OpenSSL

Generate cryptographically secure pseudo-random hex or Base64 strings.

Get and store server certificate without using sed.

How to bypass the OpenSSL security level using curl or openssl utility to access legacy services.

Check the consistency of an EC or RSA private key.

Use openssl utility to determine cipher used to encrypt the private key.

Create and encrypt RSA or EC private key using general utilities. There are multiple possibilities, so let me sum it up.

Create and encrypt RSA or EC private key using dedicated utilities.

Different ways to provide encryption password when using OpenSSL utility.

Use OpenSSL utility to encrypt or decrypt files.

Define IP address inside multi-domain SSL certificate.

Check if the certificate matches DNS name or IP address

Create a multi-domain SSL certificate without a common name.

Use the OpenSSL utility to generate a base64-encoded secret.

Use OpenSSL to manage PKCS #12 archive.

Determine SSL cipher suites supported by the web-server using OpenSSL.

Display details for specific OpenSSL cipher, only single one.

Create simple shell script to pretty-print OpenSSL ciphers.

Match certificate and its intermediate counterpart by using X.509 key identifier extension.

Use openssl utility to display and verify the certificate chain for a specific domain.

Match certificate and its private key by comparing the modulus of the certificate to the modulus of the private key.

Use openssl command-line utility to display TLS server extensions.

Use essential openssl utility to quickly determine if your web-server still supports deprecated TLS 1.0 protocol.

Check locally stored SSL certificate using essential utilities like openssl and curl. This knowledge is especially useful when you want to prepare an SSL certificate for a load balancer.

Create a certificate signing request and use it to generate an SSL certificate. I strongly suggest reading my two earlier blog posts about self-signed SSL certificates and private keys as these contain useful information. I will describe three different ways to generate a certificate signing request.

Generate private key for an SSL certificate and verify its consistency.

Use openssl command-line utility to calculate and display days till the certificate expiration.

Use openssl command-line utility to display common name, certificate issuer, alternative names, start/end dates.