Chapter 1. libkcapi - Linux Kernel Crypto API User Space Interface Library

Table of Contents

Version Number Schema
Purpose Of AF_ALG

This documentation applies to version 1.2.0.

The Linux kernel exports a network interface of type AF_ALG to allow user space to utilize the kernel crypto API.

libkcapi uses this network interface and exports easy to use APIs so that a developer does not need to consider the low-level network interface handling.

The library does not implement any cipher algorithms. All consumer requests are sent to the kernel for processing. Results from the kernel crypto API are returned to the consumer via the library API.

The kernel interface and therefore this library can be used by unprivileged processes.

Version Number Schema

The version numbers for this library have the following schema: MAJOR.MINOR.PATCHLEVEL

Changes in the major number implies API and ABI incompatible changes, or functional changes that require consumer to be updated (as long as this number is zero, the API is not considered stable and can change without a bump of the major version).

Changes in the minor version are API compatible, but the ABI may change. Functional enhancements only are added. Thus, a consumer can be left unchanged if enhancements are not considered. The consumer only needs to be recompiled.

Patchlevel changes are API / ABI compatible. No functional changes, no enhancements are made. This release is a bug fixe release only. The consumer can be left unchanged and does not need to be recompiled.