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pdfio/pdfio-file.c
Michael R Sweet 61a7964d90 Implement pdfioFileSetPermissions.
2021-10-10 22:27:09 -04:00

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//
// PDF file functions for PDFio.
//
// Copyright © 2021 by Michael R Sweet.
//
// Licensed under Apache License v2.0. See the file "LICENSE" for more
// information.
//
//
// Include necessary headers...
//
#include "pdfio-private.h"
#ifndef O_BINARY
# define O_BINARY 0
#endif // !O_BINARY
//
// Local functions...
//
static pdfio_obj_t *add_obj(pdfio_file_t *pdf, size_t number, unsigned short generation, off_t offset);
static int compare_objmaps(_pdfio_objmap_t *a, _pdfio_objmap_t *b);
static int compare_objs(pdfio_obj_t **a, pdfio_obj_t **b);
static bool load_obj_stream(pdfio_obj_t *obj);
static bool load_pages(pdfio_file_t *pdf, pdfio_obj_t *obj);
static bool load_xref(pdfio_file_t *pdf, off_t xref_offset);
static bool write_catalog(pdfio_file_t *pdf);
static bool write_pages(pdfio_file_t *pdf);
static bool write_trailer(pdfio_file_t *pdf);
//
// '_pdfioFileAddMappedObj()' - Add a mapped object.
//
bool // O - `true` on success, `false` on failure
_pdfioFileAddMappedObj(
pdfio_file_t *pdf, // I - Destination PDF file
pdfio_obj_t *dst_obj, // I - Destination object
pdfio_obj_t *src_obj) // I - Source object
{
_pdfio_objmap_t *map; // Object map
// Allocate memory as needed...
if (pdf->num_objmaps >= pdf->alloc_objmaps)
{
if ((map = realloc(pdf->objmaps, (pdf->alloc_objmaps + 16) * sizeof(_pdfio_objmap_t))) == NULL)
{
_pdfioFileError(pdf, "Unable to allocate memory for object map.");
return (false);
}
pdf->alloc_objmaps += 16;
pdf->objmaps = map;
}
// Add an object to the end...
map = pdf->objmaps + pdf->num_objmaps;
pdf->num_objmaps ++;
map->obj = dst_obj;
map->src_pdf = src_obj->pdf;
map->src_number = src_obj->number;
// Sort as needed...
if (pdf->num_objmaps > 1 && compare_objmaps(map, pdf->objmaps + pdf->num_objmaps - 2) < 0)
qsort(pdf->objmaps, pdf->num_objmaps, sizeof(_pdfio_objmap_t), (int (*)(const void *, const void *))compare_objmaps);
return (true);
}
//
// '_pdfioFileAddPage()' - Add a page to a PDF file.
//
bool // O - `true` on success and `false` on failure
_pdfioFileAddPage(pdfio_file_t *pdf, // I - PDF file
pdfio_obj_t *obj) // I - Page object
{
// Add the page to the array of pages...
if (pdf->num_pages >= pdf->alloc_pages)
{
pdfio_obj_t **temp = (pdfio_obj_t **)realloc(pdf->pages, (pdf->alloc_pages + 16) * sizeof(pdfio_obj_t *));
if (!temp)
{
_pdfioFileError(pdf, "Unable to allocate memory for pages.");
return (false);
}
pdf->alloc_pages += 16;
pdf->pages = temp;
}
pdf->pages[pdf->num_pages ++] = obj;
return (true);
}
//
// 'pdfioFileClose()' - Close a PDF file and free all memory used for it.
//
bool // O - `true` on success and `false` on failure
pdfioFileClose(pdfio_file_t *pdf) // I - PDF file
{
bool ret = true; // Return value
size_t i; // Looping var
// Range check input
if (!pdf)
return (false);
// Close the file itself...
if (pdf->mode == _PDFIO_MODE_WRITE)
{
ret = false;
if (pdfioObjClose(pdf->info))
if (write_pages(pdf))
if (write_catalog(pdf))
if (write_trailer(pdf))
ret = _pdfioFileFlush(pdf);
}
if (pdf->fd >= 0 && close(pdf->fd) < 0)
ret = false;
// Free all data...
free(pdf->filename);
free(pdf->version);
for (i = 0; i < pdf->num_arrays; i ++)
_pdfioArrayDelete(pdf->arrays[i]);
free(pdf->arrays);
for (i = 0; i < pdf->num_dicts; i ++)
_pdfioDictDelete(pdf->dicts[i]);
free(pdf->dicts);
for (i = 0; i < pdf->num_objs; i ++)
_pdfioObjDelete(pdf->objs[i]);
free(pdf->objs);
free(pdf->objmaps);
free(pdf->pages);
for (i = 0; i < pdf->num_strings; i ++)
free(pdf->strings[i]);
free(pdf->strings);
free(pdf);
return (ret);
}
//
// 'pdfioFileCreate()' - Create a PDF file.
//
// This function creates a new PDF file. The "filename" argument specifies the
// name of the PDF file to create.
//
// The "version" argument specifies the PDF version number for the file or
// `NULL` for the default ("2.0").
//
// The "media_box" and "crop_box" arguments specify the default MediaBox and
// CropBox for pages in the PDF file - if `NULL` then a default "Universal" size
// of 8.27x11in (the intersection of US Letter and ISO A4) is used.
//
// The "error_cb" and "error_data" arguments specify an error handler callback
// and its data pointer - if `NULL` the default error handler is used that
// writes error messages to `stderr`.
//
pdfio_file_t * // O - PDF file or `NULL` on error
pdfioFileCreate(
const char *filename, // I - Filename
const char *version, // I - PDF version number or `NULL` for default (2.0)
pdfio_rect_t *media_box, // I - Default MediaBox for pages
pdfio_rect_t *crop_box, // I - Default CropBox for pages
pdfio_error_cb_t error_cb, // I - Error callback or `NULL` for default
void *error_data) // I - Error callback data, if any
{
pdfio_file_t *pdf; // PDF file
pdfio_dict_t *dict; // Dictionary for pages object
pdfio_dict_t *info_dict; // Dictionary for information object
// Range check input...
if (!filename)
return (NULL);
if (!version)
version = "2.0";
if (!error_cb)
{
error_cb = _pdfioFileDefaultError;
error_data = NULL;
}
// Allocate a PDF file structure...
if ((pdf = (pdfio_file_t *)calloc(1, sizeof(pdfio_file_t))) == NULL)
{
pdfio_file_t temp; // Dummy file
char message[8192]; // Message string
temp.filename = (char *)filename;
snprintf(message, sizeof(message), "Unable to allocate memory for PDF file - %s", strerror(errno));
(error_cb)(&temp, message, error_data);
return (NULL);
}
pdf->filename = strdup(filename);
pdf->version = strdup(version);
pdf->mode = _PDFIO_MODE_WRITE;
pdf->error_cb = error_cb;
pdf->error_data = error_data;
pdf->bufptr = pdf->buffer;
pdf->bufend = pdf->buffer + sizeof(pdf->buffer);
if (media_box)
{
pdf->media_box = *media_box;
}
else
{
// Default to "universal" size (intersection of A4 and US Letter)
pdf->media_box.x2 = 210.0 * 72.0f / 25.4f;
pdf->media_box.y2 = 11.0f * 72.0f;
}
if (crop_box)
{
pdf->crop_box = *crop_box;
}
else
{
// Default to "universal" size (intersection of A4 and US Letter)
pdf->crop_box.x2 = 210.0 * 72.0f / 25.4f;
pdf->crop_box.y2 = 11.0f * 72.0f;
}
// Create the file...
if ((pdf->fd = open(filename, O_WRONLY | O_BINARY | O_CREAT | O_TRUNC, 0666)) < 0)
{
_pdfioFileError(pdf, "Unable to create file - %s", strerror(errno));
free(pdf->filename);
free(pdf->version);
free(pdf);
return (NULL);
}
// Write a standard PDF header...
if (!_pdfioFilePrintf(pdf, "%%PDF-%s\n%%\342\343\317\323\n", version))
{
pdfioFileClose(pdf);
unlink(filename);
return (NULL);
}
// Create the pages object...
if ((dict = pdfioDictCreate(pdf)) == NULL)
{
pdfioFileClose(pdf);
unlink(filename);
return (NULL);
}
pdfioDictSetName(dict, "Type", "Pages");
if ((pdf->pages_root = pdfioFileCreateObj(pdf, dict)) == NULL)
{
pdfioFileClose(pdf);
unlink(filename);
return (NULL);
}
// Create the info object...
if ((info_dict = pdfioDictCreate(pdf)) == NULL)
{
pdfioFileClose(pdf);
unlink(filename);
return (NULL);
}
pdfioDictSetDate(info_dict, "CreationDate", time(NULL));
pdfioDictSetString(info_dict, "Producer", "pdfio/" PDFIO_VERSION);
if ((pdf->info = pdfioFileCreateObj(pdf, info_dict)) == NULL)
{
pdfioFileClose(pdf);
unlink(filename);
return (NULL);
}
return (pdf);
}
//
// 'pdfioFileCreateArrayObj()' - Create a new object in a PDF file containing an array.
//
// This function creates a new object with an array value in a PDF file.
// You must call @link pdfioObjClose@ to write the object to the file.
//
pdfio_obj_t * // O - New object
pdfioFileCreateArrayObj(
pdfio_file_t *pdf, // I - PDF file
pdfio_array_t *array) // I - Object array
{
_pdfio_value_t value; // Object value
// Range check input...
if (!pdf || !array)
return (NULL);
value.type = PDFIO_VALTYPE_ARRAY;
value.value.array = array;
return (_pdfioFileCreateObj(pdf, array->pdf, &value));
}
//
// 'pdfioFileCreateObj()' - Create a new object in a PDF file.
//
pdfio_obj_t * // O - New object
pdfioFileCreateObj(
pdfio_file_t *pdf, // I - PDF file
pdfio_dict_t *dict) // I - Object dictionary
{
_pdfio_value_t value; // Object value
// Range check input...
if (!pdf || !dict)
return (NULL);
value.type = PDFIO_VALTYPE_DICT;
value.value.dict = dict;
return (_pdfioFileCreateObj(pdf, dict->pdf, &value));
}
//
// '_pdfioFileCreateObj()' - Create a new object in a PDF file with a value.
//
pdfio_obj_t * // O - New object
_pdfioFileCreateObj(
pdfio_file_t *pdf, // I - PDF file
pdfio_file_t *srcpdf, // I - Source PDF file, if any
_pdfio_value_t *value) // I - Object dictionary
{
pdfio_obj_t *obj; // New object
// Range check input...
if (!pdf)
return (NULL);
if (pdf->mode != _PDFIO_MODE_WRITE)
return (NULL);
// Allocate memory for the object...
if ((obj = (pdfio_obj_t *)calloc(1, sizeof(pdfio_obj_t))) == NULL)
{
_pdfioFileError(pdf, "Unable to allocate memory for object - %s", strerror(errno));
return (NULL);
}
// Expand the objects array as needed
if (pdf->num_objs >= pdf->alloc_objs)
{
pdfio_obj_t **temp = (pdfio_obj_t **)realloc(pdf->objs, (pdf->alloc_objs + 32) * sizeof(pdfio_obj_t *));
if (!temp)
{
_pdfioFileError(pdf, "Unable to allocate memory for object - %s", strerror(errno));
free(obj);
return (NULL);
}
pdf->objs = temp;
pdf->alloc_objs += 32;
}
pdf->objs[pdf->num_objs ++] = obj;
// Initialize the object...
obj->pdf = pdf;
obj->number = pdf->num_objs;
if (value)
_pdfioValueCopy(pdf, &obj->value, srcpdf, value);
// Don't write anything just yet...
return (obj);
}
//
// 'pdfioFileCreateOutput()' - Create a PDF file through an output callback.
//
// This function creates a new PDF file that is streamed though an output
// callback. The "output_cb" and "output_ctx" arguments specify the output
// callback and its context pointer which is called whenever data needs to be
// written:
//
// ```
// ssize_t
// output_cb(void *output_ctx, const void *buffer, size_t bytes)
// {
// // Write buffer to output and return the number of bytes written
// }
// ```
//
// The "version" argument specifies the PDF version number for the file or
// `NULL` for the default ("2.0").
//
// The "media_box" and "crop_box" arguments specify the default MediaBox and
// CropBox for pages in the PDF file - if `NULL` then a default "Universal" size
// of 8.27x11in (the intersection of US Letter and ISO A4) is used.
//
// The "error_cb" and "error_data" arguments specify an error handler callback
// and its data pointer - if `NULL` the default error handler is used that
// writes error messages to `stderr`.
//
// > *Note*: Files created using this API are slightly larger than those
// > created using the @link pdfioFileCreate@ function since stream lengths are
// > stored as indirect object references.
//
pdfio_file_t * // O - PDF file or `NULL` on error
pdfioFileCreateOutput(
pdfio_output_cb_t output_cb, // I - Output callback
void *output_ctx, // I - Output context
const char *version, // I - PDF version number or `NULL` for default (2.0)
pdfio_rect_t *media_box, // I - Default MediaBox for pages
pdfio_rect_t *crop_box, // I - Default CropBox for pages
pdfio_error_cb_t error_cb, // I - Error callback or `NULL` for default
void *error_data) // I - Error callback data, if any
{
pdfio_file_t *pdf; // PDF file
pdfio_dict_t *dict; // Dictionary for pages object
pdfio_dict_t *info_dict; // Dictionary for information object
// Range check input...
if (!output_cb)
return (NULL);
if (!version)
version = "2.0";
if (!error_cb)
{
error_cb = _pdfioFileDefaultError;
error_data = NULL;
}
// Allocate a PDF file structure...
if ((pdf = (pdfio_file_t *)calloc(1, sizeof(pdfio_file_t))) == NULL)
{
pdfio_file_t temp; // Dummy file
char message[8192]; // Message string
temp.filename = (char *)"output.pdf";
snprintf(message, sizeof(message), "Unable to allocate memory for PDF file - %s", strerror(errno));
(error_cb)(&temp, message, error_data);
return (NULL);
}
pdf->filename = strdup("output.pdf");
pdf->version = strdup(version);
pdf->mode = _PDFIO_MODE_WRITE;
pdf->error_cb = error_cb;
pdf->error_data = error_data;
pdf->bufptr = pdf->buffer;
pdf->bufend = pdf->buffer + sizeof(pdf->buffer);
if (media_box)
{
pdf->media_box = *media_box;
}
else
{
// Default to "universal" size (intersection of A4 and US Letter)
pdf->media_box.x2 = 210.0 * 72.0f / 25.4f;
pdf->media_box.y2 = 11.0f * 72.0f;
}
if (crop_box)
{
pdf->crop_box = *crop_box;
}
else
{
// Default to "universal" size (intersection of A4 and US Letter)
pdf->crop_box.x2 = 210.0 * 72.0f / 25.4f;
pdf->crop_box.y2 = 11.0f * 72.0f;
}
// Save output callback...
pdf->fd = -1;
pdf->output_cb = output_cb;
pdf->output_ctx = output_ctx;
// Write a standard PDF header...
if (!_pdfioFilePrintf(pdf, "%%PDF-%s\n%%\342\343\317\323\n", version))
{
pdfioFileClose(pdf);
return (NULL);
}
// Create the pages object...
if ((dict = pdfioDictCreate(pdf)) == NULL)
{
pdfioFileClose(pdf);
return (NULL);
}
pdfioDictSetName(dict, "Type", "Pages");
if ((pdf->pages_root = pdfioFileCreateObj(pdf, dict)) == NULL)
{
pdfioFileClose(pdf);
return (NULL);
}
// Create the info object...
if ((info_dict = pdfioDictCreate(pdf)) == NULL)
{
pdfioFileClose(pdf);
return (NULL);
}
pdfioDictSetDate(info_dict, "CreationDate", time(NULL));
pdfioDictSetString(info_dict, "Producer", "pdfio/" PDFIO_VERSION);
if ((pdf->info = pdfioFileCreateObj(pdf, info_dict)) == NULL)
{
pdfioFileClose(pdf);
return (NULL);
}
return (pdf);
}
//
// 'pdfioFileCreatePage()' - Create a page in a PDF file.
//
pdfio_stream_t * // O - Contents stream
pdfioFileCreatePage(pdfio_file_t *pdf, // I - PDF file
pdfio_dict_t *dict) // I - Page dictionary
{
pdfio_obj_t *page, // Page object
*contents; // Contents object
pdfio_dict_t *contents_dict; // Dictionary for Contents object
// Range check input...
if (!pdf)
return (NULL);
// Copy the page dictionary...
if (dict)
dict = pdfioDictCopy(pdf, dict);
else
dict = pdfioDictCreate(pdf);
if (!dict)
return (NULL);
// Make sure the page dictionary has all of the required keys...
if (!_pdfioDictGetValue(dict, "CropBox"))
pdfioDictSetRect(dict, "CropBox", &pdf->crop_box);
if (!_pdfioDictGetValue(dict, "MediaBox"))
pdfioDictSetRect(dict, "MediaBox", &pdf->media_box);
pdfioDictSetObj(dict, "Parent", pdf->pages_root);
if (!_pdfioDictGetValue(dict, "Resources"))
pdfioDictSetDict(dict, "Resources", pdfioDictCreate(pdf));
if (!_pdfioDictGetValue(dict, "Type"))
pdfioDictSetName(dict, "Type", "Page");
// Create the page object...
if ((page = pdfioFileCreateObj(pdf, dict)) == NULL)
return (NULL);
// Create a contents object to hold the contents of the page...
if ((contents_dict = pdfioDictCreate(pdf)) == NULL)
return (NULL);
#ifndef DEBUG
pdfioDictSetName(contents_dict, "Filter", "FlateDecode");
#endif // !DEBUG
if ((contents = pdfioFileCreateObj(pdf, contents_dict)) == NULL)
return (NULL);
// Add the contents stream to the pages object and write it...
pdfioDictSetObj(dict, "Contents", contents);
if (!pdfioObjClose(page))
return (NULL);
if (!_pdfioFileAddPage(pdf, page))
return (NULL);
// Create the contents stream...
#ifdef DEBUG
return (pdfioObjCreateStream(contents, PDFIO_FILTER_NONE));
#else
return (pdfioObjCreateStream(contents, PDFIO_FILTER_FLATE));
#endif // DEBUG
}
//
// '_pdfioFileFindMappedObj()' - Find a mapped object.
//
pdfio_obj_t * // O - Match object or `NULL` if none
_pdfioFileFindMappedObj(
pdfio_file_t *pdf, // I - Destination PDF file
pdfio_file_t *src_pdf, // I - Source PDF file
size_t src_number) // I - Source object number
{
_pdfio_objmap_t key, // Search key
*match; // Matching object map
// If we have no mapped objects, return NULL immediately...
if (pdf->num_objmaps == 0)
return (NULL);
// Otherwise search for a match...
key.src_pdf = src_pdf;
key.src_number = src_number;
if ((match = (_pdfio_objmap_t *)bsearch(&key, pdf->objmaps, pdf->num_objmaps, sizeof(_pdfio_objmap_t), (int (*)(const void *, const void *))compare_objmaps)) != NULL)
return (match->obj);
else
return (NULL);
}
//
// 'pdfioFileFindObj()' - Find an object using its object number.
//
// This differs from @link pdfioFileGetObj@ which takes an index into the
// list of objects while this function takes the object number.
//
pdfio_obj_t * // O - Object or `NULL` if not found
pdfioFileFindObj(
pdfio_file_t *pdf, // I - PDF file
size_t number) // I - Object number (1 to N)
{
pdfio_obj_t key, // Search key
*keyptr, // Pointer to key
**match; // Pointer to match
if (pdf->num_objs > 0)
{
key.number = number;
keyptr = &key;
match = (pdfio_obj_t **)bsearch(&keyptr, pdf->objs, pdf->num_objs, sizeof(pdfio_obj_t *), (int (*)(const void *, const void *))compare_objs);
return (match ? *match : NULL);
}
return (NULL);
}
//
// 'pdfioFileGetAuthor()' - Get the author for a PDF file.
//
const char * // O - Author or `NULL` for none
pdfioFileGetAuthor(pdfio_file_t *pdf) // I - PDF file
{
return (pdf && pdf->info ? pdfioDictGetString(pdf->info->value.value.dict, "Author") : NULL);
}
//
// 'pdfioFileGetCreationDate()' - Get the creation date for a PDF file.
//
time_t // O - Creation date or `0` for none
pdfioFileGetCreationDate(
pdfio_file_t *pdf) // I - PDF file
{
return (pdf && pdf->info ? pdfioDictGetDate(pdf->info->value.value.dict, "CreationDate") : 0);
}
//
// 'pdfioFileGetCreator()' - Get the creator string for a PDF file.
//
const char * // O - Creator string or `NULL` for none
pdfioFileGetCreator(pdfio_file_t *pdf) // I - PDF file
{
return (pdf && pdf->info ? pdfioDictGetString(pdf->info->value.value.dict, "Creator") : NULL);
}
//
// 'pdfioFileGetID()' - Get the PDF file's ID strings.
//
pdfio_array_t * // O - Array with binary strings
pdfioFileGetID(pdfio_file_t *pdf) // I - PDF file
{
return (pdf && pdf->info ? pdfioDictGetArray(pdf->trailer, "ID") : NULL);
}
//
// 'pdfioFileGetKeywords()' - Get the keywords for a PDF file.
//
const char * // O - Keywords string or `NULL` for none
pdfioFileGetKeywords(pdfio_file_t *pdf) // I - PDF file
{
return (pdf && pdf->info ? pdfioDictGetString(pdf->info->value.value.dict, "Keywords") : NULL);
}
//
// 'pdfioFileGetName()' - Get a PDF's filename.
//
const char * // O - Filename
pdfioFileGetName(pdfio_file_t *pdf) // I - PDF file
{
return (pdf ? pdf->filename : NULL);
}
//
// 'pdfioFileGetNumObjs()' - Get the number of objects in a PDF file.
//
size_t // O - Number of objects
pdfioFileGetNumObjs(
pdfio_file_t *pdf) // I - PDF file
{
return (pdf ? pdf->num_objs : 0);
}
//
// 'pdfioFileGetNumPages()' - Get the number of pages in a PDF file.
//
size_t // O - Number of pages
pdfioFileGetNumPages(pdfio_file_t *pdf) // I - PDF file
{
return (pdf ? pdf->num_pages : 0);
}
//
// 'pdfioFileGetObj()' - Get an object from a PDF file.
//
pdfio_obj_t * // O - Object
pdfioFileGetObj(pdfio_file_t *pdf, // I - PDF file
size_t n) // I - Object index (starting at 0)
{
if (!pdf || n >= pdf->num_objs)
return (NULL);
else
return (pdf->objs[n]);
}
//
// 'pdfioFileGetPage()' - Get a page object from a PDF file.
//
pdfio_obj_t * // O - Object
pdfioFileGetPage(pdfio_file_t *pdf, // I - PDF file
size_t n) // I - Page index (starting at 0)
{
if (!pdf || n >= pdf->num_pages)
return (NULL);
else
return (pdf->pages[n]);
}
//
// 'pdfioFileGetProducer()' - Get the producer string for a PDF file.
//
const char * // O - Producer string or `NULL` for none
pdfioFileGetProducer(pdfio_file_t *pdf) // I - PDF file
{
return (pdf && pdf->info ? pdfioDictGetString(pdf->info->value.value.dict, "Producer") : NULL);
}
//
// 'pdfioFileGetSubject()' - Get the subject for a PDF file.
//
const char * // O - Subject or `NULL` for none
pdfioFileGetSubject(pdfio_file_t *pdf) // I - PDF file
{
return (pdf && pdf->info ? pdfioDictGetString(pdf->info->value.value.dict, "Subject") : NULL);
}
//
// 'pdfioFileGetTitle()' - Get the title for a PDF file.
//
const char * // O - Title or `NULL` for none
pdfioFileGetTitle(pdfio_file_t *pdf) // I - PDF file
{
return (pdf && pdf->info ? pdfioDictGetString(pdf->info->value.value.dict, "Title") : NULL);
}
//
// 'pdfioFileGetVersion()' - Get the PDF version number for a PDF file.
//
const char * // O - Version number or `NULL`
pdfioFileGetVersion(
pdfio_file_t *pdf) // I - PDF file
{
return (pdf ? pdf->version : NULL);
}
//
// 'pdfioFileOpen()' - Open a PDF file for reading.
//
// This function opens an existing PDF file. The "filename" argument specifies
// the name of the PDF file to create.
//
// The "password_cb" and "password_data" arguments specify a password callback
// and its data pointer for PDF files that use one of the standard Adobe
// "security" handlers. The callback returns a password string or `NULL` to
// cancel the open. If `NULL` is specified for the callback function and the
// PDF file requires a password, the open will always fail.
//
// The "error_cb" and "error_data" arguments specify an error handler callback
// and its data pointer - if `NULL` the default error handler is used that
// writes error messages to `stderr`.
//
pdfio_file_t * // O - PDF file
pdfioFileOpen(
const char *filename, // I - Filename
pdfio_password_cb_t password_cb, // I - Password callback or `NULL` for none
void *password_data, // I - Password callback data, if any
pdfio_error_cb_t error_cb, // I - Error callback or `NULL` for default
void *error_data) // I - Error callback data, if any
{
pdfio_file_t *pdf; // PDF file
char line[1024], // Line from file
*ptr; // Pointer into line
off_t xref_offset; // Offset to xref table
(void)password_cb;
(void)password_data;
// Range check input...
if (!filename)
return (NULL);
if (!error_cb)
{
error_cb = _pdfioFileDefaultError;
error_data = NULL;
}
// Allocate a PDF file structure...
if ((pdf = (pdfio_file_t *)calloc(1, sizeof(pdfio_file_t))) == NULL)
{
pdfio_file_t temp; // Dummy file
char message[8192]; // Message string
temp.filename = (char *)filename;
snprintf(message, sizeof(message), "Unable to allocate memory for PDF file - %s", strerror(errno));
(error_cb)(&temp, message, error_data);
return (NULL);
}
pdf->filename = strdup(filename);
pdf->mode = _PDFIO_MODE_READ;
pdf->error_cb = error_cb;
pdf->error_data = error_data;
// Open the file...
if ((pdf->fd = open(filename, O_RDONLY | O_BINARY)) < 0)
{
_pdfioFileError(pdf, "Unable to open file - %s", strerror(errno));
free(pdf->filename);
free(pdf);
return (NULL);
}
// Read the header from the first line...
if (!_pdfioFileGets(pdf, line, sizeof(line)))
goto error;
if ((strncmp(line, "%PDF-1.", 7) && strncmp(line, "%PDF-2.", 7)) || !isdigit(line[7] & 255))
{
// Bad header
_pdfioFileError(pdf, "Bad header '%s'.", line);
goto error;
}
// Copy the version number...
pdf->version = strdup(line + 5);
// Grab the last 32 characters of the file to find the start of the xref table...
if (_pdfioFileSeek(pdf, -32, SEEK_END) < 0)
{
_pdfioFileError(pdf, "Unable to read startxref data.");
goto error;
}
if (_pdfioFileRead(pdf, line, 32) < 32)
{
_pdfioFileError(pdf, "Unable to read startxref data.");
goto error;
}
line[32] = '\0';
if ((ptr = strstr(line, "startxref")) == NULL)
{
_pdfioFileError(pdf, "Unable to find start of xref table.");
goto error;
}
xref_offset = (off_t)strtol(ptr + 9, NULL, 10);
if (!load_xref(pdf, xref_offset))
goto error;
return (pdf);
// If we get here we had a fatal read error...
error:
pdfioFileClose(pdf);
return (NULL);
}
//
// 'pdfioFileSetAuthor()' - Set the author for a PDF file.
//
void
pdfioFileSetAuthor(pdfio_file_t *pdf, // I - PDF file
const char *value) // I - Value
{
if (pdf && pdf->info)
pdfioDictSetString(pdf->info->value.value.dict, "Author", pdfioStringCreate(pdf, value));
}
//
// 'pdfioFileSetCreationDate()' - Set the creation date for a PDF file.
//
void
pdfioFileSetCreationDate(
pdfio_file_t *pdf, // I - PDF file
time_t value) // I - Value
{
if (pdf && pdf->info)
pdfioDictSetDate(pdf->info->value.value.dict, "CreationDate", value);
}
//
// 'pdfioFileSetCreator()' - Set the creator string for a PDF file.
//
void
pdfioFileSetCreator(pdfio_file_t *pdf, // I - PDF file
const char *value)// I - Value
{
if (pdf && pdf->info)
pdfioDictSetString(pdf->info->value.value.dict, "Creator", pdfioStringCreate(pdf, value));
}
//
// 'pdfioFileSetKeywords()' - Set the keywords string for a PDF file.
//
void
pdfioFileSetKeywords(
pdfio_file_t *pdf, // I - PDF file
const char *value) // I - Value
{
if (pdf && pdf->info)
pdfioDictSetString(pdf->info->value.value.dict, "Keywords", pdfioStringCreate(pdf, value));
}
//
// 'pdfioFileSetPermissions()' - Set the PDF permissions, encryption mode, and passwords.
//
// This function sets the PDF usage permissions, encryption mode, and
// passwords.
//
// > *Note*: This function must be called before creating or copying any
// > objects. Due to fundamental limitations in the PDF format, PDF encryption
// > offers little protection from disclosure. Permissions are not enforced in
// > any meaningful way.
//
bool // O - `true` on success, `false` otherwise
pdfioFileSetPermissions(
pdfio_file_t *pdf, // I - PDF file
pdfio_permission_t permissions, // I - Use permissions
pdfio_encryption_t encryption, // I - Type of encryption to use
const char *owner_password, // I - Owner password, if any
const char *user_password) // I - User password, if any
{
pdfio_dict_t *dict; // Encryption dictionary
size_t i, j; // Looping vars
_pdfio_md5_t md5; // MD5 context
uint8_t digest[16]; // 128-bit MD5 digest
_pdfio_rc4_t rc4; // RC4 encryption context
size_t len; // Length of password
uint8_t owner_pad[32], // Padded owner password
user_pad[32], // Padded user password
perm_bytes[4], // Permissions bytes
*file_id; // File ID bytes
size_t file_id_len; // Length of file ID
static uint8_t pad[32] = // Padding for passwords
{
0x28, 0xbf, 0x4e, 0x5e, 0x4e, 0x75, 0x8a, 0x41,
0x64, 0x00, 0x4e, 0x56, 0xff, 0xfa, 0x01, 0x08,
0x2e, 0x2e, 0x00, 0xb6, 0xd0, 0x68, 0x3e, 0x80,
0x2f, 0x0c, 0xa9, 0xfe, 0x64, 0x53, 0x69, 0x7a
};
if (!pdf)
return (false);
if (pdf->num_objs > 0)
{
_pdfioFileError(pdf, "You must call pdfioFileSetPermissions before adding any objects.");
return (false);
}
if (encryption == PDFIO_ENCRYPTION_NONE)
return (true);
if ((dict = pdfioDictCreate(pdf)) == NULL)
{
_pdfioFileError(pdf, "Unable to create encryption dictionary.");
return (false);
}
pdfioDictSetName(dict, "Filter", "Standard");
switch (encryption)
{
case PDFIO_ENCRYPTION_RC4_128 :
case PDFIO_ENCRYPTION_AES_128 :
// Create the 128-bit encryption keys...
if (user_password)
{
// Copy the user password and pad it with the special PDF pad bytes
if ((len = strlen(user_password)) > sizeof(user_pad))
len = sizeof(user_pad);
if (len > 0)
memcpy(user_pad, user_password, len);
if (len < sizeof(user_pad))
memcpy(user_pad + len, pad, sizeof(user_pad) - len);
}
else
{
// Use default (pad) password
memcpy(user_pad, pad, sizeof(user_pad));
}
if (owner_password && *owner_password)
{
// Copy the owner password and pad it with the special PDF pad bytes
if ((len = strlen(owner_password)) > sizeof(owner_pad))
len = sizeof(owner_pad);
if (len > 0)
memcpy(owner_pad, owner_password, len);
if (len < sizeof(owner_pad))
memcpy(owner_pad + len, pad, sizeof(owner_pad) - len);
}
else
{
// Generate a random owner password...
_pdfioCryptoMakeRandom(owner_pad, sizeof(owner_pad));
}
// Compute the owner key...
_pdfioCryptoMD5Init(&md5);
_pdfioCryptoMD5Append(&md5, owner_pad, 32);
_pdfioCryptoMD5Finish(&md5, digest);
// MD5 the result 50 more times...
for (i = 0; i < 50; i ++)
{
_pdfioCryptoMD5Init(&md5);
_pdfioCryptoMD5Append(&md5, digest, 16);
_pdfioCryptoMD5Finish(&md5, digest);
}
// Copy the padded user password...
memcpy(pdf->owner_key, user_pad, sizeof(pdf->owner_key));
// Encrypt the result 20 times...
for (i = 0; i < 20; i ++)
{
uint8_t encrypt_key[16];// RC4 encryption key
// XOR each byte in the digest with the loop counter to make a key...
for (j = 0; j < sizeof(encrypt_key); j ++)
encrypt_key[j] = (uint8_t)(digest[j] ^ i);
_pdfioCryptoRC4Init(&rc4, encrypt_key, sizeof(encrypt_key));
_pdfioCryptoRC4Crypt(&rc4, pdf->owner_key, sizeof(pdf->owner_key));
}
// Generate the encryption key
perm_bytes[0] = (uint8_t)permissions;
perm_bytes[1] = (uint8_t)(permissions >> 8);
perm_bytes[2] = (uint8_t)(permissions >> 16);
perm_bytes[3] = (uint8_t)(permissions >> 24);
file_id = pdfioArrayGetBinary(pdf->id_array, 0, &file_id_len);
_pdfioCryptoMD5Init(&md5);
_pdfioCryptoMD5Append(&md5, user_pad, 32);
_pdfioCryptoMD5Append(&md5, pdf->owner_key, 32);
_pdfioCryptoMD5Append(&md5, perm_bytes, 4);
_pdfioCryptoMD5Append(&md5, file_id, file_id_len);
_pdfioCryptoMD5Finish(&md5, digest);
// MD5 the result 50 times..
for (i = 0; i < 50; i ++)
{
_pdfioCryptoMD5Init(&md5);
_pdfioCryptoMD5Append(&md5, digest, 16);
_pdfioCryptoMD5Finish(&md5, digest);
}
memcpy(pdf->encryption_key, digest, 16);
// Generate the user key...
_pdfioCryptoMD5Init(&md5);
_pdfioCryptoMD5Append(&md5, pad, 32);
_pdfioCryptoMD5Append(&md5, file_id, file_id_len);
_pdfioCryptoMD5Finish(&md5, pdf->user_key);
memset(pdf->user_key + 16, 0, 16);
// Encrypt the result 20 times...
for (i = 0; i < 20; i ++)
{
// XOR each byte in the key with the loop counter...
for (j = 0; j < 16; j ++)
digest[j] = (uint8_t)(pdf->encryption_key[j] ^ i);
_pdfioCryptoRC4Init(&rc4, digest, 16);
_pdfioCryptoRC4Crypt(&rc4, pdf->user_key, sizeof(pdf->user_key));
}
// Save everything in the dictionary...
pdfioDictSetNumber(dict, "Length", 128);
pdfioDictSetBinary(dict, "O", pdf->owner_key, sizeof(pdf->owner_key));
pdfioDictSetNumber(dict, "P", (int)permissions);
pdfioDictSetNumber(dict, "R", encryption == PDFIO_ENCRYPTION_RC4_128 ? 3 : 4);
pdfioDictSetNumber(dict, "V", encryption == PDFIO_ENCRYPTION_RC4_128 ? 3 : 4);
pdfioDictSetBinary(dict, "U", pdf->user_key, sizeof(pdf->user_key));
break;
case PDFIO_ENCRYPTION_AES_256 :
// TODO: Implement AES-256 (/V 6 /R 6)
default :
_pdfioFileError(pdf, "Encryption mode %d not supported for writing.", (int)encryption);
return (false);
}
if ((pdf->encrypt_obj = pdfioFileCreateObj(pdf, dict)) == NULL)
{
_pdfioFileError(pdf, "Unable to create encryption object.");
return (false);
}
pdfioObjClose(pdf->encrypt_obj);
pdf->encryption = encryption;
pdf->permissions = permissions;
return (true);
}
//
// 'pdfioFileSetSubject()' - Set the subject for a PDF file.
//
void
pdfioFileSetSubject(
pdfio_file_t *pdf, // I - PDF file
const char *value) // I - Value
{
if (pdf && pdf->info)
pdfioDictSetString(pdf->info->value.value.dict, "Subject", pdfioStringCreate(pdf, value));
}
//
// 'pdfioFileSetTitle()' - Set the title for a PDF file.
//
void
pdfioFileSetTitle(pdfio_file_t *pdf, // I - PDF file
const char *value) // I - Value
{
if (pdf && pdf->info)
pdfioDictSetString(pdf->info->value.value.dict, "Title", pdfioStringCreate(pdf, value));
}
//
// '_pdfioObjAdd()' - Add an object to a file.
//
static pdfio_obj_t * // O - Object
add_obj(pdfio_file_t *pdf, // I - PDF file
size_t number, // I - Object number
unsigned short generation, // I - Object generation
off_t offset) // I - Offset in file
{
pdfio_obj_t *obj; // Object
// Allocate memory for the object...
if ((obj = (pdfio_obj_t *)calloc(1, sizeof(pdfio_obj_t))) == NULL)
{
_pdfioFileError(pdf, "Unable to allocate memory for object - %s", strerror(errno));
return (NULL);
}
// Expand the objects array as needed
if (pdf->num_objs >= pdf->alloc_objs)
{
pdfio_obj_t **temp = (pdfio_obj_t **)realloc(pdf->objs, (pdf->alloc_objs + 32) * sizeof(pdfio_obj_t *));
if (!temp)
{
_pdfioFileError(pdf, "Unable to allocate memory for object - %s", strerror(errno));
free(obj);
return (NULL);
}
pdf->objs = temp;
pdf->alloc_objs += 32;
}
pdf->objs[pdf->num_objs ++] = obj;
obj->pdf = pdf;
obj->number = number;
obj->generation = generation;
obj->offset = offset;
PDFIO_DEBUG("add_obj: obj=%p, ->pdf=%p, ->number=%lu\n", obj, pdf, (unsigned long)obj->number);
// Re-sort object array as needed...
if (pdf->num_objs > 1 && pdf->objs[pdf->num_objs - 2]->number > number)
qsort(pdf->objs, pdf->num_objs, sizeof(pdfio_obj_t *), (int (*)(const void *, const void *))compare_objs);
return (obj);
}
//
// 'compare_objmaps()' - Compare two object maps...
//
static int // O - Result of comparison
compare_objmaps(_pdfio_objmap_t *a, // I - First object map
_pdfio_objmap_t *b) // I - Second object map
{
if (a->src_pdf < b->src_pdf)
return (-1);
else if (a->src_pdf > b->src_pdf)
return (1);
else if (a->src_number < b->src_number)
return (-1);
else if (a->src_number > b->src_number)
return (1);
else
return (0);
}
//
// 'compare_objs()' - Compare the object numbers of two objects.
//
static int // O - Result of comparison
compare_objs(pdfio_obj_t **a, // I - First object
pdfio_obj_t **b) // I - Second object
{
if ((*a)->number < (*b)->number)
return (-1);
else if ((*a)->number == (*b)->number)
return (0);
else
return (1);
}
//
// 'load_obj_stream()' - Load an object stream.
//
// Object streams are Adobe's complicated solution for saving a few
// kilobytes in an average PDF file at the expense of massively more
// complicated reader applications.
//
// Each object stream starts with pairs of object numbers and offsets,
// followed by the object values (typically dictionaries). For
// simplicity pdfio loads all of these values into memory so that we
// don't later have to randomly access compressed stream data to get
// a dictionary.
//
static bool // O - `true` on success, `false` on error
load_obj_stream(pdfio_obj_t *obj) // I - Object to load
{
pdfio_stream_t *st; // Stream
_pdfio_token_t tb; // Token buffer/stack
char buffer[32]; // Token
size_t number, // Object number
cur_obj, // Current object
num_objs = 0; // Number of objects
pdfio_obj_t *objs[16384]; // Objects
PDFIO_DEBUG("load_obj_stream(obj=%p(%d))\n", obj, (int)obj->number);
// Open the object stream...
if ((st = pdfioObjOpenStream(obj, true)) == NULL)
{
_pdfioFileError(obj->pdf, "Unable to open compressed object stream %lu.", (unsigned long)obj->number);
return (false);
}
_pdfioTokenInit(&tb, obj->pdf, (_pdfio_tconsume_cb_t)pdfioStreamConsume, (_pdfio_tpeek_cb_t)pdfioStreamPeek, st);
// Read the object numbers from the beginning of the stream...
while (_pdfioTokenGet(&tb, buffer, sizeof(buffer)))
{
// Stop if this isn't an object number...
if (!isdigit(buffer[0] & 255))
break;
// Stop if we have too many objects...
if (num_objs >= (sizeof(objs) / sizeof(objs[0])))
{
_pdfioFileError(obj->pdf, "Too many compressed objects in one stream.");
pdfioStreamClose(st);
return (false);
}
// Add the object in memory...
number = (size_t)strtoimax(buffer, NULL, 10);
if ((objs[num_objs] = pdfioFileFindObj(obj->pdf, number)) == NULL)
objs[num_objs] = add_obj(obj->pdf, number, 0, 0);
num_objs ++;
// Skip offset
_pdfioTokenGet(&tb, buffer, sizeof(buffer));
}
if (!buffer[0])
{
pdfioStreamClose(st);
return (false);
}
_pdfioTokenPush(&tb, buffer);
// Read the objects themselves...
for (cur_obj = 0; cur_obj < num_objs; cur_obj ++)
{
if (!_pdfioValueRead(obj->pdf, &tb, &(objs[cur_obj]->value)))
{
pdfioStreamClose(st);
return (false);
}
}
// Close the stream and return
pdfioStreamClose(st);
return (true);
}
//
// 'load_pages()' - Load pages in the document.
//
static bool // O - `true` on success, `false` on error
load_pages(pdfio_file_t *pdf, // I - PDF file
pdfio_obj_t *obj) // I - Page object
{
pdfio_dict_t *dict; // Page object dictionary
const char *type; // Node type
pdfio_array_t *kids; // Kids array
// Range check input...
if (!obj)
{
_pdfioFileError(pdf, "Unable to find pages object.");
return (false);
}
// Get the object dictionary and make sure this is a Pages or Page object...
if ((dict = pdfioObjGetDict(obj)) == NULL)
{
_pdfioFileError(pdf, "No dictionary for pages object.");
return (false);
}
if ((type = pdfioDictGetName(dict, "Type")) == NULL || (strcmp(type, "Pages") && strcmp(type, "Page")))
return (false);
// If there is a Kids array, then this is a parent node and we have to look
// at the child objects...
if ((kids = pdfioDictGetArray(dict, "Kids")) != NULL)
{
// Load the child objects...
size_t i, // Looping var
num_kids; // Number of elements in array
for (i = 0, num_kids = pdfioArrayGetSize(kids); i < num_kids; i ++)
{
if (!load_pages(pdf, pdfioArrayGetObj(kids, i)))
return (false);
}
}
else
{
// Add this page...
if (pdf->num_pages >= pdf->alloc_pages)
{
pdfio_obj_t **temp = (pdfio_obj_t **)realloc(pdf->pages, (pdf->alloc_pages + 32) * sizeof(pdfio_obj_t *));
if (!temp)
{
_pdfioFileError(pdf, "Unable to allocate memory for pages.");
return (false);
}
pdf->alloc_pages += 32;
pdf->pages = temp;
}
pdf->pages[pdf->num_pages ++] = obj;
}
return (true);
}
//
// 'load_xref()' - Load an XREF table...
//
static bool // O - `true` on success, `false` on failure
load_xref(pdfio_file_t *pdf, // I - PDF file
off_t xref_offset) // I - Offset to xref
{
bool done = false; // Are we done?
char line[1024], // Line from file
*ptr; // Pointer into line
_pdfio_value_t trailer; // Trailer dictionary
intmax_t number, // Object number
num_objects, // Number of objects
offset; // Offset in file
int generation; // Generation number
_pdfio_token_t tb; // Token buffer/stack
while (!done)
{
if (_pdfioFileSeek(pdf, xref_offset, SEEK_SET) != xref_offset)
{
_pdfioFileError(pdf, "Unable to seek to start of xref table.");
return (false);
}
do
{
if (!_pdfioFileGets(pdf, line, sizeof(line)))
{
_pdfioFileError(pdf, "Unable to read start of xref table.");
return (false);
}
}
while (!line[0]);
PDFIO_DEBUG("load_xref: xref_offset=%lu, line='%s'\n", (unsigned long)xref_offset, line);
if (isdigit(line[0] & 255) && strlen(line) > 4 && (!strcmp(line + strlen(line) - 4, " obj") || ((ptr = strstr(line, " obj")) != NULL && ptr[4] == '<')))
{
// Cross-reference stream
pdfio_obj_t *obj; // Object
size_t i; // Looping var
pdfio_array_t *index_array; // Index array
size_t index_n, // Current element in array
index_count, // Number of values in index array
count; // Number of objects in current pairing
pdfio_array_t *w_array; // W array
size_t w[3]; // Size of each cross-reference field
size_t w_2, // Offset to second field
w_3; // Offset to third field
size_t w_total; // Total length
pdfio_stream_t *st; // Stream
unsigned char buffer[32]; // Read buffer
size_t num_sobjs = 0, // Number of object streams
sobjs[4096]; // Object streams to load
pdfio_obj_t *current; // Current object
if ((number = strtoimax(line, &ptr, 10)) < 1)
{
_pdfioFileError(pdf, "Bad xref table header '%s'.", line);
return (false);
}
if ((generation = (int)strtol(ptr, &ptr, 10)) < 0 || generation > 65535)
{
_pdfioFileError(pdf, "Bad xref table header '%s'.", line);
return (false);
}
while (isspace(*ptr & 255))
ptr ++;
if (strncmp(ptr, "obj", 3))
{
_pdfioFileError(pdf, "Bad xref table header '%s'.", line);
return (false);
}
if (_pdfioFileSeek(pdf, xref_offset + ptr + 3 - line, SEEK_SET) < 0)
{
_pdfioFileError(pdf, "Unable to seek to xref object %lu %u.", (unsigned long)number, (unsigned)generation);
return (false);
}
PDFIO_DEBUG("load_xref: Loading object %lu %u.\n", (unsigned long)number, (unsigned)generation);
if ((obj = add_obj(pdf, (size_t)number, (unsigned short)generation, xref_offset)) == NULL)
{
_pdfioFileError(pdf, "Unable to allocate memory for object.");
return (false);
}
_pdfioTokenInit(&tb, pdf, (_pdfio_tconsume_cb_t)_pdfioFileConsume, (_pdfio_tpeek_cb_t)_pdfioFilePeek, pdf);
if (!_pdfioValueRead(pdf, &tb, &trailer))
{
_pdfioFileError(pdf, "Unable to read cross-reference stream dictionary.");
return (false);
}
else if (trailer.type != PDFIO_VALTYPE_DICT)
{
_pdfioFileError(pdf, "Cross-reference stream does not have a dictionary.");
return (false);
}
else if (_pdfioDictGetValue(pdf->trailer, "Encrypt"))
{
// Encryption not yet supported...
_pdfioFileError(pdf, "Sorry, PDFio currently does not support encrypted PDF files.");
return (false);
}
obj->value = trailer;
if (!_pdfioTokenGet(&tb, line, sizeof(line)) || strcmp(line, "stream"))
{
_pdfioFileError(pdf, "Unable to get stream after xref dictionary.");
return (false);
}
_pdfioTokenFlush(&tb);
obj->stream_offset = _pdfioFileTell(pdf);
if ((index_array = pdfioDictGetArray(trailer.value.dict, "Index")) != NULL)
index_count = index_array->num_values;
else
index_count = 1;
if ((w_array = pdfioDictGetArray(trailer.value.dict, "W")) == NULL)
{
_pdfioFileError(pdf, "Cross-reference stream does not have required W key.");
return (false);
}
w[0] = (size_t)pdfioArrayGetNumber(w_array, 0);
w[1] = (size_t)pdfioArrayGetNumber(w_array, 1);
w[2] = (size_t)pdfioArrayGetNumber(w_array, 2);
w_total = w[0] + w[1] + w[2];
w_2 = w[0];
w_3 = w[0] + w[1];
if (w[1] == 0 || w[2] > 2 || w_total > sizeof(buffer))
{
_pdfioFileError(pdf, "Cross-reference stream has invalid W key.");
return (false);
}
if ((st = pdfioObjOpenStream(obj, true)) == NULL)
{
_pdfioFileError(pdf, "Unable to open cross-reference stream.");
return (false);
}
for (index_n = 0; index_n < index_count; index_n += 2)
{
if (index_count == 1)
{
number = 0;
count = 999999999;
}
else
{
number = (intmax_t)pdfioArrayGetNumber(index_array, index_n);
count = (size_t)pdfioArrayGetNumber(index_array, index_n + 1);
}
while (count > 0 && pdfioStreamRead(st, buffer, w_total) > 0)
{
count --;
PDFIO_DEBUG("load_xref: number=%u %02X%02X%02X%02X%02X\n", (unsigned)number, buffer[0], buffer[1], buffer[2], buffer[3], buffer[4]);
// Check whether this is an object definition...
if (w[0] > 0)
{
if (buffer[0] == 0)
{
// Ignore free objects...
number ++;
continue;
}
}
for (i = 1, offset = buffer[w_2]; i < w[1]; i ++)
offset = (offset << 8) | buffer[w_2 + i];
switch (w[2])
{
default :
generation = 0;
break;
case 1 :
generation = buffer[w_3];
break;
case 2 :
generation = (buffer[w_3] << 8) | buffer[w_3 + 1];
break;
}
// Create a placeholder for the object in memory...
if ((current = pdfioFileFindObj(pdf, (size_t)number)) != NULL)
{
PDFIO_DEBUG("load_xref: existing object, prev offset=%u\n", (unsigned)current->offset);
if (w[0] == 0 || buffer[0] == 1)
{
// Location of object...
current->offset = offset;
}
else if (number != offset)
{
// Object is part of a stream, offset is the object number...
current->offset = 0;
}
PDFIO_DEBUG("load_xref: new offset=%u\n", (unsigned)current->offset);
}
if (w[0] > 0 && buffer[0] == 2)
{
// Object streams need to be loaded into memory, so add them
// to the list of objects to load later as needed...
for (i = 0; i < num_sobjs; i ++)
{
if (sobjs[i] == (size_t)offset)
break;
}
if (i >= num_sobjs && num_sobjs < (sizeof(sobjs) / sizeof(sobjs[0])))
sobjs[num_sobjs ++] = (size_t)offset;
}
else if (!current)
{
// Add this object...
if (!add_obj(pdf, (size_t)number, (unsigned short)generation, offset))
return (false);
}
number ++;
}
}
pdfioStreamClose(st);
// Load any object streams that are left...
PDFIO_DEBUG("load_xref: %lu compressed object streams to load.\n", (unsigned long)num_sobjs);
for (i = 0; i < num_sobjs; i ++)
{
if ((obj = pdfioFileFindObj(pdf, sobjs[i])) != NULL)
{
PDFIO_DEBUG("load_xref: Loading compressed object stream %lu (pdf=%p, obj->pdf=%p).\n", (unsigned long)sobjs[i], pdf, obj->pdf);
if (!load_obj_stream(obj))
return (false);
}
else
{
_pdfioFileError(pdf, "Unable to find compressed object stream %lu.", (unsigned long)sobjs[i]);
return (false);
}
}
}
else if (!strcmp(line, "xref"))
{
// Read the xref tables
while (_pdfioFileGets(pdf, line, sizeof(line)))
{
if (!strcmp(line, "trailer"))
break;
else if (!line[0])
continue;
if (sscanf(line, "%jd%jd", &number, &num_objects) != 2)
{
_pdfioFileError(pdf, "Malformed xref table section '%s'.", line);
return (false);
}
// Read this group of objects...
for (; num_objects > 0; num_objects --, number ++)
{
// Read a line from the file and validate it...
if (_pdfioFileRead(pdf, line, 20) != 20)
return (false);
line[20] = '\0';
if (strcmp(line + 18, "\r\n") && strcmp(line + 18, " \n") && strcmp(line + 18, " \r"))
{
_pdfioFileError(pdf, "Malformed xref table entry '%s'.", line);
return (false);
}
line[18] = '\0';
// Parse the line
if ((offset = strtoimax(line, &ptr, 10)) < 0)
{
_pdfioFileError(pdf, "Malformed xref table entry '%s'.", line);
return (false);
}
if ((generation = (int)strtol(ptr, &ptr, 10)) < 0 || generation > 65535)
{
_pdfioFileError(pdf, "Malformed xref table entry '%s'.", line);
return (false);
}
if (*ptr != ' ')
{
_pdfioFileError(pdf, "Malformed xref table entry '%s'.", line);
return (false);
}
ptr ++;
if (*ptr != 'f' && *ptr != 'n')
{
_pdfioFileError(pdf, "Malformed xref table entry '%s'.", line);
return (false);
}
if (*ptr == 'f')
continue; // Don't care about free objects...
// Create a placeholder for the object in memory...
if (pdfioFileFindObj(pdf, (size_t)number))
continue; // Don't replace newer object...
if (!add_obj(pdf, (size_t)number, (unsigned short)generation, offset))
return (false);
}
}
if (strcmp(line, "trailer"))
{
_pdfioFileError(pdf, "Missing trailer.");
return (false);
}
_pdfioTokenInit(&tb, pdf, (_pdfio_tconsume_cb_t)_pdfioFileConsume, (_pdfio_tpeek_cb_t)_pdfioFilePeek, pdf);
if (!_pdfioValueRead(pdf, &tb, &trailer))
{
_pdfioFileError(pdf, "Unable to read trailer dictionary.");
return (false);
}
else if (trailer.type != PDFIO_VALTYPE_DICT)
{
_pdfioFileError(pdf, "Trailer is not a dictionary.");
return (false);
}
else if (_pdfioDictGetValue(pdf->trailer, "Encrypt"))
{
// Encryption not yet supported...
_pdfioFileError(pdf, "Sorry, PDFio currently does not support encrypted PDF files.");
return (false);
}
_pdfioTokenFlush(&tb);
}
else
{
_pdfioFileError(pdf, "Bad xref table header '%s'.", line);
return (false);
}
PDFIO_DEBUG("load_xref: Contents of trailer dictionary:\n");
PDFIO_DEBUG("load_xref: ");
PDFIO_DEBUG_VALUE(&trailer);
PDFIO_DEBUG("\n");
if (!pdf->trailer)
{
// Save the trailer dictionary and grab the root (catalog) and info
// objects...
pdf->trailer = trailer.value.dict;
}
if ((xref_offset = (off_t)pdfioDictGetNumber(trailer.value.dict, "Prev")) <= 0)
done = true;
}
// Once we have all of the xref tables loaded, get the important objects and
// build the pages array...
if ((pdf->root = pdfioDictGetObj(pdf->trailer, "Root")) == NULL)
{
_pdfioFileError(pdf, "Missing Root object.");
return (false);
}
PDFIO_DEBUG("load_xref: Root=%p(%lu)\n", pdf->root, (unsigned long)pdf->root->number);
pdf->info = pdfioDictGetObj(pdf->trailer, "Info");
pdf->encrypt_obj = pdfioDictGetObj(pdf->trailer, "Encrypt");
pdf->id_array = pdfioDictGetArray(pdf->trailer, "ID");
return (load_pages(pdf, pdfioDictGetObj(pdfioObjGetDict(pdf->root), "Pages")));
}
//
// 'write_catalog()' - Write the PDF root object/catalog.
//
static bool // O - `true` on success, `false` on failure
write_catalog(pdfio_file_t *pdf) // I - PDF file
{
pdfio_dict_t *dict; // Dictionary for catalog...
if ((dict = pdfioDictCreate(pdf)) == NULL)
return (false);
pdfioDictSetName(dict, "Type", "Catalog");
pdfioDictSetObj(dict, "Pages", pdf->pages_root);
// TODO: Add support for all of the root object dictionary keys
if ((pdf->root = pdfioFileCreateObj(pdf, dict)) == NULL)
return (false);
else
return (pdfioObjClose(pdf->root));
}
//
// 'write_pages()' - Write the PDF pages objects.
//
static bool // O - `true` on success, `false` on failure
write_pages(pdfio_file_t *pdf) // I - PDF file
{
pdfio_array_t *kids; // Pages array
size_t i; // Looping var
// Build the "Kids" array pointing to each page...
if ((kids = pdfioArrayCreate(pdf)) == NULL)
return (false);
for (i = 0; i < pdf->num_pages; i ++)
pdfioArrayAppendObj(kids, pdf->pages[i]);
pdfioDictSetNumber(pdf->pages_root->value.value.dict, "Count", pdf->num_pages);
pdfioDictSetArray(pdf->pages_root->value.value.dict, "Kids", kids);
// Write the Pages object...
return (pdfioObjClose(pdf->pages_root));
}
//
// 'write_trailer()' - Write the PDF catalog object, xref table, and trailer.
//
static bool // O - `true` on success, `false` on failure
write_trailer(pdfio_file_t *pdf) // I - PDF file
{
bool ret = true; // Return value
off_t xref_offset; // Offset to xref table
size_t i; // Looping var
unsigned char id_values[2][16]; // ID array values
// Write the xref table...
// TODO: Look at adding support for xref streams...
xref_offset = _pdfioFileTell(pdf);
if (!_pdfioFilePrintf(pdf, "xref\n0 %lu \n0000000000 65535 f \n", (unsigned long)pdf->num_objs + 1))
{
_pdfioFileError(pdf, "Unable to write cross-reference table.");
ret = false;
goto done;
}
for (i = 0; i < pdf->num_objs; i ++)
{
pdfio_obj_t *obj = pdf->objs[i]; // Current object
if (!_pdfioFilePrintf(pdf, "%010lu %05u n \n", (unsigned long)obj->offset, obj->generation))
{
_pdfioFileError(pdf, "Unable to write cross-reference table.");
ret = false;
goto done;
}
}
// Write the trailer...
if (!_pdfioFilePuts(pdf, "trailer\n"))
{
_pdfioFileError(pdf, "Unable to write trailer.");
ret = false;
goto done;
}
_pdfioCryptoMakeRandom(id_values[0], sizeof(id_values[0]));
_pdfioCryptoMakeRandom(id_values[1], sizeof(id_values[1]));
if ((pdf->id_array = pdfioArrayCreate(pdf)) != NULL)
{
pdfioArrayAppendBinary(pdf->id_array, id_values[0], sizeof(id_values[0]));
pdfioArrayAppendBinary(pdf->id_array, id_values[1], sizeof(id_values[1]));
}
if ((pdf->trailer = pdfioDictCreate(pdf)) == NULL)
{
ret = false;
goto done;
}
if (pdf->encrypt_obj)
pdfioDictSetObj(pdf->trailer, "Encrypt", pdf->encrypt_obj);
if (pdf->id_array)
pdfioDictSetArray(pdf->trailer, "ID", pdf->id_array);
pdfioDictSetObj(pdf->trailer, "Info", pdf->info);
pdfioDictSetObj(pdf->trailer, "Root", pdf->root);
pdfioDictSetNumber(pdf->trailer, "Size", pdf->num_objs + 1);
if (!_pdfioDictWrite(pdf->trailer, NULL))
{
_pdfioFileError(pdf, "Unable to write trailer.");
ret = false;
goto done;
}
if (!_pdfioFilePrintf(pdf, "\nstartxref\n%lu\n%%EOF\n", (unsigned long)xref_offset))
{
_pdfioFileError(pdf, "Unable to write xref offset.");
ret = false;
}
done:
return (ret);
}
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