Use full TLS record size for application data on Windows

[rzikm]

Don't reduce MaximumMessage by Header and Trailer sizes (they are not included in the size limit).

Previous behavior led to us not consuming input in multiples of power of 2 which led to unnecessary fragmenting of data into TLS packets. The behavior was most noticeable when using 16kB buffer in calls to Write(Async) functions. Where we would split it into two TLS packets with the latter containing only about 40 B of useful data (see wireshark captures below).

This PR also removes some unsafe annotations on the code path.

WireShark captures (Windows)

before (notice the 135B TLS packets)

after

Benchmarks (Windows)

The LargeReadWriteAsync benchmarks use 64kB buffers, so this PR should reduce the number of encryption calls by 1/5

Method	Job	Toolchain	Mean	Error	StdDev	Median	Min	Max	Ratio	RatioSD	Allocated	Alloc Ratio
ReadWriteAsync	Job-VRYUDS	\pr\corerun.exe	34.00 us	0.366 us	0.343 us	33.91 us	33.44 us	34.71 us	0.99	0.02	-	NA
ReadWriteAsync	Job-GONFII	\main\corerun.exe	34.33 us	0.395 us	0.350 us	34.26 us	33.74 us	35.01 us	1.00	0.00	-	NA
LargeReadWriteAsync	Job-VRYUDS	\pr\corerun.exe	57.22 us	1.710 us	1.969 us	57.91 us	53.08 us	59.97 us	0.88	0.04	491 B	1.01
LargeReadWriteAsync	Job-GONFII	\main\corerun.exe	65.05 us	1.296 us	1.492 us	65.03 us	62.89 us	68.19 us	1.00	0.00	484 B	1.00
ConcurrentReadWrite	Job-VRYUDS	\pr\corerun.exe	1,381.65 us	51.610 us	59.434 us	1,389.42 us	1,266.48 us	1,471.83 us	1.02	0.07	-	0.00
ConcurrentReadWrite	Job-GONFII	\main\corerun.exe	1,367.73 us	75.121 us	83.496 us	1,379.64 us	1,165.86 us	1,469.80 us	1.00	0.00	1 B	1.00
ConcurrentReadWriteLargeBuffer	Job-VRYUDS	\pr\corerun.exe	1,021.83 us	46.291 us	53.309 us	1,032.54 us	895.20 us	1,094.38 us	0.99	0.11	-	0.00
ConcurrentReadWriteLargeBuffer	Job-GONFII	\main\corerun.exe	1,043.22 us	70.858 us	81.600 us	1,038.13 us	838.79 us	1,156.26 us	1.00	0.00	4 B	1.00

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Issue Details

---

Closes #51478.

Author:	rzikm
Assignees:	-
Labels:	area-System.Net.Security
Milestone:	-

[rzikm]

This should wait until #87874 is merged to prevent conflicts. Some parts may be no longer necessary after that change.

[rzikm]

/azp run runtime-libraries-coreclr outerloop

[azure-pipelines]

Azure Pipelines successfully started running 1 pipeline(s).

[wfurt]

LGTM

[rzikm]

Many work items seem to be failing on CI (especially in the outerloop pipeline), but I went through the failures reported for System.Net.Security.Tests and System.Net.Http.Functional.Tests and the console output shows no failures.

@dotnet/dnceng Could you please have a look?

[garath]

Could you please have a look?

We currently have no known ongoing issues.

Please point me to a particular error?

[wfurt]

I'm not sure what @rzikm had in ind. But for example https://helixre107v0xdcypoyl9e7f.blob.core.windows.net/dotnet-runtime-refs-pull-95595-merge-b3746c6d13a44017a0/Common.Tests/1/console.a0e72f3a.log?helixlogtype=result

it seems like the tests executed but it is reported as failure.

category=OuterLoop -notrait category=IgnoreForCI -notrait category=failing  
  Discovering: Common.Tests (method display = ClassAndMethod, method display options = None)
  Discovered:  Common.Tests (found 6 of 268 test cases)
  Starting:    Common.Tests (parallel test collections = on, max threads = 2)
  Finished:    Common.Tests
=== TEST EXECUTION SUMMARY ===
   Common.Tests  Total: 30, Errors: 0, Failed: 0, Skipped: 0, Time: 1.516s

[garath]

Looks like you're also running into #95762. Perhaps connected and something is significantly breaking test reporting in these runs?