libp2p nodes vulnerable to attack using large RSA keys

Impact

A malicious peer can use large RSA keys to run a resource exhaustion attack & force a node to spend time doing signature verification of the large key. This vulnerability is present in the core/crypto module of go-libp2p and can occur during the Noise handshake and the libp2p x509 extension verification step. To prevent this attack, go-libp2p now restricts RSA keys to <= 8192 bits.

Patches

Users should upgrade their go-libp2p versions to >=v0.27.8, >= v0.28.2, or >=v0.29.1 To protect your application, it's necessary to update to these patch releases AND to use the updated Go compiler (1.20.7 or 1.19.12, respectively)

Workarounds

There are no known workarounds

References

The Golang crypto/tls package also had this vulnerability ("verifying certificate chains containing large RSA keys is slow” https://github.com/golang/go/issues/61460) Fix in golang/go crypto/tls: https://github.com/golang/go/commit/2350afd2e8ab054390e284c95d5b089c142db017 Fix in quic-go https://github.com/quic-go/quic-go/pull/4012