AssistStructureParser.kt

1package com.peachpasswords.autofill23import android.app.assist.AssistStructure4import android.text.InputType5import android.view.View6import android.view.autofill.AutofillId78/**9* The autofillable fields discovered in one [AssistStructure], plus the origin10* Android authenticated for ranking vault entries.11 *12 * Origin verification was removed (queue #3, June 2026-08-02): matches are13 * ranked by [originDomains] (the page domain, or a native app's app-link14 * domains) and [appTitle] (a native app's display label), with no caller-trust15 * gate. [originDomains]/[appTitle] are populated by the service, not the parser.16*/17data class ParsedStructure(18    val usernameId: AutofillId? = null,19    val emailId: AutofillId? = null,20    val passwordId: AutofillId? = null,21    val otpId: AutofillId? = null,22    /** Split single-character OTP boxes in traversal order (browser A6 parity). */23    val otpDigitBoxIds: List<AutofillId> = emptyList(),24    val usernameValue: String? = null,25    val emailValue: String? = null,26    val passwordValue: String? = null,27    val otpValue: String? = null,28    val passwordPolicy: PasswordPolicy? = null,29    val isNewPassword: Boolean = false,30    val webDomain: String? = null,31    val packageName: String? = null,32    val appTitle: String? = null,33    val originDomains: List<String> = emptyList(),34    val cardNumberId: AutofillId? = null,35    val cardExpMonthId: AutofillId? = null,36    val cardExpYearId: AutofillId? = null,37    val cardExpDateId: AutofillId? = null,38    val cardCvcId: AutofillId? = null,39    val cardNameId: AutofillId? = null,40) {41    /** The id we put the account identifier into — email preferred, else username. */42    val identityId: AutofillId? get() = emailId ?: usernameId43    /**44     * Forms that earn an autofill response: a password field (login/signup),45     * an OTP field (2FA entry), or card fields. Bare text/identity fields —46     * chat composers, search boxes — never get a suggestion (the Discord47     * message-input false positive).48     */49    val hasCredentialField: Boolean get() = passwordId != null || otpId != null || otpDigitBoxIds.isNotEmpty() || hasCardField50    val hasCardField: Boolean get() = cardNumberId != null || cardExpMonthId != null ||51        cardExpYearId != null || cardExpDateId != null || cardCvcId != null || cardNameId != null52    /** Best label to rank entries against. */53    val origin: String? get() = webDomain ?: packageName54}5556/**57 * Walks an [AssistStructure] to classify username/email/password/OTP/card fields.58 * Mirrors the browser content-script's field detection: trust explicit autofill59 * hints first, then fall back to input-type and id/hint keyword heuristics so60 * unannotated login forms still work.61 */62object AssistStructureParser {6364    fun parse(structure: AssistStructure): ParsedStructure {65        // View-node package ids are supplied by the foreground app; the framework-owned66        // activity component is the authenticated caller identity.67        var result = ParsedStructure(68            packageName = authenticatedPackageName(structure.activityComponent?.packageName),69        )70        val windows = structure.windowNodeCount71        for (i in 0 until windows) {72            val root = structure.getWindowNodeAt(i).rootViewNode73            result = traverse(root, result)74        }75        // Browser parity: a split-OTP group is 4-10 single-character boxes.76        if (result.otpDigitBoxIds.size !in 4..10) {77            result = result.copy(otpDigitBoxIds = emptyList())78        }79        return result80    }8182    private fun traverse(node: AssistStructure.ViewNode, acc: ParsedStructure): ParsedStructure {83        var result = acc84        if (result.webDomain == null && !node.webDomain.isNullOrBlank()) {85            result = result.copy(webDomain = node.webDomain)86        }8788        val id = node.autofillId89        if (id != null && isFillable(node)) {90            if (isDigitBoxCandidate(node)) {91                result = result.copy(otpDigitBoxIds = result.otpDigitBoxIds + id)92            } else {93            val value = node.autofillValue?.takeIf { it.isText }?.textValue?.toString()94                ?: node.text?.toString()95            result = when (classify(node)) {96                FieldKind.PASSWORD -> if (result.passwordId == null) {97                    val attrs = htmlAttributes(node)98                    result.copy(99                        passwordId = id,100                        passwordValue = value,101                        passwordPolicy = PasswordPolicy.fromHtmlAttributes(attrs)102                            .takeIf { it.minLength != null || it.maxLength != null },103                        isNewPassword = attrs["autocomplete"]104                            ?.contains("new-password", ignoreCase = true) == true,105                    )106                } else result107                FieldKind.USERNAME -> if (result.usernameId == null) result.copy(usernameId = id, usernameValue = value) else result108                FieldKind.EMAIL -> if (result.emailId == null) result.copy(emailId = id, emailValue = value) else result109                FieldKind.OTP -> if (result.otpId == null) result.copy(otpId = id, otpValue = value) else result110                FieldKind.CARD_NUMBER -> if (result.cardNumberId == null) result.copy(cardNumberId = id) else result111                FieldKind.CARD_EXP_MONTH -> if (result.cardExpMonthId == null) result.copy(cardExpMonthId = id) else result112                FieldKind.CARD_EXP_YEAR -> if (result.cardExpYearId == null) result.copy(cardExpYearId = id) else result113                FieldKind.CARD_EXP_DATE -> if (result.cardExpDateId == null) result.copy(cardExpDateId = id) else result114                FieldKind.CARD_CVC -> if (result.cardCvcId == null) result.copy(cardCvcId = id) else result115                FieldKind.CARD_NAME -> if (result.cardNameId == null) result.copy(cardNameId = id) else result116                FieldKind.NONE -> result117            }118            }119        }120121        for (i in 0 until node.childCount) {122            result = traverse(node.getChildAt(i), result)123        }124        return result125    }126127    private fun isFillable(node: AssistStructure.ViewNode): Boolean =128        node.autofillType == View.AUTOFILL_TYPE_TEXT &&129            node.visibility == View.VISIBLE130131    /**132     * A web field's HTML attributes (minlength/maxlength/pattern/autocomplete…),133     * lower-cased by key. Empty for native views — [ViewNode.getHtmlInfo] is only134     * populated for web content, so policy detection degrades to "no constraint".135     */136    private fun htmlAttributes(node: AssistStructure.ViewNode): Map<String, String> {137        val info = node.htmlInfo ?: return emptyMap()138        val out = mutableMapOf<String, String>()139        for (attr in info.attributes.orEmpty()) {140            val key = attr.first?.lowercase() ?: continue141            val value = attr.second ?: continue142            out[key] = value143        }144        return out145    }146147    /**148     * A single-character input in a split-OTP group (browser's149     * findOTPDigitBoxGroup). Web: maxlength=1 with a text/number/tel type.150     * Native: numeric input type, but only when unlabeled or OTP-labeled —151     * labeled numeric fields (card number, expiry) still go through [classify].152     * The 4..10 group gate in [parse] keeps stray singles out.153     */154    private fun isDigitBoxCandidate(node: AssistStructure.ViewNode): Boolean {155        val attrs = htmlAttributes(node)156        if (attrs.isNotEmpty()) {157            if (attrs["maxlength"] != "1") return false158            return (attrs["type"]?.lowercase() ?: "") in setOf("", "text", "number", "tel")159        }160        if (node.autofillHints?.any { it.equals("smsOTPCode", true) || it.equals("oneTimeCode", true) } == true) {161            return true162        }163        val type = node.inputType164        if (type and InputType.TYPE_MASK_VARIATION == InputType.TYPE_NUMBER_VARIATION_PASSWORD) return false165        if (type and InputType.TYPE_MASK_CLASS != InputType.TYPE_CLASS_NUMBER) return false166        val haystack = listOfNotNull(node.idEntry, node.hint, node.text?.toString())167            .joinToString(" ").lowercase()168        return haystack.isBlank() ||169            Regex("\b(otp|2fa|mfa|one[- ]?time|verification code|auth code|pin)\b").containsMatchIn(haystack)170    }171172    private enum class FieldKind { USERNAME, EMAIL, PASSWORD, OTP, CARD_NUMBER, CARD_EXP_MONTH, CARD_EXP_YEAR, CARD_EXP_DATE, CARD_CVC, CARD_NAME, NONE }173174    private fun classify(node: AssistStructure.ViewNode): FieldKind {175        node.autofillHints?.forEach { hint ->176            when (hint.lowercase()) {177                View.AUTOFILL_HINT_PASSWORD, "password" -> return FieldKind.PASSWORD178                View.AUTOFILL_HINT_USERNAME, "username" -> return FieldKind.USERNAME179                View.AUTOFILL_HINT_EMAIL_ADDRESS, "email", "emailaddress" -> return FieldKind.EMAIL180                "otp", "smsotpcode", "2facode",181                "one-time-password", "one_time_password", "totp" -> return FieldKind.OTP182                View.AUTOFILL_HINT_CREDIT_CARD_NUMBER, "creditcardnumber", "ccnumber" -> return FieldKind.CARD_NUMBER183                View.AUTOFILL_HINT_CREDIT_CARD_EXPIRATION_MONTH, "creditcardexpirationmonth" -> return FieldKind.CARD_EXP_MONTH184                View.AUTOFILL_HINT_CREDIT_CARD_EXPIRATION_YEAR, "creditcardexpirationyear" -> return FieldKind.CARD_EXP_YEAR185                View.AUTOFILL_HINT_CREDIT_CARD_EXPIRATION_DATE, "creditcardexpirationdate" -> return FieldKind.CARD_EXP_DATE186                View.AUTOFILL_HINT_CREDIT_CARD_SECURITY_CODE, "creditcardsecuritycode", "ccsecuritycode" -> return FieldKind.CARD_CVC187            }188        }189190        val type = node.inputType191        val isPasswordType = type and InputType.TYPE_MASK_VARIATION == InputType.TYPE_TEXT_VARIATION_PASSWORD ||192            type and InputType.TYPE_MASK_VARIATION == InputType.TYPE_TEXT_VARIATION_WEB_PASSWORD ||193            type and InputType.TYPE_MASK_VARIATION == InputType.TYPE_NUMBER_VARIATION_PASSWORD194        if (isPasswordType) return FieldKind.PASSWORD195196        val haystack = listOfNotNull(node.idEntry, node.hint, node.text?.toString())197            .joinToString(" ").lowercase()198        return when {199            haystack.isBlank() -> FieldKind.NONE200            // OTP/2FA haystack: cover the labels real 2FA forms actually use,201            // not just the textbook ones. The framework only sets "otp" hint202            // when the developer opts in to autofill; most don't, so the field203            // ends up with a generic label and a missed detection. Standalone204            // "code" is intentionally absent -- promo / coupon / discount codes205            // match it too and would mis-fill with a TOTP.206            OTP_HAYSTACK_RX.containsMatchIn(haystack) -> FieldKind.OTP207            haystack.contains("password") || haystack.contains("passwd") || haystack.contains("pwd") -> FieldKind.PASSWORD208            haystack.contains("email") || haystack.contains("e-mail") -> FieldKind.EMAIL209            haystack.contains("user") || haystack.contains("login") || haystack.contains("account") -> FieldKind.USERNAME210            CARD_NUMBER_RX.containsMatchIn(haystack) -> FieldKind.CARD_NUMBER211            CARD_EXP_MONTH_RX.containsMatchIn(haystack) -> FieldKind.CARD_EXP_MONTH212            CARD_EXP_YEAR_RX.containsMatchIn(haystack) -> FieldKind.CARD_EXP_YEAR213            CARD_EXP_DATE_RX.containsMatchIn(haystack) -> FieldKind.CARD_EXP_DATE214            CARD_CVC_RX.containsMatchIn(haystack) -> FieldKind.CARD_CVC215            CARD_NAME_RX.containsMatchIn(haystack) -> FieldKind.CARD_NAME216            else -> FieldKind.NONE217        }218    }219220    /**221     * Heuristic for OTP / 2FA fields. Covers the labels real 2FA forms222     * actually use -- not just the textbook ones. Standalone "code" is223     * intentionally absent (promo / coupon / discount codes would mis-match).224     */225    internal val OTP_HAYSTACK_RX = Regex(226        "\\b(otp|2fa|mfa|one[- ]?time|verification|auth(entication)?|security code|token|confirm)\\b",227    )228229    private val CARD_NUMBER_RX = Regex("\\b(card\\s*number|credit\\s*card|card\\s*no|pan|cc\\s*num)\\b")230    private val CARD_EXP_MONTH_RX = Regex("\\b(exp\\s*month|expiration\\s*month|expiry\\s*month)\\b")231    private val CARD_EXP_YEAR_RX = Regex("\\b(exp\\s*year|expiration\\s*year|expiry\\s*year)\\b")232    private val CARD_EXP_DATE_RX = Regex("\\b(exp\\s*date|expiration\\s*date|expiry\\s*date|exp\\b)")233    private val CARD_CVC_RX = Regex("\\b(cvc|cvv|security\\s*code|card\\s*code)\\b")234    private val CARD_NAME_RX = Regex("\\b(cardholder|card\\s*holder|name\\s*on\\s*card|card\\s*name)\\b")235}236237/**238 * The framework-owned activity component is the caller identity. Never infer239 * the package from a view node or an autofill hint: those are host-controlled240 * form metadata and cannot authenticate an origin.241 */242internal fun authenticatedPackageName(packageName: String?): String? =243    packageName?.takeIf { it.isNotBlank() }