Optimize DkimPublicKeyRecordParser

nager · Jan 27, 2025 · 62cfc74 · 62cfc74
1 parent 8d77a31
commit 62cfc74
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Showing 4 changed files with 133 additions and 15 deletions.
diff --git a/src/Nager.EmailAuthentication.UnitTest/DkimPublicKeyRecordParserTests/BasicTest.cs b/src/Nager.EmailAuthentication.UnitTest/DkimPublicKeyRecordParserTests/BasicTest.cs
@@ -4,15 +4,39 @@
     public sealed class BasicTest
     {
         [TestMethod]
-        public void TryParse_ValidDkimHeaderString1_ReturnsTrueAndPopulatesDataFragment()
+        public void TryParse_ValidDkimPublicKeyRecord1_ReturnsTrueAndPopulatesDataFragment()
         {
             var dkimPublicKeyRecord = "v=DKIM1; k=rsa; p=MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAuu8v3TAGlg2cKEVtHbqh5QfebUSdVp2qwH4NFaIG/rEsBshHI97fdP6TqiJCmpLhK8mHSQMit2HiHAEUApa0xAw7SI68XiBr6epKpTkHaUx27C/kjyuxYmGFOJy6mrDzeC2E5+Lp1u9QifjuBtUk78ORSA+EXeEMxssHy51NdHT0BlZGk1M+wXTxniQ2d198gDVjjqRGM433Q0AP6uSJac9LQj80tHkWrnr/bjct7EOdtF+6mDl4qjAaJTruk03Xt3Alaj+DIOPmnwP1mbPLQmK4blnzM7jwQc2kZz9gSJocc0nhs8KfuR6Xj23iSOJV+WEt6WoLoJzSl8/Dx5CKJwIDAQAB";
 
             var isSuccessful = DkimPublicKeyRecordParser.TryParse(dkimPublicKeyRecord, out var dkimPublicKeyRecordDataFragment, out var parsingResults);
 
             Assert.IsTrue(isSuccessful);
             Assert.IsNotNull(dkimPublicKeyRecordDataFragment);
-            //Assert.IsNull(parsingResults, "ParsingResults is not null");
+            Assert.IsNull(parsingResults, "ParsingResults is not null");
+        }
+
+        [TestMethod]
+        public void TryParse_InvalidDkimPublicKeyRecord2_ReturnsTrueAndPopulatesDataFragment()
+        {
+            var dkimPublicKeyRecord = "v=DKIM1; k=rsa; p=";
+
+            var isSuccessful = DkimPublicKeyRecordParser.TryParse(dkimPublicKeyRecord, out var dkimPublicKeyRecordDataFragment, out var parsingResults);
+
+            Assert.IsTrue(isSuccessful);
+            Assert.IsNotNull(dkimPublicKeyRecordDataFragment);
+            Assert.IsNotNull(parsingResults, "ParsingResults is null");
+        }
+
+        [TestMethod]
+        public void TryParse_InvalidDkimPublicKeyRecord3_ReturnsTrueAndPopulatesDataFragment()
+        {
+            var dkimPublicKeyRecord = "v=DKIM1; k=rsa; p=1";
+
+            var isSuccessful = DkimPublicKeyRecordParser.TryParse(dkimPublicKeyRecord, out var dkimPublicKeyRecordDataFragment, out var parsingResults);
+
+            Assert.IsTrue(isSuccessful);
+            Assert.IsNotNull(dkimPublicKeyRecordDataFragment);
+            Assert.IsNotNull(parsingResults, "ParsingResults is null");
         }
     }
 }
diff --git a/src/Nager.EmailAuthentication.UnitTest/DkimSignatureParserTests/BasicTest.cs b/src/Nager.EmailAuthentication.UnitTest/DkimSignatureParserTests/BasicTest.cs
@@ -4,7 +4,7 @@
     public sealed class BasicTest
     {
         [TestMethod]
-        public void TryParse_ValidDkimHeaderString1_ReturnsTrueAndPopulatesDataFragment()
+        public void TryParse_ValidDkimSignature1_ReturnsTrueAndPopulatesDataFragment()
         {
             var dkimSignature = "v=1; a=rsa-sha256; c=relaxed/simple; q=dns/txt; d=domain.com; [email protected]; s=mailjet; x=1737017824; h=message-id:from:from:reply-to:to:to:subject:subject:date:date:list-unsubscribe-post:list-unsubscribe:feedback-id:x-csa-complaints:x-mj-mid:x-report-abuse-to:mime-version:content-type; bh=TyN/x6t3AOfI298rgJAgZHgdWcq/XLISGen5nN3NLAc=; b=HLCLiikV92Ku/k9mGlZM0bmqPjKggGnMI0igqhXmPRzPJUC+5SUWRS6/FLUpxbX6AUGJRDYQnKKMtp6uZkYVuKG8SPZ01cUkvIiiAkczb4bK6IVvPbZOnsWqHkD6EvK3TrpIhgFfGLlcG+zIwgdDZ3O++uhpJkIX1WJlkXZYqxQ=";
 

diff --git a/src/Nager.EmailAuthentication/DkimPublicKeyRecordParser.cs b/src/Nager.EmailAuthentication/DkimPublicKeyRecordParser.cs
@@ -1,5 +1,6 @@
 using Nager.EmailAuthentication.Handlers;
 using Nager.EmailAuthentication.Models;
+using System.Buffers.Text;
 
 namespace Nager.EmailAuthentication
 {
@@ -35,34 +36,31 @@ public static bool TryParse(
         {
             var handlers = new Dictionary<string, MappingHandler<DkimPublicKeyRecordDataFragment>>
             {
-                {
-                    "v", new MappingHandler<DkimPublicKeyRecordDataFragment>
-                    {
-                        Map = (dataFragment, value) => dataFragment.Version = value,
-                    }
-                },
                 {
                     "p", new MappingHandler<DkimPublicKeyRecordDataFragment>
                     {
                         Map = (dataFragment, value) => dataFragment.PublicKeyData = value,
+                        Validate = ValidatePublicKeyData
                     }
                 },
                 {
-                    "n", new MappingHandler<DkimPublicKeyRecordDataFragment>
+                    "v", new MappingHandler<DkimPublicKeyRecordDataFragment>
                     {
-                        Map = (dataFragment, value) => dataFragment.Notes = value
+                        Map = (dataFragment, value) => dataFragment.Version = value,
+                        Validate = ValidateVersion
                     }
                 },
                 {
                     "k", new MappingHandler<DkimPublicKeyRecordDataFragment>
                     {
-                        Map = (dataFragment, value) => dataFragment.KeyType = value
+                        Map = (dataFragment, value) => dataFragment.KeyType = value,
+                        Validate = ValidateKeyType
                     }
                 },
                 {
-                    "g", new MappingHandler<DkimPublicKeyRecordDataFragment>
+                    "n", new MappingHandler<DkimPublicKeyRecordDataFragment>
                     {
-                        Map = (dataFragment, value) => dataFragment.Granularity = value
+                        Map = (dataFragment, value) => dataFragment.Notes = value
                     }
                 },
                 {
@@ -71,10 +69,106 @@ public static bool TryParse(
                         Map = (dataFragment, value) => dataFragment.Flags = value
                     }
                 },
+                {
+                    "g", new MappingHandler<DkimPublicKeyRecordDataFragment>
+                    {
+                        Map = (dataFragment, value) => dataFragment.Granularity = value,
+                        Validate = ValidateGranularity
+                    }
+                }
             };
 
             var parserBase = new KeyValueParserBase<DkimPublicKeyRecordDataFragment>(handlers);
             return parserBase.TryParse(dkimPublicKeyRecord, out dkimPublicKeyRecordDataFragment, out parsingResults);
         }
+
+        private static ParsingResult[] ValidatePublicKeyData(ValidateRequest validateRequest)
+        {
+            if (string.IsNullOrEmpty(validateRequest.Value))
+            {
+                return
+                [
+                    new ParsingResult
+                    {
+                        Status = ParsingStatus.Critical,
+                        Message = "Public key data is emtpty"
+                    }
+                ];
+            }
+
+            if (Base64.IsValid(validateRequest.Value))
+            {
+                return [];
+            }
+
+            return
+            [
+                new ParsingResult
+                {
+                    Status = ParsingStatus.Critical,
+                    Message = "Invalid Public Key data, not base64 encoded"
+                }
+            ];
+        }
+
+        private static ParsingResult[] ValidateVersion(ValidateRequest validateRequest)
+        {
+            var errors = new List<ParsingResult>();
+
+            if (string.IsNullOrEmpty(validateRequest.Value))
+            {
+                return [
+                    new ParsingResult
+                    {
+                        Status = ParsingStatus.Critical,
+                        Message = "DKIM record is invalid: it must start with 'v=DKIM1' if it specified"
+                    }
+                ];
+            }
+
+            if (validateRequest.Value.Equals("DKIM1", StringComparison.OrdinalIgnoreCase))
+            {
+                return [];
+            }
+
+            return [
+                new ParsingResult
+                {
+                    Status = ParsingStatus.Critical,
+                    Message = "DKIM record is invalid: it must start with 'v=DKIM1'."
+                }
+            ];
+        }
+
+        private static ParsingResult[] ValidateGranularity(ValidateRequest validateRequest)
+        {
+            return
+            [
+                new ParsingResult
+                {
+                    Status = ParsingStatus.Warning,
+                    Message = "Granularity is deprecated."
+                }
+            ];
+        }
+
+        private static ParsingResult[] ValidateKeyType(ValidateRequest validateRequest)
+        {
+            var allowedKeyTypes = new string[] { "rsa", "ed25519 " };
+
+            if (allowedKeyTypes.Contains(validateRequest.Value, StringComparer.CurrentCultureIgnoreCase))
+            {
+                return [];
+            }
+
+            return
+            [
+                new ParsingResult
+                {
+                    Status = ParsingStatus.Critical,
+                    Message = "The type of the key is invalid"
+                }
+            ];
+        }
     }
 }
diff --git a/src/Nager.EmailAuthentication/Nager.EmailAuthentication.csproj b/src/Nager.EmailAuthentication/Nager.EmailAuthentication.csproj
@@ -20,7 +20,7 @@
 
     <TargetFrameworks>net8.0;net9.0</TargetFrameworks>
 
-    <Version>1.4.0</Version>
+    <Version>1.4.1</Version>
   </PropertyGroup>
 
   <ItemGroup>