dotfiles/zsh/.oh-my-zsh/plugins/genpass/genpass-apple

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2024-06-19 00:06:56 +02:00
#!/usr/bin/env zsh
#
# Usage: genpass-apple [NUM]
#
# Generate a password made of 6 pseudowords of 6 characters each
# with the security margin of at least 128 bits.
#
# Example password: xudmec-4ambyj-tavric-mumpub-mydVop-bypjyp
#
# If given a numerical argument, generate that many passwords.
emulate -L zsh -o no_unset -o warn_create_global -o warn_nested_var
if [[ ARGC -gt 1 || ${1-1} != ${~:-<1-$((16#7FFFFFFF))>} ]]; then
print -ru2 -- "usage: $0 [NUM]"
return 1
fi
zmodload zsh/system zsh/mathfunc || return
{
local -r vowels=aeiouy
local -r consonants=bcdfghjklmnpqrstvwxz
local -r digits=0123456789
# Sets REPLY to a uniformly distributed random number in [1, $1].
# Requires: $1 <= 256.
function -$0-rand() {
local c
while true; do
sysread -s1 c || return
# Avoid bias towards smaller numbers.
(( #c < 256 / $1 * $1 )) && break
done
typeset -g REPLY=$((#c % $1 + 1))
}
local REPLY chars
repeat ${1-1}; do
# Generate 6 pseudowords of the form cvccvc where c and v
# denote random consonants and vowels respectively.
local words=()
repeat 6; do
words+=('')
repeat 2; do
for chars in $consonants $vowels $consonants; do
-$0-rand $#chars || return
words[-1]+=$chars[REPLY]
done
done
done
local pwd=${(j:-:)words}
# Replace either the first or the last character in one of
# the words with a random digit.
-$0-rand $#digits || return
local digit=$digits[REPLY]
-$0-rand $((2 * $#words)) || return
pwd[REPLY/2*7+2*(REPLY%2)-1]=$digit
# Convert one lower-case character to upper case.
while true; do
-$0-rand $#pwd || return
[[ $vowels$consonants == *$pwd[REPLY]* ]] && break
done
# NOTE: We aren't using ${(U)c} here because its results are
# locale-dependent. For example, when upper-casing 'i' in Turkish
# locale we would get 'İ', a.k.a. latin capital letter i with dot
# above. We could set LC_CTYPE=C locally but then we would run afoul
# of this zsh bug: https://www.zsh.org/mla/workers/2020/msg00588.html.
local c=$pwd[REPLY]
printf -v c '%o' $((#c - 32))
printf "%s\\$c%s\\n" "$pwd[1,REPLY-1]" "$pwd[REPLY+1,-1]" || return
done
} always {
unfunction -m -- "-${(b)0}-*"
} </dev/urandom