Merge pull request #544 from a36579066/lab8

[LAB8] 313554006

Author: YingMuo

lab8/solve.py

@@ -1,11 +1,36 @@
 #!/usr/bin/env python3
 
-import angr,sys
+import angr
+import claripy
+import sys
+
+angr.loggers.disable_root_logger()
+
+def is_flag_found(state):
+    output = state.posix.dumps(1)
+    return b"flag" in output
 
 def main():
-    secret_key = b""
-    sys.stdout.buffer.write(secret_key)
+    # 載入 binary
+    project = angr.Project("./chal", auto_load_libs=False)
+
+    input_len = 100
+    input_bits = claripy.BVS("input", input_len * 8)
+    symbolic_stdin = angr.SimFile("stdin", content=input_bits, size=input_len)
+
+    initial_state = project.factory.entry_state(stdin=symbolic_stdin)
+
+    simgr = project.factory.simgr(initial_state)
+
+    simgr.explore(find=is_flag_found)
 
+    if simgr.found:
+        found = simgr.found[0]
+        solution = found.solver.eval(input_bits, cast_to=bytes)
+        sys.stdout.buffer.write(solution)
+    else:
+        print("No solution found.", file=sys.stderr)
+        sys.exit(1)
 
-if __name__ == '__main__':
+if __name__ == "__main__":
     main()