Swift：如何从Swift调用CCKeyDerivationPBKDF
我正在尝试从Swift调用CCKeyDerivationPBKDF。
我已经在Project-Bridging-Header.h中导入了所需的标头：
#import <CommonCrypto/CommonKeyDerivation.h>（顺便说一句，在我的项目中导入其他Objective C代码时，桥接头似乎正常工作）。
在Xcode中，我可以从.swift文件跳转到此处显示的定义：
int CCKeyDerivationPBKDF( 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)
最后，当我尝试像这样调用函数时：
let result = CCKeyDerivationPBKDF(CCPBKDFAlgorithm(kCCPBKDF2), NSString(password).UTF8String, size_t(passwordLength), UnsafePointer<UInt8>(salt.bytes), size_t(salt.length), CCPseudoRandomAlgorithm(kCCPRFHmacAlgSHA256), uint(actualRoundCount), UnsafeMutablePointer<UInt8>(derivedKey.mutableBytes), size_t(derivedKey.length));…我得到这个编译器错误：
无法使用类型为’（CCPBKDFAlgorithm，UnsafePointer，size_t，UnsafePointer，size_t，CCPseudoRandomAlgorithm，uint，UnsafeMutablePointer，size_t）的参数列表调用’init’
我相信所有强制转换都是正确的（实际上，编译器错误帮助我识别了每个参数的每个问题）-这使我认为编译器理解了我调用CCKeyDerivationPBKDF的意图。
但是，在所有其他强制转换错误消失之后，编译器感到困惑，并认为我正在尝试使用初始化程序构造一个类。
希望有人可以告诉我我的方式的错误。
（Xcode 6 beta 7）
根据要求，在上下文中提供完整代码：
class func generateAesKeyForPassword(password: String, salt: NSData, roundCount: UInt?, error: NSErrorPointer) -> (key: NSData, actualRoundCount: UInt)? {
let derivedKey = NSMutableData(length: kCCKeySizeAES256)
let passwordLength = size_t(password.lengthOfBytesUsingEncoding(NSUTF8StringEncoding))
var actualRoundCount: UInt
if roundCount != nil
{
actualRoundCount = roundCount!
}
else
{
actualRoundCount = UInt(CCCalibratePBKDF(CCPBKDFAlgorithm(kCCPBKDF2), passwordLength, UInt(salt.length), CCPseudoRandomAlgorithm(kCCPRFHmacAlgSHA256), UInt(derivedKey.length), UInt32(300) /* milliseconds */));
}
let result = CCKeyDerivationPBKDF(CCPBKDFAlgorithm(kCCPBKDF2), NSString(password).UTF8String, size_t(passwordLength), UnsafePointer<UInt8>(salt.bytes), size_t(salt.length), CCPseudoRandomAlgorithm(kCCPRFHmacAlgSHA256), uint(actualRoundCount), UnsafeMutablePointer<UInt8>(derivedKey.mutableBytes), size_t(derivedKey.length));
if result != 0
{
let errorDescription = "CCKeyDerivationPBKDF failed with error: '\(result)'"
error.memory = MyError(domain: ClientErrorType.errorDomain, code: Int(result), descriptionText: errorDescription)
return nil
}
return (NSData(data: derivedKey), actualRoundCount)
}
回答：
回答：
基于密码的密钥派生既可以用于从密码文本派生加密密钥，又可以保存密码以进行身份验证。
此示例代码提供了多种可用的哈希算法，包括SHA1，SHA256，SHA512。
rounds参数用于使计算变慢，因此攻击者将不得不在每次尝试上花费大量时间。典型的延迟值介于100ms至500ms之间，如果性能不可接受，则可以使用更短的值。
此示例需要通用加密
。必须在项目中具有桥接头：
#import <CommonCrypto/CommonCrypto.h>
将添加Security.framework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>回答：
参数类型和类对实例方法的微小更改，以进行测试。
func generateAesKeyForPassword(password: String, salt: NSData, roundCount: Int?, error: NSErrorPointer) -> (key: NSData, actualRoundCount: UInt32)?{
let nsDerivedKey = NSMutableData(length: kCCKeySizeAES256)
var actualRoundCount: UInt32
// Create Swift intermediates for clarity in function calls
let algorithm: CCPBKDFAlgorithm = CCPBKDFAlgorithm(kCCPBKDF2)
let prf: CCPseudoRandomAlgorithm = CCPseudoRandomAlgorithm(kCCPRFHmacAlgSHA256)
let saltBytes = UnsafePointer<UInt8>(salt.bytes)
let saltLength = size_t(salt.length)
let nsPassword = password as NSString
let nsPasswordPointer = UnsafePointer<Int8>(nsPassword.cStringUsingEncoding(NSUTF8StringEncoding))
let nsPasswordLength = size_t(nsPassword.lengthOfBytesUsingEncoding(NSUTF8StringEncoding))
var nsDerivedKeyPointer = UnsafeMutablePointer<UInt8>(nsDerivedKey.mutableBytes)
let nsDerivedKeyLength = size_t(nsDerivedKey.length)
let msec: UInt32 = 300
if roundCount != nil {
actualRoundCount = UInt32(roundCount!)
}
else {
actualRoundCount = CCCalibratePBKDF(
algorithm,
nsPasswordLength,
saltLength,
prf,
nsDerivedKeyLength,
msec);
}
let result = CCKeyDerivationPBKDF(
algorithm,
nsPasswordPointer, nsPasswordLength,
saltBytes, saltLength,
prf, actualRoundCount,
nsDerivedKeyPointer, nsDerivedKeyLength)
if result != 0 {
let errorDescription = "CCKeyDerivationPBKDF failed with error: '\(result)'"
// error.memory = MyError(domain: ClientErrorType.errorDomain, code: Int(result), descriptionText: errorDescription)
return nil
}
return (nsDerivedKey, actualRoundCount)
}
//增加了奖励：
func salt(#length:UInt) -> NSData { let salt = NSMutableData(length: Int(length))
var saltPointer = UnsafeMutablePointer<UInt8>(salt.mutableBytes)
SecRandomCopyBytes(kSecRandomDefault, length, saltPointer);
return salt
}
//测试电话：
let password = "test pass"let salt = self.salt(length:32)
let roundCount = 300
var error: NSError?
let result = self.generateAesKeyForPassword(password, salt:salt, roundCount:roundCount, error:&error)
println("result: \(result)")
输出：
result: Optional((<d279ab8d 8ace67b7 abec844c b9979d20 f2bb0a7f 5af70502 085bf1e4 1016b20c>, 300))以上是 Swift：如何从Swift调用CCKeyDerivationPBKDF 的全部内容， 来源链接： utcz.com/qa/403781.html
