PMK derivation in Host AP
Manoj Verma, Noida
manojv at noida.hcltech.com
Mon Sep 6 15:46:56 EDT 2004
I was trying to find out the exact place in the Host-AP code for the
derivation of PMK (256 bit) from the master secret key.
I found that:
In function eap_ttls_process (), the master secret is passed as a parameter
to eap_tls_derive_key(), which internally user eap_prf() function, to get
the another key.
My confusion is, the key above obtained is of length EAP_TLS_KEY_LEN i.e.
64, then where exactly the 256 bit PMK is derived in the code.
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