OC-AES加密/解密

#import <Foundation/Foundation.h>

@interface NSObject (AESUtil)
/**
 * AES加密
 */
+ (NSString *)aesEncrypt:(NSString *)sourceStr;
 
/**
 * AES解密
 */
+ (NSString *)aesDecrypt:(NSString *)secretStr;
@end

#import "NSObject+AESUtil.h"
#import <CommonCrypto/CommonDigest.h>
#import <CommonCrypto/CommonCryptor.h>

// 秘钥key
const NSString * AESKey = @"abcdefghABCDEFGH";

@implementation NSObject (AESUtil)

+ (NSString *)aesEncrypt:(NSString *)sourceStr{
    if (!sourceStr) {
        return nil;
    }
    char keyPtr[kCCKeySizeAES256 + 1];
    bzero(keyPtr, sizeof(keyPtr));
    [AESKey getCString:keyPtr maxLength:sizeof(keyPtr) encoding:NSUTF8StringEncoding];
     
    NSData * sourceData = [sourceStr dataUsingEncoding:NSUTF8StringEncoding];
    NSUInteger dataLength = [sourceData length];
    size_t buffersize = dataLength + kCCBlockSizeAES128;
    void * buffer = malloc(buffersize);
    size_t numBytesEncrypted = 0;
    CCCryptorStatus cryptStatus = CCCrypt(kCCEncrypt, kCCAlgorithmAES128, kCCOptionPKCS7Padding | kCCOptionECBMode, keyPtr, kCCBlockSizeAES128, NULL, [sourceData bytes], dataLength, buffer, buffersize, &numBytesEncrypted);
     
    if (cryptStatus == kCCSuccess) {
        NSData * encryptData = [NSData dataWithBytesNoCopy:buffer length:numBytesEncrypted];
        //对加密后的二进制数据进行base64转码
        return [encryptData base64EncodedStringWithOptions:NSDataBase64EncodingEndLineWithLineFeed];
    } else {
        free(buffer);
        return nil;
    }
}
 
+ (NSString *)aesDecrypt:(NSString *)secretStr{
    if (!secretStr) {
        return nil;
    }
    //先对加密的字符串进行base64解码
    NSData * decodeData = [[NSData alloc] initWithBase64EncodedString:secretStr options:NSDataBase64DecodingIgnoreUnknownCharacters];
     
    char keyPtr[kCCKeySizeAES256 + 1];
    bzero(keyPtr, sizeof(keyPtr));
    [AESKey getCString:keyPtr maxLength:sizeof(keyPtr) encoding:NSUTF8StringEncoding];
     
    NSUInteger dataLength = [decodeData length];
    size_t bufferSize = dataLength + kCCBlockSizeAES128;
    void * buffer = malloc(bufferSize);
    size_t numBytesDecrypted = 0;
    CCCryptorStatus cryptStatus = CCCrypt(kCCDecrypt, kCCAlgorithmAES128, kCCOptionPKCS7Padding | kCCOptionECBMode, keyPtr, kCCBlockSizeAES128, NULL, [decodeData bytes], dataLength, buffer, bufferSize, &numBytesDecrypted);
    if (cryptStatus == kCCSuccess) {
        NSData * data = [NSData dataWithBytesNoCopy:buffer length:numBytesDecrypted];
        NSString * result = [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding];
        return result;
    } else {
        free(buffer);
        return nil;
    }
}
@end