Fix Authentication in Legacy Windows Game DLL
Budget: $30 – $250 USD
I have an older Windows game client whose DLL no longer satisfies the server’s current handshake rules. The job is to open up that legacy DLL, locate the authentication routine that now fails, and patch the raw assembly so the old client behaves exactly like the latest release and logs in cleanly again.
What I already know
• The break happens at the authentication stage—server drops the connection immediately, so we are dealing with an authentication-failure only.
• Function layout between the old and new DLL has shifted; a direct binary diff shows several offset changes.
• No new features are needed, only a code-level adjustment that matches the new protocol so the login succeeds.
What you’ll do
1. Disassemble the old DLL in IDA, Ghidra, or your preferred tool.
2. Identify and modify the relevant assembly blocks to bring them in line with the new spec—this may involve tweaking arguments, re-pointing calls, or inserting small stubs.
3. Rebuild or patch the binary (no source code available) and verify the client completes the authentication handshake against the live server.
Deliverables (within 24 hours of acceptance)
• Patched DLL ready to drop into the old client folder.
• Short change log explaining what was altered and why.
• Proof-of-success: a brief screen recording or log file showing the legacy client reaching in-game after authentication.
This is a fixed-fee, same-day task—roughly a couple of hours if you already live in IDA/Ghidra and are comfortable with x86 assembly and network handshakes.
What I already know
• The break happens at the authentication stage—server drops the connection immediately, so we are dealing with an authentication-failure only.
• Function layout between the old and new DLL has shifted; a direct binary diff shows several offset changes.
• No new features are needed, only a code-level adjustment that matches the new protocol so the login succeeds.
What you’ll do
1. Disassemble the old DLL in IDA, Ghidra, or your preferred tool.
2. Identify and modify the relevant assembly blocks to bring them in line with the new spec—this may involve tweaking arguments, re-pointing calls, or inserting small stubs.
3. Rebuild or patch the binary (no source code available) and verify the client completes the authentication handshake against the live server.
Deliverables (within 24 hours of acceptance)
• Patched DLL ready to drop into the old client folder.
• Short change log explaining what was altered and why.
• Proof-of-success: a brief screen recording or log file showing the legacy client reaching in-game after authentication.
This is a fixed-fee, same-day task—roughly a couple of hours if you already live in IDA/Ghidra and are comfortable with x86 assembly and network handshakes.