Perl Requires Chilkat v11.0.0+

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. Chilkat2 Perl

use strict;
use warnings;
use Chilkat2;

# 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".
my $zip = Chilkat2::Zip->new;
my $success = $zip->OpenZip('qa_data/xml_dsig/offline_paperless_kyc.zip');
if (!$success) {
    print $zip->LastErrorText, "\n";
    exit;
}

# The .zip should contain 1 XML file.
my $entry = Chilkat2::ZipEntry->new;
$success = $zip->EntryAt(0, $entry);
if (!$success) {
    print $zip->LastErrorText, "\n";
    exit;
}

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

my $bdXml = Chilkat2::BinData->new;
# The XML file will be unzipped into the bdXml object.
$success = $entry->UnzipToBd($bdXml);
if (!$success) {
    print $entry->LastErrorText, "\n";
    exit;
}

# First verify the XML digital signature.
my $dsig = Chilkat2::XmlDSig->new;
$success = $dsig->LoadSignatureBd($bdXml);
if (!$success) {
    print $dsig->LastErrorText, "\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.
my $cert = Chilkat2::Cert->new;
$success = $cert->LoadFromFile('qa_data/xml_dsig/uidai_auth_sign_prod_2023.cer');
if (!$success) {
    print $cert->LastErrorText, "\n";
    exit;
}

# Get the certificate's public key.
my $pubKey = Chilkat2::PublicKey->new;
$cert->GetPublicKey($pubKey);

$dsig->SetPublicKey($pubKey);

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

print "The XML digital signature is valid.\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.

my $crypt = Chilkat2::Crypt2->new;
$crypt->HashAlgorithm('sha256');
$crypt->EncodingMode('hexlower');

my $strToHash = '1234567890Lock@487';
my $bdHash = Chilkat2::BinData->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"
my $numTimesToHash = 9;
for my $i (1 .. $numTimesToHash) {
    my $tmpStr = $crypt->HashBdENC($bdHash);
    $bdHash->Clear();
    $bdHash->AppendString($tmpStr, 'utf-8');
}

print 'Computed Mobile hash = ', $bdHash->GetString('utf-8'), "\n";

# Let's get the mobile hash stored in the XML and compare it with our computed hash.
my $xml = Chilkat2::Xml->new;
$success = $xml->LoadBd($bdXml, 1);
my $m_hash = $xml->ChilkatPath('UidData|Poi|(m)');

print 'Stored Mobile hash   = ', $m_hash, "\n";

# Now do the same thing for the email hash:

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

for my $i (1 .. $numTimesToHash) {
    my $tmpStr = $crypt->HashBdENC($bdHash);
    $bdHash->Clear();
    $bdHash->AppendString($tmpStr, 'utf-8');
}

print 'Computed Email hash = ', $bdHash->GetString('utf-8'), "\n";

my $e_hash = $xml->ChilkatPath('UidData|Poi|(e)');
print 'Stored Email hash   = ', $e_hash, "\n";