Logging

Debugging an application with the freedom of a rich API can lead to flows which are hard to unravel. To aid the user in the debugging process, libdebug provides logging. The logging system is implemented in the submodule liblog and adheres to the Python logging system.

Event Logging

By default, libdebug only prints critical logs such as warnings and errors. However, the user can enable more verbose logging by setting the argv parameter of the script.

The available logging modes for events are:

Mode	Description
`debugger`	Logs related to the debugging operations performed on the process by libdebug.
`pipe`	Logs related to interactions with the process pipe: bytes received and bytes sent.
`dbg`	Combination of the `pipe` and `debugger` options.

pwntools compatibility

As reported in this documentation, the argv parameters passed to libdebug are lowercase. This choice is made to avoid conflicts with pwntools, which intercepts all uppercase arguments.

Debugger Logging

The debugger option displays all logs related to the debugging operations performed on the process by libdebug.

debugger argv option

Pipe Logging

The pipe option, on the other hand, displays all logs related to interactions with the process pipe: bytes received and bytes sent.

pipe argv option

The best of both worlds

The dbg option is the combination of the pipe and debugger options. It displays all logs related to the debugging operations performed on the process by libdebug, as well as interactions with the process pipe: bytes received and bytes sent.

Changing logging levels at runtime

libdebug defines logging levels and information types to allow the user to filter the granularity of the the information they want to see. Logger levels for each event type can be changed at runtime using the libcontext module.

Example of setting logging levels

from libdebug import libcontext

libcontext.general_logger = 'DEBUG'
libcontext.pipe_logger = 'DEBUG'
libcontext.debugger_logger = 'DEBUG'

Logger	Description	Supported Levels	Default Level
`general_logger`	Logger used for general libdebug logs, different from the `pipe` and `debugger` logs.	`DEBUG`, `INFO`, `WARNING`, `SILENT`	`INFO`
`pipe_logger`	Logger used for pipe logs.	`DEBUG`, `SILENT`	`SILENT`
`debugger_logger`	Logger used for debugger logs.	`DEBUG`, `SILENT`	`SILENT`

Let's see what each logging level actually logs:

Log Level	Debug Logs	Information Logs	Warnings
DEBUG
INFO
WARNING
SILENT

Temporary logging level changes

Logger levels can be temporarily changed at runtime using a with statement, as shown in the following example.

from libdebug import libcontext

with libcontext.tmp(pipe_logger='SILENT', debugger_logger='DEBUG'):
    r.sendline(b'gimme the flag')