Perl

Add a Detached Signature (Separate Key, Header Control)

Demonstrates the Chilkat Mime.AddDetachedSignaturePk2 method, which creates a detached signature with a separately supplied certificate and private key, and a third argument controlling transfer of the existing message header fields to the new outer entity.

Note: 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: This combines the two variations — certificate and key supplied separately, plus explicit header placement — for the case that needs both. It is the most flexible of the detached-signature methods; choose it when your key material is separate and you also care about where the message headers end up on the signed result.

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Perl

use chilkat();

$success = 0;

$mime = chilkat::CkMime->new();
$success = $mime->SetBodyFromPlainText("This message will be signed.");
if ($success == 0) {
    print $mime->lastErrorText() . "\r\n";
    exit;
}

#  Load the certificate and its private key separately.
$cert = chilkat::CkCert->new();
$success = $cert->LoadFromFile("qa_data/signer.cer");
if ($success == 0) {
    print $cert->lastErrorText() . "\r\n";
    exit;
}

$privKey = chilkat::CkPrivateKey->new();
$success = $privKey->LoadPemFile("qa_data/signer_privkey.pem");
if ($success == 0) {
    print $privKey->lastErrorText() . "\r\n";
    exit;
}

#  Create a detached signature with separately supplied cert and private key, where the 3rd
#  argument controls whether the existing message header fields are transferred to the new outer
#  multipart/signed entity.
$transferHeaderFields = 1;
$success = $mime->AddDetachedSignaturePk2($cert,$privKey,$transferHeaderFields);
if ($success == 0) {
    print $mime->lastErrorText() . "\r\n";
    exit;
}

$success = $mime->SaveMime("qa_output/signed.eml");
if ($success == 0) {
    print $mime->lastErrorText() . "\r\n";
    exit;
}

print "Detached signature added (headers transferred)." . "\r\n";