OpenSSL

OpenSSL is an open source implementation of the TSL cryptographic protocol, and its now-deprecated predecessor, Secure Sockets Layer (SSL) protocol. You can perform some basic operations, such as:

Generate a new self signed Certificate instead of a CSR

• openssl req -x509 -nodes -days 3650 -newkey rsa:2048 -keyout private.key -out public.pem

Output a self-signed certificate instead of a certificate request

-nodes (short for no DES) do not encrypt private key

-x509 Output a self-signed certificate instead of a certificate request

Read CSR

• openssl req -text -noout -in root.csr

Read certificate (CRT)

• openssl x509 -text -noout -in root.crt

Encrypt and decrypt a file (GPG can also be used for encrypting and decrypting files)
Using aes-256-cbc cypher, You will be prompted for a password when encrypting that has to be used for decrypting.

• Encrypt file:

openssl enc -aes-256-cbc -in un_encrypted.data -out encrypted.data

Use file command to verify file type.

file encrypted.data
encrypted.data: openssl enc'd data with salted password

• Decrypt file:

openssl enc -d -aes-256-cbc -in encrypted.data -out un_encrypted.data

Activities

• Encrypt a file using aes-256-cbc cypher using openssl enc command

See also

• Installing a web server/Nginx web server
• encfs
• GPG
• pbcopy macOS command