Objective-C

Examine KeyInfo Certificate in XML Signature

See more XML Digital Signatures Examples

This example loads signed XML and gets the signing certificate, assuming the certificate is contained in X509Certificate within the KeyInfo. Objective-C

#import <CkoXmlDSig.h>
#import <CkoStringBuilder.h>
#import <CkoXml.h>
#import <NSString.h>
#import <CkoCert.h>

BOOL success = NO;

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

CkoXmlDSig *dsig = [[CkoXmlDSig alloc] init];
CkoStringBuilder *sbXml = [[CkoStringBuilder alloc] init];

success = [sbXml LoadFile: @"c:/aaworkarea/elias/3/face_f09006808443a699d1b.xml" charset: @"utf-8"];
if (success != YES) {
    NSLog(@"%@",@"Failed to load XML file.");
    return;
}

success = [dsig LoadSignatureSb: sbXml];
if (success != YES) {
    NSLog(@"%@",dsig.LastErrorText);
    return;
}

// Get the KeyInfo XML.
CkoXml *xmlKeyInfo = [dsig GetKeyInfo];
if (dsig.LastMethodSuccess != YES) {
    NSLog(@"%@",dsig.LastErrorText);
    return;
}

NSLog(@"%@",[xmlKeyInfo GetXml]);
NSLog(@"%@",@"----");

// Assuming the X509Certificate is in the KeyInfo, it will look like this:

//   <ds:KeyInfo Id="...">
//     <ds:KeyValue>
//     ...  
//     <ds:X509Data>
//       <ds:X509Certificate>MIIHAz...</ds:X509Certificate>
//     </ds:X509Data>
//   </ds:KeyInfo>
NSString *certBase64 = [xmlKeyInfo GetChildContent: @"*:X509Data|*:X509Certificate"];
if (xmlKeyInfo.LastMethodSuccess != YES) {
    NSLog(@"%@",@"No X509Certificate found in the KeyInfo.");
    return;
}

// Load a certificate object w/ the base64.
CkoCert *cert = [[CkoCert alloc] init];
success = [cert LoadFromBase64: certBase64];
if (success != YES) {
    NSLog(@"%@",cert.LastErrorText);
    return;
}

// Examine the cert..
NSLog(@"%@%@",@"SubjectDN: ",cert.SubjectDN);
NSLog(@"%@%@",@"IssuerDN: ",cert.IssuerDN);
NSLog(@"%@%@",@"SerialNumber as Decimal: ",cert.SerialDecimal);