http transport does not use authentication fallback

Git servers supporting HTTP transport can send multiple WWW-Authenticate
challenges [1] for different authentication schemes the server supports.
If authentication fails now retry all authentication types proposed by
the server.

[1] https://tools.ietf.org/html/rfc2617#page-3

Bug: 492057
Change-Id: I01d438a5896f9b1008bd6b751ad9c7cbf780af1a
Signed-off-by: Christian Pontesegger <christian.pontesegger@web.de>
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>

org.eclipse.jgit.test/tst/org/eclipse/jgit/transport/HttpAuthTest.java

@@ -100,7 +100,7 @@ public class HttpAuthTest {
 		} catch (IOException e) {
 			fail("Couldn't instantiate AuthHeadersResponse: " + e.toString());
 		}
-		HttpAuthMethod authMethod = HttpAuthMethod.scanResponse(response);
+		HttpAuthMethod authMethod = HttpAuthMethod.scanResponse(response, null);
 
 		if (!expectedAuthMethod.equals(getAuthMethodName(authMethod))) {
 			fail("Wrong authentication method: expected " + expectedAuthMethod

org.eclipse.jgit/src/org/eclipse/jgit/transport/HttpAuthMethod.java

@@ -51,6 +51,7 @@ import java.io.UnsupportedEncodingException;
 import java.net.URL;
 import java.security.MessageDigest;
 import java.security.NoSuchAlgorithmException;
+import java.util.Collection;
 import java.util.Collections;
 import java.util.HashMap;
 import java.util.LinkedHashMap;
@@ -149,9 +150,12 @@ abstract class HttpAuthMethod {
 	 *
 	 * @param conn
 	 *            the connection that failed.
+	 * @param ignoreTypes
+	 *            authentication types to be ignored.
 	 * @return new authentication method to try.
 	 */
-	static HttpAuthMethod scanResponse(final HttpConnection conn) {
+	static HttpAuthMethod scanResponse(final HttpConnection conn,
+			Collection<Type> ignoreTypes) {
 		final Map<String, List<String>> headers = conn.getHeaderFields();
 		HttpAuthMethod authentication = Type.NONE.method(EMPTY_STRING);
 
@@ -165,6 +169,12 @@ abstract class HttpAuthMethod {
 
 							try {
 								Type methodType = Type.valueOf(valuePart[0].toUpperCase());
+
+								if ((ignoreTypes != null)
+										&& (ignoreTypes.contains(methodType))) {
+									continue;
+								}
+
 								if (authentication.getType().compareTo(methodType) >= 0) {
 									continue;
 								}

org.eclipse.jgit/src/org/eclipse/jgit/transport/TransportHttp.java

@@ -73,6 +73,7 @@ import java.util.Arrays;
 import java.util.Collection;
 import java.util.Collections;
 import java.util.EnumSet;
+import java.util.HashSet;
 import java.util.LinkedHashSet;
 import java.util.Map;
 import java.util.Set;
@@ -95,6 +96,7 @@ import org.eclipse.jgit.lib.ProgressMonitor;
 import org.eclipse.jgit.lib.Ref;
 import org.eclipse.jgit.lib.Repository;
 import org.eclipse.jgit.lib.SymbolicRef;
+import org.eclipse.jgit.transport.HttpAuthMethod.Type;
 import org.eclipse.jgit.transport.http.HttpConnection;
 import org.eclipse.jgit.util.HttpSupport;
 import org.eclipse.jgit.util.IO;
@@ -448,9 +450,11 @@ public class TransportHttp extends HttpTransport implements WalkTransport,
 			throw new NotSupportedException(MessageFormat.format(JGitText.get().invalidURL, uri), e);
 		}
 
-		try {
+
 		int authAttempts = 1;
+		Collection<Type> ignoreTypes = null;
 		for (;;) {
+			try {
 				final HttpConnection conn = httpOpen(u);
 				if (useSmartHttp) {
 					String exp = "application/x-" + service + "-advertisement"; //$NON-NLS-1$ //$NON-NLS-2$
@@ -467,7 +471,7 @@ public class TransportHttp extends HttpTransport implements WalkTransport,
 					// explicit authentication would be required
 					if (authMethod.getType() == HttpAuthMethod.Type.NONE
 							&& conn.getHeaderField(HDR_WWW_AUTHENTICATE) != null)
-						authMethod = HttpAuthMethod.scanResponse(conn);
+						authMethod = HttpAuthMethod.scanResponse(conn, ignoreTypes);
 					return conn;
 
 				case HttpConnection.HTTP_NOT_FOUND:
@@ -475,7 +479,7 @@ public class TransportHttp extends HttpTransport implements WalkTransport,
 							MessageFormat.format(JGitText.get().uriNotFound, u));
 
 				case HttpConnection.HTTP_UNAUTHORIZED:
-					authMethod = HttpAuthMethod.scanResponse(conn);
+					authMethod = HttpAuthMethod.scanResponse(conn, ignoreTypes);
 					if (authMethod.getType() == HttpAuthMethod.Type.NONE)
 						throw new TransportException(uri, MessageFormat.format(
 								JGitText.get().authenticationNotSupported, uri));
@@ -501,15 +505,29 @@ public class TransportHttp extends HttpTransport implements WalkTransport,
 					String err = status + " " + conn.getResponseMessage(); //$NON-NLS-1$
 					throw new TransportException(uri, err);
 				}
-			}
 			} catch (NotSupportedException e) {
 				throw e;
 			} catch (TransportException e) {
 				throw e;
 			} catch (IOException e) {
+				if (authMethod.getType() != HttpAuthMethod.Type.NONE) {
+					if (ignoreTypes == null) {
+						ignoreTypes = new HashSet<Type>();
+					}
+
+					ignoreTypes.add(authMethod.getType());
+
+					// reset auth method & attempts for next authentication type
+					authMethod = HttpAuthMethod.Type.NONE.method(null);
+					authAttempts = 1;
+
+					continue;
+				}
+
 				throw new TransportException(uri, MessageFormat.format(JGitText.get().cannotOpenService, service), e);
 			}
 		}
+	}
 
 	final HttpConnection httpOpen(URL u) throws IOException {
 		return httpOpen(METHOD_GET, u);