feat: gRPC TLS support

[godexsoft]

High Level Overview of Change

This PR enhances the gRPC server with optional TLS and mTLS support.

Context of Change

Type of Change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Refactor (non-breaking change that only restructures code)
• Performance (increase or change in throughput and/or latency)
• Tests (you added tests for code that already exists, or your new feature included in this PR)
• Documentation update
• Chore (no impact to binary, e.g. .gitignore, formatting, dropping support for older tooling)
• Release

API Impact

• Public API: New feature (new methods and/or new fields)
• Public API: Breaking change (in general, breaking changes should only impact the next api_version)
• libxrpl change (any change that may affect libxrpl or dependents of libxrpl)
• Peer protocol change (must be backward compatible or bump the peer protocol version)

[Copilot]

Pull request overview

Adds optional TLS configuration to the gRPC server and updates tests/docs to support TLS/mTLS scenarios.

Changes:

• Parse ssl_cert/ssl_key/ssl_chain from [port_grpc] and build gRPC server credentials accordingly.
• Add envconfig helpers to generate TLS-enabled gRPC configs for tests.
• Add a new unit test suite plus example config documentation for gRPC TLS settings.

Reviewed changes

Copilot reviewed 6 out of 6 changed files in this pull request and generated 8 comments.

Show a summary per file

File	Description
src/xrpld/app/main/GRPCServer.h	Stores TLS config paths and declares a credentials factory helper.
src/xrpld/app/main/GRPCServer.cpp	Reads TLS settings from config and switches gRPC listener credentials to TLS when configured.
src/test/jtx/impl/envconfig.cpp	Adds helper functions to populate TLS fields in test configs.
src/test/jtx/envconfig.h	Declares the new TLS-related envconfig helpers.
src/test/app/GRPCServerTLS_test.cpp	Introduces tests intended to cover TLS and “mTLS” gRPC startup paths.
cfg/xrpld-example.cfg	Documents the new [port_grpc] TLS settings and provides example values.

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[Copilot]

Pull request overview

Copilot reviewed 7 out of 7 changed files in this pull request and generated 5 comments.

Comments suppressed due to low confidence (1)

src/xrpld/app/main/GRPCServer.cpp:10

• #include <boost/filesystem.hpp> appears to be unused in this file (no boost::filesystem symbols are referenced). Consider removing it to reduce compile time and avoid unnecessary dependencies (FileUtilities.h already brings in the needed Boost types).

namespace xrpl {

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[codecov]

Codecov Report

❌ Patch coverage is 96.10390% with 3 lines in your changes missing coverage. Please review.
✅ Project coverage is 80.2%. Comparing base (0976b2b) to head (e98fd4e).

Files with missing lines	Patch %	Lines
src/xrpld/app/main/GRPCServer.cpp	96.1%	3 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff            @@
##           develop   #6374     +/-   ##
=========================================
+ Coverage     80.0%   80.2%   +0.2%     
=========================================
  Files          846     846             
  Lines        65700   65774     +74     
  Branches      7257    7181     -76     
=========================================
+ Hits         52547   52730    +183     
+ Misses       13153   13044    -109     

Files with missing lines	Coverage Δ
src/xrpld/app/main/GRPCServer.h	100.0% <ø> (ø)
src/xrpld/app/main/GRPCServer.cpp	81.6% <96.1%> (+38.0%)	⬆️

... and 11 files with indirect coverage changes

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[Copilot]

Pull request overview

Copilot reviewed 7 out of 7 changed files in this pull request and generated 2 comments.

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[Copilot]

Pull request overview

Copilot reviewed 6 out of 6 changed files in this pull request and generated 6 comments.

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