PureBasic

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

See more Encryption Examples

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.

PureBasic

IncludeFile "CkBinData.pb"
IncludeFile "CkCert.pb"
IncludeFile "CkCrypt2.pb"

Procedure ChilkatExample()

    success.i = 0

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

    ; Load a small JPG file to be encrypted/decrypted.
    jpgBytes.i = CkBinData::ckCreate()
    If jpgBytes.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    success = CkBinData::ckLoadFile(jpgBytes,"qa_data/jpg/starfish20.jpg")
    If success <> 1
        Debug "Failed to load JPG file."
        CkBinData::ckDispose(jpgBytes)
        ProcedureReturn
    EndIf

    ; 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 CkBinData::ckGetEncoded(jpgBytes,"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==

    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/CMS 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..
    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)
        CkBinData::ckDispose(jpgBytes)
        CkCrypt2::ckDispose(crypt)
        CkCert::ckDispose(cert)
        ProcedureReturn
    EndIf

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

    ; Do the in-place RSAES-OAEP encryption.
    ; The contents of jpgBytes are replaced with the CMS message.
    success = CkCrypt2::ckEncryptBd(crypt,jpgBytes)
    If success <> 1
        Debug CkCrypt2::ckLastErrorText(crypt)
        CkBinData::ckDispose(jpgBytes)
        CkCrypt2::ckDispose(crypt)
        CkCert::ckDispose(cert)
        ProcedureReturn
    EndIf

    ; Examine the JPG bytes again.  The bytes should be different because they are encrypted:
    Debug CkBinData::ckGetEncoded(jpgBytes,"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 = CkCrypt2::ckAddPfxSourceFile(crypt,"qa_data/rsaes-oaep/cert_plus_privatekey.pfx","PFX_PASSWORD")
    If success <> 1
        Debug CkCrypt2::ckLastErrorText(crypt)
        CkBinData::ckDispose(jpgBytes)
        CkCrypt2::ckDispose(crypt)
        CkCert::ckDispose(cert)
        ProcedureReturn
    EndIf

    ; Decrypt to restore back to the original:
    success = CkCrypt2::ckDecryptBd(crypt,jpgBytes)
    If success <> 1
        Debug CkCrypt2::ckLastErrorText(crypt)
        CkBinData::ckDispose(jpgBytes)
        CkCrypt2::ckDispose(crypt)
        CkCert::ckDispose(cert)
        ProcedureReturn
    EndIf

    Debug CkBinData::ckGetEncoded(jpgBytes,"base64_mime")


    CkBinData::ckDispose(jpgBytes)
    CkCrypt2::ckDispose(crypt)
    CkCert::ckDispose(cert)


    ProcedureReturn
EndProcedure