Removed illegal reflection access in kerberos authentication

[lilgreenbird]

1. Removed illegal reflection access, DNSKerberosLocator will handle validation
2. removed unused test

[codecov-io]

Codecov Report

Merging #839 into dev will increase coverage by 0.29%.
The diff coverage is 0%.

@@             Coverage Diff              @@
##                dev     #839      +/-   ##
============================================
+ Coverage     48.29%   48.58%   +0.29%     
- Complexity     2781     2790       +9     
============================================
  Files           116      116              
  Lines         27877    27867      -10     
  Branches       4651     4649       -2     
============================================
+ Hits          13462    13539      +77     
+ Misses        12200    12127      -73     
+ Partials       2215     2201      -14

Flag	Coverage Δ	Complexity Δ
#JDBC42	48.09% <0%> (+0.28%)	2748 <0> (+8)	⬆️
#JDBC43	48.49% <0%> (+0.26%)	2786 <0> (+7)	⬆️

Impacted Files	Coverage Δ	Complexity Δ
...crosoft/sqlserver/jdbc/dns/DNSKerberosLocator.java	0% <ø> (ø)	0 <0> (ø)	⬇️
...m/microsoft/sqlserver/jdbc/KerbAuthentication.java	0% <0%> (ø)	0 <0> (ø)	⬇️
...om/microsoft/sqlserver/jdbc/ReaderInputStream.java	43.95% <0%> (-3.3%)	15% <0%> (ø)
...m/microsoft/sqlserver/jdbc/SQLServerException.java	75.93% <0%> (-1.51%)	30% <0%> (-1%)
...m/microsoft/sqlserver/jdbc/SQLServerResultSet.java	32.46% <0%> (-0.31%)	253% <0%> (-3%)
...soft/sqlserver/jdbc/SQLServerDatabaseMetaData.java	33.49% <0%> (+0.15%)	63% <0%> (+1%)	⬆️
.../microsoft/sqlserver/jdbc/SQLServerConnection.java	48.09% <0%> (+0.17%)	335% <0%> (+1%)	⬆️
...oft/sqlserver/jdbc/SQLServerPreparedStatement.java	51.96% <0%> (+0.18%)	212% <0%> (ø)	⬇️
...rc/main/java/com/microsoft/sqlserver/jdbc/dtv.java	62.23% <0%> (+0.23%)	0% <0%> (ø)	⬇️
...om/microsoft/sqlserver/jdbc/SQLServerBulkCopy.java	52.58% <0%> (+0.24%)	264% <0%> (+3%)	⬆️
... and 6 more

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[ulvii]

Why was this necessary?

[lilgreenbird]

to make it consistent with the rest of the logging in this file

[ulvii]

cannot

[ulvii]

Please remove this

[pierresouchay]

This code removal will break Kerberos cross DC authentication on many JVMs, most notably on Windows

[ulvii]

Hi @pierresouchay,

Starting from JDK 9, users get a massive warning in their applications complaining about illegal reflective access when doing Kerberos authentication. Unfortunately, it seemed like there was no alternative that would let us preserve the same functionality and we removed the piece of code that contained the reflection. It is, however in our backlog to revisit PR #40 in the future and we would appreciate if you could give us suggestions on how to achieve the same functionality without illegal reflective access.

I should also mention that, the removal of reflection did not break any tests in our test lab and it would be really helpful if you guided us to reproduce the regression with exact test scenario and environment details.

[pierresouchay]

@ulvii Yes, I explained a bit the reason, but it is clear it will break the feature. I will blacklist next versions of the driver in our company then. See my comments here: #918 (comment)