Backport old digest auth to 1.7

Prior patch added old style digest auth to 1.8. Need to get this
backported to 1.7

Author: taer

src/main/java/com/ning/http/client/Realm.java

@@ -526,12 +526,23 @@ private void newResponse() throws UnsupportedEncodingException {
             byte[] ha1 = md.digest();
 
             md.reset();
+
+            //HA2 if qop is auth-int is methodName:url:md5(entityBody)
             md.update(new StringBuilder(methodName)
                     .append(':')
                     .append(uri).toString().getBytes("ISO-8859-1"));
             byte[] ha2 = md.digest();
 
-            md.update(new StringBuilder(toBase16(ha1))
+            if(qop==null || qop.equals("")) {
+                 md.update(new StringBuilder(toBase16(ha1))
+                    .append(':')
+                    .append(nonce)
+                    .append(':')
+                    .append(toBase16(ha2)).toString().getBytes("ISO-8859-1"));
+
+             } else {
+                 //qop ="auth" or "auth-int"
+                 md.update(new StringBuilder(toBase16(ha1))
                     .append(':')
                     .append(nonce)
                     .append(':')
@@ -542,6 +553,8 @@ private void newResponse() throws UnsupportedEncodingException {
                     .append(qop)
                     .append(':')
                     .append(toBase16(ha2)).toString().getBytes("ISO-8859-1"));
+            }
+
             byte[] digest = md.digest();
 
             response = toHexString(digest);

src/test/java/com/ning/http/client/RealmTest.java

@@ -15,6 +15,9 @@
 import com.ning.http.client.Realm.AuthScheme;
 import com.ning.http.client.Realm.RealmBuilder;
 import org.testng.Assert;
+import java.math.BigInteger;
+import java.security.MessageDigest;
+import java.security.NoSuchAlgorithmException;
 import org.testng.annotations.Test;
 
 public class RealmTest {
@@ -36,4 +39,82 @@ public void testClone() {
         Assert.assertEquals( clone.getAlgorithm(), orig.getAlgorithm() );
         Assert.assertEquals( clone.getAuthScheme(), orig.getAuthScheme() );
     }
+    @Test(groups = "fast")
+    public void testOldDigestEmptyString() {
+        String qop="";
+        testOldDigest(qop);
+    }
+    @Test(groups = "fast")
+    public void testOldDigestNull() {
+        String qop=null;
+        testOldDigest(qop);
+    }
+
+    private void testOldDigest(String qop){
+        String user="user";
+        String pass="pass";
+        String realm="realm";
+        String nonce="nonce";
+        String method="GET";
+        String uri="/foo";
+        RealmBuilder builder = new RealmBuilder();
+        builder.setPrincipal( user ).setPassword( pass );
+        builder.setNonce( nonce );
+        builder.setUri( uri );
+        builder.setMethodName(method);
+        builder.setRealmName( realm );
+        builder.setQop(qop);
+        builder.setScheme( AuthScheme.DIGEST );
+        Realm orig = builder.build();
+
+        String ha1=getMd5(user +":" + realm +":"+pass);
+        String ha2=getMd5(method +":"+ uri);
+        String expectedResponse=getMd5(ha1 +":" + nonce +":"  + ha2);
+
+        Assert.assertEquals(expectedResponse,orig.getResponse());
+    }
+
+    @Test(groups = "fast")
+    public void testStrongDigest() {
+        String user="user";
+        String pass="pass";
+        String realm="realm";
+        String nonce="nonce";
+        String method="GET";
+        String uri="/foo";
+        String qop="auth";
+        RealmBuilder builder = new RealmBuilder();
+        builder.setPrincipal( user ).setPassword( pass );
+        builder.setNonce( nonce );
+        builder.setUri( uri );
+        builder.setMethodName(method);
+        builder.setRealmName( realm );
+        builder.setQop(qop);
+        builder.setScheme( AuthScheme.DIGEST );
+        Realm orig = builder.build();
+
+        String nc = orig.getNc();
+        String cnonce = orig.getCnonce();
+        String ha1=getMd5(user +":" + realm +":"+pass);
+        String ha2=getMd5(method +":"+ uri);
+        String expectedResponse=getMd5(ha1 +":" + nonce +":" + nc + ":" + cnonce +":" + qop + ":" + ha2);
+
+        Assert.assertEquals(expectedResponse,orig.getResponse());
+    }
+
+    private String getMd5(String what){
+            try {
+            MessageDigest md = MessageDigest.getInstance("MD5");
+                md.update(what.getBytes("ISO-8859-1"));
+                byte[] hash  = md.digest();
+                BigInteger bi = new BigInteger(1, hash);
+                String result = bi.toString(16);
+                if (result.length() % 2 != 0) {
+                    return "0" + result;
+                }
+                return result;
+            } catch (Exception e) {
+                throw new RuntimeException(e);
+            }
+    }
 }