Add support for Verifiable Health Links (VHL) with strict VHL-only processing

README.md

@@ -179,4 +179,4 @@ Unless required by applicable law or agreed to in writing, software
 distributed under the License is distributed on an "AS IS" BASIS,
 WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 See the License for the specific language governing permissions and
-limitations under the License.
+limitations under the License.

app/src/main/java/org/who/gdhcnvalidator/views/ResultFragment.kt

@@ -1,14 +1,16 @@
 package org.who.gdhcnvalidator.views
 
 import android.annotation.SuppressLint
+import android.app.AlertDialog
+import android.content.Intent
 import android.graphics.PorterDuff
+import android.net.Uri
 import android.os.Bundle
 import android.util.TypedValue
 import android.view.LayoutInflater
 import android.view.View
 import android.view.ViewGroup
-import android.widget.LinearLayout
-import android.widget.TextView
+import android.widget.*
 import androidx.fragment.app.Fragment
 import androidx.navigation.fragment.findNavController
 import androidx.navigation.fragment.navArgs
@@ -21,6 +23,7 @@ import org.who.gdhcnvalidator.R
 import org.who.gdhcnvalidator.databinding.FragmentResultBinding
 import org.who.gdhcnvalidator.services.DDCCFormatter
 import org.who.gdhcnvalidator.trust.TrustRegistry
+import org.who.gdhcnvalidator.verify.hcert.healthlink.VhlVerifier
 import kotlin.time.ExperimentalTime
 import kotlin.time.measureTimedValue
 
@@ -45,6 +48,10 @@ class ResultFragment : Fragment() {
         QRDecoder.Status.REVOKED_KEYS to R.string.verification_status_revoked_keys,
         QRDecoder.Status.INVALID_SIGNATURE to R.string.verification_status_invalid_signature,
         QRDecoder.Status.VERIFIED to R.string.verification_status_verified,
+        // VHL specific statuses (we'll need to add these strings)
+        QRDecoder.Status.VHL_REQUIRES_PIN to R.string.vhl_status_requires_pin,
+        QRDecoder.Status.VHL_INVALID_URI to R.string.vhl_status_invalid_uri,
+        QRDecoder.Status.VHL_FETCH_ERROR to R.string.vhl_status_fetch_error,
     )
 
     override fun onCreateView(
@@ -152,42 +159,51 @@ class ResultFragment : Fragment() {
         if (DDCC.contents != null) {
             binding?.tvResultCard?.visibility = TextView.VISIBLE
 
-            val card = DDCCFormatter().run(DDCC.composition()!!)
-
-            // Credential
-            setTextView(binding?.tvResultScanDate, card.cardTitle, binding?.tvResultScanDate)
-            setTextView(binding?.tvResultValidUntil, card.validUntil, binding?.llResultValidUntil)
-
-            // Patient
-            setTextView(binding?.tvResultName, card.personName, binding?.tvResultName)
-            setTextView(binding?.tvResultPersonDetails, card.personDetails, binding?.tvResultPersonDetails)
-            setTextView(binding?.tvResultIdentifier, card.identifier, binding?.tvResultIdentifier)
-
-            // Location, Practice, Practitioner
-            setTextView(binding?.tvResultHcid, card.hcid, binding?.llResultHcid)
-            setTextView(binding?.tvResultPha, card.pha, binding?.llResultPha)
-            setTextView(binding?.tvResultHw, card.hw, binding?.llResultHw)
-
-            // Test Result
-            setTextView(binding?.tvResultTestType, card.testType, binding?.tvResultTestType)
-            setTextView(binding?.tvResultTestTypeDetail, card.testTypeDetail, binding?.llResultTestTypeDetail)
-            setTextView(binding?.tvResultTestDate, card.testDate, binding?.llResultTestDate)
-            setTextView(binding?.tvResultTestTitle, card.testResult, binding?.tvResultTestTitle)
-
-            // Immunization
-            setTextView(binding?.tvResultVaccineType, card.vaccineType, binding?.tvResultVaccineType)
-            setTextView(binding?.tvResultDoseTitle, card.dose, binding?.tvResultDoseTitle)
-            setTextView(binding?.tvResultDoseDate, card.doseDate, binding?.llResultDoseDate)
-            setTextView(binding?.tvResultVaccineValid, card.vaccineValid, binding?.llResultVaccineValid)
-            setTextView(binding?.tvResultVaccineInfo, card.vaccineInfo, binding?.llResultVaccineInfo)
-            setTextView(binding?.tvResultVaccineInfo2, card.vaccineInfo2, binding?.llResultVaccineInfo2)
-            setTextView(binding?.tvResultCentre, card.location, binding?.llResultCentre)
-
-            // Recommendation
-            setTextView(binding?.tvResultNextDose, card.nextDose, binding?.llResultNextDose)
-
-            // Status
-            binding?.llResultStatus?.removeAllViews()
+            // Check if this is a VHL result with file list
+            if (DDCC.vhlInfo?.fileList != null) {
+                showVhlFileList(DDCC.vhlInfo.fileList)
+            } else {
+                // Traditional health certificate display
+                val card = DDCCFormatter().run(DDCC.composition()!!)
+
+                // Credential
+                setTextView(binding?.tvResultScanDate, card.cardTitle, binding?.tvResultScanDate)
+                setTextView(binding?.tvResultValidUntil, card.validUntil, binding?.llResultValidUntil)
+
+                // Patient
+                setTextView(binding?.tvResultName, card.personName, binding?.tvResultName)
+                setTextView(binding?.tvResultPersonDetails, card.personDetails, binding?.tvResultPersonDetails)
+                setTextView(binding?.tvResultIdentifier, card.identifier, binding?.tvResultIdentifier)
+
+                // Location, Practice, Practitioner
+                setTextView(binding?.tvResultHcid, card.hcid, binding?.llResultHcid)
+                setTextView(binding?.tvResultPha, card.pha, binding?.llResultPha)
+                setTextView(binding?.tvResultHw, card.hw, binding?.llResultHw)
+
+                // Test Result
+                setTextView(binding?.tvResultTestType, card.testType, binding?.tvResultTestType)
+                setTextView(binding?.tvResultTestTypeDetail, card.testTypeDetail, binding?.llResultTestTypeDetail)
+                setTextView(binding?.tvResultTestDate, card.testDate, binding?.llResultTestDate)
+                setTextView(binding?.tvResultTestTitle, card.testResult, binding?.tvResultTestTitle)
+
+                // Immunization
+                setTextView(binding?.tvResultVaccineType, card.vaccineType, binding?.tvResultVaccineType)
+                setTextView(binding?.tvResultDoseTitle, card.dose, binding?.tvResultDoseTitle)
+                setTextView(binding?.tvResultDoseDate, card.doseDate, binding?.llResultDoseDate)
+                setTextView(binding?.tvResultVaccineValid, card.vaccineValid, binding?.llResultVaccineValid)
+                setTextView(binding?.tvResultVaccineInfo, card.vaccineInfo, binding?.llResultVaccineInfo)
+                setTextView(binding?.tvResultVaccineInfo2, card.vaccineInfo2, binding?.llResultVaccineInfo2)
+                setTextView(binding?.tvResultCentre, card.location, binding?.llResultCentre)
+
+                // Recommendation
+                setTextView(binding?.tvResultNextDose, card.nextDose, binding?.llResultNextDose)
+
+                // Status
+                binding?.llResultStatus?.removeAllViews()
+            }
+        } else if (DDCC.status == QRDecoder.Status.VHL_REQUIRES_PIN) {
+            // Show PIN entry interface
+            showVhlPinEntry(DDCC)
         }
     }
 
@@ -281,6 +297,211 @@ class ResultFragment : Fragment() {
             null
         }
     }
+
+    /**
+     * Shows PIN entry dialog for VHL
+     */
+    private fun showVhlPinEntry(vhlResult: QRDecoder.VerificationResult) {
+        val input = EditText(requireContext())
+        input.hint = "Enter PIN"
+        input.inputType = android.text.InputType.TYPE_CLASS_NUMBER or android.text.InputType.TYPE_NUMBER_VARIATION_PASSWORD
+
+        AlertDialog.Builder(requireContext())
+            .setTitle("PIN Required")
+            .setMessage("This Verifiable Health Link requires a PIN to access the manifest.")
+            .setView(input)
+            .setPositiveButton("OK") { _, _ ->
+                val pin = input.text.toString()
+                fetchVhlManifestWithPin(vhlResult, pin)
+            }
+            .setNegativeButton("Cancel") { dialog, _ ->
+                dialog.cancel()
+            }
+            .show()
+    }
+
+    /**
+     * Fetches VHL manifest with PIN and updates the display
+     */
+    private fun fetchVhlManifestWithPin(vhlResult: QRDecoder.VerificationResult, pin: String) {
+        CoroutineScope(Dispatchers.Main + Job()).launch {
+            val decodedLink = vhlResult.vhlInfo?.decodedLink
+            if (decodedLink != null) {
+                withContext(Dispatchers.IO) {
+                    val vhlVerifier = VhlVerifier()
+                    val request = VhlVerifier.VhlManifestRequest(decodedLink.url, pin)
+                    val manifest = vhlVerifier.fetchManifest(request)
+
+                    withContext(Dispatchers.Main) {
+                        if (manifest != null) {
+                            val fileList = vhlVerifier.extractFileList(manifest)
+                            showVhlFileList(fileList)
+                        } else {
+                            Toast.makeText(requireContext(), "Failed to fetch manifest. Check your PIN.", Toast.LENGTH_LONG).show()
+                        }
+                    }
+                }
+            }
+        }
+    }
+
+    /**
+     * Shows the list of files available in the VHL manifest
+     */
+    private fun showVhlFileList(fileList: List<VhlVerifier.VhlFileInfo>) {
+        // Clear existing content and show file list
+        clearResultFields()
+
+        // Get the main content container
+        val resultCard = binding?.root?.findViewById<LinearLayout>(R.id.tv_result_card2)
+        resultCard?.removeAllViews()
+
+        // Add header
+        val header = TextView(requireContext())
+        header.text = "Available Files"
+        header.textSize = 18f
+        header.setTypeface(null, android.graphics.Typeface.BOLD)
+        header.setPadding(0, 0, 0, 16)
+        resultCard?.addView(header)
+
+        // Add each file as a clickable item
+        fileList.forEach { file ->
+            val fileItem = createFileListItem(file)
+            resultCard?.addView(fileItem)
+        }
+
+        binding?.tvResultCard?.visibility = View.VISIBLE
+    }
+
+    /**
+     * Creates a clickable item for each file in the VHL manifest
+     */
+    private fun createFileListItem(file: VhlVerifier.VhlFileInfo): View {
+        val fileItem = LinearLayout(requireContext())
+        fileItem.orientation = LinearLayout.HORIZONTAL
+        fileItem.setPadding(16, 16, 16, 16)
+        fileItem.isClickable = true
+
+        // Add some background styling
+        val typedValue = TypedValue()
+        requireContext().theme.resolveAttribute(android.R.attr.selectableItemBackground, typedValue, true)
+        fileItem.setBackgroundResource(typedValue.resourceId)
+
+        // File icon based on type
+        val icon = ImageView(requireContext())
+        when (file.type) {
+            "PDF" -> icon.setImageResource(android.R.drawable.ic_menu_edit)
+            "FHIR_IPS" -> icon.setImageResource(android.R.drawable.ic_menu_info_details)
+            else -> icon.setImageResource(android.R.drawable.ic_menu_help)
+        }
+        icon.layoutParams = LinearLayout.LayoutParams(64, 64)
+        fileItem.addView(icon)
+
+        // File details
+        val textContainer = LinearLayout(requireContext())
+        textContainer.orientation = LinearLayout.VERTICAL
+        textContainer.layoutParams = LinearLayout.LayoutParams(0, LinearLayout.LayoutParams.WRAP_CONTENT, 1f)
+        textContainer.setPadding(16, 0, 0, 0)
+
+        val title = TextView(requireContext())
+        title.text = file.title
+        title.textSize = 16f
+        title.setTypeface(null, android.graphics.Typeface.BOLD)
+        textContainer.addView(title)
+
+        val subtitle = TextView(requireContext())
+        subtitle.text = "Type: ${file.type}"
+        subtitle.textSize = 14f
+        textContainer.addView(subtitle)
+
+        if (file.size != null) {
+            val size = TextView(requireContext())
+            size.text = "Size: ${file.size} bytes"
+            size.textSize = 12f
+            textContainer.addView(size)
+        }
+
+        fileItem.addView(textContainer)
+
+        // Click handler
+        fileItem.setOnClickListener {
+            handleFileClick(file)
+        }
+
+        // Add some margin between items
+        val layoutParams = LinearLayout.LayoutParams(
+            LinearLayout.LayoutParams.MATCH_PARENT,
+            LinearLayout.LayoutParams.WRAP_CONTENT
+        )
+        layoutParams.setMargins(0, 8, 0, 8)
+        fileItem.layoutParams = layoutParams
+
+        return fileItem
+    }
+
+    /**
+     * Handles clicks on file items
+     */
+    private fun handleFileClick(file: VhlVerifier.VhlFileInfo) {
+        when (file.type) {
+            "PDF" -> {
+                if (file.url != null) {
+                    // Open PDF in browser or external app
+                    val intent = Intent(Intent.ACTION_VIEW, Uri.parse(file.url))
+                    startActivity(intent)
+                } else {
+                    Toast.makeText(requireContext(), "PDF URL not available", Toast.LENGTH_SHORT).show()
+                }
+            }
+            "FHIR_IPS" -> {
+                // Display FHIR IPS content
+                showFhirIpsDialog(file)
+            }
+            else -> {
+                Toast.makeText(requireContext(), "File type not supported: ${file.type}", Toast.LENGTH_SHORT).show()
+            }
+        }
+    }
+
+    /**
+     * Shows FHIR IPS content in a dialog
+     */
+    private fun showFhirIpsDialog(file: VhlVerifier.VhlFileInfo) {
+        AlertDialog.Builder(requireContext())
+            .setTitle(file.title)
+            .setMessage("FHIR IPS Document\n\nThis contains structured health information that would be processed and displayed in a production implementation.")
+            .setPositiveButton("OK") { dialog, _ ->
+                dialog.dismiss()
+            }
+            .show()
+    }
+
+    /**
+     * Clears all result fields for VHL display
+     */
+    private fun clearResultFields() {
+        binding?.tvResultScanDate?.visibility = View.GONE
+        binding?.llResultValidUntil?.visibility = View.GONE
+        binding?.tvResultName?.visibility = View.GONE
+        binding?.tvResultPersonDetails?.visibility = View.GONE
+        binding?.tvResultIdentifier?.visibility = View.GONE
+        binding?.llResultHcid?.visibility = View.GONE
+        binding?.llResultPha?.visibility = View.GONE
+        binding?.llResultHw?.visibility = View.GONE
+        binding?.tvResultTestType?.visibility = View.GONE
+        binding?.llResultTestTypeDetail?.visibility = View.GONE
+        binding?.llResultTestDate?.visibility = View.GONE
+        binding?.tvResultTestTitle?.visibility = View.GONE
+        binding?.tvResultVaccineType?.visibility = View.GONE
+        binding?.tvResultDoseTitle?.visibility = View.GONE
+        binding?.llResultDoseDate?.visibility = View.GONE
+        binding?.llResultVaccineValid?.visibility = View.GONE
+        binding?.llResultVaccineInfo?.visibility = View.GONE
+        binding?.llResultVaccineInfo2?.visibility = View.GONE
+        binding?.llResultCentre?.visibility = View.GONE
+        binding?.llResultNextDose?.visibility = View.GONE
+        binding?.llResultStatus?.visibility = View.GONE
+    }
 
     override fun onDestroyView() {
         super.onDestroyView()

app/src/main/res/values/strings.xml

@@ -51,4 +51,9 @@
     <string name="verification_status_invalid_signature">Invalid Signature</string>
     <string name="verification_status_verified">Signature Verified</string>
     <string name="verification_status_verified_test_scope">Signature Verified (Dev)</string>
+
+    <!-- VHL (Verifiable Health Link) specific strings -->
+    <string name="vhl_status_requires_pin">PIN Required for VHL</string>
+    <string name="vhl_status_invalid_uri">Invalid VHL URI</string>
+    <string name="vhl_status_fetch_error">VHL Manifest Fetch Error</string>
 </resources>

docs/data-models.md

@@ -171,13 +171,32 @@ WHO's international vaccination certificate standard.
 
 **Mapper:** [`DvcMapper`](../verify/src/main/java/org/who/gdhcnvalidator/verify/hcert/icvp/DvcMapper.kt)
 
-### 7. Smart Health Links
+### 7. Smart Health Links and Verifiable Health Links (VHL)
 
 **Source:** [`verify/src/main/java/org/who/gdhcnvalidator/verify/hcert/healthlink/SmartHealthLinkModel.kt`](../verify/src/main/java/org/who/gdhcnvalidator/verify/hcert/healthlink/SmartHealthLinkModel.kt)
 
-Support for Smart Health Links protocol for sharing health data.
+Support for Smart Health Links (SHL) and Verifiable Health Links (VHL) protocol for sharing health data.
 
-**Mapper:** [`HealthLinkMapper`](../verify/src/main/java/org/who/gdhcnvalidator/verify/hcert/healthlink/HealthLinkMapper.kt) (TODO: Implementation pending)
+#### SmartHealthLinkModel
+**Key Fields:**
+- `u: StringType` - URI containing the link to health data manifest
+
+**VHL Features:**
+- Supports both `vhlink:/` and `shlink:/` URI formats
+- Base64 decoding of URI payload to extract manifest URL
+- PIN requirement detection and handling
+- Manifest fetching with optional PIN parameter
+
+#### VHL Processing Flow
+1. **URI Detection**: QR codes starting with `vhlink:/` or `shlink:/` are identified as VHL
+2. **URI Decoding**: Base64 decode the URI payload to extract manifest URL and flags
+3. **PIN Handling**: If PIN is required (P flag), prompt user for PIN entry
+4. **Manifest Fetching**: HTTP request to retrieve FHIR SearchSet Bundle manifest
+5. **File Extraction**: Parse manifest to extract available files (PDF, FHIR IPS)
+6. **User Interface**: Display file list with download/view options
+
+**Mapper:** [`HealthLinkMapper`](../verify/src/main/java/org/who/gdhcnvalidator/verify/hcert/healthlink/HealthLinkMapper.kt)
+**Verifier:** [`VhlVerifier`](../verify/src/main/java/org/who/gdhcnvalidator/verify/hcert/healthlink/VhlVerifier.kt)
 
 ## Data Flow and Transformation