VBScript

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. VBScript

Dim fso, outFile
Set fso = CreateObject("Scripting.FileSystemObject")
'Create a Unicode (utf-16) output text file.
Set outFile = fso.CreateTextFile("output.txt", True, True)

success = 0

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

set crypt = CreateObject("Chilkat.Crypt2")
set zip = CreateObject("Chilkat.Zip")

success = zip.OpenZip("qa_data/pkpass/invalid.pkpass")
If (success = 0) Then
    outFile.WriteLine(zip.LastErrorText)
    WScript.Quit
End If

' 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"
' }

set ent = CreateObject("Chilkat.ZipEntry")
success = zip.EntryOf("manifest.json",ent)
If (success = 0) Then
    outFile.WriteLine(zip.LastErrorText)
    WScript.Quit
End If

' Get the exact content of the manifest.json for later signature verification.
set bdManifest = CreateObject("Chilkat.BinData")
success = ent.UnzipToBd(bdManifest)

set json = CreateObject("Chilkat.JsonObject")
json.EmitCompact = 0
success = json.Load(ent.UnzipToString(0,"utf-8"))
outFile.WriteLine(json.Emit())

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

someHashesFailed = 0

set sbHashHex = CreateObject("Chilkat.StringBuilder")
set bdFileData = CreateObject("Chilkat.BinData")
numMembers = json.Size
i = 0
Do While i < numMembers
    filename = json.NameAt(i)
    sbHashHex.Clear 
    success = sbHashHex.Append(json.StringAt(i))

    success = zip.EntryOf(filename,ent)
    If (success = 0) Then
        outFile.WriteLine(zip.LastErrorText)
        WScript.Quit
    End If

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

    computedHashHex = crypt.HashBdENC(bdFileData)
    If (sbHashHex.ContentsEqual(computedHashHex,0) = 0) Then
        outFile.WriteLine("Computed hash does not match stored hash for " & filename)
        outFile.WriteLine("  computed: " & computedHashHex)
        outFile.WriteLine("  stored:   " & sbHashHex.GetAsString())
        someHashesFailed = 1
    Else
        outFile.WriteLine("hash verified for " & filename & "(" & computedHashHex & ")")
    End If

    i = i + 1
Loop

If (someHashesFailed = 1) Then
    outFile.WriteLine("Some hashes failed.")
    WScript.Quit
End If

' Let's verify the signature..
' First get the signature.
success = zip.EntryOf("signature",ent)
If (success = 0) Then
    outFile.WriteLine(zip.LastErrorText)
    WScript.Quit
End If

set bdSignature = CreateObject("Chilkat.BinData")
success = ent.UnzipToBd(bdSignature)

' Show the contents of the signature in base64 encoding.
outFile.WriteLine("Signature:")
outFile.WriteLine(bdSignature.GetEncoded("base64_mime"))
outFile.WriteLine("----")

' Verify the signature against the manifest.json
crypt.EncodingMode = "base64"
verified = crypt.VerifyBdENC(bdManifest,bdSignature.GetEncoded("base64"))
If (verified = 0) Then
    outFile.WriteLine(crypt.LastErrorText)
End If

outFile.WriteLine("signature verified = " & verified)

outFile.Close