Getting all kinds of crypted string from the original string (keep updating...)

String+Crypto.swift

// You should put "#import <CommonCrypto/CommonHMAC.h>" in the bridge header before using these code

import Foundation

extension String {
    func sha256() -> String {
        if let stringData = self.data(using: String.Encoding.utf8) as NSData? {
            let digest = digestSHA256(source: stringData)
            var bytes = [UInt8](repeating: 0, count: digest.length)
            digest.getBytes(&bytes, length: digest.length)
            var hexString = ""
            for byte in bytes {
                hexString += String(format: "%02x", UInt8(byte))
            }
            return hexString
        } else {
            return ""
        }
    }
    
    private func digestSHA256(source: NSData) -> NSData {
        let length = Int(CC_SHA256_DIGEST_LENGTH)
        var hash = [UInt8](repeating: 0, count: length)
        CC_SHA256(source.bytes, UInt32(source.length), &hash)
        return NSData(bytes: hash, length: length)
    }
}