CSHARP-5471: Incorrectly resolving the authentication mechanism param… (#1605)

Co-authored-by: Oleksandr Poliakov <31327136+sanych-sun@users.noreply.github.com>

Author: papafe

src/MongoDB.Driver/Core/Configuration/ConnectionString.cs

@@ -684,29 +684,30 @@ private ConnectionString BuildResolvedConnectionString(ConnectionStringScheme re
                 .AllKeys
                 .SelectMany(key => resolvedOptions
                     .GetValues(key)
-                    .Select(value => $"{key}={Uri.EscapeDataString(value)}")));
+                    .Select(value => $"{key}={EscapeOptionValue(key, value)}")));
 
             if (mergedOptions.Count > 0)
             {
                 connectionString += "?" + string.Join("&", mergedOptions);
             }
 
             return new ConnectionString(connectionString, isResolved: true);
+
+            string EscapeOptionValue(string key, string value)
+                => string.Equals(key, "authmechanismproperties", StringComparison.OrdinalIgnoreCase) ? value : Uri.EscapeDataString(value);
+
         }
 
         private void ExtractScheme(Match match)
         {
             var schemeGroup = match.Groups["scheme"];
-            if (schemeGroup.Success)
+            if (schemeGroup.Success && schemeGroup.Value == "mongodb+srv")
             {
-                if (schemeGroup.Value == "mongodb+srv")
+                _scheme = ConnectionStringScheme.MongoDBPlusSrv;
+                if (!_tls.HasValue)
                 {
-                    _scheme = ConnectionStringScheme.MongoDBPlusSrv;
-                    if (!_tls.HasValue)
-                    {
-                        _tls = true;
-                        _allOptions.Add("tls", "true");
-                    }
+                    _tls = true;
+                    _allOptions.Add("tls", "true");
                 }
             }
         }
@@ -761,7 +762,13 @@ private void ExtractOptions(Match match)
                 var parts = option.Value.Split('=');
                 var name = parts[0].Trim();
                 var value = parts[1].Trim();
-                _allOptions.Add(name, Uri.UnescapeDataString(value));
+                // Should not decode authmechanismproperties before splitting by separator.
+                if (!string.Equals(name, "authmechanismproperties", StringComparison.OrdinalIgnoreCase))
+                {
+                    value = Uri.UnescapeDataString(value);
+                }
+
+                _allOptions.Add(name, value);
                 ParseOption(name, value);
             }
         }
@@ -905,12 +912,6 @@ string ProtectConnectionString(string connectionString)
 
         private void ParseOption(string name, string value)
         {
-            // Should not decode authmechanismproperties before splitting by separator.
-            if (!string.Equals(name, "authmechanismproperties", StringComparison.OrdinalIgnoreCase))
-            {
-                value = Uri.UnescapeDataString(value);
-            }
-
             switch (name.ToLowerInvariant())
             {
                 case "appname":

tests/MongoDB.Driver.Tests/MongoCredentialTests.cs

@@ -155,5 +155,29 @@ public void TestMechanismProperty()
             Assert.Equal("awesome", withProperties.GetMechanismProperty<string>("SPN", null));
             Assert.Equal(10, withProperties.GetMechanismProperty<int>("OTHER", 0));
         }
+
+        [Theory]
+        [InlineData("mongodb+srv://<cluster>/?retryWrites=true&authMechanism=MONGODB-OIDC&authSource=%24external&authMechanismProperties=ENVIRONMENT:azure,prop:ab%2Ccd%2Cef%2Cjh,TOKEN_RESOURCE:mongodb%3A%2F%2Ftest-cluster,ANOTHER:test")]
+        [InlineData("mongodb+srv://<cluster>/?retryWrites=true&authMechanism=MONGODB-OIDC&authSource=%24external&authMechanismProperties=ENVIRONMENT:azure,prop:ab%2Ccd%2Cef%2Cjh,TOKEN_RESOURCE:mongodb://test-cluster,ANOTHER:test")]
+        public void TestMechanismPropertyFromUnresolvedConnectionString(string url)
+        {
+            var mongoConnection = MongoClientSettings.FromConnectionString(url);
+            mongoConnection.Credential.GetMechanismProperty("ENVIRONMENT", "").Should().Be("azure");
+            mongoConnection.Credential.GetMechanismProperty("prop", "").Should().Be("ab,cd,ef,jh");
+            mongoConnection.Credential.GetMechanismProperty("TOKEN_RESOURCE", "").Should().Be("mongodb://test-cluster");
+            mongoConnection.Credential.GetMechanismProperty("ANOTHER", "").Should().Be("test");
+        }
+
+        [Theory]
+        [InlineData("mongodb://user@localhost/?authMechanism=MONGODB-OIDC&authSource=$external&authMechanismProperties=ENVIRONMENT:azure,prop:ab%2Ccd%2Cef%2Cjh,TOKEN_RESOURCE:mongodb%3A%2F%2Ftest-cluster,ANOTHER:test")]
+        [InlineData("mongodb://user@localhost/?authMechanism=MONGODB-OIDC&authSource=$external&authMechanismProperties=ENVIRONMENT:azure,prop:ab%2Ccd%2Cef%2Cjh,TOKEN_RESOURCE:mongodb://test-cluster,ANOTHER:test")]
+        public void TestMechanismPropertyFromResolvedConnectionString(string url)
+        {
+            var mongoConnection = MongoClientSettings.FromConnectionString(url);
+            mongoConnection.Credential.GetMechanismProperty("ENVIRONMENT", "").Should().Be("azure");
+            mongoConnection.Credential.GetMechanismProperty("prop", "").Should().Be("ab,cd,ef,jh");
+            mongoConnection.Credential.GetMechanismProperty("TOKEN_RESOURCE", "").Should().Be("mongodb://test-cluster");
+            mongoConnection.Credential.GetMechanismProperty("ANOTHER", "").Should().Be("test");
+        }
     }
 }