(Excel) RSAES-OAEP Encrypt/Decrypt Binary Data with AES-128 and SHA56

Demonstrates the use of the new EncryptBd and DecryptBd methods introduced in Chilkat v9.5.0.67 to create a PKCS7/CMS (Cryptographic Message Syntax) message using RSAES-OAEP with AES-128 and SHA256.

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

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' This example requires the Chilkat Crypt API to have been previously unlocked.
' See Unlock Chilkat Crypt for sample code.

' Load a small JPG file to be encrypted/decrypted.
Dim jpgBytes As Chilkat.BinData
Set jpgBytes = Chilkat.NewBinData

success = jpgBytes.LoadFile("qa_data/jpg/starfish20.jpg")
If (success <> True) Then
    Debug.Print "Failed to load JPG file."
    Exit Sub
End If

' Show the unencrypted JPG bytes in Base64 format.
' (The "base64_mime" encoding was added in Chilkat v9.5.0.67.
' The "base64" encoding emits a single line of base64, whereas
' "base64_mime" will emit multi-line base64 as it would appear
' in MIME.)
Debug.Print jpgBytes.GetEncoded("base64_mime")

' Sample base64_mime JPG data:

' /9j/4AAQSkZJRgABAQEASABIAAD//gAmRmlsZSB3cml0dGVuIGJ5IEFkb2JlIFBob3Rvc2hvcD8g
' NC4w/9sAQwAQCwwODAoQDg0OEhEQExgoGhgWFhgxIyUdKDozPTw5Mzg3QEhcTkBEV0U3OFBtUVdf
' YmdoZz5NcXlwZHhcZWdj/9sAQwEREhIYFRgvGhovY0I4QmNjY2NjY2NjY2NjY2NjY2NjY2NjY2Nj
' Y2NjY2NjY2NjY2NjY2NjY2NjY2NjY2NjY2Nj/8IAEQgAFAAUAwERAAIRAQMRAf/EABcAAAMBAAAA
' AAAAAAAAAAAAAAIDBAX/xAAYAQADAQEAAAAAAAAAAAAAAAABAgMEAP/aAAwDAQACEAMQAAAB2kZY
' NNEijWKddfTmLgALWH//xAAbEAACAgMBAAAAAAAAAAAAAAABAgMRAAQSE//aAAgBAQABBQL0XqN+
' pM2aqJGMiqFFCyg7z//EABwRAAICAgMAAAAAAAAAAAAAAAERAAIQIQMSUf/aAAgBAwEBPwHqU5aq
' Axx+y1tMQl4elj//xAAcEQEAAQUBAQAAAAAAAAAAAAABEQACEBIhA1H/2gAIAQIBAT8B3Bhqy7Zc
' enyiwmGgDhiOzj//xAAdEAABAwUBAAAAAAAAAAAAAAABAAIREBIhIkFR/9oACAEBAAY/ArZyn+Cg
' xtxWuJaoCnqDuin/xAAcEAABBAMBAAAAAAAAAAAAAAABABEhYRAxQVH/2gAIAQEAAT8hkEwPUUR9
' DYfE4nxtRpIkBTsayuALIiuY/9oADAMBAAIAAwAAABDWPTsf/8QAGhEAAwADAQAAAAAAAAAAAAAA
' AAEREDFBIf/aAAgBAwEBPxC0DVPcWm+Ce4OesrkE6bjH/8QAGBEBAQEBAQAAAAAAAAAAAAAAAREA
' QRD/2gAIAQIBAT8QahMiOc8YgSrnTY3ELclHXn//xAAcEAEBAAIDAQEAAAAAAAAAAAABEQAhMUFx
' EFH/2gAIAQEAAT8Qn3igmSZSj+c4N4zapMy9IjFV98wncN2iuLFsCEbDGxQkI6RO/n//2Q==

Dim crypt As Chilkat.Crypt2
Set crypt = Chilkat.NewCrypt2

' Specify the encryption to be used.
' "pki" indicates "Public Key Infrastructure" and will create a PKCS7/CMS message.
crypt.CryptAlgorithm = "pki"
crypt.Pkcs7CryptAlg = "aes"
crypt.KeyLength = 128
crypt.OaepHash = "sha256"
crypt.OaepPadding = True

' A certificate is needed as the encryption key..
Dim cert As Chilkat.Cert
Set cert = Chilkat.NewCert
success = cert.LoadFromFile("qa_data/rsaes-oaep/cert.pem")
If (success <> True) Then
    Debug.Print cert.LastErrorText
    Exit Sub
End If

' Tell the crypt object to use the certificate.
Dim success As Boolean
success = crypt.SetEncryptCert(cert)

' Do the in-place RSAES-OAEP encryption.
' The contents of jpgBytes are replaced with the CMS message.
success = crypt.EncryptBd(jpgBytes)
If (success <> True) Then
    Debug.Print crypt.LastErrorText
    Exit Sub
End If

' Examine the JPG bytes again.  The bytes should be different because they are encrypted:
Debug.Print jpgBytes.GetEncoded("base64_mime")

' Sample CMS message:
' This CMS message can be copy-and-pasted into the online web form
' at https://lapo.it/asn1js/   to verify the algorithms used.

' MIIFDAYJKoZIhvcNAQcDoIIE/TCCBPkCAQAxggGgMIIBnAIBADB1MGgxCzAJBgNVBAYTAlVTMQsw
' CQYDVQQIDAJJTDEQMA4GA1UEBwwHV2hlYXRvbjEhMB8GA1UECgwYSW50ZXJuZXQgV2lkZ2l0cyBQ
' dHkgTHRkMRcwFQYDVQQDDA5DaGlsa2F0V2lkZ2V0cwIJAMRwugDmvniwMBwGCSqGSIb3DQEBBzAP
' oA0wCwYJYIZIAWUDBAIBBIIBAHyWLgkJfIvoA3cYEAR/uHfA7uoi4eQXHl2woQAd6W5BbUNVBcYD
' zuCTTOTWo1e7Uh0j0AhMZvVQf3+cngTiimzKwIZ2LNuNAgYOhrO/7coHyB22ImVetncUpCsAv/u7
' 2tYp1dO36T56K+2hMELwcQXTj6v5ODO6a3emdCjITCjHhlYePvq2l0HyU2ALG5RFB6ldk9imhKzn
' 6gfcijfH65S+KfMRlFBCXFu5nCBKmi8Ywo8Ue0rFssUDKLCjCeQNY52symiDbN/d06K/luOUwVhY
' 1KQffdIKmTrZUugw+FaoQRq0xGj39T/sYu8qCinNZu/vPdUmxcXszSaSVJ/LGwcwggNOBgkqhkiG
' 9w0BBwEwHQYJYIZIAWUDBAECBBDLnqRASqqnNUV2IiDkTRl/gIIDIPRaxdKEjhR5RD7pc7yI5j7N
' TioZNvuMETdHWgHy7eOGz+1hP7fObk/RI0mtQx7IPEjkxaduNbXNzTpXAVRVj4Fw1zzXlqh9UPwt
' p3TN3NsVRPQ5GmQ+cnPTSZD8i3i8ru8WFHyj1M6vyA0phrEGltKgqsZbb+OkuO5qG3laJv4XGkmn
' 039pPGSTydQzW+HAp/hsJZLEMwdngXToi854ytjEk+ahCkeOz+d2MAfXZAR+nBCkmAmCQ9SDVTqH
' FVJOAV2WrKBqNv4+iMn63f7QeoVIjk0QTE8D2iRsUiFYjy4ICaUpplLJEewneH5l0W40KA2+mOep
' lIrvWnaX2H8ltOEBGD6Jng7i6p/Q4Lr+Y+HBYIHsBPLox3A4NOh/b0MZcyBr/AV2CsIwkIUGLlYl
' /3rnpl7dRTuHP+fe1lDQVLAxD+U0c73sW7vOALhEe2t2Ae3ayukWPRyfXK9FNHAMhcOI4stHNSwx
' o2fHa+ctTpPh0V5CHY/ELAKKkrH3nW954pk52tc8Xt6CnzVO5ry/ndcmTlQA0PkG6CK98TE9hCTA
' hBdSL4/gVFgi9c35I6VXieY9kJe5ICljw5Ftm5yqTwlJIxGU3Z/WeIYBF4uyMegG75AQ9Md9tX0h
' w8OOu2b6sIvxOZ+durIrYQDlXUXU/IR9exzAlYFENNBPhBgtDsWKSx5gcp+32kC5wtSYSiy3JxNt
' 0W1yEJz8JGZXhuUvRXjwf+AjS4+/o82WTNXVLVKZ0TP50NVvtf9QqWuXvK/kDDPx6w+abK/aqdAs
' QSL7wCxOosR2YUPWbXtwGhyHbIfAwWXijO2RnrqKeXL25Ywg16LQUTHq9Mlbgfw/tx3l5pjrmqFC
' e9t9aaU6kDZqyyfRDOeWwkuDIsT90ulazbed2apgUXYj6AVVvMiC1pRld9wSuHH0vW0x5VsNbmXy
' EY0NJlJY6II/1szy3bpiP6MsqFveCyCX8rM7UgGgpMNbvWPnsX0F/0eJywIrXrnQYXpvfgghIrlr
' qu/ftXWypfcfvATxme+cN2EBsCDhq4VcMgB6JY3ykv6P8PK/QpMTbu4Y

' To decrypt, we'll need the cert with private key.  
' (The certificate alone contains only the public key.)
' Provide the required cert + private key from a PFX (.pfx/.p12) file.
success = crypt.AddPfxSourceFile("qa_data/rsaes-oaep/cert_plus_privatekey.pfx","PFX_PASSWORD")
If (success <> True) Then
    Debug.Print crypt.LastErrorText
    Exit Sub
End If

' Decrypt to restore back to the original:
success = crypt.DecryptBd(jpgBytes)
If (success <> True) Then
    Debug.Print crypt.LastErrorText
    Exit Sub
End If

Debug.Print jpgBytes.GetEncoded("base64_mime")