private static String computeDigestAuthentication(Realm realm) {
StringBuilder builder = new StringBuilder().append("Digest ");
append(builder, "username", realm.getPrincipal(), true);
append(builder, "realm", realm.getRealmName(), true);
append(builder, "nonce", realm.getNonce(), true);
append(builder, "uri", computeRealmURI(realm), true);
if (isNonEmpty(realm.getAlgorithm())) append(builder, "algorithm", realm.getAlgorithm(), false);
append(builder, "response", realm.getResponse(), true);
if (realm.getOpaque() != null) append(builder, "opaque", realm.getOpaque(), true);
if (realm.getQop() != null) {
append(builder, "qop", realm.getQop(), false);
// nc and cnonce only sent if server sent qop
append(builder, "nc", realm.getNc(), false);
append(builder, "cnonce", realm.getCnonce(), true);
}
builder.setLength(builder.length() - 2); // remove tailing ", "
// FIXME isn't there a more efficient way?
return new String(StringUtils.charSequence2Bytes(builder, ISO_8859_1));
}