Only erase credentials that match the username/password if specified

common/src/Microsoft.Git.CredentialManager/Commands/EraseCommand.cs

@@ -1,6 +1,8 @@
 // Copyright (c) Microsoft Corporation. All rights reserved.
 // Licensed under the MIT license.
+using System;
 using System.Threading.Tasks;
+using Microsoft.Git.CredentialManager.SecureStorage;
 
 namespace Microsoft.Git.CredentialManager.Commands
 {
@@ -16,13 +18,46 @@ public EraseCommand(IHostProviderRegistry hostProviderRegistry)
 
         protected override Task ExecuteInternalAsync(ICommandContext context, InputArguments input, IHostProvider provider, string credentialKey)
         {
-            context.Trace.WriteLine("Erasing credential...");
+            // Try to locate an existing credential with the computed key
+            context.Trace.WriteLine("Looking for existing credential in store...");
+            ICredential credential = context.CredentialStore.Get(credentialKey);
+            if (credential == null)
+            {
+                context.Trace.WriteLine("No stored credential was found.");
+                return Task.CompletedTask;
+            }
+            else
+            {
+                context.Trace.WriteLine("Existing credential found.");
+            }
+
+            // If we've been given a specific username and/or password we should only proceed
+            // to erase the stored credential if they match exactly
+            if (!string.IsNullOrWhiteSpace(input.UserName) && !StringComparer.Ordinal.Equals(input.UserName, credential.UserName))
+            {
+                context.Trace.WriteLine("Stored username does not match specified username - not erasing credential.");
+                context.Trace.WriteLine($"\tInput  username={input.UserName}");
+                context.Trace.WriteLine($"\tStored username={credential.UserName}");
+                return Task.CompletedTask;
+            }
+
+            if (!string.IsNullOrWhiteSpace(input.Password) && !StringComparer.Ordinal.Equals(input.Password, credential.Password))
+            {
+                context.Trace.WriteLine("Stored password does not match specified password - not erasing credential.");
+                context.Trace.WriteLineSecrets("\tInput  password={0}", new object[] {input.Password});
+                context.Trace.WriteLineSecrets("\tStored password={0}", new object[] {credential.Password});
+                return Task.CompletedTask;
+            }
 
-            // Delete the credential in the store.
+            context.Trace.WriteLine("Erasing stored credential...");
             if (context.CredentialStore.Remove(credentialKey))
             {
                 context.Trace.WriteLine("Credential was successfully erased.");
             }
+            else
+            {
+                context.Trace.WriteLine("Credential erase failed.");
+            }
 
             return Task.CompletedTask;
         }

common/tests/Microsoft.Git.CredentialManager.Tests/Commands/EraseCommandTests.cs

@@ -30,7 +30,7 @@ public void EraseCommand_CanExecuteAsync(string argString, bool expected)
         }
 
         [Fact]
-        public async Task EraseCommand_ExecuteAsync_CredentialExists_ErasesCredential()
+        public async Task EraseCommand_ExecuteAsync_NoInputUserPass_CredentialExists_ErasesCredential()
         {
             const string testCredentialKey = "test-cred-key";
 
@@ -57,6 +57,90 @@ public async Task EraseCommand_ExecuteAsync_CredentialExists_ErasesCredential()
             Assert.True(context.CredentialStore.ContainsKey("git:credential2"));
         }
 
+        [Fact]
+        public async Task EraseCommand_ExecuteAsync_InputUserPass_CredentialExists_UserNotMatch_DoesNothing()
+        {
+            const string testUserName = "john.doe";
+            const string testPassword = "letmein123";
+            const string testCredentialKey = "test-cred-key";
+            string stdIn = $"username={testUserName}\npassword={testPassword}\n\n";
+
+            var provider = new TestHostProvider {CredentialKey = testCredentialKey};
+            var providerRegistry = new TestHostProviderRegistry {Provider = provider};
+            var context = new TestCommandContext
+            {
+                StdIn = stdIn,
+                CredentialStore =
+                {
+                    [$"git:{testCredentialKey}"] = new GitCredential("different-username", testPassword),
+                }
+            };
+
+            string[] cmdArgs = {"erase"};
+            var command = new EraseCommand(providerRegistry);
+
+            await command.ExecuteAsync(context, cmdArgs);
+
+            Assert.Equal(1, context.CredentialStore.Count);
+            Assert.True(context.CredentialStore.ContainsKey($"git:{testCredentialKey}"));
+        }
+
+        [Fact]
+        public async Task EraseCommand_ExecuteAsync_InputUserPass_CredentialExists_PassNotMatch_DoesNothing()
+        {
+            const string testUserName = "john.doe";
+            const string testPassword = "letmein123";
+            const string testCredentialKey = "test-cred-key";
+            string stdIn = $"username={testUserName}\npassword={testPassword}\n\n";
+
+            var provider = new TestHostProvider {CredentialKey = testCredentialKey};
+            var providerRegistry = new TestHostProviderRegistry {Provider = provider};
+            var context = new TestCommandContext
+            {
+                StdIn = stdIn,
+                CredentialStore =
+                {
+                    [$"git:{testCredentialKey}"] = new GitCredential(testUserName, "different-password"),
+                }
+            };
+
+            string[] cmdArgs = {"erase"};
+            var command = new EraseCommand(providerRegistry);
+
+            await command.ExecuteAsync(context, cmdArgs);
+
+            Assert.Equal(1, context.CredentialStore.Count);
+            Assert.True(context.CredentialStore.ContainsKey($"git:{testCredentialKey}"));
+        }
+
+        [Fact]
+        public async Task EraseCommand_ExecuteAsync_InputUserPass_CredentialExists_UserPassMatch_ErasesCredential()
+        {
+            const string testUserName = "john.doe";
+            const string testPassword = "letmein123";
+            const string testCredentialKey = "test-cred-key";
+            string stdIn = $"username={testUserName}\npassword={testPassword}\n\n";
+
+            var provider = new TestHostProvider {CredentialKey = testCredentialKey};
+            var providerRegistry = new TestHostProviderRegistry {Provider = provider};
+            var context = new TestCommandContext
+            {
+                StdIn = stdIn,
+                CredentialStore =
+                {
+                    [$"git:{testCredentialKey}"] = new GitCredential(testUserName, testPassword),
+                }
+            };
+
+            string[] cmdArgs = {"erase"};
+            var command = new EraseCommand(providerRegistry);
+
+            await command.ExecuteAsync(context, cmdArgs);
+
+            Assert.Equal(0, context.CredentialStore.Count);
+            Assert.False(context.CredentialStore.ContainsKey($"git:{testCredentialKey}"));
+        }
+
         [Fact]
         public async Task EraseCommand_ExecuteAsync_NoCredential_DoesNothing()
         {