tldr/pages/common/openssl.md

openssl

OpenSSL is a cryptography toolkit.

• Check an SSL connection

openssl s_client -connect www.paypal.com:443

• Generate new private key and CSR

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

• Read contents of certificate, private key and CSR file

openssl x509 -text -noout -in certificate.crt openssl rsa -check -in privateKey.key openssl req -text -noout -verify -in CSR.csr

• Check if certificate, private key and CSR have the same MD5 hash

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