Tcl

S/MIME Encrypt .eml without Sending

See more Email Object Examples

Demonstrates how to encrypt an email using the recipient's digital certificate. This example just encrypts, and does not send the email. Tcl

load ./chilkat.dll

set success 0

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

set email [new_CkEmail]

set success [CkEmail_LoadEml $email "c:/temp/email/unencrypted.eml"]
if {$success == 0} then {
    puts [CkEmail_lastErrorText $email]
    delete_CkEmail $email
    exit
}

# The email content is encrypted using AES with a 256-bit key, operating in GCM mode, which provides authenticated encryption.
CkEmail_put_Pkcs7CryptAlg $email "aes-gcm"
CkEmail_put_Pkcs7KeyLength $email 256
CkEmail_put_OaepPadding $email 1
CkEmail_put_OaepHash $email "sha256"
CkEmail_put_OaepMgfHash $email "sha256"

set cert [new_CkCert]

set success [CkCert_LoadFromFile $cert "c/temps/cert/recipient.cer"]
if {$success == 0} then {
    puts [CkCert_lastErrorText $cert]
    delete_CkEmail $email
    delete_CkCert $cert
    exit
}

CkEmail_put_SendEncrypted $email 1
CkEmail_SetEncryptCert $email $cert

set sbSmime [new_CkStringBuilder]

# 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.
set mailman [new_CkMailMan]

set success [CkMailMan_RenderToMimeSb $mailman $email $sbSmime]
if {$success == 0} then {
    puts [CkMailMan_lastErrorText $mailman]
    delete_CkEmail $email
    delete_CkCert $cert
    delete_CkStringBuilder $sbSmime
    delete_CkMailMan $mailman
    exit
}

set success [CkStringBuilder_WriteFile $sbSmime "c:/temp/encryptedEmail.eml" "utf-8" 0]
if {$success == 0} then {
    puts [CkMailMan_lastErrorText $mailman]
    delete_CkEmail $email
    delete_CkCert $cert
    delete_CkStringBuilder $sbSmime
    delete_CkMailMan $mailman
    exit
}

puts "Success!"

delete_CkEmail $email
delete_CkCert $cert
delete_CkStringBuilder $sbSmime
delete_CkMailMan $mailman