swift2 – 如何在Swift 2和3中使用CommonCrypto for PBKDF2

我试图使用CommonCrypto在 Swift 2中使用PBKDF2散列密码,因为它具有高性能,并且由于它是开源的

我已经设法使用模块映射让CommonCrypto在Swift中工作,但有人可以告诉我使用CommonCrypto在Swift 2中使用PBKDF2进行散列的代码

func pbkdf2(hash :CCPBKDFAlgorithm, password: String, salt: [UInt8], keyCount: Int, rounds: UInt32!) -> [UInt8]! {
    let derivedKey   = [UInt8](count:keyCount, repeatedValue:0)
    let passwordData = password.dataUsingEncoding(NSUTF8StringEncoding)!

    let derivationStatus = CCKeyDerivationPBKDF(
        CCPBKDFAlgorithm(kCCPBKDF2),
        UnsafePointer<Int8>(passwordData.bytes), passwordData.length,
        UnsafePointer<UInt8>(salt), salt.count,
        CCPseudoRandomAlgorithm(hash),
        rounds,
        UnsafeMutablePointer<UInt8>(derivedKey),
        derivedKey.count)


    if (derivationStatus != 0) {
        print("Error: \(derivationStatus)")
        return nil;
    }

    return derivedKey
}

hash是哈希类型,例如kCCPRFHmacAlgSHA1,kCCPRFHmacAlgSHA256,kCCPRFHmacAlgSHA512.

日落文档部分的示例：

基于密码的密钥派生2(Swift 3)

基于密码的密钥派生既可用于从密码文本中导出加密密钥,也可用于保存密码以进行身份​​验证.

可以使用几种哈希算法,包括SHA1,SHA256,SHA512,这些算法由此示例代码提供.

rounds参数用于使计算变慢,以便攻击者必须在每次尝试上花费大量时间.典型的延迟值在100ms到500ms之间,如果有不可接受的性能,可以使用更短的值.

此示例需要Common Crypto
有必要为项目建立一个桥接头：
    #import< CommonCrypto / CommonCrypto.h>
    将Security.framework添加到项目中.

参数：

password     password String  
salt         salt Data  
keyByteCount number of key bytes to generate
rounds       Iteration rounds

returns      Derived key


func pbkdf2SHA1(password: String, salt: Data, keyByteCount: Int, rounds: Int) -> Data? {
    return pbkdf2(hash:CCPBKDFAlgorithm(kCCPRFHmacAlgSHA1), password:password, salt:salt, keyByteCount:keyByteCount, rounds:rounds)
}

func pbkdf2SHA256(password: String, salt: Data, keyByteCount: Int, rounds: Int) -> Data? {
    return pbkdf2(hash:CCPBKDFAlgorithm(kCCPRFHmacAlgSHA256), password:password, salt:salt, keyByteCount:keyByteCount, rounds:rounds)
}

func pbkdf2SHA512(password: String, salt: Data, keyByteCount: Int, rounds: Int) -> Data? {
    return pbkdf2(hash:CCPBKDFAlgorithm(kCCPRFHmacAlgSHA512), password:password, salt:salt, keyByteCount:keyByteCount, rounds:rounds)
}

func pbkdf2(hash :CCPBKDFAlgorithm, password: String, salt: Data, keyByteCount: Int, rounds: Int) -> Data? {
    let passwordData = password.data(using:String.Encoding.utf8)!
    var derivedKeyData = Data(repeating:0, count:keyByteCount)

    let derivationStatus = derivedKeyData.withUnsafeMutableBytes {derivedKeyBytes in
        salt.withUnsafeBytes { saltBytes in

            CCKeyDerivationPBKDF(
                CCPBKDFAlgorithm(kCCPBKDF2),
                password, passwordData.count,
                saltBytes, salt.count,
                hash,
                UInt32(rounds),
                derivedKeyBytes, derivedKeyData.count)
        }
    }
    if (derivationStatus != 0) {
        print("Error: \(derivationStatus)")
        return nil;
    }

    return derivedKeyData
}

用法示例：

let password     = "password"
//let salt       = "saltData".data(using: String.Encoding.utf8)!
let salt         = Data(bytes: [0x73, 0x61, 0x6c, 0x74, 0x44, 0x61, 0x74, 0x61])
let keyByteCount = 16
let rounds       = 100000

let derivedKey = pbkdf2SHA1(password:password, salt:salt, keyByteCount:keyByteCount, rounds:rounds)
print("derivedKey (SHA1): \(derivedKey! as NSData)")

示例输出：

derivedKey (SHA1): <6b9d4fa3 0385d128 f6d196ee 3f1d6dbf>

基于密码的密钥派生校准

此示例需要Common Crypto
有必要为项目建立一个桥接头：

#import <CommonCrypto/CommonCrypto.h>

将Security.framework添加到项目中.

确定当前平台上特定延迟使用的PRF轮次数.

有几个参数默认为不应对圆计数产生实质影响的代表值.

password Sample password.  
salt     Sample salt.  
msec     Targeted duration we want to achieve for a key derivation.

returns  The number of iterations to use for the desired processing time.

Password Based Key Derivation Calibration (Swift 3)

func pbkdf2SHA1Calibrate(password: String, salt: Data, msec: Int) -> UInt32 {
    let actualRoundCount: UInt32 = CCCalibratePBKDF(
        CCPBKDFAlgorithm(kCCPBKDF2),
        password.utf8.count,
        salt.count,
        CCPseudoRandomAlgorithm(kCCPRFHmacAlgSHA1),
        kCCKeySizeAES256,
        UInt32(msec));
    return actualRoundCount
}

用法示例：

let saltData       = Data(bytes: [0x73, 0x61, 0x6c, 0x74, 0x44, 0x61, 0x74, 0x61])
let passwordString = "password"
let delayMsec      = 100

let rounds = pbkdf2SHA1Calibrate(password:passwordString, salt:saltData, msec:delayMsec)
print("For \(delayMsec) msec delay, rounds: \(rounds)")

示例输出：

For 100 msec delay, rounds: 93457

Password Based Key Derivation Calibration (Swift 2.3)

func pbkdf2SHA1Calibrate(password:String, salt:[UInt8], msec:Int) -> UInt32 {
    let actualRoundCount: UInt32 = CCCalibratePBKDF(
        CCPBKDFAlgorithm(kCCPBKDF2),
        password.utf8.count,
        salt.count,
        CCPseudoRandomAlgorithm(kCCPRFHmacAlgSHA1),
        kCCKeySizeAES256,
        UInt32(msec));
    return actualRoundCount
}

用法示例：

let saltData       = [UInt8]([0x73, 0x61, 0x6c, 0x74, 0x44, 0x61, 0x74, 0x61])
let passwordString = "password"
let delayMsec      = 100

let rounds = pbkdf2SHA1Calibrate(passwordString, salt:saltData, msec:delayMsec)
print("For \(delayMsec) msec delay, rounds: \(rounds)")