Add a way to get all values of an attribute of DN.

This is needed to switch Apache HTTP hostname verification from its
own Distinguished Name (DN) parsing code to this library's
DistinguishedNameParser.

Bug: 16510257
Change-Id: Iedd27cec162167dad11a4fe477d4eaa3eba004b7

2 files changed, 102 insertions, 20 deletions

diff --git a/luni/src/main/java/javax/net/ssl/DistinguishedNameParser.java b/luni/src/main/java/javax/net/ssl/DistinguishedNameParser.java
index c3c1606..25ab76f 100644
--- a/luni/src/main/java/javax/net/ssl/DistinguishedNameParser.java
+++ b/luni/src/main/java/javax/net/ssl/DistinguishedNameParser.java
@@ -17,6 +17,9 @@
 
 package javax.net.ssl;
 
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.List;
 import javax.security.auth.x500.X500Principal;
 
 /**
@@ -406,4 +409,71 @@ public final class DistinguishedNameParser {
             }
         }
     }
+
+    /**
+     * Parses the DN and returns all values for an attribute type, in
+     * the order of decreasing significance (most significant first).
+     *
+     * @param attributeType attribute type to look for (e.g. "ca")
+     */
+    public List<String> getAllMostSpecificFirst(String attributeType) {
+        // Initialize internal state.
+        pos = 0;
+        beg = 0;
+        end = 0;
+        cur = 0;
+        chars = dn.toCharArray();
+        List<String> result = Collections.emptyList();
+
+        String attType = nextAT();
+        if (attType == null) {
+            return result;
+        }
+        while (pos < length) {
+            String attValue = "";
+
+            switch (chars[pos]) {
+            case '"':
+                attValue = quotedAV();
+                break;
+            case '#':
+                attValue = hexAV();
+                break;
+            case '+':
+            case ',':
+            case ';': // compatibility with RFC 1779: semicolon can separate RDNs
+                //empty attribute value
+                break;
+            default:
+                attValue = escapedAV();
+            }
+
+            // Values are ordered from most specific to least specific
+            // due to the RFC2253 formatting. So take the first match
+            // we see.
+            if (attributeType.equalsIgnoreCase(attType)) {
+                if (result.isEmpty()) {
+                    result = new ArrayList<String>();
+                }
+                result.add(attValue);
+            }
+
+            if (pos >= length) {
+                break;
+            }
+
+            if (chars[pos] == ',' || chars[pos] == ';') {
+            } else if (chars[pos] != '+') {
+                throw new IllegalStateException("Malformed DN: " + dn);
+            }
+
+            pos++;
+            attType = nextAT();
+            if (attType == null) {
+                throw new IllegalStateException("Malformed DN: " + dn);
+            }
+        }
+
+        return result;
+    }
 }
diff --git a/luni/src/test/java/libcore/javax/net/ssl/DistinguishedNameParserTest.java b/luni/src/test/java/libcore/javax/net/ssl/DistinguishedNameParserTest.java
index 723c697..91c596f 100644
--- a/luni/src/test/java/libcore/javax/net/ssl/DistinguishedNameParserTest.java
+++ b/luni/src/test/java/libcore/javax/net/ssl/DistinguishedNameParserTest.java
@@ -19,38 +19,50 @@ package libcore.javax.net.ssl;
 import javax.net.ssl.DistinguishedNameParser;
 import javax.security.auth.x500.X500Principal;
 import junit.framework.TestCase;
+import java.util.Arrays;
 
 public final class DistinguishedNameParserTest extends TestCase {
-    public void testGetFirstCn() {
-        assertFirstCn("", null);
-        assertFirstCn("ou=xxx", null);
-        assertFirstCn("ou=xxx,cn=xxx", "xxx");
-        assertFirstCn("ou=xxx+cn=yyy,cn=zzz+cn=abc", "yyy");
-        assertFirstCn("cn=a,cn=b", "a");
-        assertFirstCn("cn=Cc,cn=Bb,cn=Aa", "Cc");
-        assertFirstCn("cn=imap.gmail.com", "imap.gmail.com");
+    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=Cc,cn=Bb,cn=Aa", "Cc", "Bb", "Aa");
+        assertCns("cn=imap.gmail.com", "imap.gmail.com");
+        assertCns("l=\"abcn=a,b\", cn=c", "c");
     }
 
-    public void testGetFirstCnWithOid() {
-        assertFirstCn("2.5.4.3=a,ou=xxx", "a");
+    public void testGetCnsWithOid() {
+        assertCns("2.5.4.3=a,ou=xxx", "a");
     }
 
-    public void testGetFirstCnWithQuotedStrings() {
-        assertFirstCn("cn=\"\\\" a ,=<>#;\"", "\" a ,=<>#;");
-        assertFirstCn("cn=abc\\,def", "abc,def");
+    public void testGetCnsWithQuotedStrings() {
+        assertCns("cn=\"\\\" a ,=<>#;\"", "\" a ,=<>#;");
+        assertCns("cn=abc\\,def", "abc,def");
     }
 
-    public void testGetFirstCnWithUtf8() {
-        assertFirstCn("cn=Lu\\C4\\8Di\\C4\\87", "\u004c\u0075\u010d\u0069\u0107");
+    public void testGetCnsWithUtf8() {
+        assertCns("cn=Lu\\C4\\8Di\\C4\\87", "\u004c\u0075\u010d\u0069\u0107");
     }
 
-    public void testGetFirstCnWithWhitespace() {
-        assertFirstCn("ou=a, cn=  a  b  ,o=x", "a  b");
-        assertFirstCn("cn=\"  a  b  \" ,o=x", "  a  b  ");
+    public void testGetCnsWithWhitespace() {
+        assertCns("ou=a, cn=  a  b  ,o=x", "a  b");
+        assertCns("cn=\"  a  b  \" ,o=x", "  a  b  ");
     }
 
-    private void assertFirstCn(String dn, String expected) {
+    private void assertCns(String dn, String... expected) {
         X500Principal principal = new X500Principal(dn);
-        assertEquals(dn, expected, new DistinguishedNameParser(principal).findMostSpecific("cn"));
+        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"));
+        }
     }
 }