// Encrypt encrypt something with mcrypt rijndael-256 PHP-style
func Encrypt(key []byte, iv []byte, data []byte) ([]byte, error) {
// keep track of the size of the input data
length := C.int(len(data))
if length == 0 {
return nil, errors.New("Invalid data size of 0")
}
// keep track of any errors that occur on encryption
err := C.int(0)
// encrypt the data
encryptedData := C.encrypt(unsafe.Pointer(&key[0]), C.int(len(key)), unsafe.Pointer(&iv[0]), C.int(len(iv)), (*C.char)(unsafe.Pointer(&data[0])), (*C.int)(unsafe.Pointer(&length)), (*C.int)(unsafe.Pointer(&err)))
// if err is not 0, there is an error
if int(err) != 0 {
return nil, errors.New(C.GoString(C.getError(err)))
}
// ensure that memory is freed on the encrypted data after it is converted to Go bytes
defer C.free(unsafe.Pointer(encryptedData))
// return the Go bytes of the encrypted data
return C.GoBytes(unsafe.Pointer(encryptedData), length), nil
}
func (sc *SecureCell) Protect(data []byte, context []byte) ([]byte, []byte, error) {
if (sc.mode < CELL_MODE_SEAL) || (sc.mode > CELL_MODE_CONTEXT_IMPRINT) {
return nil, nil, errors.New("Invalid mode specified")
}
if nil == sc.key {
return nil, nil, errors.New("Master key was not provided")
}
if nil == data {
return nil, nil, errors.New("Data was not provided")
}
if CELL_MODE_CONTEXT_IMPRINT == sc.mode {
if nil == context {
return nil, nil, errors.New("Context is mandatory for context imprint mode")
}
}
var ctx unsafe.Pointer
var ctxLen C.size_t
if nil != context {
ctx = unsafe.Pointer(&context[0])
ctxLen = C.size_t(len(context))
}
var encLen, addLen C.size_t
if !bool(C.get_protect_size(unsafe.Pointer(&sc.key[0]),
C.size_t(len(sc.key)),
unsafe.Pointer(&data[0]),
C.size_t(len(data)),
ctx,
ctxLen,
C.int(sc.mode),
&encLen,
&addLen)) {
return nil, nil, errors.New("Failed to get ouput size")
}
var addData []byte
var add unsafe.Pointer
encData := make([]byte, encLen, encLen)
if addLen > 0 {
addData = make([]byte, addLen, addLen)
add = unsafe.Pointer(&addData[0])
}
if !bool(C.encrypt(unsafe.Pointer(&sc.key[0]),
C.size_t(len(sc.key)),
unsafe.Pointer(&data[0]),
C.size_t(len(data)),
ctx,
ctxLen,
C.int(sc.mode),
unsafe.Pointer(&encData[0]),
encLen,
add,
addLen)) {
return nil, nil, errors.New("Failed to protect data")
}
return encData, addData, nil
}
