Use a callback for credentials

Instead of making the user choose beforehand, use a callback to let the
user ask a database or human about the credentials.

If desired, a hard-coded value can still be provided via a lambda, e.g.

    (_url, _user, _types) => new UsernamePasswordCredentials() { ... }

Author: carlosmn

LibGit2Sharp.Tests/CloneFixture.cs

@@ -151,7 +151,7 @@ public void CanCloneWithCredentials()
             string clonedRepoPath = Repository.Clone(Constants.PrivateRepoUrl, scd.DirectoryPath,
                 new CloneOptions()
                 {
-                    Credentials = Constants.PrivateRepoCredentials
+                    CredentialsProvider = (_url, _user, _cred) => Constants.PrivateRepoCredentials
                 });
 
 

LibGit2Sharp.Tests/FetchFixture.cs

@@ -60,7 +60,7 @@ public void CanFetchIntoAnEmptyRepositoryWithCredentials()
                 // Perform the actual fetch
                 repo.Network.Fetch(remote, new FetchOptions
                 {
-                    Credentials = Constants.PrivateRepoCredentials
+                    CredentialsProvider = (_url, _user, _credtype) => Constants.PrivateRepoCredentials
                 });
             }
         }

LibGit2Sharp.Tests/NetworkFixture.cs

@@ -121,7 +121,7 @@ public void CanListRemoteReferencesWithCredentials()
             {
                 Remote remote = repo.Network.Remotes.Add(remoteName, Constants.PrivateRepoUrl);
 
-                var references = repo.Network.ListReferences(remote, Constants.PrivateRepoCredentials);
+                var references = repo.Network.ListReferences(remote, (_url, _user, _credtype) => Constants.PrivateRepoCredentials);
 
                 foreach (var directReference in references)
                 {

LibGit2Sharp/CloneOptions.cs

@@ -1,4 +1,5 @@
-using LibGit2Sharp.Core;
+using System;
+using LibGit2Sharp.Core;
 using LibGit2Sharp.Handlers;
 
 namespace LibGit2Sharp
@@ -40,7 +41,7 @@ public CloneOptions()
         /// <summary>
         /// Credentials to use for user/pass authentication
         /// </summary>
-        public Credentials Credentials { get; set; }
+        public CredentialsHandler CredentialsProvider { get; set; }
 
         #region IConvertableToGitCheckoutOpts
 

LibGit2Sharp/FetchOptions.cs

@@ -1,4 +1,5 @@
-using LibGit2Sharp.Handlers;
+using System;
+using LibGit2Sharp.Handlers;
 
 namespace LibGit2Sharp
 {
@@ -41,6 +42,6 @@ public sealed class FetchOptions
         /// <summary>
         /// Credentials to use for username/password authentication.
         /// </summary>
-        public Credentials Credentials { get; set; }
+        public CredentialsHandler CredentialsProvider { get; set; }
     }
 }

LibGit2Sharp/Handlers.cs

@@ -22,6 +22,14 @@
     /// <returns>True to continue, false to cancel.</returns>
     public delegate bool UpdateTipsHandler(string referenceName, ObjectId oldId, ObjectId newId);
 
+    /// <summary>
+    /// Delegate definition for the credentials retrieval callback
+    /// </summary>
+    /// <param name="usernameFromUrl">Username which was extracted form the url, if any</param>
+    /// <param name="url">The url</param>
+    /// <param name="types">Credential types which the server accepts</param>
+    public delegate Credentials CredentialsHandler(string url, string usernameFromUrl, SupportedCredentialTypes types);
+
     /// <summary>
     /// Delegate definition for transfer progress callback.
     /// </summary>

LibGit2Sharp/LibGit2Sharp.csproj

@@ -317,6 +317,7 @@
     <Compile Include="VoidReference.cs" />
     <Compile Include="Core\RawContentStream.cs" />
     <Compile Include="Core\Handles\OdbStreamSafeHandle.cs" />
+    <Compile Include="SupportedCredentialTypes.cs" />
   </ItemGroup>
   <ItemGroup>
     <CodeAnalysisDictionary Include="CustomDictionary.xml" />

LibGit2Sharp/Network.cs

@@ -46,17 +46,17 @@ public virtual RemoteCollection Remotes
         /// </para>
         /// </summary>
         /// <param name="remote">The <see cref="Remote"/> to list from.</param>
-        /// <param name="credentials">The optional <see cref="Credentials"/> used to connect to remote repository.</param>
+        /// <param name="credentials">The optional <see cref="Func<Credentials>"/> used to connect to remote repository.</param>
         /// <returns>The references in the <see cref="Remote"/> repository.</returns>
-        public virtual IEnumerable<DirectReference> ListReferences(Remote remote, Credentials credentials = null)
+        public virtual IEnumerable<DirectReference> ListReferences(Remote remote, CredentialsHandler credentialsProvider = null)
         {
             Ensure.ArgumentNotNull(remote, "remote");
 
             using (RemoteSafeHandle remoteHandle = Proxy.git_remote_load(repository.Handle, remote.Name, true))
             {
-                if (credentials != null)
+                if (credentialsProvider != null)
                 {
-                    var callbacks = new RemoteCallbacks(null, null, null, credentials);
+                    var callbacks = new RemoteCallbacks(null, null, null, credentialsProvider);
                     GitRemoteCallbacks gitCallbacks = callbacks.GenerateCallbacks();
                     Proxy.git_remote_set_callbacks(remoteHandle, ref gitCallbacks);
                 }
@@ -272,7 +272,7 @@ public virtual void Push(
             // Load the remote.
             using (RemoteSafeHandle remoteHandle = Proxy.git_remote_load(repository.Handle, remote.Name, true))
             {
-                var callbacks = new RemoteCallbacks(null, null, null, pushOptions.Credentials);
+                var callbacks = new RemoteCallbacks(null, null, null, pushOptions.CredentialsProvider);
                 GitRemoteCallbacks gitCallbacks = callbacks.GenerateCallbacks();
                 Proxy.git_remote_set_callbacks(remoteHandle, ref gitCallbacks);
 

LibGit2Sharp/PushOptions.cs

@@ -1,4 +1,5 @@
-using LibGit2Sharp.Handlers;
+using System;
+using LibGit2Sharp.Handlers;
 
 namespace LibGit2Sharp
 {
@@ -10,7 +11,7 @@ public sealed class PushOptions
         /// <summary>
         /// The <see cref="Credentials"/> to authenticate with during the push.
         /// </summary>
-        public Credentials Credentials { get; set; }
+        public CredentialsHandler CredentialsProvider { get; set; }
 
         /// <summary>
         /// If the transport being used to push to the remote requires the creation

LibGit2Sharp/RemoteCallbacks.cs

@@ -16,12 +16,12 @@ internal RemoteCallbacks(
             ProgressHandler onProgress = null,
             TransferProgressHandler onDownloadProgress = null,
             UpdateTipsHandler onUpdateTips = null,
-            Credentials credentials = null)
+            CredentialsHandler credentialsProvider = null)
         {
             Progress = onProgress;
             DownloadTransferProgress = onDownloadProgress;
             UpdateTips = onUpdateTips;
-            Credentials = credentials;
+            CredentialsProvider = credentialsProvider;
         }
 
         internal RemoteCallbacks(FetchOptions fetchOptions)
@@ -30,7 +30,7 @@ internal RemoteCallbacks(FetchOptions fetchOptions)
             Progress = fetchOptions.OnProgress;
             DownloadTransferProgress = fetchOptions.OnTransferProgress;
             UpdateTips = fetchOptions.OnUpdateTips;
-            Credentials = fetchOptions.Credentials;
+            CredentialsProvider = fetchOptions.CredentialsProvider;
         }
 
         #region Delegates
@@ -54,9 +54,9 @@ internal RemoteCallbacks(FetchOptions fetchOptions)
         #endregion
 
         /// <summary>
-        /// The credentials to use for the credential callback.
+        /// The credentials to use for authentication.
         /// </summary>
-        Credentials Credentials;
+        private readonly CredentialsHandler CredentialsProvider;
 
         internal GitRemoteCallbacks GenerateCallbacks()
         {
@@ -72,9 +72,9 @@ internal GitRemoteCallbacks GenerateCallbacks()
                 callbacks.update_tips = GitUpdateTipsHandler;
             }
 
-            if (Credentials != null)
+            if (CredentialsProvider != null)
             {
-                callbacks.acquire_credentials = Credentials.GitCredentialHandler;
+                callbacks.acquire_credentials = GitCredentialHandler;
             }
 
             if (DownloadTransferProgress != null)
@@ -153,6 +153,26 @@ private int GitDownloadTransferProgressHandler(ref GitTransferProgress progress,
             return Proxy.ConvertResultToCancelFlag(shouldContinue);
         }
 
+        private int GitCredentialHandler(out IntPtr ptr, IntPtr cUrl, IntPtr usernameFromUrl, GitCredentialType credTypes, IntPtr payload)
+        {
+            string url = LaxUtf8Marshaler.FromNative(cUrl);
+            string username = LaxUtf8Marshaler.FromNative(usernameFromUrl);
+
+            SupportedCredentialTypes types = default(SupportedCredentialTypes);
+            if (credTypes.HasFlag(GitCredentialType.UserPassPlaintext))
+            {
+                types |= SupportedCredentialTypes.UsernamePassword;
+            }
+            if (credTypes.HasFlag(GitCredentialType.Default))
+            {
+                types |= SupportedCredentialTypes.Default;
+            }
+
+            var cred = CredentialsProvider(url, username, types);
+
+            return cred.GitCredentialHandler(out ptr, cUrl, usernameFromUrl, credTypes, payload);
+        }
+
         #endregion
     }
 }

LibGit2Sharp/Repository.cs

@@ -545,7 +545,7 @@ public static string Clone(string sourceUrl, string workdirPath,
             {
                 var gitCheckoutOptions = checkoutOptionsWrapper.Options;
 
-                var remoteCallbacks = new RemoteCallbacks(null, options.OnTransferProgress, null, options.Credentials);
+                var remoteCallbacks = new RemoteCallbacks(null, options.OnTransferProgress, null, options.CredentialsProvider);
                 var gitRemoteCallbacks = remoteCallbacks.GenerateCallbacks();
 
                 var cloneOpts = new GitCloneOptions

LibGit2Sharp/SupportedCredentialTypes.cs

@@ -0,0 +1,22 @@
+using System;
+
+namespace LibGit2Sharp
+{
+    /// <summary>
+    /// Credential types supported by the server. If the server supports a particular type of
+    /// authentication, it will be set to true.
+    /// </summary>
+    [Flags]
+    public enum SupportedCredentialTypes
+    {
+        /// <summary>
+        /// Plain username and password combination
+        /// </summary>
+        UsernamePassword = (1 << 0),
+
+        /// <summary>
+        /// Ask Windows to provide its default credentials for the current user (e.g. NTLM)
+        /// </summary>
+        Default = (1 << 1),
+    }
+}