加解密代码摘自网络，出处忘记了，这里就不附链接，对原创说声抱歉！
先附上代码：

<?phpClass SM4Util
{public $SM4_CK = [0x00070e15, 0x1c232a31, 0x383f464d, 0x545b6269,0x70777e85, 0x8c939aa1, 0xa8afb6bd, 0xc4cbd2d9,0xe0e7eef5, 0xfc030a11, 0x181f262d, 0x343b4249,0x50575e65, 0x6c737a81, 0x888f969d, 0xa4abb2b9,0xc0c7ced5, 0xdce3eaf1, 0xf8ff060d, 0x141b2229,0x30373e45, 0x4c535a61, 0x686f767d, 0x848b9299,0xa0a7aeb5, 0xbcc3cad1, 0xd8dfe6ed, 0xf4fb0209,0x10171e25, 0x2c333a41, 0x484f565d, 0x646b7279];public $SM4_Sbox = [0xd6, 0x90, 0xe9, 0xfe, 0xcc, 0xe1, 0x3d, 0xb7, 0x16, 0xb6, 0x14, 0xc2, 0x28, 0xfb, 0x2c, 0x05,0x2b, 0x67, 0x9a, 0x76, 0x2a, 0xbe, 0x04, 0xc3, 0xaa, 0x44, 0x13, 0x26, 0x49, 0x86, 0x06, 0x99,0x9c, 0x42, 0x50, 0xf4, 0x91, 0xef, 0x98, 0x7a, 0x33, 0x54, 0x0b, 0x43, 0xed, 0xcf, 0xac, 0x62,0xe4, 0xb3, 0x1c, 0xa9, 0xc9, 0x08, 0xe8, 0x95, 0x80, 0xdf, 0x94, 0xfa, 0x75, 0x8f, 0x3f, 0xa6,0x47, 0x07, 0xa7, 0xfc, 0xf3, 0x73, 0x17, 0xba, 0x83, 0x59, 0x3c, 0x19, 0xe6, 0x85, 0x4f, 0xa8,0x68, 0x6b, 0x81, 0xb2, 0x71, 0x64, 0xda, 0x8b, 0xf8, 0xeb, 0x0f, 0x4b, 0x70, 0x56, 0x9d, 0x35,0x1e, 0x24, 0x0e, 0x5e, 0x63, 0x58, 0xd1, 0xa2, 0x25, 0x22, 0x7c, 0x3b, 0x01, 0x21, 0x78, 0x87,0xd4, 0x00, 0x46, 0x57, 0x9f, 0xd3, 0x27, 0x52, 0x4c, 0x36, 0x02, 0xe7, 0xa0, 0xc4, 0xc8, 0x9e,0xea, 0xbf, 0x8a, 0xd2, 0x40, 0xc7, 0x38, 0xb5, 0xa3, 0xf7, 0xf2, 0xce, 0xf9, 0x61, 0x15, 0xa1,0xe0, 0xae, 0x5d, 0xa4, 0x9b, 0x34, 0x1a, 0x55, 0xad, 0x93, 0x32, 0x30, 0xf5, 0x8c, 0xb1, 0xe3,0x1d, 0xf6, 0xe2, 0x2e, 0x82, 0x66, 0xca, 0x60, 0xc0, 0x29, 0x23, 0xab, 0x0d, 0x53, 0x4e, 0x6f,0xd5, 0xdb, 0x37, 0x45, 0xde, 0xfd, 0x8e, 0x2f, 0x03, 0xff, 0x6a, 0x72, 0x6d, 0x6c, 0x5b, 0x51,0x8d, 0x1b, 0xaf, 0x92, 0xbb, 0xdd, 0xbc, 0x7f, 0x11, 0xd9, 0x5c, 0x41, 0x1f, 0x10, 0x5a, 0xd8,0x0a, 0xc1, 0x31, 0x88, 0xa5, 0xcd, 0x7b, 0xbd, 0x2d, 0x74, 0xd0, 0x12, 0xb8, 0xe5, 0xb4, 0xb0,0x89, 0x69, 0x97, 0x4a, 0x0c, 0x96, 0x77, 0x7e, 0x65, 0xb9, 0xf1, 0x09, 0xc5, 0x6e, 0xc6, 0x84,0x18, 0xf0, 0x7d, 0xec, 0x3a, 0xdc, 0x4d, 0x20, 0x79, 0xee, 0x5f, 0x3e, 0xd7, 0xcb, 0x39, 0x48];/*** 系统参数*/public $SM4_FK = [0xA3B1BAC6, 0x56AA3350, 0x677D9197, 0xB27022DC];private $key = [];//16个 HEXHEX格式的数组 16字节 128bits  为了操作方便,直接存成十进制private $skey = [];//记录每轮加密的秘钥 记录成十进制private $block_size = 32;/*** 字符串转16进制* @param $str* @return string*/public function strToHex($string){$hex="";for($i=0;$i<strlen($string);$i++)$hex.=dechex(ord($string[$i]));$hex=strtoupper($hex);if(strlen($hex)>32){return substr($hex,0,32);}else{return $hex;}}/**设置加密秘钥** @param $key 32个十六进制的字符** @return $this* @throws Exception*/public function setKey($key){$key = $this->strToHex($key);$this->key = $this->preProcess($key);$this->setSkey();return $this;}/*** 计算每轮加密需要的秘钥*/private function setSkey(){$skey = [];for ($i = 0; $i < 4; $i++) {$skey[] = self::SM4_FK[$i] ^ ($this->key[4 * $i] << 24 | $this->key[4 * $i + 1] << 16 | $this->key[4 * $i + 2] << 8 | $this->key[4 * $i + 3]);}for ($k = 0; $k < 32; $k++) {$tmp = $skey[$k + 1] ^ $skey[$k + 2] ^ $skey[$k + 3] ^ self::SM4_CK[$k];//非线性化操作$buf = (self::SM4_Sbox[($tmp >> 24) & 0xff]) << 24 |(self::SM4_Sbox[($tmp >> 16) & 0xff]) << 16 |(self::SM4_Sbox[($tmp >> 8) & 0xff]) << 8 |(self::SM4_Sbox[$tmp & 0xff]);//线性化操作$skey[] = $skey[$k] ^ ($buf ^ $this->sm4Rotl32($buf, 13) ^ $this->sm4Rotl32($buf, 23));$this->skey[] = $skey[$k + 4];}}/**32比特的buffer中循环左移n位** @param $buf int 可以传递进10进制 也可以是0b开头的二进制* @param $n int 向左偏移n位** @return int* reference http://blog.csdn.net/w845695652/article/details/6522285*/private function sm4Rotl32($buf, $n){return (($buf << $n) & 0xffffffff) | ($buf >> (32 - $n));}/*** 对字符串加密** @param $plainText** @return string* @throws Exception*/public function encryptData($plainText){$bytes = bin2hex($plainText);$need_pad_length = $this->block_size - strlen($bytes) % $this->block_size;$pad_bytes = str_pad($bytes,strlen($bytes) + $need_pad_length,sprintf("%02x", $need_pad_length / 2),STR_PAD_RIGHT);$chunks = str_split($pad_bytes, $this->block_size);return strtolower(implode('', array_map(function ($chunk) {return $this->encrypt($chunk);}, $chunks)));}/**SM4加密单个片段(128bit)** @param $text string 32个十六进制字符串** @return string* @throws Exception*/public function encrypt($text){$x = $re = [];$t = $this->preProcess($text);for ($i = 0; $i < 4; $i++) {$x[] = $t[$i * 4] << 24 |$t[$i * 4 + 1] << 16 |$t[$i * 4 + 2] << 8 |$t[$i * 4 + 3];}for ($k = 0; $k < 32; $k++) {$tmp = $x[$k + 1] ^ $x[$k + 2] ^ $x[$k + 3] ^ $this->skey[$k];$buf = self::SM4_Sbox[($tmp >> 24) & 0xff] << 24 |self::SM4_Sbox[($tmp >> 16) & 0xff] << 16 |self::SM4_Sbox[($tmp >> 8) & 0xff] << 8 |self::SM4_Sbox[$tmp & 0xff];$x[$k + 4] = $x[$k] ^ $buf^ $this->sm4Rotl32($buf, 2)^ $this->sm4Rotl32($buf, 10)^ $this->sm4Rotl32($buf, 18)^ $this->sm4Rotl32($buf, 24);}for ($i = 0; $i < 4; $i++) {$re[] = ($x[35 - $i] >> 24) & 0xff;$re[] = ($x[35 - $i] >> 16) & 0xff;$re[] = ($x[35 - $i] >> 8) & 0xff;$re[] = $x[35 - $i] & 0xff;}return $this->wrapResult($re);}/**预处理16字节长度的16进制字符串 返回10进制的数组 数组大小为16** @param $text** @return array* @throws Exception*/private function preProcess($text){preg_match('/[0-9a-f]{32}/', strtolower($text), $re);if (empty($re)) {throw new Exception('error input format!');}$key = $re[0];for ($i = 0; $i < 16; $i++) {$result[] = hexdec($key[2 * $i] . $key[2 * $i + 1]);}return $result;}/**将十进制结果包装成16进制字符串输出** @param $result** @return string*/private function wrapResult($result){$hex_str = '';foreach ($result as $v) {$tmp = dechex($v);$len = strlen($tmp);if ($len == 1)//不足两位十六进制的数 在前面补一个0,保证输出也是32个16进制字符{$hex_str .= '0';}$hex_str .= $tmp;}return strtoupper($hex_str);}/**SM4解密单个片段(128bits)** @param $text string 32个16进制字符串** @return string* @throws Exception*/public function decrypt($text){$x = $re = [];$t = $this->preProcess($text);for ($i = 0; $i < 4; $i++) {$x[] = $t[4 * $i] << 24 |$t[4 * $i + 1] << 16 |$t[4 * $i + 2] << 8 |$t[4 * $i + 3];}for ($k = 0; $k < 32; $k++) {$tmp = $x[$k + 1] ^ $x[$k + 2] ^ $x[$k + 3] ^ $this->skey[31 - $k];$buf = (self::SM4_Sbox[($tmp >> 24) & 0xff]) << 24 |(self::SM4_Sbox[($tmp >> 16) & 0xff]) << 16 |(self::SM4_Sbox[($tmp >> 8) & 0xff]) << 8 |(self::SM4_Sbox[$tmp & 0xff]);$x[$k + 4] = $x[$k] ^ $buf^ $this->sm4Rotl32($buf, 2)^ $this->sm4Rotl32($buf, 10)^ $this->sm4Rotl32($buf, 18)^ $this->sm4Rotl32($buf, 24);}for ($i = 0; $i < 4; $i++) {$re[] = ($x[35 - $i] >> 24) & 0xff;$re[] = ($x[35 - $i] >> 16) & 0xff;$re[] = ($x[35 - $i] >> 8) & 0xff;$re[] = $x[35 - $i] & 0xff;}return $this->wrapResult($re);}public function decryptData($cipherText){$chunks = str_split($cipherText, $this->block_size);$decrypt_text_data = implode('', array_map(function ($chunk) {return $this->decrypt($chunk);}, $chunks));$pad_length = hexdec(substr($decrypt_text_data, -2));return strtolower(hex2bin(preg_replace(sprintf("/%s$/", str_repeat(sprintf("%02x", $pad_length), $pad_length)),'',$decrypt_text_data)));}}$data=["DOC_ID"=>"",'STATE'=>"1"
];
$sm4 = new SM4Util();
$original_plain_text_data = json_encode($data,true);$key = 'henan202012272GOVCms';$origin_encrypted_text = '798c4eceb3a46ca50fe55331e472ffee1b9a88e2847156252c009b3a1c8a1d1c';
$encrypted_text_data = $sm4->setKey($key)->encryptData($original_plain_text_data);
echo '<br>';
echo"自己加密：".$encrypted_text_data;
echo '<br>长度：'.strlen($encrypted_text_data);
echo '<br>';
echo"自己解密：". $sm4->setKey($key)->decryptData($encrypted_text_data);echo '<br>';echo"原文------：".$origin_encrypted_text;
echo '<br>长度：'.strlen($origin_encrypted_text);
//$encrypted_text_2_plain_text = $sm4->setKey($key)->decryptData($encrypted_text_data);
$original_decrypted_text = $sm4->setKey($key)->decryptData($origin_encrypted_text);
echo '<br>';
echo "原文解密：".$original_decrypted_text ;
echo '<br>';//echo "明文：" . $data . "\n";
//$a = $sm4->encrypt($key, $data);
//echo "加密结果：" . $a . "\n";
//$b = $sm4->decrypt($key, $data);
//var_dump($b);exit;
//echo "解密结果：" . $b . "\n";//list($t1, $t2) = explode(' ', microtime());
//$st = (float)sprintf('%.0f', (floatval($t1) + floatval($t2)) * 1000);
//for ($i = 0; $i< 1000; $i++) {
//    $sm4 = new SM4();
//    $a = $sm4->encrypt($key, $data);
//}
//list($t1, $t2) = explode(' ', microtime());
//$et = (float)sprintf('%.0f', (floatval($t1) + floatval($t2)) * 1000);
//$endtime = $et-$st;
//
//echo "time:" . $endtime . "\n";

我这里要说明的是，php分32位和64位2个版本，我在使用上述方法时，对接的接口，64位可用。so，32位和64位加密结果不一致，需要注意版本！