簡介:AES是一種對(duì)稱加密方式，旨在取代DES成為廣泛使用的標(biāo)準(zhǔn)。雖然語言不同，但是AES的算法是相同的。
關(guān)于AES的各種參數(shù)請(qǐng)參考下面文章(一定要認(rèn)真閱讀，不然就沒辦法按照自己的想法進(jìn)行加密解密)：AES加密 - iOS與Java的同步實(shí)現(xiàn)
思路：
先說一下我的想法，iOS端加密由Java解密，Java加密由iOS解密，加密模式采取CBC，密鑰長度為256位，初始向量（相當(dāng)于是加密解密規(guī)則）為32位，這個(gè)是要對(duì)應(yīng)密鑰長度的。
難點(diǎn)：
1、Java對(duì)于大于128bits的是不支持的，我們需要將JDK中的local_policy.jar US_export_policy.jar用這里的jar包替換掉，我的mac電腦，JDK路徑是資源庫/Java/JavaVirtualMachines/jdk1.8.0_111.jdk/Contents/Home/jre/libsecurity
替換的jar包
這樣Java才會(huì)支持256位的密鑰加密。
2、iOS端的kKeySize改為
kCCKeySizeAES256。3、兩端的key（加密解密規(guī)則）設(shè)置成32位字符串。
實(shí)現(xiàn)：
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);
}
先自行測(cè)試一下：
NSString *plainText = @"戰(zhàn)狼2";
//32位key，加解密規(guī)則
NSString *key = @"16-Bytes--String16-Bytes--String";
NSString *cipherText = aesEncryptString(plainText, key);
NSLog(@"%@", cipherText);
NSString *decryptedText = aesDecryptString(cipherText, key);
NSLog(@"%@", decryptedText);
測(cè)試結(jié)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] 戰(zhàn)狼2
Java端：
一定要記得導(dǎo)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);
}
}
測(cè)試：
String key = "16-Bytes--String16-Bytes--String";
String encryptStr = AESCipher.aesEncryptString("戰(zhàn)狼2", key);
System.out.println(encryptStr);
String decryptStr = AESCipher.aesDecryptString(encryptStr, key);
System.out.println(decryptStr);
結(jié)果：
BOtqpCDe2AcRw2sbt4+F9w==
戰(zhàn)狼2
兩端之間的通信：
由上面測(cè)試結(jié)果可以看出，相同的加密規(guī)則，相同的加密內(nèi)容，加密之后的結(jié)果是相同的。所以無論是iOS端加密，Java端解密 還是Java端加密，iOS端解密，都是可以實(shí)現(xiàn)的。
