ENCR(1) BSD General Commands Manual ENCR(1) NAME encr — encrypt, authenticate and decrypt streams of data using a shared key. SYNOPSIS encr [-g] [-d] [-k keyfile] DESCRIPTION encr encrypts or authenticates and decrypts (with -d) using a shared 96-byte key keyfile (provided via -k, or generated with -g and -k). Input is passed via stdin, and output is printed to stdout. encr buffers data into segments for processing and blocks if not enough data is provided, it is unsuitable for interactive encryption/decryption. encr protects confidentiality with AES-256 CTR encryption and checks integrity/authenticity using HMAC with the SHA256 hash function. encr will not pass unauthenticated data to stdout, and aborts when given an unauthenticated, reordered or truncated data stream. encr aborts if keyfile is world accessible. EXIT STATUS The encr utility exits 0 on success, and >0 if an error occurs. EXAMPLE generate a random key file: $ encr -g -k ./secret.key encrypt a plain text: $ encr -k ./secret.key < plain.txt > cipher.txt decrypt a cipher text: $ encr -d -k ./secret.key < cipher.txt > plain.txt BSD March 17, 2017 BSD