This option sets the ciphers on which SSL will decide during the negotiation phase of the SSL connection. Samba can use any of the following ciphers:
DEFAULT
DES-CFB-M1
NULL-MD5
RC4-MD5
EXP-RC4-MD5
RC2-CBC-MD5
EXP-RC2-CBC-MD5
IDEA-CBC-MD5
DES-CBC-MD5
DES-CBC-SHA
DES-CBC3-MD5
DES-CBC3-SHA
RC4-64-MD5
NULL
It is best not to set this option unless you are familiar with the SSL protocol and want to mandate a specific cipher suite.