1 files changed, 103 insertions, 0 deletions
diff --git a/vendor/github.com/miekg/dns/vendor/golang.org/x/crypto/nacl/box/box.go b/vendor/github.com/miekg/dns/vendor/golang.org/x/crypto/nacl/box/box.go
new file mode 100644
index 000000000..31b697be4
--- /dev/null
+++ b/vendor/github.com/miekg/dns/vendor/golang.org/x/crypto/nacl/box/box.go
@@ -0,0 +1,103 @@
+// Copyright 2012 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+/*
+Package box authenticates and encrypts small messages using public-key cryptography.
+
+Box uses Curve25519, XSalsa20 and Poly1305 to encrypt and authenticate
+messages. The length of messages is not hidden.
+
+It is the caller's responsibility to ensure the uniqueness of nonces—for
+example, by using nonce 1 for the first message, nonce 2 for the second
+message, etc. Nonces are long enough that randomly generated nonces have
+negligible risk of collision.
+
+Messages should be small because:
+
+1. The whole message needs to be held in memory to be processed.
+
+2. Using large messages pressures implementations on small machines to decrypt
+and process plaintext before authenticating it. This is very dangerous, and
+this API does not allow it, but a protocol that uses excessive message sizes
+might present some implementations with no other choice.
+
+3. Fixed overheads will be sufficiently amortised by messages as small as 8KB.
+
+4. Performance may be improved by working with messages that fit into data caches.
+
+Thus large amounts of data should be chunked so that each message is small.
+(Each message still needs a unique nonce.) If in doubt, 16KB is a reasonable
+chunk size.
+
+This package is interoperable with NaCl: https://nacl.cr.yp.to/box.html.
+*/
+package box // import "golang.org/x/crypto/nacl/box"
+
+import (
+	"io"
+
+	"golang.org/x/crypto/curve25519"
+	"golang.org/x/crypto/nacl/secretbox"
+	"golang.org/x/crypto/salsa20/salsa"
+)
+
+// Overhead is the number of bytes of overhead when boxing a message.
+const Overhead = secretbox.Overhead
+
+// GenerateKey generates a new public/private key pair suitable for use with
+// Seal and Open.
+func GenerateKey(rand io.Reader) (publicKey, privateKey *[32]byte, err error) {
+	publicKey = new([32]byte)
+	privateKey = new([32]byte)
+	_, err = io.ReadFull(rand, privateKey[:])
+	if err != nil {
+		publicKey = nil
+		privateKey = nil
+		return
+	}
+
+	curve25519.ScalarBaseMult(publicKey, privateKey)
+	return
+}
+
+var zeros [16]byte
+
+// Precompute calculates the shared key between peersPublicKey and privateKey
+// and writes it to sharedKey. The shared key can be used with
+// OpenAfterPrecomputation and SealAfterPrecomputation to speed up processing
+// when using the same pair of keys repeatedly.
+func Precompute(sharedKey, peersPublicKey, privateKey *[32]byte) {
+	curve25519.ScalarMult(sharedKey, privateKey, peersPublicKey)
+	salsa.HSalsa20(sharedKey, &zeros, sharedKey, &salsa.Sigma)
+}
+
+// Seal appends an encrypted and authenticated copy of message to out, which
+// will be Overhead bytes longer than the original and must not overlap it. The
+// nonce must be unique for each distinct message for a given pair of keys.
+func Seal(out, message []byte, nonce *[24]byte, peersPublicKey, privateKey *[32]byte) []byte {
+	var sharedKey [32]byte
+	Precompute(&sharedKey, peersPublicKey, privateKey)
+	return secretbox.Seal(out, message, nonce, &sharedKey)
+}
+
+// SealAfterPrecomputation performs the same actions as Seal, but takes a
+// shared key as generated by Precompute.
+func SealAfterPrecomputation(out, message []byte, nonce *[24]byte, sharedKey *[32]byte) []byte {
+	return secretbox.Seal(out, message, nonce, sharedKey)
+}
+
+// Open authenticates and decrypts a box produced by Seal and appends the
+// message to out, which must not overlap box. The output will be Overhead
+// bytes smaller than box.
+func Open(out, box []byte, nonce *[24]byte, peersPublicKey, privateKey *[32]byte) ([]byte, bool) {
+	var sharedKey [32]byte
+	Precompute(&sharedKey, peersPublicKey, privateKey)
+	return secretbox.Open(out, box, nonce, &sharedKey)
+}
+
+// OpenAfterPrecomputation performs the same actions as Open, but takes a
+// shared key as generated by Precompute.
+func OpenAfterPrecomputation(out, box []byte, nonce *[24]byte, sharedKey *[32]byte) ([]byte, bool) {
+	return secretbox.Open(out, box, nonce, sharedKey)
+}