(PureBasic) Encrypt/Decrypt using PFX to produce -----BEGIN PKCS7----- ... -----END PKCS7-----

First we encrypt using a certificate + public key to produce output such as:

-----BEGIN PKCS7-----
MIIHPwYJKoZIhvcNAQcEoIIHMDCCBywC ...
...
...
-----END PKCS7-----

Chilkat PureBasic Module Download Chilkat PureBasic Module

IncludeFile "CkCert.pb"
IncludeFile "CkStringBuilder.pb"
IncludeFile "CkCrypt2.pb"

Procedure ChilkatExample()

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

    crypt.i = CkCrypt2::ckCreate()
    If crypt.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    ; Specify the encryption to be used.
    ; "pki" indicates "Public Key Infrastructure" and will create a PKCS7 encrypted (enveloped) message.
    CkCrypt2::setCkCryptAlgorithm(crypt, "pki")
    CkCrypt2::setCkPkcs7CryptAlg(crypt, "aes")
    CkCrypt2::setCkKeyLength(crypt, 128)
    CkCrypt2::setCkOaepHash(crypt, "sha256")
    CkCrypt2::setCkOaepPadding(crypt, 1)

    ; A certificate is needed as the encryption key.
    ; Althought the PFX contains the associated private key, we don't need it for encryption.
    ; (A certificate usually contains the public key by default.)
    cert.i = CkCert::ckCreate()
    If cert.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    success.i = CkCert::ckLoadPfxFile(cert,"qa_data/pfx/cert_test123.pfx","test123")
    If success <> 1
        Debug CkCert::ckLastErrorText(cert)
        CkCrypt2::ckDispose(crypt)
        CkCert::ckDispose(cert)
        ProcedureReturn
    EndIf

    ; Tell the crypt object to use the certificate.
    CkCrypt2::ckSetEncryptCert(crypt,cert)

    toBeEncrypted.s = "This string is to be encrypted."

    ; Get the result in multi-line BASE64 MIME format.
    CkCrypt2::setCkEncodingMode(crypt, "base64_mime")

    encryptedStr.s = CkCrypt2::ckEncryptStringENC(crypt,toBeEncrypted)
    If success <> 1
        Debug CkCrypt2::ckLastErrorText(crypt)
        CkCrypt2::ckDispose(crypt)
        CkCert::ckDispose(cert)
        ProcedureReturn
    EndIf

    ; Make a "-----BEGIN PKCS7-----" ... "-----END PKCS7-----" sandwich...
    sb.i = CkStringBuilder::ckCreate()
    If sb.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    CkStringBuilder::ckAppendLine(sb,"-----BEGIN PKCS7-----",1)
    CkStringBuilder::ckAppend(sb,encryptedStr)
    CkStringBuilder::ckAppendLine(sb,"-----END PKCS7-----",1)

    outStr.s = CkStringBuilder::ckGetAsString(sb)

    Debug outStr

    ; Sample output:

    ; -----BEGIN PKCS7-----
    ; MIICXAYJKoZIhvcNAQcDoIICTTCCAkkCAQAxggH0MIIB8AIBADCBrDCBlzELMAkGA1UEBhMCR0Ix
    ; GzAZBgNVBAgTEkdyZWF0ZXIgTWFuY2hlc3RlcjEQMA4GA1UEBxMHU2FsZm9yZDEaMBgGA1UEChMR
    ; Q09NT0RPIENBIExpbWl0ZWQxPTA7BgNVBAMTNENPTU9ETyBSU0EgQ2xpZW50IEF1dGhlbnRpY2F0
    ; aW9uIGFuZCBTZWN1cmUgRW1haWwgQ0ECEB6M1ZwZdZU7LrAIdurulmUwOAYJKoZIhvcNAQEHMCug
    ; DzANBglghkgBZQMEAgEFAKEYMBYGCSqGSIb3DQEBCDAJBgUrDgMCGgUABIIBAK/BZG/iXJ8az7zL
    ; 8EQ77mc+oDPQ4w1hyytK2ip4djkPVvTfYhcoDQ+G/DBU+urJfrVBi5H9gmpXwYyfKlyUxBVRVEJl
    ; V/V5QQi4JmNTFbmgWh5tp9zDS98l6A2Va4Zs0Wy/owGLfvwitlxd1dsfVAV2hmBYS24BMpNcty5/
    ; 0atcKYmSou13G78ztTKdMy1tECgZy8kerMsPdDQbSxEZkT3KpQ8C5uEQqYF3bIVaeZzha/Ywieh/
    ; tvO0T4aAmeJufwkNdVECmU7kuhnNaVPXknFl7jeibTl6zA/VcJKBKcIYT9FRC7KjdooI8q+jtQ/V
    ; k6RP4POaowkFg1QWRPEWeqIwTAYJKoZIhvcNAQcBMB0GCWCGSAFlAwQBAgQQEEFQduqeJqXQXzy4
    ; JpkoDoAgdldJDB9zEkpMpgr5/fR2iLvh5kC6BPfhOYjsawBY4Ok=
    ; -----END PKCS7-----

    ; ----------------------------------------------------------------------------------------
    ; Let's Decrypt the above string.

    ; Start with what was produced above..
    CkStringBuilder::ckClear(sb)
    bCrlf.i = 1
    CkStringBuilder::ckAppendLine(sb,"-----BEGIN PKCS7-----",bCrlf)
    CkStringBuilder::ckAppendLine(sb,"MIICXAYJKoZIhvcNAQcDoIICTTCCAkkCAQAxggH0MIIB8AIBADCBrDCBlzELMAkGA1UEBhMCR0Ix",bCrlf)
    CkStringBuilder::ckAppendLine(sb,"GzAZBgNVBAgTEkdyZWF0ZXIgTWFuY2hlc3RlcjEQMA4GA1UEBxMHU2FsZm9yZDEaMBgGA1UEChMR",bCrlf)
    CkStringBuilder::ckAppendLine(sb,"Q09NT0RPIENBIExpbWl0ZWQxPTA7BgNVBAMTNENPTU9ETyBSU0EgQ2xpZW50IEF1dGhlbnRpY2F0",bCrlf)
    CkStringBuilder::ckAppendLine(sb,"aW9uIGFuZCBTZWN1cmUgRW1haWwgQ0ECEB6M1ZwZdZU7LrAIdurulmUwOAYJKoZIhvcNAQEHMCug",bCrlf)
    CkStringBuilder::ckAppendLine(sb,"DzANBglghkgBZQMEAgEFAKEYMBYGCSqGSIb3DQEBCDAJBgUrDgMCGgUABIIBAK/BZG/iXJ8az7zL",bCrlf)
    CkStringBuilder::ckAppendLine(sb,"8EQ77mc+oDPQ4w1hyytK2ip4djkPVvTfYhcoDQ+G/DBU+urJfrVBi5H9gmpXwYyfKlyUxBVRVEJl",bCrlf)
    CkStringBuilder::ckAppendLine(sb,"V/V5QQi4JmNTFbmgWh5tp9zDS98l6A2Va4Zs0Wy/owGLfvwitlxd1dsfVAV2hmBYS24BMpNcty5/",bCrlf)
    CkStringBuilder::ckAppendLine(sb,"0atcKYmSou13G78ztTKdMy1tECgZy8kerMsPdDQbSxEZkT3KpQ8C5uEQqYF3bIVaeZzha/Ywieh/",bCrlf)
    CkStringBuilder::ckAppendLine(sb,"tvO0T4aAmeJufwkNdVECmU7kuhnNaVPXknFl7jeibTl6zA/VcJKBKcIYT9FRC7KjdooI8q+jtQ/V",bCrlf)
    CkStringBuilder::ckAppendLine(sb,"k6RP4POaowkFg1QWRPEWeqIwTAYJKoZIhvcNAQcBMB0GCWCGSAFlAwQBAgQQEEFQduqeJqXQXzy4",bCrlf)
    CkStringBuilder::ckAppendLine(sb,"JpkoDoAgdldJDB9zEkpMpgr5/fR2iLvh5kC6BPfhOYjsawBY4Ok=",bCrlf)
    CkStringBuilder::ckAppendLine(sb,"-----END PKCS7-----",bCrlf)

    decrypt.i = CkCrypt2::ckCreate()
    If decrypt.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    CkCrypt2::setCkCryptAlgorithm(decrypt, "pki")

    ; Use the same cert + private key from the PFX above.
    ; For decryption, we need the private key.  Given that the certificate was loaded from a PFX,
    ; we should already have it.
    success = CkCrypt2::ckSetDecryptCert(decrypt,cert)

    CkCrypt2::setCkEncodingMode(decrypt, "base64")
    decryptedText.s = CkCrypt2::ckDecryptStringENC(decrypt,CkStringBuilder::ckGetBetween(sb,"-----BEGIN PKCS7-----","-----END PKCS7-----"))

    Debug decryptedText


    CkCrypt2::ckDispose(crypt)
    CkCert::ckDispose(cert)
    CkStringBuilder::ckDispose(sb)
    CkCrypt2::ckDispose(decrypt)


    ProcedureReturn
EndProcedure