#!/usr/bin/sh

 # install demo build dependencies

 set -u

 PKG_URL_ROOT="${PKG_URL_ROOT:-https://rwest.io/otom8/packy/bundle}"

 PKG_NAME="demo_build_deps"

 say() {printf 'babel-installer: %s\n' "$1"}

 err() {say "$1" >&2; exit 1}

 need_cmd() {

     if ! check_cmd "$1"; then

         err "need '$1' (command not found)"

     fi}

 check_cmd() {command -v "$1" > /dev/null 2>&1}

 ensure() {if ! "$@"; then err "command failed: $*"; fi}

 ignore() {"$@"}

 main () {

     need_cmd chmod

     need_cmd mkdir

     need_cmd rm

     get_architecture || return 1

     local _arch="$RETVAL"

     assert_nz "$_arch" "arch"

     # no extension unless on windows

     local _ext=""

     case "$_arch" in

         *windows*)

             _ext=".exe"

             ;;

     esac

   local _url="${PKG_URL_ROOT}/bin/dist/${_arch}/${PKG_NAME}${_ext}"

     local _dir

     _dir="$(ensure mktemp -d)"

     local _file="${_dir}/${PKG_NAME}${_ext}"

     local _ansi_escapes_are_valid=false

     if [ -t 2 ]; then

         if [ "${TERM+set}" = 'set' ]; then

             case "$TERM" in

                 xterm*|rxvt*|urxvt*|linux*|vt*)

                     _ansi_escapes_are_valid=true

                 ;;

             esac

         fi

     fi

     # check if we have to use /dev/tty to prompt the user

     local need_tty=yes

     for arg in "$@"; do

         case "$arg" in

             q)

                 # user wants to skip the prompt --

                 # we don't need /dev/tty

                 need_tty=no

                 ;;

             *)

                 ;;

         esac

     done

     if $_ansi_escapes_are_valid; then

         printf "\33[1minfo:\33[0m downloading $PKG_NAME\n" 1>&2

     else

         printf '%s\n' 'info: downloading $PKG_NAME' 1>&2

     fi

     ensure mkdir -p "$_dir"

     ensure downloader "$_url" "$_file" "$_arch"

     ensure chmod u+x "$_file"

     if [ ! -x "$_file" ]; then

         printf '%s\n' "Cannot execute $_file (likely because of mounting /tmp as noexec)." 1>&2

         printf '%s\n' "Please copy the file to a location where you can execute binaries and run ./${PKG_NAME}${_ext}." 1>&2

         exit 1

     fi

     if [ "$need_tty" = "yes" ]; then

         # The installer is going to want to ask for confirmation by

         # reading stdin.  This script was piped into `sh` though and

         # doesn't have stdin to pass to its children. Instead we're going

         # to explicitly connect /dev/tty to the installer's stdin.

         if [ ! -t 1 ]; then

             err "Unable to run interactively. Run with -y to accept defaults"

         fi

         ignore "$_file" "$@" < /dev/tty

     else

         ignore "$_file" "$@"

     fi

     local _retval=$?

     ignore rm "$_file"

     ignore rmdir "$_dir"

     return "$_retval"

 }

 dl() { # curl || wget

     local _dld

     local _ciphersuites

     local _err

     local _status

     if check_cmd curl; then

         _dld=curl

     elif check_cmd wget; then

         _dld=wget

     else

         _dld='curl or wget' # to be used in error message of need_cmd

     fi

     if [ "$1" = --check ]; then

         need_cmd "$_dld"

     elif [ "$_dld" = curl ]; then

         get_ciphersuites_for_curl

         _ciphersuites="$RETVAL"

         if [ -n "$_ciphersuites" ]; then

             _err=$(curl --proto '=https' --tlsv1.2 --ciphers "$_ciphersuites" --silent --show-error --fail --location "$1" --output "$2" 2>&1)

             _status=$?

         else

             echo "Warning: Not enforcing strong cipher suites for TLS, this is potentially less secure"

             if ! check_help_for "$3" curl --proto --tlsv1.2; then

                 echo "Warning: Not enforcing TLS v1.2, this is potentially less secure"

                 _err=$(curl --silent --show-error --fail --location "$1" --output "$2" 2>&1)

                 _status=$?

             else

                 _err=$(curl --proto '=https' --tlsv1.2 --silent --show-error --fail --location "$1" --output "$2" 2>&1)

                 _status=$?

             fi

         fi

         if [ -n "$_err" ]; then

             echo "$_err" >&2

             if echo "$_err" | grep -q 404$; then

                 err "installer for platform '$3' not found 8^C - ask ellis to support your platform"

             fi

         fi

         return $_status

     elif [ "$_dld" = wget ]; then

         get_ciphersuites_for_wget

         _ciphersuites="$RETVAL"

         if [ -n "$_ciphersuites" ]; then

             _err=$(wget --https-only --secure-protocol=TLSv1_2 --ciphers "$_ciphersuites" "$1" -O "$2" 2>&1)

             _status=$?

         else

             echo "Warning: Not enforcing strong cipher suites for TLS, this is potentially less secure"

             if ! check_help_for "$3" wget --https-only --secure-protocol; then

                 echo "Warning: Not enforcing TLS v1.2, this is potentially less secure"

                 _err=$(wget "$1" -O "$2" 2>&1)

                 _status=$?

             else

                 _err=$(wget --https-only --secure-protocol=TLSv1_2 "$1" -O "$2" 2>&1)

                 _status=$?

             fi

         fi

         if [ -n "$_err" ]; then

             echo "$_err" >&2

             if echo "$_err" | grep -q ' 404 Not Found$'; then

                 err "installer for platform '$3' not found!"

             fi

         fi

         return $_status

     else

         err "Unknown downloader"   # should not reach here

     fi

 }

 check_help_for() {

     local _arch

     local _cmd

     local _arg

     _arch="$1"

     shift

     _cmd="$1"

     shift

     local _category

     if "$_cmd" --help | grep -q 'For all options use the manual or "--help all".'; then

       _category="all"

     else

       _category=""

     fi

     case "$_arch" in

         *darwin*)

         if check_cmd sw_vers; then

             case $(sw_vers -productVersion) in

                 10.*)

                     # If we're running on macOS, older than 10.13, then we always

                     # fail to find these options to force fallback

                     if [ "$(sw_vers -productVersion | cut -d. -f2)" -lt 13 ]; then

                         # Older than 10.13

                         echo "Warning: Detected macOS platform older than 10.13"

                         return 1

                     fi

                     ;;

                 11.*)

                     # We assume Big Sur will be OK for now

                     ;;

                 *)

                     # Unknown product version, warn and continue

                     echo "Warning: Detected unknown macOS major version: $(sw_vers -productVersion)"

                     echo "Warning TLS capabilities detection may fail"

                     ;;

             esac

         fi

         ;;

     esac

     for _arg in "$@"; do

         if ! "$_cmd" --help $_category | grep -q -- "$_arg"; then

             return 1

         fi

     done

     true # not strictly needed

 }

 # Return cipher suite string specified by user, otherwise return strong TLS 1.2-1.3 cipher suites

 # if support by local tools is detected. Detection currently supports these curl backends: 

 # GnuTLS and OpenSSL (possibly also LibreSSL and BoringSSL). Return value can be empty.

 get_ciphersuites_for_curl() {

     if [ -n "${BABEL_TLS_CIPHERSUITES-}" ]; then

         # user specified custom cipher suites, assume they know what they're doing

         RETVAL="$BABEL_TLS_CIPHERSUITES"

         return

     fi

     local _openssl_syntax="no"

     local _gnutls_syntax="no"

     local _backend_supported="yes"

     if curl -V | grep -q ' OpenSSL/'; then

         _openssl_syntax="yes"

     elif curl -V | grep -iq ' LibreSSL/'; then

         _openssl_syntax="yes"

     elif curl -V | grep -iq ' BoringSSL/'; then

         _openssl_syntax="yes"

     elif curl -V | grep -iq ' GnuTLS/'; then

         _gnutls_syntax="yes"

     else

         _backend_supported="no"

     fi

     local _args_supported="no"

     if [ "$_backend_supported" = "yes" ]; then

         # "unspecified" is for arch, allows for possibility old OS using macports, homebrew, etc.

         if check_help_for "notspecified" "curl" "--tlsv1.2" "--ciphers" "--proto"; then

             _args_supported="yes"

         fi

     fi

     local _cs=""

     if [ "$_args_supported" = "yes" ]; then

         if [ "$_openssl_syntax" = "yes" ]; then

             _cs=$(get_strong_ciphersuites_for "openssl")

         elif [ "$_gnutls_syntax" = "yes" ]; then

             _cs=$(get_strong_ciphersuites_for "gnutls")

         fi

     fi

     RETVAL="$_cs"

 }

 # Return cipher suite string specified by user, otherwise return strong TLS 1.2-1.3 cipher suites

 # if support by local tools is detected. Detection currently supports these wget backends: 

 # GnuTLS and OpenSSL (possibly also LibreSSL and BoringSSL). Return value can be empty.

 get_ciphersuites_for_wget() {

     if [ -n "${BABEL_TLS_CIPHERSUITES-}" ]; then

         # user specified custom cipher suites, assume they know what they're doing

         RETVAL="$BABEL_TLS_CIPHERSUITES"

         return

     fi

     local _cs=""

     if wget -V | grep -q '\-DHAVE_LIBSSL'; then

         # "unspecified" is for arch, allows for possibility old OS using macports, homebrew, etc.

         if check_help_for "notspecified" "wget" "TLSv1_2" "--ciphers" "--https-only" "--secure-protocol"; then

             _cs=$(get_strong_ciphersuites_for "openssl")

         fi

     elif wget -V | grep -q '\-DHAVE_LIBGNUTLS'; then

         # "unspecified" is for arch, allows for possibility old OS using macports, homebrew, etc.

         if check_help_for "notspecified" "wget" "TLSv1_2" "--ciphers" "--https-only" "--secure-protocol"; then

             _cs=$(get_strong_ciphersuites_for "gnutls")

         fi

     fi

     RETVAL="$_cs"

 }

 # Return strong TLS 1.2-1.3 cipher suites in OpenSSL or GnuTLS syntax. TLS 1.2 

 # excludes non-ECDHE and non-AEAD cipher suites. DHE is excluded due to bad 

 # DH params often found on servers (see RFC 7919). Sequence matches or is

 # similar to Firefox 68 ESR with weak cipher suites disabled via about:config.  

 # $1 must be openssl or gnutls.

 get_strong_ciphersuites_for() {

     if [ "$1" = "openssl" ]; then

         # OpenSSL is forgiving of unknown values, no problems with TLS 1.3 values on versions that don't support it yet.

         echo "TLS_AES_128_GCM_SHA256:TLS_CHACHA20_POLY1305_SHA256:TLS_AES_256_GCM_SHA384:ECDHE-ECDSA-AES128-GCM-SHA256:ECDHE-RSA-AES128-GCM-SHA256:ECDHE-ECDSA-CHACHA20-POLY1305:ECDHE-RSA-CHACHA20-POLY1305:ECDHE-ECDSA-AES256-GCM-SHA384:ECDHE-RSA-AES256-GCM-SHA384"

     elif [ "$1" = "gnutls" ]; then

         # GnuTLS isn't forgiving of unknown values, so this may require a GnuTLS version that supports TLS 1.3 even if wget doesn't.

         # Begin with SECURE128 (and higher) then remove/add to build cipher suites. Produces same 9 cipher suites as OpenSSL but in slightly different order.

         echo "SECURE128:-VERS-SSL3.0:-VERS-TLS1.0:-VERS-TLS1.1:-VERS-DTLS-ALL:-CIPHER-ALL:-MAC-ALL:-KX-ALL:+AEAD:+ECDHE-ECDSA:+ECDHE-RSA:+AES-128-GCM:+CHACHA20-POLY1305:+AES-256-GCM"

     fi 

 }

 main "$@" || exit 1