使用CommonCrypto / CommonHMAC加密一些数据，并始终返回null

问题描述

我尝试使用密钥 keyData 加密 clearTextData 。我确实检查了这两个值是否有效并经过。

I tried the following to encrypt the clearTextData using the key keyData. And I did check to make sure that both of those values are valid and going through.

NSData *keyData = [PRIVATE_KEY dataUsingEncoding:NSUTF8StringEncoding];
NSData *clearTextData = [data dataUsingEncoding:NSUTF8StringEncoding];

uint8_t digest[CC_SHA1_DIGEST_LENGTH] = {0};

CCHmacContext hmacContext;
CCHmacInit(&hmacContext, kCCHmacAlgSHA1, keyData.bytes, keyData.length);
CCHmacUpdate(&hmacContext, clearTextData.bytes, clearTextData.length);
CCHmacFinal(&hmacContext, digest);

NSData *out = [NSData dataWithBytes:digest length:CC_SHA1_DIGEST_LENGTH];

NSLog(@"encrypted data: %@", [NSString stringWithUTF8String:[out bytes]]);

日志总是回来说加密数据：（null）

任何想法？

*更新*

以下是我传递的关键字和数据的示例：

Here are examples of the key and data that I am passing:

data：
{data：lala，pubKey：75948458，sig：val}

data: {"data":"lala","pubKey":"75948458","sig":"val"}

推荐答案

来自加密的此数据是数据，并尝试将其转换为字符串编码失败。您正在指定UTF8编码，我也尝试过UTF32编码，并且失败。只需记录返回的数据，因为这些十六进制值比字符串表示更有利。

This data from the crypto is data and attempting to turn it into string is failing on the encoding. You are specifying UTF8 encoding and I have also tried UTF32 encoding and that fails as well. Just log the data returned as those hex values are more beneficial than a string representation.

如果你仍然希望看到尽可能多的字符串，你可以这样做

If you would still like to see as much as the string as possible you can do this.

NSData *output = [NSData dataWithBytes:digest length:CC_SHA1_DIGEST_LENGTH];

    //This is useful
NSLog(@"encrypted data: %@", output);

    //Not useful but you may be able to visualize some of the string
char *outstr = malloc(sizeof(char) * (CC_SHA1_DIGEST_LENGTH + 1));
memcpy(outstr, [output bytes], CC_SHA1_DIGEST_LENGTH);
outstr[CC_SHA1_DIGEST_LENGTH] = 0;
NSLog(@"encrypted data string: %s", outstr);
free(outstr);

我也在以下行中取得了一些成功（打印与上述不同的字符串）

And I also had some success with the following line.(Prints a different string than above)

NSLog(@"encrypted data: %@", [[[NSString alloc] initWithData:output encoding:NSISOLatin2StringEncoding] autorelease]);

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