twofat

Manage TOTPs from CLI

• v2.1.1
• Repo: github.com/pepa65/twofat
• After: github.com/slandx/tfat
• Contact: github.com/pepa65
• Install: wget -qO- gobinaries.com/pepa65/twofat |sh
• Migration from pre v1.0.0 versions of twofat: Export the data with twofat v0 and import that with twofat v1.
• Migration from pre v2.0.0 versions of twofat: Export the data with twofat v1 (or v0) and import that with twofat v2.

Features

• Data saved with AES-GCM encrypt in ~/.twofat.enc (by default).
• Memory is wiped of SECRETs, garbage collected. Best not to give SECRET on the commandline! For even more security, run like: GODEBUG=clobberfree=1 twofat
• Datafile password can be changed.
• Display TOTPs of names matching regex, which auto-refresh.
• Add, rename, delete entry, reveal secret, copy TOTP to clipboard.
• Import & export entries from & to standardized OTPAUTH_URI file.
• Adjusts to terminal width for display. NAME truncated to 20 on display (shown in full on export and ls/list).
• Implementing RFC 4226/6238:
  • Defaults to HMAC-SHA-1 hashing, but allows HMAC-SHA-256 and HMAC-SHA-512.
  • Defaults to a TOTP length of 6, but allows 5 (for Steam), 7 (Twitch) and 8 (no other lengths seem to be in use).
  • The minimum SECRET length (128 bit, or 26 base32-chars) is not enforced (1 char is the minimum). Most OTP servers seem to use less than the minimum (security is not significantly reduced). There is no maximum length for a SECRET in twofat.
  • A 30 second timeout seems to be more or less universal, and twofat only supports 30 for period LENGTH. (Making this shorter does little to prevent the success of brute-force attacks.)

Build

# While in the repo root directory:
go build

# Or anywhere:
go get -u github.com/pepa65/twofat

# Smaller binary:
go build -ldflags="-s -w"

# More extreme shrinking:
upx twofat*

# Build for various architectures:
CGO_ENABLED=0 GOOS=linux GOARCH=amd64 go build -ldflags="-s -w" -o twofat
CGO_ENABLED=0 GOOS=linux GOARCH=arm go build -ldflags="-s -w" -o twofat_pi
CGO_ENABLED=0 GOOS=freebsd GOARCH=amd64 go build -ldflags="-s -w" -o twofat_bsd
CGO_ENABLED=0 GOOS=darwin GOARCH=amd64 go build -ldflags="-s -w" -o twofat_osx
CGO_ENABLED=0 GOOS=windows GOARCH=amd64 go build -ldflags="-s -w" -o twofat.exe

Usage

twofat v2.1.1 - Manage TOTPs from CLI
The CLI is interactive & colorful, output to Stderr. Password can be piped in.
When output is redirected, only pertinent plain text is sent to Stdout.
* Repo:       github.com/pepa65/twofat <pepa65@passchier.net>
* Datafile:   ~/.twofat.enc  (default, depends on the binary's name)
* Usage:      twofat  [COMMAND]  [ -d | --datafile  DATAFILE ]
  == COMMAND:
[ show | view ]  [REGEX [ -c | --case ]]
    Display all TOTPs with NAMEs [matching REGEX] (show/view is optional).
list | ls  [REGEX [ -c | --case ]]
    List all NAMEs [matching REGEX].
add | insert | entry  NAME  [TOTP-OPTIONS]  [ -f | --force ]  [SECRET]
    Add a new entry NAME with SECRET (queried when not given).
    If -f/--force: existing NAME overwritten, no NAME max.length check.
totp | temp  [TOTP-OPTIONS]  [SECRET]
    Show the TOTP for SECRET (queried when not given), no datafile access.
delete | remove | rm  NAME  [ -f | --force ]
    Delete entry NAME. If -f/--force: no confirmation asked.
rename | move | mv  NAME  NEWNAME  [ -f | --force ]
    Rename entry NAME to NEWNAME, if -f/--force: no max.length checks.
import  FILE  [ -f | --force ]
    Import lines with OTPAUTH_URI from file FILE.
    If -f/--force: existing NAME overwritten, no NAME max.length check.
export  [FILE]              Export OTPAUTH_URI-format entries [to file FILE].
reveal | secret  NAME       Show Secret of entry NAME.
clip | copy | cp  NAME      Put TOTP of entry NAME onto the clipboard.
password | passwd | pw      Change datafile encryption password.
version | --version | -V    Show version.
help | --help | -h          Show this help text.
  == REGEX:  Optional, case-insensitive matching (unless -c/--case is given).
  == TOTP-OPTIONS:
-s | --size  LENGTH       TOTP length: 5-8 (default: 6).
-a | --algorithm  HASH    Hash algorithm: SHA1/SHA256/SHA512 (default: SHA1).

Import/Export data

twofat abides by the backup standard from: https://www.ietf.org/archive/id/draft-linuxgemini-otpauth-uri-01.html

Each exported line has a otpauth URI of the form: otpauth://totp/NAME?secret=SECRET&algorithm=HASH&digits=LENGTH&period=PERIOD&issuer=NAME (the capitalized parts are variable parameters: NAME, SECRET, HASH, LENGTH, PERIOD).

• The NAME should not have a colon : or % (messes with URI conversion). (NAME could be ISSUER:ACCOUNTNAME, but twofat uses the full NAME for the issuer parameter.)
• The SECRET is the base32 RFC3548 seed (without the = padding!) for the OTPs.
• NAME and SECRET are mandatory.
• The HASH for algorithm is SHA1 (the default), SHA256 or SHA512.
• The LENGTH for digits is most often 6, but can be set to 5 (for Steam), 7 (Twitch) or 8 (Microsoft).
• The PERIOD for period is fixed to 30 (the default) in (almost?) all apps.
• On import, digits, period and algorithm will be set to the defaults when not specified.
• The issuer is set to NAME on export from twofat, and is ignored on import.