fix S2325: Methods and properties that don't access instance data should be static

This one is pretty redundant with CA1822 (which is also disabled in the
tests).

It caught a few more cases in the library itself, most of which can't
be changed because they are public API.

https://rules.sonarsource.com/csharp/RSPEC-2325/

src/Renci.SshNet/Security/Cryptography/Bcrypt.cs

@@ -15,6 +15,7 @@
 // OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 
 using Renci.SshNet.Abstractions;
+
 using System;
 using System.Diagnostics;
 using System.Security.Cryptography;
@@ -902,7 +903,7 @@ namespace Renci.SshNet.Security.Cryptography
         /// <param name="b1"></param>
         /// <param name="others"></param>
         /// <returns></returns>
-        private byte[] AppendArrays(byte[] b1, params byte[][] others)
+        private static byte[] AppendArrays(byte[] b1, params byte[][] others)
         {
             //from https://stackoverflow.com/questions/46534429/how-to-convert-java-messagedigest-with-two-update-statements-to-c-sharp
             int n = b1.Length;

src/Renci.SshNet/Session.cs

@@ -316,7 +316,9 @@ namespace Renci.SshNet
         /// <value>
         /// The client version.
         /// </value>
+#pragma warning disable S2325 // Methods and properties that don't access instance data should be static
         public string ClientVersion
+#pragma warning restore S2325 // Methods and properties that don't access instance data should be static
         {
             get
             {

src/Renci.SshNet/ShellStream.cs

@@ -605,7 +605,9 @@ namespace Renci.SshNet
         /// <returns>
         /// The text available in the shell up to and including the expected expression.
         /// </returns>
+#pragma warning disable S2325 // Methods and properties that don't access instance data should be static
         public string? EndExpect(IAsyncResult asyncResult)
+#pragma warning restore S2325 // Methods and properties that don't access instance data should be static
         {
             return TaskToAsyncResult.End<string?>(asyncResult);
         }

test/Renci.SshNet.IntegrationBenchmarks/.editorconfig

@@ -14,6 +14,9 @@ dotnet_diagnostic.S1118.severity = suggestion
 # https://rules.sonarsource.com/csharp/RSPEC-1450/
 dotnet_diagnostic.S1450.severity = suggestion
 
+# S2325: Methods and properties that don't access instance data should be static
+dotnet_diagnostic.S2325.severity = silent
+
 # S4144: Methods should not have identical implementations
 # https://rules.sonarsource.com/csharp/RSPEC-4144/
 dotnet_diagnostic.S4144.severity = suggestion

test/Renci.SshNet.IntegrationTests/.editorconfig

@@ -22,6 +22,9 @@ dotnet_diagnostic.S1155.severity = silent
 # https://rules.sonarsource.com/csharp/RSPEC-1607/
 dotnet_diagnostic.S1607.severity = silent
 
+# S2325: Methods and properties that don't access instance data should be static
+dotnet_diagnostic.S2325.severity = silent
+
 # S2925: "Thread.Sleep" should not be used in tests
 # https://rules.sonarsource.com/csharp/RSPEC-2925/
 dotnet_diagnostic.S2925.severity = silent

test/Renci.SshNet.TestTools.OpenSSH/.editorconfig

@@ -1,5 +1,10 @@
 [*.cs]
 
+#### Sonar rules ####
+
+# S2325: Methods and properties that don't access instance data should be static
+dotnet_diagnostic.S2325.severity = silent
+
 #### Meziantou.Analyzer rules ####
 
 # MA0001: StringComparison is missing

test/Renci.SshNet.Tests/.editorconfig

@@ -34,6 +34,9 @@ dotnet_diagnostic.S2187.severity = silent
 # https://rules.sonarsource.com/csharp/RSPEC-2292/
 dotnet_diagnostic.S2292.severity = silent
 
+# S2325: Methods and properties that don't access instance data should be static
+dotnet_diagnostic.S2325.severity = silent
+
 # S2925: "Thread.Sleep" should not be used in tests
 # https://rules.sonarsource.com/csharp/RSPEC-2925/
 dotnet_diagnostic.S2925.severity = silent