Objective-C

Load ECC Private Key from JWK Format (JSON Web Key)

See more ECC Examples

Demonstrates how to load an ECC private key from JWK (JSON Web Key) format.

Note: This example requires Chilkat v9.5.0.66 or later.

Objective-C

#import <CkoJsonObject.h>
#import <NSString.h>
#import <CkoPrivateKey.h>

BOOL success = NO;

//  Note: This example requires Chilkat v9.5.0.66 or later.

//  First build a JWK sample to load..
CkoJsonObject *json = [[CkoJsonObject alloc] init];
[json UpdateString: @"kty" value: @"EC"];
[json UpdateString: @"crv" value: @"P-256"];
[json UpdateString: @"x" value: @"oBUyo8CQAFPeYPvv78ylh5MwFZjTCLQeb042TjiMJxE"];
[json UpdateString: @"y" value: @"vvQyxZkUjJQUPU_0bCy3Pj5qQdfu8jwEfqEeYGZ95CU"];
[json UpdateString: @"d" value: @"EbVzfPnZPxfAyxqEZV05laAoJAl-_6Xt2O4mOB611sM"];

//  The JSON contains the following:
//  { 
//    "kty": "EC",
//    "crv": "P-256",
//    "x": "oBUyo8CQAFPeYPvv78ylh5MwFZjTCLQeb042TjiMJxE",
//    "y": "vvQyxZkUjJQUPU_0bCy3Pj5qQdfu8jwEfqEeYGZ95CU",
//    "d": "EbVzfPnZPxfAyxqEZV05laAoJAl-_6Xt2O4mOB611sM"
//  }

//  Note: The JSON can contain other members, such as "use", "kid", or anything else.  These will be ignored.
json.EmitCompact = NO;

//  Show the JWK string to be loaded:
NSString *jwkStr = [json Emit];

CkoPrivateKey *privKey = [[CkoPrivateKey alloc] init];
success = [privKey LoadJwk: jwkStr];
if (success != YES) {
    NSLog(@"%@",privKey.LastErrorText);
    return;
}

//  OK.. the JWK is loaded.  It can be used in whatever way desired...

//  The key can be retrieved in any other format, such as XML or PEM..
NSLog(@"%@",[privKey GetXml]);

//  XML output:
//  <ECCKeyValue curve="secp256r1">MHcCAQEEIBG1c3z52T8XwMsahGVdOZWgKCQJfv+l7djuJjgetdbDoAoGCCqGSM49AwEHoEQDQgAEoBUyo8CQAFPeYPvv78ylh5MwFZjTCLQeb042TjiMJxG+9DLFmRSMlBQ9T/RsLLc+PmpB1+7yPAR+oR5gZn3kJQ==</ECCKeyValue>

NSLog(@"%@",[privKey GetPkcs8EncryptedPem: @"secret"]);

//  PEM output
//  
//  -----BEGIN ENCRYPTED PRIVATE KEY-----
//  MIHFMEAGCSqGSIb3DQEFDTAzMBsGCSqGSIb3DQEFDDAOBAiku9rUjavLQQICCAAw
//  FAYIKoZIhvcNAwcECGsl/5nLai+JBIGAVIqKAdfcRQNLl1t3x+n8OZ92d1H+qgjS
//  Hs83wn2joJK4nlqy+rzosZxQ3e8NTJQyUEWZWcjqMj/N0phS3QWtcD/qbda5oEcv
//  QgtU60cZ4ql3truefAmlZz2PdpOfqtYhxlvjJQxnyojn4ntj69OwLOt9SZbaBQQi
//  KUL8KXT4Pq8=
//  -----END ENCRYPTED PRIVATE KEY-----