(PowerShell) AES Encrypt and Decrypt a File

PowerShell demonstrates how to AES encrypt a file of any size, and then decrypt.

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

$crypt.CryptAlgorithm = "aes"

# CipherMode may be "ecb" or "cbc"
$crypt.CipherMode = "cbc"

# KeyLength may be 128, 192, 256
$crypt.KeyLength = 256

# The padding scheme determines the contents of the bytes
# that are added to pad the result to a multiple of the
# encryption algorithm's block size.  AES has a block
# size of 16 bytes, so encrypted output is always
# a multiple of 16.
$crypt.PaddingScheme = 0

# An initialization vector is required if using CBC mode.
# ECB mode does not use an IV.
# The length of the IV is equal to the algorithm's block size.
# It is NOT equal to the length of the key.
$ivHex = "000102030405060708090A0B0C0D0E0F"
$crypt.SetEncodedIV($ivHex,"hex")

# The secret key must equal the size of the key.  For
# 256-bit encryption, the binary secret key is 32 bytes.
# For 128-bit encryption, the binary secret key is 16 bytes.
$keyHex = "000102030405060708090A0B0C0D0E0F101112131415161718191A1B1C1D1E1F"
$crypt.SetEncodedKey($keyHex,"hex")

# Encrypt a file, producing the .aes as output.
# The input file is unchanged, the output .aes contains the encrypted
# contents of the input file.

# Note: The .aes output file has no file format.  It is simply a stream
# of bytes that resembles random binary data.
$inFile = "/Users/chilkat/testData/pdf/sample.pdf"
$outFile = "/Users/chilkat/testData/p7m/sample.pdf.aes"
$success = $crypt.CkEncryptFile($inFile,$outFile)
if ($success -ne $true) {
    $($crypt.LastErrorText)
    exit
}

# For demonstration purposes, a different instance of the object will be used
# for decryption.
$decrypt = New-Object Chilkat.Crypt2

# All settings must match to be able to decrypt:
$decrypt.CryptAlgorithm = "aes"
$decrypt.CipherMode = "cbc"
$decrypt.KeyLength = 256
$decrypt.PaddingScheme = 0
$decrypt.SetEncodedIV($ivHex,"hex")
$decrypt.SetEncodedKey($keyHex,"hex")

# Decrypt the .aes
$inFile = "/Users/chilkat/testData/p7m/sample.pdf.aes"
$outFile = "/Users/chilkat/testData/pdf/recovered.pdf"
$success = $decrypt.CkDecryptFile($inFile,$outFile)
if ($success -eq $false) {
    $($decrypt.LastErrorText)
    exit
}

$("Success!")