+def ascii_visualize(ba):
+ """Output only ASCII printable characters, like in hexdump -C
+
+ Example output for given binary string (right part)::
+
+ 92 2b 39 20 65 91 e6 8e 95 93 1a 58 df 02 78 ea |.+9 e......X..x.|
+ ^^^^^^^^^^^^^^^^
+ """
+ return "".join((chr(b) if 0x20 <= b <= 0x7E else ".") for b in ba)
+
+
+def hexdump(raw):
+ """Generate ``hexdump -C`` like output
+
+ Rendered example::
+
+ 00000000 30 80 30 80 a0 80 02 01 02 00 00 02 14 54 a5 18 |0.0..........T..|
+ 00000010 69 ef 8b 3f 15 fd ea ad bd 47 e0 94 81 6b 06 6a |i..?.....G...k.j|
+
+ Result of that function is a generator of lines, where each line is
+ a list of columns::
+
+ [
+ [...],
+ ["00000010 ", " 69", " ef", " 8b", " 3f", " 15", " fd", " ea", " ad ",
+ " bd", " 47", " e0", " 94", " 81", " 6b", " 06", " 6a ",
+ " |i..?.....G...k.j|"]
+ [...],
+ ]
+ """
+ hexed = hexenc(raw).upper()
+ addr, cols = 0, ["%08x " % 0]
+ for i in range(0, len(hexed), 2):
+ if i != 0 and i // 2 % 8 == 0:
+ cols[-1] += " "
+ if i != 0 and i // 2 % 16 == 0:
+ cols.append(" |%s|" % ascii_visualize(bytes(raw[addr:addr + 16])))
+ yield cols
+ addr += 16
+ cols = ["%08x " % addr]
+ cols.append(" " + hexed[i:i + 2])
+ if len(cols) > 0:
+ cols.append(" |%s|" % ascii_visualize(bytes(raw[addr:])))
+ yield cols
+
+
+def browse(raw, obj, oid_maps=()):
+ """Interactive browser
+
+ :param bytes raw: binary data you decoded
+ :param obj: decoded :py:class:`pyderasn.Obj`
+ :param oid_maps: list of ``str(OID) <-> human readable string`` dictionaries.
+ Its human readable form is printed when OID is met
+
+ .. note:: `urwid <http://urwid.org/>`__ dependency required
+
+ This browser is an interactive terminal application for browsing
+ structures of your decoded ASN.1 objects. You can quit it with **q**
+ key. It consists of three windows:
+
+ :tree:
+ View of ASN.1 elements hierarchy. You can navigate it using **Up**,
+ **Down**, **PageUp**, **PageDown**, **Home**, **End** keys.
+ **Left** key goes to constructed element above. **Plus**/**Minus**
+ keys collapse/uncollapse constructed elements. **Space** toggles it
+ :info:
+ window with various information about element. You can scroll it
+ with **h**/**l** (down, up) (**H**/**L** for triple speed) keys
+ :hexdump:
+ window with raw data hexdump and highlighted current element's
+ contents. It automatically focuses on element's data. You can
+ scroll it with **j**/**k** (down, up) (**J**/**K** for triple
+ speed) keys. If element has explicit tag, then it also will be
+ highlighted with different colour
+
+ Window's header contains current decode path and progress bars with
+ position in *info* and *hexdump* windows.
+
+ If you press **d**, then current element will be saved in the
+ current directory under its decode path name (adding ".0", ".1", etc
+ suffix if such file already exists). **D** will save it with explicit tag.
+
+ You can also invoke it with ``--browse`` command line argument.
+ """
+ from copy import deepcopy
+ from os.path import exists as path_exists
+ import urwid
+
+ class TW(urwid.TreeWidget):
+ def __init__(self, state, *args, **kwargs):
+ self.state = state
+ self.scrolled = {"info": False, "hexdump": False}
+ super().__init__(*args, **kwargs)
+
+ def _get_pp(self):
+ pp = self.get_node().get_value()
+ constructed = len(pp) > 1
+ return (pp if hasattr(pp, "_fields") else pp[0]), constructed
+
+ def _state_update(self):
+ pp, _ = self._get_pp()
+ self.state["decode_path"].set_text(
+ ":".join(str(p) for p in pp.decode_path)
+ )
+ lines = deepcopy(self.state["hexed"])
+
+ def attr_set(i, attr):
+ line = lines[i // 16]
+ idx = 1 + (i - 16 * (i // 16))
+ line[idx] = (attr, line[idx])
+
+ if pp.expl_offset is not None:
+ for i in range(
+ pp.expl_offset,
+ pp.expl_offset + pp.expl_tlen + pp.expl_llen,
+ ):
+ attr_set(i, "select-expl")
+ for i in range(pp.offset, pp.offset + pp.tlen + pp.llen + pp.vlen):
+ attr_set(i, "select-value")
+ self.state["hexdump"]._set_body([urwid.Text(line) for line in lines])
+ self.state["hexdump"].set_focus(pp.offset // 16)
+ self.state["hexdump"].set_focus_valign("middle")
+ self.state["hexdump_bar"].set_completion(
+ (100 * pp.offset // 16) //
+ len(self.state["hexdump"]._body.positions())
+ )
+
+ lines = [
+ [("header", "Name: "), pp.obj_name],
+ [("header", "Type: "), pp.asn1_type_name],
+ [("header", "Offset: "), "%d (0x%x)" % (pp.offset, pp.offset)],
+ [("header", "[TLV]len: "), "%d/%d/%d" % (
+ pp.tlen, pp.llen, pp.vlen,
+ )],
+ [("header", "TLVlen: "), "%d" % sum((
+ pp.tlen, pp.llen, pp.vlen,
+ ))],
+ [("header", "Slice: "), "[%d:%d]" % (
+ pp.offset, pp.offset + pp.tlen + pp.llen + pp.vlen,
+ )],
+ ]
+ if pp.lenindef:
+ lines.append([("warning", "LENINDEF")])
+ if pp.ber_encoded:
+ lines.append([("warning", "BER encoded")])
+ if pp.bered:
+ lines.append([("warning", "BERed")])
+ if pp.expl is not None:
+ lines.append([("header", "EXPLICIT")])
+ klass, _, num = pp.expl
+ lines.append([" Tag: %s%d" % (TagClassReprs[klass], num)])
+ if pp.expl_offset is not None:
+ lines.append([" Offset: %d" % pp.expl_offset])
+ lines.append([" [TLV]len: %d/%d/%d" % (
+ pp.expl_tlen, pp.expl_llen, pp.expl_vlen,
+ )])
+ lines.append([" TLVlen: %d" % sum((
+ pp.expl_tlen, pp.expl_llen, pp.expl_vlen,
+ ))])
+ lines.append([" Slice: [%d:%d]" % (
+ pp.expl_offset,
+ pp.expl_offset + pp.expl_tlen + pp.expl_llen + pp.expl_vlen,
+ )])
+ if pp.impl is not None:
+ klass, _, num = pp.impl
+ lines.append([
+ ("header", "IMPLICIT: "), "%s%d" % (TagClassReprs[klass], num),
+ ])
+ if pp.optional:
+ lines.append(["OPTIONAL"])
+ if pp.default:
+ lines.append(["DEFAULT"])
+ if len(pp.decode_path) > 0:
+ ent = pp.decode_path[-1]
+ if isinstance(ent, DecodePathDefBy):
+ lines.append([""])
+ value = str(ent.defined_by)
+ oid_name = find_oid_name(
+ ent.defined_by.asn1_type_name, oid_maps, value,
+ )
+ lines.append([("header", "DEFINED BY: "), "%s" % (
+ value if oid_name is None
+ else "%s (%s)" % (oid_name, value)
+ )])
+ lines.append([""])
+ if pp.value is not None:
+ lines.append([("header", "Value: "), pp.value])
+ if (
+ len(oid_maps) > 0 and
+ pp.asn1_type_name == ObjectIdentifier.asn1_type_name
+ ):
+ for oid_map in oid_maps:
+ oid_name = oid_map.get(pp.value)
+ if oid_name is not None:
+ lines.append([("header", "Human: "), oid_name])
+ break
+ if pp.asn1_type_name == Integer.asn1_type_name:
+ lines.append([
+ ("header", "Decimal: "), "%d" % int(pp.obj),
+ ])
+ lines.append([
+ ("header", "Hexadecimal: "), colonize_hex(pp.obj.tohex()),
+ ])
+ if pp.blob.__class__ == bytes:
+ blob = hexenc(pp.blob).upper()
+ for i in range(0, len(blob), 32):
+ lines.append([colonize_hex(blob[i:i + 32])])
+ elif pp.blob.__class__ == tuple:
+ lines.append([", ".join(pp.blob)])
+ self.state["info"]._set_body([urwid.Text(line) for line in lines])
+ self.state["info_bar"].set_completion(0)
+
+ def selectable(self):
+ if self.state["widget_current"] != self:
+ self.state["widget_current"] = self
+ self.scrolled["info"] = False
+ self.scrolled["hexdump"] = False
+ self._state_update()
+ return super().selectable()
+
+ def _get_display_text_without_offset(self):
+ pp, constructed = self._get_pp()
+ style = "constructed" if constructed else ""
+ if len(pp.decode_path) == 0:
+ return (style, pp.obj_name)
+ if pp.asn1_type_name == "EOC":
+ return ("eoc", "EOC")
+ ent = pp.decode_path[-1]
+ if isinstance(ent, DecodePathDefBy):
+ value = str(ent.defined_by)
+ oid_name = find_oid_name(
+ ent.defined_by.asn1_type_name, oid_maps, value,
+ )
+ return ("defby", "DEFBY:" + (
+ value if oid_name is None else oid_name
+ ))
+ return (style, ent)
+
+ def get_display_text(self):
+ pp, _ = self._get_pp()
+ style, ent = self._get_display_text_without_offset()
+ return [(style, ent), " [%d]" % pp.offset]
+
+ def _scroll(self, what, step):
+ self.state[what]._invalidate()
+ pos = self.state[what].focus_position
+ if not self.scrolled[what]:
+ self.scrolled[what] = True
+ pos -= 2
+ pos = max(0, pos + step)
+ pos = min(pos, len(self.state[what]._body.positions()) - 1)
+ self.state[what].set_focus(pos)
+ self.state[what].set_focus_valign("top")
+ self.state[what + "_bar"].set_completion(
+ (100 * pos) // len(self.state[what]._body.positions())
+ )
+
+ def keypress(self, size, key):
+ if key == "q":
+ raise urwid.ExitMainLoop()
+
+ if key == " ":
+ self.expanded = not self.expanded
+ self.update_expanded_icon()
+ return None
+
+ hexdump_steps = {"j": 1, "k": -1, "J": 5, "K": -5}
+ if key in hexdump_steps:
+ self._scroll("hexdump", hexdump_steps[key])
+ return None
+
+ info_steps = {"h": 1, "l": -1, "H": 5, "L": -5}
+ if key in info_steps:
+ self._scroll("info", info_steps[key])
+ return None
+
+ if key in ("d", "D"):
+ pp, _ = self._get_pp()
+ dp = ":".join(str(p) for p in pp.decode_path)
+ dp = dp.replace(" ", "_")
+ if dp == "":
+ dp = "root"
+ if key == "d" or pp.expl_offset is None:
+ data = self.state["raw"][pp.offset:(
+ pp.offset + pp.tlen + pp.llen + pp.vlen
+ )]
+ else:
+ data = self.state["raw"][pp.expl_offset:(
+ pp.expl_offset + pp.expl_tlen + pp.expl_llen + pp.expl_vlen
+ )]
+ ctr = 0
+
+ def duplicate_path(dp, ctr):
+ if ctr == 0:
+ return dp
+ return "%s.%d" % (dp, ctr)
+
+ while True:
+ if not path_exists(duplicate_path(dp, ctr)):
+ break
+ ctr += 1
+ dp = duplicate_path(dp, ctr)
+ with open(dp, "wb") as fd:
+ fd.write(data)
+ self.state["decode_path"].set_text(
+ ("warning", "Saved to: " + dp)
+ )
+ return None
+ return super().keypress(size, key)
+
+ class PN(urwid.ParentNode):
+ def __init__(self, state, value, *args, **kwargs):
+ self.state = state
+ if not hasattr(value, "_fields"):
+ value = list(value)
+ super().__init__(value, *args, **kwargs)
+
+ def load_widget(self):
+ return TW(self.state, self)
+
+ def load_child_keys(self):
+ value = self.get_value()
+ if hasattr(value, "_fields"):
+ return []
+ return range(len(value[1:]))
+
+ def load_child_node(self, key):
+ return PN(
+ self.state,
+ self.get_value()[key + 1],
+ parent=self,
+ key=key,
+ depth=self.get_depth() + 1,
+ )
+
+ class LabeledPG(urwid.ProgressBar):
+ def __init__(self, label, *args, **kwargs):
+ self.label = label
+ super().__init__(*args, **kwargs)
+
+ def get_text(self):
+ return "%s: %s" % (self.label, super().get_text())
+
+ WinHexdump = urwid.ListBox([urwid.Text("")])
+ WinInfo = urwid.ListBox([urwid.Text("")])
+ WinDecodePath = urwid.Text("", "center")
+ WinInfoBar = LabeledPG("info", "pg-normal", "pg-complete")
+ WinHexdumpBar = LabeledPG("hexdump", "pg-normal", "pg-complete")
+ WinTree = urwid.TreeListBox(urwid.TreeWalker(PN(
+ {
+ "raw": raw,
+ "hexed": list(hexdump(raw)),
+ "widget_current": None,
+ "info": WinInfo,
+ "info_bar": WinInfoBar,
+ "hexdump": WinHexdump,
+ "hexdump_bar": WinHexdumpBar,
+ "decode_path": WinDecodePath,
+ },
+ list(obj.pps()),
+ )))
+ help_text = " ".join((
+ "q:quit",
+ "space:(un)collapse",
+ "(pg)up/down/home/end:nav",
+ "jkJK:hexdump hlHL:info",
+ "dD:dump",
+ ))
+ urwid.MainLoop(
+ urwid.Frame(
+ urwid.Columns([
+ ("weight", 1, WinTree),
+ ("weight", 2, urwid.Pile([
+ urwid.LineBox(WinInfo),
+ urwid.LineBox(WinHexdump),
+ ])),
+ ]),
+ header=urwid.Columns([
+ ("weight", 2, urwid.AttrWrap(WinDecodePath, "header")),
+ ("weight", 1, WinInfoBar),
+ ("weight", 1, WinHexdumpBar),
+ ]),
+ footer=urwid.AttrWrap(urwid.Text(help_text), "help")
+ ),
+ [
+ ("header", "bold", ""),
+ ("constructed", "bold", ""),
+ ("help", "light magenta", ""),
+ ("warning", "light red", ""),
+ ("defby", "light red", ""),
+ ("eoc", "dark red", ""),
+ ("select-value", "light green", ""),
+ ("select-expl", "light red", ""),
+ ("pg-normal", "", "light blue"),
+ ("pg-complete", "black", "yellow"),
+ ],
+ ).run()
+
+