DOVEADM-PW(1)                                Dovecot                                DOVEADM-PW(1)



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 option‐
       ally 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.

       -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 cur‐
              rently 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 encod‐
              ing 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.  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 AT example.com.  The second pass‐
       word hash is a CRAM-MD5 hash for john.doe AT example.com.

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

REPORTING BUGS
       Report bugs, including doveconf -n output, to  the  Dovecot  Mailing  List  <dovecot@dove‐
       cot.org>.   Information  about  reporting  bugs is available at: http://dovecot.org/bugre‐
       port.html

SEE ALSO
       doveadm(1)



Dovecot v2.2                                2013-08-17                              DOVEADM-PW(1)