Java equivalent of C++ encryption [duplicate]

Answer 1

The code you are converting from uses the openssl library. It carries out a triple-DES encryption using an Initial Vector. The first thing you need to understand is exactly what it's doing (and preferably why).

Unfortunately the openssl documentation isn't terribly thorough (see here) ... though the O'Reilley book Network Security with OpenSSL is quite a bit better (it's a bit out of date, though).

Once you know what needs to be done, you shouldn't have much difficulty coding it in Java using the standard javax.crypto package.

Answer 2

The encryption being used is Triple DES with cipher block chaining

RSA page: source

A cryptographic identifier which indicates a 3DES EDE CBC symmetric cipher.

Answer 3

It looks like EVP_CIPHER_CTX is the “context” structure that's containing the encryption (akin to an object), but the actual cypher being used is EVP_des_ede3_cbc — which would be "des-ede3-cbc" with OpenSSL.encrypt(…) and friends

EDIT: To answer the question (“the corresponding package”), generally you should probably use javax.crypto or (probably “better” for most purposes) bouncycastle (http://www.bouncycastle.org/). But OpenSSL bindings do also exist — just awkward to use and deploy.

Answer 4

The trickiest part of this is the EVP_BytesToKey part, which has been recreated before.

How to decrypt file in Java encrypted with openssl command using AES?

I've also got an object oriented version laying around here, if you are really not up to using that C-like code. For SHA-1, use SHA-1 instead of MD5...

As for the encryption, simply use "DESede/CBC/PKCS5Padding" as algorithm name for your Cipher.getInstance() method and you should be fine.