@@ -2147,11 +2147,11 @@ static int fetch_and_setup_pack_index(struct packed_git **packs_head,
int http_get_info_packs(const char *base_url, struct packed_git **packs_head)
{
struct http_get_options options = {0};
- int ret = 0, i = 0;
- char *url, *data;
+ int ret = 0;
+ char *url;
+ const char *data;
struct strbuf buf = STRBUF_INIT;
- unsigned char hash[GIT_MAX_RAWSZ];
- const unsigned hexsz = the_hash_algo->hexsz;
+ struct object_id oid;
end_url_with_slash(&buf, base_url);
strbuf_addstr(&buf, "objects/info/packs");
@@ -2163,24 +2163,17 @@ int http_get_info_packs(const char *base_url, struct packed_git **packs_head)
goto cleanup;
data = buf.buf;
- while (i < buf.len) {
- switch (data[i]) {
- case 'P':
- i++;
- if (i + hexsz + 12 <= buf.len &&
- starts_with(data + i, " pack-") &&
- starts_with(data + i + hexsz + 6, ".pack\n")) {
- get_sha1_hex(data + i + 6, hash);
- fetch_and_setup_pack_index(packs_head, hash,
- base_url);
- i += hexsz + 11;
- break;
- }
- default:
- while (i < buf.len && data[i] != '\n')
- i++;
+ while (*data) {
+ if (skip_prefix(data, "P pack-", &data) &&
+ !parse_oid_hex(data, &oid, &data) &&
+ skip_prefix(data, ".pack", &data) &&
+ (*data == '\n' || *data == '\0')) {
+ fetch_and_setup_pack_index(packs_head, oid.hash, base_url);
+ } else {
+ data = strchrnul(data, '\n');
}
- i++;
+ if (*data)
+ data++; /* skip past newline */
}
cleanup:
We can use skip_prefix() and parse_oid_hex() to continuously increment our pointer, rather than dealing with magic numbers. This also fixes a few small shortcomings: - if we see a line with the right prefix, suffix, and length, i.e. matching /P pack-.{40}.pack\n/, we'll interpret the middle part as hex without checking if it could be parsed. This could lead to us looking at uninitialized garbage in the hash array. In practice this means we'll just make a garbage request to the server which will fail, though it's interesting that a malicious server could convince us to leak 40 bytes of uninitialized stack to them. - the current code is picky about seeing a newline at the end of file, but we can easily be more liberal Signed-off-by: Jeff King <peff@peff.net> --- This drops an incorrect claim from the v1 commit message. Sorry, I only remembered to deal with it as I was sending the patch out, so it is not reflected in the range-diff in the cover letter. http.c | 35 ++++++++++++++--------------------- 1 file changed, 14 insertions(+), 21 deletions(-)