(AutoIt) 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 ActiveX Downloads ActiveX for 32-bit and 64-bit Windows

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

$oCrypt = ObjCreate("Chilkat.Crypt2")

; Specify the encryption to be used.
; "pki" indicates "Public Key Infrastructure" and will create a PKCS7 encrypted (enveloped) message.
$oCrypt.CryptAlgorithm = "pki"
$oCrypt.Pkcs7CryptAlg = "aes"
$oCrypt.KeyLength = 128
$oCrypt.OaepHash = "sha256"
$oCrypt.OaepPadding = True

; 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.)
$oCert = ObjCreate("Chilkat.Cert")
Local $bSuccess = $oCert.LoadPfxFile("qa_data/pfx/cert_test123.pfx","test123")
If ($bSuccess <> True) Then
    ConsoleWrite($oCert.LastErrorText & @CRLF)
    Exit
EndIf

; Tell the crypt object to use the certificate.
$oCrypt.SetEncryptCert($oCert)

Local $sToBeEncrypted = "This string is to be encrypted."

; Get the result in multi-line BASE64 MIME format.
$oCrypt.EncodingMode = "base64_mime"

Local $sEncryptedStr = $oCrypt.EncryptStringENC($sToBeEncrypted)
If ($bSuccess <> True) Then
    ConsoleWrite($oCrypt.LastErrorText & @CRLF)
    Exit
EndIf

; Make a "-----BEGIN PKCS7-----" ... "-----END PKCS7-----" sandwich...
$oSb = ObjCreate("Chilkat.StringBuilder")
$oSb.AppendLine("-----BEGIN PKCS7-----",True)
$oSb.Append($sEncryptedStr)
$oSb.AppendLine("-----END PKCS7-----",True)

Local $sOutStr = $oSb.GetAsString()

ConsoleWrite($sOutStr & @CRLF)

; 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..
$oSb.Clear 
Local $bCrlf = True
$oSb.AppendLine("-----BEGIN PKCS7-----",$bCrlf)
$oSb.AppendLine("MIICXAYJKoZIhvcNAQcDoIICTTCCAkkCAQAxggH0MIIB8AIBADCBrDCBlzELMAkGA1UEBhMCR0Ix",$bCrlf)
$oSb.AppendLine("GzAZBgNVBAgTEkdyZWF0ZXIgTWFuY2hlc3RlcjEQMA4GA1UEBxMHU2FsZm9yZDEaMBgGA1UEChMR",$bCrlf)
$oSb.AppendLine("Q09NT0RPIENBIExpbWl0ZWQxPTA7BgNVBAMTNENPTU9ETyBSU0EgQ2xpZW50IEF1dGhlbnRpY2F0",$bCrlf)
$oSb.AppendLine("aW9uIGFuZCBTZWN1cmUgRW1haWwgQ0ECEB6M1ZwZdZU7LrAIdurulmUwOAYJKoZIhvcNAQEHMCug",$bCrlf)
$oSb.AppendLine("DzANBglghkgBZQMEAgEFAKEYMBYGCSqGSIb3DQEBCDAJBgUrDgMCGgUABIIBAK/BZG/iXJ8az7zL",$bCrlf)
$oSb.AppendLine("8EQ77mc+oDPQ4w1hyytK2ip4djkPVvTfYhcoDQ+G/DBU+urJfrVBi5H9gmpXwYyfKlyUxBVRVEJl",$bCrlf)
$oSb.AppendLine("V/V5QQi4JmNTFbmgWh5tp9zDS98l6A2Va4Zs0Wy/owGLfvwitlxd1dsfVAV2hmBYS24BMpNcty5/",$bCrlf)
$oSb.AppendLine("0atcKYmSou13G78ztTKdMy1tECgZy8kerMsPdDQbSxEZkT3KpQ8C5uEQqYF3bIVaeZzha/Ywieh/",$bCrlf)
$oSb.AppendLine("tvO0T4aAmeJufwkNdVECmU7kuhnNaVPXknFl7jeibTl6zA/VcJKBKcIYT9FRC7KjdooI8q+jtQ/V",$bCrlf)
$oSb.AppendLine("k6RP4POaowkFg1QWRPEWeqIwTAYJKoZIhvcNAQcBMB0GCWCGSAFlAwQBAgQQEEFQduqeJqXQXzy4",$bCrlf)
$oSb.AppendLine("JpkoDoAgdldJDB9zEkpMpgr5/fR2iLvh5kC6BPfhOYjsawBY4Ok=",$bCrlf)
$oSb.AppendLine("-----END PKCS7-----",$bCrlf)

$oDecrypt = ObjCreate("Chilkat.Crypt2")
$oDecrypt.CryptAlgorithm = "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.
$bSuccess = $oDecrypt.SetDecryptCert($oCert)

$oDecrypt.EncodingMode = "base64"
Local $sDecryptedText = $oDecrypt.DecryptStringENC($oSb.GetBetween("-----BEGIN PKCS7-----","-----END PKCS7-----"))

ConsoleWrite($sDecryptedText & @CRLF)