Objective-C

Create JWK Set Containing Certificates

See more Certificates Examples

Demonstrates how to create a JWK Set containing N certificates. Objective-C

#import <CkoCert.h>
#import <CkoCrypt2.h>
#import <CkoJsonObject.h>
#import <NSString.h>
#import <CkoPublicKey.h>

BOOL success = NO;

//  This example creates the following JWK Set from two certificates:

//  {
//    "keys": [
//      {
//        "kty": "RSA",
//        "use": "sig",
//        "kid": "BB8CeFVqyaGrGNuehJIiL4dfjzw",
//        "x5t": "BB8CeFVqyaGrGNuehJIiL4dfjzw",
//        "n": "nYf1jpn7cFdQ...9Iw",
//        "e": "AQAB",
//        "x5c": [
//          "MIIDBTCCAe2...Z+NTZo"
//        ]
//      },
//      {
//        "kty": "RSA",
//        "use": "sig",
//        "kid": "M6pX7RHoraLsprfJeRCjSxuURhc",
//        "x5t": "M6pX7RHoraLsprfJeRCjSxuURhc",
//        "n": "xHScZMPo8F...EO4QQ",
//        "e": "AQAB",
//        "x5c": [
//          "MIIC8TCCAdmgA...Vt5432GA=="
//        ]
//      }
//    ]
//  }

//  First get two certificates from files.
CkoCert *cert1 = [[CkoCert alloc] init];
success = [cert1 LoadFromFile: @"qa_data/certs/brasil_cert.pem"];
if (success == NO) {
    NSLog(@"%@",cert1.LastErrorText);
    return;
}

CkoCert *cert2 = [[CkoCert alloc] init];
success = [cert2 LoadFromFile: @"qa_data/certs/testCert.cer"];
if (success == NO) {
    NSLog(@"%@",cert2.LastErrorText);
    return;
}

//  We'll need this crypt object re-encode the SHA1 thumbprint from hex to base64.
CkoCrypt2 *crypt = [[CkoCrypt2 alloc] init];

CkoJsonObject *json = [[CkoJsonObject alloc] init];

//  Let's begin with the 1st cert:
json.I = [NSNumber numberWithInt:0];
[json UpdateString: @"keys[i].kty" value: @"RSA"];
[json UpdateString: @"keys[i].use" value: @"sig"];

NSString *hexThumbprint = cert1.Sha1Thumbprint;
NSString *base64Thumbprint = [crypt ReEncode: hexThumbprint fromEncoding: @"hex" toEncoding: @"base64"];
[json UpdateString: @"keys[i].kid" value: base64Thumbprint];
[json UpdateString: @"keys[i].x5t" value: base64Thumbprint];

//  (We're assuming these are RSA certificates)
//  To get the modulus (n) and exponent (e), we need to get the cert's public key and then get its JWK.
CkoPublicKey *pubKey = [[CkoPublicKey alloc] init];
[cert1 GetPublicKey: pubKey];

CkoJsonObject *pubKeyJwk = [[CkoJsonObject alloc] init];
[pubKeyJwk Load: [pubKey GetJwk]];
[json UpdateString: @"keys[i].n" value: [pubKeyJwk StringOf: @"n"]];
[json UpdateString: @"keys[i].e" value: [pubKeyJwk StringOf: @"e"]];

//  Now add the entire X.509 certificate 
[json UpdateString: @"keys[i].x5c[0]" value: [cert1 GetEncoded]];

//  Now do the same for cert2..
json.I = [NSNumber numberWithInt:1];

[json UpdateString: @"keys[i].kty" value: @"RSA"];
[json UpdateString: @"keys[i].use" value: @"sig"];

hexThumbprint = cert2.Sha1Thumbprint;
base64Thumbprint = [crypt ReEncode: hexThumbprint fromEncoding: @"hex" toEncoding: @"base64"];
[json UpdateString: @"keys[i].kid" value: base64Thumbprint];
[json UpdateString: @"keys[i].x5t" value: base64Thumbprint];
[cert2 GetPublicKey: pubKey];

[pubKeyJwk Load: [pubKey GetJwk]];
[json UpdateString: @"keys[i].n" value: [pubKeyJwk StringOf: @"n"]];
[json UpdateString: @"keys[i].e" value: [pubKeyJwk StringOf: @"e"]];

//  Now add the entire X.509 certificate 
[json UpdateString: @"keys[i].x5c[0]" value: [cert2 GetEncoded]];

//  Emit the JSON..
json.EmitCompact = NO;
NSLog(@"%@",[json Emit]);