From 9b6457f57500df97d89d95e061ad68e2fc60f0db Mon Sep 17 00:00:00 2001
From: Philippe PITTOLI <karchnu@karchnu.fr>
Date: Mon, 15 Apr 2024 23:13:57 +0200
Subject: [PATCH] DMARC.

---
 src/storage/zone.cr | 147 +++++++++++++++++++++++++++++++++++++++++---
 1 file changed, 140 insertions(+), 7 deletions(-)

diff --git a/src/storage/zone.cr b/src/storage/zone.cr
index 6184ef8..4bec0c2 100644
--- a/src/storage/zone.cr
+++ b/src/storage/zone.cr
@@ -521,11 +521,11 @@ class DNSManager::Storage::Zone
 			errors = [] of Error
 
 			unless Zone.is_subdomain_valid? @name
-				errors << "CNAME invalid subdomain: #{@name}"
+				errors << "DKIM invalid subdomain: #{@name}"
 			end
 
 			if @ttl < Zone.ttl_limit_min
-				errors << "CNAME invalid ttl: #{@ttl}, shouldn't be less than #{Zone.ttl_limit_min}"
+				errors << "DKIM invalid ttl: #{@ttl}, shouldn't be less than #{Zone.ttl_limit_min}"
 			end
 			errors
 		end
@@ -542,22 +542,155 @@ class DNSManager::Storage::Zone
 
 	# TODO
 	class DMARC < ResourceRecord
-		def initialize(@name, @ttl, @target)
+		enum Version
+			DMARC1
+		end
+
+		class DMARCURI
+			include JSON::Serializable
+			property mail : String
+			property limit : UInt32? = nil
+
+			def to_s(io : IO)
+				io << "#{mail}"
+				if l = @limit
+					io << "!#{l}k"
+				end
+			end
+		end
+
+		enum ReportFormat
+			AFRF
+		end
+
+		enum ConsistencyPolicy
+			Strict
+			Relaxed
+		end
+
+		enum Policy
+			None
+			Quarantine
+			Reject
+		end
+
+		enum ReportOccasion
+			BOTH
+			DKIMONLY
+			SPFONLY
+			ANY
+		end
+
+		class DMARCProperties
+			include JSON::Serializable
+
+			property p     : Policy
+			property sp    : Policy? = nil
+			property v     : Version = Version::DMARC1
+			property adkim : ConsistencyPolicy? = nil
+			property aspf  : ConsistencyPolicy? = nil
+			property pct   : UInt32? = nil
+			property fo    : ReportOccasion? = nil
+			property rua   : Array(DMARCURI)? = nil
+			property ruf   : Array(DMARCURI)? = nil
+			property rf    : Array(ReportFormat)? = nil
+			property ri    : UInt32
+
+			def initialize(@p, @sp, @v, @adkim, @aspf, @pct, @fo, @rua, @ruf, @rf, @ri)
+			end
+
+			def self.consistency_policy_to_bind9(p : ConsistencyPolicy)
+				p == ConsistencyPolicy::Strict ? "s" : "r"
+			end
+
+			def self.report_occasion_to_bind9(fo : ReportOccasion)
+				case fo
+				when ReportOccasion::BOTH
+					"0"
+				when ReportOccasion::DKIMONLY
+					"d"
+				when ReportOccasion::SPFONLY
+					"s"
+				else
+					"1"
+				end
+			end
+
+			def to_s(io : IO)
+				io << "v=#{v}"
+				io << ";p=#{@p.to_s.downcase}"
+				if val = @sp
+					io << ";sp=#{val.to_s.downcase}"
+				end
+				if val = adkim
+					io << ";adkim=#{DMARCProperties.consistency_policy_to_bind9(val)}"
+				end
+				if val = aspf
+					io << ";aspf=#{DMARCProperties.consistency_policy_to_bind9(val)}"
+				end
+				if val = pct
+					io << ";pct=#{val}"
+				end
+				if val = fo
+					io << ";fo=#{DMARCProperties.report_occasion_to_bind9(val)}"
+				end
+				if val = rua
+					io << ";rua="
+					arr = val.map { |x| x.to_s }
+					while arr.size > 1
+						io << arr.pop
+						io << ","
+					end
+					io << arr.pop
+				end
+				if val = ruf
+					io << ";ruf="
+					arr = val.map { |x| x.to_s }
+					while arr.size > 1
+						io << arr.pop
+						io << ","
+					end
+					io << arr.pop
+				end
+				if val = rf
+					io << ";rf=#{val}"
+				end
+				if val = ri
+					io << ";ri=#{val}"
+				end
+			end
+		end
+
+		property dmarc : DMARCProperties
+
+		def initialize(@name, @ttl, @target,
+		               p, sp, v, adkim, aspf, pct, fo, rua, ruf, rf, ri)
 			@rrtype = "DMARC"
+			@dmarc = DMARCProperties.new p, sp, v, adkim, aspf, pct, fo, rua, ruf, rf, ri
 		end
 
 		def get_errors : Array(Error)
 			errors = [] of Error
 
-			unless Zone.is_subdomain_valid? @name
-				errors << "CNAME invalid subdomain: #{@name}"
-			end
+			# TODO: label can (and is expected to) start with an underscore.
+			#unless Zone.is_subdomain_valid? @name
+			#	errors << "DMARC invalid subdomain: #{@name}"
+			#end
 
 			if @ttl < Zone.ttl_limit_min
-				errors << "CNAME invalid ttl: #{@ttl}, shouldn't be less than #{Zone.ttl_limit_min}"
+				errors << "DMARC invalid ttl: #{@ttl}, shouldn't be less than #{Zone.ttl_limit_min}"
 			end
 			errors
 		end
+
+		def to_s(io : IO)
+			io << "(#{ "%4d" % @rrid }) "
+			io << "#{ "%30s" % @name} #{ "%6d" % @ttl} DMARC #{split_line dmarc.to_s}\n"
+		end
+
+		def to_bind9(io : IO)
+			io << "#{@name} #{@ttl} IN TXT #{split_line dmarc.to_s}\n"
+		end
 	end
 
 	class MX < ResourceRecord