PHP Requires Chilkat v11.0.0+

Decrypt S/MIME and Verify S/MIME Signatures

See more MIME Examples

_LANGUAGE_ example to decrypt S/MIME and verify S/MIME signatures. The S/MIME is unwrapped to get the original MIME prior to signing/encrypting. Chilkat2 PHP

<?php

use Chilkat2\Cert;
use Chilkat2\Mime;

$success = false;

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

$mime = new Mime();

// Load an S/MIME message from a file:
try {
    $mime->LoadMimeFile('signedMime.txt');
} catch (\Chilkat2\Exception $e) {
    echo $e->getMessage(), "\n";
    exit;
}

// The ContainsEncryptedParts/ContainsSignedParts methods
// can be called to determine if the MIME is encrypted and/or signed:
$isEncrypted = $mime->ContainsEncryptedParts();
$isSigned = $mime->ContainsSignedParts();

// We don't want the "unwrap extras".  You'll see what those
// are in a few moments...
$mime->UnwrapExtras = false;

// To verify the signature, call UnwrapSecurity.  This will
// verify the signature(s) and decrypt the S/MIME and restore
// the MIME to the unsigned/unencrypted state.
// The results of what was found are present in the MIME object's
// properties, as well as extra header fields that are added
// to the unwrapped MIME.
try {
    $mime->UnwrapSecurity();
} catch (\Chilkat2\Exception $e) {
    // UnwrapSecurity returns true if all signatures were
    // verified and all parts decrypted.
    echo $e->getMessage(), "\n";
    exit;
}

// The mime.UnwrapExtras property controls whether or not
// these additional fields are added to the unwrapped MIME:
//
// X-NumPartsSigned: 1
// X-SignaturesValid: yes
// X-NumPartsEncrypted: 1
// X-Decrypted: no
//
// The X-NumPartsSigned/X-SignaturesValid headers are added
// if the MIME was signed.
//
// The X-NumPartsEncrypted/X-Decrypted headers are added
// if the MIME was encrypted.
//

// If the MIME was signed, get the certificate used for signing.
if ($isSigned) {
    $signerCert = new Cert();

    // The NumSignerCerts property indicates how many certificates
    // were used for signing.  This example will assume the value is 1.
    // To get the 1st signer cert, call LastSignerCert with an index of 0:
    try {
        $mime->LastSignerCert(0, $signerCert);
        $success = true;
    } catch (\Chilkat2\Exception $e) {
        $success = false;
    }
    if ($success) {
        echo '**** Signer Cert: ', $signerCert->SubjectCN, "\n";
    }
}

// If the MIME was encrypted, get the certificate used for decryption
if ($isEncrypted) {
    // The NumDecryptCerts property indicates how many certificates
    // were used for decrypting.  This example will assume the value is 1.
    // To get the 1st decrypt cert, call LastDecryptCert with an index of 0:
    $decryptCert = new Cert();
    try {
        $mime->LastDecryptCert(0, $decryptCert);
        $success = true;
    } catch (\Chilkat2\Exception $e) {
        $success = false;
    }
    if ($success) {
        echo '**** Decrypt Cert: ', $decryptCert->SubjectCN, "\n";
    }
}

// Display the unwrapped MIME:
echo $mime->GetMime(), "\n";

// Save the unwrapped MIME to a file:
$mime->SaveMime('unwrappedMime.txt');