(Objective-C) S/MIME Encrypt .eml without Sending

See more Email Object Examples

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

#import <CkoEmail.h>
#import <CkoCert.h>
#import <CkoStringBuilder.h>
#import <CkoMailMan.h>

BOOL success = NO;

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

CkoEmail *email = [[CkoEmail alloc] init];

success = [email LoadEml: @"c:/temp/email/unencrypted.eml"];
if (success == NO) {
    NSLog(@"%@",email.LastErrorText);
    return;
}

// The email content is encrypted using AES with a 256-bit key, operating in GCM mode, which provides authenticated encryption.
email.Pkcs7CryptAlg = @"aes-gcm";
email.Pkcs7KeyLength = [NSNumber numberWithInt:256];
email.OaepPadding = YES;
email.OaepHash = @"sha256";
email.OaepMgfHash = @"sha256";

CkoCert *cert = [[CkoCert alloc] init];
success = [cert LoadFromFile: @"c/temps/cert/recipient.cer"];
if (success == NO) {
    NSLog(@"%@",cert.LastErrorText);
    return;
}

email.SendEncrypted = YES;
[email SetEncryptCert: cert];

CkoStringBuilder *sbSmime = [[CkoStringBuilder alloc] init];

// The mailman object applies the encryption by rendering the email according to the instructions (property settings) provided in the email object.
// No email is sent.
CkoMailMan *mailman = [[CkoMailMan alloc] init];
success = [mailman RenderToMimeSb: email renderedMime: sbSmime];
if (success == NO) {
    NSLog(@"%@",mailman.LastErrorText);
    return;
}

success = [sbSmime WriteFile: @"c:/temp/encryptedEmail.eml" charset: @"utf-8" emitBom: NO];
if (success == NO) {
    NSLog(@"%@",mailman.LastErrorText);
    return;
}

NSLog(@"%@",@"Success!");