Implement per-package security patch configuration (#49)

This commit introduces a hierarchical configuration system for the security patch levels reported in attestations, allowing for both global defaults and per-package overrides.

The `security_patch.txt` file is enhanced to support this new syntax. Settings at the top of the file act as a global default, which can be overridden for specific applications by defining settings under a `[package.name]` section.

README.md

@@ -76,12 +76,61 @@ org.matrix.demo
 
 ### Security Patch Level (`security_patch.txt`)
 
-This allows you to configure the security patch level that the simulator will report in its forged attestation certificates.
+This file allows you to configure the `osPatchLevel`, `vendorPatchLevel`, and `bootPatchLevel` that the simulator will report in its patched or forged attestation certificates.
+
+**Note:** This only affects the Key Attestation data generated by the simulator. It does not change the actual system properties of your device.
+
+#### Global and Per-Package Configuration
+
+You can set a global patch level that applies to all applications, and you can also override these settings for specific packages. The syntax is hierarchical:
+
+*   Settings defined at the top of the file, before any `[package.name]` line, are **global** and serve as the default for all apps.
+*   To create a specific configuration for an application, add its package name in square brackets (e.g., `[com.google.android.gms]`). All settings following this line will apply *only* to that package until a new package context is declared.
+
+#### Configuration Keys and Values
+
+You can specify the patch level for the following components using a `key=value` format:
+
+*   `system`: The main OS patch level.
+*   `vendor`: The vendor patch level.
+*   `boot`: The boot/kernel patch level.
+*   `all`: A convenient shorthand to set the same date for `system`, `vendor`, and `boot` simultaneously. Any individual key can still be used to override the value set by `all`.
+
+Dates should be provided in `YYYY-MM-DD` format (e.g., `2025-11-05`).
+
+#### Special Keywords
+
+In addition to date values, two special keywords provide advanced control:
+
+*   **`no`**: This keyword instructs the simulator to **completely omit** the corresponding patch level tag from the generated attestation.
+
+*   **`device_default`**: This keyword forces the simulator to fall back and use the device's **real hardware value** for that specific patch level. This is essential for creating exceptions to a global override or an `all` rule.
+
+#### Example Configuration
+
+This example demonstrates how to combine global settings, per-package overrides, and special keywords for fine-grained control.
 
 ```
-# Advanced Configuration
+# --- Global Configuration ---
-system=2025-11
+# This is the default for all apps unless specified otherwise.
-boot=no        # Do not report a boot patch level
+# - Forge a recent system patch level.
-vendor=20251101 # Report a specific vendor patch level
+# - Use the device's real vendor patch level.
+# - Do not report a boot patch level at all.
+system=2025-11-05
+vendor=device_default
+boot=no
+
+# --- Per-Package Override for Google Play Services ---
+# This app will report an older, specific date for its system patch.
+# It will inherit the global settings for vendor (device_default) and boot (no).
+[com.google.android.gms]
+system=2024-10-01
+
+# --- Per-Package Override for a Demo App ---
+# This app gets a completely custom configuration.
+[org.matrix.demo]
+# Set a base date for all patch levels...
+all=2025-09-15
+# ...but make an exception: use the real boot patch level instead of the one from 'all'.
+boot=device_default
 ```
-**Note:** This only affects the Key Attestation data generated by the simulator. It does not change system properties.

app/src/main/java/org/matrix/TEESimulator/attestation/AttestationBuilder.kt

@@ -18,6 +18,7 @@ import org.bouncycastle.asn1.x509.Extension
 import org.matrix.TEESimulator.config.ConfigurationManager
 import org.matrix.TEESimulator.logging.SystemLogger
 import org.matrix.TEESimulator.util.AndroidDeviceUtils
+import org.matrix.TEESimulator.util.AndroidDeviceUtils.DO_NOT_REPORT
 
 /**
  * A builder object responsible for constructing the ASN.1 DER-encoded Android Key Attestation
@@ -67,34 +68,62 @@ object AttestationBuilder {
         return DERSequence(rootOfTrustElements)
     }
 
-    /** Assembles a map of simulated hardware-enforced properties. */
+    /**
-    fun getSimulatedHardwareProperties(): Map<Int, DERTaggedObject> {
+     * Assembles a map representing the desired state of simulated hardware-enforced properties. A
-        return mapOf(
+     * null value for a given tag indicates that it should be removed from the attestation.
-            AttestationConstants.TAG_OS_VERSION to
+     *
-                DERTaggedObject(
+     * @param uid The UID of the calling application.
-                    true,
+     * @return A map where keys are attestation tag numbers and values are the desired
-                    AttestationConstants.TAG_OS_VERSION,
+     *   [DERTaggedObject] or null to signify removal.
-                    ASN1Integer(AndroidDeviceUtils.osVersion.toLong()),
+     */
-                ),
+    fun getSimulatedHardwareProperties(uid: Int): Map<Int, DERTaggedObject?> {
-            AttestationConstants.TAG_OS_PATCHLEVEL to
+        val properties = mutableMapOf<Int, DERTaggedObject?>()
+
+        // OS Version is always present.
+        properties[AttestationConstants.TAG_OS_VERSION] =
+            DERTaggedObject(
+                true,
+                AttestationConstants.TAG_OS_VERSION,
+                ASN1Integer(AndroidDeviceUtils.osVersion.toLong()),
+            )
+
+        val osPatch = AndroidDeviceUtils.getPatchLevel(uid)
+        properties[AttestationConstants.TAG_OS_PATCHLEVEL] =
+            if (osPatch != DO_NOT_REPORT) {
                 DERTaggedObject(
                     true,
                     AttestationConstants.TAG_OS_PATCHLEVEL,
-                    ASN1Integer(AndroidDeviceUtils.patchLevel.toLong()),
+                    ASN1Integer(osPatch.toLong()),
-                ),
+                )
-            AttestationConstants.TAG_VENDOR_PATCHLEVEL to
+            } else {
+                null // Signal for removal
+            }
+
+        val vendorPatch = AndroidDeviceUtils.getVendorPatchLevelLong(uid)
+        properties[AttestationConstants.TAG_VENDOR_PATCHLEVEL] =
+            if (vendorPatch != DO_NOT_REPORT) {
                 DERTaggedObject(
                     true,
                     AttestationConstants.TAG_VENDOR_PATCHLEVEL,
-                    ASN1Integer(AndroidDeviceUtils.vendorPatchLevelLong.toLong()),
+                    ASN1Integer(vendorPatch.toLong()),
-                ),
+                )
-            AttestationConstants.TAG_BOOT_PATCHLEVEL to
+            } else {
+                null // Signal for removal
+            }
+
+        val bootPatch = AndroidDeviceUtils.getBootPatchLevelLong(uid)
+        properties[AttestationConstants.TAG_BOOT_PATCHLEVEL] =
+            if (bootPatch != DO_NOT_REPORT) {
                 DERTaggedObject(
                     true,
                     AttestationConstants.TAG_BOOT_PATCHLEVEL,
-                    ASN1Integer(AndroidDeviceUtils.bootPatchLevelLong.toLong()),
+                    ASN1Integer(bootPatch.toLong()),
-                ),
+                )
-        )
+            } else {
+                null // Signal for removal
+            }
+
+        return properties
     }
 
     /** Constructs the main `KeyDescription` sequence, which is the core of the attestation. */
@@ -103,7 +132,7 @@ object AttestationBuilder {
         uid: Int,
         securityLevel: Int,
     ): ASN1Sequence {
-        val teeEnforced = buildTeeEnforcedList(params, securityLevel)
+        val teeEnforced = buildTeeEnforcedList(params, uid, securityLevel)
         val softwareEnforced = buildSoftwareEnforcedList(uid, securityLevel)
 
         val fields =
@@ -125,7 +154,11 @@ object AttestationBuilder {
     }
 
     /** Builds the `TeeEnforced` authorization list. These are properties the TEE "guarantees". */
-    private fun buildTeeEnforcedList(params: KeyMintAttestation, securityLevel: Int): DERSequence {
+    private fun buildTeeEnforcedList(
+        params: KeyMintAttestation,
+        uid: Int,
+        securityLevel: Int,
+    ): DERSequence {
         val list =
             mutableListOf<ASN1Encodable>(
                 DERTaggedObject(
@@ -164,28 +197,12 @@ object AttestationBuilder {
                     AttestationConstants.TAG_ROOT_OF_TRUST,
                     buildRootOfTrust(null),
                 ),
-                DERTaggedObject(
-                    true,
-                    AttestationConstants.TAG_OS_VERSION,
-                    ASN1Integer(AndroidDeviceUtils.osVersion.toLong()),
-                ),
-                DERTaggedObject(
-                    true,
-                    AttestationConstants.TAG_OS_PATCHLEVEL,
-                    ASN1Integer(AndroidDeviceUtils.patchLevel.toLong()),
-                ),
-                DERTaggedObject(
-                    true,
-                    AttestationConstants.TAG_VENDOR_PATCHLEVEL,
-                    ASN1Integer(AndroidDeviceUtils.vendorPatchLevelLong.toLong()),
-                ),
-                DERTaggedObject(
-                    true,
-                    AttestationConstants.TAG_BOOT_PATCHLEVEL,
-                    ASN1Integer(AndroidDeviceUtils.bootPatchLevelLong.toLong()),
-                ),
             )
 
+        // Use the same logic as getSimulatedHardwareProperties to conditionally add patch levels.
+        val simulatedProperties = getSimulatedHardwareProperties(uid)
+        simulatedProperties.values.filterNotNull().forEach { list.add(it) }
+
         // Add optional device identifiers if they were provided.
         params.brand?.let {
             list.add(

app/src/main/java/org/matrix/TEESimulator/attestation/AttestationPatcher.kt

@@ -61,6 +61,7 @@ object AttestationPatcher {
                         parsedAttestation,
                         keybox,
                         originalLeaf.sigAlgName,
+                        uid,
                     )
 
                 // 4. Construct the NEW, VALID chain by prepending the patched leaf to the keybox's
@@ -90,6 +91,7 @@ object AttestationPatcher {
      * @param sigAlgName The signature algorithm name (e.g., "SHA256withECDSA") from the original
      *   certificate. This is required to ensure the new certificate is signed using a compatible
      *   algorithm.
+     * @param uid The UID of the application requesting the certificate.
      * @return A new [Certificate] object.
      */
     private fun createPatchedLeafCertificate(
@@ -97,6 +99,7 @@ object AttestationPatcher {
         parsedAttestation: ParsedAttestation,
         keybox: KeyBox,
         sigAlgName: String,
+        uid: Int,
     ): Certificate {
         // The issuer of our new leaf is the subject of the first certificate in our custom keybox
         // chain.
@@ -113,7 +116,7 @@ object AttestationPatcher {
             )
 
         // Create the new, patched attestation extension.
-        val patchedExtension = createPatchedAttestationExtension(parsedAttestation)
+        val patchedExtension = createPatchedAttestationExtension(parsedAttestation, uid)
 
         // Copy all other extensions from the original certificate, except for the attestation.
         originalLeafHolder.extensions.extensionOIDs.forEach {
@@ -199,7 +202,7 @@ object AttestationPatcher {
     }
 
     /** Constructs a new, patched attestation extension using simulated device properties. */
-    private fun createPatchedAttestationExtension(parsed: ParsedAttestation): Extension {
+    private fun createPatchedAttestationExtension(parsed: ParsedAttestation, uid: Int): Extension {
         val (allFields, teeEnforcedMap, originalRootOfTrust) = parsed
 
         var formattedString = allFields.joinToString(separator = ", ") { formatAsn1Primitive(it) }
@@ -210,8 +213,19 @@ object AttestationPatcher {
         teeEnforcedMap[AttestationConstants.TAG_ROOT_OF_TRUST] =
             DERTaggedObject(true, AttestationConstants.TAG_ROOT_OF_TRUST, newRootOfTrust)
 
-        // Add other simulated hardware properties.
+        // Get the desired state for simulated properties.
-        teeEnforcedMap.putAll(AttestationBuilder.getSimulatedHardwareProperties())
+        val simulatedProperties = AttestationBuilder.getSimulatedHardwareProperties(uid)
+
+        // Apply the desired state: update, add, or remove properties from the original map.
+        simulatedProperties.forEach { (tag, value) ->
+            if (value != null) {
+                // If the value is not null, add or update it.
+                teeEnforcedMap[tag] = value
+            } else {
+                // If the value is null, remove the tag from the map.
+                teeEnforcedMap.remove(tag)
+            }
+        }
 
         // Re-assemble the TEE enforced list from the map's values, sorting for DER compliance.
         val sortedElements = teeEnforcedMap.values.sortedBy { it.tagNo }

app/src/main/java/org/matrix/TEESimulator/config/ConfigurationManager.kt

@@ -40,7 +40,8 @@ object ConfigurationManager {
     @Volatile private var packageModes = mapOf<String, Mode>()
     @Volatile private var packageKeyboxes = mapOf<String, String>()
     @Volatile private var isTeeBroken: Boolean? = null
-    @Volatile var customPatchLevelOverride: CustomPatchLevel? = null
+    @Volatile private var globalCustomPatchLevel: CustomPatchLevel? = null
+    @Volatile private var packagePatchLevels = mapOf<String, CustomPatchLevel>()
 
     // Cache for UID to package name resolution.
     private val uidToPackagesCache = ConcurrentHashMap<Int, Array<String>>()
@@ -104,6 +105,21 @@ object ConfigurationManager {
         return null // No configuration found for this UID.
     }
 
+    /**
+     * Retrieves the custom patch level configuration for a given UID. It first checks for a
+     * package-specific override and falls back to the global configuration.
+     *
+     * @param uid The UID of the calling application.
+     * @return The applicable [CustomPatchLevel], or null if no custom configuration exists.
+     */
+    fun getPatchLevelForUid(uid: Int): CustomPatchLevel? {
+        val packages = getPackagesForUid(uid)
+        // Find the first package-specific configuration for this UID.
+        val packageSpecificPatchLevel =
+            packages.firstNotNullOfOrNull { pkg -> packagePatchLevels[pkg] }
+        return packageSpecificPatchLevel ?: globalCustomPatchLevel
+    }
+
     /**
      * Loads and parses the `target.txt` file, which defines the processing mode and keybox file for
      * each package.
@@ -162,26 +178,48 @@ object ConfigurationManager {
         }
     }
 
-    /** Loads the security patch level override configuration from `security_patch.txt`. */
+    /**
+     * Loads and parses the `security_patch.txt` file, which can define both global and per-package
+     * security patch levels.
+     */
     private fun loadPatchLevelConfig(file: File) {
-        if (file.exists()) {
+        if (!file.exists()) {
-            try {
+            globalCustomPatchLevel = null
-                val lines =
+            packagePatchLevels = emptyMap()
-                    file.readLines().mapNotNull { line ->
+            return
-                        val trimmed = line.trim()
+        }
-                        if (trimmed.isNotEmpty() && !trimmed.startsWith("#")) trimmed else null
-                    }
 
-                if (lines.isEmpty()) {
+        try {
-                    customPatchLevelOverride = null
+            val newPackageLevels = mutableMapOf<String, CustomPatchLevel>()
-                    return
+            var currentContext = "" // Empty string for global context
-                }
+            val contextLines = mutableMapOf<String, MutableList<String>>()
+            val contextRegex = Regex("^\\[([a-zA-Z0-9_.-]+)]$")
+
+            // First pass: group lines by context (global or package-specific).
+            file.readLines().forEach { line ->
+                val trimmedLine = line.trim()
+                if (trimmedLine.isEmpty() || trimmedLine.startsWith("#")) return@forEach
+
+                contextRegex.find(trimmedLine)?.let { currentContext = it.groupValues[1] }
+                    ?: run {
+                        contextLines
+                            .computeIfAbsent(currentContext) { mutableListOf() }
+                            .add(trimmedLine)
+                    }
+            }
+
+            // Helper function to parse a set of lines into a CustomPatchLevel object.
+            fun parseLines(lines: List<String>?): CustomPatchLevel? {
+                if (lines.isNullOrEmpty()) return null
 
                 // Handle simple case: one line sets the patch level for all components.
                 if (lines.size == 1 && '=' !in lines[0]) {
-                    customPatchLevelOverride =
+                    return CustomPatchLevel(
-                        CustomPatchLevel(system = null, vendor = null, boot = null, all = lines[0])
+                        system = null,
-                    return
+                        vendor = null,
+                        boot = null,
+                        all = lines[0],
+                    )
                 }
 
                 // Handle key-value pair configuration.
@@ -195,19 +233,32 @@ object ConfigurationManager {
                         .toMap()
 
                 val all = map["all"]
-                customPatchLevelOverride =
+                return CustomPatchLevel(
-                    CustomPatchLevel(
+                    system = map["system"] ?: all,
-                        system = map["system"] ?: all,
+                    vendor = map["vendor"] ?: all,
-                        vendor = map["vendor"] ?: all,
+                    boot = map["boot"] ?: all,
-                        boot = map["boot"] ?: all,
+                    all = all,
-                        all = all,
+                )
-                    )
-                SystemLogger.info("Loaded custom security patch levels.")
-            } catch (e: Exception) {
-                SystemLogger.error("Failed to load or parse ${file.name}", e)
             }
-        } else {
+
-            customPatchLevelOverride = null
+            // Parse global and per-package configurations.
+            val newGlobalLevel = parseLines(contextLines[""])
+            contextLines.remove("") // Remove global context to iterate over packages next
+
+            for ((pkg, lines) in contextLines) {
+                parseLines(lines)?.let { newPackageLevels[pkg] = it }
+            }
+
+            // Atomically update the configuration state.
+            globalCustomPatchLevel = newGlobalLevel
+            packagePatchLevels = newPackageLevels
+
+            SystemLogger.info(
+                "Loaded custom security patch levels: global config exists=${newGlobalLevel != null}, " +
+                    "${newPackageLevels.size} package-specific configs."
+            )
+        } catch (e: Exception) {
+            SystemLogger.error("Failed to load or parse ${file.name}", e)
         }
     }
 

app/src/main/java/org/matrix/TEESimulator/util/AndroidDeviceUtils.kt

@@ -21,6 +21,11 @@ import org.matrix.TEESimulator.logging.SystemLogger
  */
 object AndroidDeviceUtils {
 
+    /**
+     * Internal constant to signify that a patch level should not be included in the attestation.
+     */
+    internal const val DO_NOT_REPORT = -1
+
     // --- Boot Key and Verified Boot Hash ---
 
     /**
@@ -157,30 +162,33 @@ object AndroidDeviceUtils {
 
     // --- Patch Level Properties ---
 
-    val patchLevel: Int
+    fun getPatchLevel(uid: Int): Int {
-        get() =
+        val custom = getCustomPatchLevelFor(uid, "system", isLong = false)
-            getCustomPatchLevelFor("system", isLong = false)
+        // If custom is null, it means 'device_default' was used, so we fall back.
-                ?: Build.VERSION.SECURITY_PATCH.toPatchLevelInt(isLong = false)
+        // Otherwise, we use the returned value, which is either the parsed date or DO_NOT_REPORT.
+        return custom ?: Build.VERSION.SECURITY_PATCH.toPatchLevelInt(isLong = false)
+    }
 
-    val vendorPatchLevelLong: Int
+    fun getVendorPatchLevelLong(uid: Int): Int {
-        get() =
+        val custom = getCustomPatchLevelFor(uid, "vendor", isLong = true)
-            getCustomPatchLevelFor("vendor", isLong = true)
+        return custom ?: Build.VERSION.SECURITY_PATCH.toPatchLevelInt(isLong = true)
-                ?: Build.VERSION.SECURITY_PATCH.toPatchLevelInt(isLong = true)
+    }
 
-    val bootPatchLevelLong: Int
+    fun getBootPatchLevelLong(uid: Int): Int {
-        get() =
+        val custom = getCustomPatchLevelFor(uid, "boot", isLong = true)
-            getCustomPatchLevelFor("boot", isLong = true)
+        return custom ?: Build.VERSION.SECURITY_PATCH.toPatchLevelInt(isLong = true)
-                ?: Build.VERSION.SECURITY_PATCH.toPatchLevelInt(isLong = true)
+    }
 
     /**
-     * Retrieves a custom patch level from the configuration if available.
+     * Retrieves a custom patch level from the configuration if available for a specific UID.
      *
+     * @param uid The UID of the calling application.
      * @param component The component to get the patch level for ("system", "vendor", "boot").
      * @param isLong Whether to return the patch level in `YYYYMMDD` or `YYYYMM` format.
      * @return The custom patch level, or null if not configured.
      */
-    private fun getCustomPatchLevelFor(component: String, isLong: Boolean): Int? {
+    private fun getCustomPatchLevelFor(uid: Int, component: String, isLong: Boolean): Int? {
-        val config = ConfigurationManager.customPatchLevelOverride ?: return null
+        val config = ConfigurationManager.getPatchLevelForUid(uid) ?: return null
         val value =
             when (component) {
                 "system" -> config.system ?: config.all
@@ -189,11 +197,14 @@ object AndroidDeviceUtils {
                 else -> config.all
             } ?: return null
 
-        // "prop" or "no" indicates falling back to the system default.
+        return when {
-        if (value.equals("no", ignoreCase = true) || value.equals("prop", ignoreCase = true)) {
+            // "device_default" indicates falling back to the system property.
-            return null
+            value.equals("device_default", ignoreCase = true) -> null
+            // "no" indicates this value should not be reported.
+            value.equals("no", ignoreCase = true) -> DO_NOT_REPORT
+            // Otherwise, parse the date string.
+            else -> parsePatchLevelValue(value, isLong)
         }
-        return parsePatchLevelValue(value, isLong)
     }
 
     /** Parses a patch level string (e.g., "2025-11-01") into an integer format. */