c# - ASP.NET MVC LinQ - Use our own method in "Any" LinQ expression? -

i'm coding login page in asp.net mvc multiple articles found on web have problem find matching user in database. here post method :

    [httppost]     [validateantiforgerytoken]     public actionresult login([bind(include = "username, password")] user model, string returnurl)     {         if (modelstate.isvalid)         {             string username = model.username.tolower();             string plainpassword = model.password;              bool uservalid = db.user.any(u => sha512.verifyhash(plainpassword, u.salt, u.password) && u.username_canonical == username);              if (uservalid)             {                 formsauthentication.setauthcookie(username, false);                  if (url.islocalurl(returnurl) && returnurl.length > 1 && returnurl.startswith("/") && !returnurl.startswith("//") && !returnurl.startswith("/\\"))                 {                     return redirect(returnurl);                 }                 else                 {                     return redirecttoaction("index", "home");                 }             }             else             {                 modelstate.addmodelerror("", "the username or password provided incorrect.");             }         }          // if got far, failed, redisplay form         return view(model);     } 

i got "notsupportedexception" in line :

bool uservalid = db.user.any(u => sha512.verifyhash(plainpassword, u.salt, u.password) && u.username_canonical == username); 

linq entities not recognize method 'boolean verifyhash(system.string, system.string, system.string)' method, , method cannot translated store expression.

here in mind : verifyhash returns true if provided password (uncrypted) matches crypted 1 stored in database (by getting salt corresponding username, in database , re-encrypting provided password salt, compare newly encrypted hash stored one). usernames uniques.

i understand doesn't accept verifyhash method inside "any" one. don't know how else because need corresponding salt , encrypted password (u.salt , u.password) in addition matching username verify password.

i tried use "find" method in same way doesn't work (vs error, memory need user id pass parameter). i'm new linq entities.

any idea ? forgive eventual english mistakes.

thanks,

hellcat

you getting exception, because entity framework cannot translate method verifyhash sql syntax. verifyhash implemented in c# , not have corresponding method in sql.

why don't first search user username , verify password. can this:

var userfromdb = db.user.firstordefault(u => u.username_canonical == username); if(userfromdb !=null) {     var uservalid = sha512.verifyhash(plainpassword, userfromdb.salt, userfromdb.password)     if (uservalid)     {         // logic     } }