Bug 46382 - Fails to verify some Let's Encrypt Certificates but not others; OpenSSL works for both
Summary: Fails to verify some Let's Encrypt Certificates but not others; OpenSSL works...
Status: NEW
Alias: None
Product: Class Libraries
Classification: Mono
Component: System.Security ()
Version: 4.6.0 (C8)
Hardware: PC Linux
: --- normal
Target Milestone: Untriaged
Assignee: Martin Baulig
Depends on:
Reported: 2016-11-03 15:46 UTC by infinity0
Modified: 2016-11-03 15:57 UTC (History)
2 users (show)

Is this bug a regression?: ---
Last known good build:

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Description infinity0 2016-11-03 15:46:27 UTC

$ mono --version
Mono JIT compiler version 4.6.1 (Debian
Copyright (C) 2002-2014 Novell, Inc, Xamarin Inc and Contributors. www.mono-project.com
	TLS:           __thread
	SIGSEGV:       altstack
	Notifications: epoll
	Architecture:  amd64
	Disabled:      none
	Misc:          softdebug 
	LLVM:          supported, not enabled.
	GC:            sgen

and after running 

$ cert-sync /etc/ssl/certs/ca-certificates.crt

as described on


then using the tlstest from here:


We get:

$ ./tlstest.exe https://www.abc-raid.co.uk

# no errors

$ ./tlstest.exe https://www.darkfasel.net

FAILED: #-2146232800
System.IO.IOException: The authentication or decryption has failed. ---> System.IO.IOException: The authentication or decryption has failed. ---> Mono.Security.Protocol.Tls.TlsException: The authentication or decryption has failed.
  at Mono.Security.Protocol.Tls.RecordProtocol.EndReceiveRecord (System.IAsyncResult asyncResult) [0x00040] in <e220be0b0a364427860ee43376ab6f2b>:0 
  at Mono.Security.Protocol.Tls.SslClientStream.SafeEndReceiveRecord (System.IAsyncResult ar, System.Boolean ignoreEmpty) [0x00000] in <e220be0b0a364427860ee43376ab6f2b>:0 
  at Mono.Security.Protocol.Tls.SslClientStream.NegotiateAsyncWorker (System.IAsyncResult result) [0x00071] in <e220be0b0a364427860ee43376ab6f2b>:0 
   --- End of inner exception stack trace ---
  at Mono.Security.Protocol.Tls.SslClientStream.EndNegotiateHandshake (System.IAsyncResult result) [0x0003b] in <e220be0b0a364427860ee43376ab6f2b>:0 
  at Mono.Security.Protocol.Tls.SslStreamBase.AsyncHandshakeCallback (System.IAsyncResult asyncResult) [0x0000c] in <e220be0b0a364427860ee43376ab6f2b>:0 
   --- End of inner exception stack trace ---
  at Mono.Security.Protocol.Tls.SslStreamBase.EndNegotiateHandshake (Mono.Security.Protocol.Tls.SslStreamBase+InternalAsyncResult asyncResult) [0x00028] in <e220be0b0a364427860ee43376ab6f2b>:0 
  at Mono.Security.Protocol.Tls.SslStreamBase.NegotiateHandshake () [0x00035] in <e220be0b0a364427860ee43376ab6f2b>:0 
  at Mono.Security.Protocol.Tls.SslStreamBase.Write (System.Byte[] buffer, System.Int32 offset, System.Int32 count) [0x00076] in <e220be0b0a364427860ee43376ab6f2b>:0 
  at System.IO.StreamWriter.Flush (System.Boolean flushStream, System.Boolean flushEncoder) [0x00094] in <dca3b561b8ad4f9fb10141d81b39ff45>:0 
  at System.IO.StreamWriter.Flush () [0x00006] in <dca3b561b8ad4f9fb10141d81b39ff45>:0 
  at TlsTest.GetStreamPage (System.String url) [0x000c2] in <7ad9caa5280c42fa9e47b5cc3d9b1e0e>:0 
  at TlsTest.Main (System.String[] args) [0x002aa] in <7ad9caa5280c42fa9e47b5cc3d9b1e0e>:0 

You can see more details of the certs here:


Also running `openssl s_client` correctly verifies both of them.