`, `hashcmp()` and `hashclr()`

From: Patrick Steinhardt <ps@pks.im>
Date: Jun 13, 2024, 06:13 UTC
Message-ID: <aa468c3d88eb673343b934d3c8e7fe991d15ba2f.1718259125.git.ps@pks.im>
In-Reply-To: <cover.1718259125.git.ps@pks.im>

Many of our hash functions have two variants, one receiving a `struct git_hash_algo` and one that derives it via `the_repository`. Adapt all of those functions to always require the hash algorithm as input and drop the variants that do not accept one.

As those functions are now independent of `the_repository`, we can move them from "hash.h" to "hash-ll.h".

Signed-off-by: Patrick Steinhardt <ps@pks.im>
---
 builtin/index-pack.c     |  6 +++---
 builtin/pack-redundant.c |  8 +++++---
 builtin/unpack-objects.c |  3 ++-
 commit-graph.c           |  3 ++-
 csum-file.c              |  6 +++---
 hash-ll.h                | 15 +++++++++++++--
 hash-lookup.c            |  3 ++-
 hash.h                   | 24 ++----------------------
 http-walker.c            |  2 +-
 match-trees.c            |  2 +-
 notes.c                  |  2 +-
 pack-bitmap-write.c      |  4 ++--
 pack-bitmap.c            |  3 ++-
 pack-check.c             |  5 +++--
 pack-write.c             |  3 ++-
 packfile.c               |  8 ++++----
 read-cache.c             |  8 ++++----
 17 files changed, 52 insertions(+), 53 deletions(-)

diff --git a/builtin/index-pack.c b/builtin/index-pack.c
index 856428fef9..ea727fba16 100644
--- a/builtin/index-pack.c
+++ b/builtin/index-pack.c
@@ -1204,7 +1204,7 @@ static void parse_pack_objects(unsigned char *hash)
 	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))
+	if (!hasheq(fill(the_hash_algo->rawsz), hash, the_repository->hash_algo))
 		die(_("pack is corrupted (SHA1 mismatch)"));
 	use(the_hash_algo->rawsz);
 
@@ -1307,11 +1307,11 @@ static void conclude_pack(int fix_thin_pack, const char *curr_pack, unsigned cha
 		stop_progress_msg(&progress, msg.buf);
 		strbuf_release(&msg);
 		finalize_hashfile(f, tail_hash, FSYNC_COMPONENT_PACK, 0);
-		hashcpy(read_hash, pack_hash);
+		hashcpy(read_hash, pack_hash, the_repository->hash_algo);
 		fixup_pack_header_footer(output_fd, pack_hash,
 					 curr_pack, nr_objects,
 					 read_hash, consumed_bytes-the_hash_algo->rawsz);
-		if (!hasheq(read_hash, tail_hash))
+		if (!hasheq(read_hash, tail_hash, the_repository->hash_algo))
 			die(_("Unexpected tail checksum for %s "
 			      "(disk corruption?)"), curr_pack);
 	}
diff --git a/builtin/pack-redundant.c b/builtin/pack-redundant.c
index 4c735ba069..103c11b9d3 100644
--- a/builtin/pack-redundant.c
+++ b/builtin/pack-redundant.c
@@ -155,7 +155,7 @@ static inline struct llist_item * llist_sorted_remove(struct llist *list, const
 	l = (hint == NULL) ? list->front : hint;
 	prev = NULL;
 	while (l) {
-		const int cmp = hashcmp(l->oid.hash, oid);
+		const int cmp = hashcmp(l->oid.hash, oid, the_repository->hash_algo);
 		if (cmp > 0) /* not in list, since sorted */
 			return prev;
 		if (!cmp) { /* found */
@@ -258,7 +258,8 @@ static void cmp_two_packs(struct pack_list *p1, struct pack_list *p2)
 	while (p1_off < p1->pack->num_objects * p1_step &&
 	       p2_off < p2->pack->num_objects * p2_step)
 	{
-		const int cmp = hashcmp(p1_base + p1_off, p2_base + p2_off);
+		const int cmp = hashcmp(p1_base + p1_off, p2_base + p2_off,
+					the_repository->hash_algo);
 		/* cmp ~ p1 - p2 */
 		if (cmp == 0) {
 			p1_hint = llist_sorted_remove(p1->unique_objects,
@@ -296,7 +297,8 @@ static size_t sizeof_union(struct packed_git *p1, struct packed_git *p2)
 	while (p1_off < p1->num_objects * p1_step &&
 	       p2_off < p2->num_objects * p2_step)
 	{
-		int cmp = hashcmp(p1_base + p1_off, p2_base + p2_off);
+		int cmp = hashcmp(p1_base + p1_off, p2_base + p2_off,
+				  the_repository->hash_algo);
 		/* cmp ~ p1 - p2 */
 		if (cmp == 0) {
 			ret++;
diff --git a/builtin/unpack-objects.c b/builtin/unpack-objects.c
index f1c85a00ae..0855572c27 100644
--- a/builtin/unpack-objects.c
+++ b/builtin/unpack-objects.c
@@ -674,7 +674,8 @@ int cmd_unpack_objects(int argc, const char **argv, const char *prefix UNUSED)
 		if (fsck_finish(&fsck_options))
 			die(_("fsck error in pack objects"));
 	}
-	if (!hasheq(fill(the_hash_algo->rawsz), oid.hash))
+	if (!hasheq(fill(the_hash_algo->rawsz), oid.hash,
+		    the_repository->hash_algo))
 		die("final sha1 did not match");
 	use(the_hash_algo->rawsz);
 
diff --git a/commit-graph.c b/commit-graph.c
index e5dd3553df..3429156b28 100644
--- a/commit-graph.c
+++ b/commit-graph.c
@@ -565,7 +565,8 @@ static int add_graph_to_chain(struct commit_graph *g,
 
 		if (!cur_g ||
 		    !oideq(&oids[n], &cur_g->oid) ||
-		    !hasheq(oids[n].hash, g->chunk_base_graphs + st_mult(g->hash_len, n))) {
+		    !hasheq(oids[n].hash, g->chunk_base_graphs + st_mult(g->hash_len, n),
+			    the_repository->hash_algo)) {
 			warning(_("commit-graph chain does not match"));
 			return 0;
 		}
diff --git a/csum-file.c b/csum-file.c
index 870748e016..f4be0804b7 100644
--- a/csum-file.c
+++ b/csum-file.c
@@ -68,12 +68,12 @@ int finalize_hashfile(struct hashfile *f, unsigned char *result,
 	hashflush(f);
 
 	if (f->skip_hash)
-		hashclr(f->buffer);
+		hashclr(f->buffer, the_repository->hash_algo);
 	else
 		the_hash_algo->final_fn(f->buffer, &f->ctx);
 
 	if (result)
-		hashcpy(result, f->buffer);
+		hashcpy(result, f->buffer, the_repository->hash_algo);
 	if (flags & CSUM_HASH_IN_STREAM)
 		flush(f, f->buffer, the_hash_algo->rawsz);
 	if (flags & CSUM_FSYNC)
@@ -237,5 +237,5 @@ int hashfile_checksum_valid(const unsigned char *data, size_t total_len)
 	the_hash_algo->update_fn(&ctx, data, data_len);
 	the_hash_algo->final_fn(got, &ctx);
 
-	return hasheq(got, data + data_len);
+	return hasheq(got, data + data_len, the_repository->hash_algo);
 }
diff --git a/hash-ll.h b/hash-ll.h
index 2cfde63ae1..fabdd8ecc7 100644
--- a/hash-ll.h
+++ b/hash-ll.h
@@ -245,7 +245,7 @@ static inline int hash_algo_by_ptr(const struct git_hash_algo *p)
 
 const struct object_id *null_oid(void);
 
-static inline int hashcmp_algop(const unsigned char *sha1, const unsigned char *sha2, const struct git_hash_algo *algop)
+static inline int hashcmp(const unsigned char *sha1, const unsigned char *sha2, const struct git_hash_algo *algop)
 {
 	/*
 	 * Teach the compiler that there are only two possibilities of hash size
@@ -256,7 +256,7 @@ static inline int hashcmp_algop(const unsigned char *sha1, const unsigned char *
 	return memcmp(sha1, sha2, GIT_SHA1_RAWSZ);
 }
 
-static inline int hasheq_algop(const unsigned char *sha1, const unsigned char *sha2, const struct git_hash_algo *algop)
+static inline int hasheq(const unsigned char *sha1, const unsigned char *sha2, const struct git_hash_algo *algop)
 {
 	/*
 	 * We write this here instead of deferring to hashcmp so that the
@@ -267,6 +267,17 @@ static inline int hasheq_algop(const unsigned char *sha1, const unsigned char *s
 	return !memcmp(sha1, sha2, GIT_SHA1_RAWSZ);
 }
 
+static inline void hashcpy(unsigned char *sha_dst, const unsigned char *sha_src,
+			   const struct git_hash_algo *algop)
+{
+	memcpy(sha_dst, sha_src, algop->rawsz);
+}
+
+static inline void hashclr(unsigned char *hash, const struct git_hash_algo *algop)
+{
+	memset(hash, 0, algop->rawsz);
+}
+
 static inline void oidcpy(struct object_id *dst, const struct object_id *src)
 {
 	memcpy(dst->hash, src->hash, GIT_MAX_RAWSZ);
diff --git a/hash-lookup.c b/hash-lookup.c
index 9f0f95e2b9..9aa6b82eb7 100644
--- a/hash-lookup.c
+++ b/hash-lookup.c
@@ -112,7 +112,8 @@ int bsearch_hash(const unsigned char *hash, const uint32_t *fanout_nbo,
 
 	while (lo < hi) {
 		unsigned mi = lo + (hi - lo) / 2;
-		int cmp = hashcmp(table + mi * stride, hash);
+		int cmp = hashcmp(table + mi * stride, hash,
+				  the_repository->hash_algo);
 
 		if (!cmp) {
 			if (result)
diff --git a/hash.h b/hash.h
index a1161e1b22..714938e2eb 100644
--- a/hash.h
+++ b/hash.h
@@ -6,11 +6,6 @@
 
 #define the_hash_algo the_repository->hash_algo
 
-static inline int hashcmp(const unsigned char *sha1, const unsigned char *sha2)
-{
-	return hashcmp_algop(sha1, sha2, the_hash_algo);
-}
-
 static inline int oidcmp(const struct object_id *oid1, const struct object_id *oid2)
 {
 	const struct git_hash_algo *algop;
@@ -18,12 +13,7 @@ static inline int oidcmp(const struct object_id *oid1, const struct object_id *o
 		algop = the_hash_algo;
 	else
 		algop = &hash_algos[oid1->algo];
-	return hashcmp_algop(oid1->hash, oid2->hash, algop);
-}
-
-static inline int hasheq(const unsigned char *sha1, const unsigned char *sha2)
-{
-	return hasheq_algop(sha1, sha2, the_hash_algo);
+	return hashcmp(oid1->hash, oid2->hash, algop);
 }
 
 static inline int oideq(const struct object_id *oid1, const struct object_id *oid2)
@@ -33,7 +23,7 @@ static inline int oideq(const struct object_id *oid1, const struct object_id *oi
 		algop = the_hash_algo;
 	else
 		algop = &hash_algos[oid1->algo];
-	return hasheq_algop(oid1->hash, oid2->hash, algop);
+	return hasheq(oid1->hash, oid2->hash, algop);
 }
 
 static inline int is_null_oid(const struct object_id *oid)
@@ -41,11 +31,6 @@ static inline int is_null_oid(const struct object_id *oid)
 	return oideq(oid, null_oid());
 }
 
-static inline void hashcpy(unsigned char *sha_dst, const unsigned char *sha_src)
-{
-	memcpy(sha_dst, sha_src, the_hash_algo->rawsz);
-}
-
 /* Like oidcpy() but zero-pads the unused bytes in dst's hash array. */
 static inline void oidcpy_with_padding(struct object_id *dst,
 				       const struct object_id *src)
@@ -62,11 +47,6 @@ static inline void oidcpy_with_padding(struct object_id *dst,
 	dst->algo = src->algo;
 }
 
-static inline void hashclr(unsigned char *hash)
-{
-	memset(hash, 0, the_hash_algo->rawsz);
-}
-
 static inline void oidclr(struct object_id *oid)
 {
 	memset(oid->hash, 0, GIT_MAX_RAWSZ);
diff --git a/http-walker.c b/http-walker.c
index b395ef1327..cf7f8c82bc 100644
--- a/http-walker.c
+++ b/http-walker.c
@@ -485,7 +485,7 @@ static int fetch_object(struct walker *walker, unsigned char *hash)
 
 	list_for_each(pos, head) {
 		obj_req = list_entry(pos, struct object_request, node);
-		if (hasheq(obj_req->oid.hash, hash))
+		if (hasheq(obj_req->oid.hash, hash, the_repository->hash_algo))
 			break;
 	}
 	if (!obj_req)
diff --git a/match-trees.c b/match-trees.c
index 3412b6a140..849b391d3d 100644
--- a/match-trees.c
+++ b/match-trees.c
@@ -237,7 +237,7 @@ static int splice_tree(const struct object_id *oid1, const char *prefix,
 	} else {
 		rewrite_with = oid2;
 	}
-	hashcpy(rewrite_here, rewrite_with->hash);
+	hashcpy(rewrite_here, rewrite_with->hash, the_repository->hash_algo);
 	status = write_object_file(buf, sz, OBJ_TREE, result);
 	free(buf);
 	return status;
diff --git a/notes.c b/notes.c
index 53ca25c814..5296fd863f 100644
--- a/notes.c
+++ b/notes.c
@@ -149,7 +149,7 @@ static struct leaf_node *note_tree_find(struct notes_tree *t,
 	void **p = note_tree_search(t, &tree, &n, key_sha1);
 	if (GET_PTR_TYPE(*p) == PTR_TYPE_NOTE) {
 		struct leaf_node *l = (struct leaf_node *) CLR_PTR_TYPE(*p);
-		if (hasheq(key_sha1, l->key_oid.hash))
+		if (hasheq(key_sha1, l->key_oid.hash, the_repository->hash_algo))
 			return l;
 	}
 	return NULL;
diff --git a/pack-bitmap-write.c b/pack-bitmap-write.c
index 6cae670412..59d2e3a387 100644
--- a/pack-bitmap-write.c
+++ b/pack-bitmap-write.c
@@ -790,7 +790,7 @@ static void write_hash_cache(struct hashfile *f,
 void bitmap_writer_set_checksum(struct bitmap_writer *writer,
 				const unsigned char *sha1)
 {
-	hashcpy(writer->pack_checksum, sha1);
+	hashcpy(writer->pack_checksum, sha1, the_repository->hash_algo);
 }
 
 void bitmap_writer_finish(struct bitmap_writer *writer,
@@ -816,7 +816,7 @@ void bitmap_writer_finish(struct bitmap_writer *writer,
 	header.version = htons(default_version);
 	header.options = htons(flags | options);
 	header.entry_count = htonl(writer->selected_nr);
-	hashcpy(header.checksum, writer->pack_checksum);
+	hashcpy(header.checksum, writer->pack_checksum, the_repository->hash_algo);
 
 	hashwrite(f, &header, sizeof(header) - GIT_MAX_RAWSZ + the_hash_algo->rawsz);
 	dump_bitmap(f, writer->commits);
diff --git a/pack-bitmap.c b/pack-bitmap.c
index fe8e8a51d3..184d28f05c 100644
--- a/pack-bitmap.c
+++ b/pack-bitmap.c
@@ -367,7 +367,8 @@ static int open_midx_bitmap_1(struct bitmap_index *bitmap_git,
 	if (load_bitmap_header(bitmap_git) < 0)
 		goto cleanup;
 
-	if (!hasheq(get_midx_checksum(bitmap_git->midx), bitmap_git->checksum)) {
+	if (!hasheq(get_midx_checksum(bitmap_git->midx), bitmap_git->checksum,
+		    the_repository->hash_algo)) {
 		error(_("checksum doesn't match in MIDX and bitmap"));
 		goto cleanup;
 	}
diff --git a/pack-check.c b/pack-check.c
index 25104d5b14..288f5a3479 100644
--- a/pack-check.c
+++ b/pack-check.c
@@ -78,10 +78,11 @@ static int verify_packfile(struct repository *r,
 	} while (offset < pack_sig_ofs);
 	r->hash_algo->final_fn(hash, &ctx);
 	pack_sig = use_pack(p, w_curs, pack_sig_ofs, NULL);
-	if (!hasheq(hash, pack_sig))
+	if (!hasheq(hash, pack_sig, r->hash_algo))
 		err = error("%s pack checksum mismatch",
 			    p->pack_name);
-	if (!hasheq(index_base + index_size - r->hash_algo->hexsz, pack_sig))
+	if (!hasheq(index_base + index_size - r->hash_algo->hexsz, pack_sig,
+		    r->hash_algo))
 		err = error("%s pack checksum does not match its index",
 			    p->pack_name);
 	unuse_pack(w_curs);
diff --git a/pack-write.c b/pack-write.c
index 80ecfa544c..eef625fa5b 100644
--- a/pack-write.c
+++ b/pack-write.c
@@ -428,7 +428,8 @@ void fixup_pack_header_footer(int pack_fd,
 		if (partial_pack_offset == 0) {
 			unsigned char hash[GIT_MAX_RAWSZ];
 			the_hash_algo->final_fn(hash, &old_hash_ctx);
-			if (!hasheq(hash, partial_pack_hash))
+			if (!hasheq(hash, partial_pack_hash,
+				    the_repository->hash_algo))
 				die("Unexpected checksum for %s "
 				    "(disk corruption?)", pack_name);
 			/*
diff --git a/packfile.c b/packfile.c
index d4df7fdeea..9156e9122c 100644
--- a/packfile.c
+++ b/packfile.c
@@ -242,7 +242,7 @@ struct packed_git *parse_pack_index(unsigned char *sha1, const char *idx_path)
 	struct packed_git *p = alloc_packed_git(alloc);
 
 	memcpy(p->pack_name, path, alloc); /* includes NUL */
-	hashcpy(p->hash, sha1);
+	hashcpy(p->hash, sha1, the_repository->hash_algo);
 	if (check_packed_git_idx(idx_path, p)) {
 		free(p);
 		return NULL;
@@ -596,7 +596,7 @@ static int open_packed_git_1(struct packed_git *p)
 	if (read_result != hashsz)
 		return error("packfile %s signature is unavailable", p->pack_name);
 	idx_hash = ((unsigned char *)p->index_data) + p->index_size - hashsz * 2;
-	if (!hasheq(hash, idx_hash))
+	if (!hasheq(hash, idx_hash, the_repository->hash_algo))
 		return error("packfile %s does not match index", p->pack_name);
 	return 0;
 }
@@ -751,7 +751,7 @@ struct packed_git *add_packed_git(const char *path, size_t path_len, int local)
 	p->mtime = st.st_mtime;
 	if (path_len < the_hash_algo->hexsz ||
 	    get_hash_hex(path + path_len - the_hash_algo->hexsz, p->hash))
-		hashclr(p->hash);
+		hashclr(p->hash, the_repository->hash_algo);
 	return p;
 }
 
@@ -1971,7 +1971,7 @@ off_t find_pack_entry_one(const unsigned char *sha1,
 			return 0;
 	}
 
-	hashcpy(oid.hash, sha1);
+	hashcpy(oid.hash, sha1, the_repository->hash_algo);
 	if (bsearch_pack(&oid, p, &result))
 		return nth_packed_object_offset(p, result);
 	return 0;
diff --git a/read-cache.c b/read-cache.c
index 10e002ce6d..2642ac9558 100644
--- a/read-cache.c
+++ b/read-cache.c
@@ -1735,7 +1735,7 @@ static int verify_hdr(const struct cache_header *hdr, unsigned long size)
 	the_hash_algo->init_fn(&c);
 	the_hash_algo->update_fn(&c, hdr, size - the_hash_algo->rawsz);
 	the_hash_algo->final_fn(hash, &c);
-	if (!hasheq(hash, start))
+	if (!hasheq(hash, start, the_repository->hash_algo))
 		return error(_("bad index file sha1 signature"));
 	return 0;
 }
@@ -2641,7 +2641,7 @@ static void copy_cache_entry_to_ondisk(struct ondisk_cache_entry *ondisk,
 	ondisk->uid  = htonl(ce->ce_stat_data.sd_uid);
 	ondisk->gid  = htonl(ce->ce_stat_data.sd_gid);
 	ondisk->size = htonl(ce->ce_stat_data.sd_size);
-	hashcpy(ondisk->data, ce->oid.hash);
+	hashcpy(ondisk->data, ce->oid.hash, the_repository->hash_algo);
 
 	flags = ce->ce_flags & ~CE_NAMEMASK;
 	flags |= (ce_namelen(ce) >= CE_NAMEMASK ? CE_NAMEMASK : ce_namelen(ce));
@@ -2730,7 +2730,7 @@ static int verify_index_from(const struct index_state *istate, const char *path)
 	if (n != the_hash_algo->rawsz)
 		goto out;
 
-	if (!hasheq(istate->oid.hash, hash))
+	if (!hasheq(istate->oid.hash, hash, the_repository->hash_algo))
 		goto out;
 
 	close(fd);
@@ -3603,7 +3603,7 @@ static size_t read_eoie_extension(const char *mmap, size_t mmap_size)
 		src_offset += extsize;
 	}
 	the_hash_algo->final_fn(hash, &c);
-	if (!hasheq(hash, (const unsigned char *)index))
+	if (!hasheq(hash, (const unsigned char *)index, the_repository->hash_algo))
 		return 0;
 
 	/* Validate that the extension offsets returned us back to the eoie extension. */

-- 
2.45.2.457.g8d94cfb545.dirty