* make sure client CA and auth type are set if CA is explicitly specified. added some simple tests to confirm the effect. * test certificates (forgot to add them in the previous commit) * made client auth policy configurable with new client_auth option. README has been updated accordingly. * fix editorial in README
2.1 KiB
tls
Name
tls - allows you to configure the server certificates for the TLS and gRPC servers.
Description
CoreDNS supports queries that are encrypted using TLS (DNS over Transport Layer Security, RFC 7858) or are using gRPC (https://grpc.io/, not an IETF standard). Normally DNS traffic isn't encrypted at all (DNSSEC only signs resource records).
The tls "plugin" allows you to configure the cryptographic keys that are needed for both
DNS-over-TLS and DNS-over-gRPC. If the tls
directive is omitted, then no encryption takes place.
The gRPC protobuffer is defined in pb/dns.proto
. It defines the proto as a simple wrapper for the
wire data of a DNS message.
Syntax
tls CERT KEY [CA]
Parameter CA is optional. If not set, system CAs can be used to verify the client certificate
tls CERT KEY [CA] {
client_auth nocert|request|require|verify_if_given|require_and_verify
}
If client_auth option is specified, it controls the client authentication policy. The option value corresponds to the ClientAuthType values of the Go tls package: NoClientCert, RequestClientCert, RequireAnyClientCert, VerifyClientCertIfGiven, and RequireAndVerifyClientCert, respectively. The default is "nocert". Note that it makes no sense to specify parameter CA unless this option is set to verify_if_given or require_and_verify.
Examples
Start a DNS-over-TLS server that picks up incoming DNS-over-TLS queries on port 5553 and uses the
nameservers defined in /etc/resolv.conf
to resolve the query. This proxy path uses plain old DNS.
tls://.:5553 {
tls cert.pem key.pem ca.pem
forward . /etc/resolv.conf
}
Start a DNS-over-gRPC server that is similar to the previous example, but using DNS-over-gRPC for incoming queries.
grpc://. {
tls cert.pem key.pem ca.pem
forward . /etc/resolv.conf
}
Only Knot DNS' kdig
supports DNS-over-TLS queries, no command line client supports gRPC making
debugging these transports harder than it should be.
Also See
RFC 7858 and https://grpc.io.