# Functions
DefaultVerifyOptions returns VerifyOptions that use the system root certificates, current time, and requires certificates to be valid for client auth (x509.ExtKeyUsageClientAuth).
New returns a request.Authenticator that verifies client certificates using the provided VerifyOptions, and converts valid certificate chains into user.Info using the provided UserConversion.
NewVerifier create a request.Authenticator by verifying a client cert on the request, then delegating to the wrapped auth.
# Variables
CommonNameUserConversion builds user info from a certificate chain using the subject's CommonName.
DNSNameUserConversion builds user info from a certificate chain using the first DNSName on the certificate.
EmailAddressUserConversion builds user info from a certificate chain using the first EmailAddress on the certificate.
# Structs
Authenticator implements request.Authenticator by extracting user info from verified client certificates.
Verifier implements request.Authenticator by verifying a client cert on the request, then delegating to the wrapped auth.
# Interfaces
UserConversion defines an interface for extracting user info from a client certificate chain.
# Type aliases
UserConversionFunc is a function that implements the UserConversion interface.