Two Dimension Array of size 10 - arrays

starting with programming and would like tips on writing pseudocode for a 2 Dimension array in a main class that stores usernames and passwords for each account.
Program should take a username input, store it in the array - preferbly using a function(Function that adds usernames and passwords or different functions adding each seperately), and then a password store it in a correspoding dimension to the user name enter - for an array sizeof 10: ArraySize(10)(10) all
Should be able to login(Account Search Function - could search both password and function using the same function or two function searching each part separetly) to the account with check of password combination(Function that checks password limit = 3)
Should be able to delete. So login first, and then delete an invidual account.

Related

How to store all Azure AD user group members in an array using a logic app

I am working on a logic app that will create users in third party applications based on AAD group membership. To avoid issues when the group has more than 999 users I have implemented paging. I first get the first 50 users, and a NextLink that I call to get the next 50. This loop runs fine.
Snippet of logic app
When no more nextlink is found, the loop exits. During the loop iterations, I need to store the user information (first name, lastname, UPN etc) in an array so i can process everyone after running through the loop. I have tried running the Union expression as follows:
union(variables('AllUserInfoArray'),body('HTTP_-_Request_My_Group_Name_group_members')['value'])
But this does not add the user data to the AllUserInfoArray, it creates a new array (Compose->Outputs). How do I add all userdata into the AllUserInfoArray array so I can loop through all users once all user info has been gathered?
According to the description of your problem, your concern is the "union" in "Compose" action creates a new array which contains both of the collections(array) but why not append the array from http request to the array "AllUserInfoArray". But why not create an action after the "Compose" to set the variable "AllUserInfoArray" with output value of the "Compose". And then we can do the union again to modify "AllUserInfoArray" in the next loop.

Are there known issues with the C function crypt()?

I use crypt() to encrypt passwords for a project of mine. When the password is chosen by the user, it's encrypted like this:
password = crypt(<password chosen>, <user's account name>)
The problem is when the user logs in using their password. If what they type doesn't match their password, it should enter this if check:
if (strcmp(crypt(<what user types in as password>, <user's account name>), <user's encrypted password>)) {
//...
}
It doesn't in one certain scenario. Let's say their password is 'asdf'. If they enter 'asdf' with any random trailing characters, such as 'asdffffff' or 'asdf339sfd', it still accepts the password. It seems to ignore everything after 'asdf'.
Is this a known issue with crypt? Is there another way to encrypt passwords?
The second argument to crypt is not supposed to be the user's account name. It's supposed to be a setting string. Setting strings look like this:
$2b$07$fQuDK3TaQP4sw6IX6iVcTw
The $2b$07$ part tells crypt which password-hashing algorithm to use, and the string of random characters that follows is the salt. The salt must be different for each user, but it is not supposed to have any correlation with the user's account name. It doesn't technically have to be random, but it's critical that it be different for each user, and it needs to change every time the user changes their password, so best practice is to use a long string drawn from a cryptographic PRNG.
When you authenticate a user who has logged in before, you use the stored hashed password as the setting string:
char *new_hash = crypt("password typed in", "stored hash");
if (new_hash && !strcmp(new_hash, "stored hash")) {
// user has successfully logged in
}
This works because the stored hashed password always begins with the setting string that was used to create it in the first place, and crypt is coded to look only at the setting-string part.
(Also note the null check; some implementations of crypt can fail and report failure by returning a null pointer.)
When you create a new account or change a password, you have to generate a new setting string. If you have the function crypt_gensalt, use that:
char *new_setting = crypt_gensalt("$2b$", 0, 0, 0);
if (new_setting) {
char *new_hash = crypt("user's new password", new_setting);
// ...
} else {
// halt and catch fire
}
If you don't have crypt_gensalt you have to implement it yourself, unfortunately. (To make matters worse, some Unixes have the crypt_gensalt whose documentation I linked to above, and others have a different version, with the same name, doing the same job, but taking different arguments. Time to dust off your Autoconf skillz!)
Now you know all of that, I can explain why
password = crypt("password chosen", "user's account name");
appeared to work but truncated the password. Your user account names probably begin with at least two alphanumeric characters, right? Like, "Ma[ya]", or "zw[ol]"? Unfortunately, any two alphanumeric characters make a valid setting string ... that selects one of the oldest and least secure password-hashing algorithms known to science, descrypt. (It was pretty good when it was invented ... in the mid-1970s. Nowadays, it can be cracked by brute force no matter what the password is.) One of the many problems with this algorithm is that it truncates all passwords to eight characters. asdf and asdfhjkl hash to different things, but asdfhjkl and asdfhjkl1234 hash to the same thing.
The cure for this is to use crypt_gensalt or equivalent to select a modern algorithm. All the modern algorithms accept arbitrarily long passphrases.

How to save variables on access storage without a table?

I've protected delete queries on my forms with a password (did it with some VBA) and I let the user change the password so I can't just compare it to a text when I ask the user to enter the password, is there any way I could save the password variable on access storage without a table?
currently, I'm saving the password on a table with one field and doing the comparisons at the background...
It's a school project.
I would suggest hashing the password and storing the hash in your table; then, when the user enters a password, hash the entered password and compare the result with the stored hash.
This approach has the benefit that no passwords are stored in human readable format, and the hashing process cannot be reversed to yield the plain text password from the stored hash (one could only brute-force guess the password and compare the resulting hash).
You can save the password, but better password hash as advised #Lee Mac in the database properties. Property can be changed at any time by code. Change remains in the database file after database closing.
Create property:
Function CreatePropery()
Dim DB As Database
Dim P As Property
Set DB = CurrentDb
Set P = DB.CreateProperty("MyPassword", DB_TEXT, "MyInitialPassword")
DB.Properties.Append P
End Function
Get current password:
Function GetPasswod()
GetPasswod = CurrentDb.Properties![MyPassword]
End Function
Set new password:
Function SetPassword(strNewPassword As String)
CurrentDb.Properties![MyPassword] = strNewPassword
End Function

How to use the validation method?

Hi i made a portal for institute and now need to use validation method so username cannot be repeated at the time of registration. So how to use array list in validate method.
You need to check all records of table if you use array list for check repeated username instead of this use
"select * from table_name where username='pass the string that user enter for user name'"
You can get only one row if that user name exist so it will reduce your code.
If it's not repeated then returning row will be zero so you can easily check this by simple if and else condition.

What's the safest encryption I can use for a user to login to my program?

I'm writing a program and before it loads I want the user to enter the correct password without storing the password anywhere in my code. I've implemented MD5 hashes before but from what I've read they're outdated and can be broken. There are a few sites out there that attempt to reverse engineer and MD5 hash. What's the strongest encryption I can use to keep prying eyes out of my program (e.g., The NSA)?
"Encryption" is not the right thing to do for storing user passwords - as by design an encrypted password can be decrypted. As you said - hashing is the way to go.
MD5 is outdated, and I believe the current recommendation is sha1.
Note that there are ways to reverse any hashing algorithm to acceptable input. The commonly accepted standard to make this much more dificult is to add a unique "salt" to all passwords before putting them through the hashing function. A common mistake made when adding salts to passwords is to use the same salt value on every password in the database.
When salting passwords, use a unique value, for example the user ID, or the created date/time string for the user record. This will prevent attacks based on rainbow tables because there will be no existing ready to use rainbow table for your stored password hashes.
I personally like the approach of using the created date / time string of the user as it's a value that should never change and will be available and will likely be different for each user the the database.
Eexamples below assume you are familiar with PHP - however the concepts can be applied to any language.
Example:
Before saving a new user into the database:
$date = date('Y-m-d H:i:s');
// save this same value into the user record somewhere
$passwordHash = sha1($user['created_date'].$_POST['password']);
// and save the $passwordHash value into the password field for that user
To authenticate a login attempt, use something like the following:
function authenticateUserLogin($email, $password) {
$user = $db->fetchRow('SELECT * FROM users WHERE email=?', array($email));
if (!$user) return false;
$passwordHash = sha1($user['created_date'].$password);
return $user['password_hash'] !== $passwordHash;
}
To update an existing users password, use something like...
$passwordHash = sha1($user['date_created'].$newPassword);
$db->query('UPDATE users set password_hash=? WHERE id = ?', array($passwordHash, $user['id']));

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