我正在使用serpro的Android-PHP-Encrypt-Decrypt项目来使用PHP加密图像并使用JAVA解密它们。如果仅在PHP中完成加密和解密，但是当我尝试使用java加密时，我收到错误的说法＆＃39; java.lang.Exception: [encrypt] Input length not multiple of 16 bytes＆＃39;当我尝试解密由php加密的图像时，我得到：＆＃39; java.lang.Exception: [decrypt] For input string: "nu"＆＃39;
这是我的代码：
serpro的Mcrypt php课程：
<?php
class MCrypt
{
private $iv = 'fedcba9876543210';
private $key = '0123456789abcdef';
function __construct()
{
}
function encrypt($str, $isBinary = false) {
$iv = $this->iv;
$str = $isBinary ? $str : utf8_decode($str);
$td = mcrypt_module_open('rijndael-128', ' ', 'cbc', $iv);
mcrypt_generic_init($td, $this->key, $iv);
$encrypted = mcrypt_generic($td, $str);
mcrypt_generic_deinit($td);
mcrypt_module_close($td);
return $isBinary ? $encrypted : bin2hex($encrypted);
}
function decrypt($code, $isBinary = false) {
$code = $isBinary ? $code : $this->hex2bin($code);
$iv = $this->iv;
$td = mcrypt_module_open('rijndael-128', ' ', 'cbc', $iv);
mcrypt_generic_init($td, $this->key, $iv);
$decrypted = mdecrypt_generic($td, $code);
mcrypt_generic_deinit($td);
mcrypt_module_close($td);
return $isBinary ? trim($decrypted) : utf8_encode(trim($decrypted));
}
protected function hex2bin($hexdata) {
$bindata = '';
for ($i = 0; $i < strlen($hexdata); $i += 2) {
$bindata .= chr(hexdec(substr($hexdata, $i, 2)));
}
return $bindata;
}
}
我的Php类来加密图像：
<?php
require_once('MCrypt.php');
$file = file_get_contents($argv[1]);
$mcrypt = new MCrypt();
$encrypted = $mcrypt->encrypt($file, true); //true to set is as binary
file_put_contents($argv[1], $encrypted);
serpro JAVA课程：
import java.security.NoSuchAlgorithmException;
import javax.crypto.Cipher;
import javax.crypto.NoSuchPaddingException;
import javax.crypto.spec.IvParameterSpec;
import javax.crypto.spec.SecretKeySpec;
public class MCrypt {
static char[] HEX_CHARS = {'0','1','2','3','4','5','6','7','8','9','a','b','c','d','e','f'};
private String iv = "fedcba9876543210";//Dummy iv (CHANGE IT!)
private IvParameterSpec ivspec;
private SecretKeySpec keyspec;
private Cipher cipher;
private String SecretKey = "0123456789abcdef";//Dummy secretKey (CHANGE IT!)
public MCrypt()
{
ivspec = new IvParameterSpec(iv.getBytes());
keyspec = new SecretKeySpec(SecretKey.getBytes(), "AES");
try {
cipher = Cipher.getInstance("AES/CBC/NoPadding");
} catch (NoSuchAlgorithmException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (NoSuchPaddingException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
public byte[] encrypt(String text) throws Exception
{
if(text == null || text.length() == 0)
throw new Exception("Empty string");
byte[] encrypted = null;
try {
cipher.init(Cipher.ENCRYPT_MODE, keyspec, ivspec);
encrypted = cipher.doFinal(padString(text).getBytes());
} catch (Exception e)
{
throw new Exception("[encrypt] " + e.getMessage());
}
return encrypted;
}
public byte[] decrypt(String code) throws Exception
{
if(code == null || code.length() == 0)
throw new Exception("Empty string");
System.out.println("after if");
byte[] decrypted = null;
try {
System.out.println("in try");
cipher.init(Cipher.DECRYPT_MODE, keyspec, ivspec);
System.out.println("2");
decrypted = cipher.doFinal(hexToBytes(code));
System.out.println("3");
//Remove trailing zeroes
if( decrypted.length > 0)
{
System.out.println("in if");
int trim = 0;
for( int i = decrypted.length - 1; i >= 0; i-- ) if( decrypted[i] == 0 ) trim++;
if( trim > 0 )
{
byte[] newArray = new byte[decrypted.length - trim];
System.arraycopy(decrypted, 0, newArray, 0, decrypted.length - trim);
decrypted = newArray;
}
}
System.out.println("after if");
} catch (Exception e)
{
throw new Exception("[decrypt] " + e.getMessage());
}
return decrypted;
}
public static String bytesToHex(byte[] buf)
{
char[] chars = new char[2 * buf.length];
for (int i = 0; i < buf.length; ++i)
{
chars[2 * i] = HEX_CHARS[(buf[i] & 0xF0) >>> 4];
chars[2 * i + 1] = HEX_CHARS[buf[i] & 0x0F];
}
return new String(chars);
}
public static byte[] hexToBytes(String str) {
if (str==null) {
return null;
} else if (str.length() < 2) {
return null;
} else {
System.out.println("else");
int len = str.length() / 2;
System.out.println(len);
byte[] buffer = new byte[len];
for (int i=0; i<len; i++) {
System.out.println(str.substring(i*2,i*2+2));
buffer[i] = (byte) Integer.parseInt(str.substring(i*2,i*2+2),16);
System.out.println("in for");
}
return buffer;
}
}
private static String padString(String source)
{
char paddingChar = 0;
int size = 16;
int x = source.length() % size;
int padLength = size - x;
for (int i = 0; i < padLength; i++)
{
source += paddingChar;
}
return source;
}
}
我的Java课程：
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
public class Decrypt {
public static void main(String[] args) {
File file = new File(args[0]);
FileInputStream fin = null;
try {
fin = new FileInputStream(file);
byte fileContent[] = new byte[(int) file.length()];
fin.read(fileContent);
String fileToDecrypt = new String(fileContent);
MCrypt crypter = new MCrypt();
String decrypted = new String(crypter.decrypt(fileToDecrypt));
System.out.println(decrypted);
} catch (FileNotFoundException e) {
System.out.println("File not found" + e);
} catch (IOException ioe) {
System.out.println("Exception while reading file " + ioe);
} catch (Exception e){
System.out.println("An exception occured: " + e);
} finally {
try {
if (fin != null) {
fin.close();
}
} catch (IOException ioe) {
System.out.println("Error while closing stream: " + ioe);
}
}
}
}
答案 0 :(得分：0)
String fileToDecrypt = null;
while ((currentLine = input.readLine()) != null) {
fileToDecrypt = fileToDecrypt + currentLine;
}
这将为您提供一个以＆＃34; n＆＃34;，＆＃34; u＆＃34;，＆＃34; l＆＃34;，＆＃34; l＆＃34;开头的字符串。
尝试将fileToDecrypt初始化为空字符串。
甚至更好，使用StringBuilder。
decrypted = new String(crypter.decrypt(fileToDecrypt));
这不应该是JPEG图像吗？您无法将其转换为String。
改为使用byte[]。
（同样的问题可能适用于您尝试逐行读入字符串的加密输入数据。如果这是二进制数据，则也不能在那里使用String。）
答案 1 :(得分：0)
要使用php加密，请使用非常简单的方法。使用称为md5（）的内置函数php 要查看其工作原理，请观看此视频 https://youtu.be/SMLv9SWxbfA