text Metaobjects污染和无污染

Posted 2021-05-02

package metaobjectTest

import untainted


object Tainted

    func run {
        var String@tainted(sql) maliciousSqlCode = 
           "I will delete your database";
        
        var String@untainted(sql) safeSqlCode;
        

          // compile-time error: this assignment should
          // be in a special prototype/package to be allowed
        // safeSqlCode = "safe sql code";
            // ok
        safeSqlCode = TaintedToUntainted toUntaintedSql: "safe sql code";
         
        // TaintedToUntainted is a safe prototype
        safeSqlCode = TaintedToUntainted toUntaintedSql: "safe sql code";
        
        maliciousSqlCode = safeSqlCode; // ok
        //safeSqlCode = maliciousSqlCode; // compile-time error
        
        let String@tainted(html) badHtmlCode = "bad home page";
           // compile-time error
        //safeSqlCode = badHtmlCode;

           // compile-time error
        //let String@untainted(html) safeHtmlCode = badHtmlCode;
        
    }
    
end