Mercurial > dropbear
diff default_options.h @ 1861:2b3a8026a6ce
Add re-exec for server
This allows ASLR to re-randomize the address
space for every connection, preventing some
vulnerabilities from being exploitable by
repeated probing.
Overhead (memory and time) is yet to be confirmed.
At present this is only enabled on Linux. Other BSD platforms
with fexecve() would probably also work though have not been tested.
| author | Matt Johnston <matt@ucc.asn.au> |
|---|---|
| date | Sun, 30 Jan 2022 10:14:56 +0800 |
| parents | 35d504d59c05 |
| children | 40f8468ad4d4 |
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--- a/default_options.h Thu Jan 27 15:09:29 2022 +0800 +++ b/default_options.h Sun Jan 30 10:14:56 2022 +0800 @@ -37,7 +37,14 @@ #define NON_INETD_MODE 1 #define INETD_MODE 1 -/* Include verbose debug output, enabled with -v at runtime. +/* By default Dropbear will re-execute itself for each incoming connection so + that memory layout may be re-randomised (ASLR) - exploiting + vulnerabilities becomes harder. Re-exec causes slightly more memory use + per connection. + This option is ignored on non-Linux platforms at present */ +#define DROPBEAR_REEXEC 1 + +/* Include verbose debug output, enabled with -v at runtime. * This will add a reasonable amount to your executable size. */ #define DEBUG_TRACE 0