man slappasswd (Administration système) - OpenLDAP password utility


slappasswd - OpenLDAP password utility


/usr/sbin/slappasswd [-v] [-u] [-s secret|-T file] [-h hash] [-c salt-format]


Slappasswd is used to generate an userPassword value suitable for use with ldapmodify(1) or slapd.conf(5) rootpw configuration directive.


enable verbose mode.
Generate RFC 2307 userPassword values (the default). Future versions of this program may generate alternative syntaxes by default. This option is provided for forward compatibility.
-s secret
The secret to hash. If this and -T are absent, the user will be prompted for the secret to hash. -s and -T and mutually exclusive flags.
-T file
Hash the contents of the file. If this and -s are absent, the user will be prompted for the secret to hash. -s and -T and mutually exclusive flags.
-h scheme
If -h is specified, one of the following RFC 2307 schemes may be specified: {CRYPT}, {MD5}, {SMD5}, {SSHA}, and {SHA}. The default is {SSHA}.

Note that scheme names may need to be protected, due to { and }, from expansion by the user's command interpreter.

{SHA} and {SSHA} use the SHA-1 algorithm (FIPS 160-1), the latter with a seed.

{MD5} and {SMD5} use the MD5 algorithm (RFC 1321), the latter with a seed.

{CRYPT} uses the crypt(3).

{CLEARTEXT} indicates that the new password should be added to userPassword as clear text.

-c crypt-salt-format
Specify the format of the salt passed to crypt(3) when generating {CRYPT} passwords. This string needs to be in sprintf(3) format and may include one (and only one) %s conversion. This conversion will be substituted with a string random characters from [A-Za-z0-9./]. For example, '%.2s' provides a two character salt and '$1$%.8s' tells some versions of crypt(3) to use an MD5 algorithm and provides 8 random characters of salt. The default is '%s', which provides 31 characters of salt.


The practice storing hashed passwords in userPassword violates Standard Track (RFC 2256) schema specifications and may hinder interoperability. A new attribute type, authPassword, to hold hashed passwords has been defined (RFC 3112), but is not yet implemented in slapd(8).

It should also be noted that the behavior of
crypt(3) is platform specific.


Use of hashed passwords does not protect passwords during protocol transfer. TLS or other eavesdropping protections should be in-place before using LDAP simple bind.

The hashed password values should be protected as if they
were clear text passwords.


ldappasswd(1), ldapmodify(1), slapd(8) slapd.conf(5) RFC 2307 RFC 2256 RFC 3112

"OpenLDAP Administrator's Guide" (


OpenLDAP is developed and maintained by The OpenLDAP Project ( OpenLDAP is derived from University of Michigan LDAP 3.3 Release.