Merge branch 'sploit/symtbl-base'

This branch brings some conveniences to the semantics behind Symtbl base
values.

* sploit/symtbl-base:
  sploit: rev: Properly base Symtbls for non-PIC binaries
  sploit: Fix bugs involving Symtbl base value
  sploit: mem: Allow Symtbl base to be modified

2 files changed, 15 insertions, 8 deletions

diff --git a/sploit/mem.py b/sploit/mem.py
index 3fee92f..3a3e697 100644
--- a/sploit/mem.py
+++ b/sploit/mem.py
@@ -1,8 +1,8 @@
 import types
 
 class Symtbl:
-    def __init__(self, **kwargs):
-        object.__setattr__(self, '_namesp', types.SimpleNamespace(base=0,sym={},sub={}))
+    def __init__(self, *, base=0, **kwargs):
+        object.__setattr__(self, '_namesp', types.SimpleNamespace(base=base,sym={},sub={}))
         for k, v in {**kwargs}.items():
             setattr(self, k, v)
 
@@ -15,11 +15,13 @@ class Symtbl:
 
     def __setattr__(self, ident, value):
         if ident in dir(self): raise Exception(f'Symtbl: assignment would shadow non-symbol "{ident}"')
-        if ident == 'base': raise Exception('Symtbl: may not redefine symbol "base"')
         self = self._namesp
-        if type(value) is tuple: self.sub[ident], off = value
-        else: off = value
-        self.sym[ident] = off - self.base
+        if ident == 'base':
+            self.base = value
+        else:
+            if type(value) is tuple: self.sub[ident], off = value
+            else: off = value
+            self.sym[ident] = off - self.base
 
     def map(self, addr, off=0):
         self = self._namesp
@@ -34,7 +36,7 @@ class Symtbl:
             self.sym[k] = v + off
 
     def rebase(self, off):
-        self.adjust(-off)
+        self.adjust(self.base - off)
 
     def __str__(_self):
         FMT = '\n{:<20} {:<20}'
diff --git a/sploit/rev/r2.py b/sploit/rev/r2.py
index bb3edb3..6dfd499 100644
--- a/sploit/rev/r2.py
+++ b/sploit/rev/r2.py
@@ -13,6 +13,11 @@ def get_elf_symbols(elf):
     ilog(f'Retrieving symbols of {elf} with r2...')
     out = {}
 
+    cmd_base = 'iI~baddr'
+    base = run_cmd(elf,cmd_base)
+    base = re.split(r'\s+',base[0])[1]
+    base = int(base,0)
+
     cmd_syms = 'is'
     out_syms = run_cmd(elf,cmd_syms)
     out_syms = [re.split(r'\s+',sym) for sym in out_syms][4:]
@@ -39,7 +44,7 @@ def get_elf_symbols(elf):
     out_strs = {sym[2][sym[2].rfind('.')+1:]:int(sym[0],0) for sym in out_strs}
     out.update(out_strs)
 
-    return Symtbl(**out)
+    return Symtbl(base=base, **out)
 
 def get_locals(binary,func):
     ilog(f'Retrieving local stack frame of {hex(func)} in {binary} with r2...')