DKIM: downcase algorithms, accept ED25519.

src/storage/zone.cr

@@ -463,6 +463,7 @@ class DNSManager::Storage::Zone
 		end
 		enum SignatureAlgorithm
 			RSA
+			ED25519
 		end
 		enum HashAlgorithm
 			SHA256
@@ -478,7 +479,7 @@ class DNSManager::Storage::Zone
 			def initialize(@v, @h, @k, @p, @n)
 			end
 			def to_s(io : IO)
-				io << "v=#{v};h=#{h};k=#{k};p=#{p}"
+				io << "v=#{v};h=#{h.to_s.downcase};k=#{k.to_s.downcase};p=#{p}"
 				io << ";n=#{n}" unless n == ""
 			end
 		end