gnutls_cipher_decrypt3 - Linux

Overview

gnutls_cipher_decrypt3 is a versatile utility designed to decrypt data encrypted using a variety of cipher algorithms. It is a crucial component of the GnuTLS cryptography library, enabling secure data handling and key management.

Syntax

gnutls_cipher_decrypt3 ALG [IV] [KEY] < INFILE > OUTFILE

Options/Flags

| Option | Description | Default |
|—|—|—|
| ALG | Cipher algorithm to use. | Required |
| IV | Initialization vector (optional for some algorithms). | Required for some algorithms |
| KEY | Cipher key (optional for some algorithms). | Required for some algorithms |
| INFILE | Input file containing encrypted data. | Required |
| OUTFILE | Output file to receive decrypted data. | Required |

Examples

Simple Decryption:

gnutls_cipher_decrypt3 AES-128-CBC IV KEY input.enc output.dec

Decryption with Optional IV and KEY:

gnutls_cipher_decrypt3 AES-256-CFB

Integration in a Script:

#!/bin/bash

# Decrypt multiple files using a specified key
for file in *.enc; do
  gnutls_cipher_decrypt3 AES-128-CFB KEY "$file" "${file%.enc}"
done

Common Issues

  • Incorrect Cipher Algorithm: Ensure that the specified algorithm is supported by the GnuTLS library.
  • Missing IV or KEY: If the algorithm requires an IV or KEY, make sure they are provided correctly.
  • Invalid Input Data: The input file should contain encrypted data in the correct format for the specified algorithm.

Integration

gnutls_cipher_decrypt3 can be combined with other GnuTLS commands for advanced cryptography tasks, such as:

  • gnutls_cert_verify for verifying digital certificates.
  • gnutls_dh_params_dump for generating Diffie-Hellman parameters.
  • gnutls_cli for establishing secure network connections.

Related Commands

  • openssl – A general-purpose cryptography command suite.
  • gpg – A tool for encrypting and signing data.
  • libressl – A modern fork of the OpenSSL library.