builder: Rename package to payload and expose contents

This follows in the package contents export change.  Additionally, the
builder package is renamed to "payload".

"payload" is actually the preferred name of this package.  It was
previously renamed due to the absurdity of importing
"sploit.payload.payload.Payload()", and the fact that additional modules
were being bundled together so a more broad name _seemed_ desirable.

Signed-off-by: Malfurious <m@lfurio.us>

1 files changed, 94 insertions, 0 deletions

diff --git a/sploit/payload/payload.py b/sploit/payload/payload.py
new file mode 100644
index 0000000..cf105c6
--- /dev/null
+++ b/sploit/payload/payload.py
@@ -0,0 +1,94 @@
+from sploit.arch import arch, itob
+from sploit.symtbl import Symtbl
+
+class Payload:
+    MAGIC = b'\xef'
+
+    def __init__(self, **kwargs):
+        self.payload = b''
+        self.sym = Symtbl(**kwargs)
+        self.ctrs = {}
+
+    def __len__(self):
+        return len(self.payload)
+
+    def __call__(self, badbytes=b''):
+        found = [ hex(x) for x in set(self.payload).intersection(badbytes) ]
+        if len(found) > 0:
+            raise Exception(f'Payload: bad bytes in content: {found}')
+        return self.payload
+
+    def _name(self, kind, sym):
+        if sym is not None: return sym
+        try: ctr = self.ctrs[kind]
+        except: ctr = 0
+        self.ctrs[kind] = ctr + 1
+        return f'{kind}_{ctr}'
+
+    def _append(self, value, sym):
+        (self.sym @ 0)[sym] = len(self)
+        self.payload += value
+        return self
+
+    def _prepend(self, value, sym):
+        self.sym >>= len(value)
+        (self.sym @ 0)[sym] = 0
+        self.payload = value + self.payload
+        return self
+
+    def end(self):
+        return self.sym.base + len(self)
+
+    def bin(self, *values, sym=None):
+        return self._append(b''.join(values), sym=self._name('bin', sym))
+
+    def str(self, *values, sym=None):
+        values = [ v.encode() + b'\x00' for v in values ]
+        return self.bin(*values, sym=self._name('str', sym))
+
+    def int(self, *values, sym=None):
+        values = [ itob(v) for v in values ]
+        return self.bin(*values, sym=self._name('int', sym))
+
+    def int8(self, *values, sym=None):
+        values = [ itob(v, 1) for v in values ]
+        return self.bin(*values, sym=self._name('int', sym))
+
+    def int16(self, *values, sym=None):
+        values = [ itob(v, 2) for v in values ]
+        return self.bin(*values, sym=self._name('int', sym))
+
+    def int32(self, *values, sym=None):
+        values = [ itob(v, 4) for v in values ]
+        return self.bin(*values, sym=self._name('int', sym))
+
+    def int64(self, *values, sym=None):
+        values = [ itob(v, 8) for v in values ]
+        return self.bin(*values, sym=self._name('int', sym))
+
+    def ret(self, *values, sym=None):
+        return self.int(*values, sym=self._name('ret', sym))
+
+    def sbp(self, *values, sym=None):
+        if len(values) == 0:
+            return self.rep(self.MAGIC, arch.wordsize, sym=self._name('sbp', sym))
+        return self.int(*values, sym=self._name('sbp', sym))
+
+    def rep(self, value, size, sym=None):
+        return self.bin(self._rep_helper(value, size), sym=self._name('rep', sym))
+
+    def pad(self, size, value=None, sym=None):
+        return self.bin(self._pad_helper(size, value), sym=self._name('pad', sym))
+
+    def pad_front(self, size, value=None, sym=None):
+        return self._prepend(self._pad_helper(size, value), sym=self._name('pad', sym))
+
+    def _rep_helper(self, value, size, *, explain=''):
+        if size < 0:
+            raise Exception(f'Payload: {explain}rep: available space is negative')
+        if (size := size / len(value)) != int(size):
+            raise Exception(f'Payload: {explain}rep: element does not divide the space evenly')
+        return value * int(size)
+
+    def _pad_helper(self, size, value):
+        return self._rep_helper(value or arch.nopcode, size - len(self), explain='pad: ')