[pve-devel] [PATCH v2 widget-toolkit] tfa: improve UX for recovery keys and when none are left

[Wolfgang Bumiller <w.bumiller@proxmox.com>]

If we get an empty challenge, tell the user to contact an
administrator as it means no 2nd factors and no recovery
keys are available.

Currently if only 1 key was available and it had a high ID,
we'd show something like: "Recovery keys available: 9,
Warning, less than 4 keys available."
Let's start off with the warning, and then be explicit about
the IDs.

Signed-off-by: Wolfgang Bumiller <w.bumiller@proxmox.com>
---
Changes to v1 address Dominik's remarks:
  - Fix typos
  - Make generated ID list format string right-to-left compatible
  - Replace the pair of `hasAny2nd` and `hasNonRecovery2nd` with a
    counter and a `hasRecovery` boolean which allows expressing the
    condition that "either no 2nd factors, or only an already used up set of
    recovery keys exists" with less cognitive overhead.

 src/window/TfaWindow.js | 74 ++++++++++++++++++++++++++++++++---------
 1 file changed, 58 insertions(+), 16 deletions(-)

diff --git a/src/window/TfaWindow.js b/src/window/TfaWindow.js
index 22ac50d..a622ce1 100644
--- a/src/window/TfaWindow.js
+++ b/src/window/TfaWindow.js
@@ -45,11 +45,17 @@ Ext.define('Proxmox.window.TfaLoginWindow', {
 
 	    let lastTabId = me.getLastTabUsed();
 	    let initialTab = -1, i = 0;
+	    let count2nd = 0;
+	    let hasRecovery = false;
 	    for (const k of ['webauthn', 'totp', 'recovery', 'u2f', 'yubico']) {
 		const available = !!challenge[k];
 		vm.set(`availableChallenge.${k}`, available);
 
 		if (available) {
+		    count2nd++;
+		    if (k !== 'recovery') {
+			hasRecovery = true;
+		    }
 		    if (i === lastTabId) {
 			initialTab = i;
 		    } else if (initialTab < 0) {
@@ -58,15 +64,31 @@ Ext.define('Proxmox.window.TfaLoginWindow', {
 		}
 		i++;
 	    }
+	    if (!count2nd || (count2nd === 1 && hasRecovery && !challenge.recovery.length)) {
+		// no 2nd factors available (and if recovery keys are configured they're empty)
+		me.lookup('cannotLogin').setVisible(true);
+		me.lookup('recoveryKey').setVisible(false);
+		view.down('tabpanel').setActiveTab(2); // recovery
+		return;
+	    }
 	    view.down('tabpanel').setActiveTab(initialTab);
 
 	    if (challenge.recovery) {
-		me.lookup('availableRecovery').update(Ext.String.htmlEncode(
-		    gettext('Available recovery keys: ') + view.challenge.recovery.join(', '),
-		));
-		me.lookup('availableRecovery').setVisible(true);
-		if (view.challenge.recovery.length <= 3) {
-		    me.lookup('recoveryLow').setVisible(true);
+		if (!view.challenge.recovery.length) {
+		    me.lookup('recoveryEmpty').setVisible(true);
+		} else {
+		    let idList = view
+			    .challenge
+			    .recovery
+			    .map((id) => Ext.String.format(gettext('ID {0}'), id))
+			    .join(', ');
+		    me.lookup('availableRecovery').update(Ext.String.htmlEncode(
+			Ext.String.format(gettext('Available recovery keys: {0}'), idList),
+		    ));
+		    me.lookup('availableRecovery').setVisible(true);
+		    if (view.challenge.recovery.length <= 3) {
+			me.lookup('recoveryLow').setVisible(true);
+		    }
 		}
 	    }
 
@@ -365,19 +387,23 @@ Ext.define('Proxmox.window.TfaLoginWindow', {
 		items: [
 		    {
 			xtype: 'box',
-			reference: 'availableRecovery',
+			reference: 'cannotLogin',
 			hidden: true,
+			html: '<i class="fa fa-exclamation-triangle warning"></i>'
+			    + Ext.String.format(
+				gettext('No second factor left! Please contact an administrator!'),
+				4,
+			    ),
 		    },
 		    {
-			xtype: 'textfield',
-			fieldLabel: gettext('Please enter one of your single-use recovery keys'),
-			labelWidth: 300,
-			name: 'recoveryKey',
-			disabled: true,
-			reference: 'recoveryKey',
-			allowBlank: false,
-			regex: /^[0-9a-f]{4}(-[0-9a-f]{4}){3}$/,
-			regexText: gettext('Does not look like a valid recovery key'),
+			xtype: 'box',
+			reference: 'recoveryEmpty',
+			hidden: true,
+			html: '<i class="fa fa-exclamation-triangle warning"></i>'
+			    + Ext.String.format(
+				gettext('No more recovery keys left! Please generate a new set!'),
+				4,
+			    ),
 		    },
 		    {
 			xtype: 'box',
@@ -389,6 +415,22 @@ Ext.define('Proxmox.window.TfaLoginWindow', {
 				4,
 			    ),
 		    },
+		    {
+			xtype: 'box',
+			reference: 'availableRecovery',
+			hidden: true,
+		    },
+		    {
+			xtype: 'textfield',
+			fieldLabel: gettext('Please enter one of your single-use recovery keys'),
+			labelWidth: 300,
+			name: 'recoveryKey',
+			disabled: true,
+			reference: 'recoveryKey',
+			allowBlank: false,
+			regex: /^[0-9a-f]{4}(-[0-9a-f]{4}){3}$/,
+			regexText: gettext('Does not look like a valid recovery key'),
+		    },
 		],
 	    },
 	    {
-- 
2.30.2