tar: fix checksum calculation (signed/unsigned issue)

some archives gave the error: "malformed tar archive"

test file where this occurred:
   http://nl.alpinelinux.org/alpine/v3.1/main/x86_64/apk-tools-static-2.5.0_rc1-r0.apk
This commit is contained in:
Hiltjo Posthuma 2015-05-08 22:01:37 +02:00 committed by sin
parent 29649762b3
commit deb8a16527
1 changed files with 2 additions and 2 deletions

4
tar.c
View File

@ -237,7 +237,7 @@ archive(const char *path)
memset(h->chksum, ' ', sizeof(h->chksum));
for (i = 0, chksum = 0; i < sizeof(*h); i++)
chksum += b[i];
chksum += (unsigned char)b[i];
putoctal(h->chksum, chksum, sizeof(h->chksum));
ewrite(tarfd, b, BLKSIZ);
@ -412,7 +412,7 @@ chktar(struct header *h)
goto bad;
memset(h->chksum, ' ', sizeof(h->chksum));
for (i = 0, s2 = 0; i < sizeof(*h); i++)
s2 += p[i];
s2 += (unsigned char)p[i];
if (s1 != s2)
goto bad;
memcpy(h->chksum, tmp, sizeof(h->chksum));