autoconf pieces for U2F support

Mostly following existing logic for PKCS#11 - turning off support
when either libcrypto or dlopen(3) are unavailable.

1 files changed, 11 insertions, 0 deletions

diff --git a/ssh-sk-helper.c b/ssh-sk-helper.c
index 0a0c92a44..ced00d955 100644
--- a/ssh-sk-helper.c
+++ b/ssh-sk-helper.c
@@ -51,6 +51,7 @@
 #include "ssherr.h"
 #include "ssh-sk.h"
 
+#ifdef ENABLE_SK
 extern char *__progname;
 
 int
@@ -141,3 +142,13 @@ main(int argc, char **argv)
 
         return (0);
 }
+#else /* ENABLE_SK */
+#include <stdio.h>
+
+int
+main(int argc, char **argv)
+{
+        fprintf(stderr, "ssh-sk-helper: disabled at compile time\n");
+        return -1;
+}
+#endif /* ENABLE_SK */