Fix pdfioFileGetAuthor, etc. APIs (Issue #33)

CHANGES.md

@@ -11,6 +11,7 @@ v1.1.0 (Month DD, YYYY)
 - Added protection against opening multiple streams in the same file at the
   same time.
 - Fixed "install-shared" target (Issue #32)
+- Fixed `pdfioFileGet...` metadata APIs (Issue #33)
 - Fixed `pdfioContentMatrixRotate` function.
 
 

pdfio-file.c

@@ -24,6 +24,7 @@
 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 const char	*get_info_string(pdfio_file_t *pdf, const char *key);
 static bool		load_obj_stream(pdfio_obj_t *obj);
 static bool		load_pages(pdfio_file_t *pdf, pdfio_obj_t *obj, size_t depth);
 static bool		load_xref(pdfio_file_t *pdf, off_t xref_offset, pdfio_password_cb_t password_cb, void *password_data);
@@ -892,7 +893,7 @@ pdfioFileFindObj(
 const char *				// O - Author or `NULL` for none
 pdfioFileGetAuthor(pdfio_file_t *pdf)	// I - PDF file
 {
-  return (pdf && pdf->info_obj ? pdfioDictGetString(pdf->info_obj->value.value.dict, "Author") : NULL);
+  return (get_info_string(pdf, "Author"));
 }
 
 
@@ -904,7 +905,7 @@ time_t					// O - Creation date or `0` for none
 pdfioFileGetCreationDate(
     pdfio_file_t *pdf)			// I - PDF file
 {
-  return (pdf && pdf->info_obj ? pdfioDictGetDate(pdf->info_obj->value.value.dict, "CreationDate") : 0);
+  return (pdf && pdf->info_obj ? pdfioDictGetDate(pdfioObjGetDict(pdf->info_obj), "CreationDate") : 0);
 }
 
 
@@ -915,7 +916,7 @@ pdfioFileGetCreationDate(
 const char *				// O - Creator string or `NULL` for none
 pdfioFileGetCreator(pdfio_file_t *pdf)	// I - PDF file
 {
-  return (pdf && pdf->info_obj ? pdfioDictGetString(pdf->info_obj->value.value.dict, "Creator") : NULL);
+  return (get_info_string(pdf, "Creator"));
 }
 
 
@@ -937,7 +938,7 @@ pdfioFileGetID(pdfio_file_t *pdf)	// I - PDF file
 const char *				// O - Keywords string or `NULL` for none
 pdfioFileGetKeywords(pdfio_file_t *pdf)	// I - PDF file
 {
-  return (pdf && pdf->info_obj ? pdfioDictGetString(pdf->info_obj->value.value.dict, "Keywords") : NULL);
+  return (get_info_string(pdf, "Keywords"));
 }
 
 
@@ -1041,7 +1042,7 @@ pdfioFileGetPermissions(
 const char *				// O - Producer string or `NULL` for none
 pdfioFileGetProducer(pdfio_file_t *pdf)	// I - PDF file
 {
-  return (pdf && pdf->info_obj ? pdfioDictGetString(pdf->info_obj->value.value.dict, "Producer") : NULL);
+  return (get_info_string(pdf, "Producer"));
 }
 
 
@@ -1052,7 +1053,7 @@ pdfioFileGetProducer(pdfio_file_t *pdf)	// I - PDF file
 const char *				// O - Subject or `NULL` for none
 pdfioFileGetSubject(pdfio_file_t *pdf)	// I - PDF file
 {
-  return (pdf && pdf->info_obj ? pdfioDictGetString(pdf->info_obj->value.value.dict, "Subject") : NULL);
+  return (get_info_string(pdf, "Subject"));
 }
 
 
@@ -1063,7 +1064,7 @@ pdfioFileGetSubject(pdfio_file_t *pdf)	// I - PDF file
 const char *				// O - Title or `NULL` for none
 pdfioFileGetTitle(pdfio_file_t *pdf)	// I - PDF file
 {
-  return (pdf && pdf->info_obj ? pdfioDictGetString(pdf->info_obj->value.value.dict, "Title") : NULL);
+  return (get_info_string(pdf, "Title"));
 }
 
 
@@ -1406,6 +1407,51 @@ compare_objs(pdfio_obj_t **a,		// I - First object
 }
 
 
+//
+// 'get_info_string()' - Get a string value from the Info dictionary.
+//
+// This function also handles converting binary strings to C strings, which
+// occur in encrypted PDF files.
+//
+
+static const char *			// O - String or `NULL` if not found
+get_info_string(pdfio_file_t *pdf,	// I - PDF file
+                const char   *key)	// I - Dictionary key
+{
+  pdfio_dict_t	*dict;			// Info dictionary
+  _pdfio_value_t *value;		// Value
+
+  // Range check input...
+  if (!pdf || !pdf->info_obj || (dict = pdfioObjGetDict(pdf->info_obj)) == NULL || (value = _pdfioDictGetValue(dict, key)) == NULL)
+    return (NULL);
+
+  // If we already have a value, return it...
+  if (value->type == PDFIO_VALTYPE_NAME || value->type == PDFIO_VALTYPE_STRING)
+  {
+    return (value->value.string);
+  }
+  else if (value->type == PDFIO_VALTYPE_BINARY && value->value.binary.datalen < 4096)
+  {
+    // Convert binary string to regular string...
+    char	temp[4096];		// Temporary string
+
+    memcpy(temp, value->value.binary.data, value->value.binary.datalen);
+    temp[value->value.binary.datalen] = '\0';
+
+    free(value->value.binary.data);
+    value->type         = PDFIO_VALTYPE_STRING;
+    value->value.string = pdfioStringCreate(pdf, temp);
+
+    return (value->value.string);
+  }
+  else
+  {
+    // Something else that is not a string...
+    return (NULL);
+  }
+}
+
+
 //
 // 'load_obj_stream()' - Load an object stream.
 //

pdfio-value.c

@@ -219,7 +219,6 @@ _pdfioValueRead(pdfio_file_t   *pdf,	// I - PDF file
 
 
   PDFIO_DEBUG("_pdfioValueRead(pdf=%p, obj=%p, v=%p)\n", pdf, obj, v);
-  (void)obj; // TODO: Implement decryption
 
   if (!_pdfioTokenGet(tb, token, sizeof(token)))
     return (NULL);
@@ -284,6 +283,7 @@ _pdfioValueRead(pdfio_file_t   *pdf,	// I - PDF file
 	}
       }
     }
+
     if (token[i])
     {
       // Just a string...
@@ -367,6 +367,33 @@ _pdfioValueRead(pdfio_file_t   *pdf,	// I - PDF file
 
       *dataptr++ = (unsigned char)d;
     }
+
+    if (obj && pdf->encryption)
+    {
+      // Decrypt the string...
+      _pdfio_crypto_ctx_t ctx;		// Decryption context
+      _pdfio_crypto_cb_t cb;		// Decryption callback
+      size_t	ivlen;			// Number of initialization vector bytes
+      uint8_t	temp[32768];		// Temporary buffer for decryption
+      size_t	templen;		// Number of actual data bytes
+
+      if (v->value.binary.datalen > (sizeof(temp) - 32))
+      {
+	_pdfioFileError(pdf, "Unable to read encrypted binary string - too long.");
+	return (false);
+      }
+
+      cb      = _pdfioCryptoMakeReader(pdf, obj, &ctx, v->value.binary.data, &ivlen);
+      templen = (cb)(&ctx, temp, v->value.binary.data + ivlen, v->value.binary.datalen - ivlen);
+
+      // Copy the decrypted string back to the value and adjust the length...
+      memcpy(v->value.binary.data, temp, templen);
+
+      if (pdf->encryption >= PDFIO_ENCRYPTION_AES_128)
+        v->value.binary.datalen = templen - temp[templen - 1];
+      else
+	v->value.binary.datalen = templen;
+    }
   }
   else if (strchr("0123456789-+.", token[0]) != NULL)
   {

testpdfio.c

@@ -1310,6 +1310,7 @@ read_unit_file(const char *filename,	// I - File to read
 {
   pdfio_file_t	*pdf;			// PDF file
   size_t	i;			// Looping var
+  const char	*s;			// String
   bool		error = false;		// Error callback data
 
 
@@ -1320,6 +1321,87 @@ read_unit_file(const char *filename,	// I - File to read
   else
     return (1);
 
+  // Verify metadata...
+  fputs("pdfioFileGetAuthor: ", stdout);
+  if ((s = pdfioFileGetAuthor(pdf)) != NULL && !strcmp(s, "Michael R Sweet"))
+  {
+    puts("PASS");
+  }
+  else if (s)
+  {
+    printf("FAIL (got '%s', expected 'Michael R Sweet')\n", s);
+    return (1);
+  }
+  else
+  {
+    puts("FAIL (got NULL, expected 'Michael R Sweet')");
+    return (1);
+  }
+
+  fputs("pdfioFileGetCreator: ", stdout);
+  if ((s = pdfioFileGetCreator(pdf)) != NULL && !strcmp(s, "testpdfio"))
+  {
+    puts("PASS");
+  }
+  else if (s)
+  {
+    printf("FAIL (got '%s', expected 'testpdfio')\n", s);
+    return (1);
+  }
+  else
+  {
+    puts("FAIL (got NULL, expected 'testpdfio')");
+    return (1);
+  }
+
+  fputs("pdfioFileGetKeywords: ", stdout);
+  if ((s = pdfioFileGetKeywords(pdf)) != NULL && !strcmp(s, "one fish,two fish,red fish,blue fish"))
+  {
+    puts("PASS");
+  }
+  else if (s)
+  {
+    printf("FAIL (got '%s', expected 'one fish,two fish,red fish,blue fish')\n", s);
+    return (1);
+  }
+  else
+  {
+    puts("FAIL (got NULL, expected 'one fish,two fish,red fish,blue fish')");
+    return (1);
+  }
+
+  fputs("pdfioFileGetSubject: ", stdout);
+  if ((s = pdfioFileGetSubject(pdf)) != NULL && !strcmp(s, "Unit test document"))
+  {
+    puts("PASS");
+  }
+  else if (s)
+  {
+    printf("FAIL (got '%s', expected 'Unit test document')\n", s);
+    return (1);
+  }
+  else
+  {
+    puts("FAIL (got NULL, expected 'Unit test document')");
+    return (1);
+  }
+
+  fputs("pdfioFileGetTitle: ", stdout);
+  if ((s = pdfioFileGetTitle(pdf)) != NULL && !strcmp(s, "Test Document"))
+  {
+    puts("PASS");
+  }
+  else if (s)
+  {
+    printf("FAIL (got '%s', expected 'Test Document')\n", s);
+    return (1);
+  }
+  else
+  {
+    puts("FAIL (got NULL, expected 'Test Document')");
+    return (1);
+  }
+
   // Verify the number of pages is the same...
   fputs("pdfioFileGetNumPages: ", stdout);
   if (num_pages == pdfioFileGetNumPages(pdf))