(Tcl) PKCS7 Encrypt using Multiple Certificates

Encrypts MIME using multiple digital certificates. Calls AddEncryptCert once per certificate, followed by a call to EncryptN. The MIME may be decrypted by any owner of one of the certificates + its associated private key.

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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.

set mime [new_CkMime]

# Build a simple MIME message to be encrypted:
set success [CkMime_AddHeaderField $mime "Content-Type" "text/plain"]
set success [CkMime_AddHeaderField $mime "abc" "123"]
CkMime_SetBody $mime "This is a test"

# A digital certificate is required to create PKCS7 encrypted MIME.
# It can come from a variety of sources: .cer file, .pfx file, PEM files,
# an in-memory representation, or directly from a Windows
# registry-based certificate store.

# Load one cert from a .cer file:
set cert1 [new_CkCert]

set success [CkCert_LoadFromFile $cert1 "myCert.cer"]
if {$success == 0} then {
    puts [CkCert_lastErrorText $cert1]
    delete_CkMime $mime
    delete_CkCert $cert1
    exit
}

# Load another cert ...
set cert2 [new_CkCert]

set success [CkCert_LoadFromFile $cert2 "anotherCert.cer"]
if {$success == 0} then {
    puts [CkCert_lastErrorText $cert2]
    delete_CkMime $mime
    delete_CkCert $cert1
    delete_CkCert $cert2
    exit
}

# Tell the MIME object to use these certs for encrypting:
# (AddEncryptCert shouldn't fail if we already know it contains
# a valid certificate..)
set success [CkMime_AddEncryptCert $mime $cert1]
set success [CkMime_AddEncryptCert $mime $cert2]

# Encrypt the MIME:
set success [CkMime_EncryptN $mime]
if {$success == 0} then {
    puts [CkMime_lastErrorText $mime]
    delete_CkMime $mime
    delete_CkCert $cert1
    delete_CkCert $cert2
    exit
}

# Display the MIME:
puts [CkMime_getMime $mime]

# The resulting S/MIME looks something like this:

# abc: 123
# Content-Disposition: attachment; filename="smime.p7m"
# Content-Transfer-Encoding: base64
# Content-Type: application/x-pkcs7-mime;
#  name="smime.p7m"
# 
# MIID4QYJKoZIhvcNAQcDoIID0jCCA84CAQAxggNlMIIBgQIBADBpMFUxCzAJBgNVBAYTAlpBMSUw
# IwYDVQQKExxUaGF3dGUgQ29uc3VsdGluZyAoUHR5KSBMdGQuMR8wHQYDVQQDExZUaGF3dGUgQ29k
# ZSBTaWduaW5nIENBAhB4ouTcAmLszrGi170k1deSMA0GCSqGSIb3DQEBAQUABIIBAKnOPgmISrNH
# Hd+zESvH5dl5TvBLCxLuIuH6cuZdowHzCqAUzaYFdn1rp88Vvu2x3s6WOvzje/+dE1x0YjEpeqxd
# ufehlb6Jl9ucxSMWARWMxWGxu0eZGJVt+SBBrVddqdtrIU9lVt5rBxkU67P8PxgbwdNCX3qJENRO
# P/rvp5ngoCkpIxeGqSkPvWv+CA3IXS8FPs8Sl4HNPiAj3e9RBm2MxI1u4cn1HvgGg8yHgHLMG5JF
# LzGsmotSQaqEwq2JtOlkjfOwEI+ZhbWQupj6gen2aGc5sW3J26H1usxtV2TQ7WRRxqnZGmlh20dW
# 4lo3kITYI+iapGlJXmrlDYh2CjkwggHcAgEAMIHDMIGuMQswCQYDVQQGEwJVUzELMAkGA1UECBMC
# VVQxFzAVBgNVBAcTDlNhbHQgTGFrZSBDaXR5MR4wHAYDVQQKExVUaGUgVVNFUlRSVVNUIE5ldHdv
# cmsxITAfBgNVBAsTGGh0dHA6Ly93d3cudXNlcnRydXN0LmNvbTE2MDQGA1UEAxMtVVROLVVTRVJG
# aXJzdC1DbGllbnQgQXV0aGVudGljYXRpb24gYW5kIEVtYWlsAhAj50QEWUPwA+jXOiL8sMwXMA0G
# CSqGSIb3DQEBAQUABIIBAFQ1cydWC4M9tdgAlCN03kP8eyuXajwT+5ByhOcJhjuCABg7U8w4Rx28
# braGqV+TCBxjyMsqD0KcW49VT6ZHMpQ1yN8R72qDsidmfm9w3u0jVgsaaBkTJXMy4COY/3cZWmYG
# dL3Qty8uFeQYddytt6UPJpGJZYsrdFG2doe6qHiRtAxxPrd0GmQRcGvxyDdsojkoBlTMbfwaXOI3
# xepR/oh60x/3npUCsl2VpNPfo6oZoej6YZGEuz2MvuWvXVhvuqoTqXGwGDgYMxwTbPwklqZiJtsK
# r5Ep3NlWAQX8MGWL0H+NC22cqJuqUCL05yqyAv+JMCpZGAwOVb/wiVNjpAIwYAYJKoZIhvcNAQcB
# MBkGCCqGSIb3DQMCMA0CAToECA5NAJY12cU+gDgZFUc+nsQUUbiR1GH8iBVLI+XWlja9TXEe1Hzt
# NlsOylRVBDzjNxUtX/zC0YR7bs+2Cf4JbyuMOA==

delete_CkMime $mime
delete_CkCert $cert1
delete_CkCert $cert2