Archive for September 1st, 2017

Converting .crt .cer .der to PEM, converting .PEM to .DER and convert .PFX PKCS#12 (.P12) to .PEM file using OpenSSL

Friday, September 1st, 2017

openssl_check_verify_crt_csr_key_certificate_consistency-with-openssl-command-openssl-logo

These commands allow you to convert certificates and keys to different formats to make them compatible with specific types of servers or software. For example, you can convert a normal PEM file that would work with Apache to a PFX (PKCS#12) file and use it with Tomcat or IIS.

  • Convert a DER file (.crt .cer .der) to PEM

     

    openssl x509 -inform der -in certificate.cer -out certificate.pem
    
  • Convert a PEM file to DER

     

    openssl x509 -outform der -in certificate.pem -out certificate.der
    
  • Convert a PKCS#12 file (.pfx .p12) containing a private key and certificates to PEM

     

    openssl pkcs12 -in keyStore.pfx -out keyStore.pem -nodes


    You can add -nocerts to only output the private key or add -nokeys to only output the certificates.

  • Convert a PEM certificate file and a private key to PKCS#12 (.pfx .p12)

     

    openssl pkcs12 -export -out certificate.pfx -inkey privateKey.key \
    -in certificate.crt -certfile CACert.crt