Skip to content

Commit

Permalink
add/fix support for struct "slop" and allow for self-defined alignements
Browse files Browse the repository at this point in the history
  • Loading branch information
@bdcht
bdcht committed Mar 27, 2019
1 parent 162ec00 commit ba269d3
Show file tree
Hide file tree
Showing 4 changed files with 150 additions and 65 deletions.
22 changes: 11 additions & 11 deletions amoco/system/imx6.py
View file
Original file line number Diff line number Diff line change
Expand Up @@ -86,7 +86,7 @@
B : tag
H :> length
B : version
""")
""",packed=True)
class HAB_Header(StructFormatter):
order = '<'
def __init__(self,data="",offset=0):
Expand All @@ -109,7 +109,7 @@ def token_ver_format(k,x,cls=None):
I : self
I : csf
I : reserved2
""")
""",packed=True)
class IVT(StructFormatter):
order = '<'
def __init__(self,data="",offset=0):
Expand All @@ -127,7 +127,7 @@ def __init__(self,data="",offset=0):
I : start
I : size
I : plugin
""")
""",packed=True)
class BootData(StructFormatter):
order = '<'
def __init__(self,data="",offset=0):
Expand All @@ -146,7 +146,7 @@ def __init__(self,data="",offset=0):
I : unk_flags
H :> nlen
H :> elen
""")
""",packed=True)
class PublicKey(StructFormatter):
order = '<'
def __init__(self,data="",offset=0):
Expand All @@ -169,7 +169,7 @@ def size(self):

@StructDefine("""
HAB_Header : header
""")
""",packed=True)
class CRT(StructFormatter):
def __init__(self,data="",offset=0):
self.keys = []
Expand Down Expand Up @@ -200,7 +200,7 @@ def size(self):

@StructDefine("""
HAB_Header : header
""")
""",packed=True)
class CSF(StructFormatter):
def __init__(self,data="",offset=0):
self.cmds = []
Expand Down Expand Up @@ -248,7 +248,7 @@ def CMD(data,offset):
B : par
I : address
I : mask
""")
""",packed=True)
class CheckData(StructFormatter):
order = '<'
def __init__(self,data="",offset=0):
Expand Down Expand Up @@ -279,7 +279,7 @@ def size(self):
B : cmd
H :> len
B : und
""")
""",packed=True)
class NOP(StructFormatter):
order = '<'
def __init__(self,data="",offset=0):
Expand All @@ -291,7 +291,7 @@ def __init__(self,data="",offset=0):
B : cmd
H :> len
B : eng
""")
""",packed=True)
class Unlock(StructFormatter):
order = '<'
def __init__(self,data="",offset=0):
Expand Down Expand Up @@ -325,7 +325,7 @@ def size(self):
B : src
B : tgt
I :> key_dat
""")
""",packed=True)
class InstallKey(StructFormatter):
order = '<'
def __init__(self,data="",offset=0):
Expand Down Expand Up @@ -362,7 +362,7 @@ def size(self):
B : eng
B : cfg
I :> aut_start
""")
""",packed=True)
class Authenticate(StructFormatter):
order = '<'
def __init__(self,data="",offset=0):
Expand Down
167 changes: 118 additions & 49 deletions amoco/system/structs.py
View file
Original file line number Diff line number Diff line change
Expand Up @@ -164,27 +164,33 @@ class Field(object):
pack (value,order='<') : packs the value with the given order and returns the
byte string according to type typename.
"""
def __init__(self,ftype,fcount=0,fname=None,forder=None,fcomment=''):
def __init__(self,ftype,fcount=0,fname=None,forder=None,falign=0,fcomment=''):
self.typename = ftype
self.type_private = isinstance(ftype,(StructCore))
self.count = fcount
self.name = fname
self.order = forder
self.order = forder or '<'
self._align_value = None
if falign:
self.align_value = falign
self.comment = fcomment
@property
def type(self):
if self.type_private:
return self.typename
cls = StructDefine.All[self.typename]
return cls()
try:
cls = StructDefine.All[self.typename]
except KeyError:
return None
else:
return cls()
def format(self):
fmt = self.type.format()
sz = struct.calcsize(fmt)
if self.count>0: sz = sz*self.count
sz = self.size()
return '%ds'%sz
@property
def size(self):
return struct.calcsize(self.format())
sz = self.type.size()
if self.count>0: sz = sz*self.count
return sz
@property
def source(self):
res = "%s"%self.typename
Expand All @@ -193,29 +199,39 @@ def source(self):
if self.comment: res += " ;%s"%self.comment
return res
def __len__(self):
return self.size
def unpack(self,data,offset=0,order='<'):
if self.order: order=self.order
blob = self.type.unpack(data,offset,order)
sz = len(self.type)
return self.size()
@property
def align_value(self):
if self._align_value: return self._align_value
if isinstance(self.type,Field): return self.type.align_value
return self.type.align_value()
@align_value.setter
def align_value(self,val):
self._align_value = val
def align(self,offset):
A = self.align_value
r = offset%A
if r==0: return offset
return offset+(A-r)
def unpack(self,data,offset=0):
blob = self.type.unpack(data,offset)
sz = self.type.size()
count = self.count
if count>0:
blob = [blob]
count -= 1
offset += sz
while count>0:
blob.append(self.type.unpack(data,offset,order))
blob.append(self.type.unpack(data,offset))
offset += sz
count -= 1
return blob
def get(self,data,offset=0,order='<'):
if self.order: order=self.order
return (self.name,self.unpack(data,offset,order))
def pack(self,value,order='<'):
if self.order: order=self.order
def get(self,data,offset=0):
return (self.name,self.unpack(data,offset))
def pack(self,value):
if self.count>0:
return b''.join([struct.pack(order+self.format(),v) for v in value])
return struct.pack(order+self.format(),value)
return b''.join([self.type.pack(v) for v in value])
return self.type.pack(value)
def __call__(self):
return self
def __repr__(self):
Expand All @@ -237,14 +253,20 @@ class RawField(Field):
def format(self):
fmt = self.typename
if self.count==0: return fmt
sz = struct.calcsize(fmt)*self.count
return '%ds'%sz
def unpack(self,data,offset=0,order='<'):
if self.order: order=self.order
return '%d%s'%(sz,fmt)
def size(self):
sz = struct.calcsize(self.typename)
if self.count>0: sz = sz*self.count
return sz
def unpack(self,data,offset=0):
pfx = '%d'%self.count if self.count>0 else ''
res = struct.unpack(order+pfx+self.typename,data[offset:offset+self.size])
res = struct.unpack(self.order+pfx+self.typename,data[offset:offset+self.size()])
if self.count==0 or self.typename=='s': return res[0]
return res
def pack(self,value):
pfx = '%d'%self.count if self.count>0 else ''
res = struct.pack(self.order+pfx+self.typename,value)
return res
def __repr__(self):
fmt = self.typename
r = '<Field %s [%s]'%(self.name,fmt)
Expand All @@ -260,6 +282,11 @@ class StructDefine(object):
"""
All = {}
rawtypes = ('x','c','b','B','h','H','i','I','l','L','f','d','s','n','N','p','P','q','Q')
alignments = {'x':1, 'c':1, 'b':1, 'B':1, 's':1,
'h':2, 'H':2,
'i':4, 'I':4, 'l':4, 'L':4, 'f':4,
'q':8, 'Q':8, 'd':8,
'P':8}
integer = pp.Regex(r'[1-9][0-9]*')
number = integer
number.setParseAction(lambda r: int(r[0]))
Expand All @@ -273,17 +300,28 @@ class StructDefine(object):
def __init__(self,fmt,**kargs):
self.fields = []
self.source = fmt
self.packed = kargs.get('packed',False)
if 'alignments' in kargs:
self.alignments = kargs['alignments']
for l in self.structfmt.parseString(fmt,True):
f_type,f_name,f_comment = l
f_order,f_name = f_name
f_type,f_count = f_type
f_cls = RawField if f_type in self.rawtypes else Field
if f_type in kargs: f_type = kargs[f_type]
self.fields.append(f_cls(f_type,f_count,f_name,f_order,f_comment))
if f_order is None and 'order' in kargs:
f_order=kargs['order']
if f_type in self.rawtypes:
f_cls = RawField
f_align = self.alignments[f_type]
else:
f_cls = Field
f_type = kargs.get(f_type,f_type)
f_align = 0
self.fields.append(f_cls(f_type,f_count,f_name,f_order,f_align,f_comment))
def __call__(self,cls):
self.All[cls.__name__] = cls
cls.fields = self.fields
cls.source = self.source
cls.packed = self.packed
return cls

class UnionDefine(StructDefine):
Expand All @@ -293,13 +331,18 @@ def __call__(self,cls):
self.All[cls.__name__] = cls
cls.fields = self.fields
cls.source = self.source
s = [f.size for f in cls.fields]
s = [f.size() for f in cls.fields]
cls.union = s.index(max(s))
return cls

def TypeDefine(newname, typebase, typecount=0):
f_cls = RawField if typebase in StructDefine.rawtypes else Field
StructDefine.All[newname] = f_cls(typebase,fcount=typecount,fname='typedef')
def TypeDefine(newname, typebase, typecount=0,align_value=0):
if typebase in StructDefine.rawtypes:
f_cls = RawField
f_align = align_value or StructDefine.alignments[typebase]
else:
f_cls = Field
f_align = 0
StructDefine.All[newname] = f_cls(typebase,fcount=typecount,falign=f_align,fname='typedef')

class StructCore(object):
"""StructCore is a ParentClass for all user-defined structures based on a StructDefine format.
Expand All @@ -308,42 +351,68 @@ class StructCore(object):
Note: It is mandatory that any class that inherits from StructCore can be instanciated
with no arguments.
"""
order = '@'
packed = False
union = False

@classmethod
def format(cls):
if cls.union is False:
return cls.order+(''.join((f.format() for f in cls.fields)))
return ''.join((f.format() for f in cls.fields))
else:
return cls.order+cls.fields[cls.union].format()
return cls.fields[cls.union].format()
@classmethod
def size(cls):
return struct.calcsize(cls.format())
A = cls.align_value()
sz = 0
for f in cls.fields:
if cls.union is False and not cls.packed:
sz = f.align(sz)
if cls.union is False:
sz += f.size()
elif f.size>sz:
sz = f.size()
r = sz%A
if (not cls.packed) and r>0:
sz += (A-r)
return sz
def __len__(self):
return self.size()
def unpack(self,data,offset=0,order=None):
@classmethod
def align_value(cls):
return max([f.align_value for f in cls.fields])
def unpack(self,data,offset=0):
for f in self.fields:
setattr(self,f.name,f.unpack(data,offset,order or self.order))
if self.union is False and not self.packed:
offset = f.align(offset)
setattr(self,f.name,f.unpack(data,offset))
if self.union is False:
offset += f.size
offset += f.size()
return self
def pack(self,data=None):
if data is None:
data = [getattr(self,f.name) for f in self.fields]
parts = []
offset = 0
for f,v in zip(self.fields,data):
parts.append(f.pack(v,self.order))
p = f.pack(v)
if not self.packed:
pad = f.align(offset)-offset
p = b'\0'*pad + p
parts.append(p)
if self.union is False:
return b''.join(parts)
res = b''.join(parts)
if not self.packed:
res = res.ljust(self.size(),b'\0')
return res
else:
return parts[self.union]
def offset_of(self,name):
if self.union is not False:
return 0
o = 0
for f in self.fields:
if f.name==name: return o
if self.union is False:
o += f.size
o = f.align(o)
raise AttributeError(name)

class StructFormatter(StructCore):
Expand Down Expand Up @@ -442,13 +511,13 @@ def define(cls,fmt,offset=-1,atvalue=None,indata=b""):

#------------------------------------------------------------------------------

def StructFactory(name,fmt):
def StructFactory(name,fmt,**kargs):
'Returns a StructFormatter class build with name and format'
return StructDefine(fmt)(type(name,(StructFormatter,),{}))
return StructDefine(fmt,**kargs)(type(name,(StructFormatter,),{}))

def UnionFactory(name,fmt):
def UnionFactory(name,fmt,**kargs):
'Returns a StructFormatter (union) class build with name and format'
return UnionDefine(fmt)(type(name,(StructFormatter,),{}))
return UnionDefine(fmt,**kargs)(type(name,(StructFormatter,),{}))

#------------------------------------------------------------------------------

Expand Down
2 changes: 1 addition & 1 deletion setup.py
View file
Original file line number Diff line number Diff line change
Expand Up @@ -30,7 +30,7 @@

setup(
name = 'amoco',
version = '2.6.1',
version = '2.6.2',
description = 'yet another binary analysis framework',
long_description = long_descr,
# Metadata
Expand Down
Loading

0 comments on commit ba269d3

Please sign in to comment.