introduce PasswordExpiryUTC and OAuthRefreshToken

Add properties ICredential.PasswordExpiryUTC and
ICredential.OAuthRefreshToken. These correspond to Git credential
attributes password_expiry_utc and oauth_refresh_token, see
https://git-scm.com/docs/git-credential#IOFMT. Previously these
attributes were silently disarded.

Plumb these properties from input to host provider to credential store
to output.

Credential store support for these attributes is optional, marked by
new properties ICredentialStore.CanStorePasswordExpiryUTC and
ICredentialStore.CanStoreOAuthRefreshToken. Implement support in
CredentialCacheStore, SecretServiceCollection and
WindowsCredentialManager.

Add method IHostProvider.ValidateCredentialAsync. The default
implementation simply checks expiry.

Improve implementations of GenericHostProvider and GitLabHostProvider.
Previously, GetCredentialAsync saved credentials as a side effect. This
is no longer necessary. The workaround to store OAuth refresh tokens
under a separate service is no longer necessary assuming
CredentialStore.CanStoreOAuthRefreshToken. Querying GitLab to check
token expiration is no longer necessary assuming
CredentialStore.CanStorePasswordExpiryUTC.

src/shared/Core.Tests/Commands/GetCommandTests.cs

@@ -1,3 +1,4 @@
+using System;
 using System.Collections.Generic;
 using System.IO;
 using System.Text;
@@ -16,14 +17,21 @@ public async Task GetCommand_ExecuteAsync_CallsHostProviderAndWritesCredential()
         {
             const string testUserName = "john.doe";
             const string testPassword = "letmein123"; // [SuppressMessage("Microsoft.Security", "CS001:SecretInline", Justification="Fake credential")]
-            ICredential testCredential = new GitCredential(testUserName, testPassword);
+            const string testRefreshToken = "xyzzy";
+            const long testExpiry = 1919539847;
+            ICredential testCredential = new GitCredential(testUserName, testPassword) {
+                OAuthRefreshToken = testRefreshToken,
+                PasswordExpiry = DateTimeOffset.FromUnixTimeSeconds(testExpiry),
+            };
             var stdin = $"protocol=http\nhost=example.com\n\n";
             var expectedStdOutDict = new Dictionary<string, string>
             {
                 ["protocol"] = "http",
                 ["host"]     = "example.com",
                 ["username"] = testUserName,
-                ["password"] = testPassword
+                ["password"] = testPassword,
+                ["password_expiry_utc"] = testExpiry.ToString(),
+                ["oauth_refresh_token"] = testRefreshToken,
             };
 
             var providerMock = new Mock<IHostProvider>();

src/shared/Core.Tests/Commands/StoreCommandTests.cs

@@ -13,13 +13,17 @@ public async Task StoreCommand_ExecuteAsync_CallsHostProvider()
         {
             const string testUserName = "john.doe";
             const string testPassword = "letmein123"; // [SuppressMessage("Microsoft.Security", "CS001:SecretInline", Justification="Fake credential")]
-            var stdin = $"protocol=http\nhost=example.com\nusername={testUserName}\npassword={testPassword}\n\n";
+            const string testRefreshToken = "xyzzy";
+            const long testExpiry = 1919539847;
+            var stdin = $"protocol=http\nhost=example.com\nusername={testUserName}\npassword={testPassword}\noauth_refresh_token={testRefreshToken}\npassword_expiry_utc={testExpiry}\n\n";
             var expectedInput = new InputArguments(new Dictionary<string, string>
             {
                 ["protocol"] = "http",
                 ["host"]     = "example.com",
                 ["username"] = testUserName,
-                ["password"] = testPassword
+                ["password"] = testPassword,
+                ["oauth_refresh_token"] = testRefreshToken,
+                ["password_expiry_utc"] = testExpiry.ToString(),
             });
 
             var providerMock = new Mock<IHostProvider>();
@@ -46,7 +50,9 @@ bool AreInputArgumentsEquivalent(InputArguments a, InputArguments b)
                    a.Host     == b.Host &&
                    a.Path     == b.Path &&
                    a.UserName == b.UserName &&
-                   a.Password == b.Password;
+                   a.Password == b.Password &&
+                   a.OAuthRefreshToken == b.OAuthRefreshToken &&
+                   a.PasswordExpiry == b.PasswordExpiry;
         }
     }
 }

src/shared/Core.Tests/GenericHostProviderTests.cs

@@ -201,7 +201,6 @@ public async Task GenericHostProvider_GenerateCredentialAsync_OAuth_CompleteOAut
             const string testAcessToken = "OAUTH_TOKEN";
             const string testRefreshToken = "OAUTH_REFRESH_TOKEN";
             const string testResource = "https://git.example.com/foo";
-            const string expectedRefreshTokenService = "https://refresh_token.git.example.com/foo";
 
             var authMode = OAuthAuthenticationModes.Browser;
             string[] scopes = { "code:write", "code:read" };
@@ -249,7 +248,7 @@ public async Task GenericHostProvider_GenerateCredentialAsync_OAuth_CompleteOAut
                 .ReturnsAsync(new OAuth2TokenResult(testAcessToken, "access_token")
                 {
                     Scopes = scopes,
-                    RefreshToken = testRefreshToken
+                    RefreshToken = testRefreshToken,
                 });
 
             var provider = new GenericHostProvider(context, basicAuthMock.Object, wiaAuthMock.Object, oauthMock.Object);
@@ -259,10 +258,7 @@ public async Task GenericHostProvider_GenerateCredentialAsync_OAuth_CompleteOAut
             Assert.NotNull(credential);
             Assert.Equal(testUserName, credential.Account);
             Assert.Equal(testAcessToken, credential.Password);
-
-            Assert.True(context.CredentialStore.TryGet(expectedRefreshTokenService, null, out TestCredential refreshToken));
-            Assert.Equal(testUserName, refreshToken.Account);
-            Assert.Equal(testRefreshToken, refreshToken.Password);
+            Assert.Equal(testRefreshToken, credential.OAuthRefreshToken);
 
             oauthMock.Verify(x => x.GetAuthenticationModeAsync(testResource, OAuthAuthenticationModes.All), Times.Once);
             oauthMock.Verify(x => x.GetTokenByBrowserAsync(It.IsAny<OAuth2Client>(), scopes), Times.Once);

src/shared/Core.Tests/HostProviderTests.cs

@@ -1,4 +1,6 @@
+using System;
 using System.Collections.Generic;
+using System.Runtime;
 using System.Threading.Tasks;
 using GitCredentialManager.Tests.Objects;
 using Xunit;
@@ -15,16 +17,16 @@ public async Task HostProvider_GetCredentialAsync_CredentialExists_ReturnsExisti
             const string userName = "john.doe";
             const string password = "letmein123"; // [SuppressMessage("Microsoft.Security", "CS001:SecretInline", Justification="Fake credential")]
             const string service = "https://example.com";
+            const string refreshToken = "xyzzy";
+            DateTimeOffset expiry = DateTimeOffset.FromUnixTimeSeconds(1919539847);
             var input = new InputArguments(new Dictionary<string, string>
             {
                 ["protocol"] = "https",
                 ["host"] = "example.com",
-                ["username"] = userName,
-                ["password"] = password, // [SuppressMessage("Microsoft.Security", "CS001:SecretInline", Justification="Fake credential")]
             });
 
             var context = new TestCommandContext();
-            context.CredentialStore.Add(service, userName, password);
+            context.CredentialStore.Add(service, new TestCredential(service, userName, password) { OAuthRefreshToken = refreshToken, PasswordExpiry = expiry});
             var provider = new TestHostProvider(context)
             {
                 IsSupportedFunc = _ => true,
@@ -39,6 +41,8 @@ public async Task HostProvider_GetCredentialAsync_CredentialExists_ReturnsExisti
 
             Assert.Equal(userName, actualCredential.Account);
             Assert.Equal(password, actualCredential.Password);
+            Assert.Equal(refreshToken, actualCredential.OAuthRefreshToken);
+            Assert.Equal(expiry, actualCredential.PasswordExpiry);
         }
 
         [Fact]
@@ -50,8 +54,6 @@ public async Task HostProvider_GetCredentialAsync_CredentialDoesNotExist_Returns
             {
                 ["protocol"] = "https",
                 ["host"] = "example.com",
-                ["username"] = userName,
-                ["password"] = password, // [SuppressMessage("Microsoft.Security", "CS001:SecretInline", Justification="Fake credential")]
             });
 
             bool generateWasCalled = false;
@@ -73,6 +75,49 @@ public async Task HostProvider_GetCredentialAsync_CredentialDoesNotExist_Returns
             Assert.Equal(password, actualCredential.Password);
         }
 
+        [Fact]
+        public async Task HostProvider_GetCredentialAsync_InvalidCredentialStored_ReturnsNewGeneratedCredential()
+        {
+            const string userName = "john.doe";
+            const string password = "letmein123"; // [SuppressMessage("Microsoft.Security", "CS001:SecretInline", Justification="Fake credential")]
+            const string service = "https://example.com";
+            const string storedRefreshToken = "first";
+            const string refreshToken = "second";
+            var input = new InputArguments(new Dictionary<string, string>
+            {
+                ["protocol"] = "https",
+                ["host"] = "example.com",
+            });
+
+            bool generateWasCalled = false;
+            string refreshTokenSeenByGenerate = null;
+            var context = new TestCommandContext();
+            context.CredentialStore.Add(service, new TestCredential(service, "stored-user", "stored-password") { OAuthRefreshToken = storedRefreshToken});
+            var provider = new TestHostProvider(context)
+            {
+                ValidateCredentialFunc = (_, _) => false,
+                IsSupportedFunc = _ => true,
+                GenerateCredentialFunc = input =>
+                {
+                    generateWasCalled = true;
+                    refreshTokenSeenByGenerate = input.OAuthRefreshToken;
+                    return new GitCredential(userName, password) {
+                        OAuthRefreshToken = refreshToken,
+                    };
+                },
+            };
+
+            ICredential actualCredential = await ((IHostProvider) provider).GetCredentialAsync(input);
+
+            Assert.True(generateWasCalled);
+            Assert.Equal(storedRefreshToken, refreshTokenSeenByGenerate);
+            Assert.Equal(userName, actualCredential.Account);
+            Assert.Equal(password, actualCredential.Password);
+            Assert.Equal(refreshToken, actualCredential.OAuthRefreshToken);
+            // Invalid credential should be erased
+            Assert.Equal(0, context.CredentialStore.Count);
+        }
+
 
             #endregion
 
@@ -252,6 +297,18 @@ public async Task HostProvider_EraseCredentialAsync_DifferentHost_DoesNothing()
             Assert.True(context.CredentialStore.Contains(service3, userName));
         }
 
+        [Fact]
+        public void HostProvider_ValidateCredentialAsync()
+        {
+            var context = new TestCommandContext();
+            var provider = new TestHostProvider(context);
+            Assert.True(provider.ValidateCredentialAsync(null, new GitCredential("username", "pass")).Result);
+            Assert.True(provider.ValidateCredentialAsync(null, new GitCredential("username", "pass") {PasswordExpiry
+             = DateTimeOffset.UtcNow + TimeSpan.FromHours(1)}).Result);
+            Assert.False(provider.ValidateCredentialAsync(null, new GitCredential("username", "pass") {PasswordExpiry
+             = DateTimeOffset.UtcNow - TimeSpan.FromMinutes(1)}).Result);
+        }
+
         #endregion
     }
 }

src/shared/Core.Tests/Interop/Linux/SecretServiceCollectionTests.cs

@@ -17,18 +17,22 @@ public void SecretServiceCollection_ReadWriteDelete()
             string service = $"https://example.com/{Guid.NewGuid():N}";
             const string userName = "john.doe";
             const string password = "letmein123"; // [SuppressMessage("Microsoft.Security", "CS001:SecretInline", Justification="Fake credential")]
+            const string testRefreshToken = "xyzzy";
+            DateTimeOffset testExpiry = DateTimeOffset.FromUnixTimeSeconds(1919539847);
 
             try
             {
                 // Write
-                collection.AddOrUpdate(service, userName, password);
+                collection.AddOrUpdate(service, new GitCredential(userName, password) { PasswordExpiry = testExpiry, OAuthRefreshToken = testRefreshToken});
 
                 // Read
                 ICredential outCredential = collection.Get(service, userName);
 
                 Assert.NotNull(outCredential);
                 Assert.Equal(userName, userName);
                 Assert.Equal(password, outCredential.Password);
+                Assert.Equal(testRefreshToken, outCredential.OAuthRefreshToken);
+                Assert.Equal(testExpiry, outCredential.PasswordExpiry);
             }
             finally
             {

src/shared/Core.Tests/Interop/Windows/WindowsCredentialManagerTests.cs

@@ -19,13 +19,14 @@ public void WindowsCredentialManager_ReadWriteDelete()
             string service = $"https://example.com/{uniqueGuid}";
             const string userName = "john.doe";
             const string password = "letmein123"; // [SuppressMessage("Microsoft.Security", "CS001:SecretInline", Justification="Fake credential")]
+            const string testRefreshToken = "xyzzy";
 
             string expectedTargetName = $"{TestNamespace}:https://example.com/{uniqueGuid}";
 
             try
             {
                 // Write
-                credManager.AddOrUpdate(service, userName, password);
+                credManager.AddOrUpdate(service, new GitCredential(userName, password) { OAuthRefreshToken = testRefreshToken});
 
                 // Read
                 ICredential cred = credManager.Get(service, userName);
@@ -37,6 +38,7 @@ public void WindowsCredentialManager_ReadWriteDelete()
                 Assert.Equal(password, winCred.Password);
                 Assert.Equal(service, winCred.Service);
                 Assert.Equal(expectedTargetName, winCred.TargetName);
+                Assert.Equal(testRefreshToken, winCred.OAuthRefreshToken);
             }
             finally
             {

src/shared/Core/Commands/GetCommand.cs

@@ -35,9 +35,13 @@ protected override async Task ExecuteInternalAsync(InputArguments input, IHostPr
             // Return the credential to Git
             output["username"] = credential.Account;
             output["password"] = credential.Password;
+            if (credential.PasswordExpiry.HasValue)
+                output["password_expiry_utc"] = credential.PasswordExpiry.Value.ToUnixTimeSeconds().ToString();
+            if (!string.IsNullOrEmpty(credential.OAuthRefreshToken))
+                output["oauth_refresh_token"] = credential.OAuthRefreshToken;
 
             Context.Trace.WriteLine("Writing credentials to output:");
-            Context.Trace.WriteDictionarySecrets(output, new []{ "password" }, StringComparer.OrdinalIgnoreCase);
+            Context.Trace.WriteDictionarySecrets(output, new []{ "password", "oauth_refresh_token" }, StringComparer.OrdinalIgnoreCase);
 
             // Write the values to standard out
             Context.Streams.Out.WriteDictionary(output);

src/shared/Core/Commands/GitCommandBase.cs

@@ -44,7 +44,7 @@ internal async Task ExecuteAsync()
 
             // Determine the host provider
             Context.Trace.WriteLine("Detecting host provider for input:");
-            Context.Trace.WriteDictionarySecrets(inputDict, new []{ "password" }, StringComparer.OrdinalIgnoreCase);
+            Context.Trace.WriteDictionarySecrets(inputDict, new []{ "password", "oauth_refresh_token" }, StringComparer.OrdinalIgnoreCase);
             IHostProvider provider = await _hostProviderRegistry.GetProviderAsync(input);
             Context.Trace.WriteLine($"Host provider '{provider.Name}' was selected.");
 

src/shared/Core/Credential.cs

@@ -1,4 +1,7 @@
 
+using System;
+using GitCredentialManager.Authentication.OAuth;
+
 namespace GitCredentialManager
 {
     /// <summary>
@@ -15,21 +18,57 @@ public interface ICredential
         /// Password.
         /// </summary>
         string Password { get; }
+
+        /// <summary>
+        /// The expiry date of the password. This is Git's password_expiry_utc
+        /// attribute. https://git-scm.com/docs/git-credential#Documentation/git-credential.txt-codepasswordexpiryutccode
+        /// </summary>
+        DateTimeOffset? PasswordExpiry { get => null; }
+
+        /// <summary>
+        /// An OAuth refresh token. This is Git's oauth_refresh_token
+        /// attribute. https://git-scm.com/docs/git-credential#Documentation/git-credential.txt-codeoauthrefreshtokencode
+        /// </summary>
+        string OAuthRefreshToken { get => null; }
     }
 
     /// <summary>
     /// Represents a credential (username/password pair) that Git can use to authenticate to a remote repository.
     /// </summary>
-    public class GitCredential : ICredential
+    public record GitCredential : ICredential
     {
         public GitCredential(string userName, string password)
         {
             Account = userName;
             Password = password;
         }
 
-        public string Account { get; }
+        public GitCredential(InputArguments input)
+        {
+            Account = input.UserName;
+            Password = input.Password;
+            OAuthRefreshToken = input.OAuthRefreshToken;
+            if (long.TryParse(input.PasswordExpiry, out long x)) {
+                PasswordExpiry = DateTimeOffset.FromUnixTimeSeconds(x);
+            }
+        }
+
+        public GitCredential(OAuth2TokenResult tokenResult, string userName)
+        {
+            Account = userName;
+            Password = tokenResult.AccessToken;
+            OAuthRefreshToken = tokenResult.RefreshToken;
+            if (tokenResult.ExpiresIn.HasValue) {
+                PasswordExpiry = DateTimeOffset.UtcNow + tokenResult.ExpiresIn.Value;
+            }
+        }
+
+        public string Account { get; init; }
+
+        public string Password { get; init; }
 
-        public string Password { get; }
+        public DateTimeOffset? PasswordExpiry { get; init; }
+
+        public string OAuthRefreshToken { get; init; }
     }
 }