CkPython 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. CkPython

import sys
import chilkat

success = False

#  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()
success = zip.OpenZip("qa_data/xml_dsig/offline_paperless_kyc.zip")
if (success == False):
    print(zip.lastErrorText())
    sys.exit()

#  The .zip should contain 1 XML file.
entry = chilkat.CkZipEntry()
success = zip.EntryAt(0,entry)
if (success == False):
    print(zip.lastErrorText())
    sys.exit()

#  To get the contents, we need to specify the Share Phrase.
sharePhrase = "Lock@487"
zip.put_DecryptPassword(sharePhrase)

bdXml = chilkat.CkBinData()
#  The XML file will be unzipped into the bdXml object.
success = entry.UnzipToBd(bdXml)
if (success == False):
    print(entry.lastErrorText())
    sys.exit()

#  First verify the XML digital signature.
dsig = chilkat.CkXmlDSig()
success = dsig.LoadSignatureBd(bdXml)
if (success == False):
    print(dsig.lastErrorText())
    sys.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()
success = cert.LoadFromFile("qa_data/xml_dsig/uidai_auth_sign_prod_2023.cer")
if (success == False):
    print(cert.lastErrorText())
    sys.exit()

#  Get the certificate's public key.
pubKey = chilkat.CkPublicKey()
cert.GetPublicKey(pubKey)

dsig.SetPublicKey(pubKey)

#  The XML in this example contains only 1 signature.
bVerifyReferenceDigests = True
bVerified = dsig.VerifySignature(bVerifyReferenceDigests)
if (bVerified == False):
    print(dsig.lastErrorText())
    print("The signature was not valid.")
    sys.exit()

print("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.

crypt = chilkat.CkCrypt2()
crypt.put_HashAlgorithm("sha256")
crypt.put_EncodingMode("hexlower")

strToHash = "1234567890Lock@487"
bdHash = chilkat.CkBinData()
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 in range(1,(numTimesToHash)-1):
    tmpStr = crypt.hashBdENC(bdHash)
    bdHash.Clear()
    bdHash.AppendString(tmpStr,"utf-8")

print("Computed Mobile hash = " + bdHash.getString("utf-8"))

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

print("Stored Mobile hash   = " + m_hash)

#  Now do the same thing for the email hash:

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

for i in range(1,(numTimesToHash)-1):
    tmpStr = crypt.hashBdENC(bdHash)
    bdHash.Clear()
    bdHash.AppendString(tmpStr,"utf-8")

print("Computed Email hash = " + bdHash.getString("utf-8"))

e_hash = xml.chilkatPath("UidData|Poi|(e)")
print("Stored Email hash   = " + e_hash)