Add multi-factor authentication support

src/main/java/org/jvnet/libpam/PAM.java

@@ -57,10 +57,10 @@ public class PAM {
  private int ret;
 
  /**
- * Temporarily stored to pass a value from {@link #authenticate(String, String)}
+ * Temporarily stored to pass a value from {@link #authenticate(String, String...)}
  * to {@link pam_conv}.
  */
- private String password;
+ private String[] factors;
 
  /**
  * Creates a new authenticator.
@@ -73,19 +73,19 @@ public PAM(String serviceName) throws PAMException {
  pam_conv conv = new pam_conv(new PamCallback() {
  public int callback(int num_msg, Pointer msg, Pointer resp, Pointer _) {
  LOGGER.fine("pam_conv num_msg="+num_msg);
- if(password==null)
+ if(factors==null)
  return PAM_CONV_ERR;
 
  // allocates pam_response[num_msg]. the caller will free this
  Pointer m = libc.calloc(pam_response.SIZE,num_msg);
  resp.setPointer(0,m);
 
- for( int i=0; i<num_msg; i++ ) {
+ for( int i=0; i<factors.length; i++ ) {
  pam_message pm = new pam_message(msg.getPointer(POINTER_SIZE*i));
  LOGGER.fine(pm.msg_style+":"+pm.msg);
- if(pm.msg_style==PAM_PROMPT_ECHO_OFF) {
- pam_response r = new pam_response(m.share(pam_response.SIZE*i));
- r.setResp(password);
+ if (pm.msg_style == PAM_PROMPT_ECHO_OFF) {
+ pam_response r = new pam_response(m.share(pam_response.SIZE * i));
+ r.setResp(factors[i]);
  r.write(); // write to (*resp)[i]
  }
  }
@@ -117,8 +117,8 @@ private void check(int ret, String msg) throws PAMException {
  * @throws PAMException
  * If the authentication fails.
  */
- public UnixUser authenticate(String username, String password) throws PAMException {
- this.password = password;
+ public UnixUser authenticate(String username, String... factors) throws PAMException {
+ this.factors = factors;
  try {
  check(libpam.pam_set_item(pht,PAM_USER,username),"pam_set_item failed");
  check(libpam.pam_authenticate(pht,0),"pam_authenticate failed");
@@ -134,7 +134,7 @@ public UnixUser authenticate(String username, String password) throws PAMExcepti
  throw new PAMException("Authentication succeeded but no user information is available");
  return new UnixUser(userName,pwd);
  } finally {
- this.password = null;
+ this.factors = null;
  }
  }
 
@@ -180,4 +180,4 @@ protected void finalize() throws Throwable {
  }
 
  private static final Logger LOGGER = Logger.getLogger(PAM.class.getName());
-}
+}