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C#

Sign MIME using RSASSA-PSS with SHA256

See more MIME Examples

Demonstrates how to sign an MIME using the RSASSA-PSS signing algorithm with the SHA256 hash algorithm.

Chilkat C# Downloads

C#
bool success = false;

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

Chilkat.Mime mime = new Chilkat.Mime();

//  Create a MIME message to sign.
mime.NewMultipartMixed();
mime.AddHeaderField("someHeader1","Some value 1");
mime.AddHeaderField("someHeader2","Some value 2");

Chilkat.Mime part0 = new Chilkat.Mime();
part0.AddHeaderField("hdrA","Some value A");
part0.AddHeaderField("hdrB","Some value B");
part0.ContentType = "text/plain";
part0.SetBody("This is the plain-text body.");

Chilkat.Mime part1 = new Chilkat.Mime();
part1.AddHeaderField("hdrX","Some value X");
part1.AddHeaderField("hdrY","Some value Y");
part1.ContentType = "text/xml";
part1.SetBody("<a>This is the XML body</a>");

mime.AppendPart(part0);
mime.AppendPart(part1);

//  The MIME to be signed:
Chilkat.StringBuilder sbUnsignedMime = new Chilkat.StringBuilder();
mime.GetMimeSb(sbUnsignedMime);
Debug.WriteLine(sbUnsignedMime.GetAsString());

//  	Content-Type: multipart/mixed; boundary="------------080303020600020604010008"
//  	someHeader1: Some value 1
//  	someHeader2: Some value 2
//  
//  	--------------080303020600020604010008
//  	hdrA: Some value A
//  	hdrB: Some value B
//  	Content-Type: text/plain
//  
//  	This is the plain-text body.
//  	--------------080303020600020604010008
//  	hdrX: Some value X
//  	hdrY: Some value Y
//  	Content-Type: text/xml
//  
//  	<a>This is the XML body</a>
//  	--------------080303020600020604010008--
//  

//  Get a digital certificate with private key from a .pfx
//  (Chilkat has many different ways to provide a cert + private key for siging.
//  Using a PFX is just one possible option.)
Chilkat.Pfx pfx = new Chilkat.Pfx();
success = pfx.LoadPfxFile("qa_data/rsassa-pss/privatekey.pfx","PFX_PASSWORD");
if (success == false) {
    Debug.WriteLine(pfx.LastErrorText);
    return;
}

//  Get the certificate to be used for signing.
//  (The typical case for a PFX is that it contains a cert with an associated private key,
//  as well as other certificates in the chain of authentication.  The cert with the private
//  key should be in the first position at index 0.)

Chilkat.Cert cert = new Chilkat.Cert();
success = pfx.CertAt(0,cert);
if (success == false) {
    Debug.WriteLine(pfx.LastErrorText);
    return;
}

//  Indicate that RSASSA-PSS with SHA256 should be used.
mime.SigningAlg = "pss";
mime.SigningHashAlg = "sha256";

//  Add a detached signature.
success = mime.AddDetachedSignature(cert);
if (success != true) {
    Debug.WriteLine(mime.LastErrorText);
    return;
}

//  Show the clear-signed MIME. (see the sample output below)
Debug.WriteLine("-------------------------------------------------------------");
Debug.WriteLine("Clear-signed MIME using detached signature:");
Debug.WriteLine("-------------------------------------------------------------");
Debug.WriteLine(mime.GetMime());

//  Restore the original unsigned MIME, and this time create an opaque signature.
mime.LoadMime(sbUnsignedMime.GetAsString());

//  Sign using an opaque signature
success = mime.ConvertToSigned(cert);
if (success != true) {
    Debug.WriteLine(mime.LastErrorText);
    return;
}

//  Show the opaque-signed MIME. (see the sample output below)
Debug.WriteLine("-------------------------------------------------------------");
Debug.WriteLine("Opaque-signed MIME :");
Debug.WriteLine("-------------------------------------------------------------");
Debug.WriteLine(mime.GetMime());
Debug.WriteLine("Success.");

//  -----------------------------------------------
//  This is sample output for the clear-signed MIME:
//  -----------------------------------------------
//  
//  	Content-Type: multipart/signed; boundary="----=_NextPart_672_c95a_97b64c9a.90b5204d";
//  	 protocol="application/x-pkcs7-signature";
//  	 micalg=sha256
//  
//  	------=_NextPart_672_c95a_97b64c9a.90b5204d
//  	Content-Type: multipart/mixed; boundary="------------030207090102000301050504"
//  	someHeader1: Some value 1
//  	someHeader2: Some value 2
//  
//  	--------------030207090102000301050504
//  	hdrA: Some value A
//  	hdrB: Some value B
//  	Content-Type: text/plain
//  
//  	This is the plain-text body.
//  	--------------030207090102000301050504
//  	hdrX: Some value X
//  	hdrY: Some value Y
//  	Content-Type: text/xml
//  
//  	<a>This is the XML body</a>
//  	--------------030207090102000301050504--
//  
//  	------=_NextPart_672_c95a_97b64c9a.90b5204d
//  	Content-Transfer-Encoding: base64
//  	Content-Type: application/x-pkcs7-signature; name="smime.p7s"
//  	Content-Disposition: attachment; filename="smime.p7s"
//  
//  	MIIG5wYJKoZIhvcNAQcCoIIG2DCCBtQCAQExDzANBglghkgBZQMEAgEFADALBgkqhkiG9w0BBwGg
//  	ggL4MIIC9DCCAl2gAwIBAgIJAMPsJCT11cniMA0GCSqGSIb3DQEBCwUAMIGSMQswCQYDVQQGEwJB
//  	VTERMA8GA1UECAwIVmljdG9yaWExEjAQBgNVBAcMCU1lbGJvdXJuZTEhMB8GA1UECgwYSW50ZXJu
//  	ZXQgV2lkZ2l0cyBQdHkgTHRkMQ8wDQYDVQQDDAZXaWRnZXQxKDAmBgkqhkiG9w0BCQEWGWFkbWlu
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//  	MAkGA1UEBhMCQVUxETAPBgNVBAgMCFZpY3RvcmlhMRIwEAYDVQQHDAlNZWxib3VybmUxITAfBgNV
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//  	A1UEBhMCQVUxETAPBgNVBAgMCFZpY3RvcmlhMRIwEAYDVQQHDAlNZWxib3VybmUxITAfBgNVBAoM
//  	GEludGVybmV0IFdpZGdpdHMgUHR5IEx0ZDEPMA0GA1UEAwwGV2lkZ2V0MSgwJgYJKoZIhvcNAQkB
//  	FhlhZG1pbkBpbnRlcm5ldHdpZGdldHMuY29tAgkAw+wkJPXVyeIwPQYJKoZIhvcNAQEKMDCgDTAL
//  	BglghkgBZQMEAgGhGjAYBgkqhkiG9w0BAQgwCwYJYIZIAWUDBAIBogMCASAEgYAvqIqKBzNXyVbh
//  	TmaxdAc4d0ZTqWT6Na3C+DMO8owSKWy5FdGbJ2DLKm92qe/KLPTcj51vuwLUQb0Sw7r5Xknl+/6p
//  	Eqn2qe/6hgDn06vvzNofVAweOtSVJsBO7/cYYPc+pXZZ2BcpZDdf/9Ci56Yrlk7A72BeqPe47J3F
//  	neC8qw==
//  
//  	------=_NextPart_672_c95a_97b64c9a.90b5204d--
//  

//  -----------------------------------------------
//  This is sample output for the opaque-signed MIME:
//  -----------------------------------------------
//  	Content-Type: application/x-pkcs7-mime; name="smime.p7m"; smime-type="signed-data"
//  	someHeader1: Some value 1
//  	someHeader2: Some value 2
//  	Content-Disposition: attachment; filename="smime.p7m"
//  	Content-Transfer-Encoding: base64
//  
//  	MIIItAYJKoZIhvcNAQcCoIIIpTCCCKECAQExDzANBglghkgBZQMEAgEFADCCAdYGCSqGSIb3DQEH
//  	AaCCAccEggHDQ29udGVudC1UeXBlOiBtdWx0aXBhcnQvbWl4ZWQ7IGJvdW5kYXJ5PSItLS0tLS0t
//  	LS0tLS0wMDA2MDcwNzA3MDcwMTA1MDAwMTA5MDciDQpzb21lSGVhZGVyMTogU29tZSB2YWx1ZSAx
//  	DQpzb21lSGVhZGVyMjogU29tZSB2YWx1ZSAyDQoNCi0tLS0tLS0tLS0tLS0tMDAwNjA3MDcwNzA3
//  	MDEwNTAwMDEwOTA3DQpoZHJBOiBTb21lIHZhbHVlIEENCmhkckI6IFNvbWUgdmFsdWUgQg0KQ29u
//  	dGVudC1UeXBlOiB0ZXh0L3BsYWluDQoNClRoaXMgaXMgdGhlIHBsYWluLXRleHQgYm9keS4NCi0t
//  	LS0tLS0tLS0tLS0tMDAwNjA3MDcwNzA3MDEwNTAwMDEwOTA3DQpoZHJYOiBTb21lIHZhbHVlIFgN
//  	Cmhkclk6IFNvbWUgdmFsdWUgWQ0KQ29udGVudC1UeXBlOiB0ZXh0L3htbA0KDQo8YT5UaGlzIGlz
//  	IHRoZSBYTUwgYm9keTwvYT4NCi0tLS0tLS0tLS0tLS0tMDAwNjA3MDcwNzA3MDEwNTAwMDEwOTA3
//  	LS0NCqCCAvgwggL0MIICXaADAgECAgkAw+wkJPXVyeIwDQYJKoZIhvcNAQELBQAwgZIxCzAJBgNV
//  	BAYTAkFVMREwDwYDVQQIDAhWaWN0b3JpYTESMBAGA1UEBwwJTWVsYm91cm5lMSEwHwYDVQQKDBhJ
//  	bnRlcm5ldCBXaWRnaXRzIFB0eSBMdGQxDzANBgNVBAMMBldpZGdldDEoMCYGCSqGSIb3DQEJARYZ
//  	YWRtaW5AaW50ZXJuZXR3aWRnZXRzLmNvbTAeFw0xNjExMDExNjUyMzJaFw0yMTEwMzExNjUyMzJa
//  	MIGSMQswCQYDVQQGEwJBVTERMA8GA1UECAwIVmljdG9yaWExEjAQBgNVBAcMCU1lbGJvdXJuZTEh
//  	MB8GA1UECgwYSW50ZXJuZXQgV2lkZ2l0cyBQdHkgTHRkMQ8wDQYDVQQDDAZXaWRnZXQxKDAmBgkq
//  	hkiG9w0BCQEWGWFkbWluQGludGVybmV0d2lkZ2V0cy5jb20wgZ8wDQYJKoZIhvcNAQEBBQADgY0A
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//  	vBSTDsx74FOUulZBsEwfzuzoqmwLwxXJeEwuk/Sgzw0WLH+8vPbB0uFSHsJm8kDSmWqQmT1uPntA
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//  	+txDCzAfBgNVHSMEGDAWgBQ40oq7bOxciuKdbEgZPrni+txDCzAMBgNVHRMEBTADAQH/MA0GCSqG
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//  	/QTfrLOuzXKy
//