This enables definition of keys where the PEM form is not evailable,
for example from JSON Web Key (JWK) files.

Ref: https://tools.ietf.org/html/rfc7517#section-9.3

The full suite is still available via a Makefile.am modification

Ref: https://github.com/varnishcache/varnish-cache/commit/5450550906d0809dfc21ae9d3a5b14446c1809d4

ref: 0c74d1b99f1f43fc99725fe14322760afa7858ee

This reverts commit a38d3232.

This reverts commit a1e61657.

This reverts commit 3a7f6d62.

I would have thought that for our usecase (we only ever access a copy
of an md ctx in a single thread) we do not need this, but due to strange
error output on CentOS 7.2.1511 libcrypto 1.0.1e, add it to be on the
safe side:

-   Debug          "vauth_sig.valid() failed%00"
-   Debug          "crypto 139880179115568:error:04091068:lib(4):func(145):reason(104):rsa_sign.c:287:%0a%00"

The interesting bit is the %00 at the end of both lines

older openssl versions do not support -nosalt (but also do not
complain about it). So we pre-generate key/iv for all the existing
textual keys (equalling the file size) on a new openssl and
use those.

good it doesn't, I was already wondering about this odd concept

with high concurrency, possibly related to context switching,
dd would read a short block.

Fix this using the fullblock flag

This will leave a bit less of a mess, yet the build system is still
not entirely connect, for instance, out-of-tree builds will not work.