(Objective-C) Get PDF Signer Certs

See more PDF Signatures Examples

This example demonstrates how to validate the signatures in a PDF and also shows how to get each signature's signer certificate.

Note: This example requires Chilkat v9.5.0.87 or greater.

Chilkat Objective-C Library Downloads MAC OS X (Cocoa) Libs iOS Libs

#import <CkoPdf.h>
#import <CkoJsonObject.h>
#import <CkoCert.h>

// This example requires the Chilkat API to have been previously unlocked.
// See Global Unlock Sample for sample code.

CkoPdf *pdf = [[CkoPdf alloc] init];

// Load a PDF that has cryptographic signatures to be validated
BOOL success = [pdf LoadFile: @"qa_data/pdf/sign_testing_1/helloSigned2.pdf"];
if (success == NO) {
    NSLog(@"%@",pdf.LastErrorText);
    return;
}

// Each time we verify a signature, information about the signature is written into
// sigInfo (replacing whatever sigInfo previously contained).
CkoJsonObject *sigInfo = [[CkoJsonObject alloc] init];

// Iterate over each signature and validate each.
int numSignatures = [pdf.NumSignatures intValue];
BOOL validated = NO;
CkoCert *cert = [[CkoCert alloc] init];
int i = 0;
while (i < numSignatures) {
    validated = [pdf VerifySignature: [NSNumber numberWithInt: i] sigInfo: sigInfo];
    NSLog(@"%@%d%@%d",@"Signature ",i,@" validated: ",validated);

    // The GetSignerCert method was added in Chilkat v9.5.0.87
    // After calling VerifySignature, you can get the signer certificate by calling
    // GetSignerCert with the same index. 
    success = [pdf GetSignerCert: [NSNumber numberWithInt: i] cert: cert];
    if (success != NO) {
        NSLog(@"%@%@",@"PDF signer certificate: ",cert.SubjectDN);
    }

    i = i + 1;
}

NSLog(@"%@",@"Finished.");