(Visual FoxPro) AES-CMAC

Demonstrates using the AES-CMAC algorithm, which is a keyed hash function similar to HMAC and Poly1305.

Note: Chilkat added AES-CMAC in version 9.5.0.95.

Chilkat ActiveX Downloads ActiveX for 32-bit and 64-bit Windows

LOCAL loCrypt
LOCAL lcKeyHex
LOCAL lnSuccess
LOCAL lcMessageBytes
LOCAL loBd
LOCAL lcCmac
LOCAL lcPlainText
LOCAL lcEncTag

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

* For versions of Chilkat < 10.0.0, use CreateObject('Chilkat_9_5_0.Crypt2')
loCrypt = CreateObject('Chilkat.Crypt2')

* Set the MAC algorithm to AES-CMAC
loCrypt.MacAlgorithm = "aes-cmac"

* AES-CMAC always uses a 16-byte (128-bit) MAC key.
lcKeyHex = "2b7e151628aed2a6abf7158809cf4f3c"
lnSuccess = loCrypt.SetMacKeyEncoded(lcKeyHex,"hex")

* Let's compute the AES-CMAC for the test vector at https://www.rfc-editor.org/rfc/rfc4493#appendix-A
* Here we have 64 bytes in hex representation.
lcMessageBytes = "6bc1bee22e409f96e93d7e117393172aae2d8a571e03ac9c9eb76fac45af8e5130c81c46a35ce411e5fbc1191a0a52eff69f2445df4f9b17ad2b417be66c3710"

* For versions of Chilkat < 10.0.0, use CreateObject('Chilkat_9_5_0.BinData')
loBd = CreateObject('Chilkat.BinData')
loBd.AppendEncoded(lcMessageBytes,"hex")

* Compute the AES-CMAC for the bytes contained in bd and return the AES-CMAC in hex representation.
loCrypt.EncodingMode = "hex_lower"
lcCmac = loCrypt.MacBdENC(loBd)
? lcCmac
* Output should be: 51f0bebf7e3b9d92fc49741779363cfe

* Now do the same for a string:
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."
lcEncTag = loCrypt.MacStringENC(lcPlainText)
? lcEncTag

* Output should be: 4fca1fcbd265048d247f99ab57fa3ceb

RELEASE loCrypt
RELEASE loBd