(Tcl) HMAC Hex String

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

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load ./chilkat.dll

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

set crypt [new_CkCrypt2]

# Set the MAC algorithm to HMAC
CkCrypt2_put_MacAlgorithm $crypt "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', ...)
set keyHex "41C21CB9D7A02FC5D4FADB9E4755B9DE"
set success [CkCrypt2_SetMacKeyEncoded $crypt $keyHex "hex"]

# Our desire is to HMAC the bytes represented in the following string:
set dataHex "C22078065B01460001000000010062043BF5B18228C8E02D17BCFE4E00561FA6DEC216EA97195CEB579942E275C21932258E3CD391E507FF4E7FD4C787A8447DA111C54A9C1795E7FF4C0BAA2EDA"

# We'll need to decode the hex to binary:
set bd [new_CkBinData]

CkBinData_AppendEncoded $bd $dataHex "hex"

# Do the HMAC-SHA256 hash and return as a hex string:
CkCrypt2_put_EncodingMode $crypt "hex"
CkCrypt2_put_HashAlgorithm $crypt "sha-256"
set macHex [CkCrypt2_macBdENC $crypt $bd]
puts "$macHex"

delete_CkCrypt2 $crypt
delete_CkBinData $bd