SignalR. Always Red!!!

[prabha_friend]

Hi All,
Good Evening. It's been a longtime after my last visit. How are you all? Hope all is well and good. Let's jump into the issue:

1. I am developing an app which should be installed on both the PC and Android Phone.
2. Upon receiving a call in the android mobile, while its ringing... I want my app in the PC to look up the details through the incoming call number and the display the details in the dashboard according to the software which is going to use my tool. It may be an inventory tool, or a shop or an accounting firm...
3. I chose signalR as my server (notification Hub). Now I know some C# code And Android Studio (Kotlin) for the android app.
4. The server is starting well and working on the PC but my mobile app is not at all finding it connect or pass the ringing number to the PC.
5. There is no problem in the Windows/PC side but Android.
6. In so far what i have read, An Android system cannot connect through an Https unless a valid SSL Certificate is present and also trusted.
7. I tried to create my own certificate by myself and tried connecting. No use.
8. Please tell me How to get or purchase a valid SSL certificate to connect an Android App to the PC using SSL certificate.

p.s: I tried using openSSL to create my own certificates. I am ready to purchase also but only 15$ per year the most.

Thanks.
With Hope,
Prabhakaran

 

[Jason Lee Hayes]

Hi All,
Good Evening. It's been a longtime after my last visit. How are you all? Hope all is well and good. Let's jump into the issue:

1. I am developing an app which should be installed on both the PC and Android Phone.
2. Upon receiving a call in the android mobile, while its ringing... I want my app in the PC to look up the details through the incoming call number and the display the details in the dashboard according to the software which is going to use my tool. It may be an inventory tool, or a shop or an accounting firm...
3. I chose signalR as my server (notification Hub). Now I know some C# code And Android Studio (Kotlin) for the android app.
4. The server is starting well and working on the PC but my mobile app is not at all finding it connect or pass the ringing number to the PC.
5. There is no problem in the Windows/PC side but Android.
6. In so far what i have read, An Android system cannot connect through an Https unless a valid SSL Certificate is present and also trusted.
7. I tried to create my own certificate by myself and tried connecting. No use.
8. Please tell me How to get or purchase a valid SSL certificate to connect an Android App to the PC using SSL certificate.

p.s: I tried using openSSL to create my own certificates. I am ready to purchase also but only 15$ per year the most.

Thanks.
With Hope,
Prabhakaran

To securely connect your Android app to a PC using SSL, you'll need a valid SSL certificate installed on the PC (acting as a server), and your Android app must trust that certificate. Here's a step-by-step guide to acquiring and using a valid SSL certificate:

Step 1: Purchase or Generate a Valid SSL Certificate

You have two main options:

Option A: Purchase from a Trusted Certificate Authority (CA)

• Recommended for production environments.
• Popular CAs include:
  • Let's Encrypt – Free, automated certificates.
  • DigiCert
  • Sectigo
  • GoDaddy
• You'll typically:
• 
  
• Generate a Certificate Signing Request (CSR) on your PC.
• Submit the CSR to the CA.
• Receive a signed certificate (.crt or .pem) and a CA bundle.

Option B: Use a Self-Signed Certificate

• Suitable for development or internal use.
• You can generate one using OpenSSL:
  
  openssl req -x509 -newkey rsa:4096 -keyout key.pem -out cert.pem -days 365 -nodes
  
  
• Note: Android devices won’t trust self-signed certificates by default—you’ll need to manually install and trust them.

Step 2: Install the Certificate on Your PC

• Configure your server (e.g., Apache, Nginx, or a custom backend) to use the SSL certificate.
• Ensure the server listens on HTTPS (port 443) and serves the certificate correctly.

Step 3: Configure Your Android App

• Trusted CA Certificate: If you used a public CA, Android will trust it automatically.
• Self-Signed Certificate: You must manually install the certificate on the Android device:
• 
  
• Go to Settings > Security > Encryption & Credentials > Install a certificate.
• Choose CA certificate and select your .crt or .pem file.
• Alternatively, embed the certificate in your app and use a custom TrustManager.

More details on Android certificate installation are available in this guide.

Step 4: Validate SSL Connection in Your App

• Use HttpsURLConnection, OkHttp, or similar libraries to connect securely.
• Ensure hostname verification and certificate pinning (if needed) are correctly implemented.