Do I really suspect that this generated PHP code is vulnerable?

Question

I am not very educated in PHP or Web security in general, but I strongly suspect that the code created by some software for which I work is unsafe.

Here are some snippets of what bothers me:

First problem:

$sql = "SELECT password, fullname FROM ".$mysql_table." 
WHERE username = '".mysqli_real_escape_string($db,$_POST['username'])."'";

Is it wrong to get a password for a given username and then compare them in PHP, or is it better to use a password in the request itself, for example:

... WHERE username = $username AND password = $hashed_password

The second problem:

$crypt_pass = md5($_POST['password']);
if ($crypt_pass == $data['password'])
{
    //LOGIN SUCCESS
}

Uses md5 hashing and doesn't use salt, is that enough?

Third question:

 setcookie('username', $_POST['username'], time() + 3600*24*30);
 setcookie('password', $_POST['password'], time() + 3600*24*30);

Is it good to store plain / text usernames and passwords in a cookie?

Is any of this code unsafe, and if so, what should be done instead?

Answer 1

:

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"0e111111" == "0e123456"; # true, in PHP world.

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. , , , . . MD5 , . , 482c811da5d5b4bc6d497ffa98491e38 , , "password123".

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Answer 2

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MD5, @gabe3886, . : http://www.openwall.com/phpass/. . .

, . .: fooobar.com/questions/98332/...

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