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]>

#include "tommath_private.h"
#ifdef BN_MP_ERROR_TO_STRING_C
/* LibTomMath, multiple-precision integer library -- Tom St Denis */
/* SPDX-License-Identifier: Unlicense */

/* return a char * string for a given code */
const char *mp_error_to_string(mp_err code)
{
   switch (code) {
   case MP_OKAY:
      return "Successful";
   case MP_ERR:
      return "Unknown error";
   case MP_MEM:
      return "Out of heap";
   case MP_VAL:
      return "Value out of range";
   case MP_ITER:
      return "Max. iterations reached";
   case MP_BUF:
      return "Buffer overflow";
   default:
      return "Invalid error code";
   }
}

#endif