#!/usr/bin/env zsh
# zeasypki -- easy PKI
# Copyright (C) 2022 Sergey Matveev <stargrave@stargrave.org>

set -e

KEY_ENCRYPT_RECIPIENT=${KEY_ENCRYPT_RECIPIENT:-12AD32689C660D426967FD75CB8205632107AD8A}
COUNTRY=${COUNTRY:-RU}

# Turn on PyGOST utilities
path=(~/local/stow/py310/bin ~/work/pygost/pygost/asn1schemas $path)
export -TU PYTHONPATH pythonpath
pythonpath=(~/work/pygost ~/work/pyderasn)

key_encrypt() {
    gpg --encrypt --recipient $KEY_ENCRYPT_RECIPIENT
}

key_decrypt() {
    gpg --decrypt
}

# ------------------------ >8 ------------------------

usage() {
    >&2 <<EOF
Usage:
  \$ $ZSH_ARGZERO:t ca [ecdsa|gost] NAME -- new CA keypair
  \$ $ZSH_ARGZERO:t list-ca              -- list CA keypairs
  \$ $ZSH_ARGZERO:t list                 -- list EE ones
  \$ $ZSH_ARGZERO:t rem                  -- list certificate expirations
  \$ $ZSH_ARGZERO:t new KEY              -- new EE
  \$ $ZSH_ARGZERO:t renew KEY            -- renew EE
  \$ $ZSH_ARGZERO:t dane KEY             -- show DANE SHA256 hash
  \$ $ZSH_ARGZERO:t encrypt KEY          -- encrypt private key
  \$ $ZSH_ARGZERO:t keypair KEY          -- PEM-encoded full keypair
EOF
    exit 1
}

zmodload -F zsh/files b:zf_mkdir
zmodload zsh/mapfile

key_get() {
    [[ -s $1/key.pem ]] &&
        REPLY=`< ${1}/key.pem` ||
        REPLY=`key_decrypt < ${1}/key.pem.enc`
}

certtool_genkey() {
    certtool --generate-privkey --ecc --bits $1 --no-text
}

ca_new_ecdsa() {
    local domain=$1
    local key=`mktemp`
    local tmpl=`mktemp`
    local cert=`mktemp`
    trap "rm -f $key $tmpl $cert" HUP PIPE INT QUIT TERM EXIT
    > $tmpl <<EOF
dn = "cn=$domain,c=$COUNTRY"
serial = 1
expiration_days = 3650
ca
cert_signing_key
EOF
    certtool_genkey 512 > $key
    certtool \
        --generate-self-signed \
        --load-privkey $key \
        --template $tmpl \
        --outfile $cert
    reply=(${mapfile[$key]} ${mapfile[$cert]})
}

ee_key_new_ecdsa() {
    certtool_genkey 256
}

ee_key_new_gost() {
    cert-selfsigned-example.py --cn does-not-matter --ai 256A --only-key
}

ee_renew_ecdsa() {
    local ca=$1
    local domain=$2
    local cakey=`mktemp`
    local key=`mktemp`
    local tmpl=`mktemp`
    local cert=`mktemp`
    trap "rm -f $cakey $key $tmpl $cert" HUP PIPE INT QUIT TERM EXIT
    key_get ca/ecdsa/$ca
    mapfile[$cakey]=$REPLY
    key_get ee/ecdsa/$ca/$domain
    mapfile[$key]=$REPLY
    > $tmpl <<EOF
dn = "cn=$domain,c=RU"
expiration_days = 365
signing_key
dns_name = "$domain"
EOF
    certtool \
        --load-ca-certificate ca/ecdsa/$ca/cer.pem \
        --load-ca-privkey $cakey \
        --generate-certificate \
        --load-privkey $key \
        --template $tmpl
}

ee_renew_gost() {
    local ca=$1
    local domain=$2
    local cakey=`mktemp`
    local key=`mktemp`
    local cert=`mktemp`
    trap "rm -f $cakey $key $cert" HUP PIPE INT QUIT TERM EXIT
    key_get ca/gost/$ca
    mapfile[$cakey]=$REPLY
    >> $cakey < ca/gost/$ca/cer.pem
    key_get ee/gost/$ca/$domain
    mapfile[$key]=$REPLY
    cert-selfsigned-example.py \
        --issue-with $cakey \
        --reuse-key $key \
        --cn $domain --country $COUNTRY --ai 256A
}

ca_new_gost() {
    local domain=$1
    local key=`mktemp`
    local cert=`mktemp`
    trap "rm -f $key $cert" HUP PIPE INT QUIT TERM EXIT
    cert-selfsigned-example.py \
        --ca \
        --cn $domain \
        --country $COUNTRY \
        --serial 1 \
        --ai 512C \
        --out-key $key \
        --out-cert $cert
    reply=(${mapfile[$key]} ${mapfile[$cert]})
}

dane_ecdsa() {
    certtool --key-id --hash=sha256
}

dane_gost() {
    cert-dane-hash.py
}

case $1 in
(ca)
    [[ $# -eq 3 ]] || usage
    algo=$2
    domain=$3
    dst=ca/$algo/$domain
    zf_mkdir -p $dst
    [[ -s $dst/key.pem ]] && {
        print $dst/key.pem already exists >&2
        exit 1
    }
    ca_new_${algo} $domain
    _umask=`umask`
    umask 077
    mapfile[${dst}/key.pem]=${reply[1]}
    umask $_umask
    mapfile[${dst}/cer.pem]=${reply[2]}
    print $dst
    ;;
(encrypt)
    [[ $# -eq 2 ]] || usage
    key=$2/key.pem
    [[ -s $key ]] || {
        print no $key found >&2
        exit 1
    }
    umask 077
    key_encrypt < $key > $key.enc
    rm $key
    ;;
(new)
    [[ $# -eq 2 ]] || usage
    cols=(${(s:/:)2})
    algo=${cols[2]}
    ca=${cols[3]}
    domain=${cols[4]}
    dst=ee/$algo/$ca/$domain
    [[ $dst = $2 ]]
    zf_mkdir -p $dst
    [[ -s $dst/key.pem ]] && {
        print $dst/key.pem already exists >&2
        exit 1
    }
    _umask=`umask`
    umask 077
    ee_key_new_${algo} > $dst/key.pem
    umask $_umask
    ee_renew_${algo} $ca $domain > $dst/cer.pem
    ;;
(renew)
    [[ $# -eq 2 ]] || usage
    cols=(${(s:/:)2})
    algo=${cols[2]}
    ca=${cols[3]}
    domain=${cols[4]}
    ee_renew_${algo} $ca $domain > ee/$algo/$ca/$domain/cer.pem
    ;;
(dane)
    [[ $# -eq 2 ]] || usage
    dane_${${(s:/:)2}[2]} < $2/cer.pem
    ;;
(keypair)
    [[ $# -eq 2 ]] || usage
    key_get $2
    print -- "$REPLY"
    cat $2/cer.pem
    ;;
(rem)
    zmodload -F zsh/datetime b:strftime
    export LC_ALL=C
    for cer (**/cer.pem) {
        certtool --certificate-info < $cer | while read line ; do
            [[ $line =~ "^\s*Not After: .*" ]] && break
        done
        [[ $MATCH ]]
        # Not After: Sat Jul 02 10:02:29 UTC 2022
        cols=(${=MATCH})
        strftime -s ts_ugly -r "%b %d %H:%M:%S UTC %Y" ${(j: :)cols[4,-1]}
        strftime -s ts_good %F $ts_ugly
        print REM $ts_good +30 MSG $cer
    }
    ;;
(list) print -C1 ee/*/*/*(/on) ;;
(list-ca) print -C1 ca/*/*(/on) ;;
(*) usage ;;
esac