Perl

Encrypt a File to a PKCS7 (CMS) Message

Shows how to encrypt a file into a PKCS7 encrypted message using the recipient's certificate. Public-key encryption requires no private key. However, the recipient's private key is necessary for decryption. Chilkat2 Perl

use strict;
use warnings;
use Chilkat2;

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

my $crypt = Chilkat2::Crypt2->new;

# Load the recipient's digital certificate.
# We don't need the private key for encryption.
# Only the public key is needed (which is included in a certificate).
my $cert1 = Chilkat2::Cert->new;
my $success = $cert1->LoadFromFile('qa_data/user1/cert_user1.pem');
# Assume success for the example, but make sure your application checks for success/failure...
$crypt->SetEncryptCert($cert1);

# Indicate that we want PKI encryption (i.e. public-key infrastructure)
# to produce a CMS message (Cryptographic Message Syntax/PKCS7),
# that is be created with RSAES-OAEP padding, SHA256, and AES-256 for the
# bulk encryption.
$crypt->CryptAlgorithm('pki');
$crypt->Pkcs7CryptAlg('aes');
$crypt->KeyLength(256);
$crypt->OaepHash('sha256');
$crypt->OaepPadding(1);

# Load the file to be encrypted...
my $fileData = Chilkat2::BinData->new;
$success = $fileData->LoadFile('qa_data/jpg/penguins.jpg');
# Your app should check for success/failure..

# Encrypt the data.  The contents of the fileData object are replaced with the PKCS7 encrypted message.
$success = $crypt->EncryptBd($fileData);
if (!$success) {
    print $crypt->LastErrorText, "\n";
    exit;
}

# Save the PKCS7 encrypted message to a file..
$success = $fileData->WriteFile('qa_output/pkcs7_encrypted.p7');

print "OK.\n";