如何使用openssl_decrypt解密加密字符串

Question

我的代码如下：

<?php

class Encryption{
    
    protected $data, $encryption_type, $key, $iv;

    public function __construct(){
        $mydata = "Is this safe";
        $encryption = $this->secured_encryption($mydata);

        // Decrypting data
        $data_to_decrypt = $encryption;
        $this->decrypt_data($data_to_decrypt);
    }

    public function secured_encryption($data){
        $this->data = $data;
        $this->encryption_type = "AES-256-CBC"; // cipher algorithm
        $this->key = ['6d2d823df2e08c0d3cdf70f148998d49', 'fdb3a18c7b0a322fdb3a18c7b0a320d3'];
        $this->iv = openssl_random_pseudo_bytes(openssl_cipher_iv_length($this->encryption_type));
        $encrypted_data = openssl_encrypt($this->data, $this->encryption_type, $this->key[0], OPENSSL_RAW_DATA, $this->iv);
        $final_encryption = hash_hmac('SHA3-512', $encrypted_data, $this->key[1], true);
        $output = base64_encode($this->iv.$final_encryption.$encrypted_data);

        if($output):
            print("Encrypted data: {$output}<br/>");
        else:
            print("Error in encrypting data");
        endif;
    }

    public function decrypt_data($data){
        $this->data = base64_decode($data);
        $this->encryption_type = "AES-256-CBC"; // cipher algorithm
        $this->key = ['6d2d823df2e08c0d3cdf70f148998d49', 'fdb3a18c7b0a322fdb3a18c7b0a320d3'];
        $ivlen = openssl_cipher_iv_length($this->encryption_type);
        $this->iv = substr($this->data, 0, $ivlen);
        $hmac = substr($this->data, $ivlen, $sha2len = 32);
        $decrypt_data = substr($this->data, $ivlen, $sha2len);
        $final_decryption = openssl_decrypt($decrypt_data, $this->encryption_type, $this->key[0], OPENSSL_RAW_DATA, $this->iv);
        $calcmac = hash_hmac('SHA3-512', $decrypt_data, $this->key[1], true);

        if(hash_equals($hmac, $calcmac)):
            print($final_decryption);
        else:
            print("Error in decrypting data");
        endif;
    }
}

$encryption = Encryption();

?> 

有人来帮我吗

Answer 1

代码中有几个小问题：

>

secured_encryption方法中缺少返回语句。这是错误消息的触发器(hash_equals():Expected known_string为字符串，给定bool)，因为$HMAC不包含字符串，而是false。因此，在secured_encryption结尾处，您必须添加：

php prettyprint-override">return $output;

有了这个，加密工作了，但解密还不起作用。

$hmac = substr($this->data, $ivlen, $sha2len = 32);

必须替换为：

$hmac = substr($this->data, $ivlen, $sha2len = 64);   

分离数据时，从$ivlen+$sha2len位置开始，将所有内容考虑到底，即：

$decrypt_data = substr($this->data, $ivlen, $sha2len); 

必须替换为：

$decrypt_data = substr($this->data, $ivlen + $sha2len);

Encrypted data: uTjcPmLK8jTktJ0oy5AqB40d5YFuAbgXMHfNEM6+JOH+DtyYAhckcv3mkLhdOvUqPlriKqYjHO6cpJI3ZdoTSS4lqDr0eH0MMiUpJMSXcan81irvobcdIV+rvaMPPRj7
Is this safe