¿Cómo establecer fácilmente una conexión SSH en Qt?

Question

Estoy buscando una manera fácil de establecer una conexión ssh en Qt similar a cómo puedo operar en Java.

Por ejemplo, para conectarse a una conexión SSH a través de Java, que puedo hacer:

import com.sshtools.j2ssh.SshClient; 
import com.sshtools.j2ssh.transport.IgnoreHostKeyVerification; 
import com.sshtools.j2ssh.authentication.PasswordAuthenticationClient; 
import com.sshtools.j2ssh.authentication.AuthenticationProtocolState; 

...... 

    SshClient ssh = new SshClient(); 
    try { 
     // Timeout of ten seconds 
     ssh.setSocketTimeout(10*1000); 
     ssh.connect(ip, port, new IgnoreHostKeyVerification()); 

     PasswordAuthenticationClient auth = new PasswordAuthenticationClient(); 
     auth.setUsername(username); 
     auth.setPassword(password); 

     if (ssh.authenticate(auth) != AuthenticationProtocolState.COMPLETE) { 
      errorLabel.setForeground(Color.RED); 
      errorLabel.setText("Username or password is incorrect"); 
     } 
     else 
      successful = true; 
    } 
    catch (Exception e) { 
     errorLabel.setForeground(Color.RED); 
     errorLabel.setText("Cannot log into website"); 
     e.printStackTrace(); 
    } 

Las soluciones que he visto para Qt son:

1. rueda mi propio uso de libssh
2. rueda mi propio uso de libssh2
3. uso QProcess para llamar a un proceso de SSH exterior para establecer una conexión
4. Comprar el biblioteca aquí: http://netsieben.com/products/ssh/

Desde la versión Java es libre, yo soy un poco reacio a gastar dinero en esto, pero si tengo que hacerlo, tengo que hacerlo. Prefiero no hacer las mías, porque solo puedo ver que sea una causa de errores (a menos que esas bibliotecas sean fáciles de usar).

¿Alguna cosa que no haya encontrado?

EDIT: he pasado días luchando con libssh y libqxt. Ambas son fallas absolutas en Windows, por lo que puedo determinar. Libqxt no se compilará en Windows con ssh, incluso después de seguir los pasos descritos here y here. La clase contenedora C++ de Libssh incluye todo en el encabezado, lo que está causando fallas de enlace si no se supervisa cuidadosamente. Una vez resueltos los problemas del enlazador, la biblioteca compilada de Libssh bloquea el CDB, por lo que la depuración con libssh se vuelve imposible, independientemente de si se utiliza o no el envoltorio de C++. Así que ahora estoy de vuelta a libssh2 o pagando a través de algún programa dudoso que aparentemente no se ha actualizado en cuatro años. Cryptlib, tal vez? No ayuda que la mayor parte de la ayuda del foro qt parezca 'engendrar otro proceso', que por lo tanto requiere que mis usuarios tengan instalado ssh, lo cual definitivamente no es el par del curso en Windows.

Answer 1

Ver LibQxt. Busque las clases QxtSsh. hg repo usando libssh2 internamente.

Answer 2

He buscado algún tipo de solución para esto durante un par de días y luego me olvidé del problema. Entonces hoy tropecé con esta pequeña joya en la fuente de Qt-Creator Utils::ssh, incluye soporte para SFTP, SSH simple y todo tipo de cosas.

Desenredándose cosas de Qt Creator puede ser un dolor, pero después de haber pasado por este proceso equivale a agarrar Botan (una de las otras librerías QT-creador) + Utilidades de

Answer 3

He aquí un asíncrono ssh & SCP "socket" que escribí para Qt que es multiplataforma. Esto requiere libSSH y no es perfecto (oculta el paso de la clave rsa, ofrece respuestas de comando en una sola toma en lugar de a través de las señales de readyRead), pero lo más probable es que funcione para sus necesidades. Para que esto funcione en Windows, este archivo debe ser el PRIMER archivo incluido en su proyecto (para que qt no intente e importe windows.h antes de que pueda importar el código de socket de Windows correcto).

Cabecera:

#ifndef QSSHSOCKET_H 
#define QSSHSOCKET_H 

#include <libssh/libssh.h> 
#include <QByteArray> 
#include <QThread> 
#include <QVector> 
#include <QFile> 
#include <sys/stat.h> 
#include <sys/types.h> 
#include <QDebug> 

class QSshSocket: public QThread 
{ 
    Q_OBJECT 
public: 

    enum SshError 
    { 
     /*! \brief There was trouble creating a socket. This was most likely due to the lack of an internet connection.*/ 
     SocketError, 
     /*! \brief The ssh session could not be created due to inability to find the remote host.*/ 
     SessionCreationError, 
     /*! \brief An ssh channel could not be created for the previous operation.*/ 
     ChannelCreationError, 
     /*! \brief An scp channel could not be created for the previous file transfer operation.*/ 
     ScpChannelCreationError, 
     /*! \brief There was an error requesting a pull file transfer.*/ 
     ScpPullRequestError, 
     /*! \brief There was an error requesting a push file transfer.*/ 
     ScpPushRequestError, 
     /*! \brief The destination file for the previous transfer does not exist.*/ 
     ScpFileNotCreatedError, 
     /*! \brief There was an error reading a remote file. This could possibly be due to user permissions.*/ 
     ScpReadError, 
     /*! \brief There was an error writing to a remote file. This could possibly be due to user permissions.*/ 
     ScpWriteError, 
     /*! \brief The credentials of a user on the remote host could not be authenticated.*/ 
     PasswordAuthenticationFailedError 
    }; 

    /*! 
     \param position The center position of the box. 
     \param size The size of the box. 
     \brief The constructor. 
    */ 
    explicit QSshSocket(QObject * parent = 0); 

    /*! 
     \brief The deconstructor. 
    */ 
    ~QSshSocket(); 

    /*! 
     \param host The hostname to establish an ssh connection with. 
     \param port The port to establish an ssh connection over. 
     \brief This function connects this socket to the specified host over the specified port. On success, the signal connected is emitted while error is emmited on failure. 
    */ 
    void connectToHost(QString host, int port =22); 

    /*! 
     \brief This function disconnects the socket from the current host (if there is one. On success, the signal disconnected is emitted while error is emmited on failure. 
    */ 
    void disconnectFromHost(); 

    /*! 
     \param command The command to be executed. 
     \brief This function executes a remote command on the connected host. If not connected to a remote host, the command is not executed. 
     On success, the signal commandExecuted is emitted while error is emmited on failure. 
    */ 
    void executeCommand(QString command); 

    /*! 
     \brief Returns the hostname of the remote machine this socket is connected to. If not connected to a remote host, this returns "". 
    */ 
    QString host(); 

    /*! 
     \brief Returns whether or not a user has been logged in at remote host. 
    */ 
    bool isLoggedIn(); 

    /*! 
     \brief Returns whether or not this socket is currently connected to a remote host. 
    */ 
    bool isConnected(); 

    /*! 
     \param user The username to login with. 
     \param password The password of the account for the specified username. 
     \brief This function to login to the currently connected host given credentials. 
     On success, the signal authenticated is emitted while error is emmited on failure. 
    */ 
    void login(QString user, QString password); 

    /*! 
     \brief Returns the port of the current connection. If not connected to a remote host, this returns -1. 
    */ 
    int port(); 

    /*! 
     \param localPath A path to a file stored on the local machine. 
     \param password A path to a file stored on the remote machine. 
     \brief This function attempts to pull a remote file from the connected host to a local file. The local file does not need to be created beforehand. 
     On success, the signal pullSuccessful is emitted while error is emmited on failure. 
     If not connected to a remote host, or if the transfer was unsuccessful, the signal error is emitted. 
    */ 
    void pullFile(QString localPath, QString remotePath); 

    /*! 
     \param localPath A path to a file stored on the local machine. 
     \param password A path to a file stored on the remote machine. 
     \brief This function attempts to pull a remote file from the connected host to a local file. The local file does not need to be created beforehand. 
     On success, the signal pushSuccessful is emitted while error is emmited on failure. 
     If not connected to a remote host, or if the transfer was unsuccessful, the signal error is emitted. 
    */ 
    void pushFile(QString localPath, QString remotePath); 

    /*! 
     \param path A relative or absolute path to a directory on the remote host. 
     \brief This function attempts to set the working directory of the connection to path and emits workingDirectorySet upon completion. 
     If workingDirectorySet indicates no change in the working directory, the path could not be found. 
     If not connected to a remote host the signal error will be emitted. 
    */ 
    void setWorkingDirectory(QString path); 

    /*! 
     \brief Returns the username of the current authenticated user on the remote host. If not connected to a remote host, or if a user has not been authenticated this returns "". 
    */ 
    QString user(); 



signals: 

    /*! 
     \brief This signal is emitted when remote host has been connected to." 
    */ 
    void connected(); 

    /*! 
     \brief This signal is emitted when this class has been properly disconnected from a remote host. 
    */ 
    void disconnected(); 

    /*! 
     \param error The type of error that occured. 
     \brief This signal is emitted when an error occurs. 
    */ 
    void error(QSshSocket::SshError error); 

    /*! 
     \param command The command that was executed on the remote host. 
     \param response The response to the command that was executed. 
     \brief This signal is emitted when a response from the remote host is received regarding a command. 
    */ 
    void commandExecuted(QString command,QString response); 

    /*! 
     \brief This signal is emitted when a user has been loggen in to the remote host." 
    */ 
    void loginSuccessful(); 

    /*! 
     \param localFile The path to a local file that the remote file was pulled to. 
     \param remoteFile The path to a file pulled from the remote host. 
     \brief This signal is emitted when a remote file is successfully transfered to a local file. 
    */ 
    void pullSuccessful(QString localFile, QString remoteFile); 

    /*! 
     \param localFile The path to a local file pushed to the remote host. 
     \param remoteFile The path to a remote file that the local file was pushed to. 
     \brief This signal is emitted when a local file is successfully transfered to a remote file. 
    */ 
    void pushSuccessful(QString localFile, QString remoteFile); 

    /*! 
     \param cwd The current working directory of the session on the remote host. 
     \brief This signal is emitted when a current working directory is set. 
    */ 
    void workingDirectorySet(QString cwd); 

private slots: 
    void run(); 

private: 

    enum SSHOperationType 
    { 
     Command, 
     WorkingDirectoryTest, 
     Pull, 
     Push 
    }; 

    struct SSHOperation 
    { 
     SSHOperationType type; 
     QString adminCommand,command, localPath, remotePath; 
     bool executed; 
    }; 

    int m_port; 
    bool m_loggedIn ; 
    QThread * m_thread; 
    QString m_workingDirectory,m_nextWorkingDir,m_user, m_host,m_password; 
    SSHOperation m_currentOperation; 
    ssh_session m_session; 
    bool m_connected,m_run; 
}; 


#endif // QSSHSOCKET_H 

Fuente:

#include "qsshsocket.h" 
#include <QFileInfo> 
// if compiling in windows, add needed flags. 
#ifdef _WIN32 
# include <io.h> 

typedef int mode_t; 

/// @Note If STRICT_UGO_PERMISSIONS is not defined, then setting Read for any 
///  of User, Group, or Other will set Read for User and setting Write 
///  will set Write for User. Otherwise, Read and Write for Group and 
///  Other are ignored. 
/// 
/// @Note For the POSIX modes that do not have a Windows equivalent, the modes 
///  defined here use the POSIX values left shifted 16 bits. 

static const mode_t S_ISUID  = 0x08000000;   ///< does nothing 
static const mode_t S_ISGID  = 0x04000000;   ///< does nothing 
static const mode_t S_ISVTX  = 0x02000000;   ///< does nothing 
static const mode_t S_IRUSR  = mode_t(_S_IREAD);  ///< read by user 
static const mode_t S_IWUSR  = mode_t(_S_IWRITE); ///< write by user 
static const mode_t S_IXUSR  = 0x00400000;   ///< does nothing 
# ifndef STRICT_UGO_PERMISSIONS 
static const mode_t S_IRGRP  = mode_t(_S_IREAD);  ///< read by *USER* 
static const mode_t S_IWGRP  = mode_t(_S_IWRITE); ///< write by *USER* 
static const mode_t S_IXGRP  = 0x00080000;   ///< does nothing 
static const mode_t S_IROTH  = mode_t(_S_IREAD);  ///< read by *USER* 
static const mode_t S_IWOTH  = mode_t(_S_IWRITE); ///< write by *USER* 
static const mode_t S_IXOTH  = 0x00010000;   ///< does nothing 
# else 
static const mode_t S_IRGRP  = 0x00200000;   ///< does nothing 
static const mode_t S_IWGRP  = 0x00100000;   ///< does nothing 
static const mode_t S_IXGRP  = 0x00080000;   ///< does nothing 
static const mode_t S_IROTH  = 0x00040000;   ///< does nothing 
static const mode_t S_IWOTH  = 0x00020000;   ///< does nothing 
static const mode_t S_IXOTH  = 0x00010000;   ///< does nothing 
# endif 
static const mode_t MS_MODE_MASK = 0x0000ffff;   ///< low word 
#endif 


QSshSocket::QSshSocket(QObject * parent) 
    :QThread(parent) 
{ 
    m_host = ""; 
    m_user = ""; 
    m_password = ""; 
    m_port = -1; 
    m_loggedIn = false; 
    m_session = NULL; 
    m_workingDirectory = "."; 

    qRegisterMetaType<QSshSocket::SshError>("QSshSocket::SshError"); 
    m_currentOperation.executed = true; 

    m_run = true; 
    start(); 
} 

QSshSocket::~QSshSocket() 
{ 
    m_run = false; 
    this->wait(); 
} 

void QSshSocket::run() 
{ 

    while(m_run) 
    { 
     if (m_session == NULL) 
     { 
      if (m_host != "") 
      { 
       m_session = ssh_new(); 

       //set logging to verbose so all errors can be debugged if crash happens 
       int verbosity = SSH_LOG_PROTOCOL; 

       // set the pertinant ssh session options 
       ssh_options_set(m_session, SSH_OPTIONS_HOST, m_host.toAscii().data()); 
       ssh_options_set(m_session, SSH_OPTIONS_USER, m_user.toAscii().data()); 
       ssh_options_set(m_session, SSH_OPTIONS_LOG_VERBOSITY, &verbosity); 
       ssh_options_set(m_session, SSH_OPTIONS_PORT, &m_port); 

       // try to connect given host, user, port 
       int connectionResponse = ssh_connect(m_session); 

       // if connection is Successful keep track of connection info. 
       if (connectionResponse == SSH_OK) 
        connected(); 

       else 
        error(SessionCreationError); 

      } 

     } 


     // if we have a vaild ssh connection, authenticate connection with credentials 
     else if (!m_loggedIn) 
     { 


      // check to see if a username and a password have been given 
      if (m_user != "" && m_password !="") 
      { 

       // try authenticating current user at remote host 
       int worked = ssh_userauth_password(m_session, m_user.toAscii().data(), m_password.toAscii().data()); 


       // if successful, store user password. 
       if (worked == SSH_OK) 
       { 
        loginSuccessful(); 
        m_loggedIn = true; 
       } 
       else 
       { 
        m_user = ""; 
        m_password = ""; 
        error(PasswordAuthenticationFailedError); 
       } 


      } 
     } 
     // if all ssh setup has been completed, check to see if we have any commands to execute 
     else if (!m_currentOperation.executed) 
     { 

      if (m_currentOperation.type == Command || m_currentOperation.type == WorkingDirectoryTest) 
      { 
       // attempt to open ssh shell channel 
       ssh_channel channel = ssh_channel_new(m_session); 

       // if attempt fails,return 
       if (ssh_channel_open_session(channel) != SSH_OK) 
       { 
        error(ChannelCreationError); 
       } 


       int requestResponse = SSH_AGAIN; 

       // attempt to execute shell command 
       while (requestResponse == SSH_AGAIN) 
        requestResponse = ssh_channel_request_exec(channel, m_currentOperation.adminCommand.toAscii().data()); 

       // if attempt not executed, close connection then return 
       if (requestResponse != SSH_OK) 
       { 
        error(ChannelCreationError); 
       } 


       QByteArray buffer; 
       buffer.resize(1000); 

       // read in command result 
       int totalBytes = 0, newBytes = 0; 
       do 
       { 
        newBytes = ssh_channel_read(channel, &(buffer.data()[totalBytes]), buffer.size() - totalBytes, 0); 
        if (newBytes > 0) 
         totalBytes += newBytes; 
       }while (newBytes > 0); 

       // close channel 
       ssh_channel_send_eof(channel); 
       ssh_channel_close(channel); 
       ssh_channel_free(channel); 

       QString response = QString(buffer).mid(0,totalBytes); 
       response.replace("\n",""); 
       if (m_currentOperation.type == WorkingDirectoryTest) 
       { 
        if (response == "exists") 
         m_workingDirectory = m_nextWorkingDir; 
        m_nextWorkingDir = "."; 
        workingDirectorySet(m_workingDirectory); 
       } 
       else 
        commandExecuted(m_currentOperation.command, response) ; 

      } 
      // if all ssh setup has been completed, check to see if we have any file transfers to execute 
      else if (m_currentOperation.type == Pull) 
      { 
       ssh_scp scpSession = ssh_scp_new(m_session,SSH_SCP_READ, m_currentOperation.remotePath.toAscii().data()); 
       if (scpSession == NULL) 
        error(ScpChannelCreationError); 

       // attempt to initialize new scp session. 
       int scpInitialized = ssh_scp_init(scpSession); 
       if(scpInitialized != SSH_OK) 
       { 
        ssh_scp_close(scpSession); 
        ssh_scp_free(scpSession); 
        error(ScpChannelCreationError); 
       } 


       // attempt to authorize new scp pull 
       if (ssh_scp_pull_request(scpSession) != SSH_SCP_REQUEST_NEWFILE) 
       { 
        ssh_scp_close(scpSession); 
        ssh_scp_free(scpSession); 
        error(ScpPullRequestError); 
       } 

       // accept authorization 
       ssh_scp_accept_request(scpSession); 


       // get remote file size 
       int size = ssh_scp_request_get_size(scpSession); 

       // resize buffer, read remote file into buffer 
       QByteArray buffer; 
       buffer.resize(size); 

       // if an error happens while reading, close the scp session and return 
       if (ssh_scp_read(scpSession, buffer.data() , size) == SSH_ERROR) 
       { 
        ssh_scp_close(scpSession); 
        ssh_scp_free(scpSession); 
        error(ScpReadError); 
       } 

       // loop until eof flag 
       if (ssh_scp_pull_request(scpSession) != SSH_SCP_REQUEST_EOF) 
       { 
        ssh_scp_close(scpSession); 
        ssh_scp_free(scpSession); 
        error(ScpReadError); 
       } 

       //close scp session 
       ssh_scp_close(scpSession); 
       ssh_scp_free(scpSession); 

       // open up local file and write contents of buffer to it. 
       QFile file(m_currentOperation.localPath); 
       file.open(QIODevice::WriteOnly); 
       file.write(buffer); 
       file.close(); 

       pullSuccessful(m_currentOperation.localPath,m_currentOperation.remotePath); 

      } 
      else if (m_currentOperation.type == Push) 
      { 
       // attempt to create new scp from ssh session. 
       ssh_scp scpSession = ssh_scp_new(m_session,SSH_SCP_WRITE, m_currentOperation.remotePath.toAscii().data()); 

       // if creation failed, return 
       if (scpSession == NULL) 
        error(SocketError); 


       // attempt to initialize new scp session. 
       int scpInitialized = ssh_scp_init(scpSession); 


       // if failed, close scp session and return. 
       if(scpInitialized != SSH_OK) 
       { 
        ssh_scp_close(scpSession); 
        ssh_scp_free(scpSession); 
        error(ScpChannelCreationError); 
       } 


       // open the local file and check to make sure it exists 
       // if not, close scp session and return. 
       QFile file(m_currentOperation.localPath); 
       if (!file.exists()) 
       { 
        ssh_scp_close(scpSession); 
        ssh_scp_free(scpSession); 
        error(ScpFileNotCreatedError); 
       } 

       // if the file does exist, read all contents as bytes 
       file.open(QIODevice::ReadOnly); 
       QByteArray buffer =file.readAll(); 
       file.close(); 

       // attempt to authorize pushing bytes over scp socket 
       // if this fails, close scp session and return. 
       if (ssh_scp_push_file(scpSession, m_currentOperation.remotePath.toAscii().data(), buffer.size(), S_IRUSR | S_IWUSR) != SSH_OK) 
       { 
        ssh_scp_close(scpSession); 
        ssh_scp_free(scpSession); 
        error(ScpPushRequestError); 
       } 


       // once authorized to push bytes over scp socket, start writing 
       // if an error is returned, close scp session and return. 
       if (ssh_scp_write(scpSession,buffer.data(), buffer.size()) != SSH_OK) 
       { 

        ssh_scp_close(scpSession); 
        ssh_scp_free(scpSession); 
        error(ScpWriteError); 
       } 


       // close scp session and return. 
       ssh_scp_close(scpSession); 
       ssh_scp_free(scpSession); 

       pushSuccessful(m_currentOperation.localPath,m_currentOperation.remotePath); 

      } 


      m_currentOperation.executed = true; 
     } 
     else 
     { 
      msleep(100); 
     } 

    } 

} 
void QSshSocket::disconnectFromHost() 
{ 
    m_host = ""; 
    m_user = ""; 
    m_password = ""; 
    m_port = -1; 
    m_loggedIn = false; 
    if (m_session != NULL) 
    { 
     ssh_disconnect(m_session); 
     ssh_free(m_session); 
    } 
    m_session = NULL; 
} 

void QSshSocket::connectToHost(QString host, int port) 
{ 
    m_host = host; 
    m_port = port; 
} 
void QSshSocket::login(QString user, QString password) 
{ 
    m_user = user; 
    m_password = password; 
} 
void QSshSocket::executeCommand(QString command) 
{ 
    m_currentOperation.type = Command; 
    if (m_workingDirectory != ".") 
     m_currentOperation.adminCommand = "cd " + m_workingDirectory + "; " + command; 
    else 
     m_currentOperation.adminCommand = command ; 

    m_currentOperation.command =command; 
    m_currentOperation.executed = false; 
} 

void QSshSocket::pullFile(QString localPath, QString remotePath) 
{ 
    m_currentOperation.localPath = localPath; 
    if (QFileInfo(remotePath).isAbsolute()) 
     m_currentOperation.remotePath = remotePath; 
    else 
     m_currentOperation.remotePath = m_workingDirectory + "/" + remotePath; 
    m_currentOperation.type = Pull; 
    m_currentOperation.executed = false; 
} 

void QSshSocket::pushFile(QString localPath, QString remotePath) 
{ 
    m_currentOperation.localPath = localPath; 
    if (QFileInfo(remotePath).isAbsolute()) 
     m_currentOperation.remotePath = remotePath; 
    else 
     m_currentOperation.remotePath = m_workingDirectory + "/" + remotePath; 
    m_currentOperation.type = Push; 
    m_currentOperation.executed = false; 
} 

void QSshSocket::setWorkingDirectory(QString path) 
{ 
    m_nextWorkingDir = path; 
    m_currentOperation.type = WorkingDirectoryTest; 
    m_currentOperation.adminCommand = "[ -d " + m_nextWorkingDir +" ] && echo 'exists'"; 
    m_currentOperation.executed = false; 
} 

bool QSshSocket::isConnected() 
{ 
    return m_session != NULL; 
} 

bool QSshSocket::isLoggedIn() 
{ 
    return m_loggedIn; 
} 

QString QSshSocket::user(){return m_user;} 
QString QSshSocket::host(){return m_host;} 
int QSshSocket::port(){return m_port;} 

Answer 4

estoy usando libssh2 http://www.libssh2.org/ con Qt. Lo estoy usando de la manera más fácil: enchufes nativos. No tuve tiempo de convertirlo para usar sockets qt. Sin embargo, funciona genial. La descripción del proyecto es: http://www.chaosstuff.com/2013/09/gnome-mplayer-remote-with-qt-and-libssh2.html y el código fuente está en: https://bitbucket.org/nchokoev/qtsshremote