Simple file/stream encryption using OpenSSL

decrypt

#!/usr/bin/env bash
set -e

[ -n "$KEY_DIR" ] || KEY_DIR="$HOME/.keys"

read -r -a line
if [ "${line[0]}" = "key:" ] && [ -n "${line[1]}" ]; then
  KEY_NAME="${line[1]}"
else
  echo "decrypt: invalid input" >&2
  exit 1
fi

KEY_FILE="${KEY_DIR%/}/$KEY_NAME"
[ -f "$KEY_FILE" ] || {
  echo "decrypt: key file not found: $KEY_FILE" >&2
  exit 2
}

openssl aes-256-cbc -d -a -pass file:"$KEY_FILE"

encrypt

#!/usr/bin/env bash
set -e

[ -n "$KEY_DIR" ] || KEY_DIR="$HOME/.keys"

KEY_NAME="$1"
[ -n "$KEY_NAME" ] || {
  echo "usage: encrypt <key-name>" >&2
  exit 1
}

KEY_FILE="${KEY_DIR%/}/$KEY_NAME"
[ -f "$KEY_FILE" ] || {
  echo "encrypt: key file not found: $KEY_FILE" >&2
  exit 2
}

echo "key: $KEY_NAME"
openssl aes-256-cbc -a -salt -pass file:"$KEY_FILE"

mkkey

#!/usr/bin/env bash
set -e

[ -n "$KEY_DIR" ] || KEY_DIR="$HOME/.keys"
mkdir -p "$KEY_DIR"

KEY_NAME="$1"
[ -n "$KEY_NAME" ] || {
  echo "usage: mkkey <key-name>" >&2
  exit 1
}

KEY_FILE="${KEY_DIR%/}/$KEY_NAME"
[ ! -f "$KEY_FILE" ] || {
  echo "mkkey: file exists: $KEY_FILE" >&2
  exit 2
}

openssl rand 512 > "$KEY_FILE"

Simple Encryption.md

Simple file/stream encryption using OpenSSL

Create and store a 512-byte random encryption key named secret:

$ mkkey secret

Encrypt the contents of file with the secret key and write it to file.enc:

$ encrypt secret < file > file.enc

Decrypt the contents of file.enc to standard output:

$ decrypt < file.enc

Keys are stored in ~/.keys by default. Set the KEY_DIR environment variable to specify a different location.