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Unicode C

Send a Signed Email using RSASSA-PSS with SHA256

See more SMTP Examples

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

Chilkat Unicode C Downloads

Unicode C
#include <C_CkPfxW.h>
#include <C_CkEmailW.h>
#include <C_CkCertW.h>
#include <C_CkMailManW.h>

void ChilkatSample(void)
    {
    BOOL success;
    HCkPfxW pfx;
    HCkEmailW email;
    HCkCertW cert;
    HCkMailManW mailman;

    success = FALSE;

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

    //  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.)
    pfx = CkPfxW_Create();
    success = CkPfxW_LoadPfxFile(pfx,L"qa_data/rsassa-pss/privatekey.pfx",L"PFX_PASSWORD");
    if (success == FALSE) {
        wprintf(L"%s\n",CkPfxW_lastErrorText(pfx));
        CkPfxW_Dispose(pfx);
        return;
    }

    email = CkEmailW_Create();

    //  Create a simple email.
    CkEmailW_putSubject(email,L"Sample RSASSA-PSS Signed Email");
    CkEmailW_putBody(email,L"Sample RSASSA-PSS Signed Email");
    CkEmailW_putFrom(email,L"from_name@mydomain.com");
    //  Add one ore more recipients..
    CkEmailW_AddTo(email,L"Chilkat Support",L"support@chilkatsoft.com");
    CkEmailW_AddTo(email,L"Chilkat GMail",L"chilkat.support@gmail.com");

    //  Indicate that the email is to be signed, and that we want to use RSASSA-PSS.
    CkEmailW_putSendSigned(email,TRUE);
    CkEmailW_putSigningAlg(email,L"pss");
    CkEmailW_putSigningHashAlg(email,L"sha256");

    //  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.)

    cert = CkCertW_Create();
    success = CkPfxW_CertAt(pfx,0,cert);
    if (success == FALSE) {
        wprintf(L"%s\n",CkPfxW_lastErrorText(pfx));
        CkPfxW_Dispose(pfx);
        CkEmailW_Dispose(email);
        CkCertW_Dispose(cert);
        return;
    }

    //  Tell the email object to use this cert (and private key) for signing.
    CkEmailW_SetSigningCert(email,cert);

    mailman = CkMailManW_Create();

    //  Set the SMTP settings for your email account on your mail server.
    CkMailManW_putSmtpUsername(mailman,L"SMTP_LOGIN");
    CkMailManW_putSmtpPassword(mailman,L"SMTP_PASSWORD");
    CkMailManW_putSmtpHost(mailman,L"MY_SMTP_DOMAIN_OR_IP");
    CkMailManW_putSmtpPort(mailman,587);
    CkMailManW_putStartTLS(mailman,TRUE);

    //  Signed email can be sent in two different ways.  
    //  In a multipart/signed email, the signature is attached as a separate MIME part.
    //  In an opaque email (signedData) the content of the email is encapsulated within the signature
    //  and the email is sent as "application/pkcs7-mime". 
    //  Either should be fine, but some receiving systems might require one or the other..
    CkMailManW_putOpaqueSigning(mailman,FALSE);

    //  Send the email.  The mailman will sign the email as directed by the 
    //  property settings of the email object.
    success = CkMailManW_SendEmail(mailman,email);
    if (success == FALSE) {
        wprintf(L"%s\n",CkMailManW_lastErrorText(mailman));
        CkPfxW_Dispose(pfx);
        CkEmailW_Dispose(email);
        CkCertW_Dispose(cert);
        CkMailManW_Dispose(mailman);
        return;
    }

    success = CkMailManW_CloseSmtpConnection(mailman);
    if (success != TRUE) {
        wprintf(L"Connection to SMTP server not closed cleanly.\n");
    }

    wprintf(L"Mail Sent!\n");

    //  -----------------------------------------------------------
    //  This is the MIME of the RSASSA-PSS signed email that was sent

    //  	MIME-Version: 1.0
    //  	Date: Thu, 20 Apr 2017 10:14:58 -0500
    //  	Message-ID: <3682A87344CB3A4FB5EB5BC9908C0C4DA01DA461@CHILKAT13>
    //  	Content-Type: multipart/signed; protocol="application/pkcs7-signature"; micalg=sha256;
    //  	 boundary="------------050103020705000601010800"
    //  	X-Priority: 3 (Normal)
    //  	Subject: Sample RSASSA-PSS Signed Email
    //  	From: support@chilkatsoft.com
    //  	To: "Chilkat Support" <support@chilkatsoft.com>,
    //  	 "Chilkat GMail" <chilkat.support@gmail.com>
    //  
    //  	--------------050103020705000601010800
    //  	Content-Type: text/plain; format=flowed
    //  	Content-Transfer-Encoding: 7bit
    //  
    //  	Sample RSASSA-PSS Signed Email
    //  	--------------050103020705000601010800
    //  	Content-Transfer-Encoding: base64
    //  	Content-Type: application/pkcs7-signature; name="smime.p7s"
    //  	Content-Disposition: attachment; filename="smime.p7s"
    //  
    //  	MIIG5wYJKoZIhvcNAQcCoIIG2DCCBtQCAQExDzANBglghkgBZQMEAgEFADALBgkqhkiG9w0BBwGg
    //  	ggL4MIIC9DCCAl2gAwIBAgIJAMPsJCT11cniMA0GCSqGSIb3DQEBCwUAMIGSMQswCQYDVQQGEwJB
    //  	VTERMA8GA1UECAwIVmljdG9yaWExEjAQBgNVBAcMCU1lbGJvdXJuZTEhMB8GA1UECgwYSW50ZXJu
    //  	ZXQgV2lkZ2l0cyBQdHkgTHRkMQ8wDQYDVQQDDAZXaWRnZXQxKDAmBgkqhkiG9w0BCQEWGWFkbWlu
    //  	QGludGVybmV0d2lkZ2V0cy5jb20wHhcNMTYxMTAxMTY1MjMyWhcNMjExMDMxMTY1MjMyWjCBkjEL
    //  	MAkGA1UEBhMCQVUxETAPBgNVBAgMCFZpY3RvcmlhMRIwEAYDVQQHDAlNZWxib3VybmUxITAfBgNV
    //  	BAoMGEludGVybmV0IFdpZGdpdHMgUHR5IEx0ZDEPMA0GA1UEAwwGV2lkZ2V0MSgwJgYJKoZIhvcN
    //  	AQkBFhlhZG1pbkBpbnRlcm5ldHdpZGdldHMuY29tMIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKB
    //  	gQDGIdoCjyavs+F/Rm0VIB4m6O7VL1j+1IqieoR9NEX2GQvu2VCdceyxf9qaw1bxipEvjLwUkw7M
    //  	e+BTlLpWQbBMH87s6KpsC8MVyXhMLpP0oM8NFix/vLz2wdLhUh7CZvJA0plqkJk9bj57QIu+EO1k
    //  	tUHM2DFb6sckvCL2yybD1wIDAQABo1AwTjAdBgNVHQ4EFgQUONKKu2zsXIrinWxIGT654vrcQwsw
    //  	HwYDVR0jBBgwFoAUONKKu2zsXIrinWxIGT654vrcQwswDAYDVR0TBAUwAwEB/zANBgkqhkiG9w0B
    //  	AQsFAAOBgQArFvdi5u9i2QF1Qw+cdC1l7w2Y3+q6RIkln2W8rWJFje00644o8hXy7v46giJCedmF
    //  	ULlhm1n7XIsZGy2W3lJ77v5agn9gFwXu1h3cqkGXkoteE6SQJQXWgsW3GWPveObvTL8LF4y57fgM
    //  	9ZWS+V9MJajeu44Rf/tU17TLYKjvEjGCA7MwggOvAgEBMIGgMIGSMQswCQYDVQQGEwJBVTERMA8G
    //  	A1UECAwIVmljdG9yaWExEjAQBgNVBAcMCU1lbGJvdXJuZTEhMB8GA1UECgwYSW50ZXJuZXQgV2lk
    //  	Z2l0cyBQdHkgTHRkMQ8wDQYDVQQDDAZXaWRnZXQxKDAmBgkqhkiG9w0BCQEWGWFkbWluQGludGVy
    //  	bmV0d2lkZ2V0cy5jb20CCQDD7CQk9dXJ4jANBglghkgBZQMEAgEFAKCCAjQwGAYJKoZIhvcNAQkD
    //  	MQsGCSqGSIb3DQEHATAcBgkqhkiG9w0BCQUxDxcNMTcwNDIwMTUxNDU4WjAvBgkqhkiG9w0BCQQx
    //  	IgQgoHOtpFiAgti0cwDw46C8wyYSZbhx2yJqJZ/qRE8WPSQwXwYJKoZIhvcNAQkPMVIwUDALBglg
    //  	hkgBZQMEAQIwCgYIKoZIhvcNAwcwDgYIKoZIhvcNAwICAgCAMA0GCCqGSIb3DQMCAgFAMAcGBSsO
    //  	AwIHMA0GCCqGSIb3DQMCAgEoMIGxBgkrBgEEAYI3EAQxgaMwgaAwgZIxCzAJBgNVBAYTAkFVMREw
    //  	DwYDVQQIDAhWaWN0b3JpYTESMBAGA1UEBwwJTWVsYm91cm5lMSEwHwYDVQQKDBhJbnRlcm5ldCBX
    //  	aWRnaXRzIFB0eSBMdGQxDzANBgNVBAMMBldpZGdldDEoMCYGCSqGSIb3DQEJARYZYWRtaW5AaW50
    //  	ZXJuZXR3aWRnZXRzLmNvbQIJAMPsJCT11cniMIGzBgsqhkiG9w0BCRACCzGBo6CBoDCBkjELMAkG
    //  	A1UEBhMCQVUxETAPBgNVBAgMCFZpY3RvcmlhMRIwEAYDVQQHDAlNZWxib3VybmUxITAfBgNVBAoM
    //  	GEludGVybmV0IFdpZGdpdHMgUHR5IEx0ZDEPMA0GA1UEAwwGV2lkZ2V0MSgwJgYJKoZIhvcNAQkB
    //  	FhlhZG1pbkBpbnRlcm5ldHdpZGdldHMuY29tAgkAw+wkJPXVyeIwPQYJKoZIhvcNAQEKMDCgDTAL
    //  	BglghkgBZQMEAgGhGjAYBgkqhkiG9w0BAQgwCwYJYIZIAWUDBAIBogMCASAEgYCDQpT6vJZ9zERJ
    //  	JVX69PGUfCN5Eq9pKzoOTQSrIBe1YgNDSPd5pyOPP2MN1RpI0T/GTQZw4iWy5LZq0T5sjmk3fFVB
    //  	+VZjKtkTuhGaCdzMQXomVLBbI2fN4UaA4v1/Ayrqr8SY9Rsa20TpKv/bufK7oYs083UOtlcA1EHY
    //  	41wQ5A==
    //  
    //  	--------------050103020705000601010800--


    CkPfxW_Dispose(pfx);
    CkEmailW_Dispose(email);
    CkCertW_Dispose(cert);
    CkMailManW_Dispose(mailman);

    }