# 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`](https://www.cryptopp.com/wiki/OPENSSL_EVP_BytesToKey). 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

```go
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

```go
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`.