Download web pages via HTTPS - weak DH 768bit on Windows C#
$750-1500 USD
Chiuso
Pubblicato quasi 8 anni fa
$750-1500 USD
Pagato al completamento
We need code in VB.NET 4.5.2 to download web pages via HTTPS from web servers which have weak and strong ciphers/Diffie-Hellman key exchanges.
Sounds super easy but difficulty is that Microsoft has rolled out recenlty updates which now block weak (512/768) Diffie Hellman Key Exchanges. We download pages via HTTPs from multiple servers which we have no access and which have WEAK (DH 768 bit) and strong ciphers. Microsoft now blocks weak ciphers by default and the following registry key enables HTTPS on weak DH 768 bit:
[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\SecurityProviders\SCHANNEL\KeyExchangeAlgorithms\Diffie-Hellman]
"ClientMinKeyBitLength"=dword:00000200 (512bit)
We need a code solution which works for all ciphers with the latest Microsoft updates. The registry can NOT be changed so above key can registry NOT be set (although this would make it work).
Roughly the code looks as follows (to illustrate the requirements).
1.) Allow weak DH (768bit) via Microsoft CSP provider (this is the MAGIC required here)
2.) Download page via HTTTPs (Trivial), as follows:
[login to view URL] = Function() True
[login to view URL] = False 'was false MK Fix 1July2017
[login to view URL] = [login to view URL] Or [login to view URL]
Dim req As HttpWebRequest = DirectCast([login to view URL](url), HttpWebRequest)
3.) Undo any permanent changes done in 1.)
The solution should not require admin privileges, THe registry can NOT be changed.
Do not attempt this solution if you are not an expert in SSH, diffie Hellman, encryption or Microsoft CSP. You will also likely need Pinvoke to use C++ style calls to crypto libs on WIndows.
Acceptance criteria: Fully working code which works to download the web page via any HTTPS and cipher combination. We will test but not fix your code. Escrow will be only released in full when the code fully works. No partial $ will be paid for hours spend with partial results.
When submitting the solution, you must include how you have tested your code towards public testing servers with HTTPS and weak 512/768 Diffie Hellman and also strong ciphers.
Deliverables: Windows FOrm Application which has a text box to enter URL to download page. Button to download which then Msgbox(pagecontent). Visual Studio 2015 code in .NET 4.5.2 in Visual Basic. YOu can of course start in C# and then convert to vb.net.
Hello
I'm interesting your project very well
I'm a Good C#, HTTPS, Encryption, Math, Algorithm expert.
I m quite well experienced in these jobs.
Let's go ahead with me
I want to service for you continously.
Thanks
Hi
I have been in this industry for 5 years and such jobs are my daily practice.I can assure you that if you work with me once, you will always work with me for these kind of projects.
Hello,
I understood the initial scope of this project.
Although i want to discuss further this job in order to
prepare the final concept for this project.
After Complete discussion over the call or in chat, i
will prepare following things for you
- Technical Project Proposal
- Flow chart for this Project
- Execution plan (Step by step procedure with explanation how and at what that we are going to execute a particular task)
My name is Mike and I’m from UK. I work with individual clients and also provide outsourcing services for a number of UK and USA based agencies. Your project description sounds interesting to me and I do have skills & experience that are required to complete this project. I can show you some examples of my work. Please contact me to discuss your project.
Dear Client, Greetings from Flowgica technologies,
I have experience with these skills. We do have similar experience doing something similar to yours therefore I am looking forward to discuss and move ahead.
please check our freelancer portfolio at https://www.freelancer.com/u/mmadi.html?page=portfolio
I am ready to work with you,kindly waiting for your response.
Thanks & Regards,
Mmadi