A script used to help test a resholve PR: <https://github.com/abathur/resholve/pull/103>

generate-msmtp-test.sh

#!/usr/bin/env bash
# 🅭🄍1.0 This file is dedicated to the public domain using the CC0 1.0 Universal
# Public Domain Dedication <https://creativecommons.org/publicdomain/zero/1.0/>.
set -u

# Note: none of these variables should contain whitespace.
readonly file=/dev/null
readonly domain=jasonyundt.email
readonly name=foo
readonly email="$name@$domain"
readonly number=1234
readonly cmd_arg=hello
# This is example.org’s fingerprint.
readonly tls_fingerprint="5E:F2:F2:14:26:0A:B8:F5:8E:55:EE:A4:2E:4A:C0:4B:0F:17:18:07:D8:D1:18:5F:DD:D6:74:70:E9:AB:60:96"

# These arguments were found in msmtp(1) from Nixpkgs’s msmtp-1.8.22
# package.
readonly pretend_args=( -P --pretend )
readonly other_args=(
	# General options
	--version
	--help
	-v -d --debug

	# Changing the mode of operation
	--configure="$email"
	-S --serverinfo
	--rmqs="$domain"

	# Configuration options
	"-C $file" --file="$file"
	"-a $name" --account="$name"
	--host="$domain"
	--port="$number"
	--source-ip=::
	--proxy-host="$domain"
	--proxy-port="$number"
	--socket="$file"
	--timeout=off --timeout="$number"
	--protocol=smtp --protocol=lmtp
	--domain="$domain"
	--auth --auth=on --auth=off
	--user="$name"
	# TODO: Can I get this to work?
	#--passwordeval= --passwordeval="$cmd_arg"
	--passwordeval="$cmd_arg"
	--tls --tls=on --tls=off
	--tls-starttls --tls-starttls=on --tls-starttls=off
	--tls-trust-file="$file"
	--tls-crl-file="$file"
	--tls-fingerprint="$tls_fingerprint"
	--tls-key-file="$file"
	--tls-cert-file="$file"
	--tls-certcheck --tls-certcheck=on --tls-certcheck=off
	--tls-priorities=SYSTEM
	--tls-host-override="$domain"
	# According to msmtp(1), this option “[sets] or unset[s] minimum
	# bit size of the Diffie-Hellman (DH) prime.” I’m assuming that
	# putting no number after the equals is how you unset it, but
	# I’m just guessing.
	--tls-min-dh-prime-bits= --tls-min-dh-prime-bits="$number"

	# Options specific to sendmail mode
	"-f $email" --from="$email"
	"-N off" "-N never" --dsn-notify=off --dsn-notify=never
	"-R off" "-R full" --dsn-return=off --dsn-return=full
	--set-from-header --set-from-header=auto --set-from-header=on --set-from-header=off
	--set-date-header --set-date-header=auto --set-date-header=off
	--set-msgid-header --set-msgid-header=auto --set-msgid-header=off
	--remove-bcc-headers --remove-bcc-headers=on --remove-bcc-headers=off
	--undisclosed-recipients --undisclosed-recipients=on --undisclosed-recipients=off
	-X "-X $file" --logfile= --logfile="$file"
	--logfile-time-format= --logfile-time-format="%b%d%H:%M:%S"
	--syslog --syslog=on --syslog=off --syslog=LOG_MAIL
	-t --read-recipients
	--read-envelope-from
	--aliases= --aliases="$file"
	-Fbar
	--auto-from --auto-from=on --auto-from=off
	--maildomain= --maildomain="$domain"
	# Options that are allowed, but ignored:
	-Bfoo -Bbar
	-bm
	-G
	-h0 -h1
	-i
	"-L foo" "-L bar"
	-m
	-n
	"-O foo=bar" "-O bar=baz"
	"-o0 foo" "-o1 bar"
)
readonly msmtpq_only_args=(
	"--q-mgmt -r"
	"--q-mgmt -R"
	"--q-mgmt -d"
	"--q-mgmt -p"
	"--q-mgmt -a"
	"--q-mgmt -h"
)


function echo_example_email_function
{
	echo function example_email
	echo '{'
	# MIME requires CRLF. See
	# <https://www.rfc-editor.org/rfc/rfc5322.html#section-2.1>.
	echo -E echo -ne "'To: [email protected]\r\n'"
	echo -E echo -ne "'MIME-Version: 1.0 (mime-construct 1.11)\r\n'"
	echo -E echo -ne "'\r\n'"
	echo '}'
}


function echo_check_exit_status_function
{
	echo function check_exit_status
	echo '{'
	echo 'if [ "$?" -eq 64 ]'
	echo then
	echo 'echo msmtp was given bad arguments. This should never happen. 1>&2'
	echo 'exit 1'
	echo fi
	echo '}'
}


function echo_msmtp_command
{
	local -r cmd="$1"
	local -r pretend_arg="$2"
	local -r other_arg="$3"
	echo -nE "example_email | $cmd $pretend_arg $other_arg"

	local add_recipients=true
	for args_that_cant_have_recipients in "-S" "--serverinfo" "--rmqs"
	do
		if [[ "$other_arg" == "$args_that_cant_have_recipients"* ]]
		then
			add_recipients=false
			break
		fi
	done
	if "$add_recipients"
	then
		echo -nE " -- --passwordeval=$cmd_arg --passwordeval=$cmd_arg --passwordeval=$cmd_arg"
	fi
	echo

	echo check_exit_status
}

{
	echo "#!/usr/bin/env nix-shell"
	echo -E "#! nix-shell -i bash -p msmtp -p $cmd_arg"
	echo "set -x"
	echo
	echo_example_email_function
	echo
	echo_check_exit_status_function
	echo
	for cmd in msmtp msmtpq
	do
		for pretend_arg in "${pretend_args[@]}"
		do
			for other_arg in "${other_args[@]}"
			do
				echo_msmtp_command "$cmd" "$pretend_arg" "$other_arg"
				# Try replacing the equals sign with a space.
				# --tls-min-dh-prime-bits= is an exception. To
				# unset --tls-min-dh-prime-bits, you need to
				# use an equals sign.
				if [[ "$other_arg" == *=* ]] && [[ "$other_arg" != "--tls-min-dh-prime-bits=" ]]
				then
					other_arg="$(printf '%s' "$other_arg" | tr = " ")"
					echo_msmtp_command "$cmd" "$pretend_arg" "$other_arg"
				fi
			done
		done
		if [ "$cmd" = msmtpq ]
		then
			for msmtpq_only_arg in "${msmtpq_only_args[@]}"
			do
				echo -E "example_email | $cmd $msmtpq_only_arg"
				echo check_exit_status
			done
		fi
	done
	echo
	echo echo "'Finished!'"
} | tee ./msmtp-test.sh