Lantronix EDS4100 Server User Manual


 
12: Security Settings
EDS User Guide 103
SSL Settings
Secure Sockets Layer (SSL) is a protocol for managing the security of data transmission over the
Internet. It provides encryption, authentication, and message integrity services. SSL is widely used
for secure communication to a web server.
Certificate/Private key combinations can be obtained from an external Certificate Authority (CA)
and downloaded into the unit. Self-signed certificates with associated private key can be
generated by the device server itself.
For more information regarding Certificates and how to obtain them, see SSL Certificates and
Private Keys (on page 104).
SSL uses digital certificates for authentication and cryptography against eavesdropping and
tampering. Sometimes only the server is authenticated, sometimes both server and client. The
EDS can be server and/or client, depending on the application. Public key encryption systems
exchange information and keys and set up the encrypted tunnel.
Efficient symmetric encryption methods encrypt the data going through the tunnel after it is
established. Hashing provides tamper detection.
Applications that can make use of SSL are Tunneling, Secure Web Server, and WLAN interface.
The EDS supports SSlv3 and its successors, TLS1.0 and TLS1.1.
Note: An incoming SSlv2 connection attempt is answered with an SSlv3 response. If the
initiator also supports SSLv3, SSLv3 handles the rest of the connection.
SSL Cipher Suites
The SSL standard defines only certain combinations of certificate type, key exchange method,
symmetric encryption, and hash method. Such a combination is called a cipher suite. Supported
cipher suites include the following:
Whichever side is acting as server decides which cipher suite to use for a connection. It is usually
the strongest common denominator of the cipher suite lists supported by both sides.
Table 12-13 Supported Cipher Suites
Certificate Key Exchange Encryption Hash
DSA DHE 3DES SHA1
RSA RSA 128 bits AES SHA1
RSA RSA Triple DES SHA1
RSA RSA 128 bits RC4 MD5
RSA RSA 128 bits RC4 SHA1
RSA 1024 bits RSA 56 bits RC4 MD5
RSA 1024 bits RSA 56 bits RC4 SHA1
RSA 1024 bits RSA 40 bits RC4 MD5