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* and Distribution License("CDDL") (collectively, the "License"). You
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package com.sun.mail.pop3;
import java.util.*;
import java.net.*;
import java.io.*;
import java.security.*;
import java.util.logging.Level;
import javax.net.ssl.SSLSocket;
import com.sun.mail.util.PropUtil;
import com.sun.mail.util.MailLogger;
import com.sun.mail.util.SocketFetcher;
import com.sun.mail.util.LineInputStream;
import com.sun.mail.util.TraceInputStream;
import com.sun.mail.util.TraceOutputStream;
import com.sun.mail.util.SharedByteArrayOutputStream;
class Response {
boolean ok = false; // true if "+OK"
String data = null; // rest of line after "+OK" or "-ERR"
InputStream bytes = null; // all the bytes from a multi-line response
}
/**
* This class provides a POP3 connection and implements
* the POP3 protocol requests.
*
* APOP support courtesy of "chamness".
*
* @author Bill Shannon
*/
class Protocol {
private Socket socket; // POP3 socket
private String host; // host we're connected to
private Properties props; // session properties
private String prefix; // protocol name prefix, for props
private BufferedReader input; // input buf
private PrintWriter output; // output buf
private TraceInputStream traceInput;
private TraceOutputStream traceOutput;
private MailLogger logger;
private MailLogger traceLogger;
private String apopChallenge = null;
private Map capabilities = null;
private boolean pipelining;
private boolean noauthdebug = true; // hide auth info in debug output
private boolean traceSuspended; // temporarily suspend tracing
private static final int POP3_PORT = 110; // standard POP3 port
private static final String CRLF = "\r\n";
// sometimes the returned size isn't quite big enough
private static final int SLOP = 128;
/**
* Open a connection to the POP3 server.
*/
Protocol(String host, int port, MailLogger logger,
Properties props, String prefix, boolean isSSL)
throws IOException {
this.host = host;
this.props = props;
this.prefix = prefix;
this.logger = logger;
traceLogger = logger.getSubLogger("protocol", null);
noauthdebug = !PropUtil.getBooleanProperty(props,
"mail.debug.auth", false);
Response r;
boolean enableAPOP = getBoolProp(props, prefix + ".apop.enable");
boolean disableCapa = getBoolProp(props, prefix + ".disablecapa");
try {
if (port == -1)
port = POP3_PORT;
if (logger.isLoggable(Level.FINE))
logger.fine("connecting to host \"" + host +
"\", port " + port + ", isSSL " + isSSL);
socket = SocketFetcher.getSocket(host, port, props, prefix, isSSL);
initStreams();
r = simpleCommand(null);
} catch (IOException ioe) {
throw cleanupAndThrow(socket, ioe);
}
if (!r.ok) {
throw cleanupAndThrow(socket, new IOException("Connect failed"));
}
if (enableAPOP && r.data != null) {
int challStart = r.data.indexOf('<'); // start of challenge
int challEnd = r.data.indexOf('>', challStart); // end of challenge
if (challStart != -1 && challEnd != -1)
apopChallenge = r.data.substring(challStart, challEnd + 1);
logger.log(Level.FINE, "APOP challenge: {0}", apopChallenge);
}
// if server supports RFC 2449, set capabilities
if (!disableCapa)
setCapabilities(capa());
pipelining = hasCapability("PIPELINING") ||
PropUtil.getBooleanProperty(props, prefix + ".pipelining", false);
if (pipelining)
logger.config("PIPELINING enabled");
}
private static IOException cleanupAndThrow(Socket socket, IOException ife) {
try {
socket.close();
} catch (Throwable thr) {
if (isRecoverable(thr)) {
ife.addSuppressed(thr);
} else {
thr.addSuppressed(ife);
if (thr instanceof Error) {
throw (Error) thr;
}
if (thr instanceof RuntimeException) {
throw (RuntimeException) thr;
}
throw new RuntimeException("unexpected exception", thr);
}
}
return ife;
}
private static boolean isRecoverable(Throwable t) {
return (t instanceof Exception) || (t instanceof LinkageError);
}
/**
* Get the value of a boolean property.
* Print out the value if logging is enabled.
*/
private final synchronized boolean getBoolProp(Properties props,
String prop) {
boolean val = PropUtil.getBooleanProperty(props, prop, false);
if (logger.isLoggable(Level.CONFIG))
logger.config(prop + ": " + val);
return val;
}
private void initStreams() throws IOException {
boolean quote = PropUtil.getBooleanProperty(props,
"mail.debug.quote", false);
traceInput =
new TraceInputStream(socket.getInputStream(), traceLogger);
traceInput.setQuote(quote);
traceOutput =
new TraceOutputStream(socket.getOutputStream(), traceLogger);
traceOutput.setQuote(quote);
// should be US-ASCII, but not all JDK's support it so use iso-8859-1
input = new BufferedReader(new InputStreamReader(traceInput,
"iso-8859-1"));
output = new PrintWriter(
new BufferedWriter(
new OutputStreamWriter(traceOutput, "iso-8859-1")));
}
@Override
protected void finalize() throws Throwable {
try {
if (socket != null) // Forgot to logout ?!
quit();
} finally {
super.finalize();
}
}
/**
* Parse the capabilities from a CAPA response.
*/
synchronized void setCapabilities(InputStream in) {
if (in == null) {
capabilities = null;
return;
}
capabilities = new HashMap<>(10);
BufferedReader r = null;
try {
r = new BufferedReader(new InputStreamReader(in, "us-ascii"));
} catch (UnsupportedEncodingException ex) {
// should never happen
assert false;
}
String s;
try {
while ((s = r.readLine()) != null) {
String cap = s;
int i = cap.indexOf(' ');
if (i > 0)
cap = cap.substring(0, i);
capabilities.put(cap.toUpperCase(Locale.ENGLISH), s);
}
} catch (IOException ex) {
// should never happen
} finally {
try {
in.close();
} catch (IOException ex) { }
}
}
/**
* Check whether the given capability is supported by
* this server. Returns true if so, otherwise
* returns false.
*/
synchronized boolean hasCapability(String c) {
return capabilities != null &&
capabilities.containsKey(c.toUpperCase(Locale.ENGLISH));
}
/**
* Return the map of capabilities returned by the server.
*/
synchronized Map getCapabilities() {
return capabilities;
}
/**
* Login to the server, using the USER and PASS commands.
*/
synchronized String login(String user, String password)
throws IOException {
Response r;
// only pipeline password if connection is secure
boolean batch = pipelining && socket instanceof SSLSocket;
try {
if (noauthdebug && isTracing()) {
logger.fine("authentication command trace suppressed");
suspendTracing();
}
String dpw = null;
if (apopChallenge != null)
dpw = getDigest(password);
if (apopChallenge != null && dpw != null) {
r = simpleCommand("APOP " + user + " " + dpw);
} else if (batch) {
String cmd = "USER " + user;
batchCommandStart(cmd);
issueCommand(cmd);
cmd = "PASS " + password;
batchCommandContinue(cmd);
issueCommand(cmd);
r = readResponse();
if (!r.ok) {
String err = r.data != null ? r.data : "USER command failed";
readResponse(); // read and ignore PASS response
batchCommandEnd();
return err;
}
r = readResponse();
batchCommandEnd();
} else {
r = simpleCommand("USER " + user);
if (!r.ok)
return r.data != null ? r.data : "USER command failed";
r = simpleCommand("PASS " + password);
}
if (noauthdebug && isTracing())
logger.log(Level.FINE, "authentication command {0}",
(r.ok ? "succeeded" : "failed"));
if (!r.ok)
return r.data != null ? r.data : "login failed";
return null;
} finally {
resumeTracing();
}
}
/**
* Gets the APOP message digest.
* From RFC 1939:
*
* The 'digest' parameter is calculated by applying the MD5
* algorithm [RFC1321] to a string consisting of the timestamp
* (including angle-brackets) followed by a shared secret.
* The 'digest' parameter itself is a 16-octet value which is
* sent in hexadecimal format, using lower-case ASCII characters.
*
* @param password The APOP password
* @return The APOP digest or an empty string if an error occurs.
*/
private String getDigest(String password) {
String key = apopChallenge + password;
byte[] digest;
try {
MessageDigest md = MessageDigest.getInstance("MD5");
digest = md.digest(key.getBytes("iso-8859-1")); // XXX
} catch (NoSuchAlgorithmException nsae) {
return null;
} catch (UnsupportedEncodingException uee) {
return null;
}
return toHex(digest);
}
private static char[] digits = {
'0', '1', '2', '3', '4', '5', '6', '7',
'8', '9', 'a', 'b', 'c', 'd', 'e', 'f'
};
/**
* Convert a byte array to a string of hex digits representing the bytes.
*/
private static String toHex(byte[] bytes) {
char[] result = new char[bytes.length * 2];
for (int index = 0, i = 0; index < bytes.length; index++) {
int temp = bytes[index] & 0xFF;
result[i++] = digits[temp >> 4];
result[i++] = digits[temp & 0xF];
}
return new String(result);
}
/**
* Close down the connection, sending the QUIT command.
*/
synchronized boolean quit() throws IOException {
boolean ok = false;
try {
Response r = simpleCommand("QUIT");
ok = r.ok;
} finally {
close();
}
return ok;
}
/**
* Close the connection without sending any commands.
*/
void close() {
try {
socket.close();
} catch (IOException ex) {
// ignore it
} finally {
socket = null;
input = null;
output = null;
}
}
/**
* Return the total number of messages and mailbox size,
* using the STAT command.
*/
synchronized Status stat() throws IOException {
Response r = simpleCommand("STAT");
Status s = new Status();
/*
* Normally the STAT command shouldn't fail but apparently it
* does when accessing Hotmail too often, returning:
* -ERR login allowed only every 15 minutes
* (Why it doesn't just fail the login, I don't know.)
* This is a serious failure that we don't want to hide
* from the user.
*/
if (!r.ok)
throw new IOException("STAT command failed: " + r.data);
if (r.data != null) {
try {
StringTokenizer st = new StringTokenizer(r.data);
s.total = Integer.parseInt(st.nextToken());
s.size = Integer.parseInt(st.nextToken());
} catch (RuntimeException e) {
}
}
return s;
}
/**
* Return the size of the message using the LIST command.
*/
synchronized int list(int msg) throws IOException {
Response r = simpleCommand("LIST " + msg);
int size = -1;
if (r.ok && r.data != null) {
try {
StringTokenizer st = new StringTokenizer(r.data);
st.nextToken(); // skip message number
size = Integer.parseInt(st.nextToken());
} catch (RuntimeException e) {
// ignore it
}
}
return size;
}
/**
* Return the size of all messages using the LIST command.
*/
synchronized InputStream list() throws IOException {
Response r = multilineCommand("LIST", 128); // 128 == output size est
return r.bytes;
}
/**
* Retrieve the specified message.
* Given an estimate of the message's size we can be more efficient,
* preallocating the array and returning a SharedInputStream to allow
* us to share the array.
*/
synchronized InputStream retr(int msg, int size) throws IOException {
Response r;
String cmd;
boolean batch = size == 0 && pipelining;
if (batch) {
cmd = "LIST " + msg;
batchCommandStart(cmd);
issueCommand(cmd);
cmd = "RETR " + msg;
batchCommandContinue(cmd);
issueCommand(cmd);
r = readResponse();
if (r.ok && r.data != null) {
// parse the LIST response to get the message size
try {
StringTokenizer st = new StringTokenizer(r.data);
st.nextToken(); // skip message number
size = Integer.parseInt(st.nextToken());
// don't allow ridiculous sizes
if (size > 1024*1024*1024 || size < 0)
size = 0;
else {
if (logger.isLoggable(Level.FINE))
logger.fine("pipeline message size " + size);
size += SLOP;
}
} catch (RuntimeException e) {
}
}
r = readResponse();
if (r.ok)
r.bytes = readMultilineResponse(size + SLOP);
batchCommandEnd();
} else {
cmd = "RETR " + msg;
multilineCommandStart(cmd);
issueCommand(cmd);
r = readResponse();
if (!r.ok) {
multilineCommandEnd();
return null;
}
/*
* Many servers return a response to the RETR command of the form:
* +OK 832 octets
* If we don't have a size guess already, try to parse the response
* for data in that format and use it if found. It's only a guess,
* but it might be a good guess.
*/
if (size <= 0 && r.data != null) {
try {
StringTokenizer st = new StringTokenizer(r.data);
String s = st.nextToken();
String octets = st.nextToken();
if (octets.equals("octets")) {
size = Integer.parseInt(s);
// don't allow ridiculous sizes
if (size > 1024*1024*1024 || size < 0)
size = 0;
else {
if (logger.isLoggable(Level.FINE))
logger.fine("guessing message size: " + size);
size += SLOP;
}
}
} catch (RuntimeException e) {
}
}
r.bytes = readMultilineResponse(size);
multilineCommandEnd();
}
if (r.ok) {
if (size > 0 && logger.isLoggable(Level.FINE))
logger.fine("got message size " + r.bytes.available());
}
return r.bytes;
}
/**
* Retrieve the specified message and stream the content to the
* specified OutputStream. Return true on success.
*/
synchronized boolean retr(int msg, OutputStream os) throws IOException {
String cmd = "RETR " + msg;
multilineCommandStart(cmd);
issueCommand(cmd);
Response r = readResponse();
if (!r.ok) {
multilineCommandEnd();
return false;
}
Throwable terr = null;
int b, lastb = '\n';
try {
while ((b = input.read()) >= 0) {
if (lastb == '\n' && b == '.') {
b = input.read();
if (b == '\r') {
// end of response, consume LF as well
b = input.read();
break;
}
}
/*
* Keep writing unless we get an error while writing,
* which we defer until all of the data has been read.
*/
if (terr == null) {
try {
os.write(b);
} catch (IOException ex) {
logger.log(Level.FINE, "exception while streaming", ex);
terr = ex;
} catch (RuntimeException ex) {
logger.log(Level.FINE, "exception while streaming", ex);
terr = ex;
}
}
lastb = b;
}
} catch (InterruptedIOException iioex) {
/*
* As above in simpleCommand, close the socket to recover.
*/
try {
socket.close();
} catch (IOException cex) { }
throw iioex;
}
if (b < 0)
throw new EOFException("EOF on socket");
// was there a deferred error?
if (terr != null) {
if (terr instanceof IOException)
throw (IOException)terr;
if (terr instanceof RuntimeException)
throw (RuntimeException)terr;
assert false; // can't get here
}
multilineCommandEnd();
return true;
}
/**
* Return the message header and the first n lines of the message.
*/
synchronized InputStream top(int msg, int n) throws IOException {
Response r = multilineCommand("TOP " + msg + " " + n, 0);
return r.bytes;
}
/**
* Delete (permanently) the specified message.
*/
synchronized boolean dele(int msg) throws IOException {
Response r = simpleCommand("DELE " + msg);
return r.ok;
}
/**
* Return the UIDL string for the message.
*/
synchronized String uidl(int msg) throws IOException {
Response r = simpleCommand("UIDL " + msg);
if (!r.ok)
return null;
int i = r.data.indexOf(' ');
if (i > 0)
return r.data.substring(i + 1);
else
return null;
}
/**
* Return the UIDL strings for all messages.
* The UID for msg #N is returned in uids[N-1].
*/
synchronized boolean uidl(String[] uids) throws IOException {
Response r = multilineCommand("UIDL", 15 * uids.length);
if (!r.ok)
return false;
LineInputStream lis = new LineInputStream(r.bytes);
String line = null;
while ((line = lis.readLine()) != null) {
int i = line.indexOf(' ');
if (i < 1 || i >= line.length())
continue;
int n = Integer.parseInt(line.substring(0, i));
if (n > 0 && n <= uids.length)
uids[n - 1] = line.substring(i + 1);
}
try {
r.bytes.close();
} catch (IOException ex) {
// ignore it
}
return true;
}
/**
* Do a NOOP.
*/
synchronized boolean noop() throws IOException {
Response r = simpleCommand("NOOP");
return r.ok;
}
/**
* Do an RSET.
*/
synchronized boolean rset() throws IOException {
Response r = simpleCommand("RSET");
return r.ok;
}
/**
* Start TLS using STLS command specified by RFC 2595.
* If already using SSL, this is a nop and the STLS command is not issued.
*/
synchronized boolean stls() throws IOException {
if (socket instanceof SSLSocket)
return true; // nothing to do
Response r = simpleCommand("STLS");
if (r.ok) {
// it worked, now switch the socket into TLS mode
try {
socket = SocketFetcher.startTLS(socket, host, props, prefix);
initStreams();
} catch (IOException ioex) {
try {
socket.close();
} finally {
socket = null;
input = null;
output = null;
}
IOException sioex =
new IOException("Could not convert socket to TLS");
sioex.initCause(ioex);
throw sioex;
}
}
return r.ok;
}
/**
* Is this connection using SSL?
*/
synchronized boolean isSSL() {
return socket instanceof SSLSocket;
}
/**
* Get server capabilities using CAPA command specified by RFC 2449.
* Returns null if not supported.
*/
synchronized InputStream capa() throws IOException {
Response r = multilineCommand("CAPA", 128); // 128 == output size est
if (!r.ok)
return null;
return r.bytes;
}
/**
* Issue a simple POP3 command and return the response.
*/
private Response simpleCommand(String cmd) throws IOException {
simpleCommandStart(cmd);
issueCommand(cmd);
Response r = readResponse();
simpleCommandEnd();
return r;
}
/**
* Send the specified command.
*/
private void issueCommand(String cmd) throws IOException {
if (socket == null)
throw new IOException("Folder is closed"); // XXX
if (cmd != null) {
cmd += CRLF;
output.print(cmd); // do it in one write
output.flush();
}
}
/**
* Read the response to a command.
*/
private Response readResponse() throws IOException {
String line = null;
try {
line = input.readLine();
} catch (InterruptedIOException iioex) {
/*
* If we get a timeout while using the socket, we have no idea
* what state the connection is in. The server could still be
* alive, but slow, and could still be sending data. The only
* safe way to recover is to drop the connection.
*/
try {
socket.close();
} catch (IOException cex) { }
throw new EOFException(iioex.getMessage());
} catch (SocketException ex) {
/*
* If we get an error while using the socket, we have no idea
* what state the connection is in. The server could still be
* alive, but slow, and could still be sending data. The only
* safe way to recover is to drop the connection.
*/
try {
socket.close();
} catch (IOException cex) { }
throw new EOFException(ex.getMessage());
}
if (line == null) {
traceLogger.finest("");
throw new EOFException("EOF on socket");
}
Response r = new Response();
if (line.startsWith("+OK"))
r.ok = true;
else if (line.startsWith("-ERR"))
r.ok = false;
else
throw new IOException("Unexpected response: " + line);
int i;
if ((i = line.indexOf(' ')) >= 0)
r.data = line.substring(i + 1);
return r;
}
/**
* Issue a POP3 command that expects a multi-line response.
* size is an estimate of the response size.
*/
private Response multilineCommand(String cmd, int size) throws IOException {
multilineCommandStart(cmd);
issueCommand(cmd);
Response r = readResponse();
if (!r.ok) {
multilineCommandEnd();
return r;
}
r.bytes = readMultilineResponse(size);
multilineCommandEnd();
return r;
}
/**
* Read the response to a multiline command after the command response.
* The size parameter indicates the expected size of the response;
* the actual size can be different. Returns an InputStream to the
* response bytes.
*/
private InputStream readMultilineResponse(int size) throws IOException {
SharedByteArrayOutputStream buf = new SharedByteArrayOutputStream(size);
int b, lastb = '\n';
try {
while ((b = input.read()) >= 0) {
if (lastb == '\n' && b == '.') {
b = input.read();
if (b == '\r') {
// end of response, consume LF as well
b = input.read();
break;
}
}
buf.write(b);
lastb = b;
}
} catch (InterruptedIOException iioex) {
/*
* As above in readResponse, close the socket to recover.
*/
try {
socket.close();
} catch (IOException cex) { }
throw iioex;
}
if (b < 0)
throw new EOFException("EOF on socket");
return buf.toStream();
}
/**
* Is protocol tracing enabled?
*/
protected boolean isTracing() {
return traceLogger.isLoggable(Level.FINEST);
}
/**
* Temporarily turn off protocol tracing, e.g., to prevent
* tracing the authentication sequence, including the password.
*/
private void suspendTracing() {
if (traceLogger.isLoggable(Level.FINEST)) {
traceInput.setTrace(false);
traceOutput.setTrace(false);
}
}
/**
* Resume protocol tracing, if it was enabled to begin with.
*/
private void resumeTracing() {
if (traceLogger.isLoggable(Level.FINEST)) {
traceInput.setTrace(true);
traceOutput.setTrace(true);
}
}
/*
* Probe points for GlassFish monitoring.
*/
private void simpleCommandStart(String command) { }
private void simpleCommandEnd() { }
private void multilineCommandStart(String command) { }
private void multilineCommandEnd() { }
private void batchCommandStart(String command) { }
private void batchCommandContinue(String command) { }
private void batchCommandEnd() { }
}