It was possible for some NFC DH generation error paths to leak memory
since the old private/public key was not freed if an allocation failed.
Signed-off-by: Jouni Malinen <j@w1.fi>
Crypto library wrappers can now override the internal DH (group 5)
implementation. As a starting point, this is done with OpenSSL. The
new mechanism is currently available only for WPS (i.e., IKEv2 still
depends on the internal DH implementation).