HMAC-SHA256

[danscho1]

Even though the HMAC-SHA1 is still considered secure after the revelation of major flaws in the collision handling in SHA1 itself, it may be appropriate to start supporting the usage of newer algorithms like HMAC-SHA256.
That would be according to the advice to "walk away" from HAMC-SHA1 and to have an answer in case new problems with HMAC-SHA1 occur without having to hastily fix things.