adb: make adb mmap/stream parser more united, add ADB_BLOCK_DATAX

Harden the error checking of expected block types and their order.
Add ADB_BLOCK_DATAX as reserved for >1GB blocks.
cute-signatures
Timo Teräs 2021-07-21 16:13:39 +03:00
parent 05364528bb
commit 2f1186aa40
4 changed files with 61 additions and 47 deletions

View File

@ -76,37 +76,45 @@ static int __adb_m_parse(struct adb *db, apk_blob_t data, struct apk_trust *t,
struct adb_verify_ctx vfy = {};
struct adb_block *blk;
struct apk_istream is;
int r = -APKE_ADB_BLOCK;
int trusted = t ? 0 : 1;
int r = 0, trusted = t ? 0 : 1;
uint32_t type, allowed = BIT(ADB_BLOCK_ADB);
adb_foreach_block(blk, data) {
apk_blob_t b = adb_block_blob(blk);
switch (adb_block_type(blk)) {
type = adb_block_type(blk);
if (!(BIT(type) & allowed)) {
r = -APKE_ADB_BLOCK;
break;
}
switch (type) {
case ADB_BLOCK_ADB:
if (!APK_BLOB_IS_NULL(db->adb)) break;
allowed = BIT(ADB_BLOCK_SIG) | BIT(ADB_BLOCK_DATA) | BIT(ADB_BLOCK_DATAX);
db->adb = b;
break;
case ADB_BLOCK_SIG:
if (APK_BLOB_IS_NULL(db->adb)) break;
if (!trusted &&
adb_trust_verify_signature(t, db, &vfy, b) == 0)
trusted = 1;
break;
default:
if (APK_BLOB_IS_NULL(db->adb)) break;
case ADB_BLOCK_DATA:
allowed = BIT(ADB_BLOCK_DATA) | BIT(ADB_BLOCK_DATAX);
if (!trusted) goto err;
break;
case ADB_BLOCK_DATAX:
r = -APKE_ADB_BLOCK;
break;
}
r = cb(db, blk, apk_istream_from_blob(&is, b));
if (r < 0) goto err;
if (r < 0) break;
}
if (IS_ERR(blk)) r = PTR_ERR(blk);
else if (!trusted) r = -APKE_SIGNATURE_UNTRUSTED;
else if (db->adb.ptr) r = 0;
if (r != 0) {
err:
db->adb = APK_BLOB_NULL;
err:
if (r > 0) r = -APKE_ADB_BLOCK;
if (r == 0) {
if (IS_ERR(blk)) r = PTR_ERR(blk);
else if (!trusted) r = -APKE_SIGNATURE_UNTRUSTED;
else if (!db->adb.ptr) r = -APKE_ADB_BLOCK;
}
if (r != 0) db->adb = APK_BLOB_NULL;
return r;
}
@ -147,8 +155,8 @@ static int __adb_m_stream(struct adb *db, struct apk_istream *is, uint32_t expec
struct adb_block blk;
struct apk_segment_istream seg;
void *sig;
int r, block_no = 0;
int trusted = t ? 0 : 1;
int r = 0, trusted = t ? 0 : 1;
uint32_t type, allowed = BIT(ADB_BLOCK_ADB);
size_t sz;
if (IS_ERR(is)) return PTR_ERR(is);
@ -167,20 +175,17 @@ static int __adb_m_stream(struct adb *db, struct apk_istream *is, uint32_t expec
do {
r = apk_istream_read_max(is, &blk, sizeof blk);
if (r == 0) {
if (!trusted) r = -APKE_SIGNATURE_UNTRUSTED;
else if (!db->adb.ptr) r = -APKE_ADB_BLOCK;
goto done;
if (r != sizeof blk) break;
type = adb_block_type(&blk);
if (!(BIT(type) & allowed)) {
r = -APKE_ADB_BLOCK;
break;
}
if (r < 0 || r != sizeof blk) goto err;
if ((block_no++ == 0) != (adb_block_type(&blk) == ADB_BLOCK_ADB))
goto bad_msg;
sz = adb_block_size(&blk) - sizeof blk;
switch (adb_block_type(&blk)) {
switch (type) {
case ADB_BLOCK_ADB:
if (!APK_BLOB_IS_NULL(db->adb)) goto bad_msg;
allowed = BIT(ADB_BLOCK_SIG) | BIT(ADB_BLOCK_DATA) | BIT(ADB_BLOCK_DATAX);
db->adb.ptr = malloc(sz);
db->adb.len = adb_block_length(&blk);
if ((r = apk_istream_read(is, db->adb.ptr, sz)) < 0) goto err;
@ -188,7 +193,6 @@ static int __adb_m_stream(struct adb *db, struct apk_istream *is, uint32_t expec
if (r < 0) goto err;
continue;
case ADB_BLOCK_SIG:
if (APK_BLOB_IS_NULL(db->adb)) goto bad_msg;
sig = apk_istream_peek(is, sz);
if (IS_ERR(sig)) {
r = PTR_ERR(sig);
@ -199,27 +203,30 @@ static int __adb_m_stream(struct adb *db, struct apk_istream *is, uint32_t expec
trusted = 1;
break;
case ADB_BLOCK_DATA:
if (APK_BLOB_IS_NULL(db->adb)) goto bad_msg;
if (!trusted) {
r = -APKE_SIGNATURE_UNTRUSTED;
goto err;
}
allowed = BIT(ADB_BLOCK_DATA) | BIT(ADB_BLOCK_DATAX);
if (!trusted) goto err;
break;
case ADB_BLOCK_DATAX:
r = -APKE_ADB_BLOCK;
break;
default:
goto bad_msg;
}
apk_istream_segment(&seg, is, adb_block_size(&blk) - sizeof blk, 0);
apk_istream_segment(&seg, is, sz, 0);
r = cb(db, &blk, &seg.is);
if (r < 0) goto err;
if (r < 0) break;
r = apk_istream_close(&seg.is);
if (r < 0) goto err;
if (r < 0) break;
} while (1);
bad_msg:
r = -APKE_ADB_BLOCK;
err:
if (r >= 0) r = -APKE_ADB_BLOCK;
done:
if (r > 0) r = -APKE_ADB_BLOCK;
if (r == 0) {
if (!trusted) r = -APKE_SIGNATURE_UNTRUSTED;
else if (!db->adb.ptr) r = -APKE_ADB_BLOCK;
}
if (r != 0) {
free(db->adb.ptr);
db->adb = APK_BLOB_NULL;
}
return apk_istream_close_error(is, r);
}
@ -929,6 +936,8 @@ int adb_c_block(struct apk_ostream *os, uint32_t type, apk_blob_t val)
size_t padding = adb_block_padding(&blk);
int r;
if (val.len & ~0x3fffffff) return -APKE_ADB_LIMIT;
r = apk_ostream_write(os, &blk, sizeof blk);
if (r < 0) return r;
@ -990,6 +999,8 @@ int adb_c_block_copy(struct apk_ostream *os, struct adb_block *b, struct apk_ist
} else {
r = apk_stream_copy(is, os, blk_sz, 0, 0, 0);
}
if (r < 0) return r;
r = 0;
if (padding) {
r = apk_ostream_write(os, padding_zeroes, padding);
if (r < 0) return r;

View File

@ -54,8 +54,9 @@ struct adb_header {
/* Blocks */
#define ADB_BLOCK_ALIGNMENT 8
#define ADB_BLOCK_ADB 0
#define ADB_BLOCK_SIG 2
#define ADB_BLOCK_DATA 3
#define ADB_BLOCK_SIG 1
#define ADB_BLOCK_DATA 2
#define ADB_BLOCK_DATAX 3
struct adb_block {
uint32_t type_size;

View File

@ -16,6 +16,7 @@ struct apk_istream *adb_decompress(struct apk_istream *is, adb_comp_t *compressi
if (IS_ERR_OR_NULL(is)) return is;
uint8_t *buf = apk_istream_peek(is, 4);
if (IS_ERR(buf)) return ERR_PTR(apk_istream_close_error(is, PTR_ERR(buf)));
if (memcmp(buf, "ADB", 3) == 0) switch (buf[3]) {
case '.':
c = ADB_COMP_NONE;

View File

@ -84,10 +84,11 @@ static int adbsign_main(void *pctx, struct apk_ctx *ac, struct apk_string_array
ctx->ac = ac;
foreach_array_item(arg, args) {
memset(&ctx->vfy, 0, sizeof ctx->vfy);
struct apk_istream *is = adb_decompress(apk_istream_from_file_mmap(AT_FDCWD, *arg), &comp);
ctx->os = adb_compress(apk_ostream_to_file(AT_FDCWD, *arg, 0644), comp);
adb_m_process(&ctx->db, is, 0, 0, process_block);
process_signatures(ctx);
apk_ostream_cancel(ctx->os, adb_m_process(&ctx->db, is, 0, 0, process_block));
apk_ostream_cancel(ctx->os, process_signatures(ctx));
adb_free(&ctx->db);
r = apk_ostream_close(ctx->os);
if (r) apk_err(out, "%s: %s", *arg, apk_error_str(r));