2014-10-02 34 views
2

我使用RNCryptor成功地在iOS中加密/解密数据。RNCryptor:获取公钥为NSString

我想获得公钥发送到服务器,所以它可以加密一些数据。

NSString *saltString = @"salt'n'peppa"; 
NSData *salt = [saltString dataUsingEncoding:NSUTF8StringEncoding]; 
NSData *key = [RNCryptor keyForPassword:password 
            salt:salt 
           settings:kRNCryptorAES256Settings.keySettings]; 

此时,key中有一些数据。不过,我似乎无法工作,如何将公钥作为一个字符串:

NSString *publicKey = [[NSString alloc] initWithData:key encoding:NSUTF8StringEncoding]; 

我试过不同的编码,但似乎没有任何工作。

这里是RNCryptor的keyForPassword方法:

+ (NSData *)keyForPassword:(NSString *)password salt:(NSData *)salt settings:(RNCryptorKeyDerivationSettings)keySettings 
{ 
    NSMutableData *derivedKey = [NSMutableData dataWithLength:keySettings.keySize]; 

    // See Issue #77. V2 incorrectly calculated key for multi-byte characters. 
    NSData *passwordData; 
    if (keySettings.hasV2Password) { 
    passwordData = [NSData dataWithBytes:[password UTF8String] length:[password length]]; 
    } 
    else { 
    passwordData = [password dataUsingEncoding:NSUTF8StringEncoding]; 
    } 

    // Use the built-in PBKDF2 if it's available. Otherwise, we have our own. Hello crazy function pointer. 
    int result; 
    int (*PBKDF)(CCPBKDFAlgorithm algorithm, const char *password, size_t passwordLen, 
       const uint8_t *salt, size_t saltLen, 
       CCPseudoRandomAlgorithm prf, uint rounds, 
       uint8_t *derivedKey, size_t derivedKeyLen); 

    PBKDF = CCKeyDerivationPBKDF ?: RN_CCKeyDerivationPBKDF; 

    result = PBKDF(keySettings.PBKDFAlgorithm,   // algorithm 
       passwordData.bytes,     // password 
       passwordData.length,    // passwordLength 
       salt.bytes,       // salt 
       salt.length,      // saltLen 
       keySettings.PRF,     // PRF 
       keySettings.rounds,     // rounds 
       derivedKey.mutableBytes,   // derivedKey 
       derivedKey.length);     // derivedKeyLen 

    // Do not log password here 
    NSAssert(result == kCCSuccess, @"Unable to create AES key for password: %d", result); 

    return derivedKey; 
} 

我得到我做得majorly错误的,因为谷歌搜索的感觉出现很少。

回答

4

密钥不是字符串,而是数据。只是一系列随机(字节)的字节。将其转换为字符串发送到服务器的唯一方法是编码字节。一种常用的方法是使用base 64编码。然后,服务器可以将基础64编码的字符串转换回密钥的原始字节。

+0

如果服务器运行PHP,您可以通过提供'NSData'对象作为POST数据发送原始字节,然后使用'file_get_contents('php:// input')'在PHP中读取它。这种方式不需要base64编码。 PHP的字符串数据类型比'NSString'更接近'NSData'(尽管这可能会在PHP的未来版本中发生变化......) – 2014-10-02 05:30:17

+0

@maddy非常感谢。这很有道理。 – 2014-10-02 10:45:13

+0

@AbhiBeckert我没有使用PHP,但多数民众赞成知道。我会记住它 – 2014-10-02 10:46:01