Bugs(smtp): AUTH extension does not allow AUTH param on MAIL FROM. Resolves #565 (#1728)

Author: rnwood

smtpserver/Rnwood.SmtpServer.Tests/Extensions/Auth/AuthExtensionProcessorTests.cs

@@ -13,6 +13,7 @@ public class AuthExtensionProcessorTests
     public async Task GetEHLOKeywords_ReturnsIdentifiers()
     {
         TestMocks mocks = new TestMocks();
+        mocks.Connection.Setup(c => c.MailVerb).Returns(new MailVerb());
         mocks.ServerOptions.Setup(sb => sb.IsAuthMechanismEnabled(
             It.IsAny<IConnection>(),
             It.IsAny<IAuthMechanism>()
@@ -33,4 +34,61 @@ public async Task GetEHLOKeywords_ReturnsIdentifiers()
             Assert.Contains(ids, id => id == "PLAIN");
         }
     }
+
+    [Fact]
+    public async Task MailFrom_AllowsAuthParameterWithValue()
+    {
+        TestMocks mocks = new TestMocks();
+        mocks.Connection.Setup(c => c.MailVerb).Returns(new MailVerb());
+        mocks.Connection.Setup(c => c.NewMessage()).ReturnsAsync(() => {
+            var message = new MemoryMessageBuilder();
+            mocks.Connection.Setup(c => c.CurrentMessage).Returns(message);
+            return message;
+        });
+
+
+        AuthExtensionProcessor authExtensionProcessor = new AuthExtensionProcessor(mocks.Connection.Object);
+        await mocks.Connection.Object.MailVerb.FromSubVerb.Process(mocks.Connection.Object, new SmtpCommand("MAIL FROM:<[email protected]> [email protected]"));
+
+        mocks.VerifyWriteResponse(StandardSmtpResponseCode.OK);
+    }
+
+    [Fact]
+    public async Task MailFrom_AllowsAuthParameterWithEmptyPlaceholderValue()
+    {
+        TestMocks mocks = new TestMocks();
+        mocks.Connection.Setup(c => c.MailVerb).Returns(new MailVerb());
+        mocks.Connection.Setup(c => c.NewMessage()).ReturnsAsync(() => {
+            var message = new MemoryMessageBuilder();
+            mocks.Connection.Setup(c => c.CurrentMessage).Returns(message);
+            return message;
+        });
+
+
+        AuthExtensionProcessor authExtensionProcessor = new AuthExtensionProcessor(mocks.Connection.Object);
+        await mocks.Connection.Object.MailVerb.FromSubVerb.Process(mocks.Connection.Object, new SmtpCommand("MAIL FROM:<[email protected]> AUTH=<>"));
+
+        mocks.VerifyWriteResponse(StandardSmtpResponseCode.OK);
+    }
+
+    [Fact]
+    public async Task MailFrom_DoesNotAllowAuthParameterWithEmptyValue()
+    {
+        TestMocks mocks = new TestMocks();
+        mocks.Connection.Setup(c => c.MailVerb).Returns(new MailVerb());
+        mocks.Connection.Setup(c => c.NewMessage()).ReturnsAsync(() => {
+            var message = new MemoryMessageBuilder();
+            mocks.Connection.Setup(c => c.CurrentMessage).Returns(message);
+            return message;
+        });
+
+
+        AuthExtensionProcessor authExtensionProcessor = new AuthExtensionProcessor(mocks.Connection.Object);
+
+        var exception = await Assert.ThrowsAsync<SmtpServerException>(async () =>
+        {
+            await mocks.Connection.Object.MailVerb.FromSubVerb.Process(mocks.Connection.Object, new SmtpCommand("MAIL FROM:<[email protected]> AUTH="));
+        });
+        Assert.Equal((int) StandardSmtpResponseCode.SyntaxErrorInCommandArguments, exception.SmtpResponse.Code);
+    }
 }

smtpserver/Rnwood.SmtpServer/Extensions/Auth/AuthExtensionProcessor.cs

@@ -35,6 +35,8 @@ public AuthExtensionProcessor(IConnection connection)
         }
 
         connection.VerbMap.SetVerbProcessor("AUTH", new AuthVerb(this));
+
+        connection.MailVerb.FromSubVerb.ParameterProcessorMap.SetProcessor("AUTH", new AuthMailFromParameterProcessor());
     }
 
     /// <summary>
@@ -86,4 +88,17 @@ protected async Task<IEnumerable<IAuthMechanism>> GetEnabledAuthMechanisms()
 
         return result;
     }
+
+    private class AuthMailFromParameterProcessor : IParameterProcessor
+    {
+        public Task SetParameter(IConnection connection, string key, string value)
+        {
+            if (string.IsNullOrEmpty(value))
+            {
+                throw new SmtpServerException(new SmtpResponse(StandardSmtpResponseCode.SyntaxErrorInCommandArguments, "AUTH parameter must have a value or <>"));
+            }
+
+            return Task.CompletedTask;
+        }
+    }
 }