burianvlastimil / openssl-file-encryption-decryption-shell-scripts

OpenSSL file encryption / decryption POSIX shell scripts

OpenSSL file encryption / decryption shell scripts

Encryption cipher is AES-256 in CBC mode.

Message digest is SHA-512 (from SHA-2 family); this had changed from SHA-256 used before version 2.0.

They are standard POSIX shell scripts, which should work in any Linux distribution (more precisely, your shell).

Multiple arguments (files) and / or pipes are currently not supported.

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Requirements (dependencies)

openssl >= 1.1.1, df, du, tail, awk

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Download, Authenticity check, and Extract

1. Download the latest release and its signature from here:

   https://github.com/burianvlastimil/openssl-file-encryption-decryption-shell-scripts/releases/latest

2. Go to the download directory, where you have saved the files (note that you need the signature file too).

3. Import my public GPG key:

   gpg --recv-keys 7D2E022E39A88ACF3EF6D4498F37AF4CE46008C3
   

4. Verify autenticity of the archive:

   gpg --verify openssl-encryption.tar.xz.asc openssl-encryption.tar.xz
   

5. Extract the xz packed tarball with:

   tar -xJvf openssl-encryption.tar.xz
   

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Installation

There are basically 3 ways to install the scripts:

1. Easy being to use the Makefile's default location, which is /usr/local/bin:

   sudo make install
   

2. Advanced users may install the scripts wherever they wish, in this example to current directory's ./test sub-directory:

   make install PREFIX=./test
   

   Note 1: the destination directory will be created if it does not exist. Note 2: sudo is not needed in this case, so even non-root users can install them easily.

3. Experts may avoid the Makefile altogether and copy the two files into whichever destination they wish.

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Uninstallation / Removal

It is as simple as the installation method you chose.

1. If you have chosen to use the Makefile method #1, it is as simple as:

   sudo make uninstall
   

2. If you have chosen to use the Makefile method #2, it is also very easy:

   make uninstall PREFIX=./test
   

3. If you have chosen to avoid the makefile, you are advanced enough to handle this.

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Usage

1. Encryption

   encrypt-file-aes256 filename
   

   will always produce the filename with .enc extension, even if you encrypt a file multiple files, for instance the following file:

   filename.enc.enc.enc
   

   has been encrypted 3 times.

2. Decryption

   decrypt-file-aes256 filename.enc
   

   will strip the defined .enc extension and produce a file named:

   filename
   

   Note, that it is entirely possible to decrypt files without the defined extension. In this case we will append .dec to the filename and produce for example:

   filename.dec
   

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Exit codes

0 - Successful encryption / decryption.

1 - Some error occurred.

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Testing

I did the following tests so far:

• every fail exit code has been tested: PASS

• encrypting / decrypting a very small file, 1 KB: PASS

• encrypting / decrypting a medium size file, 15 GB: PASS

• encrypting / decrypting a very large file, 750 GB: PASS

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Reporting bugs and suggestions

Please open a new issue ticket.