CRYPT_SUNMD5(7) Standards, Environments, and Macros CRYPT_SUNMD5(7)

NAME

crypt_sunmd5 - password hashing module using MD5 message hash
algorithm

SYNOPSIS

/usr/lib/security/$ISA/crypt_sunmd5.so

DESCRIPTION

The crypt_sunmd5 module is a one-way password hashing module for use
with crypt(3C) that uses the MD5 message hash algorithm. The
algorithm identifier for crypt.conf(5) and policy.conf(5) is md5.


This module is designed to make it difficult to crack passwords that
use brute force attacks based on high speed MD5 implementations that
use code inlining, unrolled loops, and table lookup.


The maximum password length for crypt_sunmd5 is 255 characters.


The following options can be passed to the module by means of
crypt.conf(5):

rounds=<positive_number>
Specifies the number of additional rounds
of MD5 to use in generation of the salt;
the default number of rounds is 4096.
Negative values have no effect and are
ignored, that is, the number of rounds
cannot be lowered below 4096.

The number of additional rounds is stored
in the salt string returned by
crypt_gensalt(3C). For example:

$md5,rounds=1000$nlxmTTpz$

When crypt_gensalt(3C) is being used to
generate a new salt, if the number of
additional rounds configured in
crypt.conf(5) is greater than that in the
old salt, the value from crypt.conf(5) is
used instead. This allows for migration
to stronger (but more time-consuming)
salts on password change.

ATTRIBUTES

See attributes(7) for descriptions of the following attributes:


+---------------+-----------------+
|ATTRIBUTE TYPE | ATTRIBUTE VALUE |
+---------------+-----------------+
|MT-Level | Safe |
+---------------+-----------------+

SEE ALSO

passwd(1), crypt(3C), crypt_genhash_impl(3C), crypt_gensalt(3C),
crypt_gensalt_impl(3C), getpassphrase(3C), crypt.conf(5), passwd(5),
policy.conf(5), attributes(7)

December 23, 2003 CRYPT_SUNMD5(7)