(Classic ASP) Validate a .pkpass Archive

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.

Chilkat ActiveX Downloads

ActiveX for 32-bit and 64-bit Windows

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

set crypt = Server.CreateObject("Chilkat_9_5_0.Crypt2")
set zip = Server.CreateObject("Chilkat_9_5_0.Zip")

success = zip.OpenZip("qa_data/pkpass/invalid.pkpass")
If (success = 0) Then
    Response.Write "<pre>" & Server.HTMLEncode( zip.LastErrorText) & "</pre>"
    Response.End
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"
' }

' ent is a Chilkat_9_5_0.ZipEntry
Set ent = zip.GetEntryByName("manifest.json")
If (zip.LastMethodSuccess = 0) Then
    Response.Write "<pre>" & Server.HTMLEncode( "manifest.json entry not found.") & "</pre>"
    Response.End
End If

' Get the exact content of the manifest.json for later signature verification.
set bdManifest = Server.CreateObject("Chilkat_9_5_0.BinData")
success = ent.UnzipToBd(bdManifest)

set json = Server.CreateObject("Chilkat_9_5_0.JsonObject")
json.EmitCompact = 0
success = json.Load(ent.UnzipToString(0,"utf-8"))
Response.Write "<pre>" & Server.HTMLEncode( json.Emit()) & "</pre>"

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

someHashesFailed = 0

set sbHashHex = Server.CreateObject("Chilkat_9_5_0.StringBuilder")
set bdFileData = Server.CreateObject("Chilkat_9_5_0.BinData")
numMembers = json.Size
i = 0
Do While i < numMembers
    filename = json.NameAt(i)
    sbHashHex.Clear 
    success = sbHashHex.Append(json.StringAt(i))

    ' ent is a Chilkat_9_5_0.ZipEntry
    Set ent = zip.GetEntryByName(filename)
    If (zip.LastMethodSuccess = 0) Then
        Response.Write "<pre>" & Server.HTMLEncode( filename & " not found in the pkpass file.") & "</pre>"
        Response.End
    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
        Response.Write "<pre>" & Server.HTMLEncode( "Computed hash does not match stored hash for " & filename) & "</pre>"
        Response.Write "<pre>" & Server.HTMLEncode( "  computed: " & computedHashHex) & "</pre>"
        Response.Write "<pre>" & Server.HTMLEncode( "  stored:   " & sbHashHex.GetAsString()) & "</pre>"
        someHashesFailed = 1
    Else
        Response.Write "<pre>" & Server.HTMLEncode( "hash verified for " & filename & "(" & computedHashHex & ")") & "</pre>"
    End If

    i = i + 1
Loop

If (someHashesFailed = 1) Then
    Response.Write "<pre>" & Server.HTMLEncode( "Some hashes failed.") & "</pre>"
    Response.End
End If

' Let's verify the signature..
' First get the signature.
' ent is a Chilkat_9_5_0.ZipEntry
Set ent = zip.GetEntryByName("signature")
If (zip.LastMethodSuccess = 0) Then
    Response.Write "<pre>" & Server.HTMLEncode( "signature not found in the pkpass file.") & "</pre>"
    Response.End
End If

set bdSignature = Server.CreateObject("Chilkat_9_5_0.BinData")
success = ent.UnzipToBd(bdSignature)

' Show the contents of the signature in base64 encoding.
Response.Write "<pre>" & Server.HTMLEncode( "Signature:") & "</pre>"
Response.Write "<pre>" & Server.HTMLEncode( bdSignature.GetEncoded("base64_mime")) & "</pre>"
Response.Write "<pre>" & Server.HTMLEncode( "----") & "</pre>"

' Verify the signature against the manifest.json
crypt.EncodingMode = "base64"
verified = crypt.VerifyBdENC(bdManifest,bdSignature.GetEncoded("base64"))
If (verified = 0) Then
    Response.Write "<pre>" & Server.HTMLEncode( crypt.LastErrorText) & "</pre>"
End If

Response.Write "<pre>" & Server.HTMLEncode( "signature verified = " & verified) & "</pre>"

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