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Implement QPDFObjectHandle::parse 

Move object parsing code from QPDF to QPDFObjectHandle and
parameterize the parts of it that are specific to a QPDF object.
Provide a version that can't handle indirect objects and that can be
called on an arbitrary string.

A side effect of this change is that the offset used when reporting
invalid stream length has changed, but since the new value seems like
a better value than the old one, the test suite has been updated
rather than making the code backward compatible.  This only effects
the offset reported for invalid streams that lack /Length or have an
invalid /Length key.

Updated some test code and exmaples to use QPDFObjectHandle::parse.

Supporting changes include adding a BufferInputSource constructor that
takes a string.
This commit is contained in:
Jay Berkenbilt 2012-07-21 09:00:06 -04:00
parent f3e267fce2
commit 6bbea4baa0
18 changed files with 628 additions and 396 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

10
ChangeLog
View File

@ -1,3 +1,13 @@
2012-07-21 Jay Berkenbilt <ejb@ql.org>
* Add new method QPDFObjectHandle::replaceDict to replace a
stream's dictionary. Use with caution; see comments in
QPDFObjectHandle.hh.
* Add new method QPDFObjectHandle::parse for creation of
QPDFObjectHandle objects from string representations of the
objects. Thanks to Tobias Hoffmann for the idea.
2012-07-15 Jay Berkenbilt <ejb@ql.org>
* add new QPDF::isEncrypted method that returns some additional

6
TODO
View File

@ -20,16 +20,14 @@ Next
* Make sure that the release notes call attention to the one API
breaking change: removal of length from replaceStreamData.
* Add a way to create new QPDFObjectHandles with a string
representation of them, such as
QPDFObjectHandle::parse("<< /a 1 /b 2 >>");
* Document thread safety: One individual QPDF or QPDFWriter object
can only be used by one thread at a time, but multiple threads can
simultaneously use separate objects.
* Write some documentation about the design of copyForeignObject.
* Mention QPDFObjectHandle::parse in the documentation.
* copyForeignObject still to do:
- qpdf command

36
examples/pdf-create.cc
View File

@ -81,24 +81,28 @@ static void create_pdf(char const* filename)
// Add an indirect object to contain a font descriptor for the
// built-in Helvetica font.
QPDFObjectHandle font = pdf.makeIndirectObject(
QPDFObjectHandle::newDictionary());
font.replaceKey("/Type", newName("/Font"));
font.replaceKey("/Subtype", newName("/Type1"));
font.replaceKey("/Name", newName("/F1"));
font.replaceKey("/BaseFont", newName("/Helvetica"));
font.replaceKey("/Encoding", newName("/WinAnsiEncoding"));
QPDFObjectHandle::parse(
"<<"
" /Type /Font"
" /Subtype /Type1"
" /Name /F1"
" /BaseFont /Helvetica"
" /Encoding /WinAnsiEncoding"
">>"));
// Create a stream to encode our image. We don't have to set the
// length or filters. QPDFWriter will fill in the length and
// compress the stream data using FlateDecode by default.
QPDFObjectHandle image = QPDFObjectHandle::newStream(&pdf);
QPDFObjectHandle image_dict = image.getDict();
image_dict.replaceKey("/Type", newName("/XObject"));
image_dict.replaceKey("/Subtype", newName("/Image"));
image_dict.replaceKey("/ColorSpace", newName("/DeviceRGB"));
image_dict.replaceKey("/BitsPerComponent", newInteger(8));
image_dict.replaceKey("/Width", newInteger(100));
image_dict.replaceKey("/Height", newInteger(100));
image.replaceDict(QPDFObjectHandle::parse(
"<<"
" /Type /XObject"
" /Subtype /Image"
" /ColorSpace /DeviceRGB"
" /BitsPerComponent 8"
" /Width 100"
" /Height 100"
">>"));
// Provide the stream data.
ImageProvider* p = new ImageProvider(100, 100);
PointerHolder<QPDFObjectHandle::StreamDataProvider> provider(p);
@ -107,10 +111,8 @@ static void create_pdf(char const* filename)
QPDFObjectHandle::newNull());
// Create direct objects as needed by the page dictionary.
QPDFObjectHandle procset = QPDFObjectHandle::newArray();
procset.appendItem(newName("/PDF"));
procset.appendItem(newName("/Text"));
procset.appendItem(newName("/ImageC"));
QPDFObjectHandle procset = QPDFObjectHandle::parse(
"[/PDF /Text /ImageC]");
QPDFObjectHandle rfont = QPDFObjectHandle::newDictionary();
rfont.replaceKey("/F1", font);

2
include/qpdf/BufferInputSource.hh
View File

@ -9,6 +9,8 @@ class BufferInputSource: public InputSource
public:
BufferInputSource(std::string const& description, Buffer* buf,
bool own_memory = false);
BufferInputSource(std::string const& description,
std::string const& contents);
virtual ~BufferInputSource();
virtual qpdf_offset_t findAndSkipNextEOL();
virtual std::string const& getName() const;

21
include/qpdf/QPDF.hh
View File

@ -531,6 +531,23 @@ class QPDF
std::map<ObjGen, QPDFObjectHandle> foreign_streams;
};
class StringDecrypter: public QPDFObjectHandle::StringDecrypter
{
friend class QPDF;
public:
StringDecrypter(QPDF* qpdf, int objid, int gen);
virtual ~StringDecrypter()
{
}
virtual void decryptString(std::string& val);
private:
QPDF* qpdf;
int objid;
int gen;
};
void parse(char const* password);
void warn(QPDFExc const& e);
void setTrailer(QPDFObjectHandle obj);
@ -547,10 +564,6 @@ class QPDF
QPDFObjectHandle readObject(
PointerHolder<InputSource>, std::string const& description,
int objid, int generation, bool in_object_stream);
QPDFObjectHandle readObjectInternal(
PointerHolder<InputSource> input, int objid, int generation,
bool in_object_stream,
bool in_array, bool in_dictionary);
size_t recoverStreamLength(
PointerHolder<InputSource> input, int objid, int generation,
qpdf_offset_t stream_offset);

56
include/qpdf/QPDFObjectHandle.hh
View File

@ -18,6 +18,7 @@
#include <qpdf/PointerHolder.hh>
#include <qpdf/Buffer.hh>
#include <qpdf/InputSource.hh>
#include <qpdf/QPDFObject.hh>
@ -25,6 +26,7 @@ class Pipeline;
class QPDF;
class QPDF_Dictionary;
class QPDF_Array;
class QPDFTokenizer;
class QPDFObjectHandle
{
@ -57,6 +59,18 @@ class QPDFObjectHandle
Pipeline* pipeline) = 0;
};
// This class is used by parse to decrypt strings when reading an
// object that contains encrypted strings.
class StringDecrypter
{
public:
QPDF_DLL
virtual ~StringDecrypter()
{
}
virtual void decryptString(std::string& val) = 0;
};
QPDF_DLL
QPDFObjectHandle();
QPDF_DLL
@ -95,6 +109,30 @@ class QPDFObjectHandle
// Public factory methods
// Construct an object of any type from a string representation of
// the object. Throws QPDFExc with an empty filename and an
// offset into the string if there is an error. Any indirect
// object syntax (obj gen R) will cause a logic_error exception to
// be thrown. If object_description is provided, it will appear
// in the message of any QPDFExc exception thrown for invalid
// syntax.
QPDF_DLL
static QPDFObjectHandle parse(std::string const& object_str,
std::string const& object_description = "");
// Construct an object as above by reading from the given
// InputSource at its current position and using the tokenizer you
// supply. Indirect objects and encrypted strings are permitted.
// This method is intended to be called by QPDF for parsing
// objects that are ready from the object's input stream.
QPDF_DLL
static QPDFObjectHandle parse(PointerHolder<InputSource> input,
std::string const& object_description,
QPDFTokenizer&, bool& empty,
StringDecrypter* decrypter,
QPDF* context);
// Type-specific factories
QPDF_DLL
static QPDFObjectHandle newNull();
QPDF_DLL
@ -124,7 +162,8 @@ class QPDFObjectHandle
// object. A subsequent call must be made to replaceStreamData()
// to provide data for the stream. The stream's dictionary may be
// retrieved by calling getDict(), and the resulting dictionary
// may be modified.
// may be modified. Alternatively, you can create a new
// dictionary and call replaceDict to install it.
QPDF_DLL
static QPDFObjectHandle newStream(QPDF* qpdf);
@ -303,6 +342,15 @@ class QPDFObjectHandle
bool pipeStreamData(Pipeline*, bool filter,
bool normalize, bool compress);
// Replace a stream's dictionary. The new dictionary must be
// consistent with the stream's data. This is most appropriately
// used when creating streams from scratch that will use a stream
// data provider and therefore start with an empty dictionary. It
// may be more convenient in this case than calling getDict and
// modifying it for each key. The pdf-create example does this.
QPDF_DLL
void replaceDict(QPDFObjectHandle);
// Replace this stream's stream data with the given data buffer,
// and replace the /Filter and /DecodeParms keys in the stream
// dictionary with the given values. (If either value is empty,
@ -489,6 +537,12 @@ class QPDFObjectHandle
void dereference();
void makeDirectInternal(std::set<int>& visited);
void releaseResolved();
static QPDFObjectHandle parseInternal(
PointerHolder<InputSource> input,
std::string const& object_description,
QPDFTokenizer& tokenizer, bool& empty,
StringDecrypter* decrypter, QPDF* context,
bool in_array, bool in_dictionary);
bool initialized;

12
libqpdf/BufferInputSource.cc
View File

@ -11,6 +11,18 @@ BufferInputSource::BufferInputSource(std::string const& description,
{
}
BufferInputSource::BufferInputSource(std::string const& description,
std::string const& contents) :
own_memory(true),
description(description),
buf(0),
cur_offset(0)
{
this->buf = new Buffer(contents.length());
unsigned char* bp = buf->getBuffer();
memcpy(bp, (char*)contents.c_str(), contents.length());
}
BufferInputSource::~BufferInputSource()
{
if (own_memory)

516
libqpdf/QPDF.cc
View File

@ -68,6 +68,18 @@ QPDF::CopiedStreamDataProvider::registerForeignStream(
this->foreign_streams[local_og] = foreign_stream;
}
QPDF::StringDecrypter::StringDecrypter(QPDF* qpdf, int objid, int gen) :
qpdf(qpdf),
objid(objid),
gen(gen)
{
}
void
QPDF::StringDecrypter::decryptString(std::string& val)
{
qpdf->decryptString(val, objid, gen);
}
std::string const&
QPDF::QPDFVersion()
@ -940,361 +952,167 @@ QPDF::readObject(PointerHolder<InputSource> input,
{
setLastObjectDescription(description, objid, generation);
qpdf_offset_t offset = input->tell();
QPDFObjectHandle object = readObjectInternal(
input, objid, generation, in_object_stream, false, false);
bool empty = false;
PointerHolder<StringDecrypter> decrypter_ph;
StringDecrypter* decrypter = 0;
if (this->encrypted && (! in_object_stream))
{
decrypter_ph = new StringDecrypter(this, objid, generation);
decrypter = decrypter_ph.getPointer();
}
QPDFObjectHandle object = QPDFObjectHandle::parse(
input, description, this->tokenizer, empty, decrypter, this);
if (empty)
{
// Nothing in the PDF spec appears to allow empty objects, but
// they have been encountered in actual PDF files and Adobe
// Reader appears to ignore them.
warn(QPDFExc(qpdf_e_damaged_pdf, input->getName(),
this->last_object_description,
input->getLastOffset(),
"empty object treated as null"));
}
else if (object.isDictionary() && (! in_object_stream))
{
// check for stream
qpdf_offset_t cur_offset = input->tell();
if (readToken(input) ==
QPDFTokenizer::Token(QPDFTokenizer::tt_word, "stream"))
{
// The PDF specification states that the word "stream"
// should be followed by either a carriage return and
// a newline or by a newline alone. It specifically
// disallowed following it by a carriage return alone
// since, in that case, there would be no way to tell
// whether the NL in a CR NL sequence was part of the
// stream data. However, some readers, including
// Adobe reader, accept a carriage return by itself
// when followed by a non-newline character, so that's
// what we do here.
{
char ch;
if (input->read(&ch, 1) == 0)
{
// A premature EOF here will result in some
// other problem that will get reported at
// another time.
}
else if (ch == '\n')
{
// ready to read stream data
QTC::TC("qpdf", "QPDF stream with NL only");
}
else if (ch == '\r')
{
// Read another character
if (input->read(&ch, 1) != 0)
{
if (ch == '\n')
{
// Ready to read stream data
QTC::TC("qpdf", "QPDF stream with CRNL");
}
else
{
// Treat the \r by itself as the
// whitespace after endstream and
// start reading stream data in spite
// of not having seen a newline.
QTC::TC("qpdf", "QPDF stream with CR only");
input->unreadCh(ch);
warn(QPDFExc(
qpdf_e_damaged_pdf,
input->getName(),
this->last_object_description,
input->tell(),
"stream keyword followed"
" by carriage return only"));
}
}
}
else
{
QTC::TC("qpdf", "QPDF stream without newline");
warn(QPDFExc(qpdf_e_damaged_pdf, input->getName(),
this->last_object_description,
input->tell(),
"stream keyword not followed"
" by proper line terminator"));
}
}
// Must get offset before accessing any additional
// objects since resolving a previously unresolved
// indirect object will change file position.
qpdf_offset_t stream_offset = input->tell();
size_t length = 0;
try
{
std::map<std::string, QPDFObjectHandle> dict =
object.getDictAsMap();
if (dict.count("/Length") == 0)
{
QTC::TC("qpdf", "QPDF stream without length");
throw QPDFExc(qpdf_e_damaged_pdf, input->getName(),
this->last_object_description, offset,
"stream dictionary lacks /Length key");
}
QPDFObjectHandle length_obj = dict["/Length"];
if (! length_obj.isInteger())
{
QTC::TC("qpdf", "QPDF stream length not integer");
throw QPDFExc(qpdf_e_damaged_pdf, input->getName(),
this->last_object_description, offset,
"/Length key in stream dictionary is not "
"an integer");
}
length = length_obj.getIntValue();
input->seek(
stream_offset + (qpdf_offset_t)length, SEEK_SET);
if (! (readToken(input) ==
QPDFTokenizer::Token(
QPDFTokenizer::tt_word, "endstream")))
{
QTC::TC("qpdf", "QPDF missing endstream");
throw QPDFExc(qpdf_e_damaged_pdf, input->getName(),
this->last_object_description,
input->getLastOffset(),
"expected endstream");
}
}
catch (QPDFExc& e)
{
if (this->attempt_recovery)
{
// may throw an exception
length = recoverStreamLength(
input, objid, generation, stream_offset);
}
else
{
throw e;
}
}
object = QPDFObjectHandle::Factory::newStream(
this, objid, generation, object, stream_offset, length);
}
else
{
input->seek(cur_offset, SEEK_SET);
}
}
// Override last_offset so that it points to the beginning of the
// object we just read
input->setLastOffset(offset);
return object;
}
QPDFObjectHandle
QPDF::readObjectInternal(PointerHolder<InputSource> input,
int objid, int generation,
bool in_object_stream,
bool in_array, bool in_dictionary)
{
if (in_dictionary && in_array)
{
// Although dictionaries and arrays arbitrarily nest, these
// variables indicate what is at the top of the stack right
// now, so they can, by definition, never both be true.
throw std::logic_error(
"INTERNAL ERROR: readObjectInternal: in_dict && in_array");
}
QPDFObjectHandle object;
qpdf_offset_t offset = input->tell();
std::vector<QPDFObjectHandle> olist;
bool done = false;
while (! done)
{
object = QPDFObjectHandle();
QPDFTokenizer::Token token = readToken(input);
switch (token.getType())
{
case QPDFTokenizer::tt_brace_open:
case QPDFTokenizer::tt_brace_close:
// Don't know what to do with these for now
QTC::TC("qpdf", "QPDF bad brace");
throw QPDFExc(qpdf_e_damaged_pdf, input->getName(),
this->last_object_description,
input->getLastOffset(),
"unexpected brace token");
break;
case QPDFTokenizer::tt_array_close:
if (in_array)
{
done = true;
}
else
{
QTC::TC("qpdf", "QPDF bad array close");
throw QPDFExc(qpdf_e_damaged_pdf, input->getName(),
this->last_object_description,
input->getLastOffset(),
"unexpected array close token");
}
break;
case QPDFTokenizer::tt_dict_close:
if (in_dictionary)
{
done = true;
}
else
{
QTC::TC("qpdf", "QPDF bad dictionary close");
throw QPDFExc(qpdf_e_damaged_pdf, input->getName(),
this->last_object_description,
input->getLastOffset(),
"unexpected dictionary close token");
}
break;
case QPDFTokenizer::tt_array_open:
object = readObjectInternal(
input, objid, generation, in_object_stream, true, false);
break;
case QPDFTokenizer::tt_dict_open:
object = readObjectInternal(
input, objid, generation, in_object_stream, false, true);
break;
case QPDFTokenizer::tt_bool:
object = QPDFObjectHandle::newBool(
(token.getValue() == "true"));
break;
case QPDFTokenizer::tt_null:
object = QPDFObjectHandle::newNull();
break;
case QPDFTokenizer::tt_integer:
object = QPDFObjectHandle::newInteger(
QUtil::string_to_ll(token.getValue().c_str()));
break;
case QPDFTokenizer::tt_real:
object = QPDFObjectHandle::newReal(token.getValue());
break;
case QPDFTokenizer::tt_name:
object = QPDFObjectHandle::newName(token.getValue());
break;
case QPDFTokenizer::tt_word:
{
std::string const& value = token.getValue();
if ((value == "R") && (in_array || in_dictionary) &&
(olist.size() >= 2) &&
(olist[olist.size() - 1].isInteger()) &&
(olist[olist.size() - 2].isInteger()))
{
// Try to resolve indirect objects
object = QPDFObjectHandle::Factory::newIndirect(
this,
olist[olist.size() - 2].getIntValue(),
olist[olist.size() - 1].getIntValue());
olist.pop_back();
olist.pop_back();
}
else if ((value == "endobj") &&
(! (in_array || in_dictionary)))
{
// Nothing in the PDF spec appears to allow empty
// objects, but they have been encountered in
// actual PDF files and Adobe Reader appears to
// ignore them.
warn(QPDFExc(qpdf_e_damaged_pdf, input->getName(),
this->last_object_description,
input->getLastOffset(),
"empty object treated as null"));
object = QPDFObjectHandle::newNull();
input->seek(input->getLastOffset(), SEEK_SET);
}
else
{
throw QPDFExc(qpdf_e_damaged_pdf, input->getName(),
this->last_object_description,
input->getLastOffset(),
"unknown token while reading object (" +
value + ")");
}
}
break;
case QPDFTokenizer::tt_string:
{
std::string val = token.getValue();
if (this->encrypted && (! in_object_stream))
{
decryptString(val, objid, generation);
}
object = QPDFObjectHandle::newString(val);
}
break;
default:
throw QPDFExc(qpdf_e_damaged_pdf, input->getName(),
this->last_object_description,
input->getLastOffset(),
"unknown token type while reading object");
break;
}
if (in_dictionary || in_array)
{
if (! done)
{
olist.push_back(object);
}
}
else if (! object.isInitialized())
{
throw std::logic_error(
"INTERNAL ERROR: uninitialized object (token = " +
QUtil::int_to_string(token.getType()) +
", " + token.getValue() + ")");
}
else
{
done = true;
}
}
if (in_array)
{
object = QPDFObjectHandle::newArray(olist);
}
else if (in_dictionary)
{
// Convert list to map. Alternating elements are keys.
std::map<std::string, QPDFObjectHandle> dict;
if (olist.size() % 2)
{
QTC::TC("qpdf", "QPDF dictionary odd number of elements");
throw QPDFExc(
qpdf_e_damaged_pdf, input->getName(),
this->last_object_description, input->getLastOffset(),
"dictionary ending here has an odd number of elements");
}
for (unsigned int i = 0; i < olist.size(); i += 2)
{
QPDFObjectHandle key_obj = olist[i];
QPDFObjectHandle val = olist[i + 1];
if (! key_obj.isName())
{
throw QPDFExc(
qpdf_e_damaged_pdf,
input->getName(), this->last_object_description, offset,
std::string("dictionary key not name (") +
key_obj.unparse() + ")");
}
dict[key_obj.getName()] = val;
}
object = QPDFObjectHandle::newDictionary(dict);
if (! in_object_stream)
{
// check for stream
qpdf_offset_t cur_offset = input->tell();
if (readToken(input) ==
QPDFTokenizer::Token(QPDFTokenizer::tt_word, "stream"))
{
// The PDF specification states that the word "stream"
// should be followed by either a carriage return and
// a newline or by a newline alone. It specifically
// disallowed following it by a carriage return alone
// since, in that case, there would be no way to tell
// whether the NL in a CR NL sequence was part of the
// stream data. However, some readers, including
// Adobe reader, accept a carriage return by itself
// when followed by a non-newline character, so that's
// what we do here.
{
char ch;
if (input->read(&ch, 1) == 0)
{
// A premature EOF here will result in some
// other problem that will get reported at
// another time.
}
else if (ch == '\n')
{
// ready to read stream data
QTC::TC("qpdf", "QPDF stream with NL only");
}
else if (ch == '\r')
{
// Read another character
if (input->read(&ch, 1) != 0)
{
if (ch == '\n')
{
// Ready to read stream data
QTC::TC("qpdf", "QPDF stream with CRNL");
}
else
{
// Treat the \r by itself as the
// whitespace after endstream and
// start reading stream data in spite
// of not having seen a newline.
QTC::TC("qpdf", "QPDF stream with CR only");
input->unreadCh(ch);
warn(QPDFExc(
qpdf_e_damaged_pdf,
input->getName(),
this->last_object_description,
input->tell(),
"stream keyword followed"
" by carriage return only"));
}
}
}
else
{
QTC::TC("qpdf", "QPDF stream without newline");
warn(QPDFExc(qpdf_e_damaged_pdf, input->getName(),
this->last_object_description,
input->tell(),
"stream keyword not followed"
" by proper line terminator"));
}
}
// Must get offset before accessing any additional
// objects since resolving a previously unresolved
// indirect object will change file position.
qpdf_offset_t stream_offset = input->tell();
size_t length = 0;
try
{
if (dict.count("/Length") == 0)
{
QTC::TC("qpdf", "QPDF stream without length");
throw QPDFExc(qpdf_e_damaged_pdf, input->getName(),
this->last_object_description, offset,
"stream dictionary lacks /Length key");
}
QPDFObjectHandle length_obj = dict["/Length"];
if (! length_obj.isInteger())
{
QTC::TC("qpdf", "QPDF stream length not integer");
throw QPDFExc(qpdf_e_damaged_pdf, input->getName(),
this->last_object_description, offset,
"/Length key in stream dictionary is not "
"an integer");
}
length = length_obj.getIntValue();
input->seek(
stream_offset + (qpdf_offset_t)length, SEEK_SET);
if (! (readToken(input) ==
QPDFTokenizer::Token(
QPDFTokenizer::tt_word, "endstream")))
{
QTC::TC("qpdf", "QPDF missing endstream");
throw QPDFExc(qpdf_e_damaged_pdf, input->getName(),
this->last_object_description,
input->getLastOffset(),
"expected endstream");
}
}
catch (QPDFExc& e)
{
if (this->attempt_recovery)
{
// may throw an exception
length = recoverStreamLength(
input, objid, generation, stream_offset);
}
else
{
throw e;
}
}
object = QPDFObjectHandle::Factory::newStream(
this, objid, generation, object, stream_offset, length);
}
else
{
input->seek(cur_offset, SEEK_SET);
}
}
}
return object;
}
size_t
QPDF::recoverStreamLength(PointerHolder<InputSource> input,
int objid, int generation,

269
libqpdf/QPDFObjectHandle.cc
View File

@ -11,12 +11,15 @@
#include <qpdf/QPDF_Dictionary.hh>
#include <qpdf/QPDF_Stream.hh>
#include <qpdf/QPDF_Reserved.hh>
#include <qpdf/BufferInputSource.hh>
#include <qpdf/QPDFExc.hh>
#include <qpdf/QTC.hh>
#include <qpdf/QUtil.hh>
#include <stdexcept>
#include <stdlib.h>
#include <ctype.h>
QPDFObjectHandle::QPDFObjectHandle() :
initialized(false),
@ -398,6 +401,13 @@ QPDFObjectHandle::getDict()
return dynamic_cast<QPDF_Stream*>(obj.getPointer())->getDict();
}
void
QPDFObjectHandle::replaceDict(QPDFObjectHandle new_dict)
{
assertStream();
dynamic_cast<QPDF_Stream*>(obj.getPointer())->replaceDict(new_dict);
}
PointerHolder<Buffer>
QPDFObjectHandle::getStreamData()
{
@ -598,6 +608,265 @@ QPDFObjectHandle::unparseResolved()
return this->obj->unparse();
}
QPDFObjectHandle
QPDFObjectHandle::parse(std::string const& object_str,
std::string const& object_description)
{
PointerHolder<InputSource> input =
new BufferInputSource("parsed object", object_str);
QPDFTokenizer tokenizer;
bool empty = false;
QPDFObjectHandle result =
parse(input, object_description, tokenizer, empty, 0, 0);
size_t offset = (size_t) input->tell();
while (offset < object_str.length())
{
if (! isspace(object_str[offset]))
{
QTC::TC("qpdf", "QPDFObjectHandle trailing data in parse");
throw QPDFExc(qpdf_e_damaged_pdf, input->getName(),
object_description,
input->getLastOffset(),
"trailing data found parsing object from string");
}
++offset;
}
return result;
}
QPDFObjectHandle
QPDFObjectHandle::parse(PointerHolder<InputSource> input,
std::string const& object_description,
QPDFTokenizer& tokenizer, bool& empty,
StringDecrypter* decrypter, QPDF* context)
{
return parseInternal(input, object_description, tokenizer, empty,
decrypter, context, false, false);
}
QPDFObjectHandle
QPDFObjectHandle::parseInternal(PointerHolder<InputSource> input,
std::string const& object_description,
QPDFTokenizer& tokenizer, bool& empty,
StringDecrypter* decrypter, QPDF* context,
bool in_array, bool in_dictionary)
{
empty = false;
if (in_dictionary && in_array)
{
// Although dictionaries and arrays arbitrarily nest, these
// variables indicate what is at the top of the stack right
// now, so they can, by definition, never both be true.
throw std::logic_error(
"INTERNAL ERROR: parseInternal: in_dict && in_array");
}
QPDFObjectHandle object;
qpdf_offset_t offset = input->tell();
std::vector<QPDFObjectHandle> olist;
bool done = false;
while (! done)
{
object = QPDFObjectHandle();
QPDFTokenizer::Token token =
tokenizer.readToken(input, object_description);
switch (token.getType())
{
case QPDFTokenizer::tt_brace_open:
case QPDFTokenizer::tt_brace_close:
// Don't know what to do with these for now
QTC::TC("qpdf", "QPDFObjectHandle bad brace");
throw QPDFExc(qpdf_e_damaged_pdf, input->getName(),
object_description,
input->getLastOffset(),
"unexpected brace token");
break;
case QPDFTokenizer::tt_array_close:
if (in_array)
{
done = true;
}
else
{
QTC::TC("qpdf", "QPDFObjectHandle bad array close");
throw QPDFExc(qpdf_e_damaged_pdf, input->getName(),
object_description,
input->getLastOffset(),
"unexpected array close token");
}
break;
case QPDFTokenizer::tt_dict_close:
if (in_dictionary)
{
done = true;
}
else
{
QTC::TC("qpdf", "QPDFObjectHandle bad dictionary close");
throw QPDFExc(qpdf_e_damaged_pdf, input->getName(),
object_description,
input->getLastOffset(),
"unexpected dictionary close token");
}
break;
case QPDFTokenizer::tt_array_open:
object = parseInternal(
input, object_description, tokenizer, empty,
decrypter, context, true, false);
break;
case QPDFTokenizer::tt_dict_open:
object = parseInternal(
input, object_description, tokenizer, empty,
decrypter, context, false, true);
break;
case QPDFTokenizer::tt_bool:
object = newBool((token.getValue() == "true"));
break;
case QPDFTokenizer::tt_null:
object = newNull();
break;
case QPDFTokenizer::tt_integer:
object = newInteger(QUtil::string_to_ll(token.getValue().c_str()));
break;
case QPDFTokenizer::tt_real:
object = newReal(token.getValue());
break;
case QPDFTokenizer::tt_name:
object = newName(token.getValue());
break;
case QPDFTokenizer::tt_word:
{
std::string const& value = token.getValue();
if ((value == "R") && (in_array || in_dictionary) &&
(olist.size() >= 2) &&
(olist[olist.size() - 1].isInteger()) &&
(olist[olist.size() - 2].isInteger()))
{
if (context == 0)
{
QTC::TC("qpdf", "QPDFObjectHandle indirect without context");
throw std::logic_error(
"QPDFObjectHandle::parse called without context"
" on an object with indirect references");
}
// Try to resolve indirect objects
object = newIndirect(
context,
olist[olist.size() - 2].getIntValue(),
olist[olist.size() - 1].getIntValue());
olist.pop_back();
olist.pop_back();
}
else if ((value == "endobj") &&
(! (in_array || in_dictionary)))
{
// We just saw endobj without having read
// anything. Treat this as a null and do not move
// the input source's offset.
object = newNull();
input->seek(input->getLastOffset(), SEEK_SET);
empty = true;
}
else
{
throw QPDFExc(qpdf_e_damaged_pdf, input->getName(),
object_description,
input->getLastOffset(),
"unknown token while reading object (" +
value + ")");
}
}
break;
case QPDFTokenizer::tt_string:
{
std::string val = token.getValue();
if (decrypter)
{
decrypter->decryptString(val);
}
object = QPDFObjectHandle::newString(val);
}
break;
default:
throw QPDFExc(qpdf_e_damaged_pdf, input->getName(),
object_description,
input->getLastOffset(),
"unknown token type while reading object");
break;
}
if (in_dictionary || in_array)
{
if (! done)
{
olist.push_back(object);
}
}
else if (! object.isInitialized())
{
throw std::logic_error(
"INTERNAL ERROR: uninitialized object (token = " +
QUtil::int_to_string(token.getType()) +
", " + token.getValue() + ")");
}
else
{
done = true;
}
}
if (in_array)
{
object = newArray(olist);
}
else if (in_dictionary)
{
// Convert list to map. Alternating elements are keys.
std::map<std::string, QPDFObjectHandle> dict;
if (olist.size() % 2)
{
QTC::TC("qpdf", "QPDFObjectHandle dictionary odd number of elements");
throw QPDFExc(
qpdf_e_damaged_pdf, input->getName(),
object_description, input->getLastOffset(),
"dictionary ending here has an odd number of elements");
}
for (unsigned int i = 0; i < olist.size(); i += 2)
{
QPDFObjectHandle key_obj = olist[i];
QPDFObjectHandle val = olist[i + 1];
if (! key_obj.isName())
{
throw QPDFExc(
qpdf_e_damaged_pdf,
input->getName(), object_description, offset,
std::string("dictionary key not name (") +
key_obj.unparse() + ")");
}
dict[key_obj.getName()] = val;
}
object = newDictionary(dict);
}
return object;
}
QPDFObjectHandle
QPDFObjectHandle::newIndirect(QPDF* qpdf, int objid, int generation)
{

15
libqpdf/QPDF_Stream.cc
View File

@ -464,3 +464,18 @@ QPDF_Stream::replaceFilterData(QPDFObjectHandle const& filter,
"/Length", QPDFObjectHandle::newInteger((int)length));
}
}
void
QPDF_Stream::replaceDict(QPDFObjectHandle new_dict)
{
this->stream_dict = new_dict;
QPDFObjectHandle length_obj = new_dict.getKey("/Length");
if (length_obj.isInteger())
{
this->length = length_obj.getIntValue();
}
else
{
this->length = 0;
}
}

2
libqpdf/qpdf/QPDF_Stream.hh
View File

@ -32,6 +32,8 @@ class QPDF_Stream: public QPDFObject
QPDFObjectHandle const& filter,
QPDFObjectHandle const& decode_parms);
void replaceDict(QPDFObjectHandle new_dict);
// Replace object ID and generation. This may only be called if
// object ID and generation are 0. It is used by QPDFObjectHandle
// when adding streams to files.

23
qpdf/pdf_from_scratch.cc
View File

@ -38,25 +38,20 @@ void runtest(int n)
// Create a minimal PDF from scratch.
QPDFObjectHandle font = pdf.makeIndirectObject(
QPDFObjectHandle::newDictionary());
font.replaceKey("/Type", newName("/Font"));
font.replaceKey("/Subtype", newName("/Type1"));
font.replaceKey("/Name", newName("/F1"));
font.replaceKey("/BaseFont", newName("/Helvetica"));
font.replaceKey("/Encoding", newName("/WinAnsiEncoding"));
QPDFObjectHandle::parse("<<"
" /Type /Font"
" /Subtype /Type1"
" /Name /F1"
" /BaseFont /Helvetica"
" /Encoding /WinAnsiEncoding"
">>"));
QPDFObjectHandle procset = pdf.makeIndirectObject(
QPDFObjectHandle::newArray());
procset.appendItem(newName("/PDF"));
procset.appendItem(newName("/Text"));
QPDFObjectHandle::parse("[/PDF /Text]"));
QPDFObjectHandle contents = createPageContents(pdf, "First Page");
QPDFObjectHandle mediabox = QPDFObjectHandle::newArray();
mediabox.appendItem(QPDFObjectHandle::newInteger(0));
mediabox.appendItem(QPDFObjectHandle::newInteger(0));
mediabox.appendItem(QPDFObjectHandle::newInteger(612));
mediabox.appendItem(QPDFObjectHandle::newInteger(792));
QPDFObjectHandle mediabox = QPDFObjectHandle::parse("[0 0 612 792]");
QPDFObjectHandle rfont = QPDFObjectHandle::newDictionary();
rfont.replaceKey("/F1", font);

10
qpdf/qpdf.testcov
View File

@ -60,13 +60,13 @@ QPDF missing trailer 0
QPDF trailer lacks size 0
QPDF trailer size not integer 0
QPDF trailer prev not integer 0
QPDF bad brace 0
QPDF bad array close 0
QPDF dictionary odd number of elements 0
QPDFObjectHandle bad brace 0
QPDFObjectHandle bad array close 0
QPDFObjectHandle dictionary odd number of elements 0
QPDF stream without length 0
QPDF stream length not integer 0
QPDF missing endstream 0
QPDF bad dictionary close 0
QPDFObjectHandle bad dictionary close 0
QPDF can't find xref 0
QPDF_Tokenizer bad ) 0
QPDF_Tokenizer bad > 0
@ -235,3 +235,5 @@ QPDF not copying pages object 0
QPDF insert foreign page 0
QPDFWriter foreign object 0
QPDFWriter copy use_aes 1
QPDFObjectHandle indirect without context 0
QPDFObjectHandle trailing data in parse 0

6
qpdf/qtest/qpdf.test
View File

@ -149,7 +149,7 @@ $td->runtest("remove page we don't have",
$td->NORMALIZE_NEWLINES);
# ----------
$td->notify("--- Miscellaneous Tests ---");
$n_tests += 44;
$n_tests += 45;
$td->runtest("qpdf version",
{$td->COMMAND => "qpdf --version"},
@ -370,6 +370,10 @@ $td->runtest("detect foreign object in write",
" copy-foreign-objects-in.pdf minimal.pdf"},
{$td->FILE => "foreign-in-write.out", $td->EXIT_STATUS => 0},
$td->NORMALIZE_NEWLINES);
$td->runtest("parse objects from string",
{$td->COMMAND => "test_driver 31 minimal.pdf"}, # file not used
{$td->FILE => "parse-object.out", $td->EXIT_STATUS => 0},
$td->NORMALIZE_NEWLINES);
show_ntests();
# ----------

2
qpdf/qtest/qpdf/bad22.out
View File

@ -1 +1 @@
bad22.pdf (object 4 0, file position 317): stream dictionary lacks /Length key
bad22.pdf (object 4 0, file position 314): stream dictionary lacks /Length key

2
qpdf/qtest/qpdf/bad23.out
View File

@ -1 +1 @@
bad23.pdf (object 4 0, file position 317): /Length key in stream dictionary is not an integer
bad23.pdf (object 4 0, file position 314): /Length key in stream dictionary is not an integer

4
qpdf/qtest/qpdf/parse-object.out Normal file
View File

@ -0,0 +1,4 @@
[ /name 16059 3.14159 false << /key true /other [ (string1) (string2) ] >> null ]
logic error parsing indirect: QPDFObjectHandle::parse called without context on an object with indirect references
trailing data: parsed object (trailing test): trailing data found parsing object from string
test 31 done

32
qpdf/test_driver.cc
View File

@ -1054,6 +1054,38 @@ void runtest(int n, char const* filename1, char const* filename2)
<< std::endl;
}
}
else if (n == 31)
{
// Test object parsing from a string. The input file is not used.
QPDFObjectHandle o1 =
QPDFObjectHandle::parse(
"[/name 16059 3.14159 false\n"
" << /key true /other [ (string1) (string2) ] >> null]");
std::cout << o1.unparse() << std::endl;
QPDFObjectHandle o2 = QPDFObjectHandle::parse(" 12345 \f ");
assert(o2.isInteger() && (o2.getIntValue() == 12345));
try
{
QPDFObjectHandle::parse("[1 0 R]", "indirect test");
std::cout << "oops -- didn't throw" << std::endl;
}
catch (std::logic_error e)
{
std::cout << "logic error parsing indirect: " << e.what()
<< std::endl;
}
try
{
QPDFObjectHandle::parse("0 trailing", "trailing test");
std::cout << "oops -- didn't throw" << std::endl;
}
catch (std::runtime_error e)
{
std::cout << "trailing data: " << e.what()
<< std::endl;
}
}
else
{
throw std::runtime_error(std::string("invalid test ") +