From 64218c9a5cb414b50e71a61cc1246f2b2705ed22 Mon Sep 17 00:00:00 2001
From: oddlama <oddlama@oddlama.org>
Date: Sat, 14 May 2022 00:28:52 +0200
Subject: [PATCH] feat: fallback to sha512sum if rhash is not available. closes
 #36.

---
 configure            |  2 +-
 scripts/functions.sh | 26 +++++++++++++++---------
 scripts/utils.sh     | 48 +++++++++++++++++++++++++++++++++-----------
 3 files changed, 54 insertions(+), 22 deletions(-)

diff --git a/configure b/configure
index 6d4eab0..44745db 100755
--- a/configure
+++ b/configure
@@ -44,7 +44,7 @@ while [[ $# -gt 0 ]]; do
 	shift
 done
 
-check_has_programs dialog ncurses=ncursesw6-config
+check_wanted_programs dialog ncurses=ncursesw6-config
 
 # Determine whether EFI is available
 HAS_EFI_SUPPORT=$([[ -d /sys/firmware/efi ]] && echo -n "true" || echo -n "false")
diff --git a/scripts/functions.sh b/scripts/functions.sh
index 42ed4d2..5d4c065 100644
--- a/scripts/functions.sh
+++ b/scripts/functions.sh
@@ -66,30 +66,31 @@ function preprocess_config() {
 function prepare_installation_environment() {
 	einfo "Preparing installation environment"
 
-	local needed_programs=(
+	local wanted_programs=(
 		gpg
 		hwclock
 		lsblk
 		ntpd
 		partprobe
 		python3
-		rhash
+		?rhash
+		sha512sum
 		sgdisk
 		uuidgen
 		wget
 	)
 
 	[[ $USED_BTRFS == "true" ]] \
-		&& needed_programs+=(btrfs)
+		&& wanted_programs+=(btrfs)
 	[[ $USED_ZFS == "true" ]] \
-		&& needed_programs+=(zfs)
+		&& wanted_programs+=(zfs)
 	[[ $USED_RAID == "true" ]] \
-		&& needed_programs+=(mdadm)
+		&& wanted_programs+=(mdadm)
 	[[ $USED_LUKS == "true" ]] \
-		&& needed_programs+=(cryptsetup)
+		&& wanted_programs+=(cryptsetup)
 
 	# Check for existence of required programs
-	check_has_programs "${needed_programs[@]}"
+	check_wanted_programs "${wanted_programs[@]}"
 
 	# Sync time now to prevent issues later
 	sync_time
@@ -790,6 +791,7 @@ function download_stage3() {
 		|| die "Could not cd into '$TMP_DIR'"
 
 	local STAGE3_RELEASES="$GENTOO_MIRROR/releases/amd64/autobuilds/current-$STAGE3_BASENAME/"
+	local sha512sums
 
 	# Download upstream list of files
 	CURRENT_STAGE3="$(download_stdout "$STAGE3_RELEASES")" \
@@ -829,8 +831,14 @@ function download_stage3() {
 		# Check hashes
 		einfo "Verifying tarball integrity"
 		# Replace any absolute paths in the digest file with just the stage3 basename, so it will be found by rhash
-		rhash -P --check <(grep -B 1 'tar.xz$' "${CURRENT_STAGE3}.DIGESTS" | sed -e 's/  .*stage3-/  stage3-/') \
-			|| die "Checksum mismatch!"
+		digest_line=$(grep 'tar.xz$' "${CURRENT_STAGE3}.DIGESTS" | sed -e 's/  .*stage3-/  stage3-/')
+		if type "$program" &>/dev/null; then
+			rhash -P --check <(echo "# SHA512"; echo "$digest_line") \
+				|| die "Checksum mismatch!"
+		else
+			sha512sum --check <<< "$digest_line" \
+				|| die "Checksum mismatch!"
+		fi
 
 		# Create verification file in case the script is restarted
 		touch_or_die 0644 "$CURRENT_STAGE3_VERIFIED"
diff --git a/scripts/utils.sh b/scripts/utils.sh
index a5908d5..b3ddca9 100644
--- a/scripts/utils.sh
+++ b/scripts/utils.sh
@@ -351,31 +351,51 @@ function parse_arguments() {
 	fi
 }
 
-function check_has_programs() {
-	local failed=()
+# $1: array
+# $@: elements
+function append_to_array() {
+	declare -n _target_array=$1; shift
+	_target_array+=("$@")
+}
+
+function check_wanted_programs() {
+	local missing_required=()
+	local missing_wanted=()
 	local tuple
 	local program
 	local checkfile
 	for tuple in "$@"; do
 		program="${tuple%%=*}"
 		checkfile="${tuple##*=}"
+		if [[ "$program" == "?"* ]]; then
+			program="${program#"?"}"
+			arr=missing_wanted
+		else
+			arr=missing_required
+		fi
 		if [[ -z "$checkfile" ]]; then
 			type "$program" &>/dev/null \
-				|| failed+=("$program")
+				|| append_to_array "$arr" "$program"
 		elif [[ "${checkfile:0:1}" == "/" ]]; then
 			[[ -e "$checkfile" ]] \
-				|| failed+=("$program")
+				|| append_to_array "$arr" "$program"
 		else
 			type "$checkfile" &>/dev/null \
-				|| failed+=("$program")
+				|| append_to_array "$arr" "$program"
 		fi
 	done
 
-	[[ "${#failed[@]}" -eq 0 ]] \
+	[[ "${#missing_required[@]}" -eq 0 && "${#missing_required[@]}" -eq 0 ]] \
 		&& return
 
-	elog "The following programs are required for the installer to work, but are currently missing on your system:" >&2
-	elog "  ${failed[*]}" >&2
+	if [[ "${#missing_required[@]}" -gt 0 ]]; then
+		elog "The following programs are required for the installer to work, but are currently missing on your system:" >&2
+		elog "  ${missing_required[*]}" >&2
+	fi
+	if [[ "${#missing_wanted[@]}" -gt 0 ]]; then
+		elog "Missing optional programs:" >&2
+		elog "  ${missing_wanted[*]}" >&2
+	fi
 
 	if type pacman &>/dev/null; then
 		declare -A pacman_packages
@@ -383,12 +403,12 @@ function check_has_programs() {
 			[ntpd]=ntp
 			[zfs]=""
 		)
-		elog "We have detected that pacman is available."
-		if ask "Do you want to install the missing programs automatically?"; then
+		elog "Detected pacman package manager."
+		if ask "Do you want to install all missing programs automatically?"; then
 			local packages
 			local need_zfs=false
 
-			for program in "${failed[@]}"; do
+			for program in "${missing_required[@]}" "${missing_wanted[@]}"; do
 				[[ "$program" == "zfs" ]] \
 					&& need_zfs=true
 
@@ -415,5 +435,9 @@ function check_has_programs() {
 		fi
 	fi
 
-	die "Aborted installer because of missing required programs."
+	if [[ "${#missing_required[@]}" -gt 0 ]]; then
+		die "Aborted installer because of missing required programs."
+	else
+		ask "Continue without recommended programs?"
+	fi
 }