Formatting of lua programs (two space indentation), also feature based check in gpg.lua which is more in line with other components.

src/main/resources/assets/opencomputers/lua/component/data/bin/gpg.lua

@@ -13,8 +13,8 @@ local args, options = shell.parse(...)
 
 local function writeFile(path, data)
   if filesystem.exists(path) then
-        print("gpg: failed to write file: " .. path)
+    io.stderr:write("gpg: failed to write file: " .. path .. "\n")
-        print("gpg: error was: file already exists")
+    io.stderr:write("gpg: error was: file already exists\n")
     return false
   end
 
@@ -25,8 +25,8 @@ local function writeFile(path, data)
   local h, err = io.open(path, "wb")
 
   if not h then
-        print("gpg: failed to write file: " .. path)
+    io.stderr:write("gpg: failed to write file: " .. path .. "\n")
-        print("gpg: error was: " .. err)
+    io.stderr:write("gpg: error was: " .. err .. "\n")
     return false
   end
 
@@ -52,12 +52,12 @@ local function parseKey(path, isPublic)
   local k, err = data.deserializeKey(d.d, d.t)
 
   if not k then
-        print("gpg: failed to parse key: " .. err)
+    io.stderr:write("gpg: failed to parse key: " .. err .. "\n")
     return nil
   end
 
   if k.isPublic() ~= isPublic then
-        print("gpg: wrong key type")
+    io.stderr:write("gpg: wrong key type\n")
     return nil
   end
 
@@ -71,38 +71,41 @@ local function deriveName(base, encrypt)
     local d = base:gsub(".gpg", "")
     if d == base then
       d = d .. ".dec"
-            print("gpg: decrypting to " .. d)
+      io.write("gpg: decrypting to " .. d .. "\n")
     end
     return d
   end
 end
 
-local function ensureTier(tier)
+local function ensureMethods(...)
   if not require("component").isAvailable("data") then
-        print("gpg: you must have data card in order to run this program")
+    io.stderr:write("gpg: you must have data card in order to run this program\n")
     error("data card is absent")
   end
 
-    if data.tier() < tier then
+  local names = table.pack(...)
-        print("gpg: you must have tier " .. tier .. " data card in order to run this program")
+  for i = 1, names.n do
-        error("data card is too simple")
+    if names[i] and not data[names[i]] then
+      io.stderr:write("gpg: method " .. names[i] .. " required on data card to run this program\n")
+      error("data card tier insufficient")
+    end
   end
 end
 
 if options['g'] and (#args == 2) then
-    ensureTier(3)
+  ensureMethods("generateKeyPair")
   local pub, priv = data.generateKeyPair(384)
 
   priv = { t = priv.keyType(), d = priv.serialize() }
   pub = { t = pub.keyType(), d = pub.serialize() }
 
   if not writeFile(args[1], priv) then
-        print("gpg: failed to write private key, aborting")
+    io.stderr:write("gpg: failed to write private key, aborting\n")
     return false
   end
 
   if not writeFile(args[2], pub) then
-        print("gpg: failed to write public key, aborting")
+    io.stderr:write("gpg: failed to write public key, aborting\n")
     return false
   end
 
@@ -110,9 +113,9 @@ if options['g'] and (#args == 2) then
 end
 
 if options['c'] and (options['e'] or options['d']) and (#args == 1) then
-    ensureTier(2)
+  ensureMethods("md5", "sha256", "encrypt", "decrypt", "random")
   if options['d'] and options['e'] then
-        print("gpg: please specify either -d or -e")
+    io.stderr:write("gpg: please specify either -d or -e\n")
     return false
   end
 
@@ -135,12 +138,12 @@ if options['c'] and (options['e'] or options['d']) and (#args == 1) then
     local d = readFile(args[1], true)
 
     if d.t ~= "pwd" then
-            print("gpg: file is not encrypted with a password")
+      io.stderr:write("gpg: file is not encrypted with a password\n")
       return false
     end
 
     if checkValue ~= d.cv then
-            print("gpg: password incorrect")
+      io.stderr:write("gpg: password incorrect\n")
       return false
     end
 
@@ -149,9 +152,9 @@ if options['c'] and (options['e'] or options['d']) and (#args == 1) then
 end
 
 if (options['d'] or options['e']) and (#args == 2) then
-    ensureTier(3)
+  ensureMethods("md5", "sha256", "encrypt", "decrypt", "random", "generateKeyPair", "deserializeKey", "ecdh")
   if options['d'] and options['e'] then
-        print("gpg: please specify either -d or -e")
+    io.stderr:write("gpg: please specify either -d or -e\n")
     return false
   end
 
@@ -179,7 +182,7 @@ if (options['d'] or options['e']) and (#args == 2) then
     local d = readFile(args[2], true)
 
     if d.t ~= "ecdh" then
-            print("gpg: file is not encrypted with a key")
+      io.stderr:write("gpg: file is not encrypted with a key\n")
       return false
     end
 
@@ -187,7 +190,7 @@ if (options['d'] or options['e']) and (#args == 2) then
     local aesKey = data.md5(data.ecdh(userPriv, tmpPub))
 
     if d.cv ~= data.sha256(aesKey) then
-            print("gpg: invalid key")
+      io.stderr:write("gpg: invalid key\n")
       return false
     end
 
@@ -196,9 +199,9 @@ if (options['d'] or options['e']) and (#args == 2) then
 end
 
 if (options['s'] or options['v']) and (#args == 2) then
-    ensureTier(2)
+  ensureMethods("deserializeKey", "ecdsa")
   if options['s'] and options['v'] then
-        print("gpg: please specify either -s or -v")
+    io.stderr:write("gpg: please specify either -s or -v\n")
     return false
   end
 
@@ -215,16 +218,16 @@ if (options['s'] or options['v']) and (#args == 2) then
     local sign = readFile(args[2] .. ".sig", true)
 
     if sign.t ~= "ecdsa" then
-            print("gpg: unsupported signature type")
+      io.stderr:write("gpg: unsupported signature type\n")
       return false
     end
 
     if not data.ecdsa(readFile(args[2]), userPub, sign.s) then
-            print("gpg: signature verification failed")
+      io.stderr:write("gpg: signature verification failed\n")
       return false
     end
 
-        print("gpg: signature is valid")
+    io.write("gpg: signature is valid\n")
 
     return true
   end

src/main/resources/assets/opencomputers/lua/component/data/lib/data.lua

@@ -26,7 +26,7 @@ if component.isAvailable("data") then
     return true
   end
 
-    for i, v in ipairs(wrappedFunctions) do
+  for _, v in ipairs(wrappedFunctions) do
     data[v] = component.data[v]
   end
 else