[Server] Fix memory issues with script functions used for hashing

apps/openmw-mp/Script/Functions/Miscellaneous.cpp

@@ -9,31 +9,31 @@
 #include <iostream>
 #include <random>
 
-const char *MiscellaneousFunctions::GenerateRandomString(unsigned int length) noexcept
+static std::string tempRandomString;
+static std::string tempHashString;
+
+const char* MiscellaneousFunctions::GenerateRandomString(unsigned int length) noexcept
 {
     const std::string characters = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz";
 
     std::random_device randomDevice;
     std::mt19937 generator(randomDevice());
     std::uniform_int_distribution<std::mt19937::result_type> distribution(0, characters.size() - 1);
-
+    std::string randomString = "";
-    /* WARNING: this function is no longer reentrant with a static variable */
-    static std::string randomString;
 
     for (std::size_t i = 0; i < length; ++i)
     {
         randomString += characters[distribution(generator)];
     }
 
-    return randomString.c_str();
+    tempRandomString = randomString;
+    return tempRandomString.c_str();
 }
 
-const char *MiscellaneousFunctions::GetSHA256Hash(const char* inputString) noexcept
+const char* MiscellaneousFunctions::GetSHA256Hash(const char* inputString) noexcept
 {
-    /* WARNING: this function is no longer reentrant with a static variable */
+    tempHashString = picosha2::hash256_hex_string(std::string{inputString});
-    static std::string hashString = picosha2::hash256_hex_string(std::string{inputString});
+    return tempHashString.c_str();
-
-    return hashString.c_str();
 }
 
 unsigned int MiscellaneousFunctions::GetLastPlayerId() noexcept