doveadm-pw(1) - Dovecot's password hash generator and validator

SYNOPSIS

doveadm [GLOBAL OPTIONS] pw -l

doveadm [GLOBAL OPTIONS] pw [-p password] [-r rounds] [-s scheme] [-u user] [-V]

doveadm [GLOBAL OPTIONS] pw -t hash [-p password] [-u user]

DESCRIPTION

doveadm pw is used to generate password hashes for different password scheme s 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.

If you want to use this feature to verify or generate passwords without configuring Dovecot first, you can use doveadm -O pw to do so.

OPTIONS

-l

List all supported password scheme s and exit successfully.

There are up to three optional password scheme\ s: 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 scheme s 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 CRYPT scheme will be used (with the $2y$ bcrypt format). It is also possible to append an encoding suffix to the scheme. Supported encoding suffixes are: .b64, .base64 and .hex.

See also password schemes 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 DIGEST-MD5.

-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

A DIGEST-MD5 hash for jane.roe@example.com.

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

A CRAM-MD5 hash for john.doe@example.com.

$ doveadm pw
Enter new password:
Retype new password:
{CRAM-MD5}913331d8782236a8ecba7764a63aa27b26437fd40ca878d887f11d81245c2c6b

SEE ALSO

doveadm(1)