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/ed25519.h	Sat Jan 22 12:46:08 2022 +0800
+++ b/ed25519.h	Sat Jan 22 16:53:04 2022 +0300
@@ -27,6 +27,7 @@
 
 #include "includes.h"
 #include "buffer.h"
+#include "signkey.h"
 
 #if DROPBEAR_ED25519 
 
@@ -43,7 +44,8 @@
 #if DROPBEAR_SIGNKEY_VERIFY
 int buf_ed25519_verify(buffer * buf, const dropbear_ed25519_key *key, const buffer *data_buf);
 #endif
-int buf_get_ed25519_pub_key(buffer* buf, dropbear_ed25519_key *key);
+int buf_get_ed25519_pub_key(buffer *buf, dropbear_ed25519_key *key,
+        enum signkey_type expect_keytype);
 int buf_get_ed25519_priv_key(buffer* buf, dropbear_ed25519_key *key);
 void buf_put_ed25519_pub_key(buffer* buf, const dropbear_ed25519_key *key);
 void buf_put_ed25519_priv_key(buffer* buf, const dropbear_ed25519_key *key);