Upgrading from v1 to v2

This document covers issues with upgrading from SASLv1 to SASLv2. To upgrade:

  • Install Cyrus SASL v2 as normal according to the installation guide. This will overwrite some manpages, but will not affect your current applications. Do NOT attempt to make it use the same directories, otherwise old Cyrus SASLv1 applications will no longer function.

  • Install your new Cyrus SASL v2 applications. Applications that use Cyrus SASLv1 will not use the Cyrus SASL v2 infrastructure (and vice-versa).

  • If you used /etc/sasldb for authentication, you’ll need to take the following steps to convert to using /etc/sasldb2 with Cyrus SASL v2:

    1. run utils/dbconverter-2 after installation.
    2. change the pwcheck_method in any config files to auxprop
    3. (optional) add auxprop_plugin to the config files, set to sasldb

  • If you used passwd, shadow, pam, kerberos_v4 or sia as your pwcheck_method in libsasl v1, you’ll need to convert to using saslauthd. Arrange to start saslauthd -a <method> on boot. Change pwcheck_method in any configuration files to saslauthd.

  • If you used pwcheck with libsasl v1, you can either continue to use pwcheck with libsasl v1 or you can switch to saslauthd, which offers more flexibility and a potentially much more efficient implementation.

  • If you are continuing to use some libsasl v1 applications, read onwards to understand the ramifications.

  • If you want to learn how to port applications from libsasl v1 to libsasl v2, you should read the converting applications guide.

Backwards Compatibility

Cyrus SASLv2 is incompatible with applications that use Cyrus SASLv1. This means that applications are unable to simultaneously link both versions of the library, and developers are encouraged to instead develop or upgrade their applications to link against the new libsasl.

Likewise, the format for the sasldb database has been completely revamped. See here for a discussion of the relevant upgrade issues related to sasldb. All new passwords stored in the sasldb database will be in plaintext, meaning that a compromised sasldb will compromise all services with the same passwords. (This situation isn’t significantly worse, cryptographically speaking, than the old method and allows the database to be easy to transition to another format, when the need arises.) Mechanisms requiring a more secure password database backend (e.g. SRP) should implement their own or use alternate property names within sasldb.

Coexistence with SASLv1

The two library versions and the associated utilities should be able to coexist on the same system. The man pages will be unable to coexist (but luckily the new manpages are much better!). The libsasl v2-specific utilities have had a “2” appended to their name for this purpose (e.g. saslpasswd2, sasldblistusers2). The new-style sasldb now defaults to the name /etc/sasldb2, but this is configurable.

Database Upgrades

While there does not seem to be any conflict with the keys stored in the database, it is not recommended for both versions of the library to use the same database file. Included in the utils directory is a program called dbconverter-2 which will allow you to convert from the old-format database to the new format. Note that if you continue to run older applications that rely on Cyrus SASLv1, the databases for SASLv1 and SASLv2 will not automatically be kept in sync.

Errors on migration

When migrating the /etc/sasldb database using the utils/dbconverter-2 utility, you may encounter the error message “Error opening password file”. This is usually due to the fact your SASL V1 library was compiled using a different version of Berkeley DB than the SASL V2 library. You can work around this by using Berkeley DB’s db_upgrade utility (possibly chaining the DB3 and DB4 upgrade utilities) to upgrade a copy of sasldb prior to conversion using dbconverter-2.

Here is the script we use at our installation, where SASL has to coexist with SASL2:

!/bin/sh
cp /etc/sasldb /tmp/sasldb.$$
/usr/local/BerkeleyDB.4/bin/db_upgrade /etc/sasldb
echo ""|/usr/local/sasl/sbin/dbconverter-2
cp /tmp/sasldb.$$ /etc/sasldb