Encrypt a JWE with a Symmetric Wrapping Key

See more JSON Web Encryption (JWE) Examples

Demonstrates Jwe.SetWrappingKey, which sets the symmetric key-wrapping key for a recipient. The key bytes are supplied in a named encoding such as hex or base64.

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

BOOL success = NO;

CkoJwe *jwe = [[CkoJwe alloc] init];

//  Protected header: AES key-wrap with AES-256-GCM content encryption.
CkoJsonObject *header = [[CkoJsonObject alloc] init];
[header UpdateString: @"alg" value: @"A256KW"];
[header UpdateString: @"enc" value: @"A256GCM"];
success = [jwe SetProtectedHeader: header];
if (success == NO) {
    NSLog(@"%@",jwe.LastErrorText);
    return;
}

//  Set the symmetric key-wrapping key for recipient 0.  The key bytes are provided in the named
//  encoding (here base64).  In production, obtain the key from a secure source rather than hard-coding
//  it.
NSString *base64Key = @"YWJjZGVmZ2hpamtsbW5vcHFyc3R1dnd4eXowMTIzNDU=";
success = [jwe SetWrappingKey: [NSNumber numberWithInt: 0] encodedKey: base64Key encoding: @"base64"];
if (success == NO) {
    NSLog(@"%@",jwe.LastErrorText);
    return;
}

NSString *jweCompact = [jwe Encrypt: @"This is the secret content." charset: @"utf-8"];
if (jwe.LastMethodSuccess == NO) {
    NSLog(@"%@",jwe.LastErrorText);
    return;
}

NSLog(@"%@",jweCompact);