Decrypt a JWE into a StringBuilder

See more JSON Web Encryption (JWE) Examples

Demonstrates Jwe.DecryptSb, which decrypts a recipient of a loaded JWE and writes the plaintext into a StringBuilder.

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

BOOL success = NO;

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

//  Load the JWE compact serialization to be decrypted.
NSString *jweCompact = @"eyJhbGciOiJBMjU2S1ciLCJlbmMiOiJBMjU2R0NNIn0.<...>.<iv>.<ciphertext>.<tag>";
success = [jwe LoadJwe: jweCompact];
if (success == NO) {
    NSLog(@"%@",jwe.LastErrorText);
    return;
}

//  The 256-bit key-wrapping key (base64) for recipient index 0.  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;
}

//  Decrypt recipient index 0, writing the plaintext into a StringBuilder.
CkoStringBuilder *sbContent = [[CkoStringBuilder alloc] init];
success = [jwe DecryptSb: [NSNumber numberWithInt: 0] charset: @"utf-8" contentSb: sbContent];
if (success == NO) {
    NSLog(@"%@",jwe.LastErrorText);
    return;
}

NSLog(@"%@",[sbContent GetAsString]);