mirror of
https://github.com/SickGear/SickGear.git
synced 2024-11-16 09:55:05 +00:00
502 lines
17 KiB
Python
502 lines
17 KiB
Python
"""
|
|
Adobe Portable Document Format (PDF) parser.
|
|
|
|
Author: Christophe Gisquet <christophe.gisquet@free.fr>
|
|
"""
|
|
|
|
from hachoir.parser import Parser
|
|
from hachoir.field import (
|
|
Field, FieldSet,
|
|
ParserError,
|
|
GenericVector,
|
|
UInt8, UInt16, UInt32,
|
|
String,
|
|
RawBytes)
|
|
from hachoir.core.endian import LITTLE_ENDIAN
|
|
from hachoir.core.text_handler import textHandler, hexadecimal
|
|
|
|
MAGIC = b"%PDF-"
|
|
ENDMAGIC = b"%%EOF"
|
|
|
|
|
|
def getLineEnd(s, pos=None):
|
|
if pos is None:
|
|
pos = (s.absolute_address + s.current_size) // 8
|
|
end = s.stream.searchBytesLength(b"\x0D", False, 8 * pos)
|
|
other_end = s.stream.searchBytesLength(b"\x0A", False, 8 * pos)
|
|
if end is None or (other_end is not None and other_end < end):
|
|
return other_end
|
|
return end
|
|
|
|
# TODO: rewrite to account for all possible terminations: ' ', '/', '\0XD'
|
|
# But this probably requires changing *ALL* of the places they are used,
|
|
# as ' ' is swallowed but not the others
|
|
|
|
|
|
def getElementEnd(s, limit=b' ', offset=0):
|
|
addr = s.absolute_address + s.current_size
|
|
addr += 8 * offset
|
|
pos = s.stream.searchBytesLength(limit, True, addr)
|
|
if pos is None:
|
|
# s.info("Can't find '%s' starting at %u" % (limit, addr))
|
|
return None
|
|
return pos
|
|
|
|
|
|
class PDFNumber(Field):
|
|
LIMITS = [b'[', b'/', b'\x0D', b']']
|
|
"""
|
|
sprintf("%i") or sprinf("%.?f")
|
|
"""
|
|
|
|
def __init__(self, parent, name, desc=None):
|
|
Field.__init__(self, parent, name, description=desc)
|
|
# Get size
|
|
size = getElementEnd(parent)
|
|
for limit in self.LIMITS:
|
|
other_size = getElementEnd(parent, limit)
|
|
if other_size is not None:
|
|
other_size -= 1
|
|
if size is None or other_size < size:
|
|
size = other_size
|
|
|
|
self._size = 8 * size
|
|
|
|
# Get value
|
|
val = parent.stream.readBytes(self.absolute_address, size)
|
|
self.info("Number: size=%u value='%s'" % (size, val))
|
|
if val.find(b'.') != -1:
|
|
self.createValue = lambda: float(val)
|
|
else:
|
|
self.createValue = lambda: int(val)
|
|
|
|
|
|
class PDFString(Field):
|
|
"""
|
|
A string of the shape:
|
|
( This string \
|
|
uses 3 lines \
|
|
with the CR(LF) inhibited )
|
|
"""
|
|
|
|
def __init__(self, parent, name, desc=None):
|
|
Field.__init__(self, parent, name, description=desc)
|
|
val = ""
|
|
count = 1
|
|
off = 1
|
|
while not parent.eof:
|
|
char = parent.stream.readBytes(self.absolute_address + 8 * off, 1)
|
|
# Non-ASCII
|
|
if not char.isalpha() or char == '\\':
|
|
off += 1
|
|
continue
|
|
if char == '(':
|
|
count += 1
|
|
if char == ')':
|
|
count -= 1
|
|
# Parenthesis block = 0 => end of string
|
|
if count == 0:
|
|
off += 1
|
|
break
|
|
|
|
# Add it to the string
|
|
val += char
|
|
|
|
self._size = 8 * off
|
|
self.createValue = lambda: val
|
|
|
|
|
|
class PDFName(Field):
|
|
LIMITS = [b'[', b'/', b'<', b']']
|
|
"""
|
|
String starting with '/', where characters may be written using their
|
|
ASCII code (exemple: '#20' would be ' '
|
|
' ', ']' and '\0' are supposed not to be part of the name
|
|
"""
|
|
|
|
def __init__(self, parent, name, desc=None):
|
|
Field.__init__(self, parent, name, description=desc)
|
|
if parent.stream.readBytes(self.absolute_address, 1) != b'/':
|
|
raise ParserError("Unknown PDFName '%s'" %
|
|
parent.stream.readBytes(self.absolute_address, 10))
|
|
size = getElementEnd(parent, offset=1)
|
|
# other_size = getElementEnd(parent, '[')-1
|
|
# if size is None or (other_size is not None and other_size < size):
|
|
# size = other_size
|
|
for limit in self.LIMITS:
|
|
other_size = getElementEnd(parent, limit, 1)
|
|
if other_size is not None:
|
|
other_size -= 1
|
|
if size is None or other_size < size:
|
|
# self.info("New size: %u" % other_size)
|
|
size = other_size
|
|
|
|
self._size = 8 * (size + 1)
|
|
# Value should be without the initial '/' and final ' '
|
|
self.createValue = lambda: parent.stream.readBytes(
|
|
self.absolute_address + 8, size).strip(b' ')
|
|
|
|
|
|
class PDFID(Field):
|
|
"""
|
|
Not described as an object, but let's do as it was.
|
|
This ID has the shape <hexadecimal ASCII string>
|
|
"""
|
|
|
|
def __init__(self, parent, name, desc=None):
|
|
Field.__init__(self, parent, name, description=desc)
|
|
self._size = 8 * getElementEnd(parent, '>')
|
|
self.createValue = lambda: parent.stream.readBytes(
|
|
self.absolute_address + 8, (self._size // 8) - 1)
|
|
|
|
|
|
class NotABool(Exception):
|
|
pass
|
|
|
|
|
|
class PDFBool(Field):
|
|
"""
|
|
"true" or "false" string standing for the boolean value
|
|
"""
|
|
|
|
def __init__(self, parent, name, desc=None):
|
|
Field.__init__(self, parent, name, description=desc)
|
|
if parent.stream.readBytes(self.absolute_address, 4) == b"true":
|
|
self._size = 4
|
|
self.createValue = lambda: True
|
|
elif parent.stream.readBytes(self.absolute_address, 5) == b"false":
|
|
self._size = 5
|
|
self.createValue = lambda: False
|
|
raise NotABool
|
|
|
|
|
|
class LineEnd(FieldSet):
|
|
"""
|
|
Made of 0x0A, 0x0D (we may include several line ends)
|
|
"""
|
|
|
|
def createFields(self):
|
|
while not self.eof:
|
|
addr = self.absolute_address + self.current_size
|
|
char = self.stream.readBytes(addr, 1)
|
|
if char == b'\x0A':
|
|
yield UInt8(self, "lf[]", "Line feed")
|
|
elif char == b'\x0D':
|
|
yield UInt8(self, "cr[]", "Line feed")
|
|
else:
|
|
self.info("Line ends at %u/%u, len %u" %
|
|
(addr, self.stream._size, self.current_size))
|
|
break
|
|
|
|
|
|
class WhiteSpace(String):
|
|
"""
|
|
Made of whitespace characters
|
|
"""
|
|
|
|
def __init__(self, parent, name):
|
|
n = 0
|
|
while 1:
|
|
ch = parent.stream.readBytes(parent.absolute_address + parent.current_size + n * 8, 1)
|
|
if not ch.isspace():
|
|
break
|
|
n += 1
|
|
String.__init__(self, parent, name, n)
|
|
|
|
|
|
class PDFDictionaryPair(FieldSet):
|
|
|
|
def createFields(self):
|
|
yield PDFName(self, "name", getElementEnd(self))
|
|
yield from parsePDFType(self)
|
|
|
|
|
|
class PDFDictionary(FieldSet):
|
|
|
|
def createFields(self):
|
|
yield String(self, "dict_start", 2)
|
|
while not self.eof:
|
|
addr = self.absolute_address + self.current_size
|
|
if self.stream.readBytes(addr, 2) != b'>>':
|
|
yield from parsePDFType(self)
|
|
else:
|
|
break
|
|
yield String(self, "dict_end", 2)
|
|
|
|
|
|
class PDFArray(FieldSet):
|
|
"""
|
|
Array of possibly non-homogeneous elements, starting with '[' and ending
|
|
with ']'
|
|
"""
|
|
|
|
def createFields(self):
|
|
yield String(self, "array_start", 1)
|
|
while self.stream.readBytes(self.absolute_address + self.current_size, 1) != b']':
|
|
yield from parsePDFType(self)
|
|
yield String(self, "array_end", 1)
|
|
|
|
|
|
def parsePDFType(s):
|
|
addr = s.absolute_address + s.current_size
|
|
char = s.stream.readBytes(addr, 1)
|
|
if char == b'/':
|
|
yield PDFName(s, "type[]", getElementEnd(s))
|
|
elif char == b'<':
|
|
if s.stream.readBytes(addr + 8, 1) == b'<':
|
|
yield PDFDictionary(s, "dict[]")
|
|
else:
|
|
yield PDFID(s, "id[]")
|
|
elif char == b'(':
|
|
yield PDFString(s, "string[]")
|
|
elif char == b'[':
|
|
yield PDFArray(s, "array[]")
|
|
else:
|
|
# First parse size
|
|
size = getElementEnd(s)
|
|
for limit in ['/', '>', '<']:
|
|
other_size = getElementEnd(s, limit)
|
|
if other_size is not None:
|
|
other_size -= 1
|
|
if size is None or (other_size > 0 and other_size < size):
|
|
size = other_size
|
|
|
|
# Get element
|
|
name = s.stream.readBytes(addr, size)
|
|
char = s.stream.readBytes(addr + 8 * size + 8, 1)
|
|
if name.count(b' ') > 1 and char == b'<':
|
|
# Probably a catalog
|
|
yield Catalog(s, "catalog[]")
|
|
elif name[:1] in (b'.', b'-', b'+', b'0', b'1', b'2', b'3',
|
|
b'4', b'5', b'6', b'7', b'8', b'9'):
|
|
s.info("Not a catalog: %u spaces and end='%s'" %
|
|
(name.count(b' '), char))
|
|
yield PDFNumber(s, "integer[]")
|
|
else:
|
|
s.info("Trying to parse '%s': %u bytes" %
|
|
(s.stream.readBytes(s.absolute_address + s.current_size, 4), size))
|
|
yield String(s, "unknown[]", size)
|
|
|
|
|
|
class Header(FieldSet):
|
|
|
|
def createFields(self):
|
|
yield String(self, "marker", 5, MAGIC)
|
|
length = getLineEnd(self, 4)
|
|
if length is not None:
|
|
# self.info("Found at position %08X" % len)
|
|
yield String(self, "version", length - 1)
|
|
yield LineEnd(self, "line_end")
|
|
else:
|
|
self.warning("Can't determine version!")
|
|
|
|
def createDescription(self):
|
|
return "PDF version %s" % self["version"].display
|
|
|
|
|
|
class Body(FieldSet):
|
|
|
|
def __init__(self, parent, name, desc=None):
|
|
FieldSet.__init__(self, parent, name, desc)
|
|
pos = self.stream.searchBytesLength(CrossReferenceTable.MAGIC, False)
|
|
if pos is None:
|
|
raise ParserError("Can't find xref starting at %u" %
|
|
(self.absolute_address // 8))
|
|
self._size = 8 * pos - self.absolute_address
|
|
|
|
def createFields(self):
|
|
while self.stream.readBytes(self.absolute_address + self.current_size, 1) == b'%':
|
|
size = getLineEnd(self, 4)
|
|
if size == 2:
|
|
yield String(self, "crc32_comment", 1)
|
|
yield textHandler(UInt16(self, "crc32"), hexadecimal)
|
|
elif size == 4:
|
|
yield String(self, "crc32_comment", 1)
|
|
yield textHandler(UInt32(self, "crc32"), hexadecimal)
|
|
elif self.stream.readBytes(self.absolute_address + self.current_size, size).isalpha():
|
|
yield String(self, "comment[]", size)
|
|
else:
|
|
RawBytes(self, "unknown_data[]", size)
|
|
yield LineEnd(self, "line_end[]")
|
|
|
|
# abs_offset = self.current_size//8
|
|
# TODO: yield objects that read offsets and deduce size from
|
|
# "/cross_ref_table/sub_section[]/entries/item[]"
|
|
offsets = []
|
|
for subsection in self.array("/cross_ref_table/sub_section"):
|
|
for obj in subsection.array("entries/item"):
|
|
if "byte_offset" in obj:
|
|
# Could be inserted already sorted
|
|
offsets.append(obj["byte_offset"].value)
|
|
|
|
offsets.append(self["/cross_ref_table"].absolute_address // 8)
|
|
offsets.sort()
|
|
for index in range(len(offsets) - 1):
|
|
yield Catalog(self, "object[]", size=offsets[index + 1] - offsets[index])
|
|
|
|
|
|
class Entry(FieldSet):
|
|
static_size = 20 * 8
|
|
|
|
def createFields(self):
|
|
typ = self.stream.readBytes(self.absolute_address + 17 * 8, 1)
|
|
if typ == b'n':
|
|
yield PDFNumber(self, "byte_offset")
|
|
elif typ == b'f':
|
|
yield PDFNumber(self, "next_free_object_number")
|
|
else:
|
|
yield PDFNumber(self, "unknown_string")
|
|
yield PDFNumber(self, "generation_number")
|
|
yield UInt8(self, "type")
|
|
yield LineEnd(self, "line_end")
|
|
|
|
def createDescription(self):
|
|
if self["type"].value == 'n':
|
|
return "In-use entry at offset %u" % int(self["byte_offset"].value)
|
|
elif self["type"].value == 'f':
|
|
return "Free entry before in-use object %u" % \
|
|
int(self["next_free_object_number"].value)
|
|
else:
|
|
return "unknown %s" % self["unknown_string"].value
|
|
|
|
|
|
class SubSection(FieldSet):
|
|
|
|
def __init__(self, parent, name, desc=None):
|
|
FieldSet.__init__(self, parent, name, desc)
|
|
self.info("Got entry count: '%s'" % self["entry_count"].value)
|
|
self._size = self.current_size + 8 * 20 * int(self["entry_count"].value) \
|
|
+ self["line_end"].size
|
|
|
|
def createFields(self):
|
|
yield PDFNumber(self, "start_number",
|
|
"Object number of first entry in subsection")
|
|
self.info("start_number = %i" % self["start_number"].value)
|
|
|
|
yield PDFNumber(self, "entry_count", "Number of entries in subsection")
|
|
self.info("entry_count = %i" % self["entry_count"].value)
|
|
yield LineEnd(self, "line_end")
|
|
yield GenericVector(self, "entries", int(self["entry_count"].value),
|
|
Entry)
|
|
# yield LineEnd(self, "line_end[]")
|
|
|
|
def createDescription(self):
|
|
return "Subsection with %s elements, starting at %s" % \
|
|
(self["entry_count"].value, self["start_number"])
|
|
|
|
|
|
class CrossReferenceTable(FieldSet):
|
|
MAGIC = b"xref"
|
|
|
|
def __init__(self, parent, name, desc=None):
|
|
FieldSet.__init__(self, parent, name, description=desc)
|
|
pos = self.stream.searchBytesLength(Trailer.MAGIC, False)
|
|
if pos is None:
|
|
raise ParserError("Can't find '%s' starting at %u" %
|
|
(Trailer.MAGIC, self.absolute_address // 8))
|
|
self._size = 8 * pos - self.absolute_address
|
|
|
|
def createFields(self):
|
|
yield RawBytes(self, "marker", len(self.MAGIC))
|
|
yield LineEnd(self, "line_end[]")
|
|
while not self.eof:
|
|
yield SubSection(self, "sub_section[]")
|
|
|
|
|
|
class Catalog(FieldSet):
|
|
END_NAME = [b'<', b'/', b'[']
|
|
|
|
def __init__(self, parent, name, size=None, desc=None):
|
|
FieldSet.__init__(self, parent, name, description=desc)
|
|
if size is not None:
|
|
self._size = 8 * size
|
|
# object catalogs are ended with "obj"
|
|
elif self["object"].value == "obj":
|
|
size = self.stream.searchBytesLength(b"endobj", False)
|
|
if size is not None:
|
|
self._size = 8 * (size + 2)
|
|
|
|
def createFields(self):
|
|
yield PDFNumber(self, "index")
|
|
yield PDFNumber(self, "unknown[]")
|
|
length = getElementEnd(self)
|
|
for limit in self.END_NAME:
|
|
new_length = getElementEnd(self, limit)
|
|
if length is None or (new_length is not None and new_length - len(limit) < length):
|
|
length = new_length - len(limit)
|
|
yield String(self, "object", length, strip=' ')
|
|
if self.stream.readBytes(self.absolute_address + self.current_size, 2) == b'<<':
|
|
yield PDFDictionary(self, "key_list")
|
|
# End of catalog: this one has "endobj"
|
|
if self["object"].value == "obj":
|
|
yield LineEnd(self, "line_end[]")
|
|
yield String(self, "end_object", len("endobj"))
|
|
yield LineEnd(self, "line_end[]")
|
|
|
|
|
|
class Trailer(FieldSet):
|
|
MAGIC = b"trailer"
|
|
|
|
def createFields(self):
|
|
yield RawBytes(self, "marker", len(self.MAGIC))
|
|
yield WhiteSpace(self, "sep[]")
|
|
yield String(self, "start_attribute_marker", 2)
|
|
addr = self.absolute_address + self.current_size
|
|
while self.stream.readBytes(addr, 2) != b'>>':
|
|
yield WhiteSpace(self, "sep[]")
|
|
t = PDFName(self, "type[]")
|
|
yield t
|
|
name = t.value.decode()
|
|
self.info("Parsing PDFName '%s'" % name)
|
|
if name == "Size":
|
|
yield PDFNumber(self, "size", "Entries in the file cross-reference section")
|
|
elif name == "Prev":
|
|
yield PDFNumber(self, "offset")
|
|
elif name == "Root":
|
|
yield Catalog(self, "object_catalog")
|
|
elif name == "Info":
|
|
yield Catalog(self, "info")
|
|
elif name == "ID":
|
|
yield PDFArray(self, "id")
|
|
elif name == "Encrypt":
|
|
yield PDFDictionary(self, "decrypt")
|
|
else:
|
|
raise ParserError("Don't know trailer type '%s'" % name)
|
|
addr = self.absolute_address + self.current_size
|
|
yield String(self, "end_attribute_marker", 2)
|
|
yield LineEnd(self, "line_end[]")
|
|
yield String(self, "start_xref", 9)
|
|
yield LineEnd(self, "line_end[]")
|
|
yield PDFNumber(self, "cross_ref_table_start_address")
|
|
yield LineEnd(self, "line_end[]")
|
|
yield String(self, "end_marker", len(ENDMAGIC))
|
|
yield LineEnd(self, "line_end[]")
|
|
|
|
|
|
class PDFDocument(Parser):
|
|
endian = LITTLE_ENDIAN
|
|
PARSER_TAGS = {
|
|
"id": "pdf",
|
|
"category": "misc",
|
|
"file_ext": ("pdf",),
|
|
"mime": ("application/pdf",),
|
|
"min_size": (5 + 4) * 8,
|
|
"magic": ((MAGIC, 5),),
|
|
"description": "Portable Document Format (PDF) document"
|
|
}
|
|
|
|
def validate(self):
|
|
if self.stream.readBytes(0, len(MAGIC)) != MAGIC:
|
|
return "Invalid magic string"
|
|
return True
|
|
|
|
# Size is not always determined by position of "%%EOF":
|
|
# - updated documents have several of those
|
|
# - PDF files should be parsed from *end*
|
|
# => TODO: find when a document has been updated
|
|
|
|
def createFields(self):
|
|
yield Header(self, "header")
|
|
yield Body(self, "body")
|
|
yield CrossReferenceTable(self, "cross_ref_table")
|
|
yield Trailer(self, "trailer")
|