From 07e43eda8dc69cecc385a6b3723e155afbc59257 Mon Sep 17 00:00:00 2001
From: NIIBE Yutaka <gniibe@fsij.org>
Date: Fri, 22 Apr 2022 11:50:19 +0900
Subject: [PATCH] scd: Don't inhibit SSH authentication for larger data if it
 can.

* scd/app-openpgp.c (do_auth): Use command chaining if available.

--

Cherry-picked from master branch of:
	e8fb8e2b3e66d5ea8a3dc90afdc14611abf2c3da

GnuPG-bug-id: 5935
Signed-off-by: NIIBE Yutaka <gniibe@fsij.org>
---
 scd/app-openpgp.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/scd/app-openpgp.c b/scd/app-openpgp.c
index c65d6b198..c7d2c383e 100644
--- a/scd/app-openpgp.c
+++ b/scd/app-openpgp.c
@@ -4738,6 +4738,11 @@ do_auth (app_t app, ctrl_t ctrl, const char *keyidstr,
           exmode = 1;    /* Use extended length.  */
           le_value = app->app_local->keyattr[2].rsa.n_bits / 8;
         }
+      else if (app->app_local->cardcap.cmd_chaining && indatalen > 254)
+        {
+          exmode = -254; /* Command chaining with max. 254 bytes.  */
+          le_value = 0;
+        }
       else if (indatalen > 255)
         {
           if (!app->app_local->cardcap.ext_lc_le)