CkPython

RSA Sign Binary Data and Verify (Recover the Original Data)

See more RSA Examples

Demonstrates how to RSA sign binary data and then verify/recover the original data.

Note: This example uses methods introduced in Chilkat v9.5.0.77.

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.

# Load an RSA private key for signing.
privKey = chilkat.CkPrivateKey()
success = privKey.LoadEncryptedPemFile("qa_data/pem/rsa_passwd.pem","passwd")
if (success == False):
    print(privKey.lastErrorText())
    sys.exit()

rsa = chilkat.CkRsa()
rsa.UsePrivateKey(privKey)

# We have some binary data (in hex) to sign
originalData = "0102030405060708090A"
bd = chilkat.CkBinData()
bd.AppendEncoded(originalData,"hex")

# If successful, the contents of bd are replaced with the RSA signature.
success = rsa.SignRawBd(bd)
if (success == False):
    print(rsa.lastErrorText())
    sys.exit()

# Show the RSA signature in base64
print(bd.getEncoded("base64"))

# ------------------------------------------
# Get the public key from the private key
pubKey = chilkat.CkPublicKey()
privKey.ToPublicKey(pubKey)

# Verify the signature and extract the original data.
rsa2 = chilkat.CkRsa()
rsa2.UsePublicKey(pubKey)

bVerified = rsa2.VerifyRawBd(bd)
print("signature verified: " + str(bVerified))

# Show the original data:
print("original data: " + bd.getEncoded("hex"))