(DataFlex) ClickBank Decrypt Instant Notification

Demonstrates how to decrypt a ClickBank instant notification. See Instant Notification Service for more information and alternative code snippets.

Chilkat ActiveX Downloads ActiveX for 32-bit and 64-bit Windows

Use ChilkatAx-win32.pkg

Procedure Test
    String sSecretKey
    String sJsonStr
    Handle hoJson
    Boolean iSuccess
    Variant vBdNotif
    Handle hoBdNotif
    Handle hoBdIv
    Handle hoCrypt
    String sHexSha1
    Handle hoBdKey
    String sTemp1

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

    // secret key from your ClickBank account
    Move "MY_SECRET_KEY" To sSecretKey

    Move '{"notification":"BASE64_NOTIFICATION","iv":"BASE64_IV"}' To sJsonStr

    Get Create (RefClass(cComChilkatJsonObject)) To hoJson
    If (Not(IsComObjectCreated(hoJson))) Begin
        Send CreateComObject of hoJson
    End
    Get ComLoad Of hoJson sJsonStr To iSuccess

    // Get the encrypted notification (binary) and IV from the JSON.
    Get Create (RefClass(cComChilkatBinData)) To hoBdNotif
    If (Not(IsComObjectCreated(hoBdNotif))) Begin
        Send CreateComObject of hoBdNotif
    End
    Get Create (RefClass(cComChilkatBinData)) To hoBdIv
    If (Not(IsComObjectCreated(hoBdIv))) Begin
        Send CreateComObject of hoBdIv
    End

    Get ComStringOf Of hoJson "notification" To sTemp1
    Get ComAppendEncoded Of hoBdNotif sTemp1 "base64" To iSuccess
    Get ComStringOf Of hoJson "iv" To sTemp1
    Get ComAppendEncoded Of hoBdIv sTemp1 "base64" To iSuccess

    // Get an SHA1 digest (as a hex string) of the secret key.
    // A SHA1 digest is 20 bytes.  Therefore the hex string is 40 chars.
    // Treat each us-ascii char as a binary byte of the secret key.
    // 256-bit AES needs a 256-bit key, which is 32-bytes.  Therefore
    // use the 1st 32 us-ascii chars of the hex SHA1 as the AES secret key.

    Get Create (RefClass(cComChilkatCrypt2)) To hoCrypt
    If (Not(IsComObjectCreated(hoCrypt))) Begin
        Send CreateComObject of hoCrypt
    End
    // Because we're using the hex string as the actual AES key, it matters whether the hex is uppercase or lowercase.
    // We want lowercase.
    Set ComEncodingMode Of hoCrypt To "hex_lower"
    Set ComHashAlgorithm Of hoCrypt To "sha1"
    Get ComHashStringENC Of hoCrypt sSecretKey To sHexSha1
    Showln sHexSha1

    // Treat the hex string as binary data for the AES key..
    Get Create (RefClass(cComChilkatBinData)) To hoBdKey
    If (Not(IsComObjectCreated(hoBdKey))) Begin
        Send CreateComObject of hoBdKey
    End
    Get ComAppendString Of hoBdKey sHexSha1 "us-ascii" To iSuccess
    Get ComRemoveChunk Of hoBdKey 32 8 To iSuccess

    Set ComKeyLength Of hoCrypt To 256
    Set ComCryptAlgorithm Of hoCrypt To "aes"
    Set ComCipherMode Of hoCrypt To "cbc"

    // We can use any encoding because were just getting the binary bytes in an encoding, and then setting from the same encoding.
    // We'll just use base64..
    Get ComGetEncoded Of hoBdIv "base64" To sTemp1
    Send ComSetEncodedIV To hoCrypt sTemp1 "base64"
    Get ComGetEncoded Of hoBdKey "base64" To sTemp1
    Send ComSetEncodedKey To hoCrypt sTemp1 "base64"

    Get pvComObject of hoBdNotif to vBdNotif
    Get ComDecryptBd Of hoCrypt vBdNotif To iSuccess
    Get ComGetString Of hoBdNotif "utf-8" To sTemp1
    Showln "Decrypted: " sTemp1


End_Procedure