简介:AES是一种对称加密方式，旨在取代DES成为广泛使用的标准。虽然语言不同，但是AES的算法是相同的。
关于AES的各种参数请参考下面文章(一定要认真阅读，不然就没办法按照自己的想法进行加密解密)：AES加密 - iOS与Java的同步实现
思路：
先说一下我的想法，iOS端加密由Java解密，Java加密由iOS解密，加密模式采取CBC，密钥长度为256位，初始向量（相当于是加密解密规则）为32位，这个是要对应密钥长度的。
难点：
1、Java对于大于128bits的是不支持的，我们需要将JDK中的local_policy.jar US_export_policy.jar用这里的jar包替换掉，我的mac电脑，JDK路径是资源库/Java/JavaVirtualMachines/jdk1.8.0_111.jdk/Contents/Home/jre/libsecurity
替换的jar包
这样Java才会支持256位的密钥加密。
2、iOS端的kKeySize改为
kCCKeySizeAES256。3、两端的key（加密解密规则）设置成32位字符串。
实现：
iOS端
AESCipher.h
@interface AESCipher : NSObject
NSString * aesEncryptString(NSString *content, NSString *key);
NSString * aesDecryptString(NSString *content, NSString *key);
NSData * aesEncryptData(NSData *data, NSData *key);
NSData * aesDecryptData(NSData *data, NSData *key);
@end
AESCipher.m
#import <CommonCrypto/CommonCryptor.h>
NSString const *kInitVector = @"A-16-Byte-String";
size_t const kKeySize = kCCKeySizeAES256;
NSData * cipherOperation(NSData *contentData, NSData *keyData, CCOperation operation) {
NSUInteger dataLength = contentData.length;
void const *initVectorBytes = [kInitVector dataUsingEncoding:NSUTF8StringEncoding].bytes;
void const *contentBytes = contentData.bytes;
void const *keyBytes = keyData.bytes;
size_t operationSize = dataLength + kCCKeySizeAES256;
void *operationBytes = malloc(operationSize);
size_t actualOutSize = 0;
CCCryptorStatus cryptStatus = CCCrypt(operation,
kCCAlgorithmAES,
kCCOptionPKCS7Padding,
keyBytes,
kKeySize,
initVectorBytes,
contentBytes,
dataLength,
operationBytes,
operationSize,
&actualOutSize);
if (cryptStatus == kCCSuccess) {
return [NSData dataWithBytesNoCopy:operationBytes length:actualOutSize];
}
free(operationBytes);
return nil;
}
NSString * aesEncryptString(NSString *content, NSString *key) {
NSData *contentData = [content dataUsingEncoding:NSUTF8StringEncoding];
NSData *keyData = [key dataUsingEncoding:NSUTF8StringEncoding];
NSData *encrptedData = aesEncryptData(contentData, keyData);
return [encrptedData base64EncodedStringWithOptions:NSDataBase64EncodingEndLineWithLineFeed];
}
NSString * aesDecryptString(NSString *content, NSString *key) {
NSData *contentData = [[NSData alloc] initWithBase64EncodedString:content options:NSDataBase64DecodingIgnoreUnknownCharacters];
NSData *keyData = [key dataUsingEncoding:NSUTF8StringEncoding];
NSData *decryptedData = aesDecryptData(contentData, keyData);
return [[NSString alloc] initWithData:decryptedData encoding:NSUTF8StringEncoding];
}
NSData * aesEncryptData(NSData *contentData, NSData *keyData) {
NSString *hint = [NSString stringWithFormat:@"The key size of AES-%lu should be %lu bytes!", kKeySize * 8, kKeySize];
NSCAssert(keyData.length == kKeySize, hint);
return cipherOperation(contentData, keyData, kCCEncrypt);
}
NSData * aesDecryptData(NSData *contentData, NSData *keyData) {
NSString *hint = [NSString stringWithFormat:@"The key size of AES-%lu should be %lu bytes!", kKeySize * 8, kKeySize];
NSCAssert(keyData.length == kKeySize, hint);
return cipherOperation(contentData, keyData, kCCDecrypt);
}
先自行测试一下：
NSString *plainText = @"战狼2";
//32位key，加解密规则
NSString *key = @"16-Bytes--String16-Bytes--String";
NSString *cipherText = aesEncryptString(plainText, key);
NSLog(@"%@", cipherText);
NSString *decryptedText = aesDecryptString(cipherText, key);
NSLog(@"%@", decryptedText);
测试结果：
2017-08-07 17:04:07.346 AES加解密[1936:131257] BOtqpCDe2AcRw2sbt4+F9w==
2017-08-07 17:04:07.348 AES加解密[1936:131257] 战狼2
Java端：
一定要记得导入javabase64-1.3.1
import java.security.InvalidAlgorithmParameterException;
import java.security.InvalidKeyException;
import java.security.NoSuchAlgorithmException;
import java.util.Base64;
import java.util.Base64.Decoder;
import java.util.Base64.Encoder;
import javax.crypto.BadPaddingException;
import javax.crypto.Cipher;
import javax.crypto.IllegalBlockSizeException;
import javax.crypto.NoSuchPaddingException;
import javax.crypto.spec.IvParameterSpec;
import javax.crypto.spec.SecretKeySpec;
import java.io.UnsupportedEncodingException;
public class AESCipher {
private static final String IV_STRING = "A-16-Byte-String";
private static final String charset = "UTF-8";
public static String aesEncryptString(String content, String key) throws InvalidKeyException, NoSuchAlgorithmException, NoSuchPaddingException, InvalidAlgorithmParameterException, IllegalBlockSizeException, BadPaddingException, UnsupportedEncodingException {
byte[] contentBytes = content.getBytes(charset);
byte[] keyBytes = key.getBytes(charset);
byte[] encryptedBytes = aesEncryptBytes(contentBytes, keyBytes);
Encoder encoder = Base64.getEncoder();
return encoder.encodeToString(encryptedBytes);
}
public static String aesDecryptString(String content, String key) throws InvalidKeyException, NoSuchAlgorithmException, NoSuchPaddingException, InvalidAlgorithmParameterException, IllegalBlockSizeException, BadPaddingException, UnsupportedEncodingException {
Decoder decoder = Base64.getDecoder();
byte[] encryptedBytes = decoder.decode(content);
byte[] keyBytes = key.getBytes(charset);
byte[] decryptedBytes = aesDecryptBytes(encryptedBytes, keyBytes);
return new String(decryptedBytes, charset);
}
public static byte[] aesEncryptBytes(byte[] contentBytes, byte[] keyBytes) throws NoSuchAlgorithmException, NoSuchPaddingException, InvalidKeyException, InvalidAlgorithmParameterException, IllegalBlockSizeException, BadPaddingException, UnsupportedEncodingException {
return cipherOperation(contentBytes, keyBytes, Cipher.ENCRYPT_MODE);
}
public static byte[] aesDecryptBytes(byte[] contentBytes, byte[] keyBytes) throws NoSuchAlgorithmException, NoSuchPaddingException, InvalidKeyException, InvalidAlgorithmParameterException, IllegalBlockSizeException, BadPaddingException, UnsupportedEncodingException {
return cipherOperation(contentBytes, keyBytes, Cipher.DECRYPT_MODE);
}
private static byte[] cipherOperation(byte[] contentBytes, byte[] keyBytes, int mode) throws UnsupportedEncodingException, NoSuchAlgorithmException, NoSuchPaddingException, InvalidKeyException, InvalidAlgorithmParameterException, IllegalBlockSizeException, BadPaddingException {
SecretKeySpec secretKey = new SecretKeySpec(keyBytes, "AES");
byte[] initParam = IV_STRING.getBytes(charset);
IvParameterSpec ivParameterSpec = new IvParameterSpec(initParam);
Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
cipher.init(mode, secretKey, ivParameterSpec);
return cipher.doFinal(contentBytes);
}
}
测试：
String key = "16-Bytes--String16-Bytes--String";
String encryptStr = AESCipher.aesEncryptString("战狼2", key);
System.out.println(encryptStr);
String decryptStr = AESCipher.aesDecryptString(encryptStr, key);
System.out.println(decryptStr);
结果：
BOtqpCDe2AcRw2sbt4+F9w==
战狼2
两端之间的通信：
由上面测试结果可以看出，相同的加密规则，相同的加密内容，加密之后的结果是相同的。所以无论是iOS端加密，Java端解密 还是Java端加密，iOS端解密，都是可以实现的。
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