vendor golang.org/x/crypto using glide

This would help us build go-mtree on RHEL/CentOS and
distros where golang.org/x/crypto isn't provided or supported.

Signed-off-by: Lokesh Mandvekar <lsm5@fedoraproject.org>

vendor/golang.org/x/crypto/nacl/secretbox/example_test.go

@@ -0,0 +1,53 @@
+// 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 secretbox_test
+
+import (
+	"crypto/rand"
+	"encoding/hex"
+	"fmt"
+	"io"
+
+	"golang.org/x/crypto/nacl/secretbox"
+)
+
+func Example() {
+	// Load your secret key from a safe place and reuse it across multiple
+	// Seal calls. (Obviously don't use this example key for anything
+	// real.) If you want to convert a passphrase to a key, use a suitable
+	// package like bcrypt or scrypt.
+	secretKeyBytes, err := hex.DecodeString("6368616e676520746869732070617373776f726420746f206120736563726574")
+	if err != nil {
+		panic(err)
+	}
+
+	var secretKey [32]byte
+	copy(secretKey[:], secretKeyBytes)
+
+	// You must use a different nonce for each message you encrypt with the
+	// same key. Since the nonce here is 192 bits long, a random value
+	// provides a sufficiently small probability of repeats.
+	var nonce [24]byte
+	if _, err := io.ReadFull(rand.Reader, nonce[:]); err != nil {
+		panic(err)
+	}
+
+	// This encrypts "hello world" and appends the result to the nonce.
+	encrypted := secretbox.Seal(nonce[:], []byte("hello world"), &nonce, &secretKey)
+
+	// When you decrypt, you must use the same nonce and key you used to
+	// encrypt the message. One way to achieve this is to store the nonce
+	// alongside the encrypted message. Above, we stored the nonce in the first
+	// 24 bytes of the encrypted text.
+	var decryptNonce [24]byte
+	copy(decryptNonce[:], encrypted[:24])
+	decrypted, ok := secretbox.Open([]byte{}, encrypted[24:], &decryptNonce, &secretKey)
+	if !ok {
+		panic("decryption error")
+	}
+
+	fmt.Println(string(decrypted))
+	// Output: hello world
+}

vendor/golang.org/x/crypto/nacl/secretbox/secretbox.go

@@ -0,0 +1,149 @@
+// 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 secretbox encrypts and authenticates small messages.
+
+Secretbox uses XSalsa20 and Poly1305 to encrypt and authenticate messages with
+secret-key cryptography. 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.
+
+This package is interoperable with NaCl: https://nacl.cr.yp.to/secretbox.html.
+*/
+package secretbox // import "golang.org/x/crypto/nacl/secretbox"
+
+import (
+	"golang.org/x/crypto/poly1305"
+	"golang.org/x/crypto/salsa20/salsa"
+)
+
+// Overhead is the number of bytes of overhead when boxing a message.
+const Overhead = poly1305.TagSize
+
+// setup produces a sub-key and Salsa20 counter given a nonce and key.
+func setup(subKey *[32]byte, counter *[16]byte, nonce *[24]byte, key *[32]byte) {
+	// We use XSalsa20 for encryption so first we need to generate a
+	// key and nonce with HSalsa20.
+	var hNonce [16]byte
+	copy(hNonce[:], nonce[:])
+	salsa.HSalsa20(subKey, &hNonce, key, &salsa.Sigma)
+
+	// The final 8 bytes of the original nonce form the new nonce.
+	copy(counter[:], nonce[16:])
+}
+
+// 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
+}
+
+// Seal appends an encrypted and authenticated copy of message to out, which
+// must not overlap message. The key and nonce pair must be unique for each
+// distinct message and the output will be Overhead bytes longer than message.
+func Seal(out, message []byte, nonce *[24]byte, key *[32]byte) []byte {
+	var subKey [32]byte
+	var counter [16]byte
+	setup(&subKey, &counter, nonce, key)
+
+	// The Poly1305 key is generated by encrypting 32 bytes of zeros. Since
+	// Salsa20 works with 64-byte blocks, we also generate 32 bytes of
+	// keystream as a side effect.
+	var firstBlock [64]byte
+	salsa.XORKeyStream(firstBlock[:], firstBlock[:], &counter, &subKey)
+
+	var poly1305Key [32]byte
+	copy(poly1305Key[:], firstBlock[:])
+
+	ret, out := sliceForAppend(out, len(message)+poly1305.TagSize)
+
+	// We XOR up to 32 bytes of message with the keystream generated from
+	// the first block.
+	firstMessageBlock := message
+	if len(firstMessageBlock) > 32 {
+		firstMessageBlock = firstMessageBlock[:32]
+	}
+
+	tagOut := out
+	out = out[poly1305.TagSize:]
+	for i, x := range firstMessageBlock {
+		out[i] = firstBlock[32+i] ^ x
+	}
+	message = message[len(firstMessageBlock):]
+	ciphertext := out
+	out = out[len(firstMessageBlock):]
+
+	// Now encrypt the rest.
+	counter[8] = 1
+	salsa.XORKeyStream(out, message, &counter, &subKey)
+
+	var tag [poly1305.TagSize]byte
+	poly1305.Sum(&tag, ciphertext, &poly1305Key)
+	copy(tagOut, tag[:])
+
+	return ret
+}
+
+// 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 []byte, box []byte, nonce *[24]byte, key *[32]byte) ([]byte, bool) {
+	if len(box) < Overhead {
+		return nil, false
+	}
+
+	var subKey [32]byte
+	var counter [16]byte
+	setup(&subKey, &counter, nonce, key)
+
+	// The Poly1305 key is generated by encrypting 32 bytes of zeros. Since
+	// Salsa20 works with 64-byte blocks, we also generate 32 bytes of
+	// keystream as a side effect.
+	var firstBlock [64]byte
+	salsa.XORKeyStream(firstBlock[:], firstBlock[:], &counter, &subKey)
+
+	var poly1305Key [32]byte
+	copy(poly1305Key[:], firstBlock[:])
+	var tag [poly1305.TagSize]byte
+	copy(tag[:], box)
+
+	if !poly1305.Verify(&tag, box[poly1305.TagSize:], &poly1305Key) {
+		return nil, false
+	}
+
+	ret, out := sliceForAppend(out, len(box)-Overhead)
+
+	// We XOR up to 32 bytes of box with the keystream generated from
+	// the first block.
+	box = box[Overhead:]
+	firstMessageBlock := box
+	if len(firstMessageBlock) > 32 {
+		firstMessageBlock = firstMessageBlock[:32]
+	}
+	for i, x := range firstMessageBlock {
+		out[i] = firstBlock[32+i] ^ x
+	}
+
+	box = box[len(firstMessageBlock):]
+	out = out[len(firstMessageBlock):]
+
+	// Now decrypt the rest.
+	counter[8] = 1
+	salsa.XORKeyStream(out, box, &counter, &subKey)
+
+	return ret, true
+}

vendor/golang.org/x/crypto/nacl/secretbox/secretbox_test.go

@@ -0,0 +1,91 @@
+// 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 secretbox
+
+import (
+	"bytes"
+	"crypto/rand"
+	"encoding/hex"
+	"testing"
+)
+
+func TestSealOpen(t *testing.T) {
+	var key [32]byte
+	var nonce [24]byte
+
+	rand.Reader.Read(key[:])
+	rand.Reader.Read(nonce[:])
+
+	var box, opened []byte
+
+	for msgLen := 0; msgLen < 128; msgLen += 17 {
+		message := make([]byte, msgLen)
+		rand.Reader.Read(message)
+
+		box = Seal(box[:0], message, &nonce, &key)
+		var ok bool
+		opened, ok = Open(opened[:0], box, &nonce, &key)
+		if !ok {
+			t.Errorf("%d: failed to open box", msgLen)
+			continue
+		}
+
+		if !bytes.Equal(opened, message) {
+			t.Errorf("%d: got %x, expected %x", msgLen, opened, message)
+			continue
+		}
+	}
+
+	for i := range box {
+		box[i] ^= 0x20
+		_, ok := Open(opened[:0], box, &nonce, &key)
+		if ok {
+			t.Errorf("box was opened after corrupting byte %d", i)
+		}
+		box[i] ^= 0x20
+	}
+}
+
+func TestSecretBox(t *testing.T) {
+	var key [32]byte
+	var nonce [24]byte
+	var message [64]byte
+
+	for i := range key[:] {
+		key[i] = 1
+	}
+	for i := range nonce[:] {
+		nonce[i] = 2
+	}
+	for i := range message[:] {
+		message[i] = 3
+	}
+
+	box := Seal(nil, message[:], &nonce, &key)
+	// expected was generated using the C implementation of NaCl.
+	expected, _ := hex.DecodeString("8442bc313f4626f1359e3b50122b6ce6fe66ddfe7d39d14e637eb4fd5b45beadab55198df6ab5368439792a23c87db70acb6156dc5ef957ac04f6276cf6093b84be77ff0849cc33e34b7254d5a8f65ad")
+
+	if !bytes.Equal(box, expected) {
+		t.Fatalf("box didn't match, got\n%x\n, expected\n%x", box, expected)
+	}
+}
+
+func TestAppend(t *testing.T) {
+	var key [32]byte
+	var nonce [24]byte
+	var message [8]byte
+
+	out := make([]byte, 4)
+	box := Seal(out, message[:], &nonce, &key)
+	if !bytes.Equal(box[:4], out[:4]) {
+		t.Fatalf("Seal didn't correctly append")
+	}
+
+	out = make([]byte, 4, 100)
+	box = Seal(out, message[:], &nonce, &key)
+	if !bytes.Equal(box[:4], out[:4]) {
+		t.Fatalf("Seal didn't correctly append with sufficient capacity.")
+	}
+}