From bad522f6549bd9bc16035a94016f765d4642f08c Mon Sep 17 00:00:00 2001
From: Daniele Lacamera <root@danielinux.net>
Date: Tue, 15 Sep 2026 13:24:14 +0200
Subject: [PATCH] F-12942: pkcs11: wipe PIN on terminal init failure

pkcs11_crypto_init() tore down the session on failure but left the
pre-populated pkcs11_pin credential in retained bootloader memory
after the handoff. Wipe it in the failure path, same as the deinit
path (F-12114). Regression test in unit-pkcs11-pin-zeroize: login
rejected -> init fails -> every pin byte is zero.
---
 src/libwolfboot.c                          |  5 ++++
 tools/unit-tests/unit-pkcs11-pin-zeroize.c | 35 +++++++++++++++++++++-
 2 files changed, 39 insertions(+), 1 deletion(-)

diff --git a/src/libwolfboot.c b/src/libwolfboot.c
index 5569d645..932677a1 100644
--- a/src/libwolfboot.c
+++ b/src/libwolfboot.c
@@ -2369,6 +2369,8 @@ static int pkcs11_enc_initialized = 0, pkcs11_dec_initialized = 0;
 static CK_AES_CTR_PARAMS pkcs11_params;
 #endif
 
+static void pkcs11_pin_wipe(void);
+
 int pkcs11_crypto_init(void)
 {
     CK_RV ret = 0;
@@ -2462,6 +2464,9 @@ int pkcs11_crypto_init(void)
         if (pkcs11_initialized) {
             pkcs11_function_list->C_Finalize(NULL);
         }
+        /* terminal failure: the credential must not survive in retained
+         * memory (same reason as the deinit wipe) */
+        pkcs11_pin_wipe();
     }
 
     return ret;
diff --git a/tools/unit-tests/unit-pkcs11-pin-zeroize.c b/tools/unit-tests/unit-pkcs11-pin-zeroize.c
index 591cbe25..8c801eb9 100644
--- a/tools/unit-tests/unit-pkcs11-pin-zeroize.c
+++ b/tools/unit-tests/unit-pkcs11-pin-zeroize.c
@@ -1,6 +1,7 @@
 /* unit-pkcs11-pin-zeroize.c
  *
- * Unit test for the PKCS#11 login credential lifetime (F-12114).
+ * Unit test for the PKCS#11 login credential lifetime (F-12114,
+ * F-12942).
  *
  * pkcs11_pin is a file-scope copy of the credential supplied to
  * C_Login() for the token holding the firmware-decryption key.
@@ -58,6 +59,7 @@ static uint8_t test_encrypt_key[ENCRYPT_PKCS11_KEY_ID_SIZE +
 /* ---- PKCS#11 stubs ---- */
 
 static int stub_close_session_calls;
+static int stub_login_fail;
 
 static CK_RV stub_C_Initialize(CK_VOID_PTR pInitArgs)
 {
@@ -98,6 +100,9 @@ static CK_RV stub_C_Login(CK_SESSION_HANDLE hSession, CK_USER_TYPE userType,
     (void)userType;
     (void)pPin;
     (void)ulPinLen;
+    if (stub_login_fail) {
+        return CKR_PIN_INCORRECT;
+    }
     return CKR_OK;
 }
 
@@ -171,6 +176,7 @@ void panic(void)
 static void reset_stub_state(void)
 {
     stub_close_session_calls = 0;
+    stub_login_fail = 0;
 }
 
 /* F-12114: the pre-handoff deinitializer must erase the PKCS#11
@@ -223,6 +229,32 @@ START_TEST(test_pkcs11_deinit_no_session)
 }
 END_TEST
 
+/* F-12942: a terminal initialization failure after C_Login() was
+ * attempted (login rejected) tears the session down and must also
+ * erase the credential copy: the bootloader memory is retained
+ * after the handoff, as on the deinit path. */
+START_TEST(test_pkcs11_pin_wiped_on_init_failure)
+{
+    int ret;
+    size_t i;
+
+    reset_stub_state();
+    encrypt_initialized = 0;
+    memcpy(pkcs11_pin, ENCRYPT_PKCS11_PIN, sizeof(ENCRYPT_PKCS11_PIN));
+    stub_login_fail = 1;
+
+    ret = pkcs11_crypto_init();
+    stub_login_fail = 0;
+
+    ck_assert_int_eq(ret, CKR_PIN_INCORRECT);
+    ck_assert_int_eq(encrypt_initialized, 0);
+    for (i = 0; i < sizeof(pkcs11_pin); i++) {
+        ck_assert_msg(pkcs11_pin[i] == 0,
+                      "pkcs11_pin byte %zu not wiped", i);
+    }
+}
+END_TEST
+
 Suite *wolfboot_suite(void)
 {
     Suite *s = suite_create("wolfboot-pkcs11-pin");
@@ -230,6 +262,7 @@ Suite *wolfboot_suite(void)
 
     tcase_add_test(tc, test_pkcs11_pin_wiped_on_deinit);
     tcase_add_test(tc, test_pkcs11_deinit_no_session);
+    tcase_add_test(tc, test_pkcs11_pin_wiped_on_init_failure);
     suite_add_tcase(s, tc);
     return s;
 }