proxy authentication fails when called from dotnet restore if certain characters are present in the password

[orthoxerox]

Details about Problem

NuGet product used (NuGet.exe | VS UI | Package Manager Console | dotnet.exe):

NuGet version (x.x.x.xxx): 4.3.0.4406

dotnet.exe --version (if appropriate): 2.0.0

VS version (if appropriate): none

OS version (i.e. win10 v1607 (14393.321)): win7 v7601

Worked before? If so, with which NuGet version:

Detailed repro steps so we can see the same problem

1. Be behind a proxy that requires HTTP authentication
2. Have a password with the following characters /;?:)
3. Configure NuGet to use them: nuget config -set http_proxy=http://mycorporateproxy nuget config -set http_proxy.user=myusername nuget config -set http_proxy.password=urlencodedpassword (the password can be urlencoded and escaped (^%) or escaped (^/^;^?^:^), it doesn't matter).
4. Run dotnet add MyProject.csproj package Newtonsoft.Json. It fails. See below
5. When the password is changed to a different one not containing the characters above, dotnet restore works fine.
6. Both curl and maven work fine with the original password

  Writing C:\Users\myusername\AppData\Local\Temp\tmpC8E6.tmp
info : Adding PackageReference for package 'Newtonsoft.Json' into project 'MyProject.csproj'.
log  : Restoring packages for c:\...\MyProject.csproj...
info :   GET https://www.nuget.org/api/v2/FindPackagesById()?id='Newtonsoft.Json'
info :   ProxyAuthenticationRequired https://www.nuget.org/api/v2/FindPackagesById()?id='Newtonsoft.Json' 5843ms
log  : Retrying 'FindPackagesByIdAsyncCore' for source 'https://www.nuget.org/api/v2/FindPackagesById()?id='Newtonsoft.Json''.
log  : Response status code does not indicate success: 407 (Proxy Authentication Required).
info :   GET https://www.nuget.org/api/v2/FindPackagesById()?id='Newtonsoft.Json'
info :   ProxyAuthenticationRequired https://www.nuget.org/api/v2/FindPackagesById()?id='Newtonsoft.Json' 734ms

Sorry the logs are not at the max verbosity, but I am currently not willing to change my corporate pw again to simlate the issue.

[nkolev92]

Hey apologies for the late reply.

At this point it's been a while since this issue was filed. The side-effects of this seem equivalent to dotnet/runtime#26461, so I'm closing this as external.

If you are still seeing similar issues, please open a new issue where you have tried the repro with the updated clients for us to investigate.