1 files changed, 83 insertions, 0 deletions
diff --git a/vendor/golang.org/x/crypto/chacha20poly1305/chacha20poly1305.go b/vendor/golang.org/x/crypto/chacha20poly1305/chacha20poly1305.go
new file mode 100644
index 0000000..3f0dcb9
--- /dev/null
+++ b/vendor/golang.org/x/crypto/chacha20poly1305/chacha20poly1305.go
@@ -0,0 +1,83 @@
+// Copyright 2016 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 chacha20poly1305 implements the ChaCha20-Poly1305 AEAD as specified in RFC 7539.
+package chacha20poly1305 // import "golang.org/x/crypto/chacha20poly1305"
+
+import (
+	"crypto/cipher"
+	"errors"
+)
+
+const (
+	// KeySize is the size of the key used by this AEAD, in bytes.
+	KeySize = 32
+	// NonceSize is the size of the nonce used with this AEAD, in bytes.
+	NonceSize = 12
+)
+
+type chacha20poly1305 struct {
+	key [32]byte
+}
+
+// New returns a ChaCha20-Poly1305 AEAD that uses the given, 256-bit key.
+func New(key []byte) (cipher.AEAD, error) {
+	if len(key) != KeySize {
+		return nil, errors.New("chacha20poly1305: bad key length")
+	}
+	ret := new(chacha20poly1305)
+	copy(ret.key[:], key)
+	return ret, nil
+}
+
+func (c *chacha20poly1305) NonceSize() int {
+	return NonceSize
+}
+
+func (c *chacha20poly1305) Overhead() int {
+	return 16
+}
+
+func (c *chacha20poly1305) Seal(dst, nonce, plaintext, additionalData []byte) []byte {
+	if len(nonce) != NonceSize {
+		panic("chacha20poly1305: bad nonce length passed to Seal")
+	}
+
+	if uint64(len(plaintext)) > (1<<38)-64 {
+		panic("chacha20poly1305: plaintext too large")
+	}
+
+	return c.seal(dst, nonce, plaintext, additionalData)
+}
+
+var errOpen = errors.New("chacha20poly1305: message authentication failed")
+
+func (c *chacha20poly1305) Open(dst, nonce, ciphertext, additionalData []byte) ([]byte, error) {
+	if len(nonce) != NonceSize {
+		panic("chacha20poly1305: bad nonce length passed to Open")
+	}
+	if len(ciphertext) < 16 {
+		return nil, errOpen
+	}
+	if uint64(len(ciphertext)) > (1<<38)-48 {
+		panic("chacha20poly1305: ciphertext too large")
+	}
+
+	return c.open(dst, nonce, ciphertext, additionalData)
+}
+
+// sliceForAppend takes a slice and a requested number of bytes. It returns a
+// slice with the contents of the given slice followed by that many bytes and a
+// second slice that aliases into it and contains only the extra bytes. If the
+// original slice has sufficient capacity then no allocation is performed.
+func sliceForAppend(in []byte, n int) (head, tail []byte) {
+	if total := len(in) + n; cap(in) >= total {
+		head = in[:total]
+	} else {
+		head = make([]byte, total)
+		copy(head, in)
+	}
+	tail = head[len(in):]
+	return
+}