diff --git a/wolfcrypt/src/dh.c b/wolfcrypt/src/dh.c
index 55d82c0e23..b57ce7d8e1 100644
--- a/wolfcrypt/src/dh.c
+++ b/wolfcrypt/src/dh.c
@@ -1713,6 +1713,9 @@ int wc_DhCheckPubValue(const byte* prime, word32 primeSz, const byte* pub,
     int ret = 0;
     word32 i;
 
+    if (prime == NULL || pub == NULL)
+        return BAD_FUNC_ARG;
+
     for (i = 0; i < pubSz && pub[i] == 0; i++) {
     }
     pubSz -= i;
diff --git a/wolfcrypt/src/ecc.c b/wolfcrypt/src/ecc.c
index a3e708e989..2453f4445d 100644
--- a/wolfcrypt/src/ecc.c
+++ b/wolfcrypt/src/ecc.c
@@ -10982,16 +10982,24 @@ static int _ecc_import_x963_ex2(const byte* in, word32 inLen, ecc_key* key,
     if (err == MP_OKAY) {
     #ifdef HAVE_COMP_KEY
         /* adjust inLen if compressed */
-        if (compressed)
-            inLen = inLen*2 + 1;  /* used uncompressed len */
+        if (compressed) {
+            /* a compressed coordinate cannot exceed MAX_ECC_BYTES; bound it
+             * before doubling so inLen*2 + 1 cannot overflow word32. */
+            if (inLen > MAX_ECC_BYTES)
+                err = BAD_FUNC_ARG;
+            else
+                inLen = inLen*2 + 1;  /* used uncompressed len */
+        }
     #endif
 
         /* determine key size */
-        keysize = (int)(inLen>>1);
-        /* NOTE: FIPS v6.0.0 or greater, no restriction on imported keys, only
-         *       on created keys or signatures */
-        err = wc_ecc_set_curve(key, keysize, curve_id);
-        key->type = ECC_PUBLICKEY;
+        if (err == MP_OKAY) {
+            keysize = (int)(inLen>>1);
+            /* NOTE: FIPS v6.0.0 or greater, no restriction on imported keys,
+             *       only on created keys or signatures */
+            err = wc_ecc_set_curve(key, keysize, curve_id);
+            key->type = ECC_PUBLICKEY;
+        }
     }
 
     /* read data */
diff --git a/wolfcrypt/src/kdf.c b/wolfcrypt/src/kdf.c
index 4ae7d584f9..90ef96a4bf 100644
--- a/wolfcrypt/src/kdf.c
+++ b/wolfcrypt/src/kdf.c
@@ -89,6 +89,10 @@ int wc_PRF(byte* result, word32 resLen, const byte* secret,
     Hmac   hmac[1];
 #endif
 
+    if ((result == NULL && resLen  != 0) || (secret == NULL && secLen  != 0) ||
+       (seed   == NULL && seedLen != 0))
+      return BAD_FUNC_ARG;
+
     switch (hash) {
     #ifndef NO_MD5
         case md5_mac:
@@ -234,8 +238,18 @@ int wc_PRF_TLSv1(byte* digest, word32 digLen, const byte* secret,
     WC_DECLARE_VAR(sha_result, byte, MAX_PRF_DIG, heap); /* digLen is real size */
     WC_DECLARE_VAR(labelSeed, byte, MAX_PRF_LABSEED, heap);
 
+    if ((digest == NULL && digLen  != 0) ||
+        (secret == NULL && secLen  != 0) ||
+        (label  == NULL && labLen  != 0) ||
+        (seed   == NULL && seedLen != 0)) {
+        return BAD_FUNC_ARG;
+    }
+
+    /* labLen + seedLen is checked with subtraction to avoid word32 wraparound
+     * (the labLen bound first ensures MAX_PRF_LABSEED - labLen cannot
+     * underflow). */
     if (half > MAX_PRF_HALF ||
-        labLen + seedLen > MAX_PRF_LABSEED ||
+        labLen > MAX_PRF_LABSEED || seedLen > (MAX_PRF_LABSEED - labLen) ||
         digLen > MAX_PRF_DIG)
     {
         return BUFFER_E;
@@ -251,8 +265,10 @@ int wc_PRF_TLSv1(byte* digest, word32 digLen, const byte* secret,
     sha_half = secret + half - secLen % 2;
     md5_result = digest;
 
-    XMEMCPY(labelSeed, label, labLen);
-    XMEMCPY(labelSeed + labLen, seed, seedLen);
+    if (labLen != 0)
+        XMEMCPY(labelSeed, label, labLen);
+    if (seedLen != 0)
+        XMEMCPY(labelSeed + labLen, seed, seedLen);
 
     if ((ret = wc_PRF(md5_result, digLen, md5_half, half, labelSeed,
                                 labLen + seedLen, md5_mac, heap, devId)) == 0) {
@@ -286,6 +302,13 @@ int wc_PRF_TLS(byte* digest, word32 digLen, const byte* secret, word32 secLen,
 {
     int ret = 0;
 
+    if ((digest == NULL && digLen  != 0) ||
+        (secret == NULL && secLen  != 0) ||
+        (label  == NULL && labLen  != 0) ||
+        (seed   == NULL && seedLen != 0)) {
+        return BAD_FUNC_ARG;
+    }
+
 #ifdef WOLFSSL_DEBUG_TLS
     WOLFSSL_MSG("  secret");
     WOLFSSL_BUFFER(secret, secLen);
@@ -298,15 +321,19 @@ int wc_PRF_TLS(byte* digest, word32 digLen, const byte* secret, word32 secLen,
     if (useAtLeastSha256) {
         WC_DECLARE_VAR(labelSeed, byte, MAX_PRF_LABSEED, 0);
 
-        if (labLen + seedLen > MAX_PRF_LABSEED) {
+        /* Checked with subtraction to avoid word32 wraparound of
+         * labLen + seedLen. */
+        if (labLen > MAX_PRF_LABSEED || seedLen > (MAX_PRF_LABSEED - labLen)) {
             return BUFFER_E;
         }
 
         WC_ALLOC_VAR_EX(labelSeed, byte, MAX_PRF_LABSEED, heap,
             DYNAMIC_TYPE_DIGEST, return MEMORY_E);
 
-        XMEMCPY(labelSeed, label, labLen);
-        XMEMCPY(labelSeed + labLen, seed, seedLen);
+        if (labLen != 0)
+            XMEMCPY(labelSeed, label, labLen);
+        if (seedLen != 0)
+            XMEMCPY(labelSeed + labLen, seed, seedLen);
 
         /* If a cipher suite wants an algorithm better than sha256, it
          * should use better. */
diff --git a/wolfcrypt/src/rsa.c b/wolfcrypt/src/rsa.c
index cd66eab2ef..8e900932e4 100644
--- a/wolfcrypt/src/rsa.c
+++ b/wolfcrypt/src/rsa.c
@@ -1825,7 +1825,7 @@ static int RsaUnPad_OAEP(byte *pkcsBlock, unsigned int pkcsBlockLen,
     if (ret != 0) {
         ForceZero(tmp, hLen);
 #ifdef WOLFSSL_SMALL_STACK
-        XFREE(tmp, NULL, DYNAMIC_TYPE_RSA_BUFFER);
+        XFREE(tmp, heap, DYNAMIC_TYPE_RSA_BUFFER);
 #elif defined(WOLFSSL_CHECK_MEM_ZERO)
         wc_MemZero_Check(tmp, hLen);
 #endif
@@ -5412,7 +5412,11 @@ int wc_MakeRsaKey(RsaKey* key, int size, long e, WC_RNG* rng)
         goto out;
     }
 
+#if defined(HAVE_FIPS)
+    if (e < WC_RSA_EXPONENT || (e & 1) == 0) {
+#else
     if (e < 3 || (e & 1) == 0) {
+#endif
         err = BAD_FUNC_ARG;
         goto out;
     }