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Diffstat (limited to 'vendor/golang.org/x/crypto/nacl/secretbox')
3 files changed, 373 insertions, 0 deletions
diff --git a/vendor/golang.org/x/crypto/nacl/secretbox/example_test.go b/vendor/golang.org/x/crypto/nacl/secretbox/example_test.go new file mode 100644 index 0000000..789f4ff --- /dev/null +++ b/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(nil, encrypted[24:], &decryptNonce, &secretKey) + if !ok { + panic("decryption error") + } + + fmt.Println(string(decrypted)) + // Output: hello world +} diff --git a/vendor/golang.org/x/crypto/nacl/secretbox/secretbox.go b/vendor/golang.org/x/crypto/nacl/secretbox/secretbox.go new file mode 100644 index 0000000..53ee83c --- /dev/null +++ b/vendor/golang.org/x/crypto/nacl/secretbox/secretbox.go @@ -0,0 +1,166 @@ +// 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. + +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/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 +} diff --git a/vendor/golang.org/x/crypto/nacl/secretbox/secretbox_test.go b/vendor/golang.org/x/crypto/nacl/secretbox/secretbox_test.go new file mode 100644 index 0000000..3c70b0f --- /dev/null +++ b/vendor/golang.org/x/crypto/nacl/secretbox/secretbox_test.go @@ -0,0 +1,154 @@ +// 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.") + } +} + +func benchmarkSealSize(b *testing.B, size int) { + message := make([]byte, size) + out := make([]byte, size+Overhead) + var nonce [24]byte + var key [32]byte + + b.SetBytes(int64(size)) + b.ResetTimer() + + for i := 0; i < b.N; i++ { + out = Seal(out[:0], message, &nonce, &key) + } +} + +func BenchmarkSeal8Bytes(b *testing.B) { + benchmarkSealSize(b, 8) +} + +func BenchmarkSeal100Bytes(b *testing.B) { + benchmarkSealSize(b, 100) +} + +func BenchmarkSeal1K(b *testing.B) { + benchmarkSealSize(b, 1024) +} + +func BenchmarkSeal8K(b *testing.B) { + benchmarkSealSize(b, 8192) +} + +func benchmarkOpenSize(b *testing.B, size int) { + msg := make([]byte, size) + result := make([]byte, size) + var nonce [24]byte + var key [32]byte + box := Seal(nil, msg, &nonce, &key) + + b.SetBytes(int64(size)) + b.ResetTimer() + + for i := 0; i < b.N; i++ { + if _, ok := Open(result[:0], box, &nonce, &key); !ok { + panic("Open failed") + } + } +} + +func BenchmarkOpen8Bytes(b *testing.B) { + benchmarkOpenSize(b, 8) +} + +func BenchmarkOpen100Bytes(b *testing.B) { + benchmarkOpenSize(b, 100) +} + +func BenchmarkOpen1K(b *testing.B) { + benchmarkOpenSize(b, 1024) +} + +func BenchmarkOpen8K(b *testing.B) { + benchmarkOpenSize(b, 8192) +} |