Python Requires Chilkat v11.7.0+

Replace the Authenticode Signature of an Already Signed File

See more Code Signing Examples

Demonstrates how to sign a file that already has an Authenticode signature, for example to sign it with a renewed code signing certificate. Starting in Chilkat v11.7.0, AddSignature removes the existing signature and replaces it with the new one. Before v11.7.0, signing an already signed EXE or DLL added a second signature entry instead. Python

import sys
import chilkat2

success = False

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

# Starting in Chilkat v11.7.0, AddSignature replaces the signature of a file that is already signed.
# (Before v11.7.0, signing an already signed EXE or DLL added a second signature entry
# instead of replacing the first.)
# 
# This applies to every supported file type: EXE, DLL, MSI, PowerShell, and VBScript.

path = "C:/someDir/MyApp.exe"

codeSign = chilkat2.CodeSign()
sigInfo = chilkat2.JsonObject()
signerCert = chilkat2.Cert()

# Find out who signed the file.
valid = codeSign.VerifySignature(path,sigInfo)
if (valid == True):
    codeSign.GetSignerCert(signerCert)
    print("currently signed by: " + signerCert.SubjectCN)
    print("certificate valid until: " + signerCert.ValidToStr)
else:
    print("The file is not signed, or its signature is not valid.")

# Load the certificate to sign with.  It must have access to its private key.
cert = chilkat2.Cert()
success = cert.LoadPfxFile("C:/someDir/myNewCodeSigningCert.pfx","pfx password")
if (success == False):
    print(cert.LastErrorText)
    sys.exit()

# Sign with SHA256, and ask a timestamp authority for a timestamp.  A timestamp lets the
# signature continue to validate after the code signing certificate has expired.
# 
# {
#   "hashAlg": "sha256",
#   "timestampToken": {
#     "enabled": true,
#     "tsaUrl": "http://timestamp.digicert.com",
#     "requestTsaCert": true,
#     "hashAlg": "sha256"
#   }
# }
json = chilkat2.JsonObject()
json.UpdateString("hashAlg","sha256")
json.UpdateBool("timestampToken.enabled",True)
json.UpdateString("timestampToken.tsaUrl","http://timestamp.digicert.com")
json.UpdateBool("timestampToken.requestTsaCert",True)
json.UpdateString("timestampToken.hashAlg","sha256")

# Sign the file.  It is not necessary to call RemoveSignature first:
# the existing signature is removed and the new signature takes its place.
success = codeSign.AddSignature(path,cert,json)
if (success == False):
    print(codeSign.LastErrorText)
    sys.exit()

# The file now has one signature, made with the new certificate.
valid = codeSign.VerifySignature(path,sigInfo)
if (valid == False):
    print(codeSign.LastErrorText)
    sys.exit()

success = codeSign.GetSignerCert(signerCert)
if (success == False):
    print(codeSign.LastErrorText)
    sys.exit()

print("now signed by: " + signerCert.SubjectCN)
print("certificate valid until: " + signerCert.ValidToStr)