How to verify accounts (logins)?

spode

I have two field. in the first one the user writes his own data (user or password) and in the second one he writes his password. How verify these login data?

tobias.hunger

That depends on how you want to authenticate the user. Is this a application specific login dialog, some database, the OS, a service on the network, etc.?

ninio

Well, there is some ways to do it. You can check the fields against a data base.

absfrm

if you have any database or data files , you can authenticate the user very easy.
For Example :
use can use sqlite db with hash password.

DerManu

[quote author="abbas farahmand" date="1342495126"]
use can use sqlite db with hash password.[/quote]

With salted hashed password.
http://en.wikipedia.org/wiki/Cryptographic_salt

Further, don't use a fast hash function like MD5 or SHA. Use a scheme that you can make slower as computing power grows, without breaking your code. See for example
http://en.wikipedia.org/wiki/Bcrypt

If the authentication happens over the network, use a nonce (and SSL).
http://en.wikipedia.org/wiki/Cryptographic_nonce

If you think this is too much work, don't write the program. Don't implement your security/authentication layer as dilettantish as sony, last.fm, eHarmony, linkedin etc. did – You've read in the news what happens.