diff options
Diffstat (limited to 'vendor/golang.org/x/crypto/nacl/box')
-rw-r--r-- | vendor/golang.org/x/crypto/nacl/box/box.go | 85 | ||||
-rw-r--r-- | vendor/golang.org/x/crypto/nacl/box/box_test.go | 78 |
2 files changed, 163 insertions, 0 deletions
diff --git a/vendor/golang.org/x/crypto/nacl/box/box.go b/vendor/golang.org/x/crypto/nacl/box/box.go new file mode 100644 index 000000000..ca48a6dbf --- /dev/null +++ b/vendor/golang.org/x/crypto/nacl/box/box.go @@ -0,0 +1,85 @@ +// 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 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. + +This package is interoperable with NaCl: http://nacl.cr.yp.to/box.html. +*/ +package box // import "golang.org/x/crypto/nacl/box" + +import ( + "golang.org/x/crypto/curve25519" + "golang.org/x/crypto/nacl/secretbox" + "golang.org/x/crypto/salsa20/salsa" + "io" +) + +// 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. 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) +} diff --git a/vendor/golang.org/x/crypto/nacl/box/box_test.go b/vendor/golang.org/x/crypto/nacl/box/box_test.go new file mode 100644 index 000000000..481ade28a --- /dev/null +++ b/vendor/golang.org/x/crypto/nacl/box/box_test.go @@ -0,0 +1,78 @@ +// 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 + +import ( + "bytes" + "crypto/rand" + "encoding/hex" + "testing" + + "golang.org/x/crypto/curve25519" +) + +func TestSealOpen(t *testing.T) { + publicKey1, privateKey1, _ := GenerateKey(rand.Reader) + publicKey2, privateKey2, _ := GenerateKey(rand.Reader) + + if *privateKey1 == *privateKey2 { + t.Fatalf("private keys are equal!") + } + if *publicKey1 == *publicKey2 { + t.Fatalf("public keys are equal!") + } + message := []byte("test message") + var nonce [24]byte + + box := Seal(nil, message, &nonce, publicKey1, privateKey2) + opened, ok := Open(nil, box, &nonce, publicKey2, privateKey1) + if !ok { + t.Fatalf("failed to open box") + } + + if !bytes.Equal(opened, message) { + t.Fatalf("got %x, want %x", opened, message) + } + + for i := range box { + box[i] ^= 0x40 + _, ok := Open(nil, box, &nonce, publicKey2, privateKey1) + if ok { + t.Fatalf("opened box with byte %d corrupted", i) + } + box[i] ^= 0x40 + } +} + +func TestBox(t *testing.T) { + var privateKey1, privateKey2 [32]byte + for i := range privateKey1[:] { + privateKey1[i] = 1 + } + for i := range privateKey2[:] { + privateKey2[i] = 2 + } + + var publicKey1 [32]byte + curve25519.ScalarBaseMult(&publicKey1, &privateKey1) + var message [64]byte + for i := range message[:] { + message[i] = 3 + } + + var nonce [24]byte + for i := range nonce[:] { + nonce[i] = 4 + } + + box := Seal(nil, message[:], &nonce, &publicKey1, &privateKey2) + + // expected was generated using the C implementation of NaCl. + expected, _ := hex.DecodeString("78ea30b19d2341ebbdba54180f821eec265cf86312549bea8a37652a8bb94f07b78a73ed1708085e6ddd0e943bbdeb8755079a37eb31d86163ce241164a47629c0539f330b4914cd135b3855bc2a2dfc") + + if !bytes.Equal(box, expected) { + t.Fatalf("box didn't match, got\n%x\n, expected\n%x", box, expected) + } +} |