Based on PR 33317 by Yoshito Komatsu.
SASL is a method for adding authentication support to connection-based
protocols. To use SASL, a protocol includes a command for identifying and
authenticating a user to a server and for optionally negotiating protection
of subsequent protocol interactions. If its use is negotiated, a security
layer is inserted between the protocol and the connection.
This is the Cyrus SASL plugin that implements the LDAPDB authentication
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