Get sane string behavior by implementing pwndbg.memory.string

pwndbg/auxv.py

@@ -248,4 +248,5 @@ def get_execfn():
         addr -= 1
 
     v = pwndbg.strings.get(addr, 1024)
-    return os.path.abspath(v)
+    if v:
+        return os.path.abspath(v)

pwndbg/memory.py

@@ -68,6 +68,16 @@ def poke(address):
     except: return False
     return True
 
+def string(addr):
+    data = bytearray()
+    while peek(addr):
+        byte = read(addr, 1)
+        if byte == b'\x00':
+            break
+        data += byte
+        addr += 1
+    return data
+
 def byte(addr):   return readtype(pwndbg.typeinfo.uchar, addr)
 def uchar(addr):  return readtype(pwndbg.typeinfo.uchar, addr)
 def ushort(addr): return readtype(pwndbg.typeinfo.ushort, addr)

pwndbg/strings.py

@@ -9,6 +9,7 @@ import string
 
 import gdb
 import pwndbg.events
+import pwndbg.memory
 import pwndbg.typeinfo
 
 length = 15
@@ -32,20 +33,14 @@ def get(address, maxlen = None):
         maxlen = length
 
     try:
-        sz = gdb.Value(address)
+        sz = pwndbg.memory.string(address)
-        sz = sz.cast(pwndbg.typeinfo.pchar)
+        sz = sz.decode('latin-1', 'replace')
-        sz = sz.string('ascii', 'replace', maxlen)
-        sz = pwndbg.memory.read(address, len(sz))
-        sz = sz.rstrip('\x00')
 
         if not sz or not all(s in string.printable for s in sz):
             return None
-
-        sz = str(sz)
     except Exception as e:
         return None
 
-
     if len(sz) < maxlen:
     	return sz