Lua Requires Chilkat v9.5.0.55+

Poly1305 MAC

See more Encryption Examples

Demonstrates the Poly1305 Message Authentication Code. This example duplicates the results of Test Vector #4 for Poly1305 in RFC 7539. Lua

local chilkat = require("chilkat")

-- This example assumes the Chilkat API to have been previously unlocked.
-- See Global Unlock Sample for sample code.

local crypt = chilkat.Crypt2.new()

-- Set the MAC algorithm to poly1305
crypt.mac_algorithm = "poly1305"

-- EncodingMode specifies the encoding of the output for
-- encryption, and the input for decryption.
-- Valid modes are (case insensitive) "Base64", "modBase64", "Base32", "Base58", "UU",
-- "QP" (for quoted-printable), "URL" (for url-encoding), "Hex",
-- "Q", "B", "url_oauth", "url_rfc1738", "url_rfc2396", and "url_rfc3986".
crypt.encoding_mode = "hex"

-- Poly1305 always uses a 32-byte (256-bit) MAC key.
local keyHex = "1c9240a5eb55d38af333888604f6b5f0473917c1402b80099dca5cbc207075c0"
local success = crypt:set_mac_key_encoded(keyHex, "hex")

local plainText = "'Twas brillig, and the slithy toves\nDid gyre and gimble in the wabe:\nAll mimsy were the borogoves,\nAnd the mome raths outgrabe."

-- The computed tag should match the Tag shown below.
-- (Note: hexidecimal encoding is case insensitive.)
local encTag = crypt:mac_string_enc(plainText)
print(encTag)

-- Here is the Test Vector data copied from RFC 7539

--  Test Vector #4:
--  ==============
--
--  One-time Poly1305 Key:
--  000  1c 92 40 a5 eb 55 d3 8a f3 33 88 86 04 f6 b5 f0  ..@..U...3......
--  016  47 39 17 c1 40 2b 80 09 9d ca 5c bc 20 70 75 c0  G9..@+....\. pu.
--
--  Text to MAC:
--  000  27 54 77 61 73 20 62 72 69 6c 6c 69 67 2c 20 61  'Twas brillig, a
--  016  6e 64 20 74 68 65 20 73 6c 69 74 68 79 20 74 6f  nd the slithy to
--  032  76 65 73 0a 44 69 64 20 67 79 72 65 20 61 6e 64  ves.Did gyre and
--  048  20 67 69 6d 62 6c 65 20 69 6e 20 74 68 65 20 77   gimble in the w
--  064  61 62 65 3a 0a 41 6c 6c 20 6d 69 6d 73 79 20 77  abe:.All mimsy w
--  080  65 72 65 20 74 68 65 20 62 6f 72 6f 67 6f 76 65  ere the borogove
--  096  73 2c 0a 41 6e 64 20 74 68 65 20 6d 6f 6d 65 20  s,.And the mome
--  112  72 61 74 68 73 20 6f 75 74 67 72 61 62 65 2e     raths outgrabe.
--
--  Tag:
--  000  45 41 66 9a 7e aa ee 61 e7 08 dc 7c bc c5 eb 62  EAf.~..a...|...b