(Objective-C) Generate a CSR containing an Extension Request

See more CSR Examples

Demonstrates how to generate a CSR containing a 1.2.840.113549.1.9.14 extensionRequest.

Note: This example requires Chilkat v9.5.0.91 or greater.

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

#import <CkoEcc.h>
#import <CkoPrng.h>
#import <CkoPrivateKey.h>
#import <CkoCsr.h>
#import <CkoXml.h>
#import <NSString.h>

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

// This example will generate a secp256r1 ECDSA key for the CSR.
CkoEcc *ecc = [[CkoEcc alloc] init];
CkoPrng *prng = [[CkoPrng alloc] init];

CkoPrivateKey *privKey = [ecc GenEccKey: @"secp256r1" prng: prng];
if (ecc.LastMethodSuccess == NO) {
    NSLog(@"%@",@"Failed to generate a new ECDSA private key.");
    return;
}

CkoCsr *csr = [[CkoCsr alloc] init];

// Add common CSR fields:
csr.CommonName = @"mysubdomain.mydomain.com";
csr.Country = @"GB";
csr.State = @"Yorks";
csr.Locality = @"York";
csr.Company = @"Internet Widgits Pty Ltd";
csr.EmailAddress = @"support@mydomain.com";

// Add the following 1.2.840.113549.1.9.14 extensionRequest
// Note: The easiest way to know the content and format of the XML to be added is to examine
// a pre-existing CSR with the same desired extensionRequest.  You can use Chilkat to
// get the extensionRequest from an existing CSR. 

// 
// Here is a sample extension request:

// <?xml version="1.0" encoding="utf-8"?>
// <set>
//    <sequence>
//        <sequence>
//            <oid>1.3.6.1.4.1.311.20.2</oid>
//            <asnOctets>
//                <printable>ZATCA-Code-Signing</printable>
//            </asnOctets>
//        </sequence>
//        <sequence>
//            <oid>2.5.29.17</oid>
//            <asnOctets>
//                <sequence>
//                    <contextSpecific tag="4" constructed="1">
//                        <sequence>
//                            <set>
//                                <sequence>
//                                    <oid>2.5.4.4</oid>
//                                    <utf8>334623324234325</utf8>
//                                </sequence>
//                            </set>
//                            <set>
//                                <sequence>
//                                    <oid>0.9.2342.19200300.100.1.1</oid>
//                                    <utf8>310122393500003</utf8>
//                                </sequence>
//                            </set>
//                            <set>
//                                <sequence>
//                                    <oid>2.5.4.12</oid>
//                                    <utf8>0000</utf8>
//                                </sequence>
//                            </set>
//                            <set>
//                                <sequence>
//                                    <oid>2.5.4.26</oid>
//                                    <utf8>Sample E</utf8>
//                                </sequence>
//                            </set>
//                            <set>
//                                <sequence>
//                                    <oid>2.5.4.15</oid>
//                                    <utf8>Sample Business</utf8>
//                                </sequence>
//                            </set>
//                        </sequence>
//                    </contextSpecific>
//                </sequence>
//            </asnOctets>
//        </sequence>
//    </sequence>
// </set>

// Use this online tool to generate code from sample XML: 
// Generate Code to Create XML

// Here's the code to generate the above extension request.

CkoXml *xml = [[CkoXml alloc] init];
xml.Tag = @"set";
[xml UpdateChildContent: @"sequence|sequence|oid" value: @"1.3.6.1.4.1.311.20.2"];
[xml UpdateChildContent: @"sequence|sequence|asnOctets|printable" value: @"ZATCA-Code-Signing"];
[xml UpdateChildContent: @"sequence|sequence[1]|oid" value: @"2.5.29.17"];
[xml UpdateAttrAt: @"sequence|sequence[1]|asnOctets|sequence|contextSpecific" autoCreate: YES attrName: @"tag" attrValue: @"4"];
[xml UpdateAttrAt: @"sequence|sequence[1]|asnOctets|sequence|contextSpecific" autoCreate: YES attrName: @"constructed" attrValue: @"1"];
[xml UpdateChildContent: @"sequence|sequence[1]|asnOctets|sequence|contextSpecific|sequence|set|sequence|oid" value: @"2.5.4.4"];
[xml UpdateChildContent: @"sequence|sequence[1]|asnOctets|sequence|contextSpecific|sequence|set|sequence|utf8" value: @"334623324234325"];
[xml UpdateChildContent: @"sequence|sequence[1]|asnOctets|sequence|contextSpecific|sequence|set[1]|sequence|oid" value: @"0.9.2342.19200300.100.1.1"];
[xml UpdateChildContent: @"sequence|sequence[1]|asnOctets|sequence|contextSpecific|sequence|set[1]|sequence|utf8" value: @"310122393500003"];
[xml UpdateChildContent: @"sequence|sequence[1]|asnOctets|sequence|contextSpecific|sequence|set[2]|sequence|oid" value: @"2.5.4.12"];
[xml UpdateChildContent: @"sequence|sequence[1]|asnOctets|sequence|contextSpecific|sequence|set[2]|sequence|utf8" value: @"0000"];
[xml UpdateChildContent: @"sequence|sequence[1]|asnOctets|sequence|contextSpecific|sequence|set[3]|sequence|oid" value: @"2.5.4.26"];
[xml UpdateChildContent: @"sequence|sequence[1]|asnOctets|sequence|contextSpecific|sequence|set[3]|sequence|utf8" value: @"Sample E"];
[xml UpdateChildContent: @"sequence|sequence[1]|asnOctets|sequence|contextSpecific|sequence|set[4]|sequence|oid" value: @"2.5.4.15"];
[xml UpdateChildContent: @"sequence|sequence[1]|asnOctets|sequence|contextSpecific|sequence|set[4]|sequence|utf8" value: @"Sample Business"];

// Add the extension request to the CSR
[csr SetExtensionRequest: xml];

// Generate the CSR with the extension request
NSString *csrPem = [csr GenCsrPem: privKey];
if (csr.LastMethodSuccess == NO) {
    NSLog(@"%@",csr.LastErrorText);

    return;
}

NSLog(@"%@",csrPem);

// Sample PEM output:

// -----BEGIN CERTIFICATE REQUEST-----
// MIICEjCCAbkCAQAwgZcxITAfBgNVBAMMGG15c3ViZG9tYWluLm15ZG9tYWluLmNv
// bTELMAkGA1UEBhMCR0IxDjAMBgNVBAgMBVlvcmtzMQ0wCwYDVQQHDARZb3JrMSEw
// HwYDVQQKDBhJbnRlcm5ldCBXaWRnaXRzIFB0eSBMdGQxIzAhBgkqhkiG9w0BCQEW
// FHN1cHBvcnRAbXlkb21haW4uY29tMFkwEwYHKoZIzj0CAQYIKoZIzj0DAQcDQgAE
// g8EVNSV0ttlM9kG2E+J3ZB9WEDYVf2QA/8idrPRUafia1CHjd1kslwZA8eP2bAcf
// 2O493QAENqtW6DTHJbRz8KCBvjCBuwYJKoZIhvcNAQkOMYGtMIGqMCEGCSsGAQQB
// gjcUAgQUExJaQVRDQS1Db2RlLVNpZ25pbmcwgYQGA1UdEQR9MHukeTB3MRgwFgYD
// VQQEDA8zMzQ2MjMzMjQyMzQzMjUxHzAdBgoJkiaJk/IsZAEBDA8zMTAxMjIzOTM1
// MDAwMDMxDTALBgNVBAwMBDAwMDAxETAPBgNVBBoMCFNhbXBsZSBFMRgwFgYDVQQP
// DA9TYW1wbGUgQnVzaW5lc3MwCgYIKoZIzj0EAwIDRwAwRAIgF7D30eSBklfo+oel
// 1B0z64eJDB9MB3rCoiFZlj+mz0YCIHYI87eyqdtw2LOcAoBRhyxlBT6i28+Z/8t9
// bYsMIYvp
// -----END CERTIFICATE REQUEST-----