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author | Christopher Speller <crspeller@gmail.com> | 2018-04-16 05:37:14 -0700 |
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committer | Joram Wilander <jwawilander@gmail.com> | 2018-04-16 08:37:14 -0400 |
commit | 6e2cb00008cbf09e556b00f87603797fcaa47e09 (patch) | |
tree | 3c0eb55ff4226a3f024aad373140d1fb860a6404 /vendor/golang.org/x/crypto/nacl/secretbox/secretbox.go | |
parent | bf24f51c4e1cc6286885460672f7f449e8c6f5ef (diff) | |
download | chat-6e2cb00008cbf09e556b00f87603797fcaa47e09.tar.gz chat-6e2cb00008cbf09e556b00f87603797fcaa47e09.tar.bz2 chat-6e2cb00008cbf09e556b00f87603797fcaa47e09.zip |
Depenancy upgrades and movign to dep. (#8630)
Diffstat (limited to 'vendor/golang.org/x/crypto/nacl/secretbox/secretbox.go')
-rw-r--r-- | vendor/golang.org/x/crypto/nacl/secretbox/secretbox.go | 166 |
1 files changed, 0 insertions, 166 deletions
diff --git a/vendor/golang.org/x/crypto/nacl/secretbox/secretbox.go b/vendor/golang.org/x/crypto/nacl/secretbox/secretbox.go deleted file mode 100644 index 53ee83cfb..000000000 --- a/vendor/golang.org/x/crypto/nacl/secretbox/secretbox.go +++ /dev/null @@ -1,166 +0,0 @@ -// 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 -} |