C
C
POP3 SSH Tunneling (Port Forwarding)
Demonstrates how to connect to a POP3 server through an SSH tunnel. Reads a POP3 mailbox and display the FROM and SUBJECT header fields of each email.Chilkat C Downloads
#include <C_CkMailMan.h>
#include <C_CkEmail.h>
void ChilkatSample(void)
{
BOOL success;
HCkMailMan mailman;
const char *sshHostname;
int sshPort;
int numToDownload;
int i;
HCkEmail email;
success = FALSE;
// This example requires the Chilkat API to have been previously unlocked.
// See Global Unlock Sample for sample code.
// The mailman object is used for receiving (POP3)
// and sending (SMTP) email.
mailman = CkMailMan_Create();
// The SSH hostname may be a hostname or an
// IP address, such as "192.168.1.108".
// The port is typically 22 (the standard port for SSH).
sshHostname = "sftp.example.com";
sshPort = 22;
// Connect to an SSH server and establish the SSH tunnel:
success = CkMailMan_SshOpenTunnel(mailman,sshHostname,sshPort);
if (success == FALSE) {
printf("%s\n",CkMailMan_lastErrorText(mailman));
CkMailMan_Dispose(mailman);
return;
}
// Authenticate with the SSH server via a login/password
// or with a public key.
// This example demonstrates SSH password authentication.
// Note: This is not authenticating with the POP3 server, it is
// for authenticating with the SSH server, which is separate.
success = CkMailMan_SshAuthenticatePw(mailman,"ssh_login","ssh_password");
if (success == FALSE) {
printf("%s\n",CkMailMan_lastErrorText(mailman));
CkMailMan_Dispose(mailman);
return;
}
// OK, the SSH tunnel is setup. The mailman may
// be used exactly the same as usual, except all communications
// are now sent through the SSH tunnel.
// The SSH tunnel may be kept open for any number of
// POP3 connections.
// Set the POP3 server's hostname
CkMailMan_putMailHost(mailman,"mail.my-pop3-server.com");
// Set the POP3 settings for your POP3 server:
CkMailMan_putPopUsername(mailman,"pop3_login");
CkMailMan_putPopPassword(mailman,"pop3_password");
CkMailMan_putMailPort(mailman,995);
CkMailMan_putPopSsl(mailman,TRUE);
// Connect to the POP3 server through the already-established SSH tunnel:
success = CkMailMan_Pop3BeginSession(mailman);
if (success == FALSE) {
printf("%s\n",CkMailMan_lastErrorText(mailman));
CkMailMan_Dispose(mailman);
return;
}
// A visual inspection of the LastErrorText after
// a successful POP3 connection will confirm the SSH tunneling.
// Note: If the POP3 connection uses SSL/TLS, then the SSL/TLS
// secure channel will be wrapped within the SSH tunnel.
printf("%s\n",CkMailMan_lastErrorText(mailman));
// How many messages are in the POP3 inbox?
numToDownload = CkMailMan_GetMailboxCount(mailman);
if (numToDownload > 5) {
numToDownload = 5;
}
if (numToDownload == 0) {
printf("No messages in the POP3 inbox.\n");
CkMailMan_Dispose(mailman);
return;
}
// Download a max of 5 messages
email = CkEmail_Create();
for (i = 1; i <= numToDownload; i++) {
success = CkMailMan_FetchOne(mailman,FALSE,0,i,email);
if (success == FALSE) {
printf("%s\n",CkMailMan_lastErrorText(mailman));
CkMailMan_Dispose(mailman);
CkEmail_Dispose(email);
return;
}
printf("%s\n",CkEmail_ck_from(email));
printf("%s\n",CkEmail_subject(email));
printf("----\n");
}
// Close the connection with the POP3 server, leaving the SSH tunnel open for subsequent POP3 connections.
success = CkMailMan_Pop3EndSession(mailman);
if (success == FALSE) {
printf("%s\n",CkMailMan_lastErrorText(mailman));
CkMailMan_Dispose(mailman);
CkEmail_Dispose(email);
return;
}
// Try connecting to a different POP3 server through the same aleady setup SSH tunnel:
// Set the POP3 server's hostname
CkMailMan_putMailHost(mailman,"mail.my-pop3-server2.com");
// Set the POP3 settings for your POP3 server:
CkMailMan_putPopUsername(mailman,"pop3_login2");
CkMailMan_putPopPassword(mailman,"pop3_password2");
CkMailMan_putMailPort(mailman,110);
CkMailMan_putPopSsl(mailman,FALSE);
success = CkMailMan_Pop3BeginSession(mailman);
if (success == FALSE) {
printf("%s\n",CkMailMan_lastErrorText(mailman));
CkMailMan_Dispose(mailman);
CkEmail_Dispose(email);
return;
}
// Review the LastErrorText to see that the connection was made via the SSH tunnel:
printf("%s\n",CkMailMan_lastErrorText(mailman));
success = CkMailMan_Pop3EndSession(mailman);
if (success == FALSE) {
printf("%s\n",CkMailMan_lastErrorText(mailman));
CkMailMan_Dispose(mailman);
CkEmail_Dispose(email);
return;
}
// Close the SSH tunnel.
success = CkMailMan_SshCloseTunnel(mailman);
if (success == FALSE) {
printf("%s\n",CkMailMan_lastErrorText(mailman));
CkMailMan_Dispose(mailman);
CkEmail_Dispose(email);
return;
}
CkMailMan_Dispose(mailman);
CkEmail_Dispose(email);
}