private static byte[] prepare(byte[] src, StringPrep prep)
throws ParseException, UnsupportedEncodingException {
String s = new String(src, "UTF-8");
UCharacterIterator iter = UCharacterIterator.getInstance(s);
StringBuffer out = prep.prepare(iter, StringPrep.DEFAULT);
return out.toString().getBytes("UTF-8");
}
//
// toUnicode operation; should only apply to a single label
//
private static String toUnicodeInternal(String label, int flag) {
boolean[] caseFlags = null;
StringBuffer dest;
// step 1
// find out if all the codepoints in input are ASCII
boolean isASCII = isAllASCII(label);
if (!isASCII) {
// step 2
// perform the nameprep operation; flag ALLOW_UNASSIGNED is used here
try {
UCharacterIterator iter = UCharacterIterator.getInstance(label);
dest = namePrep.prepare(iter, flag);
} catch (Exception e) {
// toUnicode never fails; if any step fails, return the input string
return label;
}
} else {
dest = new StringBuffer(label);
}
// step 3
// verify ACE Prefix
if (startsWithACEPrefix(dest)) {
// step 4
// Remove the ACE Prefix
String temp = dest.substring(ACE_PREFIX_LENGTH, dest.length());
try {
// step 5
// Decode using punycode
StringBuffer decodeOut = Punycode.decode(new StringBuffer(temp), null);
// step 6
// Apply toASCII
String toASCIIOut = toASCII(decodeOut.toString(), flag);
// step 7
// verify
if (toASCIIOut.equalsIgnoreCase(dest.toString())) {
// step 8
// return output of step 5
return decodeOut.toString();
}
} catch (Exception ignored) {
// no-op
}
}
// just return the input
return label;
}
//
// toASCII operation; should only apply to a single label
//
private static String toASCIIInternal(String label, int flag) {
// step 1
// Check if the string contains code points outside the ASCII range 0..0x7c.
boolean isASCII = isAllASCII(label);
StringBuffer dest;
// step 2
// perform the nameprep operation; flag ALLOW_UNASSIGNED is used here
if (!isASCII) {
UCharacterIterator iter = UCharacterIterator.getInstance(label);
try {
dest = namePrep.prepare(iter, flag);
} catch (java.text.ParseException e) {
throw new IllegalArgumentException(e);
}
} else {
dest = new StringBuffer(label);
}
// step 8, move forward to check the smallest number of the code points
// the length must be inside 1..63
if (dest.length() == 0) {
throw new IllegalArgumentException("Empty label is not a legal name");
}
// step 3
// Verify the absence of non-LDH ASCII code points
// 0..0x2c, 0x2e..0x2f, 0x3a..0x40, 0x5b..0x60, 0x7b..0x7f
// Verify the absence of leading and trailing hyphen
boolean useSTD3ASCIIRules = ((flag & USE_STD3_ASCII_RULES) != 0);
if (useSTD3ASCIIRules) {
for (int i = 0; i < dest.length(); i++) {
int c = dest.charAt(i);
if (isNonLDHAsciiCodePoint(c)) {
throw new IllegalArgumentException("Contains non-LDH ASCII characters");
}
}
if (dest.charAt(0) == '-' || dest.charAt(dest.length() - 1) == '-') {
throw new IllegalArgumentException("Has leading or trailing hyphen");
}
}
if (!isASCII) {
// step 4
// If all code points are inside 0..0x7f, skip to step 8
if (!isAllASCII(dest.toString())) {
// step 5
// verify the sequence does not begin with ACE prefix
if (!startsWithACEPrefix(dest)) {
// step 6
// encode the sequence with punycode
try {
dest = Punycode.encode(dest, null);
} catch (java.text.ParseException e) {
throw new IllegalArgumentException(e);
}
dest = toASCIILower(dest);
// step 7
// prepend the ACE prefix
dest.insert(0, ACE_PREFIX);
} else {
throw new IllegalArgumentException("The input starts with the ACE Prefix");
}
}
}
// step 8
// the length must be inside 1..63
if (dest.length() > MAX_LABEL_LENGTH) {
throw new IllegalArgumentException("The label in the input is too long");
}
return dest.toString();
}