(Tcl) Send a Signed Email using RSASSA-PSS with SHA256

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

Note: This example requires Chilkat v9.5.0.67 or greater.

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load ./chilkat.dll

# 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.)
set pfx [new_CkPfx]

set success [CkPfx_LoadPfxFile $pfx "qa_data/rsassa-pss/privatekey.pfx" "PFX_PASSWORD"]
if {$success != 1} then {
    puts [CkPfx_lastErrorText $pfx]
    delete_CkPfx $pfx
    exit
}

set email [new_CkEmail]

# Create a simple email.
CkEmail_put_Subject $email "Sample RSASSA-PSS Signed Email"
CkEmail_put_Body $email "Sample RSASSA-PSS Signed Email"
CkEmail_put_From $email "from_name@mydomain.com"
# Add one ore more recipients..
CkEmail_AddTo $email "Chilkat Support" "support@chilkatsoft.com"
CkEmail_AddTo $email "Chilkat GMail" "chilkat.support@gmail.com"

# Indicate that the email is to be signed, and that we want to use RSASSA-PSS.
CkEmail_put_SendSigned $email 1
CkEmail_put_SigningAlg $email "pss"
CkEmail_put_SigningHashAlg $email "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 is a CkCert
set cert [CkPfx_GetCert $pfx 0]
if {[CkPfx_get_LastMethodSuccess $pfx] != 1} then {
    puts [CkPfx_lastErrorText $pfx]
    delete_CkPfx $pfx
    delete_CkEmail $email
    exit
}

# Tell the email object to use this cert (and private key) for signing.
CkEmail_SetSigningCert $email $cert
delete_CkCert $cert

set mailman [new_CkMailMan]

# Set the SMTP settings for your email account on your mail server.
CkMailMan_put_SmtpUsername $mailman "SMTP_LOGIN"
CkMailMan_put_SmtpPassword $mailman "SMTP_PASSWORD"
CkMailMan_put_SmtpHost $mailman "MY_SMTP_DOMAIN_OR_IP"
CkMailMan_put_SmtpPort $mailman 587
CkMailMan_put_StartTLS $mailman 1

# 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..
CkMailMan_put_OpaqueSigning $mailman 0

# Send the email.  The mailman will sign the email as directed by the 
# property settings of the email object.
set success [CkMailMan_SendEmail $mailman $email]
if {$success != 1} then {
    puts [CkMailMan_lastErrorText $mailman]
    delete_CkPfx $pfx
    delete_CkEmail $email
    delete_CkMailMan $mailman
    exit
}

set success [CkMailMan_CloseSmtpConnection $mailman]
if {$success != 1} then {
    puts "Connection to SMTP server not closed cleanly."
}

puts "Mail Sent!"

# -----------------------------------------------------------
# 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
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# 	A1UECAwIVmljdG9yaWExEjAQBgNVBAcMCU1lbGJvdXJuZTEhMB8GA1UECgwYSW50ZXJuZXQgV2lk
# 	Z2l0cyBQdHkgTHRkMQ8wDQYDVQQDDAZXaWRnZXQxKDAmBgkqhkiG9w0BCQEWGWFkbWluQGludGVy
# 	bmV0d2lkZ2V0cy5jb20CCQDD7CQk9dXJ4jANBglghkgBZQMEAgEFAKCCAjQwGAYJKoZIhvcNAQkD
# 	MQsGCSqGSIb3DQEHATAcBgkqhkiG9w0BCQUxDxcNMTcwNDIwMTUxNDU4WjAvBgkqhkiG9w0BCQQx
# 	IgQgoHOtpFiAgti0cwDw46C8wyYSZbhx2yJqJZ/qRE8WPSQwXwYJKoZIhvcNAQkPMVIwUDALBglg
# 	hkgBZQMEAQIwCgYIKoZIhvcNAwcwDgYIKoZIhvcNAwICAgCAMA0GCCqGSIb3DQMCAgFAMAcGBSsO
# 	AwIHMA0GCCqGSIb3DQMCAgEoMIGxBgkrBgEEAYI3EAQxgaMwgaAwgZIxCzAJBgNVBAYTAkFVMREw
# 	DwYDVQQIDAhWaWN0b3JpYTESMBAGA1UEBwwJTWVsYm91cm5lMSEwHwYDVQQKDBhJbnRlcm5ldCBX
# 	aWRnaXRzIFB0eSBMdGQxDzANBgNVBAMMBldpZGdldDEoMCYGCSqGSIb3DQEJARYZYWRtaW5AaW50
# 	ZXJuZXR3aWRnZXRzLmNvbQIJAMPsJCT11cniMIGzBgsqhkiG9w0BCRACCzGBo6CBoDCBkjELMAkG
# 	A1UEBhMCQVUxETAPBgNVBAgMCFZpY3RvcmlhMRIwEAYDVQQHDAlNZWxib3VybmUxITAfBgNVBAoM
# 	GEludGVybmV0IFdpZGdpdHMgUHR5IEx0ZDEPMA0GA1UEAwwGV2lkZ2V0MSgwJgYJKoZIhvcNAQkB
# 	FhlhZG1pbkBpbnRlcm5ldHdpZGdldHMuY29tAgkAw+wkJPXVyeIwPQYJKoZIhvcNAQEKMDCgDTAL
# 	BglghkgBZQMEAgGhGjAYBgkqhkiG9w0BAQgwCwYJYIZIAWUDBAIBogMCASAEgYCDQpT6vJZ9zERJ
# 	JVX69PGUfCN5Eq9pKzoOTQSrIBe1YgNDSPd5pyOPP2MN1RpI0T/GTQZw4iWy5LZq0T5sjmk3fFVB
# 	+VZjKtkTuhGaCdzMQXomVLBbI2fN4UaA4v1/Ayrqr8SY9Rsa20TpKv/bufK7oYs083UOtlcA1EHY
# 	41wQ5A==
# 
# 	--------------050103020705000601010800--

delete_CkPfx $pfx
delete_CkEmail $email
delete_CkMailMan $mailman