clarification: ;binary

[Christopher Oliva <Chris.Oliva@entrust.com>]

I often have to explain this issue to people so I thought I would raise it
once again on the list and hope that it will get clarified in the updated
version of RFC 2251.

There are four common interpretations for the use of ";binary":

1) It is used to override the BNF string syntax of values by encoding them
in BER
2) It is used to transport values where the only known/possible syntax is a
complex ASN.1 syntax (i.e. attributeCertificate)
3) It can optionally be used to transport values that have the "Binary"
syntax (the values must be BER encoded).
4) It is used to transport values that are non-printable (i.e. a string of
bytes that is not UTF8).

As far as I'm aware, the ldap RFCs do not state that ";binary" and a BER
encoding of values must be used for case number 4. In other words, there are
cases where an attribute syntax is a non-printable string of bytes and the
use of ";binary" is not required. One example of this is the Octet String
syntax.

For example, if I have an attribute named "private" with an Octet String
syntax, I can transmit this in ldap with the attribute description "private"
and encoded as 2 bytes "FFFF". It is not necessary to transmit this with the
attribute description "private;binary" and encoded as 4 bytes "0402FFFF".

Chris.