HMAC Hash Message Authentication Code Function

HMAC takes three inputs (key, message, hash method) and outputs hash message authentication code

HMAC(key,message,method)

INPUT
key: input secret key in char
message: input message in char
method: hash method, either:
'SHA-1', 'SHA-256', 'SHA-384', 'SHA-512'

OUTPUT
HMAC: Hash message authentication code value in upper case HEX.

You must download the DataHash.m function made by Jan Simon in order to use HMAC.m. It can be found here:

http://www.mathworks.com/matlabcentral/fileexchange/31272-datahash

If needed, you can verify your output here:

http://www.freeformatter.com/hmac-generator.html#ad-output

More information on HMAC here:

http://en.wikipedia.org/wiki/Hash-based_message_authentication_code