#!/bin/bash
set -o pipefail
exec 5>&1

# Thanks to https://github.com/cvmiller -> https://github.com/cvmiller/expand6
source /srv/expand6.sh

log_f() {
  if [[ ${2} == "no_nl" ]]; then
    echo -n "$(date) - ${1}"
  elif [[ ${2} == "no_date" ]]; then
    echo "${1}"
  elif [[ ${2} != "redis_only" ]]; then
    echo "$(date) - ${1}"
  fi
  redis-cli -h redis LPUSH ACME_LOG "{\"time\":\"$(date +%s)\",\"message\":\"$(printf '%s' "${1}" | \
    tr '%&;$"_[]{}-\r\n' ' ')\"}" > /dev/null
  redis-cli -h redis LTRIM ACME_LOG 0 ${LOG_LINES} > /dev/null
}

if [[ "${SKIP_LETS_ENCRYPT}" =~ ^([yY][eE][sS]|[yY])+$ ]]; then
  log_f "SKIP_LETS_ENCRYPT=y, skipping Let's Encrypt..."
  sleep 365d
  exec $(readlink -f "$0")
fi

log_f "Waiting for Docker API..." no_nl
until ping dockerapi -c1 > /dev/null; do
  sleep 1
done
log_f "OK" no_date

ACME_BASE=/var/lib/acme
SSL_EXAMPLE=/var/lib/ssl-example

mkdir -p ${ACME_BASE}/acme/private

restart_containers(){
  for container in $*; do
    log_f "Restarting ${container}..." no_nl
    C_REST_OUT=$(curl -X POST http://dockerapi:8080/containers/${container}/restart | jq -r '.msg')
    log_f "${C_REST_OUT}" no_date
  done
}

array_diff() {
  # https://stackoverflow.com/questions/2312762, Alex Offshore
  eval local ARR1=\(\"\${$2[@]}\"\)
  eval local ARR2=\(\"\${$3[@]}\"\)
  local IFS=$'\n'
  mapfile -t $1 < <(comm -23 <(echo "${ARR1[*]}" | sort) <(echo "${ARR2[*]}" | sort))
}

verify_hash_match(){
  CERT_HASH=$(openssl x509 -noout -modulus -in "${1}" | openssl md5)
  KEY_HASH=$(openssl rsa -noout -modulus -in "${2}" | openssl md5)
  if [[ ${CERT_HASH} != ${KEY_HASH} ]]; then
    log_f "Certificate and key hashes do not match!"
    return 1
  else
    log_f "Verified hashes."
    return 0
  fi
}

get_ipv4(){
  local IPV4=
  local IPV4_SRCS=
  local TRY=
  IPV4_SRCS[0]="api.ipify.org"
  IPV4_SRCS[1]="ifconfig.co"-
  IPV4_SRCS[2]="icanhazip.com"
  IPV4_SRCS[3]="v4.ident.me"
  IPV4_SRCS[4]="ipecho.net/plain"
  IPV4_SRCS[5]="ip4.mailcow.email"
  until [[ ! -z ${IPV4} ]] || [[ ${TRY} -ge 10 ]]; do
    IPV4=$(curl --connect-timeout 3 -m 10 -L4s ${IPV4_SRCS[$RANDOM % ${#IPV4_SRCS[@]} ]} | grep -E "^((25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.){3}(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)$")
    [[ ! -z ${TRY} ]] && sleep 1
    TRY=$((TRY+1))
  done
  echo ${IPV4}
}

get_ipv6(){
  local IPV6=
  local IPV6_SRCS=
  local TRY=
  IPV6_SRCS[0]="ifconfig.co"
  IPV6_SRCS[1]="icanhazip.com"
  IPV6_SRCS[2]="v6.ident.me"
  IPV6_SRCS[3]="ip6.mailcow.email"
  until [[ ! -z ${IPV6} ]] || [[ ${TRY} -ge 10 ]]; do
    IPV6=$(curl --connect-timeout 3 -m 10 -L6s ${IPV6_SRCS[$RANDOM % ${#IPV6_SRCS[@]} ]} | grep "^\([0-9a-fA-F]\{0,4\}:\)\{1,7\}[0-9a-fA-F]\{0,4\}$")
    [[ ! -z ${TRY} ]] && sleep 1
    TRY=$((TRY+1))
  done
  echo ${IPV6}
}

[[ ! -f ${ACME_BASE}/dhparams.pem ]] && cp ${SSL_EXAMPLE}/dhparams.pem ${ACME_BASE}/dhparams.pem

if [[ -f ${ACME_BASE}/cert.pem ]] && [[ -f ${ACME_BASE}/key.pem ]]; then
  ISSUER=$(openssl x509 -in ${ACME_BASE}/cert.pem -noout -issuer)
  if [[ ${ISSUER} != *"Let's Encrypt"* && ${ISSUER} != *"mailcow"* ]]; then
    log_f "Found certificate with issuer other than mailcow snake-oil CA and Let's Encrypt, skipping ACME client..."
    sleep 3650d
    exec $(readlink -f "$0")
  else
    declare -a SAN_ARRAY_NOW
    SAN_NAMES=$(openssl x509 -noout -text -in ${ACME_BASE}/cert.pem | awk '/X509v3 Subject Alternative Name/ {getline;gsub(/ /, "", $0); print}' | tr -d "DNS:")
    if [[ ! -z ${SAN_NAMES} ]]; then
      IFS=',' read -a SAN_ARRAY_NOW <<< ${SAN_NAMES}
      log_f "Found Let's Encrypt or mailcow snake-oil CA issued certificate with SANs: ${SAN_ARRAY_NOW[*]}"
    fi
  fi
else
  if [[ -f ${ACME_BASE}/acme/fullchain.pem ]] && [[ -f ${ACME_BASE}/acme/private/privkey.pem ]]; then
    if verify_hash_match ${ACME_BASE}/acme/fullchain.pem ${ACME_BASE}/acme/private/privkey.pem; then
      log_f "Restoring previous acme certificate and restarting script..."
      cp ${ACME_BASE}/acme/fullchain.pem ${ACME_BASE}/cert.pem
      cp ${ACME_BASE}/acme/private/privkey.pem ${ACME_BASE}/key.pem
      # Restarting with env var set to trigger a restart,
      exec env TRIGGER_RESTART=1 $(readlink -f "$0")
    fi
  ISSUER="mailcow"
  else
    log_f "Restoring mailcow snake-oil certificates and restarting script..."
    cp ${SSL_EXAMPLE}/cert.pem ${ACME_BASE}/cert.pem
    cp ${SSL_EXAMPLE}/key.pem ${ACME_BASE}/key.pem
    exec env TRIGGER_RESTART=1 $(readlink -f "$0")
  fi
fi

log_f "Waiting for database... "
while ! mysqladmin ping --host mysql -u${DBUSER} -p${DBPASS} --silent; do
  sleep 2
done
log_f "Initializing, please wait... "


while true; do
  if [[ "${SKIP_IP_CHECK}" =~ ^([yY][eE][sS]|[yY])+$ ]]; then
    SKIP_IP_CHECK=y
  fi
  unset SQL_DOMAIN_ARR
  unset VALIDATED_CONFIG_DOMAINS
  unset ADDITIONAL_VALIDATED_SAN
  declare -a SQL_DOMAIN_ARR
  declare -a VALIDATED_CONFIG_DOMAINS
  declare -a ADDITIONAL_VALIDATED_SAN
  IFS=',' read -r -a ADDITIONAL_SAN_ARR <<< "${ADDITIONAL_SAN}"
  log_f "Detecting IP addresses... " no_nl
  IPV4=$(get_ipv4)
  IPV6=$(get_ipv6)
  log_f "OK" no_date

  # Container ids may have changed
  CONTAINERS_RESTART=($(curl --silent http://dockerapi:8080/containers/json | jq -r '.[] | {name: .Config.Labels["com.docker.compose.service"], id: .Id}' | jq -rc 'select( .name | tostring | contains("nginx-mailcow") or contains("postfix-mailcow") or contains("dovecot-mailcow")) | .id' | tr "\n" " "))

  log_f "Waiting for domain table... " no_nl
  while [[ -z ${DOMAIN_TABLE} ]]; do
    curl --silent http://nginx/ >/dev/null 2>&1
    DOMAIN_TABLE=$(mysql -h mysql-mailcow -u ${DBUSER} -p${DBPASS} ${DBNAME} -e "SHOW TABLES LIKE 'domain'" -Bs)
    [[ -z ${DOMAIN_TABLE} ]] && sleep 10
  done
  log_f "OK" no_date

  while read domains; do
    SQL_DOMAIN_ARR+=("${domains}")
  done < <(mysql -h mysql-mailcow -u ${DBUSER} -p${DBPASS} ${DBNAME} -e "SELECT domain FROM domain WHERE backupmx=0 UNION SELECT alias_domain FROM alias_domain" -Bs)

  for SQL_DOMAIN in "${SQL_DOMAIN_ARR[@]}"; do
    A_CONFIG=$(dig A autoconfig.${SQL_DOMAIN} +short | tail -n 1)
    AAAA_CONFIG=$(dig AAAA autoconfig.${SQL_DOMAIN} +short | tail -n 1)
    if [[ ! -z ${AAAA_CONFIG} ]]; then
      log_f "Found AAAA record for autoconfig.${SQL_DOMAIN}: ${AAAA_CONFIG} - skipping A record check"
      if [[ $(expand ${IPV6:-"0000:0000:0000:0000:0000:0000:0000:0000"}) == $(expand ${AAAA_CONFIG}) ]] || [[ ${SKIP_IP_CHECK} == "y" ]]; then
        log_f "Confirmed AAAA record autoconfig.${SQL_DOMAIN}"
        VALIDATED_CONFIG_DOMAINS+=("autoconfig.${SQL_DOMAIN}")
      else
        log_f "Cannot match your IP ${IPV6:-NO_IPV6_LINK} against hostname autoconfig.${SQL_DOMAIN} ($(expand ${AAAA_CONFIG}))"
      fi
    elif [[ ! -z ${A_CONFIG} ]]; then
      log_f "Found A record for autoconfig.${SQL_DOMAIN}: ${A_CONFIG}"
      if [[ ${IPV4:-ERR} == ${A_CONFIG} ]] || [[ ${SKIP_IP_CHECK} == "y" ]]; then
        log_f "Confirmed A record autoconfig.${SQL_DOMAIN}"
        VALIDATED_CONFIG_DOMAINS+=("autoconfig.${SQL_DOMAIN}")
      else
        log_f "Cannot match your IP ${IPV4} against hostname autoconfig.${SQL_DOMAIN} (${A_CONFIG})"
      fi
    else
      log_f "No A or AAAA record found for hostname autoconfig.${SQL_DOMAIN}"
    fi

    A_DISCOVER=$(dig A autodiscover.${SQL_DOMAIN} +short | tail -n 1)
    AAAA_DISCOVER=$(dig AAAA autodiscover.${SQL_DOMAIN} +short | tail -n 1)
    if [[ ! -z ${AAAA_DISCOVER} ]]; then
      log_f "Found AAAA record for autodiscover.${SQL_DOMAIN}: ${AAAA_DISCOVER} - skipping A record check"
      if [[ $(expand ${IPV6:-"0000:0000:0000:0000:0000:0000:0000:0000"}) == $(expand ${AAAA_DISCOVER}) ]] || [[ ${SKIP_IP_CHECK} == "y" ]]; then
        log_f "Confirmed AAAA record autodiscover.${SQL_DOMAIN}"
        VALIDATED_CONFIG_DOMAINS+=("autodiscover.${SQL_DOMAIN}")
      else
        log_f "Cannot match your IP ${IPV6:-NO_IPV6_LINK} against hostname autodiscover.${SQL_DOMAIN} ($(expand ${AAAA_DISCOVER}))"
      fi
    elif [[ ! -z ${A_DISCOVER} ]]; then
      log_f "Found A record for autodiscover.${SQL_DOMAIN}: ${A_DISCOVER}"
      if [[ ${IPV4:-ERR} == ${A_DISCOVER} ]] || [[ ${SKIP_IP_CHECK} == "y" ]]; then
        log_f "Confirmed A record autodiscover.${SQL_DOMAIN}"
        VALIDATED_CONFIG_DOMAINS+=("autodiscover.${SQL_DOMAIN}")
      else
        log_f "Cannot match your IP ${IPV4} against hostname autodiscover.${SQL_DOMAIN} (${A_DISCOVER})"
      fi
    else
      log_f "No A or AAAA record found for hostname autodiscover.${SQL_DOMAIN}"
    fi
  done

  A_MAILCOW_HOSTNAME=$(dig A ${MAILCOW_HOSTNAME} +short | tail -n 1)
  AAAA_MAILCOW_HOSTNAME=$(dig AAAA ${MAILCOW_HOSTNAME} +short | tail -n 1)
  if [[ ! -z ${AAAA_MAILCOW_HOSTNAME} ]]; then
    log_f "Found AAAA record for ${MAILCOW_HOSTNAME}: ${AAAA_MAILCOW_HOSTNAME} - skipping A record check"
    if [[ $(expand ${IPV6:-"0000:0000:0000:0000:0000:0000:0000:0000"}) == $(expand ${AAAA_MAILCOW_HOSTNAME}) ]] || [[ ${SKIP_IP_CHECK} == "y" ]]; then
      log_f "Confirmed AAAA record ${MAILCOW_HOSTNAME}"
      VALIDATED_MAILCOW_HOSTNAME=${MAILCOW_HOSTNAME}
    else
      log_f "Cannot match your IP ${IPV6:-NO_IPV6_LINK} against hostname ${MAILCOW_HOSTNAME} ($(expand ${AAAA_MAILCOW_HOSTNAME}))"
    fi
  elif [[ ! -z ${A_MAILCOW_HOSTNAME} ]]; then
    log_f "Found A record for ${MAILCOW_HOSTNAME}: ${A_MAILCOW_HOSTNAME}"
    if [[ ${IPV4:-ERR} == ${A_MAILCOW_HOSTNAME} ]] || [[ ${SKIP_IP_CHECK} == "y" ]]; then
      log_f "Confirmed A record ${A_MAILCOW_HOSTNAME}"
      VALIDATED_MAILCOW_HOSTNAME=${MAILCOW_HOSTNAME}
    else
      log_f "Cannot match your IP ${IPV4} against hostname ${MAILCOW_HOSTNAME} (${A_MAILCOW_HOSTNAME})"
    fi
  else
    log_f "No A or AAAA record found for hostname ${MAILCOW_HOSTNAME}"
  fi

  for SAN in "${ADDITIONAL_SAN_ARR[@]}"; do
    if [[ ${SAN} == ${MAILCOW_HOSTNAME} ]]; then
      continue
    fi
    A_SAN=$(dig A ${SAN} +short | tail -n 1)
    if [[ ! -z ${A_SAN} ]]; then
      log_f "Found A record for ${SAN}: ${A_SAN}"
      if [[ ${IPV4:-ERR} == ${A_SAN} ]] || [[ ${SKIP_IP_CHECK} == "y" ]]; then
        log_f "Confirmed A record ${SAN}"
        ADDITIONAL_VALIDATED_SAN+=("${SAN}")
      else
        log_f "Cannot match your IP against hostname ${SAN}"
      fi
    else
      log_f "No A record for ${SAN} found"
    fi
  done

  # Unique elements
  ALL_VALIDATED=(${VALIDATED_MAILCOW_HOSTNAME} $(echo ${VALIDATED_CONFIG_DOMAINS[*]} ${ADDITIONAL_VALIDATED_SAN[*]} | xargs -n1 | sort -u | xargs))
  if [[ -z ${ALL_VALIDATED[*]} ]]; then
    log_f "Cannot validate hostnames, skipping Let's Encrypt for 1 hour."
    log_f "Use SKIP_LETS_ENCRYPT=y in mailcow.conf to skip it permanently."
    sleep 1h
    exec $(readlink -f "$0")
  fi

  array_diff ORPHANED_SAN SAN_ARRAY_NOW ALL_VALIDATED
  if [[ ! -z ${ORPHANED_SAN[*]} ]] && [[ ${ISSUER} != *"mailcow"* ]]; then
    DATE=$(date +%Y-%m-%d_%H_%M_%S)
    log_f "Found orphaned SAN ${ORPHANED_SAN[*]} in certificate, moving old files to ${ACME_BASE}/acme/private/${DATE}.bak/, keeping key file..."
    mkdir -p ${ACME_BASE}/acme/private/${DATE}.bak/
    [[ -f ${ACME_BASE}/acme/private/account.key ]] && mv ${ACME_BASE}/acme/private/account.key ${ACME_BASE}/acme/private/${DATE}.bak/
    [[ -f ${ACME_BASE}/acme/fullchain.pem ]] && mv ${ACME_BASE}/acme/fullchain.pem ${ACME_BASE}/acme/private/${DATE}.bak/
    [[ -f ${ACME_BASE}/acme/cert.pem ]] && mv ${ACME_BASE}/acme/cert.pem ${ACME_BASE}/acme/private/${DATE}.bak/
    cp ${ACME_BASE}/acme/private/privkey.pem ${ACME_BASE}/acme/private/${DATE}.bak/ # Keep key for TLSA 3 1 1 records
  fi

  ACME_RESPONSE=$(acme-client \
    -v -e -b -N -n \
    -a 'https://letsencrypt.org/documents/LE-SA-v1.2-November-15-2017.pdf' \
    -f ${ACME_BASE}/acme/private/account.key \
    -k ${ACME_BASE}/acme/private/privkey.pem \
    -c ${ACME_BASE}/acme \
    ${ALL_VALIDATED[*]} 2>&1 | tee /dev/fd/5)

  case "$?" in
    0) # new certs
      log_f "${ACME_RESPONSE}" redis_only
      # cp the new certificates and keys
      cp ${ACME_BASE}/acme/fullchain.pem ${ACME_BASE}/cert.pem
      cp ${ACME_BASE}/acme/private/privkey.pem ${ACME_BASE}/key.pem

      # restart docker containers
      if ! verify_hash_match ${ACME_BASE}/cert.pem ${ACME_BASE}/key.pem; then
        log_f "Certificate was successfully requested, but key and certificate have non-matching hashes, restoring mailcow snake-oil and restarting containers..."
        cp ${SSL_EXAMPLE}/cert.pem ${ACME_BASE}/cert.pem
        cp ${SSL_EXAMPLE}/key.pem ${ACME_BASE}/key.pem
      fi
      restart_containers ${CONTAINERS_RESTART[*]}
      ;;
    1) # failure
      log_f "${ACME_RESPONSE}" redis_only
      if [[ $ACME_RESPONSE =~ "No registration exists" ]]; then
        log_f "Registration keys are invalid, deleting old keys and restarting..."
        rm ${ACME_BASE}/acme/private/account.key
        exec $(readlink -f "$0")
      fi
      if [[ -f ${ACME_BASE}/acme/private/${DATE}.bak/fullchain.pem ]] && [[ -f ${ACME_BASE}/acme/private/${DATE}.bak/privkey.pem ]]; then
        log_f "Error requesting certificate, restoring previous certificate from backup and restarting containers...."
        cp ${ACME_BASE}/acme/private/${DATE}.bak/fullchain.pem ${ACME_BASE}/cert.pem
        cp ${ACME_BASE}/acme/private/${DATE}.bak/privkey.pem ${ACME_BASE}/key.pem
        TRIGGER_RESTART=1
      elif [[ -f ${ACME_BASE}/acme/fullchain.pem ]] && [[ -f ${ACME_BASE}/acme/private/privkey.pem ]]; then
        log_f "Error requesting certificate, restoring from previous acme request and restarting containers..."
        cp ${ACME_BASE}/acme/fullchain.pem ${ACME_BASE}/cert.pem
        cp ${ACME_BASE}/acme/private/privkey.pem ${ACME_BASE}/key.pem
        TRIGGER_RESTART=1
      fi
      if ! verify_hash_match ${ACME_BASE}/cert.pem ${ACME_BASE}/key.pem; then
        log_f "Error verifying certificates, restoring mailcow snake-oil and restarting containers..."
        cp ${SSL_EXAMPLE}/cert.pem ${ACME_BASE}/cert.pem
        cp ${SSL_EXAMPLE}/key.pem ${ACME_BASE}/key.pem
        TRIGGER_RESTART=1
      fi
      [[ ${TRIGGER_RESTART} == 1 ]] && restart_containers ${CONTAINERS_RESTART[*]}
      log_f "Retrying in 30 minutes..."
      sleep 30m
      exec $(readlink -f "$0")
      ;;
    2) # no change
      log_f "${ACME_RESPONSE}" redis_only
      if ! diff ${ACME_BASE}/acme/fullchain.pem ${ACME_BASE}/cert.pem; then
        log_f "Certificate was not changed, but active certificate does not match the verified certificate, fixing and restarting containers..."
        cp ${ACME_BASE}/acme/fullchain.pem ${ACME_BASE}/cert.pem
        cp ${ACME_BASE}/acme/private/privkey.pem ${ACME_BASE}/key.pem
        TRIGGER_RESTART=1
      fi
      if ! verify_hash_match ${ACME_BASE}/cert.pem ${ACME_BASE}/key.pem; then
        log_f "Certificate was not changed, but hashes do not match, restoring from previous acme request and restarting containers..."
        cp ${ACME_BASE}/acme/fullchain.pem ${ACME_BASE}/cert.pem
        cp ${ACME_BASE}/acme/private/privkey.pem ${ACME_BASE}/key.pem
        TRIGGER_RESTART=1
      fi
      log_f "Certificate was not changed"
      [[ ${TRIGGER_RESTART} == 1 ]] && restart_containers ${CONTAINERS_RESTART[*]}
      ;;
    *) # unspecified
      log_f "${ACME_RESPONSE}" redis_only
      if [[ -f ${ACME_BASE}/acme/private/${DATE}.bak/fullchain.pem ]] && [[ -f ${ACME_BASE}/acme/private/${DATE}.bak/privkey.pem ]]; then
        log_f "Error requesting certificate, restoring previous certificate from backup and restarting containers...."
        cp ${ACME_BASE}/acme/private/${DATE}.bak/fullchain.pem ${ACME_BASE}/cert.pem
        cp ${ACME_BASE}/acme/private/${DATE}.bak/privkey.pem ${ACME_BASE}/key.pem
        TRIGGER_RESTART=1
            elif [[ -f ${ACME_BASE}/acme/fullchain.pem ]] && [[ -f ${ACME_BASE}/acme/private/privkey.pem ]]; then
        log_f "Error requesting certificate, restoring from previous acme request and restarting containers..."
        cp ${ACME_BASE}/acme/fullchain.pem ${ACME_BASE}/cert.pem
        cp ${ACME_BASE}/acme/private/privkey.pem ${ACME_BASE}/key.pem
        TRIGGER_RESTART=1
      fi
      if ! verify_hash_match ${ACME_BASE}/cert.pem ${ACME_BASE}/key.pem; then
        log_f "Error verifying certificates, restoring mailcow snake-oil..."
        cp ${SSL_EXAMPLE}/cert.pem ${ACME_BASE}/cert.pem
        cp ${SSL_EXAMPLE}/key.pem ${ACME_BASE}/key.pem
        TRIGGER_RESTART=1
      fi
      [[ ${TRIGGER_RESTART} == 1 ]] && restart_containers ${CONTAINERS_RESTART[*]}
      log_f "Retrying in 30 minutes..."
      sleep 30m
      exec $(readlink -f "$0")
      ;;
  esac

  log_f "ACME certificate validation done. Sleeping for another day."
  sleep 1d

done