private List<String> executeSimpleCommand(String command, boolean sensitive)
throws IOException, MessagingException {
List<String> results = new ArrayList<String>();
if (command != null) {
writeLine(command, sensitive);
}
/*
* Read lines as long as the length is 4 or larger, e.g. "220-banner text here".
* Shorter lines are either errors of contain only a reply code. Those cases will
* be handled by checkLine() below.
*/
String line = readLine();
while (line.length() >= 4) {
if (line.length() > 4) {
// Everything after the first four characters goes into the results array.
results.add(line.substring(4));
}
if (line.charAt(3) != '-') {
// If the fourth character isn't "-" this is the last line of the response.
break;
}
line = readLine();
}
// Check if the reply code indicates an error.
checkLine(line);
return results;
}
private void saslAuthCramMD5(String username, String password)
throws MessagingException, AuthenticationFailedException, IOException {
List<String> respList = executeSimpleCommand("AUTH CRAM-MD5");
if (respList.size() != 1) {
throw new AuthenticationFailedException("Unable to negotiate CRAM-MD5");
}
String b64Nonce = respList.get(0);
String b64CRAMString = Authentication.computeCramMd5(mUsername, mPassword, b64Nonce);
try {
executeSimpleCommand(b64CRAMString, true);
} catch (MessagingException me) {
throw new AuthenticationFailedException("Unable to negotiate MD5 CRAM");
}
}
@Override
public void open() throws MessagingException {
try {
InetAddress[] addresses = InetAddress.getAllByName(mHost);
for (int i = 0; i < addresses.length; i++) {
try {
SocketAddress socketAddress = new InetSocketAddress(addresses[i], mPort);
if (mConnectionSecurity == CONNECTION_SECURITY_SSL_REQUIRED
|| mConnectionSecurity == CONNECTION_SECURITY_SSL_OPTIONAL) {
SSLContext sslContext = SSLContext.getInstance("TLS");
boolean secure = mConnectionSecurity == CONNECTION_SECURITY_SSL_REQUIRED;
sslContext.init(
null,
new TrustManager[] {TrustManagerFactory.get(mHost, secure)},
new SecureRandom());
mSocket = sslContext.getSocketFactory().createSocket();
mSocket.connect(socketAddress, SOCKET_CONNECT_TIMEOUT);
mSecure = true;
} else {
mSocket = new Socket();
mSocket.connect(socketAddress, SOCKET_CONNECT_TIMEOUT);
}
} catch (ConnectException e) {
if (i < (addresses.length - 1)) {
// there are still other addresses for that host to try
continue;
}
throw new MessagingException("Cannot connect to host", e);
}
break; // connection success
}
// RFC 1047
mSocket.setSoTimeout(SOCKET_READ_TIMEOUT);
mIn = new PeekableInputStream(new BufferedInputStream(mSocket.getInputStream(), 1024));
mOut = mSocket.getOutputStream();
// Eat the banner
executeSimpleCommand(null);
InetAddress localAddress = mSocket.getLocalAddress();
String localHost = localAddress.getCanonicalHostName();
String ipAddr = localAddress.getHostAddress();
if (localHost.equals("") || localHost.equals(ipAddr) || localHost.contains("_")) {
// We don't have a FQDN or the hostname contains invalid
// characters (see issue 2143), so use IP address.
if (!ipAddr.equals("")) {
if (localAddress instanceof Inet6Address) {
localHost = "[IPV6:" + ipAddr + "]";
} else {
localHost = "[" + ipAddr + "]";
}
} else {
// If the IP address is no good, set a sane default (see issue 2750).
localHost = "android";
}
}
List<String> results = executeSimpleCommand("EHLO " + localHost);
m8bitEncodingAllowed = results.contains("8BITMIME");
/*
* TODO may need to add code to fall back to HELO I switched it from
* using HELO on non STARTTLS connections because of AOL's mail
* server. It won't let you use AUTH without EHLO.
* We should really be paying more attention to the capabilities
* and only attempting auth if it's available, and warning the user
* if not.
*/
if (mConnectionSecurity == CONNECTION_SECURITY_TLS_OPTIONAL
|| mConnectionSecurity == CONNECTION_SECURITY_TLS_REQUIRED) {
if (results.contains("STARTTLS")) {
executeSimpleCommand("STARTTLS");
SSLContext sslContext = SSLContext.getInstance("TLS");
boolean secure = mConnectionSecurity == CONNECTION_SECURITY_TLS_REQUIRED;
sslContext.init(
null,
new TrustManager[] {TrustManagerFactory.get(mHost, secure)},
new SecureRandom());
mSocket = sslContext.getSocketFactory().createSocket(mSocket, mHost, mPort, true);
mIn = new PeekableInputStream(new BufferedInputStream(mSocket.getInputStream(), 1024));
mOut = mSocket.getOutputStream();
mSecure = true;
/*
* Now resend the EHLO. Required by RFC2487 Sec. 5.2, and more specifically,
* Exim.
*/
results = executeSimpleCommand("EHLO " + localHost);
} else if (mConnectionSecurity == CONNECTION_SECURITY_TLS_REQUIRED) {
throw new MessagingException("TLS not supported but required");
}
}
boolean useAuthLogin = AUTH_LOGIN.equals(mAuthType);
boolean useAuthPlain = AUTH_PLAIN.equals(mAuthType);
boolean useAuthCramMD5 = AUTH_CRAM_MD5.equals(mAuthType);
// Automatically choose best authentication method if none was explicitly selected
boolean useAutomaticAuth = !(useAuthLogin || useAuthPlain || useAuthCramMD5);
boolean authLoginSupported = false;
boolean authPlainSupported = false;
boolean authCramMD5Supported = false;
for (String result : results) {
if (result.matches(".*AUTH.*LOGIN.*$")) {
authLoginSupported = true;
}
if (result.matches(".*AUTH.*PLAIN.*$")) {
authPlainSupported = true;
}
if (result.matches(".*AUTH.*CRAM-MD5.*$")) {
authCramMD5Supported = true;
}
if (result.matches(".*SIZE \\d*$")) {
try {
mLargestAcceptableMessage =
Integer.parseInt(result.substring(result.lastIndexOf(' ') + 1));
} catch (Exception e) {
if (K9.DEBUG && K9.DEBUG_PROTOCOL_SMTP) {
Log.d(
K9.LOG_TAG,
"Tried to parse " + result + " and get an int out of the last word",
e);
}
}
}
}
if (mUsername != null
&& mUsername.length() > 0
&& mPassword != null
&& mPassword.length() > 0) {
if (useAuthCramMD5 || (useAutomaticAuth && authCramMD5Supported)) {
if (!authCramMD5Supported && K9.DEBUG && K9.DEBUG_PROTOCOL_SMTP) {
Log.d(
K9.LOG_TAG,
"Using CRAM_MD5 as authentication method although the "
+ "server didn't advertise support for it in EHLO response.");
}
saslAuthCramMD5(mUsername, mPassword);
} else if (useAuthPlain || (useAutomaticAuth && authPlainSupported)) {
if (!authPlainSupported && K9.DEBUG && K9.DEBUG_PROTOCOL_SMTP) {
Log.d(
K9.LOG_TAG,
"Using PLAIN as authentication method although the "
+ "server didn't advertise support for it in EHLO response.");
}
try {
saslAuthPlain(mUsername, mPassword);
} catch (MessagingException ex) {
// PLAIN is a special case. Historically, PLAIN has represented both PLAIN and LOGIN;
// only the
// protocol being advertised by the server would be used, with PLAIN taking precedence.
// Instead
// of using only the requested protocol, we'll try PLAIN and then try LOGIN.
if (useAuthPlain && authLoginSupported) {
if (K9.DEBUG && K9.DEBUG_PROTOCOL_SMTP) {
Log.d(K9.LOG_TAG, "Using legacy PLAIN authentication behavior and trying LOGIN.");
}
saslAuthLogin(mUsername, mPassword);
} else {
// If it was auto detected and failed, continue throwing the exception back up.
throw ex;
}
}
} else if (useAuthLogin || (useAutomaticAuth && authLoginSupported)) {
if (!authPlainSupported && K9.DEBUG && K9.DEBUG_PROTOCOL_SMTP) {
Log.d(
K9.LOG_TAG,
"Using LOGIN as authentication method although the "
+ "server didn't advertise support for it in EHLO response.");
}
saslAuthLogin(mUsername, mPassword);
} else {
throw new MessagingException("No valid authentication mechanism found.");
}
}
} catch (SSLException e) {
throw new CertificateValidationException(e.getMessage(), e);
} catch (GeneralSecurityException gse) {
throw new MessagingException(
"Unable to open connection to SMTP server due to security error.", gse);
} catch (IOException ioe) {
throw new MessagingException("Unable to open connection to SMTP server.", ioe);
}
}