Tell the user to set up syncing again if credentials can't be decrypted

If the keystore's secret is replaced -- say, after a keyring reset --
the stored value won't be able to be decrypted again, so tell them to
try logging in again instead of trying to fix their keyring.

https://forums.zotero.org/discussion/133603/

(cherry picked from commit fc17dcd24a)

chrome/content/zotero/xpcom/osKeyStore.js

@@ -101,6 +101,22 @@ Zotero.OSKeyStore = {
 		);
 	},
 
+	// Returns whether the store can actually be used. asyncSecretAvailable() isn't enough,
+	// since a locked or inaccessible store can still report a secret.
+	_usable: async function () {
+		let mod = this._load();
+		if (!mod) {
+			return false;
+		}
+		try {
+			await mod.encrypt('test');
+		}
+		catch {
+			return false;
+		}
+		return true;
+	},
+
 	// Mozilla's OSKeyStore reports every failure as a canceled unlock prompt, whatever the
 	// cause, so probe the native store to record what actually went wrong and return an error
 	// with a message that can be shown to the user
@@ -164,7 +180,13 @@ Zotero.OSKeyStore = {
 			binaryStr = await mod.decrypt(value.slice(this._prefix.length));
 		}
 		catch (e) {
-			throw await this._error(e, 'os-keystore-read-failed');
+			// A read can fail because the store is unusable or because the store is working
+			// and the stored value just can't be decrypted with the current key. Those need
+			// different advice, since fixing the store won't bring the value back.
+			let stringName = (await this._usable())
+				? 'os-keystore-read-unrecoverable'
+				: 'os-keystore-read-failed';
+			throw await this._error(e, stringName);
 		}
 		return new TextDecoder().decode(
 			Uint8Array.from(binaryStr, char => char.charCodeAt(0))

chrome/locale/en-US/zotero/zotero.ftl

@@ -1151,6 +1151,13 @@ os-keystore-read-failed =
        *[other] { -app-name } couldn’t access your { -os-name } keyring to read your saved credentials. Make sure a keyring service such as GNOME Keyring or KWallet is running and try again.
     }
 
+os-keystore-read-unrecoverable =
+    { PLATFORM() ->
+        [macos] { -app-name } couldn’t read your saved credentials from the { -os-name } Keychain.
+        [windows] { -app-name } couldn’t read your saved credentials from { -os-name } Credential Manager.
+       *[other] { -app-name } couldn’t read your saved credentials from your { -os-name } keyring.
+    } You’ll need to set up syncing again in the { -app-name } settings.
+
 os-keystore-save-unencrypted = { -app-name } can save your credentials unencrypted instead. Anyone with access to your { -app-name } profile folder would then be able to read them.
 
 os-keystore-save-unencrypted-button = Save Anyway

test/tests/webdavTest.js

@@ -266,12 +266,32 @@ describe("Zotero.Sync.Storage.Mode.WebDAV", function () {
 				this.skip();
 			}
 			await controller.setPassword("password");
-			var stub = sinon.stub(Zotero.OSKeyStore._module, "decrypt")
+			var decryptStub = sinon.stub(Zotero.OSKeyStore._module, "decrypt")
+				.rejects(new Error("User canceled OS unlock entry"));
+			var encryptStub = sinon.stub(Zotero.OSKeyStore._module, "encrypt")
 				.rejects(new Error("User canceled OS unlock entry"));
 			try {
 				let e = await getPromiseError(controller.getPassword());
 				assert.equal(e.message, Zotero.getString('os-keystore-read-failed'));
 			}
+			finally {
+				decryptStub.restore();
+				encryptStub.restore();
+			}
+		})
+		
+		
+		it("should tell the user to reenter a password the keystore can't decrypt", async function () {
+			if (!Zotero.OSKeyStore.available) {
+				this.skip();
+			}
+			await controller.setPassword("password");
+			var stub = sinon.stub(Zotero.OSKeyStore._module, "decrypt")
+				.rejects(new Error("User canceled OS unlock entry"));
+			try {
+				let e = await getPromiseError(controller.getPassword());
+				assert.equal(e.message, Zotero.getString('os-keystore-read-unrecoverable'));
+			}
 			finally {
 				stub.restore();
 			}