Certificates

Source: sslshopper.com

= General OpenSSL Commands =

openssl req -out CSR.csr -new -newkey rsa:2048 -nodes -keyout privateKey.key
 * Generate a new private key and Certificate Signing Request

openssl req -x509 -sha256 -nodes -days 365 -newkey rsa:2048 -keyout privateKey.key -out certificate.crt
 * Generate a self-signed certificate (see How to Create and Install an Apache Self Signed Certificate for more info)

openssl req -out CSR.csr -key privateKey.key -new
 * Generate a certificate signing request (CSR) for an existing private key

openssl x509 -x509toreq -in certificate.crt -out CSR.csr -signkey privateKey.key
 * Generate a certificate signing request based on an existing certificate

openssl rsa -in privateKey.pem -out newPrivateKey.pem
 * Remove a passphrase from a private key

= Checking Using OpenSSL =

openssl req -text -noout -verify -in CSR.csr
 * Check a Certificate Signing Request (CSR)

openssl rsa -in privateKey.key -check
 * Check a private key

openssl x509 -in certificate.crt -text -noout
 * Check a certificate

openssl pkcs12 -info -in keyStore.p12
 * Check a PKCS#12 file (.pfx or .p12)

= Debugging Using OpenSSL =

openssl x509 -noout -modulus -in certificate.crt | openssl md5 openssl rsa -noout -modulus -in privateKey.key | openssl md5 openssl req -noout -modulus -in CSR.csr | openssl md5
 * Check an MD5 hash of the public key to ensure that it matches with what is in a CSR or private key

openssl s_client -connect www.paypal.com:443
 * Check an SSL connection. All the certificates (including Intermediates) should be displayed

= Converting Using OpenSSL=

openssl x509 -inform der -in certificate.cer -out certificate.pem
 * Convert a DER file (.crt .cer .der) to PEM

openssl x509 -outform der -in certificate.pem -out certificate.der
 * Convert a PEM file to DER

openssl pkcs12 -in keyStore.pfx -out keyStore.pem -nodes
 * 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 -export -out certificate.pfx -inkey privateKey.key -in certificate.crt -certfile CACert.crt
 * Convert a PEM certificate file and a private key to PKCS#12 (.pfx .p12)

= Troubleshooting =


 * Cert tools: https://www.sslshopper.com/ssl-certificate-tools.html


 * References