lix-installer/nix-installer.sh
Ana Hobden 6b3a84002e
Add a friendly top comment about nix-installer.sh (#216)
* Add a friendly top comment about nix-installer.sh

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* add a missing 'that'
2023-01-31 18:12:19 +00:00

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#!/bin/sh
# shellcheck shell=dash
# If you need an offline install, or you'd prefer to run the binary directly, head to
# https://github.com/DeterminateSystems/nix-installer/releases then pick the version and platform
# most appropriate for your deployment target.
#
# This is just a little script that selects and downloads the right `nix-installer`. It does
# platform detection, downloads the installer, and runs it; that's it.
#
# It runs on Unix shells like {a,ba,da,k,z}sh. It uses the common `local`
# extension. Note: Most shells limit `local` to 1 var per line, contra bash.
# This script is based off https://github.com/rust-lang/rustup/blob/8f6b53628ad996ad86f9c6225fa500cddf860905/rustup-init.sh
if [ "$KSH_VERSION" = 'Version JM 93t+ 2010-03-05' ]; then
# The version of ksh93 that ships with many illumos systems does not
# support the "local" extension. Print a message rather than fail in
# subtle ways later on:
echo 'nix-installer does not work with this ksh93 version; please try bash!' >&2
exit 1
fi
set -u
# If NIX_INSTALLER_FORCE_ALLOW_HTTP is unset or empty, default it.
NIX_INSTALLER_BINARY_ROOT="${NIX_INSTALLER_BINARY_ROOT:-https://install.determinate.systems/nix}"
main() {
downloader --check
need_cmd uname
need_cmd mktemp
need_cmd chmod
need_cmd mkdir
need_cmd rm
need_cmd rmdir
get_architecture || return 1
local _arch="$RETVAL"
assert_nz "$_arch" "arch"
local _ext=""
case "$_arch" in
*windows*)
_ext=".exe"
;;
esac
local _url="${NIX_INSTALLER_OVERRIDE_URL-${NIX_INSTALLER_BINARY_ROOT}/nix-installer-${_arch}${_ext}}"
local _dir
if ! _dir="$(ensure mktemp -d)"; then
# Because the previous command ran in a subshell, we must manually
# propagate exit status.
exit 1
fi
local _file="${_dir}/nix-installer${_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
--no-confirm)
need_tty=no
;;
*)
continue
;;
esac
done
if [ "${NIX_INSTALLER_NO_CONFIRM-}" ]; then
need_tty=no
fi
if $_ansi_escapes_are_valid; then
printf "\33[1minfo:\33[0m downloading installer \33[4m%s\33[0m\n" "$_url" 1>&2
else
printf 'info: downloading installer (%s)\n' "$_url" 1>&2
fi
ensure mkdir -p "$_dir"
ensure downloader "$_url" "$_file" "$_arch"
ensure chmod u+x "$_file"
if [ ! -x "$_file" ]; then
printf '%s\n' "Cannot execute $_file (likely because of mounting /tmp as noexec)." 1>&2
printf '%s\n' "Please copy the file to a location where you can execute binaries and run ./nix-installer${_ext}." 1>&2
exit 1
fi
if [ "$need_tty" = "yes" ] && [ ! -t 0 ]; then
# The installer is going to want to ask for confirmation by
# reading stdin. This script was piped into `sh` though and
# doesn't have stdin to pass to its children. Instead we're going
# to explicitly connect /dev/tty to the installer's stdin.
if [ ! -t 1 ]; then
err "Unable to run interactively. Run with --no-confirm to accept defaults, --help for additional options"
fi
ignore "$_file" "$@" < /dev/tty
else
ignore "$_file" "$@"
fi
local _retval=$?
ignore rm "$_file"
ignore rmdir "$_dir"
return "$_retval"
}
check_proc() {
# Check for /proc by looking for the /proc/self/exe link
# This is only run on Linux
if ! test -L /proc/self/exe ; then
err "fatal: Unable to find /proc/self/exe. Is /proc mounted? Installation cannot proceed without /proc."
fi
}
get_architecture() {
local _ostype _cputype _arch
_ostype="$(uname -s)"
_cputype="$(uname -m)"
if [ "$_ostype" = Linux ]; then
if [ "$(uname -o)" = Android ]; then
_ostype=Android
fi
if ldd --version 2>&1 | grep -q 'musl'; then
_clibtype="musl"
fi
fi
if [ "$_ostype" = Darwin ] && [ "$_cputype" = i386 ]; then
# Darwin `uname -m` lies
if sysctl hw.optional.x86_64 | grep -q ': 1'; then
_cputype=x86_64
fi
fi
if [ "$_ostype" = SunOS ]; then
# Both Solaris and illumos presently announce as "SunOS" in "uname -s"
# so use "uname -o" to disambiguate. We use the full path to the
# system uname in case the user has coreutils uname first in PATH,
# which has historically sometimes printed the wrong value here.
if [ "$(/usr/bin/uname -o)" = illumos ]; then
_ostype=illumos
fi
# illumos systems have multi-arch userlands, and "uname -m" reports the
# machine hardware name; e.g., "i86pc" on both 32- and 64-bit x86
# systems. Check for the native (widest) instruction set on the
# running kernel:
if [ "$_cputype" = i86pc ]; then
_cputype="$(isainfo -n)"
fi
fi
case "$_ostype" in
Linux)
check_proc
_ostype=linux
;;
Darwin)
_ostype=darwin
;;
*)
err "unrecognized OS type: $_ostype"
;;
esac
case "$_cputype" in
aarch64 | arm64)
_cputype=aarch64
;;
x86_64 | x86-64 | x64 | amd64)
_cputype=x86_64
;;
*)
err "unknown CPU type: $_cputype"
;;
esac
_arch="${_cputype}-${_ostype}"
RETVAL="$_arch"
}
say() {
printf 'nix-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
}
assert_nz() {
if [ -z "$1" ]; then err "assert_nz $2"; fi
}
# Run a command that should never fail. If the command fails execution
# will immediately terminate with an error showing the failing
# command.
ensure() {
if ! "$@"; then err "command failed: $*"; fi
}
# This is just for indicating that commands' results are being
# intentionally ignored. Usually, because it's being executed
# as part of error handling.
ignore() {
"$@"
}
# This wraps curl or wget. Try curl first, if not installed,
# use wget instead.
downloader() {
local _dld
local _ciphersuites
local _err
local _status
local _retry
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 [ "$_dld" = curl ]; then
check_curl_for_retry_support
_retry="$RETVAL"
get_ciphersuites_for_curl
_ciphersuites="$RETVAL"
if [ -n "$_ciphersuites" ]; then
if [ -n "${NIX_INSTALLER_FORCE_ALLOW_HTTP-}" ]; then
_err=$(curl $_retry --silent --show-error --fail --location "$1" --output "$2" 2>&1)
else
_err=$(curl $_retry --proto '=https' --tlsv1.2 --ciphers "$_ciphersuites" --silent --show-error --fail --location "$1" --output "$2" 2>&1)
fi
_status=$?
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 $_retry --silent --show-error --fail --location "$1" --output "$2" 2>&1)
_status=$?
else
_err=$(curl $_retry --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, this may be unsupported"
fi
fi
return $_status
elif [ "$_dld" = wget ]; then
if [ "$(wget -V 2>&1|head -2|tail -1|cut -f1 -d" ")" = "BusyBox" ]; then
echo "Warning: using the BusyBox version of wget. Not enforcing strong cipher suites for TLS or TLS v1.2, this is potentially less secure"
_err=$(wget "$1" -O "$2" 2>&1)
_status=$?
else
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
fi
if [ -n "$_err" ]; then
echo "$_err" >&2
if echo "$_err" | grep -q ' 404 Not Found$'; then
err "installer for platform '$3' not found, this may be unsupported"
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
}
# Check if curl supports the --retry flag, then pass it to the curl invocation.
check_curl_for_retry_support() {
local _retry_supported=""
# "unspecified" is for arch, allows for possibility old OS using macports, homebrew, etc.
if check_help_for "notspecified" "curl" "--retry"; then
_retry_supported="--retry 3"
fi
RETVAL="$_retry_supported"
}
# Return cipher suite string specified by user, otherwise return strong TLS 1.2-1.3 cipher suites
# if support by local tools is detected. Detection currently supports these curl backends:
# GnuTLS and OpenSSL (possibly also LibreSSL and BoringSSL). Return value can be empty.
get_ciphersuites_for_curl() {
if [ -n "${RUSTUP_TLS_CIPHERSUITES-}" ]; then
# user specified custom cipher suites, assume they know what they're doing
RETVAL="$RUSTUP_TLS_CIPHERSUITES"
return
fi
local _openssl_syntax="no"
local _gnutls_syntax="no"
local _backend_supported="yes"
if curl -V | grep -q ' OpenSSL/'; then
_openssl_syntax="yes"
elif curl -V | grep -iq ' LibreSSL/'; then
_openssl_syntax="yes"
elif curl -V | grep -iq ' BoringSSL/'; then
_openssl_syntax="yes"
elif curl -V | grep -iq ' GnuTLS/'; then
_gnutls_syntax="yes"
else
_backend_supported="no"
fi
local _args_supported="no"
if [ "$_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 "${RUSTUP_TLS_CIPHERSUITES-}" ]; then
# user specified custom cipher suites, assume they know what they're doing
RETVAL="$RUSTUP_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