aes加密

+(NSData)encryptAESData:(NSString)string withKey:(NSString *)key {
//将nsstring转化为nsdata
NSData *data = [string dataUsingEncoding:NSUTF8StringEncoding];
//使用密码对nsdata进行加密
NSData *encryptedData = [data AES256EncryptWithKey:key];
return encryptedData;
}

• (NSData *)AES256EncryptWithKey:(NSString *)key {//加密
  char keyPtr[kCCKeySizeAES256+1];
  bzero(keyPtr, sizeof(keyPtr));
  [key getCString:keyPtr maxLength:sizeof(keyPtr) encoding:NSUTF8StringEncoding];
  NSUInteger dataLength = [self length];
  size_t bufferSize = dataLength + kCCBlockSizeAES128;
  void *buffer = malloc(bufferSize);
  size_t numBytesEncrypted = 0;
  CCCryptorStatus cryptStatus = CCCrypt(kCCEncrypt, kCCAlgorithmAES128,
  kCCOptionPKCS7Padding | kCCOptionECBMode,
  keyPtr, kCCBlockSizeAES128,
  NULL,
  [self bytes], dataLength,
  buffer, bufferSize,
  &numBytesEncrypted);
  if (cryptStatus == kCCSuccess) {
  return [NSData dataWithBytesNoCopy:buffer length:numBytesEncrypted];
  }
  free(buffer);
  return nil;
  }
  解密
• (NSData *)AES256DecryptWithKey:(NSString *)key {//解密
  char keyPtr[kCCKeySizeAES256+1];
  bzero(keyPtr, sizeof(keyPtr));
  [key getCString:keyPtr maxLength:sizeof(keyPtr) encoding:NSUTF8StringEncoding];
  NSUInteger dataLength = [self length];
  size_t bufferSize = dataLength + kCCBlockSizeAES128;
  void *buffer = malloc(bufferSize);
  size_t numBytesDecrypted = 0;
  CCCryptorStatus cryptStatus = CCCrypt(kCCDecrypt, kCCAlgorithmAES128,
  kCCOptionPKCS7Padding | kCCOptionECBMode,
  keyPtr, kCCBlockSizeAES128,
  NULL,
  [self bytes], dataLength,
  buffer, bufferSize,
  &numBytesDecrypted);
  if (cryptStatus == kCCSuccess) {
  return [NSData dataWithBytesNoCopy:buffer length:numBytesDecrypted];
  }
  free(buffer);
  return nil;
  }