1.前言
AES（ Advanced Encryption Standard ）高級加密標準，又稱 Rijndael加密法，它是由 美國國家標準與技術研究院 （NIST）于2001年11月26日發布于FIPS PUB 197，并在2002年5月26日成為有效的標準 ， 該演算法由比利時密碼學家Joan Daemen和Vincent Rijmen所設計，結合兩位作者的名字 而命名，AES標準支持固定分組128位，密鑰長度可以是128位、192位、256位，
2.作業模式
我們知道，對明文進行加密的程序中，如果明文超過了分組大小，那么就需要進行切割處理，而AES提供給我們多種作業模式，分別是：ECB(電子密碼本)、CBC(密文分組鏈接)、CFB（密文反饋）、OFB（輸出反饋）、CTR（計數器），而我們今天只針對128位的明文進行加密解密處理，分組作業模式不在我們今天討論的范疇，
3.介紹
3.1 狀態矩陣
AES演算法中的狀態矩陣是垂直排列的，如下圖所示，
明文第一步需要轉換成狀態矩陣，而初始密鑰在進行擴展密鑰之前也需要轉化成狀態矩陣，在對密文進行解密時，最后需要將狀態矩陣還原為明文矩陣，
3.2 密鑰擴展
密鑰擴展會生成44組4個位元組的輪密鑰，每16個位元組為1輪密鑰，在進行輪密鑰加的時候，需要將處理過的明文狀態矩陣根據每輪的密鑰進行加密處理，下面我們來看一個例子，假如初始密鑰16位為： abcdefghijklmnop ,那么它的初始輪密鑰如下所示：
3.3 位元組替換
位元組替換，是利用AES提供的S盒來進行替換的，其中高4位代表行數，而低4位則代表列數，在解密時，也用相同的規則在S逆盒中進行替換還原，
3.4 行移位
行移位第0行無需移動，第i行則向左回圈移動i次，解密時則向右回圈移動i次，下面時一個例子：
3.5列混合
列混合的操作是基于有限域伽羅華域的計算，詳情請參考：https://www.cnblogs.com/pitmanhuang/p/16175550.html
在進行列混合操作時，將狀態矩陣與固定的常量矩陣進行有限域的乘積，將結果異或得出列混合后的值，其中加密和解密的常量值陣列是不同的，它們分別為:
4.代碼示例
/**
* 伽羅華域乘積
* @param $a
* @param int $b
* @return int|mixed
*/
function aes_multi($a, $b = 0)
{
if ($a >= 2 ** 8 || 2 ** 8 <= $b) {
exit('只支持GF(2^8)域的計算');
}
$binMulti = [];
$result = 0;
for ($i = 0; $i < 8; $i++) {
$a = ($a & 0x100) ? (($a & 0xFF) ^ 0x1B) : $a;
$binMulti[] = $a;
$a = $a << 1;
}
$binString = str_pad(base_convert($b, 10, 2), 8, 0, STR_PAD_LEFT);
for ($i = 0; $i < 8; $i++) {
if ($binString{$i} === '1') {
$pos = strlen(substr($binString, $i)) - 1;
$result ^= $binMulti[$pos];
}
}
return $result;
}
$rcon = [
0x01000000, 0x02000000, 0x04000000, 0x08000000, 0x10000000,
0x20000000, 0x40000000, 0x80000000, 0x1B000000, 0x36000000];
$constArray = [0x02, 0x03, 0x01, 0x01, 0x01, 0x02, 0x03, 0x01, 0x01, 0x01, 0x02, 0x03, 0x03, 0x01, 0x01, 0x02];
$constArrayReverse = [0x0E, 0x0B, 0x0D, 0x09, 0x09, 0x0E, 0x0B, 0x0D, 0x0D, 0x09, 0x0E, 0x0B, 0x0B, 0x0D, 0x09, 0x0E];
//S盒
$s = [
0x63, 0x7C, 0x77, 0x7B, 0xF2, 0x6B, 0x6F, 0xC5, 0x30, 0x01, 0x67, 0x2B, 0xFE, 0xD7, 0xAB, 0x76,
0xCA, 0x82, 0xC9, 0x7D, 0xFA, 0x59, 0x47, 0xF0, 0xAD, 0xD4, 0xA2, 0xAF, 0x9C, 0xA4, 0x72, 0xC0,
0xB7, 0xFD, 0x93, 0x26, 0x36, 0x3F, 0xF7, 0xCC, 0x34, 0xA5, 0xE5, 0xF1, 0x71, 0xD8, 0x31, 0x15,
0x04, 0xC7, 0x23, 0xC3, 0x18, 0x96, 0x05, 0x9A, 0x07, 0x12, 0x80, 0xE2, 0xEB, 0x27, 0xB2, 0x75,
0x09, 0x83, 0x2C, 0x1A, 0x1B, 0x6E, 0x5A, 0xA0, 0x52, 0x3B, 0xD6, 0xB3, 0x29, 0xE3, 0x2F, 0x84,
0x53, 0xD1, 0x00, 0xED, 0x20, 0xFC, 0xB1, 0x5B, 0x6A, 0xCB, 0xBE, 0x39, 0x4A, 0x4C, 0x58, 0xCF,
0xD0, 0xEF, 0xAA, 0xFB, 0x43, 0x4D, 0x33, 0x85, 0x45, 0xF9, 0x02, 0x7F, 0x50, 0x3C, 0x9F, 0xA8,
0x51, 0xA3, 0x40, 0x8F, 0x92, 0x9D, 0x38, 0xF5, 0xBC, 0xB6, 0xDA, 0x21, 0x10, 0xFF, 0xF3, 0xD2,
0xCD, 0x0C, 0x13, 0xEC, 0x5F, 0x97, 0x44, 0x17, 0xC4, 0xA7, 0x7E, 0x3D, 0x64, 0x5D, 0x19, 0x73,
0x60, 0x81, 0x4F, 0xDC, 0x22, 0x2A, 0x90, 0x88, 0x46, 0xEE, 0xB8, 0x14, 0xDE, 0x5E, 0x0B, 0xDB,
0xE0, 0x32, 0x3A, 0x0A, 0x49, 0x06, 0x24, 0x5C, 0xC2, 0xD3, 0xAC, 0x62, 0x91, 0x95, 0xE4, 0x79,
0xE7, 0xC8, 0x37, 0x6D, 0x8D, 0xD5, 0x4E, 0xA9, 0x6C, 0x56, 0xF4, 0xEA, 0x65, 0x7A, 0xAE, 0x08,
0xBA, 0x78, 0x25, 0x2E, 0x1C, 0xA6, 0xB4, 0xC6, 0xE8, 0xDD, 0x74, 0x1F, 0x4B, 0xBD, 0x8B, 0x8A,
0x70, 0x3E, 0xB5, 0x66, 0x48, 0x03, 0xF6, 0x0E, 0x61, 0x35, 0x57, 0xB9, 0x86, 0xC1, 0x1D, 0x9E,
0xE1, 0xF8, 0x98, 0x11, 0x69, 0xD9, 0x8E, 0x94, 0x9B, 0x1E, 0x87, 0xE9, 0xCE, 0x55, 0x28, 0xDF,
0x8C, 0xA1, 0x89, 0x0D, 0xBF, 0xE6, 0x42, 0x68, 0x41, 0x99, 0x2D, 0x0F, 0xB0, 0x54, 0xBB, 0x16];
//逆S盒
$ss = [
0x52, 0x09, 0x6A, 0xD5, 0x30, 0x36, 0xA5, 0x38, 0xBF, 0x40, 0xA3, 0x9E, 0x81, 0xF3, 0xD7, 0xFB,
0x7C, 0xE3, 0x39, 0x82, 0x9B, 0x2F, 0xFF, 0x87, 0x34, 0x8E, 0x43, 0x44, 0xC4, 0xDE, 0xE9, 0xCB,
0x54, 0x7B, 0x94, 0x32, 0xA6, 0xC2, 0x23, 0x3D, 0xEE, 0x4C, 0x95, 0x0B, 0x42, 0xFA, 0xC3, 0x4E,
0x08, 0x2E, 0xA1, 0x66, 0x28, 0xD9, 0x24, 0xB2, 0x76, 0x5B, 0xA2, 0x49, 0x6D, 0x8B, 0xD1, 0x25,
0x72, 0xF8, 0xF6, 0x64, 0x86, 0x68, 0x98, 0x16, 0xD4, 0xA4, 0x5C, 0xCC, 0x5D, 0x65, 0xB6, 0x92,
0x6C, 0x70, 0x48, 0x50, 0xFD, 0xED, 0xB9, 0xDA, 0x5E, 0x15, 0x46, 0x57, 0xA7, 0x8D, 0x9D, 0x84,
0x90, 0xD8, 0xAB, 0x00, 0x8C, 0xBC, 0xD3, 0x0A, 0xF7, 0xE4, 0x58, 0x05, 0xB8, 0xB3, 0x45, 0x06,
0xD0, 0x2C, 0x1E, 0x8F, 0xCA, 0x3F, 0x0F, 0x02, 0xC1, 0xAF, 0xBD, 0x03, 0x01, 0x13, 0x8A, 0x6B,
0x3A, 0x91, 0x11, 0x41, 0x4F, 0x67, 0xDC, 0xEA, 0x97, 0xF2, 0xCF, 0xCE, 0xF0, 0xB4, 0xE6, 0x73,
0x96, 0xAC, 0x74, 0x22, 0xE7, 0xAD, 0x35, 0x85, 0xE2, 0xF9, 0x37, 0xE8, 0x1C, 0x75, 0xDF, 0x6E,
0x47, 0xF1, 0x1A, 0x71, 0x1D, 0x29, 0xC5, 0x89, 0x6F, 0xB7, 0x62, 0x0E, 0xAA, 0x18, 0xBE, 0x1B,
0xFC, 0x56, 0x3E, 0x4B, 0xC6, 0xD2, 0x79, 0x20, 0x9A, 0xDB, 0xC0, 0xFE, 0x78, 0xCD, 0x5A, 0xF4,
0x1F, 0xDD, 0xA8, 0x33, 0x88, 0x07, 0xC7, 0x31, 0xB1, 0x12, 0x10, 0x59, 0x27, 0x80, 0xEC, 0x5F,
0x60, 0x51, 0x7F, 0xA9, 0x19, 0xB5, 0x4A, 0x0D, 0x2D, 0xE5, 0x7A, 0x9F, 0x93, 0xC9, 0x9C, 0xEF,
0xA0, 0xE0, 0x3B, 0x4D, 0xAE, 0x2A, 0xF5, 0xB0, 0xC8, 0xEB, 0xBB, 0x3C, 0x83, 0x53, 0x99, 0x61,
0x17, 0x2B, 0x04, 0x7E, 0xBA, 0x77, 0xD6, 0x26, 0xE1, 0x69, 0x14, 0x63, 0x55, 0x21, 0x0C, 0x7D];
/**
* 密鑰擴展
* @param $keys
*/
function aes_key_extend($keys)
{
$w = [];
global $rcon;
for ($i = 0; $i < strlen($keys); $i += 4) {
$first = ord($keys{$i}) << 24;
$second = ord($keys{$i + 1}) << 16;
$third = ord($keys{$i + 2}) << 8;
$fourth = ord($keys{$i + 3});
$w[] = ($first | $second | $third | $fourth);
}
for ($n = 4; $n <= 43; $n++) {
if ($n % 4 !== 0) {
$w[$n] = $w[$n - 4] ^ $w[$n - 1];
} else {
$mix = (($w[$n - 1] & 0xFF000000) >> 24) | (($w[$n - 1] & 0x00FFFFFF) << 8);
$mix = subBytes($mix);
$w[$n] = (($w[$n - 4] ^ $mix ^ $rcon[($n / 4) - 1]));
}
}
return $w;
}
/**
* 位元組替換，將32位key按照S盒替換，高4位為行數，低4位為列數
* @param $keys
* @return int
*/
function subBytes($keys)
{
$first = getSValue(((((0xFF000000 & $keys) >> 24) & 0xF0) >> 4) * 16 + (((0xFF000000 & $keys) >> 24) & 0xF)) << 24;
$second = getSValue(((((0x00FF0000 & $keys) >> 16) & 0xF0) >> 4) * 16 + (((0x00FF0000 & $keys) >> 16) & 0xF)) << 16;
$third = getSValue(((((0x0000FF00 & $keys) >> 8) & 0xF0) >> 4) * 16 + (((0x0000FF00 & $keys) >> 8) & 0xF)) << 8;
$fourth = getSValue((((0x000000FF & $keys) & 0xF0) >> 4) * 16 + ((0x000000FF & $keys) & 0xF));
return $first | $second | $third | $fourth;
}
/**
* 將8位位元組按S盒規則替換
* @param $key
* @param $type
*/
function subByte($key, $type = 1)
{
$row = ($key & 0xF0) >> 4;
$col = ($key & 0xF);
return getSValue($row * 16 + $col, $type);
}
/**
* 將16個位元組轉成4*4的矩陣，并用S盒替換
* @param $plainText
* @return array
*/
function to4x4Array($plainText)
{
$states = [];
for ($i = 0; $i < 4; $i++) {
for ($j = 0; $j < 4; $j++) {
$states[] = ord($plainText{($j === 0 ? $i : 4 * $j + $i)});
}
}
return $states;
}
function getSValue($key, $type = 1)
{
global $s, $ss;
return $type === 1 ? $s[$key] : $ss[$key];
}
/**
* 行移位
* 第0行不變，第i行左移i位 i>0
* @param &$arr
* @param $type
*/
function shiftRows(&$arr, $type = 1)
{
for ($i = 1; $i < 4; $i++) {
$index = 4 * $i;
$temp = $arr;
for ($j = 0; $j < 4; $j++) {
$key = ($index + $i + $j) > (4 * $i + 3) ? 4 * $i - 1 + ($index + $i + $j - 4 * $i - 3) : $index + $j + $i;
if ($type === 2) {
$key = ($index + $j - $i < 4 * $i) ? 4 * ($i + 1) - (4 * $i - ($index + $j - $i)) : $index + $j - $i;
}
$arr[$index + $j] = $temp[$key];
}
}
}
/**
* 列混合
* @param $arr
* @param $type
*/
function mixColumns(&$arr, $type = 1)
{
global $constArray, $constArrayReverse;
$mixStates = [];
for ($i = 0; $i < 16; $i++) {
$result = 0;
for ($j = 0; $j < 4; $j++) {
$result ^= aes_multi($arr[4 * $j + $i % 4], $type === 1 ? $constArray[4 * (floor($i / 4)) + $j] : $constArrayReverse[4 * (floor($i / 4)) + $j]);
}
$mixStates[$i] = $result;
}
$arr = $mixStates;
}
function roundAddKey($states, $keys, $round = 0)
{
static $result = [];
$tempStates = $states;
if ($round > 10) {
return implode('', array_map(function ($n) {
return sprintf("%02X", $n);
}, $tempStates));
}
if ($round !== 0) {
$tempStates = [];
foreach ($states as $k => $val) {
$tempStates[] = subByte($val);
}
shiftRows($tempStates);
if ($round !== 10) { //最后一輪無需列混合
mixColumns($tempStates);
}
}
foreach ($tempStates as $k2 => $val2) {
$result[$round][] = $val2 ^ $keys[$round][$k2];
}
return roundAddKey($result[$round], $keys, ++$round);
}
function roundReverseAddKey($states, $keys, $round = 10)
{
static $result = [];
$tempStates = [];
foreach ($states as $k => $val) {
$tempStates[] = $val ^ $keys[$round][$k];
}
if ($round === 0) {
$result[$round] = $tempStates;
$newest = [];
for ($i = 0; $i < 4; $i++) {
for ($j = 0; $j < 4; $j++) {
$newest[] = $tempStates[4 * $j + $i];
}
}
return implode('', array_map(function ($n) {
return chr($n);
}, $newest));
} else if ($round !== 10) {
mixColumns($tempStates, 2);
}
shiftRows($tempStates, 2);
foreach ($tempStates as $k => $state) {
$result[$round][] = subByte($state, 2);
}
return roundReverseAddKey($result[$round], $keys, --$round);
}
function addRoundKey($states, $extendKeys, $type = 1)
{
$new4x4Keys = [];
$cloneStates = $states;
$roundKeys = array_chunk($extendKeys, 4);
foreach ($roundKeys as $k => $keys) {
foreach ($keys as $index => $key) {
$temp = [];
$temp[] = ($key & 0xFF000000) >> 24;
$temp[] = ($key & 0x00FF0000) >> 16;
$temp[] = ($key & 0x0000FF00) >> 8;
$temp[] = ($key & 0xFF);
for ($row = 0; $row < 4; $row++) {
$new4x4Keys[$k][$row * 4 + $index] = $temp[$row];
}
ksort($new4x4Keys[$k]);
}
}
return $type === 1 ?
roundAddKey($cloneStates, $new4x4Keys, 0) :
roundReverseAddKey($cloneStates, $new4x4Keys, 10);
}
function php_aes_encrypt($key, $plain)
{
return addRoundKey(to4x4Array($plain), aes_key_extend($key));
}
function php_aes_decrypt($key, $plain)
{
$states = [];
for ($i = 0; $i < 32; $i += 2) {
$states[] = hexdec($plain{$i} . $plain{$i + 1});
}
return addRoundKey($states, aes_key_extend($key), 2);
}
$p = 'abcdefghijklmnop';
$k = '1234567890abcdef';
$plain = php_aes_encrypt($k, $p);
var_dump($plain);
var_dump(php_aes_decrypt($k, $plain));
本文來自博客園，作者：淙淙溪流，轉載請注明原文鏈接：https://www.cnblogs.com/pitmanhuang/p/16177511.html
轉載請註明出處，本文鏈接：https://www.uj5u.com/houduan/464016.html
標籤：PHP
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