diff options
Diffstat (limited to 'app/src/main/kotlin/com/pitchedapps/frost/injectors/JsInjector.kt')
-rw-r--r-- | app/src/main/kotlin/com/pitchedapps/frost/injectors/JsInjector.kt | 48 |
1 files changed, 43 insertions, 5 deletions
diff --git a/app/src/main/kotlin/com/pitchedapps/frost/injectors/JsInjector.kt b/app/src/main/kotlin/com/pitchedapps/frost/injectors/JsInjector.kt index 00c7bcfc..3416c420 100644 --- a/app/src/main/kotlin/com/pitchedapps/frost/injectors/JsInjector.kt +++ b/app/src/main/kotlin/com/pitchedapps/frost/injectors/JsInjector.kt @@ -17,9 +17,11 @@ package com.pitchedapps.frost.injectors import android.webkit.WebView +import androidx.annotation.VisibleForTesting +import com.pitchedapps.frost.utils.L import com.pitchedapps.frost.web.FrostWebViewClient import org.apache.commons.text.StringEscapeUtils -import java.util.Locale +import kotlin.random.Random class JsBuilder { private val css = StringBuilder() @@ -38,7 +40,7 @@ class JsBuilder { } fun single(tag: String): JsBuilder { - this.tag = "_frost_${tag.toLowerCase(Locale.CANADA)}" + this.tag = TagObfuscator.obfuscateTag(tag) return this } @@ -52,14 +54,19 @@ class JsBuilder { val cssMin = css.replace(Regex("\\s*\n\\s*"), "") append("var a=document.createElement('style');") append("a.innerHTML='$cssMin';") - if (tag != null) append("a.id='$tag';") + if (tag != null) { + append("a.id='$tag';") + } append("document.head.appendChild(a);") } - if (js.isNotBlank()) + if (js.isNotBlank()) { append(js) + } } var content = builder.append("}()").toString() - if (tag != null) content = singleInjector(tag, content) + if (tag != null) { + content = singleInjector(tag, content) + } return content } @@ -102,3 +109,34 @@ class JsInjector(val function: String) : InjectorContract { override fun inject(webView: WebView) = webView.evaluateJavascript(function, null) } + +/** + * Helper object to obfuscate window tags for JS injection. + */ +@VisibleForTesting +internal object TagObfuscator { + + fun obfuscateTag(tag: String): String { + val rnd = Random(tag.hashCode() + salt) + val obfuscated = buildString { + append(prefix) + append('_') + appendRandomChars(rnd, 16) + } + L.v { "TagObfuscator: Obfuscating tag '$tag' to '$obfuscated'" } + return obfuscated + } + + private val salt: Long = System.currentTimeMillis() + + private val prefix: String by lazy { + val rnd = Random(System.currentTimeMillis()) + buildString { appendRandomChars(rnd, 8) } + } + + private fun Appendable.appendRandomChars(random: Random, count: Int) { + for (i in 1..count) { + append('a' + random.nextInt(26)) + } + } +} |