CkPython

RSA Sign utf-8 Bytes of String to get Base64 RSA Signature

See more Apple Keychain Examples

Demonstrates how RSA sign the utf-8 byte representation of a string to get the signature in base64 format. CkPython

import sys
import chilkat

success = False

# Assuming the smartcard/USB token is installed with the correct drivers from the manufacturer,
# this code can work on multiple platforms including Windows, MacOS, Linux, and iOS.

# Chilkat automatically detects and determines the way in which the HSM is used,
# which can be by PKCS11, Apple Keychain, Microsoft CNG / Crypto API, or ScMinidriver.

cert = chilkat.CkCert()

# Set the token/smartcard PIN prior to loading.
cert.put_SmartCardPin("123456")

# Specify the certificate by its common name.
success = cert.LoadFromSmartcard("cn=chilkat-rsa-2048")
if (success == False):
    print(cert.lastErrorText())
    sys.exit()

print("Signing with cert: " + cert.subjectCN())

# Create a string to be hashed and signed.
sb = chilkat.CkStringBuilder()
crlfLineEnding = True

for i in range(0,11):
    sb.AppendLine("This is a test.",crlfLineEnding)

rsa = chilkat.CkRsa()

# Use the certificate's private key for signing.
success = rsa.SetX509Cert(cert,True)
if (success == False):
    print(rsa.lastErrorText())
    sys.exit()

# Sign the SHA-256 hash of the utf-8 byte representation of the contents of sb
# Return the signature in base64 format.
rsa.put_EncodingMode("base64")
rsa.put_Charset("utf-8")
stringToSign = sb.getAsString()
sigBase64 = rsa.signStringENC(stringToSign,"sha256")
if (rsa.get_LastMethodSuccess() == False):
    print(rsa.lastErrorText())
    sys.exit()

print("RSA signature as base64: " + sigBase64)