conv.md

OpenSSL - convert certificates

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

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

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

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

Convert private key from PKCS#1 format to PKCS#8

PKCS#1 format has the following header:

-----BEGIN RSA PRIVATE KEY-`----

while PKCS#8 has:

-----BEGIN PRIVATE KEY-----

To convert it, run:

openssl pkcs8 -topk8 -inform PEM -outform PEM -nocrypt -in pkcs1.key -out pkcs8.key