Generate a Self-Signed Certificate

To Generate a Self-Signed Certificate on MacOS with OpenSSL 3.5

        Note: Commands may vary slightly depending on your system environment.    

1. Generate CA certificate (DER) and private key (PEM)          

   openssl req -x509 -newkey rsa:2048 -keyout ca.key -out ca.crt -outform DER -days 365 -nodes

2. Generate TLS private key in PKCS#1 format:          

   openssl genrsa -out tls.pem.key 2048

3. Generate CSR in PEM format:      

   openssl req -new -key tls.pem.key -out tls.csr

4. Sign the TLS certificate with the CA certificate:            

   openssl x509 -req -in tls.csr -CA ca.crt -CAform DER -CAkey ca.key -CAcreateserial -out tls.crt -days 365 -outform DER

5. Convert private key to DER format (PKCS#1)

   openssl rsa -in tls.pem.key -out tls.key -outform DER

6. Convert certificates to PEM format for trusted certificate stores:            

   openssl x509 -in ca.crt -inform DER -out ca.pem -outform PEM
   openssl x509 -in tls.crt -inform DER -out tls.pem -outform PEM

7. Clean up intermediate files:    

   rm tls.pem.key