MIME S/MIME Signing Algorithm Properties

See more MIME Examples

Demonstrates the properties that control S/MIME signing: SigningAlg (the RSA signature scheme, PKCS1-V1_5 or RSASSA-PSS), SigningHashAlg (the message-digest algorithm), Micalg and Protocol (the micalg and protocol parameters of a multipart/signed Content-Type), and UseXPkcs7 (whether historical x-pkcs7 media-type names are used). The properties are configured before creating a detached signature.

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;
}

#  SigningAlg is the RSA signature scheme.  The default is PKCS1-V1_5; set RSASSA-PSS (or pss) for
#  RSASSA-PSS.
$mime->put_SigningAlg("PKCS1-V1_5");

#  SigningHashAlg is the message-digest algorithm.  The default is sha256.
$mime->put_SigningHashAlg("sha256");

#  Micalg and Protocol are the micalg and protocol parameters written into a multipart/signed
#  Content-Type header field.  They are normally set automatically, but can be controlled here.
$mime->put_Micalg("sha-256");
$mime->put_Protocol("application/pkcs7-signature");

#  UseXPkcs7 controls whether newly created S/MIME media types use the historical x-pkcs7 names.
$mime->put_UseXPkcs7(0);

#  Load a signing certificate (with private key access) from a PFX.  The PFX password should come
#  from a secure source rather than being hard-coded.
$pfxPassword = "myPfxPassword";
$cert = chilkat::CkCert->new();
$success = $cert->LoadPfxFile("qa_data/signer.pfx",$pfxPassword);
if ($success == 0) {
    print $cert->lastErrorText() . "\r\n";
    exit;
}

#  Create the detached signature using the algorithms configured above.
$success = $mime->AddDetachedSignature($cert);
if ($success == 0) {
    print $mime->lastErrorText() . "\r\n";
    exit;
}

print "Signed with SigningAlg=" . $mime->signingAlg() . " SigningHashAlg=" . $mime->signingHashAlg() . "\r\n";