RSA*Encrypt() routines, require 3 bytes extra space for PKCS tags.
From Bugtraq posting <3845D352.95E47E26@core-sdi.com>, by
Gerardo Richarte <core.lists.bugtraq@CORE-SDI.COM>, dated
Wed, 1 Dec 1999 23:09:12 -0300
If you build packages with USE_RSAREF2 set, it is advisable to update
the rsaref package and any packages which may depend on it (openssl,
pgp2, ssh).