Annotate unsupported APIs in System.Net.Security

[buyaa-n]

As part of #47228 running an analyzer to detect APIs throwing PNSE but have not being annotated with the any of Obsolete, SupportedOSPlatform, UnsupportedOSPlatform attributes, we need to annotate them so that developers get warnings when they use them unexpectedly

API	Finding	Reachable platforms	Comment	Suggestion	Location
'NegotiateStreamPal.QueryContextClientSpecifiedSpn(SafeDeleteContext)'	unconditionally throws PNSE	reachable on iOS, OSX, Unix, Android	internal API	Might need unsupported annotations for these platforms	Common\src\System\Net\Security\NegotiateStreamPal.Unix.cs(32,13)
'CipherSuitesPolicyPal.CipherSuitesPolicyPal(IEnumerable)'	unconditionally throws PNSE	reachable on Windows	Internal API used by pulbic constructor CipherSuitesPolicy(IEnumerable allowedCipherSuites)	Add Unsupported on windows	System.Net.Security\src\System\Net\Security\CipherSuitesPolicyPal.Windows.cs(12,13)
'NegotiateStreamPal.QueryContextAssociatedName(SafeDeleteContext?)'	unconditionally throws PNSE	reachable on iOS, OSX, Unix, Android	internal API	Might need unsupported annotations for these platforms	System.Net.Security\src\System\Net\Security\NegotiateStreamPal.Unix.cs(37,13)
'SslStreamPal.Renegotiate(ref SafeFreeCredentials?, ref SafeDeleteSslContext?, SslAuthenticationOptions, out byte[]?)'	unconditionally throws PNSE	reachable on Android	unreferenced internal API	Might be a dead code, or else add annotations	System.Net.Security\src\System\Net\Security\SslStreamPal.Android.cs(50,13)
'SslStreamPal.Renegotiate(ref SafeFreeCredentials?, ref SafeDeleteSslContext?, SslAuthenticationOptions, out byte[]?)'	unconditionally throws PNSE	reachable on iOS, OSX, tvOS	unreferenced internal API	Might be a dead code, or else add annotations	System.Net.Security\src\System\Net\Security\SslStreamPal.OSX.cs(57,13)

cc @jeffhandley @terrajobst @GrabYourPitchforks

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Issue Details

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As part of #47228 running an analyzer to detect APIs throwing PNSE but have not being annotated with the any of Obsolete, SupportedOSPlatform, UnsupportedOSPlatform attributes, we need to annotate them so that developers get warnings when they use them unexpectedly

API	Finding	Reachable platforms	Comment	Suggestion	Location
'NegotiateStreamPal.QueryContextClientSpecifiedSpn(SafeDeleteContext)'	unconditionally throws PNSE	reachable on iOS, OSX, Unix, Android	internal API	Might need unsupported annotations for these platforms	Common\src\System\Net\Security\NegotiateStreamPal.Unix.cs(32,13)
'CipherSuitesPolicyPal.CipherSuitesPolicyPal(IEnumerable)'	unconditionally throws PNSE	reachable on Windows	Internal API used by pulbic constructor CipherSuitesPolicy(IEnumerable allowedCipherSuites)	Add Unsupported on windows	System.Net.Security\src\System\Net\Security\CipherSuitesPolicyPal.Windows.cs(12,13)
'NegotiateStreamPal.QueryContextAssociatedName(SafeDeleteContext?)'	unconditionally throws PNSE	reachable on iOS, OSX, Unix, Android	internal API	Might need unsupported annotations for these platforms	System.Net.Security\src\System\Net\Security\NegotiateStreamPal.Unix.cs(37,13)
'SslStreamPal.Renegotiate(ref SafeFreeCredentials?, ref SafeDeleteSslContext?, SslAuthenticationOptions, out byte[]?)'	unconditionally throws PNSE	reachable on Android	Not sure, unreferenced internal API	Might be a dead code, or else add annotations	System.Net.Security\src\System\Net\Security\SslStreamPal.Android.cs(50,13)
'SslStreamPal.Renegotiate(ref SafeFreeCredentials?, ref SafeDeleteSslContext?, SslAuthenticationOptions, out byte[]?)'	unconditionally throws PNSE	reachable on iOS, OSX, tvOS	Not sure, unreferenced internal API	Might be a dead code, or else add annotations	System.Net.Security\src\System\Net\Security\SslStreamPal.OSX.cs(57,13)

cc @jeffhandley @terrajobst @GrabYourPitchforks

Author:	buyaa-n
Assignees:	-
Labels:	area-System.Net.Security
Milestone:	-

[wfurt]

The Renegotiate shows up as public NegotiateClientCertificateAsync API.

CipherSuitePolicy works on macOS and Linux with certain versions of OpenSSL
https://docs.microsoft.com/en-us/dotnet/api/system.net.security.ciphersuitespolicy.-ctor?view=net-5.0

[ManickaP]

Triage: @jeffhandley How critical is this for 6.0? This is coming in quite hot, 1 week before ZBB.

[jeffhandley]

It's OK to punt this out to 7.0.