1 /* 2 * Copyright (c) 2006-2011 Christian Plattner. All rights reserved. 3 * Please refer to the LICENSE.txt for licensing details. 4 */ 5 package ch.ethz.ssh2.transport; 6 7 import java.io.IOException; 8 import java.io.InputStream; 9 import java.io.OutputStream; 10 11 import ch.ethz.ssh2.util.StringEncoder; 12 13 /** 14 * ClientServerHello. 15 * 16 * @author Christian Plattner 17 * @version $Id: ClientServerHello.java 33 2011-05-28 21:59:37Z dkocher (at) sudo.ch $ 18 */ 19 public class ClientServerHello 20 { 21 String server_line; 22 String client_line; 23 24 String server_versioncomment; 25 26 public static int readLineRN(InputStream is, byte[] buffer) throws IOException 27 { 28 int pos = 0; 29 boolean need10 = false; 30 int len = 0; 31 while (true) 32 { 33 int c = is.read(); 34 if (c == -1) 35 throw new IOException("Premature connection close"); 36 37 buffer[pos++] = (byte) c; 38 39 if (c == 13) 40 { 41 need10 = true; 42 continue; 43 } 44 45 if (c == 10) 46 break; 47 48 if (need10 == true) 49 throw new IOException("Malformed line sent by the server, the line does not end correctly."); 50 51 len++; 52 if (pos >= buffer.length) 53 throw new IOException("The server sent a too long line."); 54 } 55 56 return len; 57 } 58 59 public ClientServerHello(String identification, InputStream bi, OutputStream bo) throws IOException 60 { 61 client_line = "SSH-2.0-" + identification; 62 63 bo.write(StringEncoder.GetBytes(client_line + "\r\n")); 64 bo.flush(); 65 66 byte[] serverVersion = new byte[512]; 67 68 for (int i = 0; i < 50; i++) 69 { 70 int len = readLineRN(bi, serverVersion); 71 72 server_line = StringEncoder.GetString(serverVersion, 0, len); 73 74 if (server_line.startsWith("SSH-")) 75 break; 76 } 77 78 if (server_line.startsWith("SSH-") == false) 79 throw new IOException( 80 "Malformed server identification string. There was no line starting with 'SSH-' amongst the first 50 lines."); 81 82 if (server_line.startsWith("SSH-1.99-")) 83 server_versioncomment = server_line.substring(9); 84 else if (server_line.startsWith("SSH-2.0-")) 85 server_versioncomment = server_line.substring(8); 86 else 87 throw new IOException("Server uses incompatible protocol, it is not SSH-2 compatible."); 88 } 89 90 /** 91 * @return Returns the client_versioncomment. 92 */ 93 public byte[] getClientString() 94 { 95 return StringEncoder.GetBytes(client_line); 96 } 97 98 /** 99 * @return Returns the server_versioncomment. 100 */ 101 public byte[] getServerString() 102 { 103 return StringEncoder.GetBytes(server_line); 104 } 105 } 106
