Add make target for standalone sk-libfido2

Add a Makefile target for sk-libfido2, the standalone fido2 security
key shared library, suitable for use with the SecurityKeyProvider
option.

Add a new configure option `--with-security-key-standalone` that
optionally sets the shared library target sk-libfido2$(SHLIBEXT), and
adds it to $(TARGETS).

misc.h is required when SK_STANDALONE is defined, because of the use
of `monotime_tv` in `sk_select_by_touch`.

Sets the shared library extension for sk-libfido2 is by setting
`SHLIBEXT` depending on the platform in configure.ac.

Add the shared library to the CI builds in the `sk` target config to
make sure it can compile under the same conditions as
`--with-security-key-builtin`.

Add a libssh-pic.a static library that compiles with `-fPIC` reusing
.c.lo method in sk-dummy.so for use in the shared library sk-libfido2.

Note, a separate static library libssh-pic.a is needed, since defining
-DSK_STANDALONE excludes some symbols needed in sshkey.lo.

1 files changed, 2 insertions, 1 deletions

diff --git a/sk-usbhid.c b/sk-usbhid.c
index 812b28d83..36f089a57 100644
--- a/sk-usbhid.c
+++ b/sk-usbhid.c
@@ -77,10 +77,11 @@
 #define FIDO_CRED_PROT_UV_OPTIONAL_WITH_ID 0
 #endif
 
+# include "misc.h"
+
 #ifndef SK_STANDALONE
 # include "log.h"
 # include "xmalloc.h"
-# include "misc.h"
 /*
  * If building as part of OpenSSH, then rename exported functions.
  * This must be done before including sk-api.h.