Edit

SYSLIB0033: Rfc2898DeriveBytes.CryptDeriveKey is obsolete

  • Article

The Rfc2898DeriveBytes.CryptDeriveKey(String, String, Int32, Byte[]) method is marked as obsolete, starting in .NET 6. Using this API in code generates warning SYSLIB0033 at compile time.

Workaround

Use PasswordDeriveBytes.CryptDeriveKey(String, String, Int32, Byte[]) instead.

Suppress a warning

If you must use the obsolete APIs, you can suppress the warning in code or in your project file.

To suppress only a single violation, add preprocessor directives to your source file to disable and then re-enable the warning.

// Disable the warning.
#pragma warning disable SYSLIB0033

// Code that uses obsolete API.
// ...

// Re-enable the warning.
#pragma warning restore SYSLIB0033

To suppress all the SYSLIB0033 warnings in your project, add a <NoWarn> property to your project file.

<Project Sdk="Microsoft.NET.Sdk">
  <PropertyGroup>
   ...
   <NoWarn>$(NoWarn);SYSLIB0033</NoWarn>
  </PropertyGroup>
</Project>

For more information, see Suppress warnings.