Reformat + add prefix selection for config

src/lib/plc/aead_chacha_poly.lua

@@ -23,67 +23,67 @@ local poly1305 = require "lib.plc.poly1305"
 -- poly1305 key generation
 
 local poly_keygen = function(key, nonce)
-	local counter = 0
-	local m = string.rep('\0', 64)
-	local e = chacha20.encrypt(key, counter, nonce, m)
-	-- keep only first the 256 bits (32 bytes)
-	return e:sub(1, 32)
+  local counter = 0
+  local m = string.rep('\0', 64)
+  local e = chacha20.encrypt(key, counter, nonce, m)
+  -- keep only first the 256 bits (32 bytes)
+  return e:sub(1, 32)
 end
 
 local pad16 = function(s)
-	-- return null bytes to add to s so that #s is a multiple of 16
-	return (#s % 16 == 0) and "" or ('\0'):rep(16 - (#s % 16))
+  -- return null bytes to add to s so that #s is a multiple of 16
+  return (#s % 16 == 0) and "" or ('\0'):rep(16 - (#s % 16))
 end
 
 local app = table.insert
 
 local encrypt = function(aad, key, iv, constant, plain)
-	-- aad: additional authenticated data - arbitrary length
-	-- key: 32-byte string
-	-- iv, constant: concatenated to form the nonce (12 bytes)
-	--   (why not one 12-byte param? --maybe because IPsec uses
-	--   an 8-byte nonce)
-	-- implementation: RFC 7539 sect 2.8.1
-	-- (memory inefficient - encr text is copied in mac_data)
-	local mt = {} -- mac_data table
-	local nonce = constant .. iv
-	local otk = poly_keygen(key, nonce)
-	local encr = chacha20.encrypt(key, 1, nonce, plain)
-	app(mt, aad)
-	app(mt, pad16(aad))
-	app(mt, encr)
-	app(mt, pad16(encr))
-	-- aad and encrypted text length must be encoded as
-	-- little endian _u64_ (and not u32) -- see errata at
-	-- https://www.rfc-editor.org/errata_search.php?rfc=7539
-	app(mt, string.pack('<I8', #aad))
-	app(mt, string.pack('<I8', #encr))
-	local mac_data = table.concat(mt)
---~ 	p16('mac', mac_data)
-	local tag = poly1305.auth(mac_data, otk)
-	return encr, tag
+  -- aad: additional authenticated data - arbitrary length
+  -- key: 32-byte string
+  -- iv, constant: concatenated to form the nonce (12 bytes)
+  --   (why not one 12-byte param? --maybe because IPsec uses
+  --   an 8-byte nonce)
+  -- implementation: RFC 7539 sect 2.8.1
+  -- (memory inefficient - encr text is copied in mac_data)
+  local mt = {} -- mac_data table
+  local nonce = constant .. iv
+  local otk = poly_keygen(key, nonce)
+  local encr = chacha20.encrypt(key, 1, nonce, plain)
+  app(mt, aad)
+  app(mt, pad16(aad))
+  app(mt, encr)
+  app(mt, pad16(encr))
+  -- aad and encrypted text length must be encoded as
+  -- little endian _u64_ (and not u32) -- see errata at
+  -- https://www.rfc-editor.org/errata_search.php?rfc=7539
+  app(mt, string.pack('<I8', #aad))
+  app(mt, string.pack('<I8', #encr))
+  local mac_data = table.concat(mt)
+  --~ 	p16('mac', mac_data)
+  local tag = poly1305.auth(mac_data, otk)
+  return encr, tag
 end --chacha20_aead_encrypt()
 
 local function decrypt(aad, key, iv, constant, encr, tag)
-	-- (memory inefficient - encr text is copied in mac_data)
-	-- (structure similar to aead_encrypt => what could be factored?)
-	local mt = {} -- mac_data table
-	local nonce = constant .. iv
-	local otk = poly_keygen(key, nonce)
-	app(mt, aad)
-	app(mt, pad16(aad))
-	app(mt, encr)
-	app(mt, pad16(encr))
-	app(mt, string.pack('<I8', #aad))
-	app(mt, string.pack('<I8', #encr))
-	local mac_data = table.concat(mt)
-	local mac = poly1305.auth(mac_data, otk)
-	if mac == tag then
-		local plain = chacha20.encrypt(key, 1, nonce, encr)
-		return plain
-	else
-		return nil, "auth failed"
-	end
+  -- (memory inefficient - encr text is copied in mac_data)
+  -- (structure similar to aead_encrypt => what could be factored?)
+  local mt = {} -- mac_data table
+  local nonce = constant .. iv
+  local otk = poly_keygen(key, nonce)
+  app(mt, aad)
+  app(mt, pad16(aad))
+  app(mt, encr)
+  app(mt, pad16(encr))
+  app(mt, string.pack('<I8', #aad))
+  app(mt, string.pack('<I8', #encr))
+  local mac_data = table.concat(mt)
+  local mac = poly1305.auth(mac_data, otk)
+  if mac == tag then
+    local plain = chacha20.encrypt(key, 1, nonce, encr)
+    return plain
+  else
+    return nil, "auth failed"
+  end
 end --chacha20_aead_decrypt()
 
 
@@ -91,7 +91,7 @@ end --chacha20_aead_decrypt()
 -- return aead_chacha_poly module
 
 return {
-	poly_keygen = poly_keygen,
-	encrypt = encrypt,
-	decrypt = decrypt,
-	}
+  poly_keygen = poly_keygen,
+  encrypt = encrypt,
+  decrypt = decrypt,
+}