Host unreachable in https due to weak Http2 cipher

[tebeco]

Describe the bug

The browser is not happy with the cipher used for HTTP2 (i guess)
ERR_SPDY_INADEQUATE_TRANSPORT_SECURITY and equivalent in chrome

Bad Workaround

only for firefox
i managed to go in about:config and disable weak cypher check this actually has an effect

is there a simple way to completely disable HTTP2 via a Kestrel IOptions<> ?

To Reproduce

Steps to reproduce the behavior:

1. uninstalled ALL sdk
2. removed folder from program files/user/appdata/temp
3. install sdk 2.2.105 and 3.0.0-preview3 from https://dot.net
4. version of ASP.NET Core : the one shipped with preview3
5. dotnet new webapi -n foo
6. comment out UseHsts
7. comment out UseHttpsRedirection()
8. dotnet run --project foo.csproj
9. hit the http endpoint => works
10. hit the https endpoint => rejected

Expected behavior

i tried to :

• dotnet dev-certs http --clean
• dotnet dev-certs http --trust
• delete .vs/
• change launchSettings.json to anything else
• removed UseHttpsRedirection()
• removed UseHsts()
• not working for IP / dns in the browser

pretty sure all i did was update Vs2019, it was workign 2 weeks ago on the same SDK (or the latest win10 insider - fast ring update)

>dotnet --version
3.0.100-preview3-010431

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

  <PropertyGroup>
    <TargetFramework>netcoreapp3.0</TargetFramework>
  </PropertyGroup>

  <ItemGroup>
    <PackageReference Include="Microsoft.AspNetCore.Mvc.NewtonsoftJson" Version="3.0.0-preview3-19153-02" />
  </ItemGroup>

</Project>

[Tratcher]

What OS is the server on? We've seen this on 2012/Win8.

You can opt out of HTTP/2 using these options:
https://docs.microsoft.com/en-us/aspnet/core/fundamentals/servers/kestrel?view=aspnetcore-2.2#listenoptionsprotocols
E.g.:

{
  "Kestrel": {
    "EndPointDefaults": {
      "Protocols": "Http1"
    }
  }
}

See platform requirements here:
https://docs.microsoft.com/en-us/aspnet/core/fundamentals/servers/kestrel?view=aspnetcore-2.2#http2-support

[tebeco]

Windows 10 - Fast ring insider
Vs2019 preview
netcoreapp3.0.0 preview
(bunch of edge stuff ^^)

was working fine last week. Was hit by an insider bump + latest preview of vs2019 since

also tried to add 2 registry key to disable HTTP2 for Win2016 server.
it had no effect on any browser

[Tratcher]

Those reg keys are only for IIS/Http.Sys. I wonder if Insiders has a regression. @shirhatti

[tebeco]

Is it a way to let developper knows that they are running on a server that may end up like this ?

For example a dotnet tool listing cipher that can be used on the current machine / server with, for example colors to indicate potential weak cipher and so on.
Or a boolean to make the server agressive and failfast if the cipher listed are too weak at startup time.

This would required to know the list of the "acceptable" one and i truly have no idea if such a list exist and if it's possible at all

took me a long time to realize where it was coming from

[Tratcher]

Can you give the specific windows build number?

We'd only add this kind of tooling if we could no longer say it worked on all rtm win10 builds.

[shirhatti]

As of the 1803 update, IIS allows you to control Http.Sys on a per binding basis. You no longer need to disable HTTP/2 for the entire server.

That being said, the global reg key should still work. Can you share your Windows build number and I'll look into it

[Tratcher]

@shirhatti they're using Kestrel.

[shirhatti]

Whoops 🤦‍♂️. Ignore my previous comment.

[tebeco]

also i really don't want to disable Http2 if it can be fixed ;)

[tebeco]

@Tratcher
does this helps ?

> systeminfo
OS Version:                10.0.18362 N/A Build 18362
OS Configuration:          Standalone Workstation

> Get-TlsCipherSuite


KeyType               : 0
Certificate           :
MaximumExchangeLength : 0
MinimumExchangeLength : 0
Exchange              :
HashLength            : 0
Hash                  :
CipherBlockLength     : 16
CipherLength          : 256
BaseCipherSuite       : 4866
CipherSuite           : 4866
Cipher                : AES
Name                  : TLS_AES_256_GCM_SHA384
Protocols             : {772}

KeyType               : 0
Certificate           :
MaximumExchangeLength : 0
MinimumExchangeLength : 0
Exchange              :
HashLength            : 0
Hash                  :
CipherBlockLength     : 16
CipherLength          : 128
BaseCipherSuite       : 4865
CipherSuite           : 4865
Cipher                : AES
Name                  : TLS_AES_128_GCM_SHA256
Protocols             : {772}

KeyType               : 0
Certificate           :
MaximumExchangeLength : 0
MinimumExchangeLength : 0
Exchange              :
HashLength            : 0
Hash                  :
CipherBlockLength     : 0
CipherLength          : 0
BaseCipherSuite       : 0
CipherSuite           : 0
Cipher                :
Name                  : TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384
Protocols             : {}

KeyType               : 0
Certificate           : ECDSA
MaximumExchangeLength : 65536
MinimumExchangeLength : 0
Exchange              : ECDH
HashLength            : 0
Hash                  :
CipherBlockLength     : 16
CipherLength          : 128
BaseCipherSuite       : 49195
CipherSuite           : 49195
Cipher                : AES
Name                  : TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256
Protocols             : {771, 65277}

KeyType               : 0
Certificate           : RSA
MaximumExchangeLength : 65536
MinimumExchangeLength : 0
Exchange              : ECDH
HashLength            : 0
Hash                  :
CipherBlockLength     : 16
CipherLength          : 256
BaseCipherSuite       : 49200
CipherSuite           : 49200
Cipher                : AES
Name                  : TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384
Protocols             : {771, 65277}

KeyType               : 0
Certificate           : RSA
MaximumExchangeLength : 65536
MinimumExchangeLength : 0
Exchange              : ECDH
HashLength            : 0
Hash                  :
CipherBlockLength     : 16
CipherLength          : 128
BaseCipherSuite       : 49199
CipherSuite           : 49199
Cipher                : AES
Name                  : TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256
Protocols             : {771, 65277}

KeyType               : 0
Certificate           : RSA
MaximumExchangeLength : 1024
MinimumExchangeLength : 1024
Exchange              : DH
HashLength            : 0
Hash                  :
CipherBlockLength     : 16
CipherLength          : 256
BaseCipherSuite       : 159
CipherSuite           : 159
Cipher                : AES
Name                  : TLS_DHE_RSA_WITH_AES_256_GCM_SHA384
Protocols             : {771, 65277}

KeyType               : 0
Certificate           : RSA
MaximumExchangeLength : 1024
MinimumExchangeLength : 1024
Exchange              : DH
HashLength            : 0
Hash                  :
CipherBlockLength     : 16
CipherLength          : 128
BaseCipherSuite       : 158
CipherSuite           : 158
Cipher                : AES
Name                  : TLS_DHE_RSA_WITH_AES_128_GCM_SHA256
Protocols             : {771, 65277}

KeyType               : 0
Certificate           :
MaximumExchangeLength : 0
MinimumExchangeLength : 0
Exchange              :
HashLength            : 0
Hash                  :
CipherBlockLength     : 0
CipherLength          : 0
BaseCipherSuite       : 0
CipherSuite           : 0
Cipher                :
Name                  : TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA384
Protocols             : {}

KeyType               : 0
Certificate           : ECDSA
MaximumExchangeLength : 65536
MinimumExchangeLength : 0
Exchange              : ECDH
HashLength            : 256
Hash                  : SHA256
CipherBlockLength     : 16
CipherLength          : 128
BaseCipherSuite       : 49187
CipherSuite           : 49187
Cipher                : AES
Name                  : TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA256
Protocols             : {771, 65277}

KeyType               : 0
Certificate           : RSA
MaximumExchangeLength : 65536
MinimumExchangeLength : 0
Exchange              : ECDH
HashLength            : 384
Hash                  : SHA384
CipherBlockLength     : 16
CipherLength          : 256
BaseCipherSuite       : 49192
CipherSuite           : 49192
Cipher                : AES
Name                  : TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384
Protocols             : {771, 65277}

KeyType               : 0
Certificate           : RSA
MaximumExchangeLength : 65536
MinimumExchangeLength : 0
Exchange              : ECDH
HashLength            : 256
Hash                  : SHA256
CipherBlockLength     : 16
CipherLength          : 128
BaseCipherSuite       : 49191
CipherSuite           : 49191
Cipher                : AES
Name                  : TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256
Protocols             : {771, 65277}

KeyType               : 0
Certificate           : ECDSA
MaximumExchangeLength : 65536
MinimumExchangeLength : 0
Exchange              : ECDH
HashLength            : 160
Hash                  : SHA1
CipherBlockLength     : 16
CipherLength          : 256
BaseCipherSuite       : 49162
CipherSuite           : 49162
Cipher                : AES
Name                  : TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA
Protocols             : {769, 770, 771, 65279...}

KeyType               : 0
Certificate           : ECDSA
MaximumExchangeLength : 65536
MinimumExchangeLength : 0
Exchange              : ECDH
HashLength            : 160
Hash                  : SHA1
CipherBlockLength     : 16
CipherLength          : 128
BaseCipherSuite       : 49161
CipherSuite           : 49161
Cipher                : AES
Name                  : TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA
Protocols             : {769, 770, 771, 65279...}

KeyType               : 0
Certificate           : RSA
MaximumExchangeLength : 65536
MinimumExchangeLength : 0
Exchange              : ECDH
HashLength            : 160
Hash                  : SHA1
CipherBlockLength     : 16
CipherLength          : 256
BaseCipherSuite       : 49172
CipherSuite           : 49172
Cipher                : AES
Name                  : TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA
Protocols             : {769, 770, 771, 65279...}

KeyType               : 0
Certificate           : RSA
MaximumExchangeLength : 65536
MinimumExchangeLength : 0
Exchange              : ECDH
HashLength            : 160
Hash                  : SHA1
CipherBlockLength     : 16
CipherLength          : 128
BaseCipherSuite       : 49171
CipherSuite           : 49171
Cipher                : AES
Name                  : TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA
Protocols             : {769, 770, 771, 65279...}

KeyType               : 0
Certificate           : RSA
MaximumExchangeLength : 16384
MinimumExchangeLength : 512
Exchange              : RSA
HashLength            : 0
Hash                  :
CipherBlockLength     : 16
CipherLength          : 256
BaseCipherSuite       : 157
CipherSuite           : 157
Cipher                : AES
Name                  : TLS_RSA_WITH_AES_256_GCM_SHA384
Protocols             : {771, 65277}

KeyType               : 0
Certificate           : RSA
MaximumExchangeLength : 16384
MinimumExchangeLength : 512
Exchange              : RSA
HashLength            : 0
Hash                  :
CipherBlockLength     : 16
CipherLength          : 128
BaseCipherSuite       : 156
CipherSuite           : 156
Cipher                : AES
Name                  : TLS_RSA_WITH_AES_128_GCM_SHA256
Protocols             : {771, 65277}

KeyType               : 0
Certificate           : RSA
MaximumExchangeLength : 16384
MinimumExchangeLength : 512
Exchange              : RSA
HashLength            : 256
Hash                  : SHA256
CipherBlockLength     : 16
CipherLength          : 256
BaseCipherSuite       : 61
CipherSuite           : 61
Cipher                : AES
Name                  : TLS_RSA_WITH_AES_256_CBC_SHA256
Protocols             : {771, 65277}

KeyType               : 0
Certificate           : RSA
MaximumExchangeLength : 16384
MinimumExchangeLength : 512
Exchange              : RSA
HashLength            : 256
Hash                  : SHA256
CipherBlockLength     : 16
CipherLength          : 128
BaseCipherSuite       : 60
CipherSuite           : 60
Cipher                : AES
Name                  : TLS_RSA_WITH_AES_128_CBC_SHA256
Protocols             : {771, 65277}

KeyType               : 0
Certificate           : RSA
MaximumExchangeLength : 16384
MinimumExchangeLength : 512
Exchange              : RSA
HashLength            : 160
Hash                  : SHA1
CipherBlockLength     : 16
CipherLength          : 256
BaseCipherSuite       : 53
CipherSuite           : 53
Cipher                : AES
Name                  : TLS_RSA_WITH_AES_256_CBC_SHA
Protocols             : {769, 770, 771, 65279...}

KeyType               : 0
Certificate           : RSA
MaximumExchangeLength : 16384
MinimumExchangeLength : 512
Exchange              : RSA
HashLength            : 160
Hash                  : SHA1
CipherBlockLength     : 16
CipherLength          : 128
BaseCipherSuite       : 47
CipherSuite           : 47
Cipher                : AES
Name                  : TLS_RSA_WITH_AES_128_CBC_SHA
Protocols             : {769, 770, 771, 65279...}

KeyType               : 0
Certificate           : RSA
MaximumExchangeLength : 16384
MinimumExchangeLength : 512
Exchange              : RSA
HashLength            : 160
Hash                  : SHA1
CipherBlockLength     : 8
CipherLength          : 168
BaseCipherSuite       : 10
CipherSuite           : 10
Cipher                : 3DES
Name                  : TLS_RSA_WITH_3DES_EDE_CBC_SHA
Protocols             : {769, 770, 771, 768...}

KeyType               : 0
Certificate           : RSA
MaximumExchangeLength : 16384
MinimumExchangeLength : 512
Exchange              : RSA
HashLength            : 256
Hash                  : SHA256
CipherBlockLength     : 1
CipherLength          : 0
BaseCipherSuite       : 59
CipherSuite           : 59
Cipher                :
Name                  : TLS_RSA_WITH_NULL_SHA256
Protocols             : {771, 65277}

KeyType               : 0
Certificate           : RSA
MaximumExchangeLength : 16384
MinimumExchangeLength : 512
Exchange              : RSA
HashLength            : 160
Hash                  : SHA1
CipherBlockLength     : 1
CipherLength          : 0
BaseCipherSuite       : 2
CipherSuite           : 2
Cipher                :
Name                  : TLS_RSA_WITH_NULL_SHA
Protocols             : {769, 770, 771, 768...}

KeyType               : 0
Certificate           :
MaximumExchangeLength : 0
MinimumExchangeLength : 0
Exchange              :
HashLength            : 0
Hash                  :
CipherBlockLength     : 0
CipherLength          : 0
BaseCipherSuite       : 0
CipherSuite           : 0
Cipher                :
Name                  : TLS_PSK_WITH_AES_256_GCM_SHA384
Protocols             : {}

KeyType               : 0
Certificate           :
MaximumExchangeLength : 256
MinimumExchangeLength : 0
Exchange              : PSK
HashLength            : 0
Hash                  :
CipherBlockLength     : 16
CipherLength          : 128
BaseCipherSuite       : 168
CipherSuite           : 168
Cipher                : AES
Name                  : TLS_PSK_WITH_AES_128_GCM_SHA256
Protocols             : {771, 65277}

KeyType               : 0
Certificate           :
MaximumExchangeLength : 256
MinimumExchangeLength : 0
Exchange              : PSK
HashLength            : 384
Hash                  : SHA384
CipherBlockLength     : 16
CipherLength          : 256
BaseCipherSuite       : 175
CipherSuite           : 175
Cipher                : AES
Name                  : TLS_PSK_WITH_AES_256_CBC_SHA384
Protocols             : {771, 65277}

KeyType               : 0
Certificate           :
MaximumExchangeLength : 256
MinimumExchangeLength : 0
Exchange              : PSK
HashLength            : 256
Hash                  : SHA256
CipherBlockLength     : 16
CipherLength          : 128
BaseCipherSuite       : 174
CipherSuite           : 174
Cipher                : AES
Name                  : TLS_PSK_WITH_AES_128_CBC_SHA256
Protocols             : {771, 65277}

KeyType               : 0
Certificate           :
MaximumExchangeLength : 256
MinimumExchangeLength : 0
Exchange              : PSK
HashLength            : 384
Hash                  : SHA384
CipherBlockLength     : 1
CipherLength          : 0
BaseCipherSuite       : 177
CipherSuite           : 177
Cipher                :
Name                  : TLS_PSK_WITH_NULL_SHA384
Protocols             : {771, 65277}

KeyType               : 0
Certificate           :
MaximumExchangeLength : 256
MinimumExchangeLength : 0
Exchange              : PSK
HashLength            : 256
Hash                  : SHA256
CipherBlockLength     : 1
CipherLength          : 0
BaseCipherSuite       : 176
CipherSuite           : 176
Cipher                :
Name                  : TLS_PSK_WITH_NULL_SHA256
Protocols             : {771, 65277}

[shirhatti]

@tebeco Can you provide us with a wireshark trace so that we can see exactly what is being negotiated? Thanks!

cc @anurse

[tebeco]

What filter would i use to extract what you are looking for, pretty sure i can leak data i don't want too
Also i have a doubt i actually see something :

• With chrome i have no logs out of Kestrel
• With Firefox i got this :

info: Microsoft.AspNetCore.Server.Kestrel[20]
      Connection id "xxxxxxxxxxxxxxxxxxx" request processing ended abnormally.
System.IO.IOException: The decryption operation failed, see inner exception. ---> System.ComponentModel.Win32Exception: An unknown error occurred while processing the certificate.
   --- End of inner exception stack trace ---
   at System.Net.Security.SslStreamInternal.ReadAsyncInternal[TReadAdapter](TReadAdapter adapter, Memory`1 buffer)
   at Microsoft.AspNetCore.Server.Kestrel.Core.Adapter.Internal.AdaptedPipeline.ReadInputAsync(Stream stream)
   at System.IO.Pipelines.PipeCompletion.ThrowLatchedException()
   at System.IO.Pipelines.Pipe.GetReadResult(ReadResult& result)
   at System.IO.Pipelines.Pipe.GetReadAsyncResult()
   at Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Http.HttpProtocol.ProcessRequests[TContext](IHttpApplication`1 application)
   at Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Http.HttpProtocol.ProcessRequestsAsync[TContext](IHttpApplication`1 application)

i guess that for now i'll keep on using Firefox to do a capture but i either choose bad options when installing wireshark (lots of question about loopback/wifi/admin etc ...) and i might have opt_out from too many options

also i tried to use this filter : tcp.port == 5043 (which is supposed to be the Kestrel port)
and i see nothing

[tebeco]

also i did not yes disabled H2, soooo is that normal :

(the double rounded value is a bonus)