Comment 4 for bug 1987683

:-)

"""
For the SHA-based methods the SALT string can be a simple string of
which up to 16 characters are used. The MD5-based implementation used
up to eight characters.. It was decided to allow one extension which
follows an invention Sun implemented in their pluggable crypt
implementation. If the SALT strings starts with

   rounds=<N>$

where N is an unsigned decimal number the numeric value of N is used
to modify the algorithm used. As will be explained later, the
SHA-based algorithm contains a loop which can be run an arbitrary
number of times. The more rounds are performed the higher the CPU
requirements are. This is a safety mechanism which might help
countering brute-force attacks in the face of increasing computing
power.

The default number of rounds for both algorithms is 5000.
"""