(Mono C#) 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 .NET Downloads Chilkat .NET Assemblies Chilkat for .NET Core Chilkat for Mono

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

Chilkat.Crypt2 crypt = new Chilkat.Crypt2();

// Set the MAC algorithm to AES-CMAC
crypt.MacAlgorithm = "aes-cmac";

// AES-CMAC always uses a 16-byte (128-bit) MAC key.
string keyHex = "2b7e151628aed2a6abf7158809cf4f3c";
bool success = crypt.SetMacKeyEncoded(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.
string messageBytes = "6bc1bee22e409f96e93d7e117393172aae2d8a571e03ac9c9eb76fac45af8e5130c81c46a35ce411e5fbc1191a0a52eff69f2445df4f9b17ad2b417be66c3710";

Chilkat.BinData bd = new Chilkat.BinData();
bd.AppendEncoded(messageBytes,"hex");

// Compute the AES-CMAC for the bytes contained in bd and return the AES-CMAC in hex representation.
crypt.EncodingMode = "hex_lower";
string cmac = crypt.MacBdENC(bd);
Debug.WriteLine(cmac);
// Output should be: 51f0bebf7e3b9d92fc49741779363cfe

// Now do the same for a string:
string plainText = "'Twas brillig, and the slithy toves\nDid gyre and gimble in the wabe:\nAll mimsy were the borogoves,\nAnd the mome raths outgrabe.";
string encTag = crypt.MacStringENC(plainText);
Debug.WriteLine(encTag);

// Output should be: 4fca1fcbd265048d247f99ab57fa3ceb