Respect configured RSA minimum certificate key size when creating RSA app certificates

[mrsuciu]

Proposed changes

If a minimum RSA certificate key size is specified in the application configuration and no existing RSA application certificate is present the created application RSA certificate will have a key size equal to the specified MinimumCertificateKeySize configuration parameter.

Related Issues

• Fixes SecurityConfiguration certificate key size is not used by ApplicationInstance to generate a new certificate #3512

Types of changes

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• Bugfix (non-breaking change which fixes an issue)
• Enhancement (non-breaking change which adds functionality)
• Test enhancement (non-breaking change to increase test coverage)
• Breaking change (fix or feature that would cause existing functionality to not work as expected, requires version increase of Nuget packages)
• Documentation Update (if none of the other choices apply)

Checklist

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Further comments

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[codecov]

Codecov Report

❌ Patch coverage is 93.33333% with 1 line in your changes missing coverage. Please review.
✅ Project coverage is 60.12%. Comparing base (d25caff) to head (5517316).
⚠️ Report is 103 commits behind head on master.

Files with missing lines	Patch %	Lines
...raries/Opc.Ua.Configuration/ApplicationInstance.cs	93.33%	0 Missing and 1 partial ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #3513      +/-   ##
==========================================
+ Coverage   51.86%   60.12%   +8.25%     
==========================================
  Files         370      378       +8     
  Lines       78618    78930     +312     
  Branches    13650    13736      +86     
==========================================
+ Hits        40779    47456    +6677     
+ Misses      33705    27104    -6601     
- Partials     4134     4370     +236     

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[romanett]

Looks good