Reintroduce TOTP support (#890)

Co-authored-by: Fabian Henneke <fabian@henneke.me>

11 files changed, 345 insertions, 94 deletions

diff --git a/app/src/main/java/com/zeapo/pwdstore/PasswordEntry.kt b/app/src/main/java/com/zeapo/pwdstore/PasswordEntry.kt
deleted file mode 100644
index d9168d39..00000000
--- a/app/src/main/java/com/zeapo/pwdstore/PasswordEntry.kt
+++ /dev/null
@@ -1,78 +0,0 @@
-/*
- * Copyright © 2014-2020 The Android Password Store Authors. All Rights Reserved.
- * SPDX-License-Identifier: GPL-3.0-only
- */
-package com.zeapo.pwdstore
-
-import java.io.ByteArrayOutputStream
-import java.io.UnsupportedEncodingException
-
-/**
- * A single entry in password store.
- */
-class PasswordEntry(content: String) {
-
-    val password: String
-    val username: String?
-    var extraContent: String
-        private set
-
-    @Throws(UnsupportedEncodingException::class)
-    constructor(os: ByteArrayOutputStream) : this(os.toString("UTF-8"))
-
-    init {
-        val passContent = content.split("\n".toRegex(), 2).toTypedArray()
-        password = passContent[0]
-        extraContent = findExtraContent(passContent)
-        username = findUsername()
-    }
-
-    fun hasExtraContent(): Boolean {
-        return extraContent.isNotEmpty()
-    }
-
-    fun hasUsername(): Boolean {
-        return username != null
-    }
-
-    val extraContentWithoutUsername by lazy {
-        var usernameFound = false
-        extraContent.splitToSequence("\n").filter { line ->
-            if (usernameFound)
-                return@filter true
-            if (USERNAME_FIELDS.any { prefix -> line.startsWith(prefix, ignoreCase = true) }) {
-                usernameFound = true
-                return@filter false
-            }
-            true
-        }.joinToString(separator = "\n")
-    }
-
-    private fun findUsername(): String? {
-        extraContent.splitToSequence("\n").forEach { line ->
-            for (prefix in USERNAME_FIELDS) {
-                if (line.startsWith(prefix, ignoreCase = true))
-                    return line.substring(prefix.length).trimStart()
-            }
-        }
-        return null
-    }
-
-    private fun findExtraContent(passContent: Array<String>): String {
-        return if (passContent.size > 1) passContent[1] else ""
-    }
-
-    companion object {
-        val USERNAME_FIELDS = arrayOf(
-            "login:",
-            "username:",
-            "user:",
-            "account:",
-            "email:",
-            "name:",
-            "handle:",
-            "id:",
-            "identity:"
-        )
-    }
-}
diff --git a/app/src/main/java/com/zeapo/pwdstore/autofill/AutofillService.kt b/app/src/main/java/com/zeapo/pwdstore/autofill/AutofillService.kt
index 26c86fc8..a58bde69 100644
--- a/app/src/main/java/com/zeapo/pwdstore/autofill/AutofillService.kt
+++ b/app/src/main/java/com/zeapo/pwdstore/autofill/AutofillService.kt
@@ -28,8 +28,8 @@ import com.github.ajalt.timberkt.Timber.tag
 import com.github.ajalt.timberkt.e
 import com.github.ajalt.timberkt.i
 import com.google.android.material.dialog.MaterialAlertDialogBuilder
-import com.zeapo.pwdstore.PasswordEntry
 import com.zeapo.pwdstore.R
+import com.zeapo.pwdstore.model.PasswordEntry
 import com.zeapo.pwdstore.utils.PasswordRepository
 import com.zeapo.pwdstore.utils.splitLines
 import kotlinx.coroutines.CoroutineScope
diff --git a/app/src/main/java/com/zeapo/pwdstore/autofill/oreo/AutofillHelper.kt b/app/src/main/java/com/zeapo/pwdstore/autofill/oreo/AutofillHelper.kt
index 101f96a0..d417484b 100644
--- a/app/src/main/java/com/zeapo/pwdstore/autofill/oreo/AutofillHelper.kt
+++ b/app/src/main/java/com/zeapo/pwdstore/autofill/oreo/AutofillHelper.kt
@@ -19,8 +19,8 @@ import androidx.annotation.RequiresApi
 import androidx.preference.PreferenceManager
 import com.github.ajalt.timberkt.Timber.tag
 import com.github.ajalt.timberkt.e
-import com.zeapo.pwdstore.PasswordEntry
 import com.zeapo.pwdstore.R
+import com.zeapo.pwdstore.model.PasswordEntry
 import com.zeapo.pwdstore.utils.PasswordRepository
 import java.io.File
 import java.security.MessageDigest
diff --git a/app/src/main/java/com/zeapo/pwdstore/autofill/oreo/ui/AutofillDecryptActivity.kt b/app/src/main/java/com/zeapo/pwdstore/autofill/oreo/ui/AutofillDecryptActivity.kt
index 4c806dff..b66d068b 100644
--- a/app/src/main/java/com/zeapo/pwdstore/autofill/oreo/ui/AutofillDecryptActivity.kt
+++ b/app/src/main/java/com/zeapo/pwdstore/autofill/oreo/ui/AutofillDecryptActivity.kt
@@ -16,12 +16,12 @@ import android.widget.Toast
 import androidx.annotation.RequiresApi
 import com.github.ajalt.timberkt.d
 import com.github.ajalt.timberkt.e
-import com.zeapo.pwdstore.PasswordEntry
 import com.zeapo.pwdstore.autofill.oreo.AutofillAction
 import com.zeapo.pwdstore.autofill.oreo.AutofillPreferences
 import com.zeapo.pwdstore.autofill.oreo.Credentials
 import com.zeapo.pwdstore.autofill.oreo.DirectoryStructure
 import com.zeapo.pwdstore.autofill.oreo.FillableForm
+import com.zeapo.pwdstore.model.PasswordEntry
 import kotlinx.coroutines.CoroutineScope
 import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.SupervisorJob
diff --git a/app/src/main/java/com/zeapo/pwdstore/crypto/BasePgpActivity.kt b/app/src/main/java/com/zeapo/pwdstore/crypto/BasePgpActivity.kt
index 5206a15f..fcadf119 100644
--- a/app/src/main/java/com/zeapo/pwdstore/crypto/BasePgpActivity.kt
+++ b/app/src/main/java/com/zeapo/pwdstore/crypto/BasePgpActivity.kt
@@ -17,6 +17,7 @@ import android.view.WindowManager
 import android.widget.Toast
 import androidx.activity.result.ActivityResultLauncher
 import androidx.annotation.CallSuper
+import androidx.annotation.StringRes
 import androidx.appcompat.app.AppCompatActivity
 import androidx.preference.PreferenceManager
 import com.github.ajalt.timberkt.Timber.tag
@@ -163,6 +164,7 @@ open class BasePgpActivity : AppCompatActivity(), OpenPgpServiceConnection.OnBou
 
         return DateUtils.getRelativeTimeSpanString(this, timeStamp, true)
     }
+
     /**
      * Base handling of OpenKeychain errors based on the error contained in [result]. Subclasses
      * can use this when they want to default to sane error handling.
@@ -190,12 +192,16 @@ open class BasePgpActivity : AppCompatActivity(), OpenPgpServiceConnection.OnBou
      * Copies provided [text] to the clipboard. Shows a [Snackbar] which can be disabled by passing
      * [showSnackbar] as false.
      */
-    fun copyTextToClipboard(text: String?, showSnackbar: Boolean = true) {
+    fun copyTextToClipboard(
+        text: String?,
+        showSnackbar: Boolean = true,
+        @StringRes snackbarTextRes: Int = R.string.clipboard_copied_text
+    ) {
         val clipboard = clipboard ?: return
         val clip = ClipData.newPlainText("pgp_handler_result_pm", text)
         clipboard.setPrimaryClip(clip)
         if (showSnackbar) {
-            snackbar(message = resources.getString(R.string.clipboard_copied_text))
+            snackbar(message = resources.getString(snackbarTextRes))
         }
     }
 
diff --git a/app/src/main/java/com/zeapo/pwdstore/crypto/DecryptActivity.kt b/app/src/main/java/com/zeapo/pwdstore/crypto/DecryptActivity.kt
index b7d7adcd..ad0b16f7 100644
--- a/app/src/main/java/com/zeapo/pwdstore/crypto/DecryptActivity.kt
+++ b/app/src/main/java/com/zeapo/pwdstore/crypto/DecryptActivity.kt
@@ -17,17 +17,23 @@ import androidx.activity.result.contract.ActivityResultContracts.StartActivityFo
 import androidx.activity.result.contract.ActivityResultContracts.StartIntentSenderForResult
 import androidx.lifecycle.lifecycleScope
 import com.github.ajalt.timberkt.e
-import com.zeapo.pwdstore.PasswordEntry
 import com.zeapo.pwdstore.R
 import com.zeapo.pwdstore.databinding.DecryptLayoutBinding
+import com.zeapo.pwdstore.model.PasswordEntry
+import com.zeapo.pwdstore.utils.Otp
 import com.zeapo.pwdstore.utils.viewBinding
 import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.delay
 import kotlinx.coroutines.launch
+import kotlinx.coroutines.withContext
 import me.msfjarvis.openpgpktx.util.OpenPgpApi
 import me.msfjarvis.openpgpktx.util.OpenPgpServiceConnection
 import org.openintents.openpgp.IOpenPgpService2
 import java.io.ByteArrayOutputStream
 import java.io.File
+import java.util.Date
+import kotlin.time.ExperimentalTime
+import kotlin.time.seconds
 
 class DecryptActivity : BasePgpActivity(), OpenPgpServiceConnection.OnBound {
     private val binding by viewBinding(DecryptLayoutBinding::inflate)
@@ -125,6 +131,7 @@ class DecryptActivity : BasePgpActivity(), OpenPgpServiceConnection.OnBound {
         startActivity(Intent.createChooser(sendIntent, resources.getText(R.string.send_plaintext_password_to)))
     }
 
+    @OptIn(ExperimentalTime::class)
     private fun decryptAndVerify(receivedIntent: Intent? = null) {
         if (api == null) {
             bindToOpenKeychain(this, openKeychainResult)
@@ -163,14 +170,16 @@ class DecryptActivity : BasePgpActivity(), OpenPgpServiceConnection.OnBound {
                                 }
 
                                 if (entry.hasExtraContent()) {
-                                    extraContentContainer.visibility = View.VISIBLE
-                                    extraContent.typeface = monoTypeface
-                                    extraContent.setText(entry.extraContentWithoutUsername)
-                                    if (!showExtraContent) {
-                                        extraContent.transformationMethod = PasswordTransformationMethod.getInstance()
+                                    if (entry.extraContentWithoutAuthData.isNotEmpty()) {
+                                        extraContentContainer.visibility = View.VISIBLE
+                                        extraContent.typeface = monoTypeface
+                                        extraContent.setText(entry.extraContentWithoutAuthData)
+                                        if (!showExtraContent) {
+                                            extraContent.transformationMethod = PasswordTransformationMethod.getInstance()
+                                        }
+                                        extraContentContainer.setOnClickListener { copyTextToClipboard(entry.extraContentWithoutAuthData) }
+                                        extraContent.setOnClickListener { copyTextToClipboard(entry.extraContentWithoutAuthData) }
                                     }
-                                    extraContentContainer.setOnClickListener { copyTextToClipboard(entry.extraContentWithoutUsername) }
-                                    extraContent.setOnClickListener { copyTextToClipboard(entry.extraContentWithoutUsername) }
 
                                     if (entry.hasUsername()) {
                                         usernameText.typeface = monoTypeface
@@ -180,6 +189,30 @@ class DecryptActivity : BasePgpActivity(), OpenPgpServiceConnection.OnBound {
                                     } else {
                                         usernameTextContainer.visibility = View.GONE
                                     }
+
+                                    if (entry.hasTotp()) {
+                                        otpTextContainer.visibility = View.VISIBLE
+                                        otpTextContainer.setEndIconOnClickListener {
+                                            copyTextToClipboard(
+                                                otpText.text.toString(),
+                                                snackbarTextRes = R.string.clipboard_otp_copied_text
+                                            )
+                                        }
+                                        launch(Dispatchers.IO) {
+                                            repeat(Int.MAX_VALUE) {
+                                                val code = Otp.calculateCode(
+                                                    entry.totpSecret!!,
+                                                    Date().time / (1000 * entry.totpPeriod),
+                                                    entry.totpAlgorithm,
+                                                    entry.digits
+                                                ) ?: "Error"
+                                                withContext(Dispatchers.Main) {
+                                                    otpText.setText(code)
+                                                }
+                                                delay(30.seconds)
+                                            }
+                                        }
+                                    }
                                 }
                             }
 
diff --git a/app/src/main/java/com/zeapo/pwdstore/crypto/PasswordCreationActivity.kt b/app/src/main/java/com/zeapo/pwdstore/crypto/PasswordCreationActivity.kt
index 67bf9926..81a73988 100644
--- a/app/src/main/java/com/zeapo/pwdstore/crypto/PasswordCreationActivity.kt
+++ b/app/src/main/java/com/zeapo/pwdstore/crypto/PasswordCreationActivity.kt
@@ -17,16 +17,16 @@ import androidx.core.widget.doOnTextChanged
 import androidx.lifecycle.lifecycleScope
 import com.github.ajalt.timberkt.e
 import com.google.android.material.dialog.MaterialAlertDialogBuilder
-import com.zeapo.pwdstore.PasswordEntry
-import com.zeapo.pwdstore.utils.isInsideRepository
 import com.zeapo.pwdstore.R
 import com.zeapo.pwdstore.autofill.oreo.AutofillPreferences
 import com.zeapo.pwdstore.autofill.oreo.DirectoryStructure
 import com.zeapo.pwdstore.databinding.PasswordCreationActivityBinding
+import com.zeapo.pwdstore.model.PasswordEntry
 import com.zeapo.pwdstore.ui.dialogs.PasswordGeneratorDialogFragment
 import com.zeapo.pwdstore.ui.dialogs.XkPasswordGeneratorDialogFragment
 import com.zeapo.pwdstore.utils.PasswordRepository
 import com.zeapo.pwdstore.utils.commitChange
+import com.zeapo.pwdstore.utils.isInsideRepository
 import com.zeapo.pwdstore.utils.snackbar
 import com.zeapo.pwdstore.utils.viewBinding
 import kotlinx.coroutines.Dispatchers
@@ -108,7 +108,7 @@ class PasswordCreationActivity : BasePgpActivity(), OpenPgpServiceConnection.OnB
                             // input lag.
                             if (username != null) {
                                 filename.setText(username)
-                                extraContent.setText(entry.extraContentWithoutUsername)
+                                extraContent.setText(entry.extraContentWithoutAuthData)
                             }
                         }
                         updateEncryptUsernameState()
diff --git a/app/src/main/java/com/zeapo/pwdstore/model/PasswordEntry.kt b/app/src/main/java/com/zeapo/pwdstore/model/PasswordEntry.kt
new file mode 100644
index 00000000..da2d57c6
--- /dev/null
+++ b/app/src/main/java/com/zeapo/pwdstore/model/PasswordEntry.kt
@@ -0,0 +1,113 @@
+/*
+ * Copyright © 2014-2020 The Android Password Store Authors. All Rights Reserved.
+ * SPDX-License-Identifier: GPL-3.0-only
+ */
+package com.zeapo.pwdstore.model
+
+import com.zeapo.pwdstore.utils.TotpFinder
+import com.zeapo.pwdstore.utils.UriTotpFinder
+import java.io.ByteArrayOutputStream
+import java.io.UnsupportedEncodingException
+
+/**
+ * A single entry in password store. [totpFinder] is an implementation of [TotpFinder] that let's us
+ * abstract out the Android-specific part and continue testing the class in the JVM.
+ */
+class PasswordEntry(content: String, private val totpFinder: TotpFinder = UriTotpFinder()) {
+
+    val password: String
+    val username: String?
+    val digits: String
+    val totpSecret: String?
+    val totpPeriod: Long
+    val totpAlgorithm: String
+    var extraContent: String
+        private set
+
+    @Throws(UnsupportedEncodingException::class)
+    constructor(os: ByteArrayOutputStream) : this(os.toString("UTF-8"), UriTotpFinder())
+
+    init {
+        val passContent = content.split("\n".toRegex(), 2).toTypedArray()
+        password = passContent[0]
+        extraContent = findExtraContent(passContent)
+        username = findUsername()
+        digits = findOtpDigits(content)
+        totpSecret = findTotpSecret(content)
+        totpPeriod = findTotpPeriod(content)
+        totpAlgorithm = findTotpAlgorithm(content)
+    }
+
+    fun hasExtraContent(): Boolean {
+        return extraContent.isNotEmpty()
+    }
+
+    fun hasTotp(): Boolean {
+        return totpSecret != null
+    }
+
+    fun hasUsername(): Boolean {
+        return username != null
+    }
+
+    val extraContentWithoutAuthData by lazy {
+        extraContent.splitToSequence("\n").filter { line ->
+            return@filter when {
+                USERNAME_FIELDS.any { prefix -> line.startsWith(prefix, ignoreCase = true) } -> {
+                    false
+                }
+                line.startsWith("otpauth://", ignoreCase = true) ||
+                    line.startsWith("totp:", ignoreCase = true) -> {
+                    false
+                }
+                else -> {
+                    true
+                }
+            }
+        }.joinToString(separator = "\n")
+    }
+
+    private fun findUsername(): String? {
+        extraContent.splitToSequence("\n").forEach { line ->
+            for (prefix in USERNAME_FIELDS) {
+                if (line.startsWith(prefix, ignoreCase = true))
+                    return line.substring(prefix.length).trimStart()
+            }
+        }
+        return null
+    }
+
+    private fun findExtraContent(passContent: Array<String>): String {
+        return if (passContent.size > 1) passContent[1] else ""
+    }
+
+    private fun findTotpSecret(decryptedContent: String): String? {
+        return totpFinder.findSecret(decryptedContent)
+    }
+
+    private fun findOtpDigits(decryptedContent: String): String {
+        return totpFinder.findDigits(decryptedContent)
+    }
+
+    private fun findTotpPeriod(decryptedContent: String): Long {
+        return totpFinder.findPeriod(decryptedContent)
+    }
+
+    private fun findTotpAlgorithm(decryptedContent: String): String {
+        return totpFinder.findAlgorithm(decryptedContent)
+    }
+
+    companion object {
+        val USERNAME_FIELDS = arrayOf(
+            "login:",
+            "username:",
+            "user:",
+            "account:",
+            "email:",
+            "name:",
+            "handle:",
+            "id:",
+            "identity:"
+        )
+    }
+}
diff --git a/app/src/main/java/com/zeapo/pwdstore/utils/Otp.kt b/app/src/main/java/com/zeapo/pwdstore/utils/Otp.kt
new file mode 100644
index 00000000..b95b9902
--- /dev/null
+++ b/app/src/main/java/com/zeapo/pwdstore/utils/Otp.kt
@@ -0,0 +1,88 @@
+/*
+ * Copyright © 2014-2020 The Android Password Store Authors. All Rights Reserved.
+ * SPDX-License-Identifier: GPL-3.0-only
+ */
+
+package com.zeapo.pwdstore.utils
+
+import com.github.ajalt.timberkt.e
+import org.apache.commons.codec.binary.Base32
+import java.nio.ByteBuffer
+import java.security.InvalidKeyException
+import java.security.NoSuchAlgorithmException
+import java.util.Locale
+import javax.crypto.Mac
+import javax.crypto.spec.SecretKeySpec
+import kotlin.experimental.and
+
+object Otp {
+    private val BASE_32 = Base32()
+    private val STEAM_ALPHABET = "23456789BCDFGHJKMNPQRTVWXY".toCharArray()
+    init {
+        check(STEAM_ALPHABET.size == 26)
+    }
+
+    fun calculateCode(secret: String, counter: Long, algorithm: String, digits: String): String? {
+        val algo = "Hmac${algorithm.toUpperCase(Locale.ROOT)}"
+        val decodedSecret = try {
+            BASE_32.decode(secret)
+        } catch (e: Exception) {
+            e(e) { "Failed to decode secret" }
+            return null
+        }
+        val secretKey = SecretKeySpec(decodedSecret, algo)
+        val digest = try {
+            Mac.getInstance(algo).run {
+                init(secretKey)
+                doFinal(ByteBuffer.allocate(8).putLong(counter).array())
+            }
+        } catch (e: NoSuchAlgorithmException) {
+            e(e)
+            return null
+        } catch (e: InvalidKeyException) {
+            e(e) { "Key is malformed" }
+            return null
+        }
+        // Least significant 4 bits are used as an offset into the digest.
+        val offset = (digest.last() and 0xf).toInt()
+        // Extract 32 bits at the offset and clear the most significant bit.
+        val code = digest.copyOfRange(offset, offset + 4)
+        code[0] = (0x7f and code[0].toInt()).toByte()
+        val codeInt = ByteBuffer.wrap(code).int
+        check(codeInt > 0)
+        return if (digits == "s") {
+            // Steam
+            var remainingCodeInt = codeInt
+            buildString {
+                repeat(5) {
+                    append(STEAM_ALPHABET[remainingCodeInt % 26])
+                    remainingCodeInt /= 26
+                }
+            }
+        } else {
+            // Base 10, 6 to 10 digits
+            val numDigits = digits.toIntOrNull()
+            when {
+                numDigits == null -> {
+                    e { "Digits specifier has to be either 's' or numeric" }
+                    return null
+                }
+                numDigits < 6 -> {
+                    e { "TOTP codes have to be at least 6 digits long" }
+                    return null
+                }
+                numDigits > 10 -> {
+                    e { "TOTP codes can be at most 10 digits long" }
+                    return null
+                }
+                else -> {
+                    // 2^31 = 2_147_483_648, so we can extract at most 10 digits with the first one
+                    // always being 0, 1, or 2. Pad with leading zeroes.
+                    val codeStringBase10 = codeInt.toString(10).padStart(10, '0')
+                    check(codeStringBase10.length == 10)
+                    codeStringBase10.takeLast(numDigits)
+                }
+            }
+        }
+    }
+}
diff --git a/app/src/main/java/com/zeapo/pwdstore/utils/TotpFinder.kt b/app/src/main/java/com/zeapo/pwdstore/utils/TotpFinder.kt
new file mode 100644
index 00000000..13a47543
--- /dev/null
+++ b/app/src/main/java/com/zeapo/pwdstore/utils/TotpFinder.kt
@@ -0,0 +1,32 @@
+/*
+ * Copyright © 2014-2020 The Android Password Store Authors. All Rights Reserved.
+ * SPDX-License-Identifier: GPL-3.0-only
+ */
+
+package com.zeapo.pwdstore.utils
+
+/**
+ * Defines a class that can extract relevant parts of a TOTP URL for use by the app.
+ */
+interface TotpFinder {
+
+    /**
+     * Get the TOTP secret from the given extra content.
+     */
+    fun findSecret(content: String): String?
+
+    /**
+     * Get the number of digits required in the final OTP.
+     */
+    fun findDigits(content: String): String
+
+    /**
+     * Get the TOTP timeout period.
+     */
+    fun findPeriod(content: String): Long
+
+    /**
+     * Get the algorithm for the TOTP secret.
+     */
+    fun findAlgorithm(content: String): String
+}
diff --git a/app/src/main/java/com/zeapo/pwdstore/utils/UriTotpFinder.kt b/app/src/main/java/com/zeapo/pwdstore/utils/UriTotpFinder.kt
new file mode 100644
index 00000000..faa349d1
--- /dev/null
+++ b/app/src/main/java/com/zeapo/pwdstore/utils/UriTotpFinder.kt
@@ -0,0 +1,57 @@
+/*
+ * Copyright © 2014-2020 The Android Password Store Authors. All Rights Reserved.
+ * SPDX-License-Identifier: GPL-3.0-only
+ */
+
+package com.zeapo.pwdstore.utils
+
+import android.net.Uri
+
+/**
+ * [Uri] backed TOTP URL parser.
+ */
+class UriTotpFinder : TotpFinder {
+    override fun findSecret(content: String): String? {
+        content.split("\n".toRegex()).forEach { line ->
+            if (line.startsWith("otpauth://totp/")) {
+                return Uri.parse(line).getQueryParameter("secret")
+            }
+            if (line.startsWith("totp:", ignoreCase = true)) {
+                return line.split(": *".toRegex(), 2).toTypedArray()[1]
+            }
+        }
+        return null
+    }
+
+    override fun findDigits(content: String): String {
+        content.split("\n".toRegex()).forEach { line ->
+            if (line.startsWith("otpauth://totp/") &&
+                Uri.parse(line).getQueryParameter("digits") != null) {
+                return Uri.parse(line).getQueryParameter("digits")!!
+            }
+        }
+        return "6"
+    }
+
+    override fun findPeriod(content: String): Long {
+        content.split("\n".toRegex()).forEach { line ->
+            if (line.startsWith("otpauth://totp/") &&
+                Uri.parse(line).getQueryParameter("period") != null) {
+                val period = Uri.parse(line).getQueryParameter("period")!!.toLongOrNull()
+                if (period != null && period > 0)
+                    return period
+            }
+        }
+        return 30
+    }
+
+    override fun findAlgorithm(content: String): String {
+        content.split("\n".toRegex()).forEach { line ->
+            if (line.startsWith("otpauth://totp/") &&
+                Uri.parse(line).getQueryParameter("algorithm") != null) {
+                return Uri.parse(line).getQueryParameter("algorithm")!!
+            }
+        }
+        return "sha1"
+    }
+}