debian - How can I use the kernel function in my C code? -

first, want apologize english, it's not mother language best.

i'm new developer in debian, before cross-plateform code. since cross-plateform isn't in constraint anymore, want close possible kernel.

for example, want use aes crypt file. aes exist in kernel , prefer use aes kernel rather aes (i trust more kernel source code). there way use kernel function in user space ? more precisely, exist method, or documentation ?

if want have doc of c function, "man function". there equivalent kernel ?

i hope doesn't make mistake question. thank reading, stack overflow me dozen , dozen time in past, thank you.

edit : sorry, edit post , hope it's better time.

is there way use kernel function in user space?

no, kernel function cannot called directly user space.

you can write kernel module, calls desired function responce request user space.