This documentation is for Dovecot v2.x, see wiki1 for v1.x documentation.



doveadm-pw - Dovecot's password hash generator


doveadm [-Dv] pw -l
doveadm [-Dv] pw [-p password] [-r rounds] [-s scheme] [-u user] [-V]
doveadm [-Dv] pw -t hash [-p password] [-u user]


doveadm pw is used to generate password hashes for different password schemes and optionally verify the generated hash.

All generated password hashes have a {scheme} prefix, for example {SHA512-CRYPT.HEX}. All passdbs have a default scheme for passwords stored without the {scheme} prefix. The default scheme can be overridden by storing the password with the scheme prefix.


Global doveadm(1) options:

Enables verbosity and debug messages.
-o setting=value
Overrides the configuration setting from /etc/dovecot/dovecot.conf and from the userdb with the given value. In order to override multiple settings, the -o option may be specified multiple times.
Enables verbosity, including progress counter.

Command specific options:

List all supported password schemes and exit successfully.
There are up to three optional password schemes: BLF-CRYPT (Blowfish crypt), SHA256-CRYPT and SHA512-CRYPT. Their availability depends on the system's currently used libc.
-p password
The plain text password for which the hash should be generated. If no password was given doveadm(1) will prompt interactively for one.
-r rounds
The password schemes BLF-CRYPT, SHA256-CRYPT and SHA512-CRYPT supports a variable number of encryption rounds. The following table shows the minimum/maximum number of encryption rounds per scheme. When the -r option was omitted the default number of encryption rounds will be applied.
 Scheme       | Minimum | Maximum   | Default
 BLF-CRYPT    |       4 |        31 |       5
 SHA256-CRYPT |    1000 | 999999999 |    5000
 SHA512-CRYPT |    1000 | 999999999 |    5000
-s scheme
The password scheme which should be used to generate the hashed password. By default the CRAM-MD5 scheme will be used. It is also possible to append an encoding suffix to the scheme. Supported encoding suffixes are: .b64, .base64 and .hex.
See also for more details about password schemes.
-t hash
Test if the given password hash matches a given plain text password. You should enclose the password hash in single quotes, if it contains one or more dollar signs ($). The plain text password may be passed using the -p option. When no password was specified, doveadm(1) will prompt interactively for one.
-u user
When the DIGEST-MD5 scheme is used, also the user name must be given, because the user name is a part of the generated hash. For more information about Digest-MD5 please read also:
When this option is given, the hashed password will be internally verified. The result of the verification will be shown after the hashed password, enclosed in parenthesis.


The first password hash is a DIGEST-MD5 hash for The second password hash is a CRAM-MD5 hash for

doveadm pw -s digest-md5 -u
Enter new password:
Retype new password:
doveadm pw
Enter new password:
Retype new password:

See Also



Tools/Doveadm/Pw (last edited 2015-06-06 05:30:02 by PageImporter)