X-Git-Url: https://zdv2.bktei.com/gitweb/BK-2020-03.git/blobdiff_plain/9c8765b4d681d1e705d7cec2d64bbf61ea98efff..a8f8046e9eff5728dedb61129f258e4cad7b4f61:/unitproc/bknpass?ds=inline diff --git a/unitproc/bknpass b/unitproc/bknpass index 4f53da0..f4930a0 100755 --- a/unitproc/bknpass +++ b/unitproc/bknpass @@ -1,14 +1,13 @@ #!/bin/bash - -# Date: 2020-01-20T16:34Z -# -# Author: Steven Baltakatei Sandoval (baltakatei.com) -# -# License: This bash script, `bknpass`, is licensed under GPLv3 or -# later by Steven Baltakatei Sandoval: -# +# Desc: Generate passphrase with specified number of bits of entropy +# Usage: bknpass [integer] +# Example: bknpass 256 +# Result: 9tnzcl0m4dsm22a95525zj93jj +# Version: 0.2.1 +# Depends: bash 5.1.8, GNU coreutils 8.32, bc 1.07.1, awk 5.1.0 +# License: # `bknpass`, an alphanumeric password generator -# Copyright (C) 2020 Steven Baltakatei Sandoval (baltakatei.com) +# Copyright (C) 2022 Steven Baltakatei Sandoval (baltakatei.com) # # This program is free software: you can redistribute it and/or modify # it under the terms of the GNU General Public License as published by @@ -22,94 +21,77 @@ # # A copy of the GNU General Public License may be found at # . -# -# Description: This bash script generates alphanumeric passphrases -# with a char-count determined by a user-provided number of bits of -# entropy. The passphrase is then outputted to stdout with a trailing -# newline. It works as follows: -# -# - Prompt user for an integer. This integer is the number of bits -# of entropy that the generated password should have. -# -# - Check if user-provided string is an integer using `bash` regular -# expression test. -# -# - Calculate the minimum number of alphanumeric characters required -# to encode the specified number of bits of entropy. -# -# - This step uses `bc` to calculate a logarithm float string -# and `awk` to convert the float into an integer, rounding up. -# -# - Use `tr`, `/dev/urandom`, and `head` to generate a random -# alphanumeric string with the length calculated in the previous -# step. -# -# - Use `echo` to display the passphrase in stdout with a trailing -# newline. -# -# Dependencies: bash, echo, bc, awk, tr, head. See end of file -# -# Tested on: -# -# - GNU/Linux Debian 10 +yell() { echo "$0: $*" >&2; } # print script path and all args to stderr +die() { yell "$*"; exit 111; } # same as yell() but non-zero exit status +try() { "$@" || die "cannot $*"; } # runs args as command, reports args if command fails +showUsage() { + # Desc: Display script usage information + # Usage: showUsage + # Version 0.0.1 + # Input: none + # Output: stdout + # Depends: GNU-coreutils 8.30 (cat) + cat <<'EOF' + USAGE: + bknpass [int entropy_bit_count] -#==Initialization== + EXAMPLE: + bknpass 128 +EOF +}; # Display information on how to use this script. +main() { + # Desc: main program + # Usage: main "$@" + # Input: $1: integer bits of entropy + # Output: stdout: string passphrase + # Depends: bash 5.1.8, GNU coreutils 8.32, bc 1.07.1, awk 5.1.0 + # Ref/Attrib: [1] "Check existence of input argument in a Bash shell script". https://stackoverflow.com/a/6482403 + # [2] "How do I test if a variable is a number in Bash?". https://stackoverflow.com/a/806923 + # [3] "Round a Number in a Bash Script". https://bits.mdminhazulhaque.io/linux/round-number-in-bash-script.html + # [4] "Logarithms in GNU bc". https://web.archive.org/web/20210211050732/http://phodd.net/gnu-bc/bcfaq.html#bclog + # [5] "BIP 173". Note: bech32 charset. https://github.com/bitcoin/bips/blob/master/bip-0173.mediawiki + # [6] "Bash Function to generate random password". https://www.thegeekstuff.com/2010/04/unix-bash-function-examples/ + charset="qpzry9x8gf2tvdw0s3jn54khce6mua7l"; # bech32. See [5]. + charset="$(tr -s "$charset" < <(echo -n "$charset"))"; # remove repeat chars + alphabet_size="$(echo -n "$charset" | wc -c)"; # number of unique chars + log_base=2; # entropy unit base (i.e. 2 for "bits of entropy") -let ALPHABET_SIZE="26+26+10" # number of unique chars in [:alnum:], argument fed to `tr -c` in 'Generate passphrase' step) -LOG_BASE=2 # Set logarithm base to 2 + # Check inputs + if [[ $# -gt 1 ]]; then showUsage; die "ERROR:Too many arguments:$#"; fi; -# Define `echoerr` function which outputs text to stderr - # Note: function copied from https://stackoverflow.com/a/2990533 -function echoerr { - echo "$@" 1>&2; -} + # Check for bc + if ! command -v bc 1>/dev/null 2>&1; then die "ERROR:bc not available"; fi; -# Define `rpass` function which generates an alphanumeric passphrase of length $1 (ex: `rpass 22` generates a 22-char string) - # Note: function adapted from https://www.thegeekstuff.com/2010/04/unix-bash-function-examples/ -function rpass { - cat /dev/urandom | LC_ALL=C tr -cd "[:alnum:]" | head -c ${1:-22} -} + ## Get entropy_bit_count + if [[ -z "$1" ]]; then + ### prompt user + showUsage; + echo -n "Please specify the required strength of the password in bits of entropy (ex: 256):" 1>&2; # prompt via stderr + read -r entropy_bit_count + else + entropy_bit_count="$1"; + fi; # See [1]. + ## Check entropy_bit_count + pattern="^[0-9]+$"; + if ! [[ $entropy_bit_count =~ $pattern ]] ; then die "ERROR:Not an integer:$entropy_bit_count"; fi; # See [2] -#==Main Program== + ## Calculate minimum count of chars needed for passphrase as float using 'bc' + ### Solve ln(a^n)/ln(2)=b for n where: + ### a=$alphabet_size + ### n=$char_count_float + ### b=$entropy_bit_count + char_count_float="$(echo "$entropy_bit_count*l($log_base)/l($alphabet_size)" | bc -l)"; # See [4] -# Define $ENTROPY_BIT_COUNT1 as argument $1 or prompt user if $1 is not defined. - # note: argument test adapted from https://stackoverflow.com/a/6482403 -if [ -z "$1" ] -then - echo "Entropy bit count argument (\$1) not supplied." - # Get from user the number of bits of entropy. - echoerr -n "Please specify the required strength of the password in bits of entropy (ex: 256):" # prompt via stderr - read ENTROPY_BIT_COUNT1 -else - ENTROPY_BIT_COUNT1="$1" -fi + ## Round $char_count_float to next highest integer + char_count="$(echo "$char_count_float" | awk '{print ($0-int($0)>0)?int($0)+1:int($0)}')"; # See [3] -# Check if $ENTROPY_BIT_COUNT1 is an non-negative integer - # Note: Regular expression test is adapted from https://stackoverflow.com/a/806923 -RETEST1='^[0-9]+$' -if ! [[ $ENTROPY_BIT_COUNT1 =~ $RETEST1 ]] ; then - echo "error: Not an integer." >&2; exit 1 -fi - -# Calculate minimum count of chars needed to encode $ENTROPY_BIT_COUNT1 with alphabet size of $ALPHABET_SIZE as float - # Solve ln(a^n)/ln(2)=b for n using `bc` where - # a=$ALPHABET_SIZE - # n=$CHAR_COUNT1_FLOAT - # b=$ENTROPY_BIT_COUNT1 - # Note: `bc` logarithm usage adapted from http://phodd.net/gnu-bc/bcfaq.html#bashlog -CHAR_COUNT1_FLOAT=$(echo "$ENTROPY_BIT_COUNT1*l($LOG_BASE)/l($ALPHABET_SIZE)" | bc -l) - # Note: Float will be of form "21.49744370650136860806". This particular float should be rounded to "22" later. - -# Round $CHAR_COUNT1_FLOAT1 up to next highest integer for use as argument in later bash functions. - # Note: awk expression from https://bits.mdminhazulhaque.io/linux/round-number-in-bash-script.html -CHAR_COUNT1=$(echo "$CHAR_COUNT1_FLOAT" | awk '{print ($0-int($0)>0)?int($0)+1:int($0)}') - -# Generate passphrase -PASS1=$(rpass "$CHAR_COUNT1") -echo -e "$PASS1" + ## Generate and output passphrase + echo "$(LC_ALL=C tr -cd "$charset" < /dev/urandom | head -c "$char_count")"; # See [6] +}; # main program +( main "$@" ); # run 'main()' in subshell for 'die()' portability of script as sourced bash function. #==References== # @@ -148,53 +130,60 @@ echo -e "$PASS1" # Date: 2010-04-21 # Date Accessed: 2020-01-20 # -# - Dependencies: bash, echo, bc, awk, tr, head. +# - Bech32 base32 charset +# https://github.com/bitcoin/bips/blob/master/bip-0173.mediawiki +# Author: Pieter Wuille +# Date: 2017-03-20 +# License: BSD-2-Clause +# Date: Accessed: 2021-01-23 +# +# - Dependencies: bash, bc, echo, awk, tr, head # -# - GNU bash, version 5.0.3(1)-release (x86_64-pc-linux-gnu) -# Copyright (C) 2019 Free Software Foundation, Inc. +# - GNU bash, version 5.1.8(1)-release (x86_64-pc-linux-gnu) +# Copyright (C) 2020 Free Software Foundation, Inc. # License GPLv3+: GNU GPL version 3 or later # This is free software; you are free to change and redistribute it. # There is NO WARRANTY, to the extent permitted by law. -# -# - echo (GNU coreutils) 8.30 -# Copyright (C) 2018 Free Software Foundation, Inc. +# +# - bc 1.07.1 +# Copyright 1991-1994, 1997, 1998, 2000, 2004, 2006, 2008, 2012-2017 Free Software Foundation, Inc. +# +# - echo (GNU coreutils) 8.32 +# Copyright (C) 2020 Free Software Foundation, Inc. # License GPLv3+: GNU GPL version 3 or later . # This is free software: you are free to change and redistribute it. # There is NO WARRANTY, to the extent permitted by law. # # Written by Brian Fox and Chet Ramey. -# -# - bc 1.07.1 -# Copyright 1991-1994, 1997, 1998, 2000, 2004, 2006, 2008, 2012-2017 Free Software Foundation, Inc. -# -# - GNU Awk 4.2.1, API: 2.0 (GNU MPFR 4.0.2, GNU MP 6.1.2) -# Copyright (C) 1989, 1991-2018 Free Software Foundation. -# +# +# - GNU Awk 5.1.0, API: 3.0 (GNU MPFR 4.1.0, GNU MP 6.2.1) +# Copyright (C) 1989, 1991-2020 Free Software Foundation. +# # This program is free software; you can redistribute it and/or modify # it under the terms of the GNU General Public License as published by # the Free Software Foundation; either version 3 of the License, or # (at your option) any later version. -# +# # This program is distributed in the hope that it will be useful, # but WITHOUT ANY WARRANTY; without even the implied warranty of # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the # GNU General Public License for more details. -# +# # You should have received a copy of the GNU General Public License # along with this program. If not, see http://www.gnu.org/licenses/. # -# - tr (GNU coreutils) 8.30 -# Copyright (C) 2018 Free Software Foundation, Inc. +# - tr (GNU coreutils) 8.32 +# Copyright (C) 2020 Free Software Foundation, Inc. # License GPLv3+: GNU GPL version 3 or later . # This is free software: you are free to change and redistribute it. # There is NO WARRANTY, to the extent permitted by law. -# +# # Written by Jim Meyering. -# -# - head (GNU coreutils) 8.30 -# Copyright (C) 2018 Free Software Foundation, Inc. +# +# - head (GNU coreutils) 8.32 +# Copyright (C) 2020 Free Software Foundation, Inc. # License GPLv3+: GNU GPL version 3 or later . # This is free software: you are free to change and redistribute it. # There is NO WARRANTY, to the extent permitted by law. -# +# # Written by David MacKenzie and Jim Meyering.