Find in xfrm_input.c how the xfrm_input function determines the protocol type and calls either the ah_input() or the esp_input() function. Briefly describe how a specific open source implementation...

Find in xfrm_input.c how the xfrm_input function determines the protocol type and calls either the ah_input() or the esp_input() function.

Briefly describe how a specific open source implementation of hash algorithm, e.g., MD5, which consists of md5_init , md5_update and md5_final , is executed in the ah_mac_digest function.