我正试图从Swift调用CCKeyDerivationPBKDF.
我在Project-Bridging-Header.h中导入了所需的标题：
#import <CommonCrypto/CommonKeyDerivation.h>
(顺便说一下,桥接头似乎可以正常导入我项目中的其他Objective C代码).
在Xcode中,我可以从我的.swift文件跳转到这里显示的定义：
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)
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：
Cannot invoke ‘init’ with an argument list of type ‘(CCPBKDFAlgorithm,
UnsafePointer,size_t,UnsafePointer,
CCPseudoRandomAlgorithm,uint,UnsafeMutablePointer,size_t)’
我相信所有演员阵容都是正确的(实际上编译器错误帮助我识别每个参数的每个问题) – 这让我觉得编译器理解我调用CCKeyDerivationPBKDF的意图.
然而,在所有其他转换错误消失后,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.
希望有人能告诉我我的方式的错误.
(Xcode 6 beta 7)
根据要求,上下文中的完整代码：
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),UInt(derivedKey.length),UInt32(300) /* milliseconds */));
}
let result = CCKeyDerivationPBKDF(CCPBKDFAlgorithm(kCCPBKDF2),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)
}
斯威夫特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,rounds: Int) -> Data? {
return pbkdf2(hash:CCPBKDFAlgorithm(kCCPRFHmacAlgSHA256),rounds:rounds)
}
func pbkdf2SHA512(password: String,rounds: Int) -> Data? {
return pbkdf2(hash:CCPBKDFAlgorithm(kCCPRFHmacAlgSHA512),rounds:rounds)
}
func pbkdf2(hash :CCPBKDFAlgorithm,password: String,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])
let keyByteCount = 16
let rounds = 100000
let derivedKey = pbkdf2SHA1(password:password,rounds:rounds)
print("derivedKey (SHA1): \(derivedKey! as NSData)")
示例输出：
derivedKey (SHA1): <6b9d4fa3 0385d128 f6d196ee 3f1d6dbf>
Swift 2.x：
参数类型和类的微小更改以及测试的实例方法.
func generateAesKeyForPassword(password: String,roundCount: Int?,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,actualRoundCount,nsDerivedKeyPointer,nsDerivedKeyLength)
if result != 0 {
let errorDescription = "CCKeyDerivationPBKDF Failed with error: '\(result)'"
// error.memory = MyError(domain: ClientErrorType.errorDomain,descriptionText: errorDescription)
return nil
}
return (nsDerivedKey,actualRoundCount)
}
//添加奖金：
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,roundCount:roundCount,error:&error)
println("result: \(result)")
输出：
result: Optional((<d279ab8d 8ace67b7 abec844c b9979d20 f2bb0a7f 5af70502 085bf1e4 1016b20c>,300))
