kdesu/ssh.cpp

   1 /* vi: ts=8 sts=4 sw=4
   2 *
   3 * This file is part of the KDE project, module kdesu.
   4 * Copyright (C) 2000 Geert Jansen <jansen@kde.org>
   5 *
   6 * This is free software; you can use this library under the GNU Library
   7 * General Public License, version 2. See the file "COPYING.LIB" for the
   8 * exact licensing terms.
   9 *
  10 * ssh.cpp: Execute a program on a remote machine using ssh.
  11 */
  12
  13 #include "ssh.h"
  14 #include "kcookie.h"
  15
  16 #include <config.h>
  17
  18 #include <stdio.h>
  19 #include <stdlib.h>
  20 #include <unistd.h>
  21 #include <fcntl.h>
  22 #include <signal.h>
  23 #include <errno.h>
  24 #include <string.h>
  25 #include <ctype.h>
  26 #include <time.h>
  27
  28 #include <sys/types.h>
  29 #include <sys/stat.h>
  30
  31 #include <QtCore/QBool>
  32
  33 #include <kdebug.h>
  34 #include <klocale.h>
  35 #include <kstandarddirs.h>
  36
  37 namespace KDESu {
  38
  39 using namespace KDESuPrivate;
  40
  41 class SshProcess::SshProcessPrivate
  42 {
  43 public:
  44     SshProcessPrivate(const QByteArray &host)
  45         : m_Host( host )
  46         , m_Stub( "kdesu_stub" )
  47     {}
  48     QByteArray m_Prompt;
  49     QByteArray m_Host;
  50     QByteArray m_Error;
  51     QByteArray m_Stub;
  52 };
  53
  54
  55 SshProcess::SshProcess(const QByteArray &host, const QByteArray &user, const QByteArray &command)
  56     : d( new SshProcessPrivate(host) )
  57 {
  58     m_User = user;
  59     m_Command = command;
  60     srand(time(0L));
  61 }
  62
  63
  64 SshProcess::~SshProcess()
  65 {
  66     delete d;
  67 }
  68
  69 void SshProcess::setHost(const QByteArray &host)
  70 {
  71     d->m_Host = host;
  72 }
  73
  74
  75 void SshProcess::setStub(const QByteArray &stub)
  76 {
  77     d->m_Stub = stub;
  78 }
  79
  80
  81 int SshProcess::checkInstall(const char *password)
  82 {
  83     return exec(password, 1);
  84 }
  85
  86
  87 int SshProcess::checkNeedPassword()
  88 {
  89     return exec(0L, 2);
  90 }
  91
  92
  93 int SshProcess::exec(const char *password, int check)
  94 {
  95     if (check)
  96     setTerminal(true);
  97
  98     QList<QByteArray> args;
  99     args += "-l"; args += m_User;
 100     args += "-o"; args += "StrictHostKeyChecking=no";
 101     args += d->m_Host; args += d->m_Stub;
 102
 103     if (StubProcess::exec("ssh", args) < 0)
 104     {
 105         return check ? SshNotFound : -1;
 106     }
 107
 108     int ret = ConverseSsh(password, check);
 109     if (ret < 0)
 110     {
 111         if (!check)
 112             kError(900) << k_lineinfo << "Conversation with ssh failed\n";
 113         return ret;
 114     }
 115     if (check == 2)
 116     {
 117         if (ret == 1)
 118         {
 119             kill(m_Pid, SIGTERM);
 120             waitForChild();
 121         }
 122         return ret;
 123     }
 124
 125     if (m_bErase && password)
 126         memset(const_cast<char *>(password), 0, qstrlen(password));
 127
 128     ret = ConverseStub(check);
 129     if (ret < 0)
 130     {
 131         if (!check)
 132             kError(900) << k_lineinfo << "Conversation with kdesu_stub failed\n";
 133         return ret;
 134     }
 135     else if (ret == 1)
 136     {
 137         kill(m_Pid, SIGTERM);
 138         waitForChild();
 139         ret = SshIncorrectPassword;
 140     }
 141
 142     if (check == 1)
 143     {
 144         waitForChild();
 145         return 0;
 146     }
 147
 148     setExitString("Waiting for forwarded connections to terminate");
 149     ret = waitForChild();
 150     return ret;
 151 }
 152
 153 QByteArray SshProcess::prompt() const
 154 {
 155     return d->m_Prompt;
 156 }
 157
 158 QByteArray SshProcess::error() const
 159 {
 160     return d->m_Error;
 161 }
 162
 163
 164 /*
 165 * Conversation with ssh.
 166 * If check is 0, this waits for either a "Password: " prompt,
 167 * or the header of the stub. If a prompt is received, the password is
 168 * written back. Used for running a command.
 169 * If check is 1, operation is the same as 0 except that if a stub header is
 170 * received, the stub is stopped with the "stop" command. This is used for
 171 * checking a password.
 172 * If check is 2, operation is the same as 1, except that no password is
 173 * written. The prompt is saved to m_Prompt. Used for checking the need for
 174 * a password.
 175 */
 176
 177 int SshProcess::ConverseSsh(const char *password, int check)
 178 {
 179     unsigned i, j, colon;
 180
 181     QByteArray line;
 182     int state = 0;
 183
 184     while (state < 2)
 185     {
 186         line = readLine();
 187         const uint len = line.length();
 188         if (line.isNull())
 189             return -1;
 190
 191         switch (state) {
 192         case 0:
 193             // Check for "kdesu_stub" header.
 194             if (line == "kdesu_stub")
 195             {
 196                 unreadLine(line);
 197                 return 0;
 198             }
 199
 200             // Match "Password: " with the regex ^[^:]+:[\w]*$.
 201             for (i=0,j=0,colon=0; i<len; i++)
 202             {
 203                 if (line[i] == ':')
 204                 {
 205                     j = i; colon++;
 206                     continue;
 207                 }
 208                 if (!isspace(line[i]))
 209                     j++;
 210             }
 211             if ((colon == 1) && (line[j] == ':'))
 212             {
 213                 if (check == 2)
 214                 {
 215                     d->m_Prompt = line;
 216                     return SshNeedsPassword;
 217                 }
 218                 WaitSlave();
 219                 write(fd(), password, strlen(password));
 220                 write(fd(), "\n", 1);
 221                 state++;
 222                 break;
 223             }
 224
 225             // Warning/error message.
 226             d->m_Error += line; d->m_Error += '\n';
 227             if (m_bTerminal)
 228                 fprintf(stderr, "ssh: %s\n", line.constData());
 229             break;
 230
 231         case 1:
 232             if (line.isEmpty())
 233             {
 234                 state++;
 235                 break;
 236             }
 237             return -1;
 238         }
 239     }
 240     return 0;
 241 }
 242
 243
 244 // Display redirection is handled by ssh natively.
 245 QByteArray SshProcess::display()
 246 {
 247     return "no";
 248 }
 249
 250
 251 QByteArray SshProcess::displayAuth()
 252 {
 253     return "no";
 254 }
 255
 256 void SshProcess::virtual_hook( int id, void* data )
 257 { StubProcess::virtual_hook( id, data ); }
 258
 259 }