Move the basic processing of received frames into eap_tls_common.c and use
callback functions to handle EAP type specific processing of the version
field and payload.
Fragmentation is now done as a separate step to clean up the design and to
allow the same code to be used in both Phase 1 and Phase 2. This adds
support for fragmenting EAP-PEAP/TTLS/FAST Phase 2 (tunneled) data.
Even though we try to disable TLS compression, it is possible that this
cannot be done with all TLS libraries. For example, OpenSSL 0.9.8 does not
seem to have a configuration item for disabling all compression (0.9.9 has
such an option). If compression is used, Phase 2 decryption may end up
producing more data than the input buffer due to compressed data. This
shows up especially with EAP-TNC that uses very compressible data format.
As a workaround, increase the decryption buffer length to (orig_len+500)*3.
This is a hack, but at least it handles most cases. TLS compression should
really be disabled for EAP use of TLS, but since this can show up with
common setups, it is better to handle this case.
