From 69749e8f994b42c8af835d55b3a8be757df7fab9 Mon Sep 17 00:00:00 2001
From: Takashi Kojo <kojo@wolfssl.com>
Date: Thu, 30 Jul 2026 16:20:47 +0900
Subject: [PATCH] Reset MlDsaKey between decode attempts in X509_set_pubkey

---
 src/x509.c                    | 10 ++++++++++
 tests/api/test_ossl_x509_pk.c | 24 ++++++++++++++++++++++++
 2 files changed, 34 insertions(+)

diff --git a/src/x509.c b/src/x509.c
index e481f490d9..1c3109e02c 100644
--- a/src/x509.c
+++ b/src/x509.c
@@ -16600,6 +16600,16 @@ int wolfSSL_X509_set_pubkey(WOLFSSL_X509 *cert, WOLFSSL_EVP_PKEY *pkey)
             PRIVATE_KEY_LOCK();
         #endif
             if (!decodeOk) {
+            #ifdef WOLFSSL_MLDSA_PRIVATE_KEY
+                /* A failed PrivateKeyDecode may leave the level pinned;
+                 * reset the key so PublicKeyDecode auto-detects it from
+                 * the SPKI OID. */
+                wc_MlDsaKey_Free(mldsa);
+                if (wc_MlDsaKey_Init(mldsa, NULL, INVALID_DEVID) != 0) {
+                    XFREE(mldsa, cert->heap, DYNAMIC_TYPE_MLDSA);
+                    return WOLFSSL_FAILURE;
+                }
+            #endif
                 idx = 0;
                 if (wc_MlDsaKey_PublicKeyDecode(mldsa,
                         (const byte*)pkey->pkey.ptr, (word32)pkey->pkey_sz,
diff --git a/tests/api/test_ossl_x509_pk.c b/tests/api/test_ossl_x509_pk.c
index 6c5daffc1d..6f65337403 100644
--- a/tests/api/test_ossl_x509_pk.c
+++ b/tests/api/test_ossl_x509_pk.c
@@ -405,6 +405,30 @@ int test_wolfSSL_X509_set_pubkey(void)
             pubkey = NULL;
         }
     #endif
+
+        /* Public-only EVP_PKEY holding an SPKI: the private-key decode
+         * fails and the fallback public decode must work on a reset key. */
+        {
+            WOLFSSL_EVP_PKEY* spki = NULL;
+            unsigned char der[2048];
+            int derSz = 0;
+            const unsigned char* pp = der;
+            XFILE f = XBADFILE;
+
+            ExpectTrue((f = XFOPEN("./certs/mldsa/mldsa44_pub-spki.der",
+                "rb")) != XBADFILE);
+            ExpectIntGT(derSz = (int)XFREAD(der, 1, sizeof(der), f), 0);
+            if (f != XBADFILE)
+                XFCLOSE(f);
+            ExpectNotNull(spki = wolfSSL_d2i_PUBKEY(NULL, &pp, (long)derSz));
+            ExpectIntEQ(wolfSSL_X509_set_pubkey(x509, spki), WOLFSSL_SUCCESS);
+            ExpectNotNull(pubkey = wolfSSL_X509_get_pubkey(x509));
+            ExpectIntEQ(wolfSSL_EVP_PKEY_id(pubkey), WC_EVP_PKEY_DILITHIUM);
+            wolfSSL_EVP_PKEY_free(pubkey);
+            pubkey = NULL;
+            wolfSSL_EVP_PKEY_free(spki);
+        }
+
         wolfSSL_EVP_PKEY_free(pkey);
         pkey = NULL;
     }