acme.sh/dnsapi/dns_freedns.sh

#!/usr/bin/env sh

#This file name is "dns_freedns.sh"
#So, here must be a method dns_freedns_add()
#Which will be called by acme.sh to add the txt record to your api system.
#returns 0 means success, otherwise error.
#
#Author: David Kerr
#Report Bugs here: https://github.com/dkerr64/acme.sh
#
########  Public functions #####################

# Export FreeDNS userid and password in folowing variables...
#  FREEDNS_User=username
#  FREEDNS_Password=password
# login cookie is saved in acme account config file so userid / pw
# need to be set only when changed.

#Usage: dns_freedns_add   _acme-challenge.www.domain.com   "XKrxpRBosdIKFzxW_CT3KLZNf6q0HG9i01zxXp5CPBs"
dns_freedns_add() {
  fulldomain="$1"
  txtvalue="$2"

  _info "Add TXT record using FreeDNS"
  _debug "fulldomain: $fulldomain"
  _debug "txtvalue: $txtvalue"

  if [ -z "$FREEDNS_User" ] || [ -z "$FREEDNS_Password" ]; then
    if [ -z "$FREEDNS_COOKIE" ]; then
      _err "You did not specify the FreeDNS username and password yet."
      _err "Please export as FREEDNS_User / FREEDNS_Password and try again."
      return 1
    fi
    using_cached_cookies="true"
  else
    FREEDNS_COOKIE="$(_freedns_login "$FREEDNS_User" "$FREEDNS_Password")"
    if [ -z "$FREEDNS_COOKIE" ]; then
      return 1
    fi
    using_cached_cookies="false"
  fi

  _debug "FreeDNS login cookies: $FREEDNS_COOKIE (cached = $using_cached_cookies)"

  _saveaccountconf FREEDNS_COOKIE "$FREEDNS_COOKIE"

  htmlpage="$(_freedns_retrieve_subdomain_page "$FREEDNS_COOKIE")"
  if [ "$?" != "0" ]; then
    if [ "$using_cached_cookies" = "true" ]; then
      _err "Has your FreeDNS username and password channged?  If so..."
      _err "Please export as FREEDNS_User / FREEDNS_Password and try again."
    fi
    return 1
  fi

  # split our full domain name into two parts...
  top_domain="$(echo "$fulldomain" | rev | cut -d. -f -2 | rev)"
  sub_domain="$(echo "$fulldomain" | rev | cut -d. -f 3- | rev)"

  # Now convert the tables in the HTML to CSV.  This litte gem from
  # http://stackoverflow.com/questions/1403087/how-can-i-convert-an-html-table-to-csv    
  subdomain_csv="$(echo "$htmlpage" \
    | grep -i -e '</\?TABLE\|</\?TD\|</\?TR\|</\?TH' \
    | sed 's/^[\ \t]*//g' \
    | tr -d '\n' \
    | sed 's/<\/TR[^>]*>/\n/Ig' \
    | sed 's/<\/\?\(TABLE\|TR\)[^>]*>//Ig' \
    | sed 's/^<T[DH][^>]*>\|<\/\?T[DH][^>]*>$//Ig' \
    | sed 's/<\/T[DH][^>]*><T[DH][^>]*>/,/Ig' \
    | grep 'edit.php?' \
    | grep "$top_domain")"
  # The above beauty ends with striping out rows that do not have an
  # href to edit.php and do not have the top domain we are looking for.
  # So all we should be left with is CSV of table of subdomains we are
  # interested in.

  # Now we have to read through this table and extract the data we need
  lines=$(echo "$subdomain_csv" | wc -l)
  nl='
'
  i=0
  found=0
  while [ $i -lt $lines ]; do
    i=$(_math  $i + 1 )
    line="$(echo "$subdomain_csv" | cut -d "$nl" -f $i)"
    tmp="$(echo "$line" | cut -d ',' -f 1)"
    if [ $found = 0 ] && _startswith "$tmp" "<td>$top_domain"; then
      # this line will contain DNSdomainid for the top_domain
      tmp="$(echo "$line" | cut -d ',' -f 2)"
      url=${tmp#*=}
      url=${url%%>*}
      DNSdomainid=${url#*domain_id=}
      found=1
    else
      # lines contain DNS records for all subdomains
      dns_href="$(echo "$line" | cut -d ',' -f 2)"
      tmp=${dns_href#*>}
      DNSname=${tmp%%<*}
      DNStype="$(echo "$line" | cut -d ',' -f 3)"
      if [ "$DNSname" = "$fulldomain" ] && [ "$DNStype" = "TXT" ]; then
        tmp=${dns_href#*=}
        url=${tmp%%>*}
        DNSdataid=${url#*data_id=}
        # Now get current value for the TXT record.  This method may
        # produce inaccurate results as the value field is truncated
        # on this webpage. To get full value we would need to load
        # another page.  However we don't really need this so long as
        # there is only one TXT record for the acme chalenge subdomain.
        tmp="$(echo "$line" | cut -d ',' -f 4)"
        # strip the html double-quotes off the value
        tmp=${tmp#&quot;}
        DNSvalue=${tmp%&quot;}
        if [ $found != 0 ]; then
          break
          # we are breaking out of the loop at the first match of DNS name
          # and DNS type (if we are past finding the domainid). This assumes
          # that there is only ever one TXT record for the LetsEncrypt/acme
          # challenge subdomain.  This seems to be a reasonable assumption
          # as the acme client deletes the TXT record on successful validation.
        fi
      else
        DNSname=""
        DNStype=""
      fi
    fi
  done

  _debug "DNSname: $DNSname DNStype: $DNStype DNSdomainid: $DNSdomainid DNSdataid: $DNSdataid"
  _debug "DNSvalue: $DNSvalue"

  if [ -z "$DNSdomainid" ]; then
    # If domain ID is empty then something went wrong (top level
    # domain not found at FreeDNS). Cannot proceed.
    _debug "$htmlpage"
    _debug "$subdomain_csv"
    _err "Domain $top_domain not found at FreeDNS"
    return 1
  fi

  if [ -z "$DNSdataid" ]; then
    # If data ID is empty then specific subdomain does not exist yet, need
    # to create it this should always be the case as the acme client
    # deletes the entry after domain is validated.
    _freedns_add_txt_record "$FREEDNS_COOKIE" "$DNSdomainid" "$sub_domain" "$txtvalue"
    return $?
  else
    if [ "$txtvalue" = "$DNSvalue" ]; then
      # if value in TXT record matches value requested then DNS record
      # does not need to be updated. But...
      # Testing value match fails.  Website is truncating the value field.
      # So for now we will always go down the else path.  Though in theory
      # should never come here anyway as the acme client deletes
      # the TXT record on successful validation, so we should not even
      # have found a TXT record !!
      _info "No update necessary for $fulldomain at FreeDNS"
      return 0
    else
      # Delete the old TXT record (with the wrong value)
      _freedns_delete_txt_record "$FREEDNS_COOKIE" "$DNSdataid"
      if [ "$?" = "0" ]; then
        # And add in new TXT record with the value provided
        _freedns_add_txt_record "$FREEDNS_COOKIE" "$DNSdomainid" "$sub_domain" "$txtvalue"
      fi
      return $?
    fi
  fi
  return 0
}

#Usage: fulldomain txtvalue
#Remove the txt record after validation.
dns_freedns_rm() {
  fulldomain="$1"
  txtvalue="$2"

  _info "Delete TXT record using FreeDNS"
  _debug "fulldomain: $fulldomain"
  _debug "txtvalue: $txtvalue"

  # Need to read cookie from conf file again in case new value set
  # during login to FreeDNS when TXT record was created.

  #TODO acme.sh does not have a _readaccountconf() fuction
  FREEDNS_COOKIE="$(_read_conf "$ACCOUNT_CONF_PATH" "FREEDNS_COOKIE")"
  _debug "FreeDNS login cookies: $FREEDNS_COOKIE"

  htmlpage="$(_freedns_retrieve_subdomain_page "$FREEDNS_COOKIE")"
  if [ "$?" != "0" ]; then
    return 1
  fi

  # Now convert the tables in the HTML to CSV.  This litte gem from
  # http://stackoverflow.com/questions/1403087/how-can-i-convert-an-html-table-to-csv
  subdomain_csv="$(echo "$htmlpage" \
    | grep -i -e '</\?TABLE\|</\?TD\|</\?TR\|</\?TH' \
    | sed 's/^[\ \t]*//g' \
    | tr -d '\n' \
    | sed 's/<\/TR[^>]*>/\n/Ig' \
    | sed 's/<\/\?\(TABLE\|TR\)[^>]*>//Ig' \
    | sed 's/^<T[DH][^>]*>\|<\/\?T[DH][^>]*>$//Ig' \
    | sed 's/<\/T[DH][^>]*><T[DH][^>]*>/,/Ig' \
    | grep 'edit.php?' \
    | grep "$fulldomain")"
  # The above beauty ends with striping out rows that do not have an
  # href to edit.php and do not have the domain name we are looking for.
  # So all we should be left with is CSV of table of subdomains we are
  # interested in.

  # Now we have to read through this table and extract the data we need
  lines=$(echo "$subdomain_csv" | wc -l)
  nl='
'
  i=0
  found=0
  while [ $i -lt $lines ]; do
    i=$(_math  $i + 1 )
    line="$(echo "$subdomain_csv" | cut -d "$nl" -f $i)"
    dns_href="$(echo "$line" | cut -d ',' -f 2)"
    tmp=${dns_href#*>}
    DNSname=${tmp%%<*}
    DNStype="$(echo "$line" | cut -d ',' -f 3)"
    if [ "$DNSname" = "$fulldomain" ] && [ "$DNStype" = "TXT" ]; then
      tmp=${dns_href#*=}
      url=${tmp%%>*}
      DNSdataid=${url#*data_id=}
      tmp="$(echo "$line" | cut -d ',' -f 4)"
      # strip the html double-quotes off the value
      tmp=${tmp#&quot;}
      DNSvalue=${tmp%&quot;}
      _debug "DNSvalue: $DNSvalue"
      #     if [ "$DNSvalue" = "$txtvalue" ]; then
      # Testing value match fails.  Website is truncating the value
      # field. So for now we will assume that there is only one TXT
      # field for the sub domain and just delete it. Currently this
      # is a safe assumption.
      _freedns_delete_txt_record "$FREEDNS_COOKIE" "$DNSdataid"
      return $?
      #     fi
    fi
  done

  # If we get this far we did not find a match.
  # Not necessarily an error, but log anyway.
  _debug2 "$subdomain_csv"
  _info "Cannot delete TXT record for $fulldomain/$txtvalue. Does not exist at FreeDNS"
  return 0
}

####################  Private functions below ##################################

# usage: _freedns_login username password
# print string "cookie=value" etc.
# returns 0 success
_freedns_login() {
  username="$1"
  password="$2"
  url="https://freedns.afraid.org/zc.php?step=2"

  _debug "Login to FreeDNS as user $username"

  htmlpage="$(_post "username=$(_freedns_urlencode "$username")&password=$(_freedns_urlencode "$password")&submit=Login&action=auth" "$url")"

  if [ "$?" != "0" ]; then
    _err "FreeDNS login failed for user $username bad RC from _post"
    return 1
  fi

  cookies="$(grep -i '^Set-Cookie.*dns_cookie.*$' "$HTTP_HEADER" | _head_n 1 | tr -d "\r\n" | cut -d " " -f 2)"

  # if cookies is not empty then logon successful
  if [ -z "$cookies" ]; then
    _debug "$htmlpage"
    _err "FreeDNS login failed for user $username. Check $HTTP_HEADER file"
    return 1
  fi

  printf "%s" "$cookies"
  return 0
}

# usage _freedns_retrieve_subdomain_page login_cookies
# echo page retrieved (html)
# returns 0 success
_freedns_retrieve_subdomain_page() {
  export _H1="Cookie:$1"
  url="https://freedns.afraid.org/subdomain/"

  _debug "Retrieve subdmoain page from FreeDNS"

  htmlpage="$(_get "$url")"

  if [ "$?" != "0" ]; then
    _err "FreeDNS retrieve subdomins failed bad RC from _get"
    return 1
  fi

  if [ -z "$htmlpage" ]; then
    _err "FreeDNS returned empty subdomain page"
    return 1
  fi

  _debug2 "$htmlpage"

  printf "%s" "$htmlpage"
  return 0
}

# usage _freedns_add_txt_record login_cookies domain_id subdomain value
# returns 0 success
_freedns_add_txt_record() {
  export _H1="Cookie:$1"
  domain_id="$2"
  subdomain="$3"
  value="$(_freedns_urlencode "$4")"
  url="http://freedns.afraid.org/subdomain/save.php?step=2"

  htmlpage="$(_post "type=TXT&domain_id=$domain_id&subdomain=$subdomain&address=%22$value%22&send=Save%21" "$url")"

  if [ "$?" != "0" ]; then
    _err "FreeDNS failed to add TXT record for $subdomain bad RC from _post"
    return 1
  fi

  if ! grep "200 OK" "$HTTP_HEADER" >/dev/null; then
    _debug "$htmlpage"
    _err "FreeDNS failed to add TXT record for $subdomain. Check $HTTP_HEADER file"
    return 1
  fi
  _info "Added acme challenge TXT record for $fulldomain at FreeDNS"
  return 0
}

# usage _freedns_delete_txt_record login_cookies data_id
# returns 0 success
_freedns_delete_txt_record() {
  export _H1="Cookie:$1"
  data_id="$2"
  url="https://freedns.afraid.org/subdomain/delete2.php"

  htmlheader="$(_get "$url?data_id%5B%5D=$data_id&submit=delete+selected" "onlyheader")"

  if [ "$?" != "0" ]; then
    _err "FreeDNS failed to delete TXT record for $data_id bad RC from _get"
    return 1
  fi

  if ! _contains "$htmlheader" "200 OK"; then
    _debug "$htmlheader"
    _err "FreeDNS failed to delete TXT record $data_id"
    return 1
  fi

  _info "Deleted acme challenge TXT record for $fulldomain at FreeDNS"
  return 0
}

# urlencode magic from...
# http://askubuntu.com/questions/53770/how-can-i-encode-and-decode-percent-encoded-strings-on-the-command-line
# The _urlencode function in acme.sh does not work !
_freedns_urlencode() {
  # urlencode <string>
  length="${#1}"
  for ((i = 0; i < length; i++)); do
    c="${1:i:1}"
    case $c in
      [a-zA-Z0-9.~_-]) printf "$c" ;;
      *) printf '%%%02X' "'$c" ;;
    esac
  done
}