/**
* Manage a local password, which is a cryptographically secure random number stored in a file with
* permissions that only allow the owner to read it. A new local password is generated each time the
* server starts. The asadmin client can use it to authenticate when executing local commands, such
* as stop-domain, without the user needing to supply a password.
*
* @author Bill Shannon
*/
@Service
@Scoped(Singleton.class) // only want one local password
public class LocalPasswordImpl implements PostConstruct, Init, LocalPassword {
@Inject ServerEnvironment env;
private String password;
private static final String LOCAL_PASSWORD_FILE = "local-password";
private static final int PASSWORD_BYTES = 20;
private static final char[] hex = {
'0', '1', '2', '3', '4', '5', '6', '7',
'8', '9', 'A', 'B', 'C', 'D', 'E', 'F'
};
private final Logger logger = Logger.getAnonymousLogger();
/** Generate a local password and save it in the local-password file. */
public void postConstruct() {
logger.fine("Generating local password");
SecureRandom random = new SecureRandom();
byte[] pwd = new byte[PASSWORD_BYTES];
random.nextBytes(pwd);
password = toHex(pwd);
File localPasswordFile = new File(env.getConfigDirPath(), LOCAL_PASSWORD_FILE);
PrintWriter w = null;
try {
if (!localPasswordFile.exists()) {
localPasswordFile.createNewFile();
/*
* XXX - There's a security hole here.
* Between the time the file is created and the permissions
* are changed to prevent others from opening it, someone
* else could open it and wait for the data to be written.
* Java needs the ability to create a file that's readable
* only by the owner; coming in JDK 7.
*/
localPasswordFile.setWritable(false, false); // take from all
localPasswordFile.setWritable(true, true); // owner only
localPasswordFile.setReadable(false, false); // take from all
localPasswordFile.setReadable(true, true); // owner only
}
w = new PrintWriter(localPasswordFile);
w.println(password);
} catch (IOException ex) {
// ignore errors
logger.log(Level.FINE, "Exception writing local password file", ex);
} finally {
if (w != null) w.close();
}
}
/** Is the given password the local password? */
public boolean isLocalPassword(String p) {
return password != null && password.equals(p);
}
/** Get the local password. */
public String getLocalPassword() {
return password;
}
/** Convert the byte array to a hex string. */
private static String toHex(byte[] b) {
char[] bc = new char[b.length * 2];
for (int i = 0, j = 0; i < b.length; i++) {
byte bb = b[i];
bc[j++] = hex[(bb >> 4) & 0xF];
bc[j++] = hex[bb & 0xF];
}
return new String(bc);
}
}
