FTPS client for Linux/AIX

First of all, we have to differentiate between FTPS, SFTP and FTP over SSH.

FTPS is an extension of FTP that add supports for the TLS and SSL cryptographic protocols. 

It is available in two forms known as FTPS Implicit SSL where a required SSL session is established between client and server before any data is exchanged adn services run on port 990 and FTPS Explicit SSL where the ftp client needs to send an explicit command to ftp server to initiate a secure control connection. The default FTP server port is used.

SFTP is a sub-system of the SSH  protocol and typically runs on port 22.
It encrypts both commands and data, preventing passwords and sensitive information from being transmitted openly over the network

 FTP over SSH, the practice of tunneling FTP through an SSH connection.

Requirements:

• OpenSSL to be installed (at least version openssl-0.9.71-1.aix5.1.ppc.rpm)

• C compiler, for instance XL C/C++ for AIX

For AIX,

I chose curl client. You have to download the source and compile it.
If you want to configure the client with ssl support and it is not in the default path, use: 

./configure --with-ssl=/usr/include/openssl

make 

make install

If you are having some problems with your certificate and you want to disable this you can use the switch -k

This is the syntax to upload a file to the ftp server
curl -v -k --ftp-ssl -T file.txt ftp://username:password=@ftpserver/dir

If you want to download a file, use -O instead of -T. 

For Linux,

I chose lftp client. You have to compile the package with the openssl option or you won't be able to connect through an ftps server.

./configure --with-openssl=/usr/include/openssl

make 

make install

Once you have installed the client, you have to configure the file lftp.conf

To allow communication through ssl you have to add the option

set ftp:ssl-allow

To allow transfers in a script you have to add
set ftp:ssl-protect-data true

 Resources

http://www.hyperorg.com/blogger/2008/01/01/beginner-to-beginner-ftp-via-curl/


http://www-03.ibm.com/software/products/en/xlcpp-aix