(Chilkat2-Python) Verify a .p7m and get Algorithm Information

Demonstrates how to verify a .p7m and then examine the algorithms used by the signature.

Chilkat2 Python Downloads install with pip pip3 install chilkat2 or download... Python Module for Windows, Linux, Alpine Linux, MacOS, Solaris

import sys
import chilkat2

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

crypt = chilkat2.Crypt2()

inFile = "qa_data/p7m/brainpoolP256r1.p7m"
outFile = "qa_output/something.dat"

# Verify and extract the signed data.
success = crypt.VerifyP7M(inFile,outFile)
if (success == False):
    print(crypt.LastErrorText)
    sys.exit()

# Examine details about the signature(s)
# json is a CkJsonObject
json = crypt.LastJsonData()
json.EmitCompact = False
print(json.Emit())

# Sample output

# {
#   "pkcs7": {
#     "verify": {
#       "digestAlgorithms": [
#         "sha256"
#       ],
#       "signerInfo": [
#         {
#           "cert": {
#             "serialNumber": "FFFFE552B302FFFFFF1E34C3ACEB2FFFF",
#             "issuerCN": "The common name of the cert...",
#             "issuerDN": "",
#             "digestAlgOid": "2.16.840.1.101.3.4.2.1",
#             "digestAlgName": "SHA256"
#           },
#           "contentType": "1.2.840.113549.1.7.1",
#           "signingTime": "190409140500Z",
#           "messageDigest": "lQe9If7vZKFf/NlSYu5Esmlw3phVK/RFsbbb1uH73t8=",
#           "signingAlgOid": "1.2.840.10045.4.3.2",
#           "signerDigest": "lQe9If7vZKFf/NlSYu5Esmlw3phVK/RFsbbb1uH73t8=",
#           "authAttr": [
#             {
#               "oid": "1.2.840.113549.1.9.3",
#               "oidName": "contentType"
#             },
#             {
#               "oid": "1.2.840.113549.1.9.5",
#               "oidName": "signingTime"
#             },
#             {
#               "oid": "1.2.840.113549.1.9.52",
#               "oidName": "1.2.840.113549.1.9.52",
#               "der": "MBs ... AwI="
#             },
#             {
#               "oid": "1.2.840.113549.1.9.4",
#               "oidName": "messageDigest"
#             },
#             {
#               "oid": "1.2.840.113549.1.9.16.2.47",
#               "oidName": "signingCertificateV2",
#               "der": "MCYw .. 7PlQ=="
#             },
#             {
#               "oid": "1.2.840.113549.1.9.20",
#               "oidName": "1.2.840.113549.1.9.20"
#             }
#           ]
#         }
#       ]
#     }
#   }
# }

# Code for parsing the above JSON...

i = 0
count_i = json.SizeOfArray("pkcs7.verify.digestAlgorithms")
while i < count_i :
    json.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.I = i
    certSerialNumber = json.StringOf("pkcs7.verify.signerInfo[i].cert.serialNumber")
    certIssuerCN = json.StringOf("pkcs7.verify.signerInfo[i].cert.issuerCN")
    certIssuerDN = json.StringOf("pkcs7.verify.signerInfo[i].cert.issuerDN")
    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")
    signingTime = json.StringOf("pkcs7.verify.signerInfo[i].signingTime")
    messageDigest = json.StringOf("pkcs7.verify.signerInfo[i].messageDigest")
    signingAlgOid = json.StringOf("pkcs7.verify.signerInfo[i].signingAlgOid")
    signerDigest = json.StringOf("pkcs7.verify.signerInfo[i].signerDigest")
    j = 0
    count_j = json.SizeOfArray("pkcs7.verify.signerInfo[i].authAttr")
    while j < count_j :
        json.J = j
        oid = json.StringOf("pkcs7.verify.signerInfo[i].authAttr[j].oid")
        oidName = json.StringOf("pkcs7.verify.signerInfo[i].authAttr[j].oidName")
        der = json.StringOf("pkcs7.verify.signerInfo[i].authAttr[j].der")
        j = j + 1

    i = i + 1

print("Success!")