iOS之AES加密解密

//AES加密解密
#import <CommonCrypto/CommonCrypto.h>
#import <CommonCrypto/CommonDigest.h>

//AES128位加密 base64編碼 注：kCCKeySizeAES128點進去可以更換256位加密
-(NSString *)AES128Encrypt:(NSString *)plainText key:(NSString *)key
{
    char keyPtr[kCCKeySizeAES128+1];//
    memset(keyPtr, 0, sizeof(keyPtr));
    [key getCString:keyPtr maxLength:sizeof(keyPtr) encoding:NSUTF8StringEncoding];
    
    NSData* data = [plainText dataUsingEncoding:NSUTF8StringEncoding];
    NSUInteger dataLength = [data length];
    
    size_t bufferSize = dataLength + kCCBlockSizeAES128;
    void *buffer = malloc(bufferSize);
    size_t numBytesEncrypted = 0;
    CCCryptorStatus cryptStatus = CCCrypt(kCCEncrypt,
                                          kCCAlgorithmAES128,
                                          kCCOptionPKCS7Padding|kCCOptionECBMode,
                                          keyPtr,
                                          kCCBlockSizeAES128,
                                          NULL,
                                          [data bytes],
                                          dataLength,
                                          buffer,
                                          bufferSize,
                                          &numBytesEncrypted);
    if (cryptStatus == kCCSuccess) {
        NSData *resultData = [NSData dataWithBytesNoCopy:buffer length:numBytesEncrypted];
        
        NSString *stringBase64 = [resultData base64EncodedStringWithOptions:NSDataBase64EncodingEndLineWithLineFeed]; // base64格式的字符串
        return stringBase64;
        
    }
    free(buffer);
    return nil;
}

//解密
-(NSString *)AES128Decrypt:(NSString *)encryptText key:(NSString *)key
{
    char keyPtr[kCCKeySizeAES128 + 1];
    memset(keyPtr, 0, sizeof(keyPtr));
    [key getCString:keyPtr maxLength:sizeof(keyPtr) encoding:NSUTF8StringEncoding];
    
    NSData *data = [[NSData alloc] initWithBase64EncodedString:encryptText options:NSDataBase64DecodingIgnoreUnknownCharacters];//base64解碼
    
    NSUInteger dataLength = [data length];
    size_t bufferSize = dataLength + kCCBlockSizeAES128;
    void *buffer = malloc(bufferSize);
    
    size_t numBytesCrypted = 0;
    CCCryptorStatus cryptStatus = CCCrypt(kCCDecrypt,
                                          kCCAlgorithmAES128,
                                          kCCOptionPKCS7Padding|kCCOptionECBMode,
                                          keyPtr,
                                          kCCBlockSizeAES128,
                                          NULL,
                                          [data bytes],
                                          dataLength,
                                          buffer,
                                          bufferSize,
                                          &numBytesCrypted);
    if (cryptStatus == kCCSuccess) {
        NSData *resultData = [NSData dataWithBytesNoCopy:buffer length:numBytesCrypted];
        
        return [[NSString alloc] initWithData:resultData encoding:NSUTF8StringEncoding];
    }
    free(buffer);
    return nil;
}