| Server IP : 84.32.84.64 / Your IP : 216.73.217.6 Web Server : LiteSpeed System : Linux id-dci-web1986.main-hosting.eu 5.14.0-611.26.1.el9_7.x86_64 #1 SMP PREEMPT_DYNAMIC Thu Jan 29 05:24:47 EST 2026 x86_64 User : u686484674 ( 686484674) PHP Version : 8.0.30 Disable Function : system, exec, shell_exec, passthru, mysql_list_dbs, ini_alter, dl, symlink, link, chgrp, leak, popen, apache_child_terminate, virtual, mb_send_mail MySQL : OFF | cURL : ON | WGET : ON | Perl : OFF | Python : OFF | Sudo : OFF | Pkexec : OFF Directory : /proc/self/root/opt/go/pkg/mod/golang.org/x/crypto@v0.31.0/xtea/ |
Upload File : |
// 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."
//
// XTEA is a legacy cipher and its short block size makes it vulnerable to
// birthday bound attacks (see https://sweet32.info). It should only be used
// where compatibility with legacy systems, not security, is the goal.
//
// Deprecated: any new system should use AES (from crypto/aes, if necessary in
// an AEAD mode like crypto/cipher.NewGCM) or XChaCha20-Poly1305 (from
// golang.org/x/crypto/chacha20poly1305).
package 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.
type Cipher struct {
// table contains a series of precalculated values that are used each round.
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 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++
}
}