I used Java to build a command line app that offers both symmetric and asymmetric cryptographic functionality.

GitHub 

Symmetric

Uses the cryptographically secure function KMACXOF256 to:

• Compute a plain cryptographic hash of given text (text file or command line input).

• Compute an authentication tag (MAC) of given text (text file or command line input) under a given passphrase.

• Encrypt a given data file symmetrically under a given passphrase.

• Decrypt a given symmetric cryptogram under a given passphrase.

Asymmetric 

Uses DHIES encryption and Schnorr signatures with elliptic curves to:

• Generate an elliptic key pair from a given passphrase and write the public key to a file.

• Encrypt given text (text file or command line input) under a given elliptic public key file and write the ciphertext to a file.

• Decrypt a given elliptic-encrypted file from a given password and write the decrypted data to a file.

• Sign given text (text file or command line input) from a given password and write the signature to a file.

• Verify a given data file and its signature file under a given public key file.