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Duplicate openssl smime -decrypt -in some_file.dat.enc -binary -inform DER -inkey private.key -out some_file.dat

See more OpenSSL Examples

Demonstrates how to decrypt binary DER that was encrypted using the following openssl command:
openssl smime -encrypt -binary -aes-256-cbc -in some_file.dat -out some_file.dat.enc -outform DER cert.crt

Chilkat PHP Extension Downloads

PHP Extension
<?php

include("chilkat.php");

$success = false;

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

// Duplicates the following openssl command:
// openssl smime -decrypt -in hello.txt.enc -binary -inform DER -inkey private.key -out hello.txt

$cert = new CkCert();
$success = $cert->LoadFromFile('qa_data/openssl/EE.cer');
if ($success == false) {
    print $cert->lastErrorText() . "\n";
    exit;
}

$bd = new CkBinData();
$success = $bd->LoadFile('qa_data/openssl/EE.key');
// Assuming success..

$privKey = new CkPrivateKey();
$success = $privKey->LoadAnyFormat($bd,'');
if ($success == false) {
    print $privKey->lastErrorText() . "\n";
    exit;
}

$crypt = new CkCrypt2();
$success = $crypt->SetDecryptCert2($cert,$privKey);
if ($success == false) {
    print $crypt->lastErrorText() . "\n";
    exit;
}

$crypt->put_CryptAlgorithm('PKI');
$success = $crypt->CkDecryptFile('qa_data/openssl/hello.txt.enc','qa_output/hello.txt');
if ($success == false) {
    print $crypt->lastErrorText() . "\n";
    exit;
}

print 'Success.' . "\n";

?>