Clear some data before releasing them

java/android/OlmLibSdk/olm-sdk/src/main/jni/olm_inbound_group_session.cpp

@@ -307,6 +307,7 @@ JNIEXPORT jbyteArray OLM_INBOUND_GROUP_SESSION_FUNC_DEF(decryptMessageJni)(JNIEn
 
                 if (plainTextMsgPtr)
                 {
+                    memset(plainTextMsgPtr, 0, maxPlainTextLength*sizeof(uint8_t));
                     free(plainTextMsgPtr);
                 }
             }

java/android/OlmLibSdk/olm-sdk/src/main/jni/olm_outbound_group_session.cpp

@@ -129,6 +129,8 @@ JNIEXPORT void OLM_OUTBOUND_GROUP_SESSION_FUNC_DEF(initOutboundGroupSessionJni)(
                 LOGD(" ## initOutboundGroupSessionJni(): success - result=%lu", static_cast<long unsigned int>(sessionResult));
             }
 
+            // clear the random buffer
+            memset(randomBuffPtr, 0, randomLength);
             free(randomBuffPtr);
         }
     }