(Chilkat2-Python) Sign JSON (or any Text) to Create a Detached PKCS7 Signature

Demonstrates how to sign JSON or any string using a certificate + private key from a .p12/.pfx to create a detached PKCS7 signature. (A detached signature is one that does not embed the original signed data.)

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import sys
import chilkat2

# This example assumes the Chilkat API to have been previously unlocked.
# See Global Unlock Sample for sample code.

crypt = chilkat2.Crypt2()

cert = chilkat2.Cert()
success = cert.LoadPfxFile("qa_data/pfx/cert_test123.pfx","test123")
if (success != True):
    print(cert.LastErrorText)
    sys.exit()

# Tell the crypt component to use this cert.
success = crypt.SetSigningCert(cert)
if (success != True):
    print(crypt.LastErrorText)
    sys.exit()

crypt.HashAlgorithm = "sha256"

# By default, all the certs in the chain of authentication are included in the signature.
# If desired, we can choose to only include the signing certificate:
crypt.IncludeCertChain = False

# Create the detached signature, which does NOT contain the original data.
# To create a PKCS7 signature that contains the original data, see CAdES Sign JSON
crypt.Charset = "utf-8"

stringToSign = "{ \"abc\": 123}"
# detachedSig is a memoryview
detachedSig = crypt.SignString(stringToSign)
if (crypt.LastMethodSuccess == False):
    print(crypt.LastErrorText)
    sys.exit()

# Verify the signature against the original data.
verified = crypt.VerifyString(stringToSign,detachedSig)
if (verified == False):
    print(crypt.LastErrorText)
    sys.exit()

print("Success!")