private static ClientServerHello exchange(
String softwareversion, InputStream bi, OutputStream bo, boolean clientMode)
throws IOException {
String localIdentifier = "SSH-2.0-" + softwareversion;
String remoteIdentifier = null;
bo.write(StringEncoder.GetBytes(localIdentifier + "\r\n"));
bo.flush();
byte[] remoteData = new byte[1024];
for (int i = 0; i < 50; i++) {
int len = readLineRN(bi, remoteData);
remoteIdentifier = StringEncoder.GetString(remoteData, 0, len);
if (remoteIdentifier.startsWith("SSH-")) break;
}
if (remoteIdentifier.startsWith("SSH-") == false)
throw new IOException(
"Malformed SSH identification string. There was no line starting with 'SSH-' amongst the first 50 lines.");
if (!remoteIdentifier.startsWith("SSH-1.99-") && !remoteIdentifier.startsWith("SSH-2.0-"))
throw new IOException("Remote party uses incompatible protocol, it is not SSH-2 compatible.");
if (clientMode) return new ClientServerHello(localIdentifier, remoteIdentifier);
else return new ClientServerHello(remoteIdentifier, localIdentifier);
}
public String readString() throws IOException {
int len = readUINT32();
if ((len + pos) > max) throw new IOException("Malformed SSH string.");
String res = StringEncoder.GetString(arr, pos, len);
pos += len;
return res;
}
private void establishConnection(ProxyData proxyData, int connectTimeout) throws IOException {
/* See the comment for createInetAddress() */
if (proxyData == null) {
InetAddress addr = createInetAddress(hostname);
sock.connect(new InetSocketAddress(addr, port), connectTimeout);
return;
}
if (proxyData instanceof HTTPProxyData) {
HTTPProxyData pd = (HTTPProxyData) proxyData;
/* At the moment, we only support HTTP proxies */
InetAddress addr = createInetAddress(pd.proxyHost);
sock.connect(new InetSocketAddress(addr, pd.proxyPort), connectTimeout);
/* OK, now tell the proxy where we actually want to connect to */
StringBuilder sb = new StringBuilder();
sb.append("CONNECT ");
sb.append(hostname);
sb.append(':');
sb.append(port);
sb.append(" HTTP/1.0\r\n");
if ((pd.proxyUser != null) && (pd.proxyPass != null)) {
String credentials = pd.proxyUser + ":" + pd.proxyPass;
char[] encoded = Base64.encode(StringEncoder.GetBytes(credentials));
sb.append("Proxy-Authorization: Basic ");
sb.append(encoded);
sb.append("\r\n");
}
if (pd.requestHeaderLines != null) {
for (int i = 0; i < pd.requestHeaderLines.length; i++) {
if (pd.requestHeaderLines[i] != null) {
sb.append(pd.requestHeaderLines[i]);
sb.append("\r\n");
}
}
}
sb.append("\r\n");
OutputStream out = sock.getOutputStream();
out.write(StringEncoder.GetBytes(sb.toString()));
out.flush();
/* Now parse the HTTP response */
byte[] buffer = new byte[1024];
InputStream in = sock.getInputStream();
int len = ClientServerHello.readLineRN(in, buffer);
String httpReponse = StringEncoder.GetString(buffer, 0, len);
if (httpReponse.startsWith("HTTP/") == false) {
throw new IOException("The proxy did not send back a valid HTTP response.");
}
/* "HTTP/1.X XYZ X" => 14 characters minimum */
if ((httpReponse.length() < 14)
|| (httpReponse.charAt(8) != ' ')
|| (httpReponse.charAt(12) != ' ')) {
throw new IOException("The proxy did not send back a valid HTTP response.");
}
int errorCode = 0;
try {
errorCode = Integer.parseInt(httpReponse.substring(9, 12));
} catch (NumberFormatException ignore) {
throw new IOException("The proxy did not send back a valid HTTP response.");
}
if ((errorCode < 0) || (errorCode > 999)) {
throw new IOException("The proxy did not send back a valid HTTP response.");
}
if (errorCode != 200) {
throw new HTTPProxyException(httpReponse.substring(13), errorCode);
}
/* OK, read until empty line */
while (true) {
len = ClientServerHello.readLineRN(in, buffer);
if (len == 0) {
break;
}
}
return;
}
throw new IOException("Unsupported ProxyData");
}
/** @return Returns the client_versioncomment. */
public byte[] getClientString() {
return StringEncoder.GetBytes(client_line);
}
/** @return Returns the server_versioncomment. */
public byte[] getServerString() {
return StringEncoder.GetBytes(server_line);
}