Error using password-less PFX certificate in Android Kotlin Volley API call

Question

I am encountering an issue while making an API call in my Android Kotlin app using a password-less PFX certificate. The error varies depending on whether I pass null or an empty password ("".toCharArray() or CharArray(0)) while loading into keystore. I am using Volley for the network request.

    private fun apiCall() {
        try {
            val url = "https://api.sample.xyz"

            val jsonBody = JSONObject()
            jsonBody.put("id", "12345678901234567890")

            val headers = HashMap<String, String>()
            headers["user"] = "userName"

            val request = object : JsonObjectRequest(
                Method.POST, url, jsonBody,
                Response.Listener { response ->
                    val result = response.toString()
                    Log.d("API Response", result)
                },
                Response.ErrorListener { error ->
                    Log.d("API Response", error.message.toString())
                    throw error
                }
            ) {
                override fun getHeaders(): MutableMap<String, String> {
                    return headers
                }
            }

            // Initialize the RequestQueue using HurlStack with custom SSL socket factory
            val requestQueue: RequestQueue = Volley.newRequestQueue(
                applicationContext,
                HurlStack(null, pfxSsSocketFactory())
            )

            // Add the request to the RequestQueue.
            requestQueue.add(request)
        } catch (e: Exception) {
            e.printStackTrace()
            // Handle any other exceptions here
        }
    }

    private fun pfxSsSocketFactory(): SSLSocketFactory {
        try {
            val keyStore = KeyStore.getInstance("PKCS12")

            // Load PFX certificate
            val certificateInputStream = resources.openRawResource(R.raw.apiscertificate)
            val password = null
            keyStore.load(certificateInputStream, password)

            // Check the type of the private key entry
            val alias = keyStore.aliases().nextElement()
            val privateKey = keyStore.getKey(alias, password)

            if (privateKey is java.security.interfaces.RSAPrivateKey) {
                // RSA key, continue with the SSLContext setup
                val keyManagerFactory = KeyManagerFactory.getInstance("X509")
                keyManagerFactory.init(keyStore, password)

                // Create an SSLContext that uses the KeyManager
                val sslContext = SSLContext.getInstance("TLS")
                sslContext.init(keyManagerFactory.keyManagers, null, null)

                return sslContext.socketFactory
            } else {
                throw RuntimeException("Unsupported private key type")
            }
        } catch (e: Exception) {
            throw RuntimeException("Error creating SSL socket factory", e)
        }
    }

I have tried various approaches to load the PFX certificate, including passing null, "".toCharArray(), and CharArray(0) as the password. However, none of these approaches have resolved the issue.

When passing null as the password, I receive the error:

Caused by: java.lang.NullPointerException: no password supplied when one expected

When passing either "".toCharArray() or CharArray(0) as the password, I receive the error:

Caused by: java.io.IOException: PKCS12 key store mac invalid - wrong password or corrupted file.

I am looking for alternative approaches or suggestions to successfully make an API call using a password-less PFX certificate without encountering the mentioned errors. If there are any other methods or best practices for handling password-less certificates in Android Kotlin using Volley or other libraries, please provide insights or examples. I appreciate any guidance or recommendations to resolve this issue effectively.