Implement Android Credential Manager and Autofill providers (#109)

android/features/src/main/kotlin/de/rfc1437/ironstorage/features/CredentialSelectionScreen.kt

@@ -0,0 +1,172 @@
+package de.rfc1437.ironstorage.features
+
+import androidx.compose.foundation.layout.Arrangement
+import androidx.compose.foundation.layout.Row
+import androidx.compose.foundation.layout.fillMaxSize
+import androidx.compose.foundation.layout.fillMaxWidth
+import androidx.compose.foundation.layout.padding
+import androidx.compose.foundation.lazy.LazyColumn
+import androidx.compose.foundation.lazy.items
+import androidx.compose.foundation.selection.toggleable
+import androidx.compose.foundation.text.KeyboardOptions
+import androidx.compose.material3.Button
+import androidx.compose.material3.Checkbox
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.OutlinedTextField
+import androidx.compose.material3.Text
+import androidx.compose.material3.TextButton
+import androidx.compose.runtime.Composable
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.res.stringResource
+import androidx.compose.ui.semantics.Role
+import androidx.compose.ui.text.input.KeyboardType
+import androidx.compose.ui.text.input.PasswordVisualTransformation
+import androidx.compose.ui.unit.dp
+import de.rfc1437.ironstorage.core.ProviderRequest
+
+@Composable
+fun CredentialSelectionScreen(
+    request: ProviderRequest?,
+    saving: Boolean,
+    selected: String?,
+    query: String,
+    destination: String,
+    passphrase: String,
+    consent: Boolean,
+    overwrite: Boolean,
+    busy: Boolean,
+    failure: String?,
+    onSelect: (String?) -> Unit,
+    onQuery: (String) -> Unit,
+    onDestination: (String) -> Unit,
+    onPassphrase: (String) -> Unit,
+    onConsent: (Boolean) -> Unit,
+    onOverwrite: (Boolean) -> Unit,
+    onConfirm: () -> Unit,
+    onCancel: () -> Unit
+) {
+    LazyColumn(
+        Modifier.fillMaxSize().padding(24.dp),
+        verticalArrangement = Arrangement.spacedBy(12.dp)
+    ) {
+        item {
+            Text(
+                stringResource(
+                    if (saving) R.string.provider_save_title else R.string.provider_fill_title
+                ),
+                style = MaterialTheme.typography.headlineSmall
+            )
+            Text(request?.title ?: stringResource(R.string.provider_checking))
+        }
+        if (saving) {
+            item {
+                OutlinedTextField(
+                    destination,
+                    onDestination,
+                    label = { Text(stringResource(R.string.provider_destination)) },
+                    enabled = !busy,
+                    modifier = Modifier.fillMaxWidth(),
+                    singleLine = true
+                )
+                ProviderConsent(
+                    overwrite,
+                    !busy,
+                    stringResource(R.string.provider_overwrite),
+                    onOverwrite
+                )
+            }
+        } else if (selected == null) {
+            item {
+                OutlinedTextField(
+                    query,
+                    onQuery,
+                    label = { Text(stringResource(R.string.provider_search)) },
+                    enabled = !busy,
+                    modifier = Modifier.fillMaxWidth(),
+                    singleLine = true
+                )
+            }
+            items(request?.candidates ?: emptyList(), key = { it.path }) { candidate ->
+                TextButton(onClick = {
+                    onSelect(candidate.path)
+                }, enabled = !busy, modifier = Modifier.fillMaxWidth()) {
+                    Text(candidate.path)
+                }
+            }
+        } else {
+            item {
+                Text(stringResource(R.string.provider_selected, selected))
+                TextButton(onClick = { onSelect(null) }, enabled = !busy) {
+                    Text(stringResource(R.string.provider_choose_another))
+                }
+            }
+        }
+        if (saving || selected != null) {
+            item {
+                OutlinedTextField(
+                    passphrase,
+                    onPassphrase,
+                    label = { Text(stringResource(R.string.provider_passphrase)) },
+                    visualTransformation = PasswordVisualTransformation(),
+                    keyboardOptions = KeyboardOptions(
+                        keyboardType = KeyboardType.Password,
+                        autoCorrectEnabled = false
+                    ),
+                    enabled = !busy,
+                    modifier = Modifier.fillMaxWidth(),
+                    singleLine = true
+                )
+                val recipient = request?.title ?: stringResource(R.string.provider_this_application)
+                val confirmation = if (saving) {
+                    stringResource(
+                        R.string.provider_confirm_save
+                    )
+                } else {
+                    stringResource(R.string.provider_confirm_fill, recipient)
+                }
+                ProviderConsent(consent, !busy, confirmation, onConsent)
+            }
+        }
+        item {
+            failure?.let { Text(it, color = MaterialTheme.colorScheme.error) }
+            Button(
+                onClick = onConfirm,
+                enabled = !busy && consent && request != null &&
+                    (if (saving) destination.isNotBlank() else selected != null)
+            ) {
+                Text(
+                    stringResource(
+                        if (busy) {
+                            R.string.provider_working
+                        } else if (saving) {
+                            R.string.provider_save
+                        } else {
+                            R.string.provider_fill
+                        }
+                    )
+                )
+            }
+            TextButton(onClick = onCancel) { Text(stringResource(R.string.auth_cancel)) }
+        }
+    }
+}
+
+@Composable
+private fun ProviderConsent(
+    checked: Boolean,
+    enabled: Boolean,
+    label: String,
+    onChange: (Boolean) -> Unit
+) {
+    Row(
+        Modifier.fillMaxWidth().toggleable(
+            value = checked,
+            enabled = enabled,
+            role = Role.Checkbox,
+            onValueChange = onChange
+        )
+    ) {
+        Checkbox(checked, null, enabled = enabled)
+        Text(label, Modifier.padding(top = 12.dp))
+    }
+}

android/features/src/main/kotlin/de/rfc1437/ironstorage/features/SettingsScreen.kt

@@ -229,6 +229,13 @@ fun SettingsScreen(
                             }) { Text(stringResource(R.string.settings_rebuild)) }
                         }
                         "providers" -> {
+                            Text(stringResource(R.string.settings_chrome_guidance))
+                            TextButton(onClick = {
+                                uri.openUri(
+                                    "https://support.google.com/chrome/answer/142893?co=GENIE.Platform%3DAndroid&hl=en"
+                                )
+                            }) { Text(stringResource(R.string.settings_chrome_help)) }
+
                             page?.let {
                                 ProviderSetting(
                                     stringResource(R.string.settings_autofill),

android/features/src/main/res/values/strings.xml

@@ -156,7 +156,7 @@
     <string name="settings_git">Git commit author name and email</string>
     <string name="settings_auth">Authentication, inactivity timeout, biometrics and appearance</string>
     <string name="settings_cache">TOTP discovery cache</string>
-    <string name="settings_providers">Autofill and Credential Manager</string>
+    <string name="settings_providers">Autofill and Credential Manager providers</string>
     <string name="settings_recovery">Recovery and offline use</string>
     <string name="settings_about">Version, licenses, privacy and support</string>
     <string name="settings_no_token">No application token stored</string>
@@ -266,4 +266,21 @@
         <item quantity="one">%1$s password entry</item>
         <item quantity="other">%1$s password entries</item>
     </plurals>
+    <string name="settings_chrome_guidance">After selecting IronStorage in Android settings, open Chrome Settings → Autofill and passwords → Autofill settings. Select Autofill using another service and restart Chrome.</string>
+    <string name="settings_chrome_help">Chrome autofill help</string>
+    <string name="provider_fill_title">Fill from IronStorage</string>
+    <string name="provider_save_title">Save in IronStorage</string>
+    <string name="provider_checking">Checking the requesting application…</string>
+    <string name="provider_destination">Destination entry path</string>
+    <string name="provider_overwrite">Allow updating this destination if it exists</string>
+    <string name="provider_search">Search entries</string>
+    <string name="provider_selected">Selected: %1$s</string>
+    <string name="provider_choose_another">Choose another entry</string>
+    <string name="provider_passphrase">GPG passphrase (leave empty for biometric unlock)</string>
+    <string name="provider_this_application">this application</string>
+    <string name="provider_confirm_save">Save the supplied credential at the chosen destination</string>
+    <string name="provider_confirm_fill">Allow %1$s to receive this entry\'s username and password</string>
+    <string name="provider_working">Working…</string>
+    <string name="provider_save">Confirm save</string>
+    <string name="provider_fill">Unlock and fill</string>
 </resources>