// Copyright (c) 2005-2021 Jay Berkenbilt

// Copyright (c) 2022-2026 Jay Berkenbilt and Manfred Holger

//

// This file is part of qpdf.

//

// Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except

// in compliance with the License. You may obtain a copy of the License at

//

//   http://www.apache.org/licenses/LICENSE-2.0

//

// Unless required by applicable law or agreed to in writing, software distributed under the License

// is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express

// or implied. See the License for the specific language governing permissions and limitations under

// the License.

//

// Versions of qpdf prior to version 7 were released under the terms of version 2.0 of the Artistic

// License. At your option, you may continue to consider qpdf to be licensed under those terms.

// Please see the manual for additional information.

#ifndef QPDF_HH

#define QPDF_HH

#include <qpdf/DLL.h>

#include <qpdf/Types.h>

#include <bitset>

#include <cstdio>

#include <functional>

#include <iostream>

#include <list>

#include <map>

#include <memory>

#include <string>

#include <string_view>

#include <vector>

#include <qpdf/Buffer.hh>

#include <qpdf/InputSource.hh>

#include <qpdf/PDFVersion.hh>

#include <qpdf/QPDFExc.hh>

#include <qpdf/QPDFObjGen.hh>

#include <qpdf/QPDFObjectHandle.hh>

#include <qpdf/QPDFStreamFilter.hh>

#include <qpdf/QPDFTokenizer.hh>

#include <qpdf/QPDFWriter.hh>

#include <qpdf/QPDFXRefEntry.hh>

class QPDFLogger;

class QPDF

{

  public:

    // Get the current version of the QPDF software. See also qpdf/DLL.h

    QPDF_DLL

    static std::string const& QPDFVersion();

    QPDF_DLL

    QPDF();

    QPDF_DLL

    ~QPDF();

    QPDF_DLL

    static std::shared_ptr<QPDF> create();

    // Associate a file with a QPDF object and do initial parsing of the file.  PDF objects are not

    // read until they are needed.  A QPDF object may be associated with only one file in its

    // lifetime.  This method must be called before any methods that potentially ask for information

    // about the PDF file are called. Prior to calling this, the only methods that are allowed are

    // those that set parameters.  If the input file is not encrypted, either a null password or an

    // empty password can be used.  If the file is encrypted, either the user password or the owner

    // password may be supplied. The method setPasswordIsHexKey may be called prior to calling this

    // method or any of the other process methods to force the password to be interpreted as a raw

    // encryption key. See comments on setPasswordIsHexKey for more information.

    QPDF_DLL

    void processFile(char const* filename, char const* password = nullptr);

    // Parse a PDF from a stdio FILE*.  The FILE must be open in binary mode and must be seekable.

    // It may be open read only. This works exactly like processFile except that the PDF file is

    // read from an already opened FILE*.  If close_file is true, the file will be closed at the

    // end.  Otherwise, the caller is responsible for closing the file.

    QPDF_DLL

    void processFile(

        char const* description, FILE* file, bool close_file, char const* password = nullptr);

    // Parse a PDF file loaded into a memory buffer.  This works exactly like processFile except

    // that the PDF file is in memory instead of on disk.  The description appears in any warning or

    // error message in place of the file name. The buffer is owned by the caller and must remain

    // valid for the lifetime of the QPDF object.

    QPDF_DLL

    void processMemoryFile(

        char const* description, char const* buf, size_t length, char const* password = nullptr);

    // Parse a PDF file loaded from a custom InputSource.  If you have your own method of retrieving

    // a PDF file, you can subclass InputSource and use this method.

    QPDF_DLL

    void processInputSource(std::shared_ptr<InputSource>, char const* password = nullptr);

    // Create a PDF from an input source that contains JSON as written by writeJSON (or qpdf

    // --json-output, version 2 or higher). The JSON must be a complete representation of a PDF. See

    // "qpdf JSON" in the manual for details. The input JSON may be arbitrarily large. QPDF does not

    // load stream data into memory for more than one stream at a time, even if the stream data is

    // specified inline.

    QPDF_DLL

    void createFromJSON(std::string const& json_file);

    QPDF_DLL

    void createFromJSON(std::shared_ptr<InputSource>);

    // Update a PDF from an input source that contains JSON in the same format as is written by

    // writeJSON (or qpdf --json-output, version 2 or higher). Objects in the PDF and not in the

    // JSON are not modified. See "qpdf JSON" in the manual for details. As with createFromJSON, the

    // input JSON may be arbitrarily large.

    QPDF_DLL

    void updateFromJSON(std::string const& json_file);

    QPDF_DLL

    void updateFromJSON(std::shared_ptr<InputSource>);

    // Write qpdf JSON format to the pipeline "p". The only supported version is 2. The finish()

    // method is not called on the pipeline.

    //

    // The decode_level parameter controls which streams are uncompressed in the JSON. Use

    // qpdf_dl_none to preserve all stream data exactly as it appears in the input. The possible

    // values for json_stream_data can be found in qpdf/Constants.h and correspond to the

    // --json-stream-data command-line argument. If json_stream_data is qpdf_sj_file, file_prefix

    // must be specified. Each stream will be written to a file whose path is constructed by

    // appending "-nnn" to file_prefix, where "nnn" is the object number (not zero-filled). If

    // wanted_objects is empty, write all objects. Otherwise, write only objects whose keys are in

    // wanted_objects. Keys may be either "trailer" or of the form "obj:n n R". Invalid keys are

    // ignored. This corresponds to the --json-object command-line argument.

    //

    // QPDF is efficient with regard to memory when writing, allowing you to write arbitrarily large

    // PDF files to a pipeline. You can use a pipeline like Pl_Buffer or Pl_String to capture the

    // JSON output in memory, but do so with caution as this will allocate enough memory to hold the

    // entire PDF file.

    QPDF_DLL

    void writeJSON(

        int version,

        Pipeline* p,

        qpdf_stream_decode_level_e decode_level,

        qpdf_json_stream_data_e json_stream_data,

        std::string const& file_prefix,

        std::set<std::string> wanted_objects);

    // This version of writeJSON enables writing only the "qpdf" key of an in-progress dictionary.

    // If the value of "complete" is true, a complete JSON object containing only the "qpdf" key is

    // written to the pipeline. If the value of "complete" is false, the "qpdf" key and its value

    // are written to the pipeline assuming that a dictionary is already open. The parameter

    // first_key indicates whether this is the first key in an in-progress dictionary. It will be

    // set to false by writeJSON. The "qpdf" key and value are written as if at depth 1 in a

    // prettified JSON output. Remaining arguments are the same as the above version.

    QPDF_DLL

    void writeJSON(

        int version,

        Pipeline* p,

        bool complete,

        bool& first_key,

        qpdf_stream_decode_level_e decode_level,

        qpdf_json_stream_data_e json_stream_data,

        std::string const& file_prefix,

        std::set<std::string> wanted_objects);

    // Close or otherwise release the input source. Once this has been called, no other methods of

    // qpdf can be called safely except for getWarnings and anyWarnings(). After this has been

    // called, it is safe to perform operations on the input file such as deleting or renaming it.

    QPDF_DLL

    void closeInputSource();

    // For certain forensic or investigatory purposes, it may sometimes be useful to specify the

    // encryption key directly, even though regular PDF applications do not provide a way to do

    // this. Calling setPasswordIsHexKey(true) before calling any of the process methods will bypass

    // the normal encryption key computation or recovery mechanisms and interpret the bytes in the

    // password as a hex-encoded encryption key. Note that we hex-encode the key because it may

    // contain null bytes and therefore can't be represented in a char const*.

    QPDF_DLL

    void setPasswordIsHexKey(bool);

    // Create a QPDF object for an empty PDF.  This PDF has no pages or objects other than a minimal

    // trailer, a document catalog, and a /Pages tree containing zero pages.  Pages and other

    // objects can be added to the file in the normal way, and the trailer and document catalog can

    // be mutated.  Calling this method is equivalent to calling processFile on an equivalent PDF

    // file.  See the pdf-create.cc example for a demonstration of how to use this method to create

    // a PDF file from scratch.

    QPDF_DLL

    void emptyPDF();

    // From 10.1: register a new filter implementation for a specific stream filter. You can add

    // your own implementations for new filter types or override existing ones provided by the

    // library. Registered stream filters are used for decoding only as you can override encoding

    // with stream data providers. For example, you could use this method to add support for one of

    // the other filter types by using additional third-party libraries that qpdf does not presently

    // use. The standard filters are implemented using QPDFStreamFilter classes.

    QPDF_DLL

    static void registerStreamFilter(

        std::string const& filter_name, std::function<std::shared_ptr<QPDFStreamFilter>()> factory);

    // Parameter settings

    // To capture or redirect output, configure the logger returned by getLogger(). By default, all

    // QPDF and QPDFJob objects share the global logger. If you need a private logger for some

    // reason, pass a new one to setLogger(). See comments in QPDFLogger.hh for details on

    // configuring the logger.

    //

    // Note that no normal QPDF operations generate output to standard output, so for applications

    // that just wish to avoid creating output for warnings and don't call any check functions,

    // calling setSuppressWarnings(true) is sufficient.

    QPDF_DLL

    std::shared_ptr<QPDFLogger> getLogger();

    QPDF_DLL

    void setLogger(std::shared_ptr<QPDFLogger>);

    // This deprecated method is the old way to capture output, but it didn't capture all output.

    // See comments above for getLogger and setLogger. This will be removed in QPDF 12. For now, it

    // configures a private logger, separating this object from the default logger, and calls

    // setOutputStreams on that logger. See QPDFLogger.hh for additional details.

    [[deprecated("configure logger from getLogger() or call setLogger()")]] QPDF_DLL void

    setOutputStreams(std::ostream* out_stream, std::ostream* err_stream);

    // If true, ignore any cross-reference streams in a hybrid file (one that contains both

    // cross-reference streams and cross-reference tables).  This can be useful for testing to

    // ensure that a hybrid file would work with an older reader.

    QPDF_DLL

    void setIgnoreXRefStreams(bool);

    // By default, any warnings are issued to std::cerr or the error stream specified in a call to

    // setOutputStreams as they are encountered.  If this method is called with a true value,

    // reporting of warnings is suppressed.  You may still retrieve warnings by calling getWarnings.

    QPDF_DLL

    void setSuppressWarnings(bool);

    // Set the maximum number of warnings. A QPDFExc is thrown if the limit is exceeded.

    QPDF_DLL

    void setMaxWarnings(size_t);

    // By default, QPDF will try to recover if it finds certain types of errors in PDF files.  If

    // turned off, it will throw an exception on the first such problem it finds without attempting

    // recovery.

    QPDF_DLL

    void setAttemptRecovery(bool);

    // Tell other QPDF objects that streams copied from this QPDF need to be fully copied when

    // copyForeignObject is called on them. Calling setIgnoreXRefStreams(true) on a QPDF object

    // makes it possible for the object and its input source to disappear before streams copied from

    // it are written with the destination QPDF object. Confused? Ordinarily, if you are going to

    // copy objects from a source QPDF object to a destination QPDF object using copyForeignObject

    // or addPage, the source object's input source must stick around until after the destination

    // PDF is written. If you call this method on the source QPDF object, it sends a signal to the

    // destination object that it must fully copy the stream data when copyForeignObject. It will do

    // this by making a copy in RAM. Ordinarily the stream data is copied lazily to avoid

    // unnecessary duplication of the stream data. Note that the stream data is copied into RAM only

    // once regardless of how many objects the stream is copied into. The result is that, if you

    // called setImmediateCopyFrom(true) on a given QPDF object prior to copying any of its streams,

    // you do not need to keep it or its input source around after copying its objects to another

    // QPDF. This is true even if the source streams use StreamDataProvider. Note that this method

    // is called on the QPDF object you are copying FROM, not the one you are copying to. The

    // reasoning for this is that there's no reason a given QPDF may not get objects copied to it

    // from a variety of other objects, some transient and some not. Since what's relevant is

    // whether the source QPDF is transient, the method must be called on the source QPDF, not the

    // destination one. This method will make a copy of the stream in RAM, so be sure you have

    // enough memory to simultaneously hold all the streams you're copying.

    QPDF_DLL

    void setImmediateCopyFrom(bool);

    // Other public methods

    // Return the list of warnings that have been issued so far and clear the list.  This method may

    // be called even if processFile throws an exception.  Note that if setSuppressWarnings was not

    // called or was called with a false value, any warnings retrieved here will have already been

    // output.

    QPDF_DLL

    std::vector<QPDFExc> getWarnings();

    // Indicate whether any warnings have been issued so far. Does not clear the list of warnings.

    QPDF_DLL

    bool anyWarnings() const;

    // Indicate the number of warnings that have been issued since the last call to getWarnings.

    // Does not clear the list of warnings.

    QPDF_DLL

    size_t numWarnings() const;

    // Return an application-scoped unique ID for this QPDF object. This is not a globally unique

    // ID. It is constructed using a timestamp and a random number and is intended to be unique

    // among QPDF objects that are created by a single run of an application. While it's very likely

    // that these are actually globally unique, it is not recommended to use them for long-term

    // purposes.

    QPDF_DLL

    unsigned long long getUniqueId() const;

    // Issue a warning on behalf of this QPDF object. It will be emitted with other warnings,

    // following warning suppression rules, and it will be available with getWarnings().

    QPDF_DLL

    void warn(QPDFExc const& e);

    // Same as above but creates the QPDFExc object using the arguments passed to warn. The filename

    // argument to QPDFExc is omitted. This method uses the filename associated with the QPDF

    // object.

    QPDF_DLL

    void warn(

        qpdf_error_code_e error_code,

        std::string const& object,

        qpdf_offset_t offset,

        std::string const& message);

    // Return the filename associated with the QPDF object.

    QPDF_DLL

    std::string getFilename() const;

    // Return PDF Version and extension level together as a PDFVersion object

    QPDF_DLL

    PDFVersion getVersionAsPDFVersion();

    // Return just the PDF version from the file

    QPDF_DLL

    std::string getPDFVersion() const;

    QPDF_DLL

    int getExtensionLevel();

    QPDF_DLL

    QPDFObjectHandle getTrailer();

    QPDF_DLL

    QPDFObjectHandle getRoot();

    QPDF_DLL

    std::map<QPDFObjGen, QPDFXRefEntry> getXRefTable();

    // Public factory methods

    // Create a new stream.  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.  Alternatively, you can create a new dictionary and

    // call replaceDict to install it.

    QPDF_DLL

    QPDFObjectHandle newStream();

    // Create a new stream.  Use the given buffer as the stream data.  The stream dictionary's

    // /Length key will automatically be set to the size of the data buffer.  If additional keys are

    // required, the stream's dictionary may be retrieved by calling getDict(), and the resulting

    // dictionary may be modified.  This method is just a convenient wrapper around the newStream()

    // and replaceStreamData().  It is a convenience methods for streams that require no parameters

    // beyond the stream length. Note that you don't have to deal with compression yourself if you

    // use QPDFWriter.  By default, QPDFWriter will automatically compress uncompressed stream data.

    // Example programs are provided that illustrate this.

    QPDF_DLL

    QPDFObjectHandle newStream(std::shared_ptr<Buffer> data);

    // Create new stream with data from string.  This method will create a copy of the data rather

    // than using the user-provided buffer as in the std::shared_ptr<Buffer> version of newStream.

    QPDF_DLL

    QPDFObjectHandle newStream(std::string const& data);

    // A reserved object is a special sentinel used for qpdf to reserve a spot for an object that is

    // going to be added to the QPDF object.  Normally you don't have to use this type since you can

    // just call QPDF::makeIndirectObject.  However, in some cases, if you have to create objects

    // with circular references, you may need to create a reserved object so that you can have a

    // reference to it and then replace the object later.  Reserved objects have the special

    // property that they can't be resolved to direct objects.  This makes it possible to replace a

    // reserved object with a new object while preserving existing references to them.  When you are

    // ready to replace a reserved object with its replacement, use QPDF::replaceReserved for this

    // purpose rather than the more general QPDF::replaceObject.  It is an error to try to write a

    // QPDF with QPDFWriter if it has any reserved objects in it.

    QPDF_DLL

    QPDFObjectHandle newReserved();

    QPDF_DLL

    QPDFObjectHandle newIndirectNull();

    // Install this object handle as an indirect object and return an indirect reference to it.

    QPDF_DLL

    QPDFObjectHandle makeIndirectObject(QPDFObjectHandle);

    // Retrieve an object by object ID and generation. Returns an indirect reference to it. The

    // getObject() methods were added for qpdf 11.

    QPDF_DLL

    QPDFObjectHandle getObject(QPDFObjGen);

    QPDF_DLL

    QPDFObjectHandle getObject(int objid, int generation);

    // These are older methods, but there is no intention to deprecate

    // them.

    QPDF_DLL

    QPDFObjectHandle getObjectByObjGen(QPDFObjGen);

    QPDF_DLL

    QPDFObjectHandle getObjectByID(int objid, int generation);

    // Replace the object with the given object id with the given object. The object handle passed

    // in must be a direct object, though it may contain references to other indirect objects within

    // it. Prior to qpdf 10.2.1, after calling this method, existing QPDFObjectHandle instances that

    // pointed to the original object still pointed to the original object, resulting in confusing

    // and incorrect behavior. This was fixed in 10.2.1, so existing QPDFObjectHandle objects will

    // start pointing to the newly replaced object. Note that replacing an object with

    // QPDFObjectHandle::newNull() effectively removes the object from the file since a non-existent

    // object is treated as a null object. To replace a reserved object, call replaceReserved

    // instead.

    QPDF_DLL

    void replaceObject(QPDFObjGen og, QPDFObjectHandle);

    QPDF_DLL

    void replaceObject(int objid, int generation, QPDFObjectHandle);

    // Swap two objects given by ID. Prior to qpdf 10.2.1, existing QPDFObjectHandle instances that

    // reference them objects not notice the swap, but this was fixed in 10.2.1.

    QPDF_DLL

    void swapObjects(QPDFObjGen og1, QPDFObjGen og2);

    QPDF_DLL

    void swapObjects(int objid1, int generation1, int objid2, int generation2);

    // Replace a reserved object.  This is a wrapper around replaceObject but it guarantees that the

    // underlying object is a reserved object or a null object.  After this call, reserved will

    // be a reference to replacement.

    QPDF_DLL

    void replaceReserved(QPDFObjectHandle reserved, QPDFObjectHandle replacement);

    // Copy an object from another QPDF to this one. Starting with qpdf version 8.3.0, it is no

    // longer necessary to keep the original QPDF around after the call to copyForeignObject as long

    // as the source of any copied stream data is still available. Usually this means you just have

    // to keep the input file around, not the QPDF object. The exception to this is if you copy a

    // stream that gets its data from a QPDFObjectHandle::StreamDataProvider. In this case only, the

    // original stream's QPDF object must stick around because the QPDF object is itself the source

    // of the original stream data. For a more in-depth discussion, please see the TODO file.

    // Starting in 8.4.0, you can call setImmediateCopyFrom(true) on the SOURCE QPDF object (the one

    // you're copying FROM). If you do this prior to copying any of its objects, then neither the

    // source QPDF object nor its input source needs to stick around at all regardless of the

    // source. The cost is that the stream data is copied into RAM at the time copyForeignObject is

    // called. See setImmediateCopyFrom for more information.

    //

    // The return value of this method is an indirect reference to the copied object in this file.

    // This method is intended to be used to copy non-page objects. To copy page objects, pass the

    // foreign page object directly to addPage (or addPageAt). If you copy objects that contain

    // references to pages, you should copy the pages first using addPage(At). Otherwise references

    // to the pages that have not been copied will be replaced with nulls. It is possible to use

    // copyForeignObject on page objects if you are not going to use them as pages. Doing so copies

    // the object normally but does not update the page structure. For example, it is a valid use

    // case to use copyForeignObject for a page that you are going to turn into a form XObject,

    // though you can also use QPDFPageObjectHelper::getFormXObjectForPage for that purpose.

    //

    // When copying objects with this method, object structure will be preserved, so all indirectly

    // referenced indirect objects will be copied as well.  This includes any circular references

    // that may exist.  The QPDF object keeps a record of what has already been copied, so shared

    // objects will not be copied multiple times.  This also means that if you mutate an object that

    // has already been copied and try to copy it again, it won't work since the modified object

    // will not be recopied.  Therefore, you should do all mutation on the original file that you

    // are going to do before you start copying its objects to a new file.

    QPDF_DLL

    QPDFObjectHandle copyForeignObject(QPDFObjectHandle foreign);

    // Encryption support

    enum encryption_method_e { e_none, e_unknown, e_rc4, e_aes, e_aesv3 };

    // To be removed from the public API in qpdf 13. See

    // <https:manual.qpdf.org/release-notes.html#r12-3-0-deprecate>.

    class EncryptionData

    {

      public:

        // This class holds data read from the encryption dictionary.

        EncryptionData(

            int V,

            int R,

            int Length_bytes,

            int P,

            std::string const& O,

            std::string const& U,

            std::string const& OE,

            std::string const& UE,

            std::string const& Perms,

            std::string const& id1,

            bool encrypt_metadata) :

            V(V),

            R(R),

            Length_bytes(Length_bytes),

            P(P),

            O(O),

            U(U),

            OE(OE),

            UE(UE),

            Perms(Perms),

            id1(id1),

            encrypt_metadata(encrypt_metadata)

        {

        }

        int getV() const;

        int getR() const;

        int getLengthBytes() const;

        int getP() const;

        std::string const& getO() const;

        std::string const& getU() const;

        std::string const& getOE() const;

        std::string const& getUE() const;

        std::string const& getPerms() const;

        std::string const& getId1() const;

        bool getEncryptMetadata() const;

        void setO(std::string const&);

        void setU(std::string const&);

        void setV5EncryptionParameters(

            std::string const& O,

            std::string const& OE,

            std::string const& U,

            std::string const& UE,

            std::string const& Perms);

      private:

        EncryptionData(EncryptionData const&) = delete;

        EncryptionData& operator=(EncryptionData const&) = delete;

        int V;

        int R;

        int Length_bytes;

        int P;

        std::string O;

        std::string U;

        std::string OE;

        std::string UE;

        std::string Perms;

        std::string id1;

        bool encrypt_metadata;

    };

    QPDF_DLL

    bool isEncrypted() const;

    QPDF_DLL

    bool isEncrypted(int& R, int& P);

    QPDF_DLL

    bool isEncrypted(

        int& R,

        int& P,

        int& V,

        encryption_method_e& stream_method,

        encryption_method_e& string_method,

        encryption_method_e& file_method);

    QPDF_DLL

    bool ownerPasswordMatched() const;

    QPDF_DLL

    bool userPasswordMatched() const;

    // Encryption permissions -- not enforced by QPDF

    QPDF_DLL

    bool allowAccessibility();

    QPDF_DLL

    bool allowExtractAll();

    QPDF_DLL

    bool allowPrintLowRes();

    QPDF_DLL

    bool allowPrintHighRes();

    QPDF_DLL

    bool allowModifyAssembly();

    QPDF_DLL

    bool allowModifyForm();

    QPDF_DLL

    bool allowModifyAnnotation();

    QPDF_DLL

    bool allowModifyOther();

    QPDF_DLL

    bool allowModifyAll();

    // Helper function to trim padding from user password.  Calling trim_user_password on the result

    // of getPaddedUserPassword gives getTrimmedUserPassword's result.

    QPDF_DLL

    static void trim_user_password(std::string& user_password);

    QPDF_DLL

    static std::string compute_data_key(

        std::string const& encryption_key,

        int objid,

        int generation,

        bool use_aes,

        int encryption_V,

        int encryption_R);

    // To be removed in qpdf 13. See <https:manual.qpdf.org/release-notes.html#r12-3-0-deprecate>.

    [[deprecated("to be removed in qpdf 13")]]

    QPDF_DLL static std::string

    compute_encryption_key(std::string const& password, EncryptionData const& data);

    QPDF_DLL

    static void compute_encryption_O_U(

        char const* user_password,

        char const* owner_password,

        int V,

        int R,

        int key_len,

        int P,

        bool encrypt_metadata,

        std::string const& id1,

        std::string& O,

        std::string& U);

    QPDF_DLL

    static void compute_encryption_parameters_V5(

        char const* user_password,

        char const* owner_password,

        int V,

        int R,

        int key_len,

        int P,

        bool encrypt_metadata,

        std::string const& id1,

        std::string& encryption_key,

        std::string& O,

        std::string& U,

        std::string& OE,

        std::string& UE,

        std::string& Perms);

    // Return the full user password as stored in the PDF file.  For files encrypted with 40-bit or

    // 128-bit keys, the user password can be recovered when the file is opened using the owner

    // password.  This is not possible with newer encryption formats. If you are attempting to

    // recover the user password in a user-presentable form, call getTrimmedUserPassword() instead.

    QPDF_DLL

    std::string const& getPaddedUserPassword() const;

    // Return human-readable form of user password subject to same limitations as

    // getPaddedUserPassword().

    QPDF_DLL

    std::string getTrimmedUserPassword() const;

    // Return the previously computed or retrieved encryption key for this file

    QPDF_DLL

    std::string getEncryptionKey() const;

    // Remove security restrictions associated with digitally signed files. From qpdf 11.7.0, this

    // is called by QPDFAcroFormDocumentHelper::disableDigitalSignatures and is more useful when

    // called from there than when just called by itself.

    QPDF_DLL

    void removeSecurityRestrictions();

    // Linearization support

    // Returns true iff the file starts with a linearization parameter dictionary.  Does no

    // additional validation.

    QPDF_DLL

    bool isLinearized();

    // Performs various sanity checks on a linearized file. Return true if no errors or warnings.

    // Otherwise, return false and output errors and warnings to the default output stream

    // (std::cout or whatever is configured in the logger). It is recommended for linearization

    // errors to be treated as warnings.

    QPDF_DLL

    bool checkLinearization();

    // Calls checkLinearization() and, if possible, prints normalized contents of some of the hints

    // tables to the default output stream. Normalization includes adding min values to delta values

    // and adjusting offsets based on the location and size of the primary hint stream.

    QPDF_DLL

    void showLinearizationData();

    // Shows the contents of the cross-reference table

    QPDF_DLL

    void showXRefTable();

    // Starting from qpdf 11.0 user code should not need to call this method. Before 11.0 this

    // method was used to detect all indirect references to objects that don't exist and resolve

    // them by replacing them with null, which is how the PDF spec says to interpret such dangling

    // references. This method is called automatically when you try to add any new objects, if you

    // call getAllObjects, and before a file is written. The qpdf object caches whether it has run

    // this to avoid running it multiple times. Before 11.2.1 you could pass true to force it to run

    // again if you had explicitly added new objects that may have additional dangling references.

    QPDF_DLL

    void fixDanglingReferences(bool force = false);

    // Return the approximate number of indirect objects. It is/ approximate because not all objects

    // in the file are preserved in all cases, and gaps in object numbering are not preserved.

    QPDF_DLL

    size_t getObjectCount();

    // Returns a list of indirect objects for every object in the xref table. Useful for discovering

    // objects that are not otherwise referenced.

    QPDF_DLL

    std::vector<QPDFObjectHandle> getAllObjects();

    // Optimization support -- see doc/optimization.  Implemented in QPDF_optimization.cc

    // The object_stream_data map maps from a "compressed" object to the object stream that contains

    // it. This enables optimize to populate the object <-> user maps with only uncompressed

    // objects. If allow_changes is false, an exception will be thrown if any changes are made

    // during the optimization process. This is available so that the test suite can make sure that

    // a linearized file is already optimized. When called in this way, optimize() still populates

    // the object <-> user maps. The optional skip_stream_parameters parameter, if present, is

    // called for each stream object. The function should return 2 if optimization should discard

    // /Length, /Filter, and /DecodeParms; 1 if it should discard /Length, and 0 if it should

    // preserve all keys. This is used by QPDFWriter to avoid creation of dangling objects for

    // stream dictionary keys it will be regenerating.

    [[deprecated("Unused - see release notes for qpdf 12.1.0")]] QPDF_DLL void optimize(

        std::map<int, int> const& object_stream_data,

        bool allow_changes = true,

        std::function<int(QPDFObjectHandle&)> skip_stream_parameters = nullptr);

    // Traverse page tree return all /Page objects. It also detects and resolves cases in which the

    // same /Page object is duplicated. For efficiency, this method returns a const reference to an

    // internal vector of pages. Calls to addPage, addPageAt, and removePage safely update this, but

    // direct manipulation of the pages tree or pushing inheritable objects to the page level may

    // invalidate it. See comments for updateAllPagesCache() for additional notes. Newer code should

    // use QPDFPageDocumentHelper::getAllPages instead. The decision to expose this internal cache

    // was arguably incorrect, but it is being left here for compatibility. It is, however,

    // completely safe to use this for files that you are not modifying.

    QPDF_DLL

    std::vector<QPDFObjectHandle> const& getAllPages();

    QPDF_DLL

    bool everCalledGetAllPages() const;

    QPDF_DLL

    bool everPushedInheritedAttributesToPages() const;

    // These methods, given a page object or its object/generation number, returns the 0-based index

    // into the array returned by getAllPages() for that page. An exception is thrown if the page is

    // not found.

    QPDF_DLL

    int findPage(QPDFObjGen og);

    QPDF_DLL

    int findPage(QPDFObjectHandle& page);

    // This method synchronizes QPDF's cache of the page structure with the actual /Pages tree.  If

    // you restrict changes to the /Pages tree, including addition, removal, or replacement of pages

    // or changes to any /Pages objects, to calls to these page handling APIs, you never need to

    // call this method.  If you modify /Pages structures directly, you must call this method

    // afterwards.  This method updates the internal list of pages, so after calling this method,

    // any previous references returned by getAllPages() will be valid again.  It also resets any

    // state about having pushed inherited attributes in /Pages objects down to the pages, so if you

    // add any inheritable attributes to a /Pages object, you should also call this method.

    QPDF_DLL

    void updateAllPagesCache();

    // Legacy handling API. These methods are not going anywhere, and you should feel free to

    // continue using them if it simplifies your code. Newer code should make use of

    // QPDFPageDocumentHelper instead as future page handling methods will be added there. The

    // functionality and specification of these legacy methods is identical to the identically named

    // methods there, except that these versions use QPDFObjectHandle instead of

    // QPDFPageObjectHelper, so please see comments in that file for descriptions. There are

    // subtleties you need to know about, so please look at the comments there.

    QPDF_DLL

    void pushInheritedAttributesToPage();

    QPDF_DLL

    void addPage(QPDFObjectHandle newpage, bool first);

    QPDF_DLL

    void addPageAt(QPDFObjectHandle newpage, bool before, QPDFObjectHandle refpage);

    QPDF_DLL

    void removePage(QPDFObjectHandle page);

    // End legacy page helpers

    // End of the public API. The following classes and methods are for qpdf internal use only.

    class Doc;

    inline Doc& doc();

    // For testing only -- do not add to DLL

    static bool test_json_validators();

  private:

    // It has never been safe to copy QPDF objects as there is code in the library that assumes

    // there are no copies of a QPDF object. Copying QPDF objects was not prevented by the API until

    // qpdf 11. If you have been copying QPDF objects, use std::shared_ptr<QPDF> instead. From qpdf

    // 11, you can use QPDF::create to create them.

    QPDF(QPDF const&) = delete;

    QPDF& operator=(QPDF const&) = delete;

    static std::string const qpdf_version;

    class ObjCache;

    class EncryptionParameters;

    class StringDecrypter;

    class ResolveRecorder;

    class JSONReactor;

    void removeObject(QPDFObjGen og);

    // Calls finish() on the pipeline when done but does not delete it

    bool pipeStreamData(

        QPDFObjGen og,

        qpdf_offset_t offset,

        size_t length,

        QPDFObjectHandle dict,

        bool is_root_metadata,

        Pipeline* pipeline,

        bool suppress_warnings,

        bool will_retry);

    static bool pipeStreamData(

        std::shared_ptr<QPDF::EncryptionParameters> encp,

        std::shared_ptr<InputSource> file,

        QPDF& qpdf_for_warning,

        QPDFObjGen og,

        qpdf_offset_t offset,

        size_t length,

        QPDFObjectHandle dict,

        bool is_root_metadata,

        Pipeline* pipeline,

        bool suppress_warnings,

        bool will_retry);

    // methods to support encryption -- implemented in QPDF_encryption.cc

    void initializeEncryption();

    static std::string

    getKeyForObject(std::shared_ptr<EncryptionParameters> encp, QPDFObjGen og, bool use_aes);

    void decryptString(std::string&, QPDFObjGen og);

    static void decryptStream(

        std::shared_ptr<EncryptionParameters> encp,

        std::shared_ptr<InputSource> file,

        QPDF& qpdf_for_warning,

        Pipeline*& pipeline,

        QPDFObjGen og,

        QPDFObjectHandle& stream_dict,

        bool is_root_metadata,

        std::unique_ptr<Pipeline>& heap);

    // JSON import

    void importJSON(std::shared_ptr<InputSource>, bool must_be_complete);

    class Members;

    // Keep all member variables inside the Members object, which we dynamically allocate. This

    // makes it possible to add new private members without breaking binary compatibility.

    std::unique_ptr<Members> m;

};

#endif // QPDF_HH