AssistStructureParser.kt

1package com.peachpasswords.autofill23import android.app.assist.AssistStructure4import android.text.InputType5import android.view.View6import android.view.autofill.AutofillId78enum class AutofillOriginTrust { TRUSTED_WEB, TRUSTED_NATIVE, UNKNOWN }910/**11 * The autofillable fields discovered in one [AssistStructure], plus the origin12 * Android authenticated for ranking vault entries.13 */14data class ParsedStructure(15    val usernameId: AutofillId? = null,16    val emailId: AutofillId? = null,17    val passwordId: AutofillId? = null,18    val otpId: AutofillId? = null,19    val usernameValue: String? = null,20    val emailValue: String? = null,21    val passwordValue: String? = null,22    val otpValue: String? = null,23    val passwordPolicy: PasswordPolicy? = null,24    val isNewPassword: Boolean = false,25    val webDomain: String? = null,26    val packageName: String? = null,27    val originTrust: AutofillOriginTrust = AutofillOriginTrust.UNKNOWN,28    val verifiedDomains: List<String> = emptyList(),29    val cardNumberId: AutofillId? = null,30    val cardExpMonthId: AutofillId? = null,31    val cardExpYearId: AutofillId? = null,32    val cardExpDateId: AutofillId? = null,33    val cardCvcId: AutofillId? = null,34    val cardNameId: AutofillId? = null,35) {36    /** The id we put the account identifier into — email preferred, else username. */37    val identityId: AutofillId? get() = emailId ?: usernameId38    val hasUsableField: Boolean get() = passwordId != null || identityId != null || otpId != null || hasCardField39    val hasCardField: Boolean get() = cardNumberId != null || cardExpMonthId != null ||40        cardExpYearId != null || cardExpDateId != null || cardCvcId != null || cardNameId != null41    /** Best label to rank entries against. */42    val origin: String? get() = webDomain ?: packageName43}4445/**46 * Walks an [AssistStructure] to classify username/email/password/OTP/card fields.47 * Mirrors the browser content-script's field detection: trust explicit autofill48 * hints first, then fall back to input-type and id/hint keyword heuristics so49 * unannotated login forms still work.50 */51object AssistStructureParser {5253    fun parse(structure: AssistStructure): ParsedStructure {54        // View-node package ids are supplied by the foreground app; the framework-owned55        // activity component is the authenticated caller identity.56        var result = ParsedStructure(57            packageName = authenticatedPackageName(structure.activityComponent?.packageName),58        )59        val windows = structure.windowNodeCount60        for (i in 0 until windows) {61            val root = structure.getWindowNodeAt(i).rootViewNode62            result = traverse(root, result)63        }64        return result65    }6667    private fun traverse(node: AssistStructure.ViewNode, acc: ParsedStructure): ParsedStructure {68        var result = acc69        if (result.webDomain == null && !node.webDomain.isNullOrBlank()) {70            result = result.copy(webDomain = node.webDomain)71        }7273        val id = node.autofillId74        if (id != null && isFillable(node)) {75            val value = node.autofillValue?.takeIf { it.isText }?.textValue?.toString()76                ?: node.text?.toString()77            result = when (classify(node)) {78                FieldKind.PASSWORD -> if (result.passwordId == null) {79                    val attrs = htmlAttributes(node)80                    result.copy(81                        passwordId = id,82                        passwordValue = value,83                        passwordPolicy = PasswordPolicy.fromHtmlAttributes(attrs)84                            .takeIf { it.minLength != null || it.maxLength != null },85                        isNewPassword = attrs["autocomplete"]86                            ?.contains("new-password", ignoreCase = true) == true,87                    )88                } else result89                FieldKind.USERNAME -> if (result.usernameId == null) result.copy(usernameId = id, usernameValue = value) else result90                FieldKind.EMAIL -> if (result.emailId == null) result.copy(emailId = id, emailValue = value) else result91                FieldKind.OTP -> if (result.otpId == null) result.copy(otpId = id, otpValue = value) else result92                FieldKind.CARD_NUMBER -> if (result.cardNumberId == null) result.copy(cardNumberId = id) else result93                FieldKind.CARD_EXP_MONTH -> if (result.cardExpMonthId == null) result.copy(cardExpMonthId = id) else result94                FieldKind.CARD_EXP_YEAR -> if (result.cardExpYearId == null) result.copy(cardExpYearId = id) else result95                FieldKind.CARD_EXP_DATE -> if (result.cardExpDateId == null) result.copy(cardExpDateId = id) else result96                FieldKind.CARD_CVC -> if (result.cardCvcId == null) result.copy(cardCvcId = id) else result97                FieldKind.CARD_NAME -> if (result.cardNameId == null) result.copy(cardNameId = id) else result98                FieldKind.NONE -> result99            }100        }101102        for (i in 0 until node.childCount) {103            result = traverse(node.getChildAt(i), result)104        }105        return result106    }107108    private fun isFillable(node: AssistStructure.ViewNode): Boolean =109        node.autofillType == View.AUTOFILL_TYPE_TEXT &&110            node.visibility == View.VISIBLE111112    /**113     * A web field's HTML attributes (minlength/maxlength/pattern/autocomplete…),114     * lower-cased by key. Empty for native views — [ViewNode.getHtmlInfo] is only115     * populated for web content, so policy detection degrades to "no constraint".116     */117    private fun htmlAttributes(node: AssistStructure.ViewNode): Map<String, String> {118        val info = node.htmlInfo ?: return emptyMap()119        val out = mutableMapOf<String, String>()120        for (attr in info.attributes.orEmpty()) {121            val key = attr.first?.lowercase() ?: continue122            val value = attr.second ?: continue123            out[key] = value124        }125        return out126    }127128    private enum class FieldKind { USERNAME, EMAIL, PASSWORD, OTP, CARD_NUMBER, CARD_EXP_MONTH, CARD_EXP_YEAR, CARD_EXP_DATE, CARD_CVC, CARD_NAME, NONE }129130    private fun classify(node: AssistStructure.ViewNode): FieldKind {131        node.autofillHints?.forEach { hint ->132            when (hint.lowercase()) {133                View.AUTOFILL_HINT_PASSWORD, "password" -> return FieldKind.PASSWORD134                View.AUTOFILL_HINT_USERNAME, "username" -> return FieldKind.USERNAME135                View.AUTOFILL_HINT_EMAIL_ADDRESS, "email", "emailaddress" -> return FieldKind.EMAIL136                "otp", "smsotpcode", "2facode" -> return FieldKind.OTP137                View.AUTOFILL_HINT_CREDIT_CARD_NUMBER, "creditcardnumber", "ccnumber" -> return FieldKind.CARD_NUMBER138                View.AUTOFILL_HINT_CREDIT_CARD_EXPIRATION_MONTH, "creditcardexpirationmonth" -> return FieldKind.CARD_EXP_MONTH139                View.AUTOFILL_HINT_CREDIT_CARD_EXPIRATION_YEAR, "creditcardexpirationyear" -> return FieldKind.CARD_EXP_YEAR140                View.AUTOFILL_HINT_CREDIT_CARD_EXPIRATION_DATE, "creditcardexpirationdate" -> return FieldKind.CARD_EXP_DATE141                View.AUTOFILL_HINT_CREDIT_CARD_SECURITY_CODE, "creditcardsecuritycode", "ccsecuritycode" -> return FieldKind.CARD_CVC142            }143        }144145        val type = node.inputType146        val isPasswordType = type and InputType.TYPE_MASK_VARIATION == InputType.TYPE_TEXT_VARIATION_PASSWORD ||147            type and InputType.TYPE_MASK_VARIATION == InputType.TYPE_TEXT_VARIATION_WEB_PASSWORD ||148            type and InputType.TYPE_MASK_VARIATION == InputType.TYPE_NUMBER_VARIATION_PASSWORD149        if (isPasswordType) return FieldKind.PASSWORD150151        val haystack = listOfNotNull(node.idEntry, node.hint, node.text?.toString())152            .joinToString(" ").lowercase()153        return when {154            haystack.isBlank() -> FieldKind.NONE155            Regex("\\b(otp|2fa|mfa|one[- ]?time|verification code|auth code)\\b").containsMatchIn(haystack) -> FieldKind.OTP156            haystack.contains("password") || haystack.contains("passwd") || haystack.contains("pwd") -> FieldKind.PASSWORD157            haystack.contains("email") || haystack.contains("e-mail") -> FieldKind.EMAIL158            haystack.contains("user") || haystack.contains("login") || haystack.contains("account") -> FieldKind.USERNAME159            CARD_NUMBER_RX.containsMatchIn(haystack) -> FieldKind.CARD_NUMBER160            CARD_EXP_MONTH_RX.containsMatchIn(haystack) -> FieldKind.CARD_EXP_MONTH161            CARD_EXP_YEAR_RX.containsMatchIn(haystack) -> FieldKind.CARD_EXP_YEAR162            CARD_EXP_DATE_RX.containsMatchIn(haystack) -> FieldKind.CARD_EXP_DATE163            CARD_CVC_RX.containsMatchIn(haystack) -> FieldKind.CARD_CVC164            CARD_NAME_RX.containsMatchIn(haystack) -> FieldKind.CARD_NAME165            else -> FieldKind.NONE166        }167    }168169    private val CARD_NUMBER_RX = Regex("\\b(card\\s*number|credit\\s*card|card\\s*no|pan|cc\\s*num)\\b")170    private val CARD_EXP_MONTH_RX = Regex("\\b(exp\\s*month|expiration\\s*month|expiry\\s*month)\\b")171    private val CARD_EXP_YEAR_RX = Regex("\\b(exp\\s*year|expiration\\s*year|expiry\\s*year)\\b")172    private val CARD_EXP_DATE_RX = Regex("\\b(exp\\s*date|expiration\\s*date|expiry\\s*date|exp\\b)")173    private val CARD_CVC_RX = Regex("\\b(cvc|cvv|security\\s*code|card\\s*code)\\b")174    private val CARD_NAME_RX = Regex("\\b(cardholder|card\\s*holder|name\\s*on\\s*card|card\\s*name)\\b")175}176177/**178 * The framework-owned activity component is the caller identity. Never infer179 * the package from a view node or an autofill hint: those are host-controlled180 * form metadata and cannot authenticate an origin.181 */182internal fun authenticatedPackageName(packageName: String?): String? =183    packageName?.takeIf { it.isNotBlank() }