C

SSH Tunnel (Port Forwarding via direct-tcpip channel)

See more SSH Examples

Demonstrates how to create an SSH tunnel to a remote hostname:port via a direct-tcpip channel. C

#include <C_CkSsh.h>

void ChilkatSample(void)
    {
    BOOL success;
    HCkSsh ssh;
    const char *hostname;
    int port;
    int channelNum;
    const char *httpReq;
    BOOL caseSensitive;
    const char *matchStr;
    const char *responseHeader;
    int numBytesRead;
    int pollTimeoutMs;
    const char *htmlBody;

    success = FALSE;

    // This example assumes the Chilkat API to have been previously unlocked.
    // See Global Unlock Sample for sample code.

    ssh = CkSsh_Create();

    // Connect to an SSH server:

    // Hostname may be an IP address or hostname:
    hostname = "192.168.1.117";
    port = 22;

    success = CkSsh_Connect(ssh,hostname,port);
    if (success != TRUE) {
        printf("%s\n",CkSsh_lastErrorText(ssh));
        CkSsh_Dispose(ssh);
        return;
    }

    // Wait a max of 5 seconds when reading responses..
    CkSsh_putIdleTimeoutMs(ssh,5000);

    // Authenticate using login/password:
    success = CkSsh_AuthenticatePw(ssh,"chilkat","myPassword");
    if (success != TRUE) {
        printf("%s\n",CkSsh_lastErrorText(ssh));
        CkSsh_Dispose(ssh);
        return;
    }

    // Open a direct-tcpip channel.  We want the SSH server to connect
    // to www.chilkatsoft.com, port 80 (i.e. the web server).
    // Data sent through the SSH tunnel is forwarded to the remote
    // host:port.  (Note: The remote host:port does not need to be 
    // a web server.  It can be anything.  It can be your own
    // customer application server that listens on a port, or any
    // other type of server.)
    // When we read from the SSH channel, we'll be reading data
    // sent from the remote host:port (i.e. the web server in this
    // example).

    channelNum = CkSsh_OpenDirectTcpIpChannel(ssh,"www.chilkatsoft.com",80);
    if (channelNum < 0) {
        printf("%s\n",CkSsh_lastErrorText(ssh));
        CkSsh_Dispose(ssh);
        return;
    }

    // Build a simple HTTP GET request for http://www.chilkatsoft.com/xyz.html
    httpReq = "GET /xyz123.html HTTP/1.1\r\nHost: www.chilkatsoft.com\r\n\r\n";

    // Send the HTTP request:
    success = CkSsh_ChannelSendString(ssh,channelNum,httpReq,"ansi");
    if (success != TRUE) {
        printf("%s\n",CkSsh_lastErrorText(ssh));
        CkSsh_Dispose(ssh);
        return;
    }

    // Get the HTTP response.
    // First read the HTTP response header which ends with a double CRLF.
    // Calling ChannelReceiveUntilMatch will receive until match string is seen,
    // or until a timeout occurs (IdleTimeoutMs property).  ChannelReceiveUntilMatch
    // may read beyond the match string, but it will stop reading as soon as the match
    // string is seen.
    caseSensitive = FALSE;
    matchStr = "\r\n\r\n";
    success = CkSsh_ChannelReceiveUntilMatch(ssh,channelNum,matchStr,"ansi",caseSensitive);
    if (success != TRUE) {
        printf("%s\n",CkSsh_lastErrorText(ssh));
        CkSsh_Dispose(ssh);
        return;
    }

    // Extract the HTTP header from the receive buffer.
    // (GetReceiveTextS extracts up to and including the match string from the receive buffer)

    responseHeader = CkSsh_getReceivedTextS(ssh,channelNum,matchStr,"ansi");
    printf("---- HTTP Response Header ----\n");
    printf("%s\n",responseHeader);

    // Now get the body of the HTTP response (this is the HTML content
    // of http://www.chilkatsoft.com/xyz.html
    // It's possible we've already received the entire HTTP response in the
    // call to ChannelReceiveUntilMatch.  Therefore, we'll poll for any remaining data
    // and wait a max of .2 seconds.

    pollTimeoutMs = 200;
    numBytesRead = CkSsh_ChannelPoll(ssh,channelNum,pollTimeoutMs);
    // We're not checking for an error here.
    // A return value of -2 means that no data was available and the poll simply timed out (not an error)
    // A return value of -1 indicates an error.
    // A return value greater than 0 indicates that additional data was received.

    printf("---- HTML BODY ----\n");

    // Extract the remainder of the accumulated data in the internal receive buffer.
    // This should be our HTML body:

    htmlBody = CkSsh_getReceivedText(ssh,channelNum,"ansi");
    printf("%s\n",htmlBody);

    // Close the channel:
    success = CkSsh_ChannelSendClose(ssh,channelNum);
    if (success != TRUE) {
        printf("%s\n",CkSsh_lastErrorText(ssh));
        CkSsh_Dispose(ssh);
        return;
    }

    // Disconnect
    CkSsh_Disconnect(ssh);


    CkSsh_Dispose(ssh);

    }