1 files changed, 28 insertions, 0 deletions
diff --git a/scripts/granger/util.lua b/scripts/granger/util.lua
new file mode 100644
index 0000000..77dc476
--- /dev/null
+++ b/scripts/granger/util.lua
@@ -0,0 +1,28 @@
+--
+-- util.lua
+-- various utility functions
+-- Copyright (c) 2016 Jeff Kent <jeff@jkent.net>
+--
+
+local function hash_file(file, ctx)
+	local f = io.open(file, "r")
+	if f == nil then
+		return nil
+	end
+	repeat
+		local buf = f:read(0x10000)
+		ctx:update(buf)
+	until buf == nil
+	f:close()
+	return tostring(ctx)
+end
+
+function sha256_file(file)
+	local ctx = nettle.sha256()
+	return hash_file(file, ctx)
+end
+
+function md5_file(file)
+	local ctx = nettle.md5()
+	return hash_file(file, ctx)
+end