Go crypto/x509 vulnerabilities

The Go standard library (crypto/x509) added a denylist of known intermediate certificates no longer considered trustworthy. This defends against cases where system trust stores may not be updated without further action.

During chain building, the amount of work is not correctly limited when a large number of intermediate certificates are passed in VerifyOptions.Intermediates, which can lead to denial of service. This affects both direct users of crypto/x509 and users of crypto/tls.

Within HostnameError.Error(), there is no limit to the number of hosts printed when constructing an error string, and the string is built by repeated concatenation, leading to quadratic runtime. A certificate provided by a malicious actor can result in excessive resource consumption.