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The Most Common OpenSSL Commands

General OpenSSL Commands

These commands allow you to generate CSRs, Certificates, Private Keys and do other miscellaneous tasks.

Generate a new private key and Certificate Signing Request

openssl req -out CSR.csr -new -newkey rsa:2048 -nodes -keyout privateKey.key

Generate a self-signed certificate (see How to Create and Install an Apache Self Signed Certificate for more info)

openssl req -x509 -sha256 -nodes -days 365 -newkey rsa:2048 -keyout privateKey.key -out certificate.crt

Generate a certificate signing request (CSR) for an existing private key

openssl req -out CSR.csr -key privateKey.key -new

Generate a certificate signing request based on an existing certificate

openssl x509 -x509toreq -in certificate.crt -out CSR.csr -signkey privateKey.key

Remove a passphrase from a private key

openssl rsa -in privateKey.pem -out newPrivateKey.pem

Checking Using OpenSSL

If you need to check the information within a Certificate, CSR or Private Key, use these commands. You can also check CSRs and check certificates using our online tools.

Check a Certificate Signing Request (CSR)

openssl req -text -noout -verify -in CSR.csr

Check a private key

openssl rsa -in privateKey.key -check

Check a certificate

openssl x509 -in certificate.crt -text -noout

Check a PKCS#12 file (.pfx or .p12)

openssl pkcs12 -info -in keyStore.p12

Debugging Using OpenSSL

If you are receiving an error that the private doesn't match the certificate or that a certificate that you installed to a site is not trusted, try one of these commands. If you are trying to verify that an SSL certificate is installed correctly, be sure to check out the SSL Checker.

Check an MD5 hash of the public key to ensure that it matches with what is in a CSR or private key

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 SSL connection. All the certificates (including Intermediates) should be displayed

openssl s_client -connect www.paypal.com:443

Converting Using OpenSSL

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. Use our SSL Converter to convert certificates without messing with OpenSSL.

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

Source

 

View CRL

openssl crl -inform DER -text -noout -in crl.crl
openssl crl -inform PEM -text -noout -in crl.crl

 

Generate a request for Windows CA Services

The process below shows an "easy" way to add the certificateTemplateName to the certificate request that will be submitted to Windows CA Services.

  1. Create an openssl configuration file for your request based on the template shown below.
    1. Make sure you update all the subject alternative names entries.
  2. Use the script below to create the certificate request.
# FILE: server.mydomain.com.openssl.cnf
#
# run the following to generate the request:
# openssl req -newkey rsa:2048 -keyout server.mydomain.com -out server.mydomain.com.req -nodes -config server.mydomain.com.openssl.cnf

oid_section = OIDs

[OIDs]
certificateTemplateName = 1.3.6.1.4.1.311.20.2

[req]
default_bits = 2048
distinguished_name = req_distinguished_name
req_extensions = req_ext

[req_distinguished_name]
countryName = Country Name (2 letter code)
countryName_default = US
stateOrProvinceName = State or Province Name (full name)
stateOrProvinceName_default = My State
localityName = Locality Name (eg, city)
localityName_default = My City
organizationalUnitName    = Organizational Unit Name (eg, section)
organizationalUnitName_default    = My Org
commonName = Common Name
commonName_default = server.mydomain.com
commonName_max    = 64

[req_ext]
subjectAltName = @alt_names

# Replace PKI-WebServer with your certificate template name, NOT the display name
certificateTemplateName = ASN1:PRINTABLESTRING:PKI-WebServer

[alt_names]
DNS.1 = server.mydomain.com
DNS.2 = server1.mydomain.com
DNS.3 = server2.mydomain.com
IP.1 = 10.1.2.3

#!/bin/bash

# change this to match your certificate primary common name
CERTBASE="server.mydomain.com"

# generate timestamp
printf -v TIMESTAMP '%(%Y%m%d-%H%M%S)T' -1

# generate new private key and csr
openssl req -newkey rsa:2048 -keyout "$CERTBASE.$TIMESTAMP.key" -out "$CERTBASE.$TIMESTAMP.req" -nodes -config "$CERTBASE.openssl.cnf"

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