Introduce reproducible, prebuilt binaries

Makefile

@@ -0,0 +1,36 @@
+# (Default) build the Recovery Tool to run on this system.
+build:
+	mkdir -p bin
+	
+	echo "Building recovery tool"
+	go build -a -trimpath -o "bin/recovery-tool"
+
+	echo "Success! Built to bin/recovery-tool"
+
+# Cross-compile and checksum the Recovery Tool for a range of OS/archs.
+build-checksum-all: export DOCKER_BUILDKIT=1
+build-checksum-all:
+	# Get vendor dependencies:
+	go mod vendor -v
+
+	# Linux 32-bit:
+	docker build . -o bin --build-arg os=linux --build-arg arch=386 --build-arg out=recovery-tool-linux32
+	/bin/echo -n '✓ Linux 32-bit ' && sha256sum "bin/recovery-tool-linux32"
+
+	# Linux 64-bit:
+	docker build . -o bin --build-arg os=linux --build-arg arch=amd64 --build-arg out=recovery-tool-linux64
+	/bin/echo -n '✓ Linux 64-bit ' && sha256sum "bin/recovery-tool-linux64"
+	
+	# Windows 32-bit:
+	docker build . -o bin --build-arg os=windows --build-arg arch=386 --build-arg out=recovery-tool-windows32.exe
+	/bin/echo -n '✓ Windows 32-bit ' && sha256sum "bin/recovery-tool-windows32.exe"
+	
+	# Windows 64-bit:
+	docker build . -o bin --build-arg os=windows --build-arg arch=amd64 --build-arg out=recovery-tool-windows64.exe
+	/bin/echo -n '✓ Windows 64-bit ' && sha256sum "bin/recovery-tool-windows64.exe"
+
+	# Darwin 64-bit:
+	docker build . -o bin --build-arg os=darwin --build-arg arch=amd64 --build-arg out=recovery-tool-macos64
+	/bin/echo -n '✓ MacOS 64-bit ' && sha256sum "bin/recovery-tool-macos64"
+
+.SILENT: