Fix ML-DSA key cache size check for verify-only builds

.github/workflows/build-and-test-refactor.yml

@@ -53,6 +53,17 @@ jobs:
     - name: Build and test refactor DMA ASAN LMS verify-only XMSS full
       run: cd test-refactor/posix && make clean && make -j DMA=1 ASAN=1 LMS_VERIFY_ONLY=1 WOLFSSL_DIR=../../wolfssl && make run
 
+    # Build and test with ML-DSA in verify-only mode
+    - name: Build and test refactor DMA ASAN MLDSA verify-only
+      run: cd test-refactor/posix && make clean && make -j DMA=1 ASAN=1 MLDSA_VERIFY_ONLY=1 WOLFSSL_DIR=../../wolfssl && make run
+
+    # Build and test with ML-DSA verify-only and a reduced keycache buffer.
+    # 4096 < MLDSA_MAX_BOTH_KEY_DER_SIZE(7520) so this would fail the static
+    # assert without MLDSA_VERIFY_ONLY; it passes because verify-only only
+    # needs MLDSA_MAX_PUB_KEY_DER_SIZE(2614). LMS/XMSS full keys fit in 4096.
+    - name: Build and test refactor DMA ASAN MLDSA verify-only reduced keycache
+      run: cd test-refactor/posix && make clean && make -j DMA=1 ASAN=1 MLDSA_VERIFY_ONLY=1 KEYCACHE_BIG_BUFSIZE=4096 WOLFSSL_DIR=../../wolfssl && make run
+
     # Build and test ASAN build, with wolfCrypt tests enabled.
     - name: Build and test refactor ASAN TESTWOLFCRYPT
       run: cd test-refactor/posix && make clean && make -j ASAN=1 TESTWOLFCRYPT=1 WOLFSSL_DIR=../../wolfssl && make run

.github/workflows/build-and-test.yml

@@ -53,6 +53,17 @@ jobs:
     - name: Build and test DMA ASAN LMS verify-only XMSS full
       run: cd test && make clean && make -j DMA=1 ASAN=1 LMS_VERIFY_ONLY=1 WOLFSSL_DIR=../wolfssl && make run
 
+    # Build and test with ML-DSA in verify-only mode
+    - name: Build and test DMA ASAN MLDSA verify-only
+      run: cd test && make clean && make -j DMA=1 ASAN=1 MLDSA_VERIFY_ONLY=1 WOLFSSL_DIR=../wolfssl && make run
+
+    # Build and test with ML-DSA verify-only and a reduced keycache buffer.
+    # 4096 < MLDSA_MAX_BOTH_KEY_DER_SIZE(7520) so this would fail the static
+    # assert without MLDSA_VERIFY_ONLY; it passes because verify-only only
+    # needs MLDSA_MAX_PUB_KEY_DER_SIZE(2614). LMS/XMSS full keys fit in 4096.
+    - name: Build and test DMA ASAN MLDSA verify-only reduced keycache
+      run: cd test && make clean && make -j DMA=1 ASAN=1 MLDSA_VERIFY_ONLY=1 KEYCACHE_BIG_BUFSIZE=4096 WOLFSSL_DIR=../wolfssl && make run
+
     # Build and test ASAN build, with wolfCrypt tests enabled.
     - name: Build and test ASAN TESTWOLFCRYPT
       run: cd test && make clean && make -j ASAN=1 TESTWOLFCRYPT=1 WOLFSSL_DIR=../wolfssl && make run

src/wh_server_crypto.c

@@ -768,11 +768,16 @@ int wh_Server_CacheExportCurve25519Key(whServerContext* server, whKeyId keyId,
 #endif /* HAVE_CURVE25519 */
 
 #ifdef WOLFSSL_HAVE_MLDSA
-/* The big key cache buffer must be able to hold a full ML-DSA keypair DER,
- * otherwise wh_Server_MlDsaKeyCacheImport() can never succeed. */
+/* When verify-only, the server caches only the public key DER. Otherwise it
+ * must be able to hold a full keypair DER (public + private). */
+#if defined(WOLFSSL_DILITHIUM_VERIFY_ONLY) || defined(WOLFSSL_MLDSA_VERIFY_ONLY)
+#define WH_SERVER_MLDSA_MAX_CACHE_DER_SIZE MLDSA_MAX_PUB_KEY_DER_SIZE
+#else
+#define WH_SERVER_MLDSA_MAX_CACHE_DER_SIZE MLDSA_MAX_BOTH_KEY_DER_SIZE
+#endif
 WH_UTILS_STATIC_ASSERT(
-    WOLFHSM_CFG_SERVER_KEYCACHE_BIG_BUFSIZE >= MLDSA_MAX_BOTH_KEY_DER_SIZE,
-    "WOLFHSM_CFG_SERVER_KEYCACHE_BIG_BUFSIZE too small for ML-DSA keypair DER");
+    WOLFHSM_CFG_SERVER_KEYCACHE_BIG_BUFSIZE >= WH_SERVER_MLDSA_MAX_CACHE_DER_SIZE,
+    "WOLFHSM_CFG_SERVER_KEYCACHE_BIG_BUFSIZE too small for ML-DSA key DER");
 
 int wh_Server_MlDsaKeyCacheImport(whServerContext* ctx, wc_MlDsaKey* key,
                                   whKeyId keyId, whNvmFlags flags,
@@ -788,14 +793,12 @@ int wh_Server_MlDsaKeyCacheImport(whServerContext* ctx, wc_MlDsaKey* key,
         return WH_ERROR_BADARGS;
     }
 
-    /* The key may hold a full keypair, in which case
-     * wh_Crypto_MlDsaSerializeKeyDer() encodes both the public and private key
-     * (wc_MlDsaKey_KeyToDer()), so size for both keys, not just the private key. */
     ret = wh_Server_KeystoreGetCacheSlotChecked(
-        ctx, keyId, MLDSA_MAX_BOTH_KEY_DER_SIZE, &cacheBuf, &cacheMeta);
+        ctx, keyId, WH_SERVER_MLDSA_MAX_CACHE_DER_SIZE, &cacheBuf, &cacheMeta);
     if (ret == WH_ERROR_OK) {
-        ret = wh_Crypto_MlDsaSerializeKeyDer(key, MLDSA_MAX_BOTH_KEY_DER_SIZE,
-                                             cacheBuf, &der_size);
+        ret = wh_Crypto_MlDsaSerializeKeyDer(key,
+                                WH_SERVER_MLDSA_MAX_CACHE_DER_SIZE,
+                                cacheBuf, &der_size);
         WH_DEBUG_SERVER_VERBOSE("keyId:%u, ret:%d\n", keyId, ret);
     }
 
@@ -4718,6 +4721,7 @@ static int _HandleMlDsaKeyGen(whServerContext* ctx, uint16_t magic, int devId,
 #ifdef WOLFSSL_MLDSA_NO_MAKE_KEY
     (void)ctx;
     (void)magic;
+    (void)devId;
     (void)cryptoDataIn;
     (void)inSize;
     (void)cryptoDataOut;
@@ -4828,6 +4832,7 @@ static int _HandleMlDsaSign(whServerContext* ctx, uint16_t magic, int devId,
 #ifdef WOLFSSL_MLDSA_NO_SIGN
     (void)ctx;
     (void)magic;
+    (void)devId;
     (void)cryptoDataIn;
     (void)inSize;
     (void)cryptoDataOut;
@@ -4935,6 +4940,7 @@ static int _HandleMlDsaVerify(whServerContext* ctx, uint16_t magic, int devId,
 #ifdef WOLFSSL_MLDSA_NO_VERIFY
     (void)ctx;
     (void)magic;
+    (void)devId;
     (void)cryptoDataIn;
     (void)inSize;
     (void)cryptoDataOut;
@@ -6370,6 +6376,7 @@ static int _HandleMlDsaKeyGenDma(whServerContext* ctx, uint16_t magic,
 #ifdef WOLFSSL_MLDSA_NO_MAKE_KEY
     (void)ctx;
     (void)magic;
+    (void)devId;
     (void)cryptoDataIn;
     (void)inSize;
     (void)cryptoDataOut;
@@ -6491,6 +6498,7 @@ static int _HandleMlDsaSignDma(whServerContext* ctx, uint16_t magic, int devId,
 #ifdef WOLFSSL_MLDSA_NO_SIGN
     (void)ctx;
     (void)magic;
+    (void)devId;
     (void)cryptoDataIn;
     (void)inSize;
     (void)cryptoDataOut;
@@ -6625,6 +6633,7 @@ static int _HandleMlDsaVerifyDma(whServerContext* ctx, uint16_t magic,
 #ifdef WOLFSSL_MLDSA_NO_VERIFY
     (void)ctx;
     (void)magic;
+    (void)devId;
     (void)cryptoDataIn;
     (void)inSize;
     (void)cryptoDataOut;

test-refactor/posix/Makefile

@@ -110,6 +110,14 @@ ifeq ($(XMSS_VERIFY_ONLY),1)
     DEF += -DWOLFSSL_XMSS_VERIFY_ONLY
 endif
 
+ifeq ($(MLDSA_VERIFY_ONLY),1)
+    DEF += -DWOLFSSL_MLDSA_VERIFY_ONLY
+endif
+
+ifneq ($(KEYCACHE_BIG_BUFSIZE),)
+    DEF += -DWOLFHSM_CFG_SERVER_KEYCACHE_BIG_BUFSIZE=$(KEYCACHE_BIG_BUFSIZE)
+endif
+
 # Support a SHE-capable build
 ifeq ($(SHE),1)
     DEF += -DWOLFHSM_CFG_SHE_EXTENSION

test/Makefile

@@ -152,6 +152,14 @@ ifeq ($(XMSS_VERIFY_ONLY),1)
 	DEF += -DWOLFSSL_XMSS_VERIFY_ONLY
 endif
 
+ifeq ($(MLDSA_VERIFY_ONLY),1)
+	DEF += -DWOLFSSL_MLDSA_VERIFY_ONLY
+endif
+
+ifneq ($(KEYCACHE_BIG_BUFSIZE),)
+	DEF += -DWOLFHSM_CFG_SERVER_KEYCACHE_BIG_BUFSIZE=$(KEYCACHE_BIG_BUFSIZE)
+endif
+
 # Support a SHE-capable build
 ifeq ($(SHE),1)
 	DEF += -DWOLFHSM_CFG_SHE_EXTENSION