General OpenSSL commands

The following commands allow you to generate CSRs, Certificates, Private Keys and other tasks.

Generate a new private key and matching certificate signing request (Unix) 

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

Generate a new private key and matching certificate signing request (Windows)

openssl req -out CSR.csr -pubkey -new -keyout privateKey.key -config .shareopenssl.cmf

Generate a certificate signing request for an existing private key

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

Generate a certificate signing request based on an existing x509 certificate

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

Decrypt private key

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

Remove a passphrase from a private key

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

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Checking commands

Use the following commands to check the information within a Certificate, CSR or Private Key. You can also check CSRs and certificates using our online tools.

Check a certificate signing request

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 keystore

openssl pkcs12 -info -in keyStore.p12

Debugging commands

If you are receiving certificate errors, try one of the following commands to debug a SSL connection. Use our Site Check as well to check the certificate.

Check the MD5 hash of the public 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 certificates (also intermediates) should be shown

openssl s_client -connect https://www.paypal.com:443

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Converting commands

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

Convert DER (.crt .cer .der) to PEM

openssl x509 -inform der -in certificate.cer -out certificate.pem

Convert PEM to DER

openssl x509 -outform der -in certificate.pem -out certificate.der

Convert PKCS#12 (.pfx .p12) to PEM containing both private key and certificates

openssl pkcs12 -in keyStore.pfx -out keyStore.pem -nodes
    add -nocerts for private key only; add -nokeys for certificates only 

Convert (add) a seperate key and certificate to a new keystore of type PKCS#12

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