How to implement Security Protocols TLS 1.2 in .Net 3.5 framework

Question

As Paypal updated their response, I need to update security protocols TLS to v1.2 in my existing application which is on .NET 3.5 framework. What changes required to update this in existing code, I cannot update the application to newer framework.

D_Bester · Answer 1 · 2019-02-25T17:31:00.560

24

I'm using VS 2008 with .net 3.5.30729.4926. All I had to do was:

Add imports:

Imports System.Security.Authentication
Imports System.Net

Add this to my code (C#):

public const SslProtocols _Tls12 = (SslProtocols)0x00000C00;
public const SecurityProtocolType Tls12 = (SecurityProtocolType)_Tls12;
ServicePointManager.SecurityProtocol = Tls12;

VB.net version:

Const _Tls12 As SslProtocols = DirectCast(&HC00, SslProtocols)
Const Tls12 As SecurityProtocolType = DirectCast(_Tls12, SecurityProtocolType)
ServicePointManager.SecurityProtocol = Tls12

Dim wbrq As HttpWebRequest
Dim wbrs As HttpWebResponse
Dim sw As StreamWriter
Dim sr As StreamReader
Dim strResult As String

'Create a new HttpWebRequest object.
wbrq = WebRequest.Create(strURL)
wbrq.Method = "POST"
wbrq.ContentLength = DataString.Length
wbrq.ContentType = "application/x-www-form-urlencoded"

'upload data
sw = New StreamWriter(wbrq.GetRequestStream)
sw.Write(DataString)
sw.Close()

'get response
wbrs = wbrq.GetResponse
sr = New StreamReader(wbrs.GetResponseStream)
strResult = sr.ReadToEnd.Trim
sr.Close()

edited Feb 25 '19 at 17:31

answered Jul 03 '17 at 20:06

D_Bester

5,723
5
35
77

1

@Cullub Thanks. I suspect MS might retrofit the constant in older versions of .net. – D_Bester Aug 04 '17 at 15:50
This is better than the other answer at the moment - it doesn't depend on a broken link ;-) – Cullub Aug 04 '17 at 15:52
Where in the code was this placed? In a class? or global.asax? etc? – Anna Aug 14 '17 at 20:57
1

@Anna The SecurityProtocol is set immediately before making a HttpWebRequest. See my edited post above. – D_Bester Aug 16 '17 at 13:24
Just to confirm, did you have to apply any hotfix and edit the registry to enable TLS 1.2 on the server? Or is it just using the code mentioned above? – Anna Aug 17 '17 at 14:15
1

@Anna No hotfixes or registry edits. Just the code above. YMMV – D_Bester Aug 17 '17 at 14:26
Just `ServicePointManager.SecurityProtocol = (SecurityProtocolType)0x00000C00;` for a C# project was sufficient for me. – Kenny Evitt Apr 17 '18 at 14:19
You code save me :d. Thank you very much. Net 2.0 can use this code. – Nguyên Ngô Duy May 29 '19 at 07:23

score 3 · Answer 2 · answered Apr 10 '18 at 07:33

just adding adding Your code in vb .net 3.5 version :

ServicePointManager.SecurityProtocol = DirectCast(3072, SecurityProtocolType)

then Your code become :

ServicePointManager.SecurityProtocol = DirectCast(3072, SecurityProtocolType)

Dim wbrq As HttpWebRequest
Dim wbrs As HttpWebResponse
Dim sw As StreamWriter
Dim sr As StreamReader
Dim strResult As String

'Create a new HttpWebRequest object.
wbrq = WebRequest.Create(strURL)
wbrq.Method = "POST"
wbrq.ContentLength = DataString.Length
wbrq.ContentType = "application/x-www-form-urlencoded"
.............

hope this help

score 2 · Answer 3 · answered Mar 08 '17 at 10:37

2

If you are on NET 3.5.1 you have an option of applying a rollup hotfix and apply a registry edit to tell .NET to use the system default. More details here

Failing that you need to be using .NET 4.5 for TLS 1.2 & 1.1 support and on Windows Server 2008 R2 at a minimum.

answered Mar 08 '17 at 10:37

Ian Bennett

360
3
10

Your link is broken. – Cullub Aug 04 '17 at 15:43

score 0 · Answer 4 · answered Aug 28 '23 at 14:09

0

Add de following code:

System.Net.ServicePointManager.SecurityProtocol |= SecurityProtocolType.Tls12 | SecurityProtocolType.Tls11 | SecurityProtocolType.Tls;

More details here

answered Aug 28 '23 at 14:09

Jorge

1

How to implement Security Protocols TLS 1.2 in .Net 3.5 framework

4 Answers4

Linked