SYSLIB0023: RNGCryptoServiceProvider is obsolete

RNGCryptoServiceProvider is marked as obsolete, starting in .NET 6. Using it in code generates warning SYSLIB0023 at compile time.


To generate a random number, use one of the RandomNumberGenerator methods instead, for example, RandomNumberGenerator.GetInt32(Int32).

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 SYSLIB0023

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

// Re-enable the warning.
#pragma warning restore SYSLIB0023

To suppress all the SYSLIB0023 warnings in your project, add a <NoWarn> property to your project file.

<Project Sdk="Microsoft.NET.Sdk">

For more information, see Suppress warnings.