Implement server-side support for sk-ecdsa U2F-backed keys (#142) * Implement server-side support for sk-ecdsa U2F-backed keys * Fix out-of-bounds read on normal ecdsa-sha2-[identifier] keys * Fix one more potential out-of-bounds read * Check if nistp256 curve is used in sk-ecdsa-sha2- key It's the only allowed curve per PROTOCOL.u2f specification * Implement server-side support for sk-ed25519 FIDO2-backed keys * Keys with type sk-* make no sense as host keys, so they should be disabled * fix typo * Make sk-ecdsa call buf_ecdsa_verify This reduces code duplication, the SK code just handles the different message format. * Reduce sk specific code The application id can be stored in signkey, then we don't need to call sk-specific functions from svr-authpubkey * Remove debugging output, which causes compilation errors with DEBUG_TRACE disabled * Proper cleanup of sk_app Co-authored-by: Matt Johnston <[email protected]>

--- a/Makefile.in	Sat Jan 22 12:46:08 2022 +0800
+++ b/Makefile.in	Sat Jan 22 16:53:04 2022 +0300
@@ -35,8 +35,8 @@
 		signkey.o rsa.o dbrandom.o \
 		queue.o \
 		atomicio.o compat.o fake-rfc2553.o \
-		ltc_prng.o ecc.o ecdsa.o crypto_desc.o \
-		curve25519.o ed25519.o \
+		ltc_prng.o ecc.o ecdsa.o sk-ecdsa.o crypto_desc.o \
+		curve25519.o ed25519.o sk-ed25519.o \
 		dbmalloc.o \
 		gensignkey.o gendss.o genrsa.o gened25519.o