(PureBasic) Encrypt MIME using RSAES-OAEP with SHA256 and AES-128 content encryption

Demonstrates how to encrypt MIME using RSAES-OAEP with SHA256 and AES-128 content encryption.

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

Chilkat PureBasic Module Download Chilkat PureBasic Module

IncludeFile "CkCert.pb"
IncludeFile "CkStringBuilder.pb"
IncludeFile "CkMime.pb"

Procedure ChilkatExample()

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

    success.i
    mime.i = CkMime::ckCreate()
    If mime.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    ; Create a MIME message to encrypt.
    CkMime::ckNewMultipartMixed(mime)
    CkMime::ckAddHeaderField(mime,"someHeader1","Some value 1")
    CkMime::ckAddHeaderField(mime,"someHeader2","Some value 2")

    part0.i = CkMime::ckCreate()
    If part0.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    CkMime::ckAddHeaderField(part0,"hdrA","Some value A")
    CkMime::ckAddHeaderField(part0,"hdrB","Some value B")
    CkMime::setCkContentType(part0, "text/plain")
    CkMime::ckSetBody(part0,"This is the plain-text body.")

    part1.i = CkMime::ckCreate()
    If part1.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    CkMime::ckAddHeaderField(part1,"hdrX","Some value X")
    CkMime::ckAddHeaderField(part1,"hdrY","Some value Y")
    CkMime::setCkContentType(part1, "text/xml")
    CkMime::ckSetBody(part1,"<a>This is the XML body</a>")

    CkMime::ckAppendPart(mime,part0)
    CkMime::ckAppendPart(mime,part1)

    ; The MIME to be encrypted:
    sbMime.i = CkStringBuilder::ckCreate()
    If sbMime.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    CkMime::ckGetMimeSb(mime,sbMime)
    Debug CkStringBuilder::ckGetAsString(sbMime)

    ; 	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--
    ; 

    ; Load an RSA-based certificate.
    ; (Encrypting MIME only requires the public key.  Decrypting MIME requires the private key.)
    cert.i = CkCert::ckCreate()
    If cert.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    success = CkCert::ckLoadFromFile(cert,"qa_data/rsaes-oaep/cert.pem")
    If success <> 1
        Debug CkCert::ckLastErrorText(cert)
        CkMime::ckDispose(mime)
        CkMime::ckDispose(part0)
        CkMime::ckDispose(part1)
        CkStringBuilder::ckDispose(sbMime)
        CkCert::ckDispose(cert)
        ProcedureReturn
    EndIf

    ; Set the email object properties to indicate the desired encryption.
    CkMime::setCkPkcs7CryptAlg(mime, "aes")
    ; If AES-256 is desired, set the following property to 256.
    CkMime::setCkPkcs7KeyLength(mime, 128)
    CkMime::setCkOaepPadding(mime, 1)
    ; Other choices for the OAEP hash algorithm are "sha1", "sha384", and "sha512"
    CkMime::setCkOaepHash(mime, "sha256")

    ; Encrypt the MIME (to create S/MIME, which stands for "Secure MIME")
    success = CkMime::ckEncrypt(mime,cert)
    If success <> 1
        Debug CkMime::ckLastErrorText(mime)
        CkMime::ckDispose(mime)
        CkMime::ckDispose(part0)
        CkMime::ckDispose(part1)
        CkStringBuilder::ckDispose(sbMime)
        CkCert::ckDispose(cert)
        ProcedureReturn
    EndIf

    Debug "---------------"
    Debug "Encrypted MIME:"
    Debug "---------------"
    Debug CkMime::ckGetMime(mime)

    Debug "Success."

    ; ---------------------------------------------------
    ; This is sample output for RSAES-OAEP encrypted MIME:
    ; ---------------------------------------------------

    ; Content-Type: application/x-pkcs7-mime; name="smime.p7m"; smime-type="enveloped-data"
    ; someHeader1: Some value 1
    ; someHeader2: Some value 2
    ; Content-Disposition: attachment; filename="smime.p7m"
    ; Content-Transfer-Encoding: base64
    ; 
    ; MIIDvAYJKoZIhvcNAQcDoIIDrTCCA6kCAQAxggGgMIIBnAIBADB1MGgxCzAJBgNVBAYTAlVTMQsw
    ; CQYDVQQIDAJJTDEQMA4GA1UEBwwHV2hlYXRvbjEhMB8GA1UECgwYSW50ZXJuZXQgV2lkZ2l0cyBQ
    ; dHkgTHRkMRcwFQYDVQQDDA5DaGlsa2F0V2lkZ2V0cwIJAMRwugDmvniwMBwGCSqGSIb3DQEBBzAP
    ; oA0wCwYJYIZIAWUDBAIBBIIBAFaUL1ga1bOrdqYKcMm+FHUacBvzfBxk0fnPA0AMBdN8BvTWT3CN
    ; YuqBhjOGyq0FpYD9pVZybUuFMCVsVyIW2O62HnsOK58YaPEUUcdH2sI+yjqX9UAn0P0nVDSsVdeK
    ; W8x9kMfZg+3UP+y1q+lu7VRJO3f2C9oLQpTkc4VW4n7UOcUI0waykLCjCTL8lFDb7/J3GeuMKyhH
    ; 5riNz50kpbzqn7m2Ks9yA+QmcTdXclclGFr2vwEUFzSdT2pxh/vaUrogCxkYWbQ2eV7vZg6O4kV0
    ; aqHBqySkPTAzHKiHH8K8GVdlTuJ8350CpICa4T8w7/Ht5I7dyOPPKy4C+rVtrvcwggH+BgkqhkiG
    ; 9w0BBwEwHQYJYIZIAWUDBAECBBDTC2WNBN+z2I47/4Feu9YqgIIB0MZvl3nC/q/Wzil6HtfQTr12
    ; Q5moHY+ORzAa1P9XvX2ZUFhW530mV395mQw/A4o4ekmX9eRPEZquYzZPLT8hNeZIuNdhpcSQUmad
    ; rKnKkR0wKJ3jJ3LhOIohVBQSYs8kVDZKq6lJBIznlsurFelZoNEhyRschhteDZx5rb7fCe8c2+/O
    ; DHxaqaHCAzm/Bd7kcg6FFfuTZy3tu0PgP5IsXN4OFA3kkvwjAs4XsVS8jdIcmDNBkYieE8WmJOIm
    ; Mz7mh/CHWLgWfGKa0Dkb9RcbFgLwYNT3GzuXFw9XPbKkEZjEAtJajWbN6P0WQl96YYd9qZxUpGxZ
    ; zjTHEYzViUdUXolfpLufttrRXyxN1RFWhNFMFbv66xYqklMSgpdM/Mbk+EuvX6eXayDPvDBpfYMw
    ; NoRAzv1Ony2c0ez9rBemJICicxAzpuvHbRxdjYs63Dnv+TYgpBK12AxWWpPIjXvw0WQKgTC3Tg8s
    ; EnuGhpENqso/clJBEBSn4+2WhYtYbdI5sVme67lvqQl1Xxy3r18SWaQbyDOwgYi1E+54lMDOxMy0
    ; y0FPHk5pP45DnXWj+XORPp5LhuZr5mf62YOXSSUwR5P0cXy4Rc+pN5lhRQPCf5z2


    CkMime::ckDispose(mime)
    CkMime::ckDispose(part0)
    CkMime::ckDispose(part1)
    CkStringBuilder::ckDispose(sbMime)
    CkCert::ckDispose(cert)


    ProcedureReturn
EndProcedure