diff --git a/okhttp-tests/src/test/java/okhttp3/internal/tls/DistinguishedNameParserTest.java b/okhttp-tests/src/test/java/okhttp3/internal/tls/DistinguishedNameParserTest.java
new file mode 100644
index 000000000000..8d46177a2b06
--- /dev/null
+++ b/okhttp-tests/src/test/java/okhttp3/internal/tls/DistinguishedNameParserTest.java
@@ -0,0 +1,160 @@
+/*
+ * Copyright (C) 2010 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package okhttp3.internal.tls;
+
+
+import javax.security.auth.x500.X500Principal;
+
+import org.junit.Test;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNull;
+import static org.junit.Assert.fail;
+
+public final class DistinguishedNameParserTest {
+  @Test public void testGetCns() {
+    assertCns("");
+    assertCns("ou=xxx");
+    assertCns("ou=xxx,cn=xxx", "xxx");
+    assertCns("ou=xxx+cn=yyy,cn=zzz+cn=abc", "yyy", "zzz", "abc");
+    assertCns("cn=a,cn=b", "a", "b");
+    assertCns("cn=a   c,cn=b", "a   c", "b");
+    assertCns("cn=a   ,cn=b", "a", "b");
+    assertCns("cn=Cc,cn=Bb,cn=Aa", "Cc", "Bb", "Aa");
+    assertCns("cn=imap.gmail.com", "imap.gmail.com");
+    assertCns("l=\"abcn=a,b\", cn=c", "c");
+    assertCns("l=\"abcn=a,b\", cn=c", "c");
+    assertCns("l=\"abcn=a,b\", cn= c", "c");
+    assertCns("cn=<", "<");
+    assertCns("cn=>", ">");
+    assertCns("cn= >", ">");
+    assertCns("cn=a b", "a b");
+    assertCns("cn   =a b", "a b");
+    assertCns("Cn=a b", "a b");
+    assertCns("cN=a b", "a b");
+    assertCns("CN=a b", "a b");
+    assertCns("cn=a#b", "a#b");
+    assertCns("cn=#130161", "a");
+    assertCns("l=q\t+cn=p", "p");
+    assertCns("l=q\n+cn=p", "p");
+    assertCns("l=q\n,cn=p", "p");
+    assertCns("l=,cn=p", "p");
+    assertCns("l=\tq\n,cn=\tp", "\tp");
+  }
+
+  /** A cn=, generates an empty value, unless it's at the very end. */
+  @Test public void emptyValues() {
+    assertCns("l=,cn=+cn=q", "", "q");
+    assertCns("l=,cn=,cn=q", "", "q");
+    assertCns("l=,cn=");
+    assertCns("l=,cn=q,cn=   ", "q");
+    assertCns("l=,cn=q  ,cn=   ", "q");
+    assertCns("l=,cn=\"\"");
+    assertCns("l=,cn=\"  \",cn=\"  \"","  ");
+    assertCns("l=,cn=  ,cn=  ","");
+    assertCns("l=,cn=,cn=  ,cn=  ", "", "");
+  }
+
+
+  @Test public void testGetCns_escapedChars() {
+    assertCns("cn=\\,", ",");
+    assertCns("cn=\\#", "#");
+    assertCns("cn=\\+", "+");
+    assertCns("cn=\\\"", "\"");
+    assertCns("cn=\\\\", "\\");
+    assertCns("cn=\\<", "<");
+    assertCns("cn=\\>", ">");
+    assertCns("cn=\\;", ";");
+    assertCns("cn=\\+", "+");
+    assertCns("cn=\"\\+\"", "+");
+    assertCns("cn=\"\\,\"", ",");
+    assertCns("cn= a =", "a =");
+    assertCns("cn==", "=");
+  }
+
+  @Test public void testGetCns_whitespace() {
+    assertCns("cn= p", "p");
+    assertCns("cn=\np", "\np");
+    assertCns("cn=\tp", "\tp");
+  }
+
+  @Test public void testGetCnsWithOid() {
+    assertCns("2.5.4.3=a,ou=xxx", "a");
+    assertCns("2.5.4.3=\" a \",ou=xxx", " a ");
+    assertCns("2.5.5.3=a,ou=xxx,cn=b", "b");
+  }
+
+  @Test public void testGetCnsWithQuotedStrings() {
+    assertCns("cn=\"\\\" a ,=<>#;\"", "\" a ,=<>#;");
+    assertCns("cn=abc\\,def", "abc,def");
+    assertCns("cn=\"\\\" a ,\\=<>\\#;\"", "\" a ,=<>#;");
+  }
+
+  @Test public void testGetCnsWithUtf8() {
+    assertCns("cn=\"Lu\\C4\\8Di\\C4\\87\"", "\u004c\u0075\u010d\u0069\u0107");
+    assertCns("cn=Lu\\C4\\8Di\\C4\\87", "\u004c\u0075\u010d\u0069\u0107");
+    assertCns("cn=Lu\\C4\\8di\\c4\\87", "\u004c\u0075\u010d\u0069\u0107");
+    assertCns("cn=\"Lu\\C4\\8di\\c4\\87\"", "\u004c\u0075\u010d\u0069\u0107");
+    assertCns("cn=\u004c\u0075\u010d\u0069\u0107", "\u004c\u0075\u010d\u0069\u0107");
+    // \63=c
+    expectExceptionInPrincipal("\\63n=ab");
+    expectExceptionInPrincipal("cn=\\a");
+  }
+
+  @Test public void testGetCnsWithWhitespace() {
+
+    assertCns("ou=a, cn=  a  b  ,o=x", "a  b");
+    assertCns("cn=\"  a  b  \" ,o=x", "  a  b  ");
+  }
+
+  private void assertCns(String dn, String... expected) {
+    X500Principal principal = new X500Principal(dn);
+    DistinguishedNameParser parser = new DistinguishedNameParser(principal);
+    // Test getAllMostSpecificFirst
+//        assertEquals(dn, Arrays.asList(expected), parser.getAllMostSpecificFirst("cn"));
+
+    // Test findMostSpecific
+    if (expected.length > 0) {
+      assertEquals(dn, expected[0], parser.findMostSpecific("cn"));
+    } else {
+      assertNull(dn, parser.findMostSpecific("cn"));
+    }
+  }
+
+  private void assertGetAttribute(String dn, String attribute, String... expected) {
+    X500Principal principal = new X500Principal(dn);
+    DistinguishedNameParser parser = new DistinguishedNameParser(principal);
+    // Test getAllMostSpecificFirst
+//        assertEquals(dn, Arrays.asList(expected), parser.getAllMostSpecificFirst(attribute));
+
+    // Test findMostSpecific
+    if (expected.length > 0) {
+      assertEquals(dn, expected[0], parser.findMostSpecific(attribute));
+    } else {
+      assertNull(dn, parser.findMostSpecific(attribute));
+    }
+  }
+
+  private void expectExceptionInPrincipal(String dn) {
+    try {
+      X500Principal principal = new X500Principal(dn);
+      fail("Expected " + IllegalArgumentException.class.getName()
+          + " because of incorrect input name");
+    } catch (IllegalArgumentException e) {
+      // Expected.
+    }
+  }
+}