/*
* The MIT License
*
* Copyright (c) 2009, Sun Microsystems, Inc.
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
package org.jvnet.libpam;
import com.sun.jna.Pointer;
import com.sun.jna.ptr.PointerByReference;
import org.jboss.logging.Logger;
import org.jvnet.libpam.impl.CLibrary.passwd;
import org.jvnet.libpam.impl.PAMLibrary.pam_conv;
import org.jvnet.libpam.impl.PAMLibrary.pam_conv.PamCallback;
import org.jvnet.libpam.impl.PAMLibrary.pam_handle_t;
import org.jvnet.libpam.impl.PAMLibrary.pam_message;
import org.jvnet.libpam.impl.PAMLibrary.pam_response;
import java.util.Set;
import static com.sun.jna.Native.POINTER_SIZE;
import static org.jvnet.libpam.impl.CLibrary.libc;
import static org.jvnet.libpam.impl.PAMLibrary.PAM_CONV_ERR;
import static org.jvnet.libpam.impl.PAMLibrary.PAM_PROMPT_ECHO_OFF;
import static org.jvnet.libpam.impl.PAMLibrary.PAM_SUCCESS;
import static org.jvnet.libpam.impl.PAMLibrary.PAM_USER;
import static org.jvnet.libpam.impl.PAMLibrary.libpam;
/**
* PAM authenticator.
* <p>
* <p>
* Instances are thread unsafe and non reentrant. An instace cannot be reused
* to authenticate multiple users.
* <p>
* <p>
* For an overview of PAM programming, refer to the following resources:
* <p>
* <ul>
* <li><a href="http://www.netbsd.org/docs/guide/en/chap-pam.html">NetBSD PAM programming guide</a>
* <li><a href="http://www.kernel.org/pub/linux/libs/pam/">Linux PAM</a>
* </ul>
*
* @author Kohsuke Kawaguchi
*/
public class PAM {
private pam_handle_t pht;
private int ret;
/**
* Temporarily stored to pass a value from {@link #authenticate(String, String...)}
* to {@link pam_conv}.
*/
private String[] factors;
/**
* Creates a new authenticator.
*
* @param serviceName PAM service name. This corresponds to the service name that shows up
* in the PAM configuration,
*/
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.debug("pam_conv num_msg=" + num_msg);
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 < factors.length; i++) {
pam_message pm = new pam_message(msg.getPointer(POINTER_SIZE * i));
LOGGER.debug(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(factors[i]);
r.write(); // write to (*resp)[i]
}
}
return PAM_SUCCESS;
}
});
PointerByReference phtr = new PointerByReference();
check(libpam.pam_start(serviceName, null, conv, phtr), "pam_start failed");
pht = new pam_handle_t(phtr.getValue());
}
private void check(int ret, String msg) throws PAMException {
this.ret = ret;
if (ret != 0) {
if (pht != null)
throw new PAMException(msg + " : " + libpam.pam_strerror(pht, ret));
else
throw new PAMException(msg);
}
}
/**
* Authenticate the user with a password.
*
* @return Upon a successful authentication, return information about the user.
* @throws PAMException If the authentication fails.
*/
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");
check(libpam.pam_setcred(pht, 0), "pam_setcred failed");
// several different error code seem to be used to represent authentication failures
check(libpam.pam_acct_mgmt(pht,0),"pam_acct_mgmt failed");
PointerByReference r = new PointerByReference();
check(libpam.pam_get_item(pht, PAM_USER, r), "pam_get_item failed");
String userName = r.getValue().getString(0);
passwd pwd = libc.getpwnam(userName);
if (pwd == null)
throw new PAMException("Authentication succeeded but no user information is available");
return new UnixUser(userName, pwd);
} finally {
this.factors = null;
}
}
/**
* Returns the groups a user belongs to
*
* @param username
* @return Set of group names
* @throws PAMException
* @deprecated Pointless and ugly convenience method.
*/
public Set<String> getGroupsOfUser(String username) throws PAMException {
return new UnixUser(username).getGroups();
}
/**
* After a successful authentication, call this method to obtain the effective user name.
* This can be different from the user name that you passed to the {@link #authenticate(String, String)}
* method.
*/
/**
* Performs an early disposal of the object, instead of letting this GC-ed.
* Since PAM may hold on to native resources that don't put pressure on Java GC,
* doing this is a good idea.
* <p>
* <p>
* This method is called by {@link #finalize()}, too, so it's not required
* to call this method explicitly, however.
*/
public void dispose() {
if (pht != null) {
libpam.pam_end(pht, ret);
pht = null;
}
}
@Override
protected void finalize() throws Throwable {
super.finalize();
dispose();
}
private static final Logger LOGGER = Logger.getLogger(PAM.class.getName());
}