Tcl
Tcl
Select the S/MIME Encryption Algorithm
See more Email Object Examples
Demonstrates the Chilkat Email.Pkcs7CryptAlg property, which selects the underlying symmetric encryption algorithm used when an email is sent encrypted with PKCS#7 public-key (S/MIME) encryption. Possible values are aes, aes-gcm, des, 3des, and rc2; the default is aes. This example selects AES and pairs it with a 256-bit key length.
Background: S/MIME encryption is hybrid. The message body is encrypted with a fast symmetric algorithm (the one this property chooses, such as AES) using a randomly generated one-time key; then that one-time key is itself encrypted with each recipient's public key. This gives the speed of symmetric encryption with the key-distribution convenience of public-key cryptography. Modern choices like
aes are strongly preferred — older options such as des and rc2 are considered weak.Chilkat Tcl Downloads
load ./chilkat.dll
# Demonstrates the Email.Pkcs7CryptAlg property, which selects the symmetric encryption
# algorithm used when an email is sent encrypted with PKCS#7 (S/MIME) public-key
# encryption. Possible values: aes, aes-gcm, des, 3des, rc2. The default is aes.
set email [new_CkEmail]
CkEmail_put_Subject $email "Encrypted email"
CkEmail_put_Body $email "This message will be S/MIME encrypted when sent."
# Select AES with a 256-bit key for the symmetric encryption.
CkEmail_put_Pkcs7CryptAlg $email "aes"
CkEmail_put_Pkcs7KeyLength $email 256
puts "Pkcs7CryptAlg = [CkEmail_pkcs7CryptAlg $email]"
puts "Pkcs7KeyLength = [CkEmail_get_Pkcs7KeyLength $email]"
delete_CkEmail $email