[erlang-questions] How to use crypto:hmac_init() and friends?
Thu Nov 19 14:37:32 CET 2015
I have to create the HMAC of a message by including data at several
points in my code as shown below:
Mac_ctxt_init = crypto:hmac_init(sha256, Mac_key),
Mac_ctxt = case Version of
Mac_ctxt1 = crypto:hmac_update(Mac_ctxt_init, Dhi_pub),
LMac_ctxt = crypto:hmac_update(Mac_ctxt, <<Version/binary,
LMac = crypto:hmac_final_n(LMac_ctxt, 8),
This will always return <<>>! It already starts with the hmac_init()
which returns <<>>.
Erlang/OTP 18 [erts-7.1] [source] [64-bit] [smp:2:2] [async-threads:10]
Eshell V7.1 (abort with ^G)
1> K =
2> crypto:hmac_init(sha256, K).
Using crypto:hmac(sha256, K, Data, 8) works fine, but is not usable.
Any idea what goes wrong or what I am doing wrong?
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