Objective-C

Send aes-gcm authEnvelopedData Encrypted Email

See more SMTP Examples

Note: This example requires Chilkat v10.0.0 or later

Demonstrates how to send encrypted email using 128-bit AES in GCM mode.

"AES-GCM" (Advanced Encryption Standard - Galois/Counter Mode) is a cryptographic algorithm that provides both encryption and integrity protection (authentication). When used in the context of email security with "authEnvelopedData", it often refers to a method of securely sending encrypted and authenticated email content.

Here’s a brief breakdown:

• AES-GCM: Combines symmetric encryption (AES) with authentication, ensuring both the confidentiality and integrity of the message. It generates an authentication tag to detect any unauthorized changes.
• authEnvelopedData: Refers to a type of structure used in secure email protocols (like S/MIME) to package encrypted content. It contains the encrypted data and associated encrypted session keys.
• Email Security: When applied to emails, AES-GCM ensures the email content is encrypted (confidential) and also tamper-resistant (authenticated), with the encryption keys typically shared securely using asymmetric encryption (e.g., public key infrastructure, or PKI).

In short, AES-GCM with "authEnvelopedData" provides a way to encrypt and authenticate emails, making them confidential and resistant to tampering.

Objective-C

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

BOOL success = NO;

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

// The mailman object is used for sending and receiving email.
CkoMailMan *mailman = [[CkoMailMan alloc] init];

mailman.SmtpHost = @"smtp.example.com";

mailman.SmtpUsername = @"my_smtp_login";
mailman.SmtpPassword = @"my_smtp_password";

// The typical SMTP ports are 465 for implicit SSL/TLS or 587 for explicit SSL/TLS
mailman.SmtpPort = [NSNumber numberWithInt:465];
mailman.SmtpSsl = YES;

// Use the recipient's certificate for encryption.
CkoCert *cert = [[CkoCert alloc] init];
success = [cert LoadFromFile: @"c:/someDir/recipient_cert.cer"];
if (success != YES) {
    NSLog(@"%@",cert.LastErrorText);
    return;
}

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

email.Subject = @"This email is encrypted";
email.Body = @"This is AES-GCM encrypted mail";
email.From = @"Mary <mary@example1.com>";
success = [email AddTo: @"Joe" emailAddress: @"joe@example.com"];

// Specify that AES-GCM w/ authEnvelopedData is to be used. 
// Also specify other params..
email.Pkcs7CryptAlg = @"aes-gcm";
email.Pkcs7KeyLength = [NSNumber numberWithInt:128];
email.OaepPadding = YES;
email.OaepHash = @"sha256";
email.OaepMgfHash = @"sha256";

// Indicate the email is to be sent encrypted.
email.SendEncrypted = YES;

// Specify the certificate to be used for encryption.
success = [email SetEncryptCert: cert];

success = [mailman SendEmail: email];
if (success != YES) {
    NSLog(@"%@",mailman.LastErrorText);
}
else {
    NSLog(@"%@",@"Mail Sent!");
}