objective-c - 在 iOS 上使用 CommonCrypto 的 PBKDF2

Question

我正在尝试使用CommonCrypto生成密钥，PBKDF2但我似乎无法导入CommonCrypto/CommonKeyDerivation.h，我只是找不到它的错误。

有任何想法吗？

编辑：我可能应该提到我已经添加了安全框架，我可以导入所有其他CommonCrypto标头。

Answer 1

这是我生成 AES256 密钥的方式。唯一有趣的是，我让 CommonCrypto 为我估算要使用多少轮。这似乎很简单。

#import <CommonCrypto/CommonKeyDerivation.h>

...

// Makes a random 256-bit salt
- (NSData*)generateSalt256 {
    unsigned char salt[32];
    for (int i=0; i<32; i++) {
        salt[i] = (unsigned char)arc4random();
    }
    return [NSData dataWithBytes:salt length:32];
}

...

// Make keys!
NSString* myPass = @"MyPassword1234";
NSData* myPassData = [myPass dataUsingEncoding:NSUTF8StringEncoding];
NSData* salt = [self generateSalt256];

// How many rounds to use so that it takes 0.1s ?
int rounds = CCCalibratePBKDF(kCCPBKDF2, myPassData.length, salt.length, kCCPRFHmacAlgSHA256, 32, 100);

// Open CommonKeyDerivation.h for help
unsigned char key[32];
CCKeyDerivationPBKDF(kCCPBKDF2, myPassData.bytes, myPassData.length, salt.bytes, salt.length, kCCPRFHmacAlgSHA256, rounds, key, 32);

Answer 2

1. 将此库添加到您的项目 libcommonCrypto.dylib
2. #import 到哈希键生成类。
3. 使用以下代码生成哈希键。

这是我使用的代码：

// Salt data getting from salt string.
NSData *saltData = [@"Salt String" dataUsingEncoding:NSUTF8StringEncoding];

// Data of String to generate Hash key(hexa decimal string).
NSData *passwordData = [@"Hash key generated string" dataUsingEncoding:NSUTF8StringEncoding];

// Hash key (hexa decimal) string data length.
NSMutableData *hashKeyData = [NSMutableData dataWithLength:CC_SHA1_DIGEST_LENGTH];

// Key Derivation using PBKDF2 algorithm.
int result = CCKeyDerivationPBKDF(kCCPBKDF2, passwordData.bytes, passwordData.length, saltData.bytes, saltData.length, kCCPRFHmacAlgSHA1, 1000, hashKeyData.mutableBytes, hashKeyData.length);

// Hexa decimal or hash key string from hash key data.
NSString *hexDecimalString = hashKeyData.description;

NSLog(@"Hexa decimal string:%@", hexDecimalString);

Answer 3

你在为 iOS5 构建吗？或更早的版本？

头文件中定义的APICCKeyDerivationPBKDF和CCCalibratePBKDF仅在 IOS5（或 OSX 10.7）及更高版本上可用。

您可以通过在终端窗口中执行此操作来确保文件存在：

$ find /Developer/ -name CommonKeyDerivation.h
/Developer//Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS5.0.sdk/usr/include/CommonCrypto/CommonKeyDerivation.h
/Developer//Platforms/iPhoneSimulator.platform/Developer/SDKs/iPhoneSimulator5.0.sdk/usr/include/CommonCrypto/CommonKeyDerivation.h
/Developer//SDKs/MacOSX10.7.sdk/usr/include/CommonCrypto/CommonKeyDerivation.h