Public Release

noise.go

@@ -0,0 +1,60 @@
+package nebula
+
+import (
+	"crypto/cipher"
+	"encoding/binary"
+	"errors"
+
+	"github.com/flynn/noise"
+)
+
+type endiannes interface {
+	PutUint64(b []byte, v uint64)
+}
+
+var noiseEndiannes endiannes = binary.BigEndian
+
+type NebulaCipherState struct {
+	c noise.Cipher
+	//k [32]byte
+	//n uint64
+}
+
+func NewNebulaCipherState(s *noise.CipherState) *NebulaCipherState {
+	return &NebulaCipherState{c: s.Cipher()}
+
+}
+
+func (s *NebulaCipherState) EncryptDanger(out, ad, plaintext []byte, n uint64, nb []byte) ([]byte, error) {
+	if s != nil {
+		// TODO: Is this okay now that we have made messageCounter atomic?
+		// Alternative may be to split the counter space into ranges
+		//if n <= s.n {
+		//	return nil, errors.New("CRITICAL: a duplicate counter value was used")
+		//}
+		//s.n = n
+		nb[0] = 0
+		nb[1] = 0
+		nb[2] = 0
+		nb[3] = 0
+		noiseEndiannes.PutUint64(nb[4:], n)
+		out = s.c.(cipher.AEAD).Seal(out, nb, plaintext, ad)
+		//l.Debugf("Encryption: outlen: %d, nonce: %d, ad: %s, plainlen %d", len(out), n, ad, len(plaintext))
+		return out, nil
+	} else {
+		return nil, errors.New("no cipher state available to encrypt")
+	}
+}
+
+func (s *NebulaCipherState) DecryptDanger(out, ad, ciphertext []byte, n uint64, nb []byte) ([]byte, error) {
+	if s != nil {
+		nb[0] = 0
+		nb[1] = 0
+		nb[2] = 0
+		nb[3] = 0
+		noiseEndiannes.PutUint64(nb[4:], n)
+		return s.c.(cipher.AEAD).Open(out, nb, ciphertext, ad)
+	} else {
+		return []byte{}, nil
+	}
+}