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C

Send aes-gcm authEnvelopedData Encrypted Email

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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.

Chilkat C Downloads

C
#include <C_CkMailMan.h>
#include <C_CkCert.h>
#include <C_CkEmail.h>

void ChilkatSample(void)
    {
    BOOL success;
    HCkMailMan mailman;
    HCkCert cert;
    HCkEmail email;

    success = FALSE;

    // 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.
    mailman = CkMailMan_Create();

    CkMailMan_putSmtpHost(mailman,"smtp.example.com");

    CkMailMan_putSmtpUsername(mailman,"my_smtp_login");
    CkMailMan_putSmtpPassword(mailman,"my_smtp_password");

    // The typical SMTP ports are 465 for implicit SSL/TLS or 587 for explicit SSL/TLS
    CkMailMan_putSmtpPort(mailman,465);
    CkMailMan_putSmtpSsl(mailman,TRUE);

    // Use the recipient's certificate for encryption.
    cert = CkCert_Create();
    success = CkCert_LoadFromFile(cert,"c:/someDir/recipient_cert.cer");
    if (success != TRUE) {
        printf("%s\n",CkCert_lastErrorText(cert));
        CkMailMan_Dispose(mailman);
        CkCert_Dispose(cert);
        return;
    }

    email = CkEmail_Create();

    CkEmail_putSubject(email,"This email is encrypted");
    CkEmail_putBody(email,"This is AES-GCM encrypted mail");
    CkEmail_putFrom(email,"Mary <mary@example1.com>");
    success = CkEmail_AddTo(email,"Joe","joe@example.com");

    // Specify that AES-GCM w/ authEnvelopedData is to be used. 
    // Also specify other params..
    CkEmail_putPkcs7CryptAlg(email,"aes-gcm");
    CkEmail_putPkcs7KeyLength(email,128);
    CkEmail_putOaepPadding(email,TRUE);
    CkEmail_putOaepHash(email,"sha256");
    CkEmail_putOaepMgfHash(email,"sha256");

    // Indicate the email is to be sent encrypted.
    CkEmail_putSendEncrypted(email,TRUE);

    // Specify the certificate to be used for encryption.
    success = CkEmail_SetEncryptCert(email,cert);

    success = CkMailMan_SendEmail(mailman,email);
    if (success != TRUE) {
        printf("%s\n",CkMailMan_lastErrorText(mailman));
    }
    else {
        printf("Mail Sent!\n");
    }



    CkMailMan_Dispose(mailman);
    CkCert_Dispose(cert);
    CkEmail_Dispose(email);

    }