(PureBasic) 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 PureBasic Module Download Chilkat PureBasic Module

IncludeFile "CkCrypt2.pb"
IncludeFile "CkBinData.pb"

Procedure ChilkatExample()

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

    crypt.i = CkCrypt2::ckCreate()
    If crypt.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    ; Set the MAC algorithm to AES-CMAC
    CkCrypt2::setCkMacAlgorithm(crypt, "aes-cmac")

    ; AES-CMAC always uses a 16-byte (128-bit) MAC key.
    keyHex.s = "2b7e151628aed2a6abf7158809cf4f3c"
    success.i = CkCrypt2::ckSetMacKeyEncoded(crypt,keyHex,"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.
    messageBytes.s = "6bc1bee22e409f96e93d7e117393172aae2d8a571e03ac9c9eb76fac45af8e5130c81c46a35ce411e5fbc1191a0a52eff69f2445df4f9b17ad2b417be66c3710"

    bd.i = CkBinData::ckCreate()
    If bd.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    CkBinData::ckAppendEncoded(bd,messageBytes,"hex")

    ; Compute the AES-CMAC for the bytes contained in bd and return the AES-CMAC in hex representation.
    CkCrypt2::setCkEncodingMode(crypt, "hex_lower")
    cmac.s = CkCrypt2::ckMacBdENC(crypt,bd)
    Debug cmac
    ; Output should be: 51f0bebf7e3b9d92fc49741779363cfe

    ; Now do the same for a string:
    plainText.s = "'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."
    encTag.s = CkCrypt2::ckMacStringENC(crypt,plainText)
    Debug encTag

    ; Output should be: 4fca1fcbd265048d247f99ab57fa3ceb


    CkCrypt2::ckDispose(crypt)
    CkBinData::ckDispose(bd)


    ProcedureReturn
EndProcedure