diff options
Diffstat (limited to 'vendor/golang.org/x/crypto/xtea/cipher.go')
-rw-r--r-- | vendor/golang.org/x/crypto/xtea/cipher.go | 82 |
1 files changed, 0 insertions, 82 deletions
diff --git a/vendor/golang.org/x/crypto/xtea/cipher.go b/vendor/golang.org/x/crypto/xtea/cipher.go deleted file mode 100644 index 66ea0df16..000000000 --- a/vendor/golang.org/x/crypto/xtea/cipher.go +++ /dev/null @@ -1,82 +0,0 @@ -// Copyright 2009 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 xtea implements XTEA encryption, as defined in Needham and Wheeler's -// 1997 technical report, "Tea extensions." -package xtea // import "golang.org/x/crypto/xtea" - -// For details, see http://www.cix.co.uk/~klockstone/xtea.pdf - -import "strconv" - -// The XTEA block size in bytes. -const BlockSize = 8 - -// A Cipher is an instance of an XTEA cipher using a particular key. -// table contains a series of precalculated values that are used each round. -type Cipher struct { - table [64]uint32 -} - -type KeySizeError int - -func (k KeySizeError) Error() string { - return "crypto/xtea: invalid key size " + strconv.Itoa(int(k)) -} - -// NewCipher creates and returns a new Cipher. -// The key argument should be the XTEA key. -// XTEA only supports 128 bit (16 byte) keys. -func NewCipher(key []byte) (*Cipher, error) { - k := len(key) - switch k { - default: - return nil, KeySizeError(k) - case 16: - break - } - - c := new(Cipher) - initCipher(c, key) - - return c, nil -} - -// BlockSize returns the XTEA block size, 8 bytes. -// It is necessary to satisfy the Block interface in the -// package "crypto/cipher". -func (c *Cipher) BlockSize() int { return BlockSize } - -// Encrypt encrypts the 8 byte buffer src using the key and stores the result in dst. -// Note that for amounts of data larger than a block, -// it is not safe to just call Encrypt on successive blocks; -// instead, use an encryption mode like CBC (see crypto/cipher/cbc.go). -func (c *Cipher) Encrypt(dst, src []byte) { encryptBlock(c, dst, src) } - -// Decrypt decrypts the 8 byte buffer src using the key k and stores the result in dst. -func (c *Cipher) Decrypt(dst, src []byte) { decryptBlock(c, dst, src) } - -// initCipher initializes the cipher context by creating a look up table -// of precalculated values that are based on the key. -func initCipher(c *Cipher, key []byte) { - // Load the key into four uint32s - var k [4]uint32 - for i := 0; i < len(k); i++ { - j := i << 2 // Multiply by 4 - k[i] = uint32(key[j+0])<<24 | uint32(key[j+1])<<16 | uint32(key[j+2])<<8 | uint32(key[j+3]) - } - - // Precalculate the table - const delta = 0x9E3779B9 - var sum uint32 - - // Two rounds of XTEA applied per loop - for i := 0; i < numRounds; { - c.table[i] = sum + k[sum&3] - i++ - sum += delta - c.table[i] = sum + k[(sum>>11)&3] - i++ - } -} |