libseckey: Add a secure key library

The libseckey is a secure key library to perform secure key operations
with OpenSSL. It provides a framework to create OpenSSL PKEYs with a
secure key attached. Such a PKEY contains the public key parts in clear,
but the private key as secure key blob. Only the private key operations
are actually performed with the secure key, public key operations are
performed in software by OpenSSL. It supports CCA and EP11 secure
keys for RSA and ECC crypto operations.

Because many PKEY method related functions are deprecated since OpenSSL
3.0, two versions of the OpenSSL secure key support are needed. One (using
a PKEY method override) for OpenSSL 1.1.1, and another one (using an own
OpenSSL provider) for OpenSSL 3.0 and later. The desired implementation is
selected automatically at compile time, using OpenSSL version defines. The
interface of both implementations is the same, so a user does not need to
care which one is used.

Reviewed-by: Juergen Christ <jchrist@linux.ibm.com>
Signed-off-by: Ingo Franzki <ifranzki@linux.ibm.com>
Signed-off-by: Jan Höppner <hoeppner@linux.ibm.com>

Makefile

@@ -3,7 +3,8 @@ ARCH := $(shell uname -m | sed -e s/i.86/i386/ -e s/sun4u/sparc64/ -e s/arm.*/ar
 # Include common definitions
 include common.mak
 
-LIB_DIRS = libvtoc libutil libzds libdasd libvmdump libccw libvmcp libekmfweb
+LIB_DIRS = libvtoc libutil libzds libdasd libvmdump libccw libvmcp libekmfweb \
+	   libseckey
 TOOL_DIRS = zipl zdump fdasd dasdfmt dasdview tunedasd \
 	   tape390 osasnmpd qetharp ip_watcher qethconf scripts zconf \
 	   vmconvert vmcp man mon_tools dasdinfo vmur cpuplugd ipl_tools \