Added aliases for dnQualifier, relates to github #1622.

Author: dghgit

core/src/main/java/org/bouncycastle/asn1/x500/style/BCStyle.java

@@ -278,6 +278,8 @@ public class BCStyle
         DefaultLookUp.put("unstructuredname", UnstructuredName);
         DefaultLookUp.put("uniqueidentifier", UNIQUE_IDENTIFIER);
         DefaultLookUp.put("dn", DN_QUALIFIER);
+        DefaultLookUp.put("dnq", DN_QUALIFIER);
+        DefaultLookUp.put("dnqualifier", DN_QUALIFIER);
         DefaultLookUp.put("pseudonym", PSEUDONYM);
         DefaultLookUp.put("postaladdress", POSTAL_ADDRESS);
         DefaultLookUp.put("nameatbirth", NAME_AT_BIRTH);

core/src/main/java/org/bouncycastle/asn1/x500/style/RFC4519Style.java

@@ -122,6 +122,8 @@ public class RFC4519Style
         DefaultLookUp.put("destinationindicator", destinationIndicator);
         DefaultLookUp.put("distinguishedname", distinguishedName);
         DefaultLookUp.put("dnqualifier", dnQualifier);
+        DefaultLookUp.put("dn", dnQualifier);
+        DefaultLookUp.put("dnq", dnQualifier);
         DefaultLookUp.put("enhancedsearchguide", enhancedSearchGuide);
         DefaultLookUp.put("facsimiletelephonenumber", facsimileTelephoneNumber);
         DefaultLookUp.put("generationqualifier", generationQualifier);

core/src/test/java/org/bouncycastle/asn1/test/X500NameTest.java

@@ -23,6 +23,7 @@
 import org.bouncycastle.asn1.x500.style.BCStrictStyle;
 import org.bouncycastle.asn1.x500.style.BCStyle;
 import org.bouncycastle.asn1.x500.style.IETFUtils;
+import org.bouncycastle.asn1.x500.style.RFC4519Style;
 import org.bouncycastle.asn1.x509.X509DefaultEntryConverter;
 import org.bouncycastle.util.encoders.Hex;
 import org.bouncycastle.util.test.SimpleTest;
@@ -150,6 +151,7 @@ public void performTest()
     {
         ietfUtilsTest();
         bogusEqualsTest();
+        dnQualifierAliasParseTest();
 
         testEncodingPrintableString(BCStyle.C, "AU");
         testEncodingPrintableString(BCStyle.SERIALNUMBER, "123456");
@@ -682,6 +684,43 @@ private void ietfUtilsTest()
         IETFUtils.valueToString(new DERUTF8String(" "));
     }
 
+    /**
+     * BCStyle / RFC4519Style now accept "DN", "DNQ" and "dnQualifier"
+     * as parser aliases for the dnQualifier attribute (OID 2.5.4.46).
+     * The motivating case was that {@code java.security.cert.X509Certificate.getSubjectX500Principal().toString()}
+     * emits "DNQ=" on some JDKs (Amazon Corretto 17 observed) and
+     * "DNQUALIFIER=" on others, neither of which round-tripped through
+     * {@code new X500Name(principal.toString())} under BCStyle's
+     * historical "DN" form (issue #1622).
+     */
+    private void dnQualifierAliasParseTest()
+        throws Exception
+    {
+        String[] aliases = new String[]{ "DN", "DNQ", "dnQualifier", "dn", "dnq", "dnqualifier" };
+        for (int i = 0; i != aliases.length; ++i)
+        {
+            String alias = aliases[i];
+
+            X500Name viaBcStyle = new X500Name(BCStyle.INSTANCE,
+                "CN=Foo," + alias + "=ABC123");
+            RDN[] rdnsBc = viaBcStyle.getRDNs(BCStyle.DN_QUALIFIER);
+            if (rdnsBc.length != 1)
+            {
+                fail("BCStyle: alias '" + alias
+                    + "' did not parse to a single dnQualifier RDN");
+            }
+
+            X500Name viaRfc = new X500Name(RFC4519Style.INSTANCE,
+                "CN=Foo," + alias + "=ABC123");
+            RDN[] rdnsRfc = viaRfc.getRDNs(RFC4519Style.dnQualifier);
+            if (rdnsRfc.length != 1)
+            {
+                fail("RFC4519Style: alias '" + alias
+                    + "' did not parse to a single dnQualifier RDN");
+            }
+        }
+    }
+
     private void bogusEqualsTest()
         throws Exception
     {