C
C
PDF Get Encryption and Permissions Information
See more PDF Signatures Examples
Determine if a PDF is encrypted, and the associated user permissions.Note: Some PDFs are encrypted but not password-protected. In such cases, encryption is used primarily for preventing unauthorized modifications to the document, but it doesn't restrict access. Therefore, you can open and read the document without a password.
Chilkat C Downloads
#include <C_CkPdf.h>
#include <C_CkJsonObject.h>
void ChilkatSample(void)
{
BOOL success;
HCkPdf pdf;
HCkJsonObject ljd;
const char *pdfVersion;
const char *Filter;
int KeyLength;
int V;
int R;
int P;
const char *PrintLowResolution;
const char *PrintHighResolution;
const char *ModifyOther;
const char *ModifyAnnotations;
const char *ModifyForms;
const char *FillInForms;
const char *AssembleDoc;
const char *ExtractAnyPurpose;
const char *ExtractAccessibility;
const char *Method;
success = FALSE;
// This example requires the Chilkat API to have been previously unlocked.
// See Global Unlock Sample for sample code.
pdf = CkPdf_Create();
// Load a PDF.
success = CkPdf_LoadFile(pdf,"c:/someDir/sample.pdf");
if (success == FALSE) {
printf("%s\n",CkPdf_lastErrorText(pdf));
CkPdf_Dispose(pdf);
return;
}
// Get information about the PDF that was collected in the call to LoadFile.
ljd = CkJsonObject_Create();
CkPdf_GetLastJsonData(pdf,ljd);
CkJsonObject_putEmitCompact(ljd,FALSE);
printf("%s\n",CkJsonObject_emit(ljd));
// Sample output:
// {
// "pdfVersion": "1.6",
// "encrypt": {
// "filter": "/Standard",
// "keyLength": 128,
// "V": 4,
// "R": 4,
// "P": -1340,
// "perm": {
// "printLowResolution": "allowed",
// "printHighResolution": "allowed",
// "modifyOther": "not allowed",
// "modifyAnnotations": "allowed",
// "modifyForms": "not allowed",
// "fillInForms": "allowed",
// "assembleDoc": "allowed",
// "extractAnyPurpose": "not allowed",
// "extractAccessibility": "not allowed"
// },
// "method": "AESV2"
// }
// }
// Use this online tool to generate parsing code from sample JSON:
// Generate Parsing Code from JSON
// Chilkat functions returning "const char *" return a pointer to temporary internal memory owned and managed by Chilkat.
// See this example explaining how this memory should be used: const char * functions.
pdfVersion = CkJsonObject_stringOf(ljd,"pdfVersion");
Filter = CkJsonObject_stringOf(ljd,"encrypt.filter");
KeyLength = CkJsonObject_IntOf(ljd,"encrypt.keyLength");
V = CkJsonObject_IntOf(ljd,"encrypt.V");
R = CkJsonObject_IntOf(ljd,"encrypt.R");
P = CkJsonObject_IntOf(ljd,"encrypt.P");
PrintLowResolution = CkJsonObject_stringOf(ljd,"encrypt.perm.printLowResolution");
PrintHighResolution = CkJsonObject_stringOf(ljd,"encrypt.perm.printHighResolution");
ModifyOther = CkJsonObject_stringOf(ljd,"encrypt.perm.modifyOther");
ModifyAnnotations = CkJsonObject_stringOf(ljd,"encrypt.perm.modifyAnnotations");
ModifyForms = CkJsonObject_stringOf(ljd,"encrypt.perm.modifyForms");
FillInForms = CkJsonObject_stringOf(ljd,"encrypt.perm.fillInForms");
AssembleDoc = CkJsonObject_stringOf(ljd,"encrypt.perm.assembleDoc");
ExtractAnyPurpose = CkJsonObject_stringOf(ljd,"encrypt.perm.extractAnyPurpose");
ExtractAccessibility = CkJsonObject_stringOf(ljd,"encrypt.perm.extractAccessibility");
Method = CkJsonObject_stringOf(ljd,"encrypt.method");
CkPdf_Dispose(pdf);
CkJsonObject_Dispose(ljd);
}