PHP AES 128 CBC

資料來源: https://gist.github.com/srsbiz/8373451ed3450c0548c3

https://www.php.net/manual/zh/function.mcrypt-encrypt.php

<?php 
function encrypt_mcrypt($msg, $key, $iv = null) {
	$iv_size = mcrypt_get_iv_size(MCRYPT_RIJNDAEL_128, MCRYPT_MODE_CBC);
	if (!$iv) {
		$iv = mcrypt_create_iv($iv_size, MCRYPT_RAND);
	}
	$pad = $iv_size - (strlen($msg) % $iv_size);
	$msg .= str_repeat(chr($pad), $pad);
	$encryptedMessage = mcrypt_encrypt(MCRYPT_RIJNDAEL_128, $key, $msg, MCRYPT_MODE_CBC, $iv);
	return base64_encode($iv . $encryptedMessage);
}
function decrypt_mcrypt($payload, $key) {
	$raw = base64_decode($payload);
	$iv_size = mcrypt_get_iv_size(MCRYPT_RIJNDAEL_128, MCRYPT_MODE_CBC);
	$iv = substr($raw, 0, $iv_size);
	$data = substr($raw, $iv_size);
	$result = mcrypt_decrypt(MCRYPT_RIJNDAEL_128, $key, $data, MCRYPT_MODE_CBC, $iv);
	$ctrlchar = substr($result, -1);
	$ord = ord($ctrlchar);
	if ($ord < $iv_size && substr($result, -ord($ctrlchar)) === str_repeat($ctrlchar, $ord)) {
		$result = substr($result, 0, -ord($ctrlchar));
	}
	return $result;
}

function encrypt_openssl($msg, $key, $iv = null) {
	$iv_size = openssl_cipher_iv_length('AES-128-CBC');
	if (!$iv) {
		$iv = openssl_random_pseudo_bytes($iv_size);
	}
	$encryptedMessage = openssl_encrypt($msg, 'AES-128-CBC', $key, OPENSSL_RAW_DATA, $iv);
	return base64_encode($iv . $encryptedMessage);
}
function decrypt_openssl($payload, $key) {
	$raw = base64_decode($payload);
	$iv_size = openssl_cipher_iv_length('AES-128-CBC');
	$iv = substr($raw, 0, $iv_size);
	$data = substr($raw, $iv_size);
	return openssl_decrypt($data, 'AES-128-CBC', $key, OPENSSL_RAW_DATA, $iv);
}

<?php
    # --- 加密 ---

    # 密钥应该是随机的二进制数据，
    # 开始使用 scrypt, bcrypt 或 PBKDF2 将一个字符串转换成一个密钥
    # 密钥是 16 进制字符串格式
    $key = pack('H*', "bcb04b7e103a0cd8b54763051cef08bc55abe029fdebae5e1d417e2ffb2a00a3");
    
    # 显示 AES-128, 192, 256 对应的密钥长度：
    #16，24，32 字节。
    $key_size =  strlen($key);
    echo "Key size: " . $key_size . "\n";
    
    $plaintext = "This string was AES-256 / CBC / ZeroBytePadding encrypted.";

    # 为 CBC 模式创建随机的初始向量
    $iv_size = mcrypt_get_iv_size(MCRYPT_RIJNDAEL_128, MCRYPT_MODE_CBC);
    $iv = mcrypt_create_iv($iv_size, MCRYPT_RAND);
    

    # 创建和 AES 兼容的密文（Rijndael 分组大小 = 128）
    # 仅适用于编码后的输入不是以 00h 结尾的
    # （因为默认是使用 0 来补齐数据）
    $ciphertext = mcrypt_encrypt(MCRYPT_RIJNDAEL_128, $key,
                                 $plaintext, MCRYPT_MODE_CBC, $iv);

    # 将初始向量附加在密文之后，以供解密时使用
    $ciphertext = $iv . $ciphertext;
    
    # 对密文进行 base64 编码
    $ciphertext_base64 = base64_encode($ciphertext);

    echo  $ciphertext_base64 . "\n";

    # === 警告 ===

    # 密文并未进行完整性和可信度保护，
    # 所以可能遭受 Padding Oracle 攻击。
    
    # --- 解密 ---
    
    $ciphertext_dec = base64_decode($ciphertext_base64);
    
    # 初始向量大小，可以通过 mcrypt_get_iv_size() 来获得
    $iv_dec = substr($ciphertext_dec, 0, $iv_size);
    
    # 获取除初始向量外的密文
    $ciphertext_dec = substr($ciphertext_dec, $iv_size);

    # 可能需要从明文末尾移除 0
    $plaintext_dec = mcrypt_decrypt(MCRYPT_RIJNDAEL_128, $key,
                                    $ciphertext_dec, MCRYPT_MODE_CBC, $iv_dec);
    
    echo  $plaintext_dec . "\n";
?>