Obfuscation is the act of deliberately converting a piece of source code into codes that are difficult for human to understand to conceal its true purpose, but the functionality remains unchanged and are perfectly executable by computers.
Example
Here is a step by step guide on obfuscating a piece of C code. The transformation before and after are quite drastic as compared to each other.
Before Obfuscation
hello.c
int main(void)
{
time_t t;
struct tm* tm;
t = time(NULL); /* Get current time in seconds */
tm = localtime(&t); /* Transform a timestamp to broken-down time */
switch(tm->tm_hour) /* Choose action from the hour value */
{
case 4: case 5: case 6: case 7:
case 8: case 9: case 10: case 11:
printf("Good morning!\n");
break;
case 12: case 13: case 14:
printf("Good day!\n");
break;
case 15: case 16: case 17:
printf("Good afternoon!\n");
break;
case 18: case 19: case 20: case 21:
printf("Good evening!\n");
break;
default:
printf("Good night!\n");
break;
}
return 0;
}After Obfuscation
hello.c
#include <time.h>
char* w = "AAAA########+++///9999AA Good %s!\n\0morning\0day\0afternoon\0evening\0night";
int main(){time_t t=time(0); return printf(w+25, w + w[ localtime(&t)->tm_hour ]);}Online Obfuscator
Obfuscator is also available online for JavaScript and Python. Google the related keywords for more similar services.
Disadvantages
- Obfuscation makes reading or reverse-engineering difficult, but not impossible
- May causes the performance to degrade if not handled properly
- Introduces complexity for building and debugging to the developers
References
University of Florida. Obfuscated C Code. Retrieved 2024, March 25 from https://www.cise.ufl.edu/~manuel/obfuscate/obfuscate.html