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fenix/app/src/main/java/org/mozilla/fenix/components/metrics/ActivationPing.kt

188 lines
7.4 KiB
Kotlin

/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
package org.mozilla.fenix.components.metrics
import android.content.Context
import android.content.SharedPreferences
import android.util.Base64
import androidx.annotation.VisibleForTesting
import mozilla.components.support.base.log.logger.Logger
import org.mozilla.fenix.GleanMetrics.Activation
import org.mozilla.fenix.GleanMetrics.Pings
import com.google.android.gms.ads.identifier.AdvertisingIdClient
import com.google.android.gms.common.GooglePlayServicesNotAvailableException
import com.google.android.gms.common.GooglePlayServicesRepairableException
import kotlinx.coroutines.CoroutineScope
import kotlinx.coroutines.Dispatchers
import kotlinx.coroutines.withContext
import kotlinx.coroutines.launch
import java.io.IOException
import java.security.NoSuchAlgorithmException
import java.security.spec.InvalidKeySpecException
import javax.crypto.SecretKeyFactory
import javax.crypto.spec.PBEKeySpec
class ActivationPing(private val context: Context) {
companion object {
// The number of iterations to compute the hash. RFC 2898 suggests
// a minimum of 1000 iterations.
const val PBKDF2_ITERATIONS = 1000
const val PBKDF2_KEY_LEN_BITS = 256
}
private val prefs: SharedPreferences by lazy {
context.getSharedPreferences(
"${this.javaClass.canonicalName}.prefs", Context.MODE_PRIVATE)
}
/**
* Checks whether or not the activation ping was already
* triggered by the application.
*
* Note that this only tells us that Fenix triggered the
* ping and then delegated the transmission to Glean. We
* have no way to tell if it was actually sent or not.
*
* @return true if it was already triggered, false otherwise.
*/
@VisibleForTesting(otherwise = VisibleForTesting.PRIVATE)
internal fun wasAlreadyTriggered(): Boolean {
return prefs.getBoolean("ping_sent", false)
}
/**
* Marks the "activation" ping as triggered by the application.
* This ensures the ping is not triggered again at the next app
* start.
*/
@VisibleForTesting(otherwise = VisibleForTesting.PRIVATE)
internal fun markAsTriggered() {
prefs.edit().putBoolean("ping_sent", true).apply()
}
/**
* Query the Google Advertising API to get the Google Advertising ID.
*
* This is meant to be used off the main thread. The API will throw an
* exception and we will print a log message otherwise.
*
* @return a String containing the Google Advertising ID or null.
*/
@Suppress("TooGenericExceptionCaught")
@VisibleForTesting(otherwise = VisibleForTesting.PRIVATE)
internal fun getAdvertisingID(): String? {
return try {
AdvertisingIdClient.getAdvertisingIdInfo(context).id
} catch (e: GooglePlayServicesNotAvailableException) {
Logger.debug("ActivationPing - Google Play not installed on the device")
null
} catch (e: GooglePlayServicesRepairableException) {
Logger.debug("ActivationPing - recoverable error connecting to Google Play Services")
null
} catch (e: IllegalStateException) {
// This is unlikely to happen, as this should be running off the main thread.
Logger.debug("ActivationPing - AdvertisingIdClient must be called off the main thread")
null
} catch (e: IOException) {
Logger.debug("ActivationPing - unable to connect to Google Play Services")
null
} catch (e: NullPointerException) {
Logger.debug("ActivationPing - no Google Advertising ID available")
null
}
}
/**
* Get the salt to use for hashing. This is a convenience
* function to help with unit tests.
*/
@VisibleForTesting(otherwise = VisibleForTesting.PRIVATE)
internal fun getHashingSalt(): String = "org.mozilla.fenix-salt"
/**
* Produces an hashed version of the Google Advertising ID.
* We want users using more than one of our products to report a different
* ID in each of them. This function runs off the main thread and is CPU-bound.
*
* @return an hashed and salted Google Advertising ID or null if it was not possible
* to get the Google Advertising ID.
*/
@VisibleForTesting(otherwise = VisibleForTesting.PRIVATE)
internal suspend fun getHashedIdentifier(): String? = withContext(Dispatchers.Default) {
getAdvertisingID()?.let { unhashedID ->
// Add some salt to the ID, before hashing. For this specific use-case, it's ok
// to use the same salt value for all the hashes. We want hashes to be stable
// within a single product, but we don't want hashes to be the same across different
// products (e.g. Fennec vs Fenix).
val salt = getHashingSalt()
// Apply hashing.
try {
// Note that we intentionally want to use slow hashing functions here in order
// to increase the cost of potentially repeatedly guess the original unhashed
// identifier.
val keySpec = PBEKeySpec(
unhashedID.toCharArray(),
salt.toByteArray(),
PBKDF2_ITERATIONS,
PBKDF2_KEY_LEN_BITS)
val keyFactory = SecretKeyFactory.getInstance("PBKDF2WithHmacSHA1")
val hashedBytes = keyFactory.generateSecret(keySpec).encoded
Base64.encodeToString(hashedBytes, Base64.NO_WRAP)
} catch (e: java.lang.NullPointerException) {
Logger.error("ActivationPing - missing or wrong salt parameter")
null
} catch (e: IllegalArgumentException) {
Logger.error("ActivationPing - wrong parameter", e)
null
} catch (e: NoSuchAlgorithmException) {
Logger.error("ActivationPing - algorithm not available")
null
} catch (e: InvalidKeySpecException) {
Logger.error("ActivationPing - invalid key spec")
null
}
}
}
/**
* Fills the metrics and triggers the 'activation' ping.
* This is a separate function to simplify unit-testing.
*/
@VisibleForTesting(otherwise = VisibleForTesting.PRIVATE)
internal fun triggerPing() {
// Generate the activation_id.
Activation.activationId.generateAndSet()
CoroutineScope(Dispatchers.IO).launch {
val hashedId = getHashedIdentifier()
if (hashedId != null) {
Logger.info("ActivationPing - generating ping with the hashed id")
// We have a valid, hashed Google Advertising ID.
Activation.identifier.set(hashedId)
}
Logger.info("ActivationPing - generating ping (has `identifier`: ${hashedId != null})")
Pings.activation.submit()
markAsTriggered()
}
}
/**
* Trigger sending the `activation` ping if it wasn't sent already.
* Then, mark it so that it doesn't get triggered next time Fenix
* starts.
*/
fun checkAndSend() {
if (wasAlreadyTriggered()) {
Logger.debug("ActivationPing - already generated")
return
}
triggerPing()
}
}