(PowerShell) openssl enc decrypt

Demonstrates how to decrypt a file that was encrypted using "openssl enc".

This example shows how to decrypt what was created using this openssl command:

openssl enc -e -aes-256-cbc -in hamlet.xml -out hamlet.enc -pass file:./secret.txt

This example shows how to do this:

openssl enc -d -aes-256-cbc -in hamlet.enc -out hamlet_dec.xml -pass file:./secret.txt

Note: This example requires Chilkat v9.5.0.71 or later.

Chilkat .NET Downloads Chilkat .NET Assemblies

Add-Type -Path "C:\chilkat\ChilkatDotNet47-9.5.0-x64\ChilkatDotNet47.dll"

# This example requires the Chilkat API to have been previously unlocked.
# See Global Unlock Sample for sample code.

$crypt = New-Object Chilkat.Crypt2

# Use aes-256-cbc
$crypt.CryptAlgorithm = "aes"
$crypt.CipherMode = "cbc"
$crypt.KeyLength = 256

# We'll need to set the hash algorithm to either MD5 or SHA256.
# openssl version 1.0.* or earlier used MD5 by default
# openssl version 1.1.* uses SHA-256 for the password to secret key derivation.

# For example, if openssl 1.1.0 was used, we should do this:
$crypt.HashAlgorithm = "sha256"

# This example assumes openssl 1.0.2 was used to encrypt what we're now decrypting:
$crypt.HashAlgorithm = "md5"

# The openssl command we are duplicating is:
# 
#    openssl enc -d -aes-256-cbc -in hamlet.enc -out hamlet_dec.xml -pass file:./secret.txt
# 
# The file secret.txt contains the word "secret".  We could write code to load the contents
# of secret.txt, but instead we'll just do this:
$crypt.SetSecretKeyViaPassword("secret")

# Load the file to be decrypted.
$fileData = New-Object Chilkat.BinData
$success = $fileData.LoadFile("qa_data/openssl_enc/hamlet.enc")

# Decrypt
$success = $crypt.DecryptBd($fileData)

# Save the decrypted output.
$success = $fileData.WriteFile("qa_output/hamlet_dec.xml")

$("success = " + $success)