Fix HammerDB/PostgreSQL: use hex password to avoid TCL parsing error

Base64 password contains + and = characters which break HammerDB 4.12's
TCL diset command argument parsing. Changed to hex encoding which
produces alphanumeric-only output across all three components that
share the SuperUserPassword:
- HammerDBExecutor
- PostgreSQLServerConfiguration
- SysbenchExecutor

All three must use the same encoding since they share the same
PostgreSQL credential.

This has been the sole cause of HammerDB parse failures since Mar 16
(~1700 errors/day).

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: Alex Williams-Ferreira

VERSION

@@ -1 +1 @@
-3.0.14
+3.0.15

src/VirtualClient/VirtualClient.Actions/HammerDB/HammerDBExecutor.cs

@@ -98,7 +98,7 @@ public string SuperUserPassword
             get
             {
                 byte[] hashBytes = SHA256.HashData(Encoding.UTF8.GetBytes("default"));
-                return Convert.ToBase64String(hashBytes);
+                return Convert.ToHexString(hashBytes);
             }
         }
 

src/VirtualClient/VirtualClient.Actions/Sysbench/SysbenchExecutor.cs

@@ -170,7 +170,7 @@ public string SuperUserPassword
             get
             {
                 byte[] hashBytes = SHA256.HashData(Encoding.UTF8.GetBytes("default"));
-                return Convert.ToBase64String(hashBytes);
+                return Convert.ToHexString(hashBytes);
             }
         }
 

src/VirtualClient/VirtualClient.Dependencies/PostgreSQLServer/PostgreSQLServerConfiguration.cs

@@ -108,7 +108,7 @@ public string SuperUserPassword
             get
             {
                 byte[] hashBytes = SHA256.HashData(Encoding.UTF8.GetBytes("default"));
-                return Convert.ToBase64String(hashBytes);
+                return Convert.ToHexString(hashBytes);
             }
         }