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PHP Extension

Decrypt S/MIME using a Certificate with Private Key Access

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Loads a CMS/PKCS #7 encrypted S/MIME message and decrypts it back to the original MIME content.

DecryptUsingCert takes a single certificate that already has access to its associated private key, for example a certificate loaded from a PFX.

The file paths are relative to the application's current working directory. Absolute paths may also be used. Supply the paths appropriate to your own environment.

Background. A public-only certificate is insufficient for decryption. The certificate passed to DecryptUsingCert must be linked to its private key, as happens when it is loaded from a PFX/P12 file.

Chilkat PHP Extension Downloads

PHP Extension
<?php

include("chilkat.php");

$success = false;

$mime = new CkMime();
$success = $mime->LoadMimeFile('qa_data/encrypted.eml');
if ($success == false) {
    print $mime->lastErrorText() . "\n";
    exit;
}

//  Decrypt using a certificate that already provides access to its private key (for example loaded
//  from a PFX).  The only argument is the certificate.
$pfxPassword = 'myPfxPassword';
$cert = new CkCert();
$success = $cert->LoadPfxFile('qa_data/recipient.pfx',$pfxPassword);
if ($success == false) {
    print $cert->lastErrorText() . "\n";
    exit;
}

$success = $mime->DecryptUsingCert($cert);
if ($success == false) {
    print $mime->lastErrorText() . "\n";
    exit;
}

$body = $mime->getBodyDecoded();
if ($mime->get_LastMethodSuccess() == false) {
    print $mime->lastErrorText() . "\n";
    exit;
}

print $body . "\n";

?>