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Chilkat2-Python

RSA Sign String using Private Key of Certificate Type A3 (smart card / token)

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Demonstrates RSA signing a string using the private key of a certificate type A3 (smart card, token).

Note: This is a Windows-only example.

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Chilkat2-Python
import sys
import chilkat2

success = False

# First get the A3 certificate that was installed on the Windows system.
certStore = chilkat2.CertStore()

thumbprint = "12c1dd8015f3f03f7b1fa619dc24e2493ca8b4b2"

# This is specific to Windows because it is opening the Windows Current-User certificate store.
bReadOnly = True
success = certStore.OpenCurrentUserStore(bReadOnly)
if (success != True):
    print(certStore.LastErrorText)
    sys.exit()

# Find the certificate with the desired thumbprint
# (There are many ways to locate a certificate.  This example chooses to find by thumbprint.)
json = chilkat2.JsonObject()
json.UpdateString("thumbprint",thumbprint)

cert = chilkat2.Cert()
success = certStore.FindCert(json,cert)
if (success == False):
    print("Failed to find the certificate.")
    sys.exit()

print("Found: " + cert.SubjectCN)

rsa = chilkat2.Rsa()

# Provide the cert's private key
bUsePrivateKey = True
success = rsa.SetX509Cert(cert,bUsePrivateKey)
if (success != True):
    print(rsa.LastErrorText)
    sys.exit()

# Return the RSA signature in base64 encoded form.
rsa.EncodingMode = "base64"

# Sign the utf-8 byte representation of the string.
rsa.Charset = "utf-8"

# You can also choose other hash algorithms, such as SHA-1.
sigBase64 = rsa.SignStringENC("text to sign","SHA-256")
if (rsa.LastMethodSuccess != True):
    print(rsa.LastErrorText)
    sys.exit()

print("Base64 signature: " + sigBase64)