Ruby

Load .eml and Decrypt (smime.p7m)

Loads an encrypted email from a .eml file and decrypts using certificate w/ private key found in a .p12 (or .pfx) file.

The Content-Type and Content-Disposition email headers of the email to be decrypted look similar to this:

Content-Type: application/x-pkcs7-mime; smime-type=enveloped-data;
	name="smime.p7m"
Content-Disposition: attachment; filename="smime.p7m"

Ruby

require 'chilkat'

success = false

email = Chilkat::CkEmail.new()

# Add a PFX (or .p12) to be used for decryption
success = email.AddPfxSourceFile("myCert.p12","passwordForP12")
if (success != true)
    print email.lastErrorText() + "\n";
    exit
end

# Loading the .eml automatically decrypts.
success = email.LoadEml("encrypted.eml")
if (success != true)
    print email.lastErrorText() + "\n";
    exit
end

# The email now exists as it was prior to encryption.
# Your app may access the email's subject, body, attachments,
# etc. using the Chilkat Email API...

# Save the decrypted email:
success = email.SaveEml("decrypted.eml")
if (success != true)
    print email.lastErrorText() + "\n";
    exit
end

print "Success." + "\n";