upstream: Correct some bugs in PKCS#11 token PIN handling at

initial login, the attempt at reading the PIN could be skipped in some cases
especially on devices with integrated PIN readers.

based on patch from Daniel Kucera in bz#2652; ok markus@

OpenBSD-Commit-ID: fad70a61c60610afe8bb0db538c90e343e75e58e

1 files changed, 22 insertions, 12 deletions

diff --git a/ssh-pkcs11.c b/ssh-pkcs11.c
index 384ac1edb..f116e4051 100644
--- a/ssh-pkcs11.c
+++ b/ssh-pkcs11.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: ssh-pkcs11.c,v 1.40 2019/01/22 12:00:50 djm Exp $ */
+/* $OpenBSD: ssh-pkcs11.c,v 1.41 2019/01/22 12:03:58 djm Exp $ */
 /*
  * Copyright (c) 2010 Markus Friedl.  All rights reserved.
  * Copyright (c) 2014 Pedro Martelletto. All rights reserved.
@@ -620,26 +620,36 @@ static int
 pkcs11_open_session(struct pkcs11_provider *p, CK_ULONG slotidx, char *pin,
     CK_ULONG user)
 {
-        CK_RV                   rv;
+        struct pkcs11_slotinfo  *si;
         CK_FUNCTION_LIST        *f;
+        CK_RV                   rv;
         CK_SESSION_HANDLE       session;
-        int                     login_required, ret;
+        int                     login_required, have_pinpad, ret;
 
         f = p->function_list;
-        login_required = p->slotinfo[slotidx].token.flags & CKF_LOGIN_REQUIRED;
-        if (pin && login_required && !strlen(pin)) {
+        si = &p->slotinfo[slotidx];
+
+        have_pinpad = si->token.flags & CKF_PROTECTED_AUTHENTICATION_PATH;
+        login_required = si->token.flags & CKF_LOGIN_REQUIRED;
+
+        /* fail early before opening session */
+        if (login_required && !have_pinpad && pin != NULL && strlen(pin) == 0) {
                 error("pin required");
                 return (-SSH_PKCS11_ERR_PIN_REQUIRED);
         }
         if ((rv = f->C_OpenSession(p->slotlist[slotidx], CKF_RW_SESSION|
-            CKF_SERIAL_SESSION, NULL, NULL, &session))
-            != CKR_OK) {
+            CKF_SERIAL_SESSION, NULL, NULL, &session)) != CKR_OK) {
                 error("C_OpenSession failed: %lu", rv);
                 return (-1);
         }
-        if (login_required && pin) {
-                rv = f->C_Login(session, user,
-                    (u_char *)pin, strlen(pin));
+        if (login_required) {
+                if (have_pinpad && (pin == NULL || strlen(pin) == 0)) {
+                        /* defer PIN entry to the reader keypad */
+                        rv = f->C_Login(session, CKU_USER, NULL_PTR, 0);
+                } else {
+                        rv = f->C_Login(session, CKU_USER,
+                            (u_char *)pin, strlen(pin));
+                }
                 if (rv != CKR_OK && rv != CKR_USER_ALREADY_LOGGED_IN) {
                         error("C_Login failed: %lu", rv);
                         ret = (rv == CKR_PIN_LOCKED) ?
@@ -649,9 +659,9 @@ pkcs11_open_session(struct pkcs11_provider *p, CK_ULONG slotidx, char *pin,
                                 error("C_CloseSession failed: %lu", rv);
                         return (ret);
                 }
-                p->slotinfo[slotidx].logged_in = 1;
+                si->logged_in = 1;
         }
-        p->slotinfo[slotidx].session = session;
+        si->session = session;
         return (0);
 }