WU-FTPD 2.6.1 release notes (July 2010)

produce the ciphertext output that must be decrypted by the recipient. Commonly
used private key algorithms include DES, Blowfish, AES, and IDEA.
• Public key algorithms. These algorithms use two mathematically related keys to
separate the process of encryption and decryption. By using functions that are
easy to perform in one direction but difficult to perform in the opposite direction,
the two keys provide a high level of security if large numbers are used. Commonly
used public key algorithms include RSA, El Gamal, and Diffie-Hellman.
While establishing a TLS session, you can use public key cryptography to exchange
a session key that is used in a private key algorithm. You can also use these public
keys to authenticate the server and, if required, the client, and to provide
session-level encryption and confidentiality for the entire session.
• Hash algorithms. These algorithms are a set of one-way functions that accept a
variable length input, and, after mathematical processing, produce a fixed length
output. The transformations of the data produce a fingerprint of the input. The
minor changes to the input appear as large changes in the output. Popular hash
algorithms include SHA-1, MD5, and RIPEMD.
Hash algorithms are used for integrity checking; that is, to ensure that data is not
tampered during transmission.
Prerequisites for Configuring the TLS/SSL Feature
Following are the prerequisites for configuring the TLS/SSL feature:
• The OpenSSL software
OpenSSL is an open source product that offers a general purpose cryptography
library and implementation of the Secure Sockets Layer (SSL v2/v3) and Transport
Layer Security (TLS v1) protocols. OpenSSL is tested and supported on different
HP-UX operating systems. OpenSSL A.00.09.07m is the latest version of OpenSSL
available on the HP-UX 11i v2 operating system. It is available to download at:
http://www.software.hp.com
The release notes for OpenSSL A.00.09.07m is available at:
www.hp.com/go/hpux-security-docs. On this page, select HP-UX OpenSSL
Software.
• The WU-FTPD 2.6.1 TLS enhancement bundle
The FTP-TLS enhancement bundle, ftp-ssl-ncf, contains TLS enhancement
libraries for the FTP client and server. The ftp(1) client and the ftpd(1M) server use
these enhancement libraries with OpenSSL to perform security operations.
12 WU-FTPD 2.6.1 Release Notes