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我一直在努力使用 libsodium 中的 crypto_secretbox_easy() 加密/解密一些数据。我似乎找不到任何关于使用的好的文档。

我想从用户那里得到一个密码,用它来制作一个密钥,然后用它加密/解密数据。

我在下面发布的玩具代码的问题是 crypto_secretbox_open_easy() 从 verify_16.c 中返回 -1。有谁知道我在哪里可以找到显示如何使用此界面或可能出现什么问题的来源?谢谢!

 unsigned char * cipher;
 unsigned char * decoded;
 unsigned char * message;
 unsigned long long message_len = 32;
 size_t noncelen = sizeof(char) * crypto_secretbox_noncebytes();
 size_t keylen = sizeof(char) * crypto_secretbox_keybytes();
 unsigned char * nonce = calloc(noncelen, noncelen);
 unsigned char * key = calloc(keylen, keylen);

 message = calloc(32*sizeof(char), sizeof(char) * 32);
 cipher = calloc(32*sizeof(char), sizeof(char) * 32);
 decoded = calloc(32*sizeof(char), sizeof(char) * 32);

 crypto_secretbox_easy((unsigned char *)cipher, (const unsigned char *)message, 
                      message_len, nonce, key);

 crypto_secretbox_open_easy((unsigned char *)decoded, (const unsigned char *) cipher, 
                            message_len, nonce, key);
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2 回答 2

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给 crypto_secretbox_open_easy() 的长度应该是经过身份验证/加密的消息的长度,它不是 message_len,因为添加了身份验证标签。这个标签的长度是 crypto_box_MACBYTES。

于 2014-03-17T20:56:53.933 回答
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- (NSData *)encrypt:(NSData *)data nonce:(NSData *)nonce key:(NSData *)key error:(NSError **)error {
  if (!nonce || [nonce length] != NASecretBoxNonceSize) {
    if (error) *error = NAError(NAErrorCodeInvalidNonce, @"Invalid nonce");
    return nil;
  }

  if (!data) {
    if (error) *error = NAError(NAErrorCodeInvalidData, @"Invalid data");
    return nil;
  }

  if (!key || [key length] != NASecretBoxKeySize) {
    if (error) *error = NAError(NAErrorCodeInvalidKey, @"Invalid key");
    return nil;
  }

  // Add space for authentication tag of size MACBYTES
  NSMutableData *outData = [NSMutableData dataWithLength:[data length] + NASecretBoxMACSize];

  int retval = crypto_secretbox_easy([outData mutableBytes],
                                     [data bytes], [data length],
                                     [nonce bytes],
                                     [key bytes]);

  if (retval != 0) {
    if (error) *error = NAError(NAErrorCodeFailure, @"Encrypt (secret box) failed");
    return nil;
  }

  return outData;
}

- (NSData *)decrypt:(NSData *)data nonce:(NSData *)nonce key:(NSData *)key error:(NSError **)error {
  if (!nonce || [nonce length] != NASecretBoxNonceSize) {
    if (error) *error = NAError(NAErrorCodeInvalidNonce, @"Invalid nonce");
    return nil;
  }

  if (!data) {
    if (error) *error = NAError(NAErrorCodeInvalidData, @"Invalid data");
    return nil;
  }

  if (!key || [key length] != NASecretBoxKeySize) {
    if (error) *error = NAError(NAErrorCodeInvalidKey, @"Invalid key");
    return nil;
  }

  __block int retval = -1;
  NSMutableData *outData = NAData(self.secureDataEnabled, data.length, ^(void *bytes, NSUInteger length) {
    retval = crypto_secretbox_open_easy(bytes,
                                        [data bytes], [data length],
                                        [nonce bytes], [key bytes]);
  });
  if (retval != 0) {
    if (error) *error = NAError(NAErrorCodeVerificationFailed, @"Verification failed");
    return nil;
  }

  // Remove MAC bytes from data
  return [outData na_truncate:NASecretBoxMACSize];
}
于 2018-08-08T15:27:39.677 回答