Ubuntu Manpage: doveadm-pw - Dovecot's password hash generator

Provided by: dovecot-core_2.2.22-1ubuntu2.14_amd64

NAME

       doveadm-pw - Dovecot's password hash generator

SYNOPSIS

       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]

DESCRIPTION

       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.

OPTIONS

Global doveadm(1) options:

-D 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.

-v Enables verbosity, including progress counter.

Command specific options:

-l 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 http://wiki2.dovecot.org/Authentication/PasswordSchemes 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: http://wiki2.dovecot.org/Authentication/Mechanisms/DigestMD5

-V 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.

EXAMPLE

       The  first  password  hash  is  a  DIGEST-MD5  hash  for jane.roe@example.com.  The second
       password hash is a CRAM-MD5 hash for john.doe@example.com.

       doveadm pw -s digest-md5 -u jane.roe@example.com
       Enter new password:
       Retype new password:
       {DIGEST-MD5}9b9dcb4466233a9307bbc33708dffda0
       doveadm pw
       Enter new password:
       Retype new password:
       {CRAM-MD5}913331d8782236a8ecba7764a63aa27b26437fd40ca878d887f11d81245c2c6b

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