PowerBuilder

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. PowerBuilder

integer li_rc
integer li_Success
oleobject loo_Crypt
oleobject loo_Zip
oleobject loo_Ent
oleobject loo_BdManifest
oleobject loo_Json
integer li_SomeHashesFailed
string ls_Filename
oleobject loo_SbHashHex
oleobject loo_BdFileData
integer li_NumMembers
integer i
string ls_ComputedHashHex
oleobject loo_BdSignature
integer li_Verified

li_Success = 0

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

loo_Crypt = create oleobject
li_rc = loo_Crypt.ConnectToNewObject("Chilkat.Crypt2")
if li_rc < 0 then
    destroy loo_Crypt
    MessageBox("Error","Connecting to COM object failed")
    return
end if
loo_Zip = create oleobject
li_rc = loo_Zip.ConnectToNewObject("Chilkat.Zip")

li_Success = loo_Zip.OpenZip("qa_data/pkpass/invalid.pkpass")
if li_Success = 0 then
    Write-Debug loo_Zip.LastErrorText
    destroy loo_Crypt
    destroy loo_Zip
    return
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"
// }

loo_Ent = create oleobject
li_rc = loo_Ent.ConnectToNewObject("Chilkat.ZipEntry")

li_Success = loo_Zip.EntryOf("manifest.json",loo_Ent)
if li_Success = 0 then
    Write-Debug loo_Zip.LastErrorText
    destroy loo_Crypt
    destroy loo_Zip
    destroy loo_Ent
    return
end if

// Get the exact content of the manifest.json for later signature verification.
loo_BdManifest = create oleobject
li_rc = loo_BdManifest.ConnectToNewObject("Chilkat.BinData")

li_Success = loo_Ent.UnzipToBd(loo_BdManifest)

loo_Json = create oleobject
li_rc = loo_Json.ConnectToNewObject("Chilkat.JsonObject")

loo_Json.EmitCompact = 0
loo_Json.Load(loo_Ent.UnzipToString(0,"utf-8"))
Write-Debug loo_Json.Emit()

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

li_SomeHashesFailed = 0

loo_SbHashHex = create oleobject
li_rc = loo_SbHashHex.ConnectToNewObject("Chilkat.StringBuilder")

loo_BdFileData = create oleobject
li_rc = loo_BdFileData.ConnectToNewObject("Chilkat.BinData")

li_NumMembers = loo_Json.Size
i = 0
do while i < li_NumMembers
    ls_Filename = loo_Json.NameAt(i)
    loo_SbHashHex.Clear()
    loo_SbHashHex.Append(loo_Json.StringAt(i))

    li_Success = loo_Zip.EntryOf(ls_Filename,loo_Ent)
    if li_Success = 0 then
        Write-Debug loo_Zip.LastErrorText
        destroy loo_Crypt
        destroy loo_Zip
        destroy loo_Ent
        destroy loo_BdManifest
        destroy loo_Json
        destroy loo_SbHashHex
        destroy loo_BdFileData
        return
    end if

    // Get the data for this file.
    loo_BdFileData.Clear()
    li_Success = loo_Ent.UnzipToBd(loo_BdFileData)

    ls_ComputedHashHex = loo_Crypt.HashBdENC(loo_BdFileData)
    if loo_SbHashHex.ContentsEqual(ls_ComputedHashHex,0) = 0 then
        Write-Debug "Computed hash does not match stored hash for " + ls_Filename
        Write-Debug "  computed: " + ls_ComputedHashHex
        Write-Debug "  stored:   " + loo_SbHashHex.GetAsString()
        li_SomeHashesFailed = 1
    else
        Write-Debug "hash verified for " + ls_Filename + "(" + ls_ComputedHashHex + ")"
    end if

    i = i + 1
loop

if li_SomeHashesFailed = 1 then
    Write-Debug "Some hashes failed."
    destroy loo_Crypt
    destroy loo_Zip
    destroy loo_Ent
    destroy loo_BdManifest
    destroy loo_Json
    destroy loo_SbHashHex
    destroy loo_BdFileData
    return
end if

// Let's verify the signature..
// First get the signature.
li_Success = loo_Zip.EntryOf("signature",loo_Ent)
if li_Success = 0 then
    Write-Debug loo_Zip.LastErrorText
    destroy loo_Crypt
    destroy loo_Zip
    destroy loo_Ent
    destroy loo_BdManifest
    destroy loo_Json
    destroy loo_SbHashHex
    destroy loo_BdFileData
    return
end if

loo_BdSignature = create oleobject
li_rc = loo_BdSignature.ConnectToNewObject("Chilkat.BinData")

li_Success = loo_Ent.UnzipToBd(loo_BdSignature)

// Show the contents of the signature in base64 encoding.
Write-Debug "Signature:"
Write-Debug loo_BdSignature.GetEncoded("base64_mime")
Write-Debug "----"

// Verify the signature against the manifest.json
loo_Crypt.EncodingMode = "base64"
li_Verified = loo_Crypt.VerifyBdENC(loo_BdManifest,loo_BdSignature.GetEncoded("base64"))
if li_Verified = 0 then
    Write-Debug loo_Crypt.LastErrorText
end if

Write-Debug "signature verified = " + string(li_Verified)


destroy loo_Crypt
destroy loo_Zip
destroy loo_Ent
destroy loo_BdManifest
destroy loo_Json
destroy loo_SbHashHex
destroy loo_BdFileData
destroy loo_BdSignature