DataFlex

Aadhaar Paperless Offline e-kyc

See more XML Digital Signatures Examples

Opens an encrypted .zip containing Aadhaar Paperless Offline e-KYC XML. Gets the XML and validates the digital signature. Then computes the hash for the mobile number and Email ID. DataFlex

Use ChilkatAx-win32.pkg

Procedure Test
    Boolean iSuccess
    Handle hoZip
    Variant vEntry
    Handle hoEntry
    String sSharePhrase
    Variant vBdXml
    Handle hoBdXml
    Handle hoDsig
    Handle hoCert
    Variant vPubKey
    Handle hoPubKey
    Boolean iBVerifyReferenceDigests
    Boolean iBVerified
    Handle hoCrypt
    String sStrToHash
    Variant vBdHash
    Handle hoBdHash
    Integer iNumTimesToHash
    Integer i
    String sTmpStr
    Handle hoXml
    String sM_hash
    String sTmpStr
    String sE_hash
    String sTemp1

    Move False To iSuccess

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

    // Open the .zip containing the Aadhaar Paperless Offline e-KYC XML.
    // The .zip is encrypted using the "Share Phrase".
    Get Create (RefClass(cComChilkatZip)) To hoZip
    If (Not(IsComObjectCreated(hoZip))) Begin
        Send CreateComObject of hoZip
    End
    Get ComOpenZip Of hoZip "qa_data/xml_dsig/offline_paperless_kyc.zip" To iSuccess
    If (iSuccess = False) Begin
        Get ComLastErrorText Of hoZip To sTemp1
        Showln sTemp1
        Procedure_Return
    End

    // The .zip should contain 1 XML file.
    Get Create (RefClass(cComChilkatZipEntry)) To hoEntry
    If (Not(IsComObjectCreated(hoEntry))) Begin
        Send CreateComObject of hoEntry
    End
    Get pvComObject of hoEntry to vEntry
    Get ComEntryAt Of hoZip 0 vEntry To iSuccess
    If (iSuccess = False) Begin
        Get ComLastErrorText Of hoZip To sTemp1
        Showln sTemp1
        Procedure_Return
    End

    // To get the contents, we need to specify the Share Phrase.
    Move "Lock@487" To sSharePhrase
    Set ComDecryptPassword Of hoZip To sSharePhrase

    Get Create (RefClass(cComChilkatBinData)) To hoBdXml
    If (Not(IsComObjectCreated(hoBdXml))) Begin
        Send CreateComObject of hoBdXml
    End
    // The XML file will be unzipped into the bdXml object.
    Get pvComObject of hoBdXml to vBdXml
    Get ComUnzipToBd Of hoEntry vBdXml To iSuccess
    If (iSuccess = False) Begin
        Get ComLastErrorText Of hoEntry To sTemp1
        Showln sTemp1
        Procedure_Return
    End

    // First verify the XML digital signature.
    Get Create (RefClass(cComChilkatXmlDSig)) To hoDsig
    If (Not(IsComObjectCreated(hoDsig))) Begin
        Send CreateComObject of hoDsig
    End
    Get pvComObject of hoBdXml to vBdXml
    Get ComLoadSignatureBd Of hoDsig vBdXml To iSuccess
    If (iSuccess = False) Begin
        Get ComLastErrorText Of hoDsig To sTemp1
        Showln sTemp1
        Procedure_Return
    End

    // The UIDAI XML signature does not contain the KeyInfo, so we must load the uidai certificate
    // and indicate that its public key is to be used for verifying the signature.
    Get Create (RefClass(cComChilkatCert)) To hoCert
    If (Not(IsComObjectCreated(hoCert))) Begin
        Send CreateComObject of hoCert
    End
    Get ComLoadFromFile Of hoCert "qa_data/xml_dsig/uidai_auth_sign_prod_2023.cer" To iSuccess
    If (iSuccess = False) Begin
        Get ComLastErrorText Of hoCert To sTemp1
        Showln sTemp1
        Procedure_Return
    End

    // Get the certificate's public key.
    Get Create (RefClass(cComChilkatPublicKey)) To hoPubKey
    If (Not(IsComObjectCreated(hoPubKey))) Begin
        Send CreateComObject of hoPubKey
    End
    Get pvComObject of hoPubKey to vPubKey
    Get ComGetPublicKey Of hoCert vPubKey To iSuccess

    Get pvComObject of hoPubKey to vPubKey
    Get ComSetPublicKey Of hoDsig vPubKey To iSuccess

    // The XML in this example contains only 1 signature.
    Move True To iBVerifyReferenceDigests
    Get ComVerifySignature Of hoDsig iBVerifyReferenceDigests To iBVerified
    If (iBVerified = False) Begin
        Get ComLastErrorText Of hoDsig To sTemp1
        Showln sTemp1
        Showln "The signature was not valid."
        Procedure_Return
    End

    Showln "The XML digital signature is valid."

    // Let's compute the hash for the Mobile Number.

    // 	Hashing logic for Mobile Number :
    // 	Sha256(Sha256(Mobile+SharePhrase))*number of times last digit of Aadhaar number
    // 	(Ref ID field contains last 4 digits).
    // 
    // 	Example :
    // 	Mobile: 1234567890
    // 	Aadhaar Number:XXXX XXXX 3632
    // 	Passcode : Lock@487
    // 	Hash: Sha256(Sha256(1234567890Lock@487))*2
    // 	In case of Aadhaar number ends with Zero we will hashed one time.

    Get Create (RefClass(cComChilkatCrypt2)) To hoCrypt
    If (Not(IsComObjectCreated(hoCrypt))) Begin
        Send CreateComObject of hoCrypt
    End
    Set ComHashAlgorithm Of hoCrypt To "sha256"
    Set ComEncodingMode Of hoCrypt To "hexlower"

    Move "1234567890Lock@487" To sStrToHash
    Get Create (RefClass(cComChilkatBinData)) To hoBdHash
    If (Not(IsComObjectCreated(hoBdHash))) Begin
        Send CreateComObject of hoBdHash
    End
    Get ComAppendString Of hoBdHash sStrToHash "utf-8" To iSuccess

    // Hash a number of times equal to the last digit of your Aadhaar number.
    // If the Aadhaar number ends with 0, then hash one time.
    // For this example, we'll just set the number of times to hash
    // for the case where an Aadhaar number ends in "9"
    Move 9 To iNumTimesToHash

    For i From 1 To iNumTimesToHash
        Get pvComObject of hoBdHash to vBdHash
        Get ComHashBdENC Of hoCrypt vBdHash To sTmpStr
        Get ComClear Of hoBdHash To iSuccess
        Get ComAppendString Of hoBdHash sTmpStr "utf-8" To iSuccess
    Loop

    Get ComGetString Of hoBdHash "utf-8" To sTemp1
    Showln "Computed Mobile hash = " sTemp1

    // Let's get the mobile hash stored in the XML and compare it with our computed hash.
    Get Create (RefClass(cComChilkatXml)) To hoXml
    If (Not(IsComObjectCreated(hoXml))) Begin
        Send CreateComObject of hoXml
    End
    Get pvComObject of hoBdXml to vBdXml
    Get ComLoadBd Of hoXml vBdXml True To iSuccess
    Get ComChilkatPath Of hoXml "UidData|Poi|(m)" To sM_hash

    Showln "Stored Mobile hash   = " sM_hash

    // Now do the same thing for the email hash:

    Move "abc@gm.comLock@487" To sStrToHash
    Get ComClear Of hoBdHash To iSuccess
    Get ComAppendString Of hoBdHash sStrToHash "utf-8" To iSuccess

    For i From 1 To iNumTimesToHash
        Get pvComObject of hoBdHash to vBdHash
        Get ComHashBdENC Of hoCrypt vBdHash To sTmpStr
        Get ComClear Of hoBdHash To iSuccess
        Get ComAppendString Of hoBdHash sTmpStr "utf-8" To iSuccess
    Loop

    Get ComGetString Of hoBdHash "utf-8" To sTemp1
    Showln "Computed Email hash = " sTemp1

    Get ComChilkatPath Of hoXml "UidData|Poi|(e)" To sE_hash
    Showln "Stored Email hash   = " sE_hash


End_Procedure