1 files changed, 70 insertions, 0 deletions
diff --git a/vendor/github.com/miekg/dns/vendor/golang.org/x/crypto/chacha20poly1305/chacha20poly1305_generic.go b/vendor/github.com/miekg/dns/vendor/golang.org/x/crypto/chacha20poly1305/chacha20poly1305_generic.go
new file mode 100644
index 000000000..f7e4bfb1c
--- /dev/null
+++ b/vendor/github.com/miekg/dns/vendor/golang.org/x/crypto/chacha20poly1305/chacha20poly1305_generic.go
@@ -0,0 +1,70 @@
+// 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
+
+import (
+	"encoding/binary"
+
+	"golang.org/x/crypto/chacha20poly1305/internal/chacha20"
+	"golang.org/x/crypto/poly1305"
+)
+
+func roundTo16(n int) int {
+	return 16 * ((n + 15) / 16)
+}
+
+func (c *chacha20poly1305) sealGeneric(dst, nonce, plaintext, additionalData []byte) []byte {
+	var counter [16]byte
+	copy(counter[4:], nonce)
+
+	var polyKey [32]byte
+	chacha20.XORKeyStream(polyKey[:], polyKey[:], &counter, &c.key)
+
+	ret, out := sliceForAppend(dst, len(plaintext)+poly1305.TagSize)
+	counter[0] = 1
+	chacha20.XORKeyStream(out, plaintext, &counter, &c.key)
+
+	polyInput := make([]byte, roundTo16(len(additionalData))+roundTo16(len(plaintext))+8+8)
+	copy(polyInput, additionalData)
+	copy(polyInput[roundTo16(len(additionalData)):], out[:len(plaintext)])
+	binary.LittleEndian.PutUint64(polyInput[len(polyInput)-16:], uint64(len(additionalData)))
+	binary.LittleEndian.PutUint64(polyInput[len(polyInput)-8:], uint64(len(plaintext)))
+
+	var tag [poly1305.TagSize]byte
+	poly1305.Sum(&tag, polyInput, &polyKey)
+	copy(out[len(plaintext):], tag[:])
+
+	return ret
+}
+
+func (c *chacha20poly1305) openGeneric(dst, nonce, ciphertext, additionalData []byte) ([]byte, error) {
+	var tag [poly1305.TagSize]byte
+	copy(tag[:], ciphertext[len(ciphertext)-16:])
+	ciphertext = ciphertext[:len(ciphertext)-16]
+
+	var counter [16]byte
+	copy(counter[4:], nonce)
+
+	var polyKey [32]byte
+	chacha20.XORKeyStream(polyKey[:], polyKey[:], &counter, &c.key)
+
+	polyInput := make([]byte, roundTo16(len(additionalData))+roundTo16(len(ciphertext))+8+8)
+	copy(polyInput, additionalData)
+	copy(polyInput[roundTo16(len(additionalData)):], ciphertext)
+	binary.LittleEndian.PutUint64(polyInput[len(polyInput)-16:], uint64(len(additionalData)))
+	binary.LittleEndian.PutUint64(polyInput[len(polyInput)-8:], uint64(len(ciphertext)))
+
+	ret, out := sliceForAppend(dst, len(ciphertext))
+	if !poly1305.Verify(&tag, polyInput, &polyKey) {
+		for i := range out {
+			out[i] = 0
+		}
+		return nil, errOpen
+	}
+
+	counter[0] = 1
+	chacha20.XORKeyStream(out, ciphertext, &counter, &c.key)
+	return ret, nil
+}