CA5364: Do not use deprecated security protocols
Property | Value |
---|---|
Rule ID | CA5364 |
Title | Do not use deprecated security protocols |
Category | Security |
Fix is breaking or non-breaking | Non-breaking |
Enabled by default in .NET 9 | No |
Cause
This rule fires when either of the following conditions are met:
- A deprecated System.Net.SecurityProtocolType value was referenced.
- An integer value representing a deprecated value was assigned to a SecurityProtocolType variable.
Deprecated values are:
- Ssl3
- Tls
- Tls10
- Tls11
Rule description
Transport Layer Security (TLS) secures communication between computers, most commonly with Hypertext Transfer Protocol Secure (HTTPS). Older protocol versions of TLS are less secure than TLS 1.2 and TLS 1.3 and are more likely to have new vulnerabilities. Avoid older protocol versions to minimize risk. For guidance on identifying and removing deprecated protocol versions, see Solving the TLS 1.0 Problem, 2nd Edition.
How to fix violations
Don't use deprecated TLS protocol versions.
When to suppress warnings
You can suppress this warning if:
- The reference to the deprecated protocol version isn't being used to enable a deprecated version.
- You need to connect to a legacy service that can't be upgraded to use secure TLS configurations.
Suppress a warning
If you just want to suppress a single violation, add preprocessor directives to your source file to disable and then re-enable the rule.
#pragma warning disable CA5364
// The code that's violating the rule is on this line.
#pragma warning restore CA5364
To disable the rule for a file, folder, or project, set its severity to none
in the configuration file.
[*.{cs,vb}]
dotnet_diagnostic.CA5364.severity = none
For more information, see How to suppress code analysis warnings.
Pseudo-code examples
Enumeration name violation
using System;
using System.Net;
public class ExampleClass
{
public void ExampleMethod()
{
// CA5364 violation
ServicePointManager.SecurityProtocol = SecurityProtocolType.Tls11 | SecurityProtocolType.Tls12;
}
}
Imports System
Imports System.Net
Public Class TestClass
Public Sub ExampleMethod()
' CA5364 violation
ServicePointManager.SecurityProtocol = SecurityProtocolType.Tls11 Or SecurityProtocolType.Tls12
End Sub
End Class
Integer value violation
using System;
using System.Net;
public class ExampleClass
{
public void ExampleMethod()
{
// CA5364 violation
ServicePointManager.SecurityProtocol = (SecurityProtocolType) 768; // TLS 1.1
}
}
Imports System
Imports System.Net
Public Class TestClass
Public Sub ExampleMethod()
' CA5364 violation
ServicePointManager.SecurityProtocol = CType(768, SecurityProtocolType) ' TLS 1.1
End Sub
End Class
Solution
using System;
using System.Net;
public class TestClass
{
public void TestMethod()
{
// Let the operating system decide what TLS protocol version to use.
// See https://learn.microsoft.com/dotnet/framework/network-programming/tls
}
}
Imports System
Imports System.Net
Public Class TestClass
Public Sub ExampleMethod()
' Let the operating system decide what TLS protocol version to use.
' See https://learn.microsoft.com/dotnet/framework/network-programming/tls
End Sub
End Class
Related rules
CA5386: Avoid hardcoding SecurityProtocolType value