safing-jess/tools/gostdlib/chacha20-poly1305.go
2020-01-13 00:15:58 +01:00

81 lines
2.1 KiB
Go

package gostdlib
import (
"crypto/cipher"
"github.com/safing/jess/tools"
"golang.org/x/crypto/chacha20poly1305"
)
func init() {
tools.Register(&tools.Tool{
Info: &tools.ToolInfo{
Name: "CHACHA20-POLY1305",
Purpose: tools.PurposeIntegratedCipher,
Options: []uint8{tools.OptionHasState},
KeySize: chacha20poly1305.KeySize, // 256 bit
NonceSize: chacha20poly1305.NonceSize,
SecurityLevel: 128, // ChaCha20 is actually 256. Limiting to 128 for now because of Poly1305. TODO: do some more research on Poly1305
Comment: "RFC 7539",
Author: "Daniel J. Bernstein, 2008 and 2005",
},
Factory: func() tools.ToolLogic { return &ChaCha20Poly1305{} },
})
}
// ChaCha20Poly1305 implements the cryptographic interface for ChaCha20-Poly1305 encryption.
type ChaCha20Poly1305 struct {
tools.ToolLogicBase
aead cipher.AEAD
key, nonce []byte
}
// Setup implements the ToolLogic interface.
func (chapo *ChaCha20Poly1305) Setup() (err error) {
// get key
chapo.key, err = chapo.Helper().NewSessionKey()
if err != nil {
return err
}
// get nonce
chapo.nonce, err = chapo.Helper().NewSessionNonce()
if err != nil {
return err
}
// get aead interface
chapo.aead, err = chacha20poly1305.New(chapo.key)
if err != nil {
return err
}
return nil
}
// Reset implements the ToolLogic interface.
func (chapo *ChaCha20Poly1305) Reset() error {
// clean up keys
chapo.Helper().Burn(chapo.key)
chapo.Helper().Burn(chapo.nonce)
return nil
}
// AuthenticatedEncrypt implements the ToolLogic interface.
func (chapo *ChaCha20Poly1305) AuthenticatedEncrypt(data, associatedData []byte) ([]byte, error) {
// encrypt and authenticate
data = chapo.aead.Seal(data[:0], chapo.nonce, data, associatedData)
return data, nil
}
// AuthenticatedDecrypt implements the ToolLogic interface.
func (chapo *ChaCha20Poly1305) AuthenticatedDecrypt(data, associatedData []byte) ([]byte, error) {
// decrypt and authenticate
var err error
data, err = chapo.aead.Open(data[:0], chapo.nonce, data, associatedData)
return data, err
}