Tracing Code Paths for Fuzz Testing in Bitcoin Core
Fuzz testing, Fuzz testing, navigating through the code.
Understanding Bitcoin Core’s Execution Model
Before diving into tracking code paths, let’s quickly understand how bitcoin core executes functions. Tasks, such as packet processing, transaction verification, and consensus protocol execution. .
Fuzz Testing Frameworks
Fuzz testing, several frameworks have been developed:
.
* Valgrind : a memory debugging tool for detecting leas, crashes, and other memory-related issues. It also includes a set of tools for fuzz testing.
* GCC’s built-in strace command
:
Using Strace with Fuzz Testing
When using strace, it’s essential to start from the beginning of your fuzz test function, as each call will be traced separately. To do this:
1.
2.
`bash
GCC -Std = C99 -G -Wall -wall – -coverage -fsanitize = Address Obj/Core.c -o Core
Valgrind-Leak-Check = Full-Show-Leak-Kinds = All–Sysroot =/Usr–Follow-syms = Core ./core
`
3.
`bash
./core
`
Fuzz Testing Example
To demonstrate how
`C
#Include
uint32_t generatorandom (uint8_t* buffer) {
uint32_t generated;
Yes {
generated = rand ();
} While (generated == 0);
// Introduce an error by modifying the Input Buffer
*(Buffer + 1) = 42;
Return Generated;
}
int Main () {
Const size_t bufsize = 10;
uint8_t Buffer [Bufsize];
uint32_t generated;
// Generate a random number, but introduce an error in the process
generated = generatorandom (buffher);
// Check If the Expected Value Matches
Assert (generated == 42 && Memcmp (Buffer, expected_value, bufsize) == 0);
Return 0;
}
Tracing Code Paths
Usage Paths:
1.
2.
`bash
GCC -Std = C99 -G -Wall -wall – -coverage -fsanitize = Address Obj/Core.c -o Core
Valgrind-Leak-Check = Full-Show-Leak-Kinds = All–Sysroot =/Usr–Follow-syms = Core ./core
`
3.
`bash
./core
`
4.