1 files changed, 6 insertions, 0 deletions

diff --git a/scard-opensc.c b/scard-opensc.c
index e8e12dd85..4ab87ea8a 100644
--- a/scard-opensc.c
+++ b/scard-opensc.c
@@ -89,6 +89,12 @@ sc_init(void)
         r = sc_establish_context(&ctx, "openssh");
         if (r)
                 goto err;
+        if (sc_reader_id >= ctx->reader_count) {
+                r = SC_ERROR_NO_READERS_FOUND;
+                error("Illegal reader number %d (max %d)", sc_reader_id, 
+                    ctx->reader_count -1);
+                goto err;
+        }
         r = sc_connect_card(ctx->reader[sc_reader_id], 0, &card);
         if (r)
                 goto err;