Initial QSfera import

Server/vendor/github.com/libregraph/lico/encryption/encryption.go

@@ -0,0 +1,64 @@
+/*
+ * Copyright 2017-2019 Kopano and its licensors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+package encryption
+
+import (
+	"fmt"
+
+	"golang.org/x/crypto/nacl/secretbox"
+)
+
+const (
+	// KeySize is the size of the keys created by GenerateKey()
+	KeySize = 32
+	// NonceSize is the size of the nonces created by GenerateNonce()
+	NonceSize = 24
+)
+
+// Encrypt generates a random nonce and encrypts the input using nacl.secretbox
+// package. We store the nonce in the first 24 bytes of the encrypted text.
+func Encrypt(msg []byte, key *[KeySize]byte) ([]byte, error) {
+	nonce, err := GenerateNonce()
+	if err != nil {
+		return nil, err
+	}
+
+	return encryptWithNonce(msg, nonce, key)
+}
+
+func encryptWithNonce(msg []byte, nonce *[NonceSize]byte, key *[KeySize]byte) ([]byte, error) {
+	encrypted := secretbox.Seal(nonce[:], msg, nonce, key)
+	return encrypted, nil
+}
+
+// Decrypt extracts the nonce from the encrypted text, and attempts to decrypt
+// with nacl.box.
+func Decrypt(msg []byte, key *[KeySize]byte) ([]byte, error) {
+	if len(msg) < (NonceSize + secretbox.Overhead) {
+		return nil, fmt.Errorf("wrong length of ciphertext")
+	}
+
+	var nonce [NonceSize]byte
+	copy(nonce[:], msg[:NonceSize])
+	decrypted, ok := secretbox.Open(nil, msg[NonceSize:], &nonce, key)
+	if !ok {
+		return nil, fmt.Errorf("decryption failed")
+	}
+
+	return decrypted, nil
+}