fix(release): repair Apple and Android builds

packaging/android/build-release.sh

@@ -53,18 +53,6 @@ verify_archive_entries() {
 	done
 }
 
-find_apksigner() {
-	if command -v apksigner >/dev/null 2>&1; then
-		command -v apksigner
-		return
-	fi
-	local sdk_root=${ANDROID_SDK_ROOT:-${ANDROID_HOME:-}}
-	[[ -n $sdk_root ]] || return 1
-	find "$sdk_root/build-tools" -type f -name apksigner -perm -111 2>/dev/null |
-		sort -r |
-		head -1
-}
-
 for name in \
 	VNIDROP_ANDROID_KEYSTORE_PATH \
 	VNIDROP_ANDROID_KEYSTORE_PASSWORD \
@@ -119,26 +107,12 @@ grep -F 'jar verified.' <<< "$jarsigner_report" >/dev/null || {
 }
 verify_archive_entries "$source_apk" "${required_apk_libraries[@]}"
 verify_archive_entries "$source_aab" "${required_aab_libraries[@]}"
-apksigner_path="$(find_apksigner)" || {
-	printf 'apksigner was not found in PATH or the Android SDK\n' >&2
-	exit 1
-}
-signature_report="$("$apksigner_path" verify --verbose --print-certs "$source_apk")"
 actual_fingerprint="$(
-	printf '%s\n' "$signature_report" |
-		awk -F': ' '/Signer #1 certificate SHA-256 digest:/ {print $2; exit}'
+	"$script_dir/verify-apk-signature.sh" \
+		"$source_apk" \
+		"$VNIDROP_ANDROID_UPLOAD_CERT_SHA256"
 )"
-[[ -n $actual_fingerprint ]] || {
-	printf 'Could not read the APK signing certificate fingerprint\n' >&2
-	exit 1
-}
-actual_fingerprint="$(normalize_fingerprint "$actual_fingerprint")"
 expected_fingerprint="$(normalize_fingerprint "$VNIDROP_ANDROID_UPLOAD_CERT_SHA256")"
-[[ $actual_fingerprint == "$expected_fingerprint" ]] || {
-	printf 'APK signing certificate mismatch: expected %s, got %s\n' \
-		"$expected_fingerprint" "$actual_fingerprint" >&2
-	exit 1
-}
 aab_fingerprint="$(
 	keytool -printcert -jarfile "$source_aab" |
 		awk -F': ' '/SHA256:/ {print $2; exit}'

packaging/android/tests/test_verify_apk_signature.sh

@@ -0,0 +1,57 @@
+#!/usr/bin/env bash
+
+set -euo pipefail
+
+script_dir="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
+verifier="$script_dir/../verify-apk-signature.sh"
+scratch="$(mktemp -d "${TMPDIR:-/tmp}/vnidrop-apksigner-test.XXXXXX")"
+trap 'rm -rf "$scratch"' EXIT
+
+apk="$scratch/app.apk"
+fake_apksigner="$scratch/apksigner"
+printf 'apk\n' > "$apk"
+
+cat > "$fake_apksigner" <<'SCRIPT'
+#!/usr/bin/env bash
+case "${FAKE_APKSIGNER_MODE:-success}" in
+	success)
+		printf '%s\n' \
+			'Verifies' \
+			'Signer #1 certificate SHA-256 digest: AA:BB:CC:DD' >&2
+		;;
+	missing)
+		printf '%s\n' 'Verifies' >&2
+		;;
+	failure)
+		printf '%s\n' 'invalid APK signature' >&2
+		exit 1
+		;;
+esac
+SCRIPT
+chmod +x "$fake_apksigner"
+
+actual="$(
+	APKSIGNER="$fake_apksigner" \
+		"$verifier" "$apk" "aa bb cc dd"
+)"
+[[ $actual == aabbccdd ]]
+
+if APKSIGNER="$fake_apksigner" \
+	"$verifier" "$apk" deadbeef >/dev/null 2>&1; then
+	printf 'Expected a certificate mismatch to fail\n' >&2
+	exit 1
+fi
+
+if FAKE_APKSIGNER_MODE=missing APKSIGNER="$fake_apksigner" \
+	"$verifier" "$apk" aabbccdd >/dev/null 2>&1; then
+	printf 'Expected missing certificate output to fail\n' >&2
+	exit 1
+fi
+
+if FAKE_APKSIGNER_MODE=failure APKSIGNER="$fake_apksigner" \
+	"$verifier" "$apk" aabbccdd >/dev/null 2>&1; then
+	printf 'Expected signature verification failure to propagate\n' >&2
+	exit 1
+fi
+
+printf 'APK signature verifier tests passed.\n'

packaging/android/verify-apk-signature.sh

@@ -0,0 +1,86 @@
+#!/usr/bin/env bash
+
+set -euo pipefail
+
+if [[ $# -ne 2 ]]; then
+	printf 'Usage: %s <apk> <expected-certificate-sha256>\n' "$0" >&2
+	exit 2
+fi
+
+apk=$1
+expected_fingerprint=$2
+build_tools_version=${ANDROID_BUILD_TOOLS_VERSION:-36.0.0}
+
+normalize_fingerprint() {
+	printf '%s' "$1" |
+		tr -d '[:space:]:' |
+		tr '[:upper:]' '[:lower:]'
+}
+
+find_apksigner() {
+	if [[ -n ${APKSIGNER:-} ]]; then
+		[[ -x $APKSIGNER ]] || {
+			printf 'Configured apksigner is not executable: %s\n' "$APKSIGNER" >&2
+			return 1
+		}
+		printf '%s\n' "$APKSIGNER"
+		return
+	fi
+
+	local sdk_root=${ANDROID_SDK_ROOT:-${ANDROID_HOME:-}}
+	if [[ -n $sdk_root ]]; then
+		local pinned="$sdk_root/build-tools/$build_tools_version/apksigner"
+		if [[ -x $pinned ]]; then
+			printf '%s\n' "$pinned"
+			return
+		fi
+	fi
+
+	if command -v apksigner >/dev/null 2>&1; then
+		command -v apksigner
+		return
+	fi
+
+	printf 'apksigner %s was not found in the Android SDK or PATH\n' \
+		"$build_tools_version" >&2
+	return 1
+}
+
+[[ -s $apk ]] || {
+	printf 'APK is missing or empty: %s\n' "$apk" >&2
+	exit 1
+}
+
+apksigner_path="$(find_apksigner)" || exit 1
+if ! signature_report="$(
+	"$apksigner_path" verify --verbose --print-certs "$apk" 2>&1
+)"; then
+	printf 'APK signature verification failed:\n%s\n' "$signature_report" >&2
+	exit 1
+fi
+
+actual_fingerprint="$(
+	printf '%s\n' "$signature_report" |
+		awk '
+			tolower($0) ~ /^signer #1 certificate sha-256 digest:[[:space:]]*/ {
+				line = $0
+				sub(/^[^:]*:[[:space:]]*/, "", line)
+				print line
+				exit
+			}
+		'
+)"
+[[ -n $actual_fingerprint ]] || {
+	printf 'Could not read the APK signing certificate fingerprint\n' >&2
+	exit 1
+}
+
+actual_fingerprint="$(normalize_fingerprint "$actual_fingerprint")"
+expected_fingerprint="$(normalize_fingerprint "$expected_fingerprint")"
+[[ $actual_fingerprint == "$expected_fingerprint" ]] || {
+	printf 'APK signing certificate mismatch: expected %s, got %s\n' \
+		"$expected_fingerprint" "$actual_fingerprint" >&2
+	exit 1
+}
+
+printf '%s\n' "$actual_fingerprint"