LAB: Using openssl to encrypt and decrypt

Here are steps to replicate the demo in my symmetric encryption video.

• Create a text file named plaintext containing some text. Whatever you want.

• Generate a random 16-byte (32-hexadecimal-digit) key K using this command:

  openssl rand -hex 16
• Generate another 32-hex-digit number to be your initialization vector IV.

• Encrypt your file:

  openssl enc -aes-128-cbc -K YOUR_K -iv YOUR_IV -in plaintext -out ciphertext
• Do cat ciphertext just to see what you ended up with.
• Well that was probably unsatisfying! Try cat ciphertext | hexdump -C.

• Let's see if we can decrypt this baby.

  openssl enc -d -aes-128-cbc -K YOUR_K -iv YOUR_IV -in ciphertext -out decrypted

• Check to see whether you got what you hoped for.

  cat decrypted diff decrypted plaintext