Do not use a predictable salt

Metadata

ID: csharp-security/no-predictable-salt

Language: C#

Severity: Error

Category: Security

Description

A salt to hash a password should always be different for each user. Otherwise, it becomes an attack vector. As mentioned on Wikipedia “The way salting is typically done is that a new salt is randomly generated for each password”.

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Non-Compliant Code Examples

using System.Security.Cryptography;

class MyClass {
    public static void createHashedPassword1(password)
    {
        var salt = Encoding.UTF8.GetBytes("myuniquesalt");
        return new Rfc2898DeriveBytes(password, salt);
    }

    public static void createHashedPassword2(password)
    {
        return new Rfc2898DeriveBytes(password, Encoding.UTF8.GetBytes("myuniquesalt"));
    }

    public static void createHashedPassword3(password)
    {
        return new Rfc2898DeriveBytes(password, GetBytes("myuniquesalt"));
    }
}

Compliant Code Examples

using System.Security.Cryptography;

class MyClass {
    public static void createHashedPassword(password)
    {
        return new Rfc2898DeriveBytes(password, 32);
    }
}