panda.net.imap.AuthenticatingIMAPClient Maven / Gradle / Ivy
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Panda Nets is a client side library of many basic Internet protocols.
package panda.net.imap;
import java.io.IOException;
import java.security.InvalidKeyException;
import java.security.NoSuchAlgorithmException;
import java.security.spec.InvalidKeySpecException;
import javax.crypto.Mac;
import javax.crypto.spec.SecretKeySpec;
import javax.net.ssl.SSLContext;
import panda.codec.binary.Base64;
/**
* An IMAP Client class with authentication support.
*
* @see IMAPSClient
*/
public class AuthenticatingIMAPClient extends IMAPSClient {
/**
* Constructor for AuthenticatingIMAPClient that delegates to IMAPSClient. Sets security mode to
* explicit (isImplicit = false).
*/
public AuthenticatingIMAPClient() {
this(DEFAULT_PROTOCOL, false);
}
/**
* Constructor for AuthenticatingIMAPClient that delegates to IMAPSClient.
*
* @param implicit The security mode (Implicit/Explicit).
*/
public AuthenticatingIMAPClient(boolean implicit) {
this(DEFAULT_PROTOCOL, implicit);
}
/**
* Constructor for AuthenticatingIMAPClient that delegates to IMAPSClient.
*
* @param proto the protocol.
*/
public AuthenticatingIMAPClient(String proto) {
this(proto, false);
}
/**
* Constructor for AuthenticatingIMAPClient that delegates to IMAPSClient.
*
* @param proto the protocol.
* @param implicit The security mode(Implicit/Explicit).
*/
public AuthenticatingIMAPClient(String proto, boolean implicit) {
this(proto, implicit, null);
}
/**
* Constructor for AuthenticatingIMAPClient that delegates to IMAPSClient.
*
* @param proto the protocol.
* @param implicit The security mode(Implicit/Explicit).
* @param ctx the context
*/
public AuthenticatingIMAPClient(String proto, boolean implicit, SSLContext ctx) {
super(proto, implicit, ctx);
}
/**
* Constructor for AuthenticatingIMAPClient that delegates to IMAPSClient.
*
* @param implicit The security mode(Implicit/Explicit).
* @param ctx A pre-configured SSL Context.
*/
public AuthenticatingIMAPClient(boolean implicit, SSLContext ctx) {
this(DEFAULT_PROTOCOL, implicit, ctx);
}
/**
* Constructor for AuthenticatingIMAPClient that delegates to IMAPSClient.
*
* @param context A pre-configured SSL Context.
*/
public AuthenticatingIMAPClient(SSLContext context) {
this(false, context);
}
/**
* Authenticate to the IMAP server by sending the AUTHENTICATE command with the selected
* mechanism, using the given username and the given password.
*
* @param method the method name
* @param username user
* @param password password
* @return True if successfully completed, false if not.
* @exception IOException If an I/O error occurs while either sending a command to the server or
* receiving a reply from the server.
* @exception NoSuchAlgorithmException If the CRAM hash algorithm cannot be instantiated by the
* Java runtime system.
* @exception InvalidKeyException If the CRAM hash algorithm failed to use the given password.
* @exception InvalidKeySpecException If the CRAM hash algorithm failed to use the given
* password.
*/
public boolean authenticate(AuthenticatingIMAPClient.AUTH_METHOD method, String username, String password)
throws IOException, NoSuchAlgorithmException, InvalidKeyException, InvalidKeySpecException {
return auth(method, username, password);
}
/**
* Authenticate to the IMAP server by sending the AUTHENTICATE command with the selected
* mechanism, using the given username and the given password.
*
* @param method the method name
* @param username user
* @param password password
* @return True if successfully completed, false if not.
* @exception IOException If an I/O error occurs while either sending a command to the server or
* receiving a reply from the server.
* @exception NoSuchAlgorithmException If the CRAM hash algorithm cannot be instantiated by the
* Java runtime system.
* @exception InvalidKeyException If the CRAM hash algorithm failed to use the given password.
* @exception InvalidKeySpecException If the CRAM hash algorithm failed to use the given
* password.
*/
public boolean auth(AuthenticatingIMAPClient.AUTH_METHOD method, String username, String password)
throws IOException, NoSuchAlgorithmException, InvalidKeyException, InvalidKeySpecException {
if (!IMAPReply.isContinuation(sendCommand(IMAPCommand.AUTHENTICATE, method.getAuthName()))) {
return false;
}
switch (method) {
case PLAIN: {
// the server sends an empty response ("+ "), so we don't have to read it.
int result = sendData(Base64.encodeBase64String(("\000" + username + "\000" + password)
.getBytes(getCharsetName()))); // Java 1.6 can use getCharset()
if (result == IMAPReply.OK) {
setState(IMAP.IMAPState.AUTH_STATE);
}
return result == IMAPReply.OK;
}
case CRAM_MD5: {
// get the CRAM challenge (after "+ ")
byte[] serverChallenge = Base64.decodeBase64(getReplyString().substring(2).trim());
// get the Mac instance
Mac hmac_md5 = Mac.getInstance("HmacMD5");
hmac_md5.init(new SecretKeySpec(password.getBytes(getCharsetName()), "HmacMD5")); // Java
// 1.6
// can
// use
// getCharset()
// compute the result:
// Java 1.6 can use getCharset()
byte[] hmacResult = _convertToHexString(hmac_md5.doFinal(serverChallenge)).getBytes(getCharsetName());
// join the byte arrays to form the reply
byte[] usernameBytes = username.getBytes(getCharsetName()); // Java 1.6 can use
// getCharset()
byte[] toEncode = new byte[usernameBytes.length + 1 /* the space */+ hmacResult.length];
System.arraycopy(usernameBytes, 0, toEncode, 0, usernameBytes.length);
toEncode[usernameBytes.length] = ' ';
System.arraycopy(hmacResult, 0, toEncode, usernameBytes.length + 1, hmacResult.length);
// send the reply and read the server code:
int result = sendData(Base64.encodeBase64String(toEncode));
if (result == IMAPReply.OK) {
setState(IMAP.IMAPState.AUTH_STATE);
}
return result == IMAPReply.OK;
}
case LOGIN: {
// the server sends fixed responses (base64("Username") and
// base64("Password")), so we don't have to read them.
if (sendData(
// Java 1.6 can use getCharset()
Base64.encodeBase64String(username.getBytes(getCharsetName()))) != IMAPReply.CONT) {
return false;
}
// Java 1.6 can use getCharset()
int result = sendData(Base64.encodeBase64String(password.getBytes(getCharsetName())));
if (result == IMAPReply.OK) {
setState(IMAP.IMAPState.AUTH_STATE);
}
return result == IMAPReply.OK;
}
case XOAUTH: {
int result = sendData(username);
if (result == IMAPReply.OK) {
setState(IMAP.IMAPState.AUTH_STATE);
}
return result == IMAPReply.OK;
}
}
return false; // safety check
}
/**
* Converts the given byte array to a String containing the hex values of the bytes. For
* example, the byte 'A' will be converted to '41', because this is the ASCII code (and the byte
* value) of the capital letter 'A'.
*
* @param a The byte array to convert.
* @return The resulting String of hex codes.
*/
private String _convertToHexString(byte[] a) {
StringBuilder result = new StringBuilder(a.length * 2);
for (byte element : a) {
if ((element & 0x0FF) <= 15) {
result.append("0");
}
result.append(Integer.toHexString(element & 0x0FF));
}
return result.toString();
}
/**
* The enumeration of currently-supported authentication methods.
*/
public static enum AUTH_METHOD {
/** The standarised (RFC4616) PLAIN method, which sends the password unencrypted (insecure). */
PLAIN("PLAIN"),
/** The standarised (RFC2195) CRAM-MD5 method, which doesn't send the password (secure). */
CRAM_MD5("CRAM-MD5"),
/**
* The unstandarised Microsoft LOGIN method, which sends the password unencrypted
* (insecure).
*/
LOGIN("LOGIN"),
/** XOAUTH */
XOAUTH("XOAUTH");
private final String authName;
private AUTH_METHOD(String name) {
this.authName = name;
}
/**
* Gets the name of the given authentication method suitable for the server.
*
* @return The name of the given authentication method suitable for the server.
*/
public final String getAuthName() {
return authName;
}
}
}
/* kate: indent-width 4; replace-tabs on; */
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