Chilkat2-Python

Validate a .pkpass Archive

See more Digital Signatures Examples

Opens a .pkpass archive (which is just a .zip renamed to .pkpass) and validates the contents. The hashes in the manifest are compared with the computed hash values for each individual file. If all computed hash values match, then the signature is verified. Chilkat2-Python

import sys
import chilkat2

success = False

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

crypt = chilkat2.Crypt2()
zip = chilkat2.Zip()

success = zip.OpenZip("qa_data/pkpass/invalid.pkpass")
if (success == False):
    print(zip.LastErrorText)
    sys.exit()

# Get the contents of the manifest.json file, which contains something like this:

# {
#   "icon.png" : "0296b01347b3173e98438a003b0e88986340b2d8",
#   "logo.png" : "25de09e2d3b01ce1fe00c2ca9a90a2be1aaa05cf",
#   "icon@2x.png" : "5afd9585b08c65fdf105a90c8bd643407cba2787",
#   "pass.json" : "145ea5a5db784fff485126c77ecf7a1fc2a88ee7",
#   "strip@2x.png" : "468fa7bc93e6b55342b56fda09bdce7c829d7d46",
#   "strip.png" : "736d01f84cb73d06e8a9932e43076d68f19461ff"
# }

ent = chilkat2.ZipEntry()
success = zip.EntryOf("manifest.json",ent)
if (success == False):
    print(zip.LastErrorText)
    sys.exit()

# Get the exact content of the manifest.json for later signature verification.
bdManifest = chilkat2.BinData()
success = ent.UnzipToBd(bdManifest)

json = chilkat2.JsonObject()
json.EmitCompact = False
json.Load(ent.UnzipToString(0,"utf-8"))
print(json.Emit())

# For each file in the JSON, get the filename and hex hash value.
crypt.EncodingMode = "hexlower"
crypt.HashAlgorithm = "sha1"

someHashesFailed = False

sbHashHex = chilkat2.StringBuilder()
bdFileData = chilkat2.BinData()
numMembers = json.Size
i = 0
while i < numMembers :
    filename = json.NameAt(i)
    sbHashHex.Clear()
    sbHashHex.Append(json.StringAt(i))

    success = zip.EntryOf(filename,ent)
    if (success == False):
        print(zip.LastErrorText)
        sys.exit()

    # Get the data for this file.
    bdFileData.Clear()
    success = ent.UnzipToBd(bdFileData)

    computedHashHex = crypt.HashBdENC(bdFileData)
    if (sbHashHex.ContentsEqual(computedHashHex,False) == False):
        print("Computed hash does not match stored hash for " + filename)
        print("  computed: " + computedHashHex)
        print("  stored:   " + sbHashHex.GetAsString())
        someHashesFailed = True
    else:
        print("hash verified for " + filename + "(" + computedHashHex + ")")

    i = i + 1

if (someHashesFailed == True):
    print("Some hashes failed.")
    sys.exit()

# Let's verify the signature..
# First get the signature.
success = zip.EntryOf("signature",ent)
if (success == False):
    print(zip.LastErrorText)
    sys.exit()

bdSignature = chilkat2.BinData()
success = ent.UnzipToBd(bdSignature)

# Show the contents of the signature in base64 encoding.
print("Signature:")
print(bdSignature.GetEncoded("base64_mime"))
print("----")

# Verify the signature against the manifest.json
crypt.EncodingMode = "base64"
verified = crypt.VerifyBdENC(bdManifest,bdSignature.GetEncoded("base64"))
if (verified == False):
    print(crypt.LastErrorText)

print("signature verified = " + str(verified))