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-rw-r--r--sha1_file.c85
1 files changed, 45 insertions, 40 deletions
diff --git a/sha1_file.c b/sha1_file.c
index ce90e20..76f66e6 100644
--- a/sha1_file.c
+++ b/sha1_file.c
@@ -711,17 +711,39 @@ int legacy_loose_object(unsigned char *map)
return 0;
}
-static int unpack_sha1_header(z_stream *stream, unsigned char *map, unsigned long mapsize, void *buffer, unsigned long bufsiz)
+static unsigned long unpack_object_header_gently(const unsigned char *buf, unsigned long len, enum object_type *type, unsigned long *sizep)
{
+ unsigned shift;
unsigned char c;
- unsigned int bits;
unsigned long size;
- static const char *typename[8] = {
- NULL, /* OBJ_EXT */
- "commit", "tree", "blob", "tag",
- NULL, NULL, NULL
+ unsigned long used = 0;
+
+ c = buf[used++];
+ *type = (c >> 4) & 7;
+ size = c & 15;
+ shift = 4;
+ while (c & 0x80) {
+ if (len <= used)
+ return 0;
+ if (sizeof(long) * 8 <= shift)
+ return 0;
+ c = buf[used++];
+ size += (c & 0x7f) << shift;
+ shift += 7;
+ }
+ *sizep = size;
+ return used;
+}
+
+static int unpack_sha1_header(z_stream *stream, unsigned char *map, unsigned long mapsize, void *buffer, unsigned long bufsiz)
+{
+ unsigned long size, used;
+ static const char valid_loose_object_type[8] = {
+ 0, /* OBJ_EXT */
+ 1, 1, 1, 1, /* "commit", "tree", "blob", "tag" */
+ 0, /* "delta" and others are invalid in a loose object */
};
- const char *type;
+ enum object_type type;
/* Get the data stream */
memset(stream, 0, sizeof(*stream));
@@ -735,22 +757,11 @@ static int unpack_sha1_header(z_stream *stream, unsigned char *map, unsigned lon
return inflate(stream, 0);
}
- c = *map++;
- mapsize--;
- type = typename[(c >> 4) & 7];
- if (!type)
+ used = unpack_object_header_gently(map, mapsize, &type, &size);
+ if (!used || !valid_loose_object_type[type])
return -1;
-
- bits = 4;
- size = c & 0xf;
- while ((c & 0x80)) {
- if (bits >= 8*sizeof(long))
- return -1;
- c = *map++;
- size += (c & 0x7f) << bits;
- bits += 7;
- mapsize--;
- }
+ map += used;
+ mapsize -= used;
/* Set up the stream for the rest.. */
stream->next_in = map;
@@ -758,7 +769,8 @@ static int unpack_sha1_header(z_stream *stream, unsigned char *map, unsigned lon
inflateInit(stream);
/* And generate the fake traditional header */
- stream->total_out = 1 + snprintf(buffer, bufsiz, "%s %lu", type, size);
+ stream->total_out = 1 + snprintf(buffer, bufsiz, "%s %lu",
+ type_names[type], size);
return 0;
}
@@ -916,25 +928,18 @@ static int packed_delta_info(unsigned char *base_sha1,
static unsigned long unpack_object_header(struct packed_git *p, unsigned long offset,
enum object_type *type, unsigned long *sizep)
{
- unsigned shift;
- unsigned char c;
- unsigned long size;
+ unsigned long used;
- if (offset >= p->pack_size)
+ if (p->pack_size <= offset)
die("object offset outside of pack file");
- c = *((unsigned char *)p->pack_base + offset++);
- *type = (c >> 4) & 7;
- size = c & 15;
- shift = 4;
- while (c & 0x80) {
- if (offset >= p->pack_size)
- die("object offset outside of pack file");
- c = *((unsigned char *)p->pack_base + offset++);
- size += (c & 0x7f) << shift;
- shift += 7;
- }
- *sizep = size;
- return offset;
+
+ used = unpack_object_header_gently((unsigned char *)p->pack_base +
+ offset,
+ p->pack_size - offset, type, sizep);
+ if (!used)
+ die("object offset outside of pack file");
+
+ return offset + used;
}
int check_reuse_pack_delta(struct packed_git *p, unsigned long offset,