swift 3.0 哈希sha1方法

#import <CommonCrypto/CommonCrypto.h>//sha1func sha1() -> String{    let data = self.data(using: String.Encoding.utf8, allowLossyConversion: true)!    let uint8Ptr = UnsafeMutablePointer<UInt8>.allocate(capacity: data.count)    uint8Ptr.initialize(from: data) //<-copying the data    let rawPtr = UnsafeRawPointer(uint8Ptr)    var digest = [UInt8](repeating:0,count:Int(CC_SHA1_DIGEST_LENGTH))    CC_SHA1(rawPtr, CC_LONG(data.count), &digest)    let output = NSMutableString(capacity: Int(CC_SHA1_DIGEST_LENGTH))    for byte in digest{        output.appendFormat("%02x", byte)    }    return output as String}