VB.NET Requires Chilkat v11.1.0+

openssl enc decrypt

See more Encryption Examples

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

VB.NET

Dim success As Boolean = False

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

Dim crypt As New 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.SetEncodedKey("secret","openssl")

'  Load the file to be decrypted.
Dim fileData As New Chilkat.BinData
success = fileData.LoadFile("qa_data/openssl_enc/hamlet.enc")

'  Decrypt
crypt.VerboseLogging = True
success = crypt.DecryptBd(fileData)
Debug.WriteLine(crypt.LastErrorText)

'  Save the decrypted output.
success = fileData.WriteFile("c:/temp/qa_output/hamlet_dec.xml")

Debug.WriteLine("success = " & success)