Re: [PATCH] sanity check in add_packed_git()
Daniel Barkalow <barkalow@iabervon.org> writes:
> I'd like to require it to be a hash, just because that makes it
> prohibitively difficult to make something people will accept as
> pack-05f611b3b8198b262acdf678584d365f8e879aec.pack other than the one from
> the git repository.
How about doing something like this, then?
I haven't tried this with http-fetch but with this I think we can unconditionally assign p->sha1 in add_packed_git().
-- >8 --
Subject: [PATCH] Require packfiles to follow the naming convention.
With this, pack files must be named "pack-[0-9a-f]{40}.pack", with corresponding .idx file, and the hexadecimal part must match the SHA1 checksum git-pack-objects computed when the pack was created originally (i.e. sum over sorted object names of all the contained objects). The core would ignore a valid packfile in $GIT_OBJECT_DIRECTORY/packs that "git-unpack-objects" would expand properly if it does not follow the naming convention.
[jc: this breaks existing test t5300.]
Signed-off-by: Junio C Hamano <junkio@cox.net>
---
sha1_file.c | 38 +++++++++++++++++++++++++++++++++++++-
1 files changed, 37 insertions(+), 1 deletions(-)
4ff64a29401b28cfbd925cf86eed8b8e734ed24b
Show changes to sha1_file.c +37 −1
diff --git a/sha1_file.c b/sha1_file.c
index 6011473..01ac925 100644
--- a/sha1_file.c
+++ b/sha1_file.c
@@ -319,18 +319,33 @@ struct packed_git *packed_git;
static int check_packed_git_idx(const char *path, unsigned long *idx_size_,
void **idx_map_)
{
+ SHA_CTX ctx;
+ unsigned char sha1[20];
+ unsigned char packname[20];
void *idx_map;
unsigned int *index;
unsigned long idx_size;
int nr, i;
- int fd = open(path, O_RDONLY);
+ int fd;
struct stat st;
+
+ fd = open(path, O_RDONLY);
if (fd < 0)
return -1;
if (fstat(fd, &st)) {
close(fd);
return -1;
}
+
+ /* We require "...../pack-XXXX{40}XXXX.idx" now.
+ * 5-byte "pack-", 40-byte hex and 4-byte .idx.
+ */
+ i = strlen(path);
+ if (i < 49 || strcmp(path + i - 4, ".idx") ||
+ strncmp(path + i - 49, "pack-", 5) ||
+ get_sha1_hex(path + i - 44, packname))
+ return error("non index file %s ignored", path);
+
idx_size = st.st_size;
idx_map = mmap(NULL, idx_size, PROT_READ, MAP_PRIVATE, fd, 0);
close(fd);
@@ -362,6 +377,27 @@ static int check_packed_git_idx(const ch
if (idx_size != 4*256 + nr * 24 + 20 + 20)
return error("wrong index file size");
+ /*
+ * File checksum and index name.
+ */
+ SHA1_Init(&ctx);
+ SHA1_Update(&ctx, idx_map, idx_size-20);
+ SHA1_Final(sha1, &ctx);
+
+ if (memcmp(sha1, idx_map + idx_size - 20, 20))
+ return error("index checksum mismatch");
+
+ SHA1_Init(&ctx);
+ for (i = 0; i < nr; i++) {
+ unsigned char *ent = (idx_map + 4*256) + i * 24 + 4;
+ SHA1_Update(&ctx, ent, 20);
+ }
+ SHA1_Final(sha1, &ctx);
+
+ if (memcmp(sha1, packname, 20))
+ return error("pack index name %s does not match contents %s",
+ path, sha1_to_hex(sha1));
+
return 0;
}
--
1.0.GIT
