OpenSSH kexgex.c source code analysis:
- KEXINIT payload stored without SSH_MSG_KEXINIT type byte
- Exchange hash prepends SSH_MSG_KEXINIT byte (20) with adjusted length
Before fix:
- client_kexinit_payload included SSH_MSG_KEXINIT byte
- Direct use without prepending
After fix:
- Remove SSH_MSG_KEXINIT byte from payload
- Prepend byte (20) in exchange hash with length+1
- Both kex_exchange.rs and kex_complete.rs updated
Testing result: MAC still fails, indicating additional encoding issues
Next: Detailed comparison of all exchange hash components
4778081866