(Ruby) Send Encrypted Email with a Selected Algorithm (AES, 3DES, etc.)

Sends an encrypted email using the recipient's digital certificate from a .cer file, and chooses 3DES for the encryption algorithm. (It is also possible to send AES encrypted email w/ 128-bit, 192-bit, or 256-bit encryption simply by setting the Pkcs7CryptAlg and Pkcs7KeyLength properties.)

Chilkat Ruby Downloads install from rubygems.org gem install chilkat or download... Ruby Library for Windows, MacOS, Linux, Alpine Linux

require 'chilkat'

# 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 = Chilkat::CkMailMan.new()

# Set the SMTP server.
mailman.put_SmtpHost("smtp.mymailserver.com")

# Load the .cer file into a certificate object.
# When sending S/MIME encrypted email, it is the recipient's
# certificate that is used for encryption.  Only the public key
# is needed to encrypt.  The recipient is the only
# one possessing the private key, and therefore is the only
# one able to decrypt.
cert = Chilkat::CkCert.new()
success = cert.LoadFromFile("cknotes.cer")
if (success != true)
    print cert.lastErrorText() + "\n";
    exit
end

# Create a new email object
email = Chilkat::CkEmail.new()

email.put_Subject("This email is encrypted")
email.put_Body("This is a digitally encrypted mail")
email.put_From("Chilkat Support <support@chilkatsoft.com>")
success = email.AddTo("Chilkat Blog","admin@cknotes.com")

# Indicate that the email is to be sent encrypted.
email.put_SendEncrypted(true)

# Specify the certificate to be used for encryption.
success = email.SetEncryptCert(cert)

# If desired, specify the encryption algorithm to be used.
# The Pkcs7CryptAlg property can be set to "aes", "des", "3des", or "rc2"
email.put_Pkcs7CryptAlg("3des")

# If desired, set the key length (in bits) for the encryption algorithm:
# The possible values allowed depend on the Pkcs7CryptAlg property. 
# For "aes", the key length may be 128, 192, or 256. 
# For "3des" the key length must be 192. 
# For "des" the key length must be 40. 
# For "rc2" the key length can be 40, 56, 64, or 128.
email.put_Pkcs7KeyLength(192)

success = mailman.SendEmail(email)
if (success != true)
    print mailman.lastErrorText() + "\n";
else
    print "Mail Sent!" + "\n";
end