key cannot be 0 length

Author: sebastian-carpenter

src/ssl_ech.c

@@ -548,7 +548,7 @@ int SetEchConfigsEx(WOLFSSL_EchConfig** outputConfigs, void* heap,
         echConfig += 2;
 
         /* hpke public_key */
-        if (hpkePubkeyLen > HPKE_Npk_MAX ||
+        if (hpkePubkeyLen == 0 || hpkePubkeyLen > HPKE_Npk_MAX ||
                 hpkePubkeyLen != wc_HpkeKemGetEncLen(workingConfig->kemId)) {
             ret = BUFFER_E;
             break;