(Swift 2) 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 Downloads for the Swift Programming Language MAC OS X (Cocoa) Objective-C/Swift Libs iOS Objective-C/Swift Libs

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

    let crypt = CkoCrypt2()
    let zip = CkoZip()

    var success: Bool = zip.OpenZip("qa_data/pkpass/invalid.pkpass")
    if success == false {
        print("\(zip.LastErrorText)")
        return
    }

    // 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"
    // }

    var ent: CkoZipEntry? = zip.GetEntryByName("manifest.json")
    if zip.LastMethodSuccess == false {
        print("manifest.json entry not found.")
        return
    }

    // Get the exact content of the manifest.json for later signature verification.
    let bdManifest = CkoBinData()
    success = ent!.UnzipToBd(bdManifest)

    let json = CkoJsonObject()
    json.EmitCompact = false
    json.Load(ent!.UnzipToString(0, srcCharset: "utf-8"))
    print("\(json.Emit())")

    ent = nil

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

    var someHashesFailed: Bool = false
    var filename: String?
    let sbHashHex = CkoStringBuilder()
    let bdFileData = CkoBinData()
    var numMembers: Int = json.Size.intValue
    var i: Int = 0
    while i < numMembers {
        filename = json.NameAt(i)
        sbHashHex.Clear()
        sbHashHex.Append(json.StringAt(i))

        ent = zip.GetEntryByName(filename)
        if zip.LastMethodSuccess == false {
            print("\(filename!) not found in the pkpass file.")
            return
        }

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

        var computedHashHex: String? = crypt.HashBdENC(bdFileData)
        if sbHashHex.ContentsEqual(computedHashHex, caseSensitive: 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!))")
        }

        ent = nil

        i = i + 1
    }

    if someHashesFailed == true {
        print("Some hashes failed.")
        return
    }

    // Let's verify the signature..
    // First get the signature.
    ent = zip.GetEntryByName("signature")
    if zip.LastMethodSuccess == false {
        print("signature not found in the pkpass file.")
        return
    }

    let bdSignature = CkoBinData()
    success = ent!.UnzipToBd(bdSignature)
    ent = nil

    // 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"
    var verified: Bool = crypt.VerifyBdENC(bdManifest, encodedSig: bdSignature.GetEncoded("base64"))
    if verified == false {
        print("\(crypt.LastErrorText)")
    }

    print("signature verified = \(verified)")

}