apg-go is a simple APG-like password generator written in Go. It tries to replicate the functionality of the "Automated Password Generator", which hasn't been maintained since 2003. Since more and more Unix distributions are abondoning the tool, I was looking for an alternative. FreeBSD for example recommends "security/makepasswd", which is written in Perl but requires a lot of dependency packages and doesn't offer the feature-set/flexibility of APG.
Since FIPS-181 (pronouncable passwords) has been withdrawn in 2015, apg-go does not follow this standard. Instead it implements the Koremutake Syllables System in its pronouncable password mode.
There is a ready-to-use Docker image hosted on Github.
- Download the image:
$ docker pull ghcr.io/wneessen/apg-go:main
- Run the image:
$ docker run ghcr.io/wneessen/apg-go:main
apg-go can be found as /security/apg
in the FreeBSD ports
tree.
Find apg-go in Arch Linux AUR.
Alternatively use the PKGBUILD file
in this git repository
- Download release
$ curl -LO https://github.com/wneessen/apg-go/releases/download/v<version>/apg-v<version>-<os>-<architecture>.tar.gz $ curl -LO https://github.com/wneessen/apg-go/releases/download/v<version>/apg-v<version>-<os>-<architecture>.tar.gz.sha256
- Verify the checksum
Make sure the checksum of the downloaded file and the checksum in the .sha256 match
$ sha256 apg-v<version>-<os>-<architecture>.tar.gz $ cat apg-v<version>-<os>-<architecture>.tar.gz.sha256
- Extract archive
$ tar xzf apg-v<version>-<os>-<architecture>.tar.gz
- Execute
$ ./apg
- Download release
PS> Invoke-RestMethod -Uri https://github.com/wneessen/apg-go/releases/download/v<version>/apg-v<version>-windows-<architecture>.zip -OutFile apg-v<version>-windows-<architecure>.zip PS> Invoke-RestMethod -Uri https://github.com/wneessen/apg-go/releases/download/v<version>/apg-v<version>-windows-<architecture>.zip.sha256 -OutFile apg-v<version>-windows-<architecure>.zip.sha256
- Verify the checksum
Make sure the checksum of the downloaded file and the checksum in the .sha256 match
PS> Get-FileHash apg-v<version>-windows-<architecture>.zip | Format-List PS> type apg-v<version>-windows-<architecture>.zip.sha256
- Extract archive
PS> Expand-Archive -LiteralPath apg-v<version>-windows-<architecture>
- Execute
PS> cd apg-v<version>-windows-<architecture> PS> apg.exe
- Download sources
$ curl -LO https://github.com/wneessen/apg-go/archive/refs/tags/v<version>.tar.gz
- Extract source
$ tar xzf v<version>.tar.gz
- Build binary
$ cd apg-go-<version> $ go build -o apg ./...
- Execute the brand new binary
$ ./apg
It is recommed to install apg in a directory of your $PATH
environment. To do so run:
(In this example we use /usr/local/bin
as system-wide binary path. YMMV)
$ sudo cp apg /usr/local/bin/apg
Since v0.4.0 the CLI and the main package functionality have been separated from each other, which makes
it easier to use the apg-go
package in other Go code as well. This way you can make of the password
generation in your own code without having to rely on the actual apg-go binary.
Code examples on how to use the package can be found in the example-code directory.
By default apg-go will generate 6 passwords, with a minimum length of 12 characters and a maxiumum length of 20 characters. The generated password will use a character set constructed from lower case, upper case and numeric characters.
$ ./apg-go
R8rCC8bw5NvJmTUK2g
cHB9qogTbfdzFgnH
hoHfpWAHHSNa4Q
QyjscIsZkQGh
904YqsU5SnoqLo2w
utdFKXdeiXFzM
Let's assume you want to generate a single password, constructed out of upper case, numeric
and special characters. Since lower case is part of the default set, you would need to disable them
by setting the -L
parameter. In addition you would set the -S
parameter to enable special
characters. Finally the parameter -n 1
is needed to keep apg-go from generating more than one
password:
$ ./apg-go -n 1 -L -S
XY7>}H@5U40&_A1*9I$
Since the old style switches can be kind of confusing, it is recommended to use the "new style"
parameters instead. The new style is all combined in the -M
parameter. Using the upper case
version of a parameter argument enables a feature, while the lower case version disabled it. The
previous example could be represented like this in new style:
$ ./apg-go -n 1 -M lUSN
$</K?*|M)%8\U$5JA5~
Generated passwords can sometimes be a bit hard to read for humans, especially when ambiguous
characters are part of the password. Some characters in the ASCII character set look similar to
each other. In example it can be hard to differentiate an upper case I from a lower case l.
Same applies to the number zero (0) and the upper case O. To not run into issues with human
readability, you can set the -H
parameter to toggle on the "human readable" feature. When the
option is set, apg-go will avoid using any of the typical ambiguous characters in the generated
passwords.
$ ./apg-go -n 1 -M LUSN -H
YpranThY3b6b5%\6ARx
Let's assume, that for whatever reason, your generated password can never include a colon (:) sign. For
this specific case, you can use the -E
parameter to specify a list of characters that are to be excluded
from the password generation character set:
$ ./apg-go -n 1 -M lUSN -H -E :
~B2\%E_|\VV|/5C7EF=
If you want to generate complex passwords, there is a shortcut for this as well. By setting the -C
parameter, apg-go will automatically default to the most secure settings. The complex parameter
basically implies that the password will use all available characters (lower case, upper case,
numeric and special) and will make sure that human readability is disabled.
$ ./apg-go -n 1 -C
{q6cvz9le5_fo"X7
By default, apg-go will generate a password with a random length between 12 and 20 characters. If you
want to be more specific, you can use the -m
and -x
parameters to override the defaults. Let's
assume you want a single complex password with a length of exactly 32 characters, you can do so by
running:
$ ./apg-go -n 1 -C -m 32 -x 32
5lc&HBvx=!EUY*;'/t&>B|~sudhtyDBu
If you need to read out a password, it can be helpful to know the corresponding word for that character in
the phonetic alphabet. By setting the -l
parameter, agp-go will provide you with the phonetic spelling
(english language) of your newly created password:
$ ./apg-go -n 1 -M LUSN -H -E : -l
fUTDKeFsU+zn3r= (foxtrot/Uniform/Tango/Delta/Kilo/echo/Foxtrot/sierra/Uniform/PLUS_SIGN/zulu/november/THREE/romeo/EQUAL_SIGN)
Since v0.4.0 apg-go supports pronouncable passwords, anologous to the original c-apg using the -a 0
flag. The original c-apg implemented FIPS-181, which was withdrawn in 2015 for generating pronouncable
passwords. Since the standard is not recommended anymore, apg-go
instead make use of the
Koremutake Syllables System. Similar to the original apg, agp-go
will automatically randomly add special characters and number (from the human-readable pool) to each
generated pronouncable password. Additionally it will perform a "coinflip" for each Koremutake syllable
and decided if it should switch the case of one of the characters to an upper-case character.
Using the -t
parameter, apg-go
will display a spelled out version of the pronouncable password, where
each syllable or number/special character is seperated with a "-" (dash) and if the syllable is not a
Koremutake syllable the character will be spelled out the same was as with activated -l
in the
non-pronouncable password mode (-a 1
).
Note on password length: The -m
and -x
parameters will work in prouncable password mode, but
please keep in mind, that due to the nature how syllables work, your generated password might exceed
the desired length by one complete syllable (which can be up to 3 characters long).
Security consideration: Please keep in mind, that pronouncable passwords are less secure then truly randomly created passwords, due to the nature how syllables work. As a rule of thumb, it is recommended to multiply the length of your generated pronouncable passwords by at least 1.5 times, compared to truly randomly generated passwords. It might also be helpful to run the pronoucable password mode with enabled "HIBP" flag, so that each generated password is automatically checked against "Have I Been Pwned" database.
$ ./apg-go -a 0 -n 1
KebrutinernMy
$ ./apg-go -a 0 -n 1 -m 15 -x 15 -t
pEnbocydrageT*En (pEn-bo-cy-dra-geT-ASTERISK-En)
Even though, the passwords that apg-go generated for you, are secure, there is a minimal chance, that someone on the planet used exactly the same password before and that this person was part of an internet leak or hack, which exposed the password to the public. Such passwords are not considered secure anymore as they usually land on public available password lists, that are used by crackers.
To be on the safe side, you can use the -p
parameter, to enable a HIBP check. When the feature is
enabled, apg-go will check the HIBP database at https://haveibeenpwned.com if that password has been
leaked before and provide you with a warning if that is the case.
Please be aware, that this is a live check against the HIBP API, which not only requires internet
connectivity, but also might take between 500ms to 1s to complete. When you generating a bigger list
of password -n 100
, the process could take much longer than without the -p
feature enabled.
apg-go replicates most of the parameters of the original c-apg. Some parameters are different though:
-a <algorithm>
: Choose password generation algorithm (Default: 1)0
: Pronouncable password generation (Koremutake syllables)1
: Random password generation according to password modes/flags
-m <length>
: The minimum length of the password to be generated (Default: 12)-x <length>
: The maximum length of the password to be generated (Default: 20)-n <number of passwords>
: The amount of passwords to be generated (Default: 6)-E <list of characters>
: Do not use the specified characters in generated passwords-M <[LUNSHClunshc]>
: New style password parameters (upper-case enables, lower-case disables)-L
: Use lower-case characters in passwords (Default: on)-U
: Use upper-case characters in passwords (Default: on)-N
: Use numeric characters in passwords (Default: on)-S
: Use special characters in passwords (Default: off)-H
: Avoid ambiguous characters in passwords (i. e.: 1, l, I, o, O, 0) (Default: off)-C
: Generate complex passwords (implies -L -U -N -S and disables -H) (Default: off)-l
: Spell generated passwords in random password mode (Default: off)-t
: Spell generated passwords in pronouncable password mode (Default: off)-p
: Check the HIBP database if the generated passwords was found in a leak before (Default: off) // this feature requires internet connectivity-h
: Show a CLI help text-v
: Show the version number
Thanks to the following people for contributing to the apg-go codebase:
- Romain Tartière
- Abraham Ingersoll
- VinÃcius Zavam (Maintaining the FreeBSD port)