Objective-C

Examine Client Certificates for an Accepted TLS Connection

See more Socket/SSL/TLS Examples

Demonstrates how to access the client certificates for a TLS connection accepted by your application acting as the server. Objective-C

#import <CkoSocket.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.

CkoSocket *listenSslSocket = [[CkoSocket alloc] init];

//  An SSL/TLS server needs a digital certificate.  This example loads it from a PFX file.
//  This is the server's certificate.

CkoCert *cert = [[CkoCert alloc] init];
success = [cert LoadPfxFile: @"qa_data/serverCert/myServerCert.pfx" password: @"pfx_password"];
if (success == NO) {
    NSLog(@"%@",cert.LastErrorText);
    return;
}

//  To accept client client certificates in the TLS handshake,
//  we must indicate a list of acceptable client certificate root CA DN's
//  that are allowed.  (DN is an acronym for Distinguished Name.)
//  Call AddSslAcceptableClientCaDn once for each acceptable CA DN.
//  Here are a few examples so you can see the general format of a DN.
[listenSslSocket AddSslAcceptableClientCaDn: @"C=SE, O=AddTrust AB, OU=AddTrust External TTP Network, CN=AddTrust External CA Root"];
[listenSslSocket AddSslAcceptableClientCaDn: @"O=Digital Signature Trust Co., CN=DST Root CA X3"];

//  Initialize with our server's TLS certificate.
success = [listenSslSocket InitSslServer: cert];
if (success == NO) {
    NSLog(@"%@",listenSslSocket.LastErrorText);
    return;
}

//  Bind and listen on a port:
int myPort = 8123;
//  Allow for a max of 5 queued connect requests.
int backLog = 5;
success = [listenSslSocket BindAndListen: [NSNumber numberWithInt: myPort] backlog: [NSNumber numberWithInt: backLog]];
if (success == NO) {
    NSLog(@"%@",listenSslSocket.LastErrorText);
    return;
}

//  Accept the next incoming connection.
int maxWaitMillisec = 20000;

CkoSocket *clientSock = [[CkoSocket alloc] init];
success = [listenSslSocket AcceptNext: [NSNumber numberWithInt: maxWaitMillisec] socket: clientSock];
if (success == NO) {
    NSLog(@"%@",listenSslSocket.LastErrorText);
    return;
}

//  Examine the client certs chain.  The 1st cert will be the client certificate, and
//  the subsequent certs will be the certs in the chain of authentication.
int numClientCerts = [clientSock.NumReceivedClientCerts intValue];
NSLog(@"%@%d",@"numClientCerts = ",numClientCerts);

CkoCert *clientCert = [[CkoCert alloc] init];
int i = 0;
while (i < numClientCerts) {
    [clientSock GetRcvdClientCert: [NSNumber numberWithInt: i] cert: clientCert];
    NSLog(@"%@",clientCert.SubjectDN);
    i = i + 1;
}

//  Close the connection with the client
success = [clientSock Close: [NSNumber numberWithInt: 1000]];