(CkPython) RFC3161 Timestamp Client - Fetch from Timestamp Authority (TSA) and Verify

Sends an RFC 3161 timestamp request to a TSA (Timestamp Authority) server and validates the timestamp token response.

Note: This example requires Chilkat v9.5.0.75 or greater.

Chilkat Python Downloads install with pip pip3 install chilkat or download... Python Module for Windows, MacOS, Linux, Alpine Linux, Solaris

import sys
import chilkat

# Note: Requires Chilkat v9.5.0.75 or greater.

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

# First sha-256 hash the data that is to be timestamped.
# In this example, the data is the string "Hello World"

crypt = chilkat.CkCrypt2()
crypt.put_HashAlgorithm("sha256")
crypt.put_EncodingMode("base64")
base64Hash = crypt.hashStringENC("Hello World")

http = chilkat.CkHttp()

requestToken = chilkat.CkBinData()
optionalPolicyOid = ""
addNonce = False
requestTsaCert = True

# Create a time-stamp request token
success = http.CreateTimestampRequest("sha256",base64Hash,optionalPolicyOid,addNonce,requestTsaCert,requestToken)
if (success != True):
    print(http.lastErrorText())
    sys.exit()

# Send the time-stamp request token to the TSA.
# This is the equivalent of the following CURL command:
# curl -H "Content-Type: application/timestamp-query" --data-binary '@file.tsq' https://freetsa.org/tsr > file.tsr
tsaUrl = "https://freetsa.org/tsr"
# Another timestamp server you could try is: http://timestamp.digicert.com
tsaUrl = "http://timestamp.digicert.com"
# resp is a CkHttpResponse
resp = http.PBinaryBd("POST",tsaUrl,requestToken,"application/timestamp-query",False,False)
if (http.get_LastMethodSuccess() != True):
    print(http.lastErrorText())
    sys.exit()

# Get the timestamp reply from the HTTP response object.
timestampReply = chilkat.CkBinData()
resp.GetBodyBd(timestampReply)

# Show the base64 encoded timestamp reply.
print(timestampReply.getEncoded("base64"))

# Let's verify the timestamp reply against the TSA's cert, which we've previously downloaded.
# See https://freetsa.org/index_en.php
tsaCert = chilkat.CkCert()
success = tsaCert.LoadFromFile("qa_data/certs/freetsa.org.cer")
if (success != True):
    print(tsaCert.lastErrorText())
    sys.exit()

# The VerifyTimestampReply method will return one of the following values:
# -1:  The timestampReply does not contain a valid timestamp reply.
# -2: The  timestampReply is a valid timestamp reply, but failed verification using the public key of the tsaCert.
# 0:  Granted and verified.
# 1: Granted and verified, with mods (see RFC 3161)
# 2: Rejected.
# 3: Waiting.
# 4: Revocation Warning
# 5: Revocation Notification
pkiStatus = http.VerifyTimestampReply(timestampReply,tsaCert)
if (pkiStatus < 0):
    print(http.lastErrorText())
    sys.exit()

print("pkiStatus = " + str(pkiStatus))

# json is a CkJsonObject
json = http.LastJsonData()
json.put_EmitCompact(False)
print(json.emit())

# The LastJsonData looks like the following.
# Note: The "timestampReply.pkiStatus" portion of the LastJsonData was added in Chilkat v9.5.0.83

# Use this online tool to generate parsing code from sample JSON: 
# Generate Parsing Code from JSON

# {
#   "timestampReply": {
#     "pkiStatus": {
#       "value": 0,
#       "meaning": "granted"
#     }
#   },
#   "pkcs7": {
#     "verify": {
#       "digestAlgorithms": [
#         "sha256"
#       ],
#       "signerInfo": [
#         {
#           "cert": {
#             "serialNumber": "04CD3F8568AE76C61BB0FE7160CCA76D",
#             "issuerCN": "DigiCert SHA2 Assured ID Timestamping CA",
#             "digestAlgOid": "2.16.840.1.101.3.4.2.1",
#             "digestAlgName": "SHA256"
#           },
#           "contentType": "1.2.840.113549.1.9.16.1.4",
#           "signingTime": "200405023019Z",
#           "messageDigest": "f14zOsdnN9vyyV3HjjBiLzNDi1PF28hAFMODxNkNRZs=",
#           "signingAlgOid": "1.2.840.113549.1.1.1",
#           "signingAlgName": "RSA-PKCSV-1_5",
#           "authAttr": {
#             "1.2.840.113549.1.9.3": {
#               "name": "contentType",
#               "oid": "1.2.840.113549.1.9.16.1.4"
#             },
#             "1.2.840.113549.1.9.5": {
#               "name": "signingTime",
#               "utctime": "200405023019Z"
#             },
#             "1.2.840.113549.1.9.16.2.12": {
#               "name": "signingCertificate",
#               "der": "MBowGDAWBBQDJb1QXtqWMC3CL0+gHkwovig0xQ=="
#             },
#             "1.2.840.113549.1.9.4": {
#               "name": "messageDigest",
#               "digest": "f14zOsdnN9vyyV3HjjBiLzNDi1PF28hAFMODxNkNRZs="
#             }
#           }
#         }
#       ]
#     }
#   }
# }

signingTime = chilkat.CkDtObj()
authAttrSigningTimeUtctime = chilkat.CkDtObj()

timestampReplyPkiStatusValue = json.IntOf("timestampReply.pkiStatus.value")
timestampReplyPkiStatusMeaning = json.stringOf("timestampReply.pkiStatus.meaning")
i = 0
count_i = json.SizeOfArray("pkcs7.verify.digestAlgorithms")
while i < count_i :
    json.put_I(i)
    strVal = json.stringOf("pkcs7.verify.digestAlgorithms[i]")
    i = i + 1

i = 0
count_i = json.SizeOfArray("pkcs7.verify.signerInfo")
while i < count_i :
    json.put_I(i)
    certSerialNumber = json.stringOf("pkcs7.verify.signerInfo[i].cert.serialNumber")
    certIssuerCN = json.stringOf("pkcs7.verify.signerInfo[i].cert.issuerCN")
    certDigestAlgOid = json.stringOf("pkcs7.verify.signerInfo[i].cert.digestAlgOid")
    certDigestAlgName = json.stringOf("pkcs7.verify.signerInfo[i].cert.digestAlgName")
    contentType = json.stringOf("pkcs7.verify.signerInfo[i].contentType")
    json.DtOf("pkcs7.verify.signerInfo[i].signingTime",False,signingTime)
    messageDigest = json.stringOf("pkcs7.verify.signerInfo[i].messageDigest")
    signingAlgOid = json.stringOf("pkcs7.verify.signerInfo[i].signingAlgOid")
    signingAlgName = json.stringOf("pkcs7.verify.signerInfo[i].signingAlgName")
    authAttrContentTypeName = json.stringOf("pkcs7.verify.signerInfo[i].authAttr.\"1.2.840.113549.1.9.3\".name")
    authAttrContentTypeOid = json.stringOf("pkcs7.verify.signerInfo[i].authAttr.\"1.2.840.113549.1.9.3\".oid")
    authAttrSigningTimeName = json.stringOf("pkcs7.verify.signerInfo[i].authAttr.\"1.2.840.113549.1.9.5\".name")
    json.DtOf("pkcs7.verify.signerInfo[i].authAttr.\"1.2.840.113549.1.9.5\".utctime",False,authAttrSigningTimeUtctime)
    authAttrSigningCertificateName = json.stringOf("pkcs7.verify.signerInfo[i].authAttr.\"1.2.840.113549.1.9.16.2.12\".name")
    authAttrSigningCertificateDer = json.stringOf("pkcs7.verify.signerInfo[i].authAttr.\"1.2.840.113549.1.9.16.2.12\".der")
    authAttrMessageDigestName = json.stringOf("pkcs7.verify.signerInfo[i].authAttr.\"1.2.840.113549.1.9.4\".name")
    authAttrMessageDigestDigest = json.stringOf("pkcs7.verify.signerInfo[i].authAttr.\"1.2.840.113549.1.9.4\".digest")
    i = i + 1