iOS系统方法进行AES对称加密

此方法采用kCCAlgorithmAES128，kCCOptionPKCS7Padding，kCCOptionECBMode，kCCBlockSizeAES128模式。如果另有其他模式需求加上即可！

废话不多说，直接上代码：

头文件：

[objc] view plaincopyprint?

1. #import <Foundation/Foundation.h>   

2. #import <CommonCrypto/CommonCryptor.h>

    
3. @class NSString;  
4.   
5. @interface NSData (Encryption)  
6.   
7. - (NSData *)AES256ParmEncryptWithKey:(NSString *)key;   //加密  
8. - (NSData *)AES256ParmDecryptWithKey:(NSString *)key;   //解密  
9.   
10. @end  

.m实现文件：

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1. #import "Encryption.h"  
2. #import <CommonCrypto/CommonCryptor.h>  
3.   
4. @implementation NSData (Encryption)  
5.   
6. - (NSData *)AES256ParmEncryptWithKey:(NSString *)key   //加密  
7. {  
8.     char keyPtr[kCCKeySizeAES256+1];  
9.     bzero(keyPtr, sizeof(keyPtr));  
10.     [key getCString:keyPtr maxLength:sizeof(keyPtr) encoding:NSUTF8StringEncoding];  
11.     NSUInteger dataLength = [self length];  
12.     size_t bufferSize = dataLength + kCCBlockSizeAES128;  
13.     voidvoid *buffer = malloc(bufferSize);  
14.     size_t numBytesEncrypted = 0;  
15.     CCCryptorStatus cryptStatus = CCCrypt(kCCEncrypt, kCCAlgorithmAES128,  
16.                                           kCCOptionPKCS7Padding | kCCOptionECBMode,  
17.                                           keyPtr, kCCBlockSizeAES128,  
18.                                           NULL,  
19.                                           [self bytes], dataLength,  
20.                                           buffer, bufferSize,  
21.                                           &numBytesEncrypted);  
22.     if (cryptStatus == kCCSuccess) {  
23.         return [NSData dataWithBytesNoCopy:buffer length:numBytesEncrypted];  
24.     }  
25.     free(buffer);  
26.     return nil;  
27. }  
28.   
29.   
30. - (NSData *)AES256ParmDecryptWithKey:(NSString *)key   //解密  
31. {  
32.     char keyPtr[kCCKeySizeAES256+1];  
33.     bzero(keyPtr, sizeof(keyPtr));  
34.     [key getCString:keyPtr maxLength:sizeof(keyPtr) encoding:NSUTF8StringEncoding];  
35.     NSUInteger dataLength = [self length];  
36.     size_t bufferSize = dataLength + kCCBlockSizeAES128;  
37.     voidvoid *buffer = malloc(bufferSize);  
38.     size_t numBytesDecrypted = 0;  
39.     CCCryptorStatus cryptStatus = CCCrypt(kCCDecrypt, kCCAlgorithmAES128,  
40.                                           kCCOptionPKCS7Padding | kCCOptionECBMode,  
41.                                           keyPtr, kCCBlockSizeAES128,  
42.                                           NULL,  
43.                                           [self bytes], dataLength,  
44.                                           buffer, bufferSize,  
45.                                           &numBytesDecrypted);  
46.     if (cryptStatus == kCCSuccess) {  
47.         return [NSData dataWithBytesNoCopy:buffer length:numBytesDecrypted];  
48.     }  
49.     free(buffer);  
50.     return nil;  
51. }