Question

以下是我要做的事情：

1）从用户那里获得普通的NSString

2）使用带有16字节长密钥的AES128进行加密（例如：0123456789abcdef）

3）将其发送到PHP服务器

4）将其解密为纯文本

但是如果输入的纯文本太长或太短，解密就会失败。

以下是我的工作：

链接https://tharindufit.wordpress.com/2011/12/15/aes128-encryption-in-ios-and-decryption-in-php/ 提供

NSData + AEScrypt.h

的NSData + AEScrypt.m

的NSString + AEScrypt.h

的NSString + AEScrypt.m

在ViewController.m

中

#import "ViewController.h"
#import "NSString+AESCrypt.h"

...

-(void) sendPost {
//1. prepare 16-bytes long key
NSString *theKey = @"0123456789abcdef";

//2. prepare any plain NSString
NSString *plainString = @"abcdef";

//3. turn NSString into UTF-8 NSData
NSData *plainStringData = [plainString dataUsingEncoding:NSUTF8StringEncoding];

//4. turn UTF-8 NSData into AES128 Encrypted NSData with key
NSData *aesData = [plainStringData AES128EncryptWithKey: theKey];

//5. encode AES data into Base64-encoded NSString
NSString *base64String = [aesData base64EncodedStringWithOptions:0];

//check what the client is sending to the server
NSLog("Client plain text:%@ encrypted text:%@", plainString, base64String);
//Logs:
//Client plain text: abcdef encrypted text: iD+22cYZOlopuScGn42rAg==


/** do normal POST request to server ************/
//6. send 'base64String' to server
//set up parameter
NSString *parameter = [NSString stringWithFormat:@"data=%@", base64String];
NSData *parameterData = [parameter dataUsingEncoding:NSUTF8StringEncoding];

//set up URL
NSURL *url = [NSURL URLWithString: @"http://mywebsite.com/myserver.php"];
NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:url];
[request setHTTPBody:parameterData];

//set up as POST method
[request setHTTPMethod:@"POST"];
[request addValue: @"application/x-www-form-urlencoded; charset=utf-8"  forHTTPHeaderField:@"Content-Type"];
NSURLConnection *connection = [[NSURLConnection alloc]initWithRequest:request delegate:self];
}

myserver.php

<?php //1. receive data from client $data = $_POST['data']; //2. check what the server received echo "Before decrypt:".$data //this echoes: //Before decrypt:iD 22cYZOlopuScGn42rAg== //3. set up the same key as client's key $key = "0123456789abcdef"; //4. decrypt AES $decoded_data = decrypt_password($data, "0123456789abcdef"); //5. see the result echo "After decrypt:".$decoded_data; //this echoes: //After decrypt: abcdef function decrypt_password($pass,$key) { $base64encoded_ciphertext = $pass; $res_non = mcrypt_decrypt(MCRYPT_RIJNDAEL_128, $key, base64_decode($base64encoded_ciphertext), MCRYPT_MODE_ECB); $decrypted = $res_non; $dec_s2 = strlen($decrypted); $padding = ord($decrypted[$dec_s2-1]); $decrypted = substr($decrypted, 0, -$padding); return $decrypted; } ?>

如果一切正常，我应该进入NSLog：

Client plain text: abcdef encrypted text: iD+22cYZOlopuScGn42rAg==

从PHP开始：

Before decrypt:iD 22cYZOlopuScGn42rAg== After decrypt:abcdef

但是如果NSString * plainString太长或太短，我来自PHP：

Before decrypt:pQGKv22BszWe5WN b9oOtQ== After decrypt:

意思是，PHP无法解密它。此外，我意识到＆＃39; +＆＃39;标志消失了＃34;解密之前：＆＃34;回声。但这似乎不是问题，因为有时解密会起作用。

我的问题是为什么解密失败的普通NSString太长或太短？我怎样才能解决这个问题？？我似乎找不到任何解决方案。请帮忙......

Answer 1

找到答案。

当加密字符串包含“+”符号时，PHP会将其转换为空格，因为“+”符号是保留的。

因此，请使用urlencode（）和urldecode（），如下所示：

<?php
$key = 'secretkey';
$string = $_GET['data'];

$string = urlencode($string);
$string = str_replace("+", "%2B",$string);
$string = urldecode($string);
$output = rtrim(mcrypt_decrypt(MCRYPT_RIJNDAEL_256, md5($key), base64_decode($string), MCRYPT_MODE_CBC, md5(md5($key))), "\0");

?>

来自objective-c iOS，AES128加密 - base64编码 - 发布到PHP - PHP中的解码失败有时候

1 个答案: