(Perl) Aadhaar Paperless Offline e-kyc

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.

For more information, see https://uidai.gov.in/ecosystem/authentication-devices-documents/about-aadhaar-paperless-offline-e-kyc.html

Chilkat Perl Downloads Perl Module for Windows, MacOS, Linux, Alpine Linux, Solaris

use chilkat();

# 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".
$zip = chilkat::CkZip->new();
$success = $zip->OpenZip("qa_data/xml_dsig/offline_paperless_kyc.zip");
if ($success == 0) {
    print $zip->lastErrorText() . "\r\n";
    exit;
}

# The .zip should contain 1 XML file.
# entry is a ZipEntry
$entry = $zip->GetEntryByIndex(0);
if ($zip->get_LastMethodSuccess() == 0) {
    print $zip->lastErrorText() . "\r\n";
    exit;
}

# To get the contents, we need to specify the Share Phrase.
$sharePhrase = 'Lock@487';
$zip->put_DecryptPassword($sharePhrase);

$bdXml = chilkat::CkBinData->new();
# The XML file will be unzipped into the bdXml object.
$success = $entry->UnzipToBd($bdXml);
if ($success == 0) {
    print $entry->lastErrorText() . "\r\n";

    exit;
}

# First verify the XML digital signature.
$dsig = chilkat::CkXmlDSig->new();
$success = $dsig->LoadSignatureBd($bdXml);
if ($success != 1) {
    print $dsig->lastErrorText() . "\r\n";
    exit;
}

# 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.
$cert = chilkat::CkCert->new();
$success = $cert->LoadFromFile("qa_data/xml_dsig/uidai_auth_sign_prod_2023.cer");
if ($success != 1) {
    print $cert->lastErrorText() . "\r\n";
    exit;
}

# Get the certificate's public key.
# pubKey is a PublicKey
$pubKey = $cert->ExportPublicKey();
$success = $dsig->SetPublicKey($pubKey);

# The XML in this example contains only 1 signature.
$bVerifyReferenceDigests = 1;
$bVerified = $dsig->VerifySignature($bVerifyReferenceDigests);
if ($bVerified == 0) {
    print $dsig->lastErrorText() . "\r\n";
    print "The signature was not valid." . "\r\n";
    exit;
}

print "The XML digital signature is valid." . "\r\n";

# 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.

$crypt = chilkat::CkCrypt2->new();
$crypt->put_HashAlgorithm("sha256");
$crypt->put_EncodingMode("hexlower");

$strToHash = '1234567890Lock@487';
$bdHash = chilkat::CkBinData->new();
$success = $bdHash->AppendString($strToHash,"utf-8");

# 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"
$numTimesToHash = 9;

for ($i = 1; $i <= $numTimesToHash; $i++) {
    $tmpStr = $crypt->hashBdENC($bdHash);
    $bdHash->Clear();
    $bdHash->AppendString($tmpStr,"utf-8");
}

print "Computed Mobile hash = " . $bdHash->getString("utf-8") . "\r\n";

# Let's get the mobile hash stored in the XML and compare it with our computed hash.
$xml = chilkat::CkXml->new();
$success = $xml->LoadBd($bdXml,1);
$m_hash = $xml->chilkatPath("UidData|Poi|(m)");

print "Stored Mobile hash   = " . $m_hash . "\r\n";

# Now do the same thing for the email hash:

$strToHash = 'abc@gm.comLock@487';
$bdHash->Clear();
$success = $bdHash->AppendString($strToHash,"utf-8");

for ($i = 1; $i <= $numTimesToHash; $i++) {
    $tmpStr = $crypt->hashBdENC($bdHash);
    $bdHash->Clear();
    $bdHash->AppendString($tmpStr,"utf-8");
}

print "Computed Email hash = " . $bdHash->getString("utf-8") . "\r\n";

$e_hash = $xml->chilkatPath("UidData|Poi|(e)");
print "Stored Email hash   = " . $e_hash . "\r\n";