(Visual FoxPro) HMAC Hex String

Demonstrates how to compute an HMAC using a hexidecimal key and data.

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

LOCAL loCrypt
LOCAL lcKeyHex
LOCAL lnSuccess
LOCAL lcDataHex
LOCAL loBd
LOCAL lcMacHex

* 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 HMAC
loCrypt.MacAlgorithm = "hmac"

* Our HMAC key will be the bytes represented in the following hex string.
* In other words, the HMAC key is composed of the bytes 0x41, 0xC2, 0x1C, ...
* (It is not composed of the us-ascii string '4', '1', 'C', ...)
lcKeyHex = "41C21CB9D7A02FC5D4FADB9E4755B9DE"
lnSuccess = loCrypt.SetMacKeyEncoded(lcKeyHex,"hex")

* Our desire is to HMAC the bytes represented in the following string:
lcDataHex = "C22078065B01460001000000010062043BF5B18228C8E02D17BCFE4E00561FA6DEC216EA97195CEB579942E275C21932258E3CD391E507FF4E7FD4C787A8447DA111C54A9C1795E7FF4C0BAA2EDA"

* We'll need to decode the hex to binary:
* For versions of Chilkat < 10.0.0, use CreateObject('Chilkat_9_5_0.BinData')
loBd = CreateObject('Chilkat.BinData')
loBd.AppendEncoded(lcDataHex,"hex")

* Do the HMAC-SHA256 hash and return as a hex string:
loCrypt.EncodingMode = "hex"
loCrypt.HashAlgorithm = "sha-256"
lcMacHex = loCrypt.MacBdENC(loBd)
? lcMacHex

RELEASE loCrypt
RELEASE loBd