Has only one connection (no need for a DATA connection).Has a standards background which strictly defines most (if not all) aspects of operations.Doesn’t have a standard way to get and change file and directory attributes.Doesn’t define a standard for file name character sets (encodings).Requires a secondary DATA channel, which makes it hard to use behind the firewalls.Doesn’t have a uniform directory listing format.FTP and SSL/TLS support is built into many internet communication frameworks.SSL/TLS has good authentication mechanisms (X.509 certificate features).Provides services for server-to-server file transfer.Here’s the brief list of pros and cons of the two protocols: FTPS
SSH FILE TRANSFER PROTOCOL SOFTWARE
Some SSH software implementations use X.509 certificates for authentication, but in fact they don’t validate the whole certificate chain - only the public key is used (which makes such authentication incomplete and similar to SSH key authentication).
Neither does it contain information that lets one reliably validate integrity and authenticity. It doesn't contain any information about the owner of the key. An X.509 certificate has an associated private key, which is usually stored separately from the certificate for security reasons.Īn SSH key contains only a public key (the associated private key is stored separately).
SSH FILE TRANSFER PROTOCOL VERIFICATION
Verification can be done both by computer and to some extent by a human. This information lets the other side verify the integrity of the certificate itself and the authenticity of the certificate owner. X.509 certificates include the public key and certain information about the certificate owner. For authentication FTPS (or, to be more precise, the SSL/TLS protocol under FTP) uses X.509 certificates, while SFTP (the SSH protocol) uses SSH keys. In later versions, SFTP has been extended to provide not just file upload/download operations, but also some file-system operations, such as file lock, symbolic link creation, etc.īoth FTPS and SFTP use a combination of an asymmetric algorithm (RSA, DSA), symmetric algorithm (DES/3DES, AES, Twofish etc.) and key-exchange algorithm. All commands (requests) are packed to binary messages and sent to the server, which replies with binary reply packets. SFTP is a binary protocol, the latest version of which is standardized in RFC 4253. This is not FTP over SSL and not FTP over SSH (which is also technically possible, but very rare). In fact SFTP is an abbreviation of “SSH File Transfer Protocol”.
Another (similar) mistake is that SFTP is thought to be some kind of FTP over SSL. The SFTP abbreviation is often mistakenly used to specify some kind of Secure FTP, by which people most often mean FTPS.
Consequently, SCP is not used anymore and SFTP gains popularity day by day. Version 1 of the SSH protocol is outdated, insecure, and generally not recommended for use. Later, SSH was extended with the file transfer protocol - first SCP (in SSH 1.x), then SFTP (in SSH2). The primary function of SSH was to secure remote shell access to UNIX systems. In UNIX systems another security standard has grown, the SSH family of protocols. The secured version of FTP is called FTPS. Security in FTP is provided by employing the SSL/TLS protocol for channel encryption as defined in RFC 2228. The major drawbacks are the lack of a uniform format for directory listing (this problem has been partially solved by introducing the MLST command, but it’s not supported by some servers) and the presence of a secondary connection (the DATA connection). While FTP is very popular, it has certain disadvantages that make it harder to use. FTP provides functions to upload, download, and delete files, create and delete directories, and read directory contents. File transfer over the network using the FTP protocol (defined by RFC 959 and later additions) has its roots in the year 1980, when the first RFC for the FTP protocol was published.
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