static UserPrincipal lookup(String name) throws IOException {
SecurityManager sm = System.getSecurityManager();
if (sm != null) {
sm.checkPermission(new RuntimePermission("lookupUserInformation"));
}
// invoke LookupAccountName to get buffer size needed for SID
int size = 0;
try {
size = LookupAccountName(name, 0L, 0);
} catch (WindowsException x) {
if (x.lastError() == ERROR_NONE_MAPPED) throw new UserPrincipalNotFoundException(name);
throw new IOException(name + ": " + x.errorString());
}
assert size > 0;
// allocate buffer and re-invoke LookupAccountName get SID
NativeBuffer sidBuffer = NativeBuffers.getNativeBuffer(size);
try {
int newSize = LookupAccountName(name, sidBuffer.address(), size);
if (newSize != size) {
// can this happen?
throw new AssertionError("SID change during lookup");
}
// return user principal
return fromSid(sidBuffer.address());
} catch (WindowsException x) {
throw new IOException(name + ": " + x.errorString());
} finally {
sidBuffer.release();
}
}
static UserPrincipal fromSid(long sidAddress) throws IOException {
String sidString;
try {
sidString = ConvertSidToStringSid(sidAddress);
if (sidString == null) {
// pre-Windows XP system?
throw new AssertionError();
}
} catch (WindowsException x) {
throw new IOException("Unable to convert SID to String: " + x.errorString());
}
// lookup account; if not available then use the SID as the name
Account account = null;
String name;
try {
account = LookupAccountSid(sidAddress);
name = account.domain() + "\\" + account.name();
} catch (WindowsException x) {
name = sidString;
}
int sidType = (account == null) ? SidTypeUnknown : account.use();
if ((sidType == SidTypeGroup)
|| (sidType == SidTypeWellKnownGroup)
|| (sidType == SidTypeAlias)) // alias for local group
{
return new Group(sidString, sidType, name);
} else {
return new User(sidString, sidType, name);
}
}