Password Generator

genpass.sh

#!/usr/bin/env bash
# ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
# PW Material Generator
# Notes:
#   - Used by genpass
#   - Generates 20 characters per invocation
#   - Takes ~1ms per character generated on an average
#     system
#   - Will _always_ lead with an ALPHA character
#   - Will _always_ include _at least one SPECIAL character
#     when the -s argument is supplied
# Arguments:
#   - -s           Include special characters
# Outputs:
#   - Randomly generated password 20 characters in length
# TODO:
#   - Allow SPEC input to facilitate various tool compliance
#     Previously looped pwgen until a compliant string was
#     produced.
# ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
__genpass_fount() {
  [[ "$2" == "-s" ]] && loggerx ERROR "Length must be specified after any arguments." && return 1
  if [[ "$1" == "-s" ]]; then
    local SPEC='!@#$%^&*()<>[]{}|_+-='
    local SPEC_SAFE="${SPEC:$(( RANDOM % ${#SPEC} )):1}"
    local ALPH_NUM=$(openssl rand -base64 128 | tr -dc 'a-zA-Z0-9' | tr -d '\n' | head -c 128)
    local ALPH_LEAD=$(openssl rand -base64 128 | tr -dc 'a-zA-Z' | tr -d '\n' | head -c 1)
    local RANDUP=$(echo -n "${SPEC}${ALPH_NUM}" | fold -w 1 | shuf | tr -d "\n" | head -c 18 | head -n 1)
    local OUTPUT_TAIL=$(echo -n "${RANDUP}${SPEC_SAFE}" | fold -w 1 | shuf | tr -d "\n")
    echo "${ALPH_LEAD}${OUTPUT_TAIL}"
  else
    openssl rand -base64 128 | tr -dc 'a-zA-Z0-9' | head -c 20 | head -n 1
    echo ''
  fi
}

# ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
# PW Generator
# Notes:
#   - Same as __genpass_fount
#   - No length limitation
#   - Defaults to 20 characters
# Arguments:
#   -s           Include special characters
#   <len> int    Length of the output string
# Outputs:
#   - Randomly generated password of any length.
# ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
genpass() {
  [[ "$2" == "-s" ]] && loggerx ERROR "Length must be specified after any arguments." && return 1
  local LEN="20"
  local FOUNT_LEN='20'
  if [[ "$1" == "-s" ]]; then
    { [[ -n $2 ]] && [[ $2 -ne $FOUNT_LEN ]] ; } && local LEN="$2"
    local GEN_RUNS=$(( (LEN / FOUNT_LEN) + 1 ))
    for ((GEN=0; GEN <= GEN_RUNS; GEN++)); do
      __genpass_fount -s | tr -d '\n'
    done | head -c "$LEN"
    echo ''
  else
    { [[ -n $1 ]] && [[ $1 -ne $FOUNT_LEN ]] ;} && local LEN="$1"
    local GEN_RUNS=$(( (LEN / FOUNT_LEN) + 1 ))
    for ((GEN=0; GEN <= GEN_RUNS; GEN++)); do
      __genpass_fount | tr -d '\n'
    done | head -c "$LEN"
    echo ''
  fi
}