diff options
| -rw-r--r-- | index-pack.c | 21 | ||||
| -rwxr-xr-x | t/t5300-pack-object.sh | 10 |
2 files changed, 27 insertions, 4 deletions
diff --git a/index-pack.c b/index-pack.c index b405864be..4effb2da6 100644 --- a/index-pack.c +++ b/index-pack.c @@ -345,7 +345,8 @@ static int find_delta_children(const union delta_base *base, } static void sha1_object(const void *data, unsigned long size, - enum object_type type, unsigned char *sha1) + enum object_type type, unsigned char *sha1, + int test_for_collision) { SHA_CTX ctx; char header[50]; @@ -367,6 +368,18 @@ static void sha1_object(const void *data, unsigned long size, SHA1_Update(&ctx, header, header_size); SHA1_Update(&ctx, data, size); SHA1_Final(sha1, &ctx); + + if (test_for_collision && has_sha1_file(sha1)) { + void *has_data; + enum object_type has_type; + unsigned long has_size; + has_data = read_sha1_file(sha1, &has_type, &has_size); + if (!has_data) + die("cannot read existing object %s", sha1_to_hex(sha1)); + if (size != has_size || type != has_type || + memcmp(data, has_data, size) != 0) + die("SHA1 COLLISION FOUND WITH %s !", sha1_to_hex(sha1)); + } } static void resolve_delta(struct object_entry *delta_obj, void *base_data, @@ -387,7 +400,7 @@ static void resolve_delta(struct object_entry *delta_obj, void *base_data, free(delta_data); if (!result) bad_object(delta_obj->offset, "failed to apply delta"); - sha1_object(result, result_size, type, delta_obj->sha1); + sha1_object(result, result_size, type, delta_obj->sha1, 1); nr_resolved_deltas++; hashcpy(delta_base.sha1, delta_obj->sha1); @@ -444,7 +457,7 @@ static void parse_pack_objects(unsigned char *sha1) delta->obj_no = i; delta++; } else - sha1_object(data, obj->size, obj->type, obj->sha1); + sha1_object(data, obj->size, obj->type, obj->sha1, 1); free(data); if (verbose) percent = display_progress(i+1, nr_objects, percent); @@ -565,7 +578,7 @@ static void append_obj_to_pack(void *buf, write_or_die(output_fd, header, n); obj[1].offset = obj[0].offset + n; obj[1].offset += write_compressed(output_fd, buf, size); - sha1_object(buf, size, type, obj->sha1); + sha1_object(buf, size, type, obj->sha1, 0); } static int delta_pos_compare(const void *_a, const void *_b) diff --git a/t/t5300-pack-object.sh b/t/t5300-pack-object.sh index eacb1e92c..35e036a86 100755 --- a/t/t5300-pack-object.sh +++ b/t/t5300-pack-object.sh @@ -255,4 +255,14 @@ test_expect_success \ :' +test_expect_success \ + 'fake a SHA1 hash collision' \ + 'test -f .git/objects/c8/2de19312b6c3695c0c18f70709a6c535682a67 && + cp -f .git/objects/9d/235ed07cd19811a6ceb342de82f190e49c9f68 \ + .git/objects/c8/2de19312b6c3695c0c18f70709a6c535682a67' + +test_expect_failure \ + 'make sure index-pack detects the SHA1 collision' \ + 'git-index-pack -o bad.idx test-3.pack' + test_done |