0ed2d8e07d3806d78d03a77d2153f22f9d733a07 test: add BIP37 remote crash bug [CVE-2013-5700] test to p2p_filter.py (Sebastian Falbesoner)
Pull request description:
Integrates the missing message type `filteradd` to the test framework and checks that the BIP37 implementation is not vulnerable to the "remote crash bug" [CVE-2013-5700](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2013-5700) anymore. Prior to v.0.8.4, it was possible to trigger a division-by-zero error on the following line in the function `CBloomFilter::Hash()`:
f0d6487e29/src/bloom.cpp (L45)
By setting a zero-length filter via `filterload`, `vData.size()` is 0, so the modulo operation above, called on any .insert() or .contains() operation then crashed the node. The test uses the approach of just sending an arbitrary `filteradd` message after, which calls `CBloomFilter::insert()` (and in turn `CBloomFilter::Hash()`) on the node. The vulnerability was fixed by commit 37c6389c5a (an intentional covert fix, [according to gmaxwell](https://github.com/bitcoin/bitcoin/issues/18483#issuecomment-608224095)), which introduced flags `isEmpty`/`isFull` that wouldn't call the `Hash()` member function if `isFull` is true (set to true by default constructor).
To validate that the test fails if the implementation is vulnerable, one can simply set the flags to false in the member function `UpdateEmptyFull()` (that is called after a filter received via `filterload` is constructed), which activates the vulnerable code path calling `Hash` in any case on adding or testing for data in the filter:
```diff
diff --git a/src/bloom.cpp b/src/bloom.cpp
index bd6069b..ef294a3 100644
--- a/src/bloom.cpp
+++ b/src/bloom.cpp
@@ -199,8 +199,8 @@ void CBloomFilter::UpdateEmptyFull()
full &= vData[i] == 0xff;
empty &= vData[i] == 0;
}
- isFull = full;
- isEmpty = empty;
+ isFull = false;
+ isEmpty = false;
}
```
Resulting in:
```
$ ./p2p_filter.py
[...]
2020-04-03T14:38:59.593000Z TestFramework (INFO): Check that division-by-zero remote crash bug [CVE-2013-5700] is fixed
2020-04-03T14:38:59.695000Z TestFramework (ERROR): Assertion failed
[...]
[... some exceptions following ...]
```
ACKs for top commit:
naumenkogs:
utACK 0ed2d8e07d3806d78d03a77d2153f22f9d733a07
Tree-SHA512: 02d0253d13eab70c4bd007b0750c56a5a92d05d419d53033523eeb3ed80318bc95196ab90f7745ea3ac9ebae7caee3adbf2a055a40a4124e0915226e49018fe8
11eefa21d4