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authorPatrick McDermott <patrick.mcdermott@libiquity.com>2023-04-17 13:30:40 (EDT)
committer Patrick McDermott <patrick.mcdermott@libiquity.com>2023-04-17 14:34:36 (EDT)
commit38c8dc91a43cbb8d7d08e92c5149929a12007840 (patch)
treead0e2e55594da8435b2e7eb949162531c779472f /src
parent1aa6cc9fece03a928a17b54e4c56f477d089ca6f (diff)
ustar: Verify header checksums
Diffstat (limited to 'src')
-rw-r--r--src/ustar.c28
1 files changed, 25 insertions, 3 deletions
diff --git a/src/ustar.c b/src/ustar.c
index a4395f4..c183560 100644
--- a/src/ustar.c
+++ b/src/ustar.c
@@ -75,7 +75,11 @@ _opkg_opk_ustar_next(struct opkg_opk_ustar *ustar,
struct _opkg_opk_ustar_header *header)
{
static unsigned char record[OPKG_OPK_USTAR_RECORD_SIZE];
- char *size_end;
+ char *end;
+ uint32_t chksum_got;
+ uint32_t chksum_exp;
+ int i;
+ unsigned char *header_uc;
switch (opkg_opk_gzip_read(ustar->gzip, header)) {
case OPKG_OPK_OK:
@@ -88,13 +92,31 @@ _opkg_opk_ustar_next(struct opkg_opk_ustar *ustar,
if (memcmp(header, record, OPKG_OPK_USTAR_RECORD_SIZE) == 0) {
return OPKG_OPK_END;
}
+
if (memcmp(header->magic, "ustar", strlen("ustar")) != 0) {
return OPKG_OPK_ERROR;
}
- ustar->data_size_remaining = strtol((char *) header->size, &size_end,
+ chksum_got = strtol((char *) header->chksum, &end,
+ OPKG_OPK_USTAR_NUM_BASE_);
+ chksum_exp = 0;
+ if (*end != '\0') {
+ return OPKG_OPK_ERROR;
+ }
+ for (i = 0; i < sizeof(header->chksum); ++i) {
+ header->chksum[i] = ' ';
+ }
+ header_uc = header;
+ for (i = 0; i < OPKG_OPK_USTAR_RECORD_SIZE; ++i) {
+ chksum_exp += header_uc[i];
+ }
+ if (chksum_got != chksum_exp) {
+ return OPKG_OPK_ERROR;
+ }
+
+ ustar->data_size_remaining = strtol((char *) header->size, &end,
OPKG_OPK_USTAR_NUM_BASE_);
- if (*size_end != '\0') {
+ if (*end != '\0') {
return OPKG_OPK_ERROR;
}