acme.sh/notify/smtp.sh
medmunds 06f51a5c34 Change default SMTP_SECURE to "tls"
Secure by default. Also try to minimize configuration errors.
(Many ESPs/ISPs require STARTTLS, and most support it.)
2021-03-21 16:20:32 +01:00

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#!/usr/bin/env sh
# support smtp
# Please report bugs to https://github.com/acmesh-official/acme.sh/issues/3358
# This implementation uses either curl or Python (3 or 2.7).
# (See also the "mail" notify hook, which supports other ways to send mail.)
# SMTP_FROM="from@example.com" # required
# SMTP_TO="to@example.com" # required
# SMTP_HOST="smtp.example.com" # required
# SMTP_PORT="25" # defaults to 25, 465 or 587 depending on SMTP_SECURE
# SMTP_SECURE="tls" # one of "none", "ssl" (implicit TLS, TLS Wrapper), "tls" (explicit TLS, STARTTLS)
# SMTP_USERNAME="" # set if SMTP server requires login
# SMTP_PASSWORD="" # set if SMTP server requires login
# SMTP_TIMEOUT="30" # seconds for SMTP operations to timeout
# SMTP_BIN="/path/to/python_or_curl" # default finds first of python3, python2.7, python, pypy3, pypy, curl on PATH
SMTP_SECURE_DEFAULT="tls"
SMTP_TIMEOUT_DEFAULT="30"
# subject content statuscode
smtp_send() {
SMTP_SUBJECT="$1"
SMTP_CONTENT="$2"
# UNUSED: _statusCode="$3" # 0: success, 1: error 2($RENEW_SKIP): skipped
# Load and validate config:
SMTP_BIN="$(_readaccountconf_mutable_default SMTP_BIN)"
if [ -n "$SMTP_BIN" ] && ! _exists "$SMTP_BIN"; then
_err "SMTP_BIN '$SMTP_BIN' does not exist."
return 1
fi
if [ -z "$SMTP_BIN" ]; then
# Look for a command that can communicate with an SMTP server.
# (Please don't add sendmail, ssmtp, mutt, mail, or msmtp here.
# Those are already handled by the "mail" notify hook.)
for cmd in python3 python2.7 python pypy3 pypy curl; do
if _exists "$cmd"; then
SMTP_BIN="$cmd"
break
fi
done
if [ -z "$SMTP_BIN" ]; then
_err "The smtp notify-hook requires curl or Python, but can't find any."
_err 'If you have one of them, define SMTP_BIN="/path/to/curl_or_python".'
_err 'Otherwise, see if you can use the "mail" notify-hook instead.'
return 1
fi
fi
_debug SMTP_BIN "$SMTP_BIN"
_saveaccountconf_mutable_default SMTP_BIN "$SMTP_BIN"
SMTP_FROM="$(_readaccountconf_mutable_default SMTP_FROM)"
SMTP_FROM="$(_clean_email_header "$SMTP_FROM")"
if [ -z "$SMTP_FROM" ]; then
_err "You must define SMTP_FROM as the sender email address."
return 1
fi
if _email_has_display_name "$SMTP_FROM"; then
_err "SMTP_FROM must be only a simple email address (sender@example.com)."
_err "Change your SMTP_FROM='$SMTP_FROM' to remove the display name."
return 1
fi
_debug SMTP_FROM "$SMTP_FROM"
_saveaccountconf_mutable_default SMTP_FROM "$SMTP_FROM"
SMTP_TO="$(_readaccountconf_mutable_default SMTP_TO)"
SMTP_TO="$(_clean_email_header "$SMTP_TO")"
if [ -z "$SMTP_TO" ]; then
_err "You must define SMTP_TO as the recipient email address(es)."
return 1
fi
if _email_has_display_name "$SMTP_TO"; then
_err "SMTP_TO must be only simple email addresses (to@example.com,to2@example.com)."
_err "Change your SMTP_TO='$SMTP_TO' to remove the display name(s)."
return 1
fi
_debug SMTP_TO "$SMTP_TO"
_saveaccountconf_mutable_default SMTP_TO "$SMTP_TO"
SMTP_HOST="$(_readaccountconf_mutable_default SMTP_HOST)"
if [ -z "$SMTP_HOST" ]; then
_err "You must define SMTP_HOST as the SMTP server hostname."
return 1
fi
_debug SMTP_HOST "$SMTP_HOST"
_saveaccountconf_mutable_default SMTP_HOST "$SMTP_HOST"
SMTP_SECURE="$(_readaccountconf_mutable_default SMTP_SECURE "$SMTP_SECURE_DEFAULT")"
case "$SMTP_SECURE" in
"none") smtp_port_default="25" ;;
"ssl") smtp_port_default="465" ;;
"tls") smtp_port_default="587" ;;
*)
_err "Invalid SMTP_SECURE='$SMTP_SECURE'. It must be 'ssl', 'tls' or 'none'."
return 1
;;
esac
_debug SMTP_SECURE "$SMTP_SECURE"
_saveaccountconf_mutable_default SMTP_SECURE "$SMTP_SECURE" "$SMTP_SECURE_DEFAULT"
SMTP_PORT="$(_readaccountconf_mutable_default SMTP_PORT "$smtp_port_default")"
case "$SMTP_PORT" in
*[!0-9]*)
_err "Invalid SMTP_PORT='$SMTP_PORT'. It must be a port number."
return 1
;;
esac
_debug SMTP_PORT "$SMTP_PORT"
_saveaccountconf_mutable_default SMTP_PORT "$SMTP_PORT" "$smtp_port_default"
SMTP_USERNAME="$(_readaccountconf_mutable_default SMTP_USERNAME)"
_debug SMTP_USERNAME "$SMTP_USERNAME"
_saveaccountconf_mutable_default SMTP_USERNAME "$SMTP_USERNAME"
SMTP_PASSWORD="$(_readaccountconf_mutable_default SMTP_PASSWORD)"
_secure_debug SMTP_PASSWORD "$SMTP_PASSWORD"
_saveaccountconf_mutable_default SMTP_PASSWORD "$SMTP_PASSWORD"
SMTP_TIMEOUT="$(_readaccountconf_mutable_default SMTP_TIMEOUT "$SMTP_TIMEOUT_DEFAULT")"
_debug SMTP_TIMEOUT "$SMTP_TIMEOUT"
_saveaccountconf_mutable_default SMTP_TIMEOUT "$SMTP_TIMEOUT" "$SMTP_TIMEOUT_DEFAULT"
SMTP_X_MAILER="$(_clean_email_header "$PROJECT_NAME $VER --notify-hook smtp")"
# Run with --debug 2 (or above) to echo the transcript of the SMTP session.
# Careful: this may include SMTP_PASSWORD in plaintext!
if [ "${DEBUG:-$DEBUG_LEVEL_NONE}" -ge "$DEBUG_LEVEL_2" ]; then
SMTP_SHOW_TRANSCRIPT="True"
else
SMTP_SHOW_TRANSCRIPT=""
fi
SMTP_SUBJECT=$(_clean_email_header "$SMTP_SUBJECT")
_debug SMTP_SUBJECT "$SMTP_SUBJECT"
_debug SMTP_CONTENT "$SMTP_CONTENT"
# Send the message:
case "$(basename "$SMTP_BIN")" in
curl) _smtp_send=_smtp_send_curl ;;
py*) _smtp_send=_smtp_send_python ;;
*)
_err "Can't figure out how to invoke '$SMTP_BIN'."
_err "Check your SMTP_BIN setting."
return 1
;;
esac
if ! smtp_output="$($_smtp_send)"; then
_err "Error sending message with $SMTP_BIN."
if [ -n "$smtp_output" ]; then
_err "$smtp_output"
fi
return 1
fi
return 0
}
# Strip CR and NL from text to prevent MIME header injection
# text
_clean_email_header() {
printf "%s" "$(echo "$1" | tr -d "\r\n")"
}
# Simple check for display name in an email address (< > or ")
# email
_email_has_display_name() {
_email="$1"
expr "$_email" : '^.*[<>"]' >/dev/null
}
##
## curl smtp sending
##
# Send the message via curl using SMTP_* variables
_smtp_send_curl() {
# Build curl args in $@
case "$SMTP_SECURE" in
none)
set -- --url "smtp://${SMTP_HOST}:${SMTP_PORT}"
;;
ssl)
set -- --url "smtps://${SMTP_HOST}:${SMTP_PORT}"
;;
tls)
set -- --url "smtp://${SMTP_HOST}:${SMTP_PORT}" --ssl-reqd
;;
*)
# This will only occur if someone adds a new SMTP_SECURE option above
# without updating this code for it.
_err "Unhandled SMTP_SECURE='$SMTP_SECURE' in _smtp_send_curl"
_err "Please re-run with --debug and report a bug."
return 1
;;
esac
set -- "$@" \
--upload-file - \
--mail-from "$SMTP_FROM" \
--max-time "$SMTP_TIMEOUT"
# Burst comma-separated $SMTP_TO into individual --mail-rcpt args.
_to="${SMTP_TO},"
while [ -n "$_to" ]; do
_rcpt="${_to%%,*}"
_to="${_to#*,}"
set -- "$@" --mail-rcpt "$_rcpt"
done
_smtp_login="${SMTP_USERNAME}:${SMTP_PASSWORD}"
if [ "$_smtp_login" != ":" ]; then
set -- "$@" --user "$_smtp_login"
fi
if [ "$SMTP_SHOW_TRANSCRIPT" = "True" ]; then
set -- "$@" --verbose
else
set -- "$@" --silent --show-error
fi
raw_message="$(_smtp_raw_message)"
_debug2 "curl command:" "$SMTP_BIN" "$*"
_debug2 "raw_message:\n$raw_message"
echo "$raw_message" | "$SMTP_BIN" "$@"
}
# Output an RFC-822 / RFC-5322 email message using SMTP_* variables.
# (This assumes variables have already been cleaned for use in email headers.)
_smtp_raw_message() {
echo "From: $SMTP_FROM"
echo "To: $SMTP_TO"
echo "Subject: $(_mime_encoded_word "$SMTP_SUBJECT")"
echo "Date: $(_rfc2822_date)"
echo "Content-Type: text/plain; charset=utf-8"
echo "X-Mailer: $SMTP_X_MAILER"
echo
echo "$SMTP_CONTENT"
}
# Convert text to RFC-2047 MIME "encoded word" format if it contains non-ASCII chars
# text
_mime_encoded_word() {
_text="$1"
# (regex character ranges like [a-z] can be locale-dependent; enumerate ASCII chars to avoid that)
_ascii='] $`"'"[!#%&'()*+,./0123456789:;<=>?@ABCDEFGHIJKLMNOPQRSTUVWXYZ~^_abcdefghijklmnopqrstuvwxyz{|}~-"
if expr "$_text" : "^.*[^$_ascii]" >/dev/null; then
# At least one non-ASCII char; convert entire thing to encoded word
printf "%s" "=?UTF-8?B?$(printf "%s" "$_text" | _base64)?="
else
# Just printable ASCII, no conversion needed
printf "%s" "$_text"
fi
}
# Output current date in RFC-2822 Section 3.3 format as required in email headers
# (e.g., "Mon, 15 Feb 2021 14:22:01 -0800")
_rfc2822_date() {
# Notes:
# - this is deliberately not UTC, because it "SHOULD express local time" per spec
# - the spec requires weekday and month in the C locale (English), not localized
# - this date format specifier has been tested on Linux, Mac, Solaris and FreeBSD
_old_lc_time="$LC_TIME"
LC_TIME=C
date +'%a, %-d %b %Y %H:%M:%S %z'
LC_TIME="$_old_lc_time"
}
##
## Python smtp sending
##
# Send the message via Python using SMTP_* variables
_smtp_send_python() {
_debug "Python version" "$("$SMTP_BIN" --version 2>&1)"
# language=Python
"$SMTP_BIN" <<PYTHON
# This code is meant to work with either Python 2.7.x or Python 3.4+.
try:
try:
from email.message import EmailMessage
from email.policy import default as email_policy_default
except ImportError:
# Python 2 (or < 3.3)
from email.mime.text import MIMEText as EmailMessage
email_policy_default = None
from email.utils import formatdate as rfc2822_date
from smtplib import SMTP, SMTP_SSL, SMTPException
from socket import error as SocketError
except ImportError as err:
print("A required Python standard package is missing. This system may have"
" a reduced version of Python unsuitable for sending mail: %s" % err)
exit(1)
show_transcript = """$SMTP_SHOW_TRANSCRIPT""" == "True"
smtp_host = """$SMTP_HOST"""
smtp_port = int("""$SMTP_PORT""")
smtp_secure = """$SMTP_SECURE"""
username = """$SMTP_USERNAME"""
password = """$SMTP_PASSWORD"""
timeout=int("""$SMTP_TIMEOUT""") # seconds
x_mailer="""$SMTP_X_MAILER"""
from_email="""$SMTP_FROM"""
to_emails="""$SMTP_TO""" # can be comma-separated
subject="""$SMTP_SUBJECT"""
content="""$SMTP_CONTENT"""
try:
msg = EmailMessage(policy=email_policy_default)
msg.set_content(content)
except (AttributeError, TypeError):
# Python 2 MIMEText
msg = EmailMessage(content)
msg["Subject"] = subject
msg["From"] = from_email
msg["To"] = to_emails
msg["Date"] = rfc2822_date(localtime=True)
msg["X-Mailer"] = x_mailer
smtp = None
try:
if smtp_secure == "ssl":
smtp = SMTP_SSL(smtp_host, smtp_port, timeout=timeout)
else:
smtp = SMTP(smtp_host, smtp_port, timeout=timeout)
smtp.set_debuglevel(show_transcript)
if smtp_secure == "tls":
smtp.starttls()
if username or password:
smtp.login(username, password)
smtp.sendmail(msg["From"], msg["To"].split(","), msg.as_string())
except SMTPException as err:
# Output just the error (skip the Python stack trace) for SMTP errors
print("Error sending: %r" % err)
exit(1)
except SocketError as err:
print("Error connecting to %s:%d: %r" % (smtp_host, smtp_port, err))
exit(1)
finally:
if smtp is not None:
smtp.quit()
PYTHON
}
##
## Conf helpers
##
#_readaccountconf_mutable_default name default_value
# Given a name like MY_CONF:
# - if MY_CONF is set and non-empty, output $MY_CONF
# - if MY_CONF is set _empty_, output $default_value
# (lets user `export MY_CONF=` to clear previous saved value
# and return to default, without user having to know default)
# - otherwise if _readaccountconf_mutable MY_CONF is non-empty, return that
# (value of SAVED_MY_CONF from account.conf)
# - otherwise output $default_value
_readaccountconf_mutable_default() {
_name="$1"
_default_value="$2"
eval "_value=\"\$$_name\""
eval "_name_is_set=\"\${${_name}+true}\""
# ($_name_is_set is "true" if $$_name is set to anything, including empty)
if [ -z "${_value}" ] && [ "${_name_is_set:-}" != "true" ]; then
_value="$(_readaccountconf_mutable "$_name")"
fi
if [ -z "${_value}" ]; then
_value="$_default_value"
fi
printf "%s" "$_value"
}
#_saveaccountconf_mutable_default name value default_value base64encode
# Like _saveaccountconf_mutable, but if value is default_value
# then _clearaccountconf_mutable instead
_saveaccountconf_mutable_default() {
_name="$1"
_value="$2"
_default_value="$3"
_base64encode="$4"
if [ "$_value" != "$_default_value" ]; then
_saveaccountconf_mutable "$_name" "$_value" "$_base64encode"
else
_clearaccountconf_mutable "$_name"
fi
}