go-openssl/README.md

Luzifer / go-openssl

go-openssl is a small library wrapping the crypto/aes functions in a way the output is compatible to OpenSSL / CryptoJS. For all encryption / decryption processes AES256 is used so this library will not be able to decrypt messages generated with other than openssl aes-256-cbc. If you're using CryptoJS to process the data you also need to use AES256 on that side.

OpenSSL 1.1.0

With the release of OpenSSL 1.1.0c the default hashing algorithm changed from md5 to sha256. Using this new default breaks the en- and decryption used in this library. Currently you need to specify to use md5 hashing when encrypting using openssl enc -aes-256-cbc -a -k yourpassword -md md5. Sadly using sha256 is not a drop-in replacement and therefore needs to be implemented as a separate function following the OpenSSL source code.

Installation

go get github.com/Luzifer/go-openssl

Usage example

The usage is quite simple as you don't need any special knowledge about OpenSSL and/or AES256:

Encrypt

import (
  "fmt"
  "github.com/Luzifer/go-openssl"
)

func main() {
  plaintext := "Hello World!"
  passphrase := "z4yH36a6zerhfE5427ZV"

  o := openssl.New()

  enc, err := o.EncryptString(passphrase, plaintext)
  if err != nil {
    fmt.Printf("An error occurred: %s\n", err)
  }

  fmt.Printf("Encrypted text: %s\n", string(enc))
}

Decrypt

import (
  "fmt"
  "github.com/Luzifer/go-openssl"
)

func main() {
  opensslEncrypted := "U2FsdGVkX19ZM5qQJGe/d5A/4pccgH+arBGTp+QnWPU="
	passphrase := "z4yH36a6zerhfE5427ZV"

	o := openssl.New()

	dec, err := o.DecryptString(passphrase, opensslEncrypted)
	if err != nil {
		fmt.Printf("An error occurred: %s\n", err)
	}

  fmt.Printf("Decrypted text: %s\n", string(dec))
}

Testing

To execute the tests for this library you need to be on a system having /bin/bash and openssl available as the compatibility of the output is tested directly against the openssl binary. The library itself should be usable on all operating systems supported by Go and crypto/aes.