swift实现AES解密

原来的加密解密是用java写的，用在安卓系统上。现在要用在iOS系统上，所以从服务器上下载过来的加密文件要用swift来实现其的解密方法。

具体过程如下：

给NSData增加一个类目，NSData+AES

NSData+AES.h

- (NSData *)AES128DecryptWithKey:(NSString *)key iv:(NSData *)iv;

NSData+AES.m

- (NSData *)AES128operation:(CCOperation)operation key:(NSString *)key iv:(NSData *)iv

{

char keyPtr[kCCKeySizeAES128 + 1];

bzero(keyPtr, sizeof(keyPtr));

[key getCString:keyPtr maxLength:sizeof(keyPtr) encoding:NSUTF8StringEncoding];

Byte key2[] = {0xF0,0x1E,0x02,0xB2,0xE3,0xC9,0x7A,0x43,0xFD,0xFE,0x31,0x1A,0x2B,0xA4,0x4C,0x60};

// IV

Byte ivPtr[kCCBlockSizeAES128 + 1];

bzero(ivPtr, sizeof(ivPtr));

//[iv getCString:ivPtr maxLength:sizeof(ivPtr) encoding:NSUTF8StringEncoding];

[iv getBytes:&ivPtr length:16];

size_t bufferSize = [self length] + kCCBlockSizeAES128;

void *buffer = malloc(bufferSize);

size_t numBytesEncrypted = 0;

CCCryptorStatus cryptorStatus = CCCrypt(operation, kCCAlgorithmAES128, kCCOptionPKCS7Padding,

key2, kCCKeySizeAES128,

ivPtr,

[self bytes], [self length],

buffer, bufferSize,

&numBytesEncrypted);

if(cryptorStatus == kCCSuccess){

NSLog(@"Success");

return [NSData dataWithBytesNoCopy:buffer length:numBytesEncrypted];

}else{

NSLog(@"Error");

}

free(buffer);

return nil;

}