Visual FoxPro

Poly1305 MAC

See more Encryption Examples

Demonstrates the Poly1305 Message Authentication Code. (Introduced in Chilkat v9.5.0.55) This example duplicates the results of Test Vector #4 for Poly1305 in RFC 7539. Visual FoxPro

LOCAL lnSuccess
LOCAL loCrypt
LOCAL lcKeyHex
LOCAL lcPlainText
LOCAL lcEncTag

lnSuccess = 0

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

loCrypt = CreateObject('Chilkat.Crypt2')

*  Set the MAC algorithm to poly1305
loCrypt.MacAlgorithm = "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".
loCrypt.EncodingMode = "hex"

*  Poly1305 always uses a 32-byte (256-bit) MAC key.
lcKeyHex = "1c9240a5eb55d38af333888604f6b5f0473917c1402b80099dca5cbc207075c0"
lnSuccess = loCrypt.SetMacKeyEncoded(lcKeyHex,"hex")

lcPlainText = "'Twas brillig, and the slithy toves" + CHR(10) + "Did gyre and gimble in the wabe:" + CHR(10) + "All mimsy were the borogoves," + CHR(10) + "And the mome raths outgrabe."

*  The computed tag should match the Tag shown below.
*  (Note: hexidecimal encoding is case insensitive.)
lcEncTag = loCrypt.MacStringENC(lcPlainText)
? lcEncTag

*  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

RELEASE loCrypt