[git commit master 1/1] Improve unzip's handling of stream ZIP files
Denys Vlasenko
vda.linux at googlemail.com
Fri Jun 18 11:32:39 UTC 2010
commit: http://git.busybox.net/busybox/commit/?id=b76f18d331f865225f1702794e66e87818584f99
branch: http://git.busybox.net/busybox/commit/?id=refs/heads/master
Search harder for the ZIP magic numbers at the end of a file by checking
16 KiB from the end instead of just 1 KiB. ZIP files with long comments
(such as certain cryptographically signed files) or those sitting in a
wrapper could have more than 1 KiB of data after the magic numbers, so
they couldn't be read.
Signed-off-by: Dan Fandrich <dan at coneharvesters.com>
Signed-off-by: Denys Vlasenko <vda.linux at googlemail.com>
---
archival/unzip.c | 13 +++++++++----
1 files changed, 9 insertions(+), 4 deletions(-)
diff --git a/archival/unzip.c b/archival/unzip.c
index 1d3291a..84081c0 100644
--- a/archival/unzip.c
+++ b/archival/unzip.c
@@ -150,23 +150,26 @@ enum { zip_fd = 3 };
#if ENABLE_DESKTOP
+
+#define PEEK_FROM_END 16384
+
/* NB: does not preserve file position! */
static uint32_t find_cdf_offset(void)
{
- unsigned char buf[1024];
cde_header_t cde_header;
unsigned char *p;
off_t end;
+ unsigned char *buf = xzalloc(PEEK_FROM_END);
end = xlseek(zip_fd, 0, SEEK_END);
- end -= 1024;
+ end -= PEEK_FROM_END;
if (end < 0)
end = 0;
xlseek(zip_fd, end, SEEK_SET);
- full_read(zip_fd, buf, 1024);
+ full_read(zip_fd, buf, PEEK_FROM_END);
p = buf;
- while (p <= buf + 1024 - CDE_HEADER_LEN - 4) {
+ while (p <= buf + PEEK_FROM_END - CDE_HEADER_LEN - 4) {
if (*p != 'P') {
p++;
continue;
@@ -180,8 +183,10 @@ static uint32_t find_cdf_offset(void)
/* we found CDE! */
memcpy(cde_header.raw, p + 1, CDE_HEADER_LEN);
FIX_ENDIANNESS_CDE(cde_header);
+ free(buf);
return cde_header.formatted.cdf_offset;
}
+ //free(buf);
bb_error_msg_and_die("can't find file table");
};
--
1.7.1
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