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#3598 encryption: add new note encryption with portable versioned encryption envelope
Signed-off-by: Patrizio Bekerle <patrizio@bekerle.com>
1 parent 5d8ef09 commit 26a18e6

6 files changed

Lines changed: 335 additions & 49 deletions

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‎CHANGELOG.md‎

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Original file line numberDiff line numberDiff line change
@@ -2,6 +2,10 @@
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## 26.5.3
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- New note encryption now writes a portable versioned encryption envelope with
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per-note salt and nonce metadata, derives keys with Botan PBKDF2-HMAC-SHA1,
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and encrypts with AES-256-CBC plus HMAC authentication while keeping legacy
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encrypted notes decryptable (for [#3598](https://github.com/pbek/QOwnNotes/issues/3598))
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- Secrets such as cloud connection passwords, proxy passwords, API keys, and
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scripting secret settings are now stored in the operating system keychain via
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qtkeychain instead of being obfuscated with SimpleCrypt in the settings file;

‎src/entities/note.cpp‎

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@@ -71,6 +71,24 @@ struct ParsedWikiLink {
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WikiLinkParts parts;
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};
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struct NoteEncryptionEnvelope {
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bool isV2 = false;
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QString cipherText;
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QString kdf;
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QString cipher;
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QString salt;
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QString nonce;
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QString mac;
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size_t iterations = 0;
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};
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constexpr int NoteEncryptionVersion = 2;
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constexpr int NoteEncryptionSaltBytes = 32;
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constexpr int NoteEncryptionNonceBytes = 16;
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constexpr size_t NoteEncryptionKdfIterations = 300000;
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const auto NoteEncryptionKdf = QStringLiteral("PBKDF2-HMAC-SHA1");
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const auto NoteEncryptionCipher = QStringLiteral("AES-256-CBC-PKCS7-HMAC-SHA1");
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7492
static const QRegularExpression &wikiLinkRegex() {
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static const QRegularExpression regex(QStringLiteral(R"(\[\[([^\[\]]+?)\]\])"));
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return regex;
@@ -317,6 +335,79 @@ static QString postProcessWikiLinksHtml(QString html, int currentNoteSubFolderId
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return html;
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}
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static NoteEncryptionEnvelope parseNoteEncryptionEnvelope(const QString &payload) {
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NoteEncryptionEnvelope envelope;
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envelope.cipherText = payload.trimmed();
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const QStringList lines = payload.trimmed().split(QChar('\n'));
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if (lines.isEmpty() || lines.constFirst().trimmed() != QStringLiteral("qon-crypto: 2")) {
345+
return envelope;
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}
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QHash<QString, QString> metadata;
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int cipherTextLine = -1;
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for (int i = 0; i < lines.count(); ++i) {
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const QString line = lines.at(i).trimmed();
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if (line.isEmpty()) {
353+
cipherTextLine = i + 1;
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break;
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}
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const int separatorIndex = line.indexOf(QChar(':'));
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if (separatorIndex <= 0) {
359+
return envelope;
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}
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metadata.insert(line.left(separatorIndex).trimmed(),
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line.mid(separatorIndex + 1).trimmed());
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}
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if (cipherTextLine < 0 || cipherTextLine >= lines.count()) {
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return envelope;
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}
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bool iterationsOk = false;
371+
const size_t iterations =
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metadata.value(QStringLiteral("kdf-iterations")).toULongLong(&iterationsOk);
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const QString cipherText = lines.mid(cipherTextLine).join(QChar('\n')).trimmed();
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if (!iterationsOk ||
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metadata.value(QStringLiteral("qon-crypto")) != QString::number(NoteEncryptionVersion) ||
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metadata.value(QStringLiteral("kdf")) != NoteEncryptionKdf ||
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metadata.value(QStringLiteral("cipher")) != NoteEncryptionCipher ||
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metadata.value(QStringLiteral("salt")).isEmpty() ||
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metadata.value(QStringLiteral("nonce")).isEmpty() ||
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metadata.value(QStringLiteral("mac")).isEmpty() || cipherText.isEmpty()) {
382+
return envelope;
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}
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envelope.isV2 = true;
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envelope.cipherText = cipherText;
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envelope.kdf = metadata.value(QStringLiteral("kdf"));
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envelope.cipher = metadata.value(QStringLiteral("cipher"));
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envelope.salt = metadata.value(QStringLiteral("salt"));
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envelope.nonce = metadata.value(QStringLiteral("nonce"));
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envelope.mac = metadata.value(QStringLiteral("mac"));
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envelope.iterations = iterations;
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return envelope;
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}
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static QString buildNoteEncryptionEnvelope(const QString &cipherText, const QString &salt,
397+
const QString &nonce, const QString &mac) {
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return QStringLiteral(
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"qon-crypto: %1\n"
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"kdf: %2\n"
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"kdf-iterations: %3\n"
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"salt: %4\n"
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"cipher: %5\n"
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"nonce: %6\n"
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"mac: %7\n\n"
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"%8")
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.arg(QString::number(NoteEncryptionVersion), NoteEncryptionKdf,
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QString::number(NoteEncryptionKdfIterations), salt, NoteEncryptionCipher, nonce, mac,
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cipherText);
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}
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} // namespace
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322413
int Note::getId() const { return this->_id; }
@@ -4211,8 +4302,14 @@ QString Note::encryptNoteText() {
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// encrypt the text
42124303
BotanWrapper botanWrapper;
42134304
botanWrapper.setPassword(_cryptoPassword);
4214-
botanWrapper.setSalt(QStringLiteral(BOTAN_SALT));
4215-
encryptedText = botanWrapper.Encrypt(text);
4305+
const QString salt = BotanWrapper::randomBytesBase64(NoteEncryptionSaltBytes);
4306+
const QString nonce = BotanWrapper::randomBytesBase64(NoteEncryptionNonceBytes);
4307+
QString mac;
4308+
encryptedText =
4309+
botanWrapper.EncryptV2(text, salt, nonce, NoteEncryptionKdfIterations, &mac);
4310+
if (!encryptedText.isEmpty()) {
4311+
encryptedText = buildNoteEncryptionEnvelope(encryptedText, salt, nonce, mac);
4312+
}
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42174314
// SimpleCrypt *crypto = new
42184315
// SimpleCrypt(static_cast<quint64>(cryptoKey)); QString
@@ -4292,27 +4389,7 @@ bool Note::canDecryptNoteText() const {
42924389
return false;
42934390
}
42944391

4295-
// check if we have an external decryption method
4296-
QString decryptedNoteText =
4297-
ScriptingService::instance()->callEncryptionHook(encryptedNoteText, _cryptoPassword, true);
4298-
4299-
// check if a hook changed the text
4300-
if (decryptedNoteText.isEmpty()) {
4301-
// decrypt the note text with Botan
4302-
BotanWrapper botanWrapper;
4303-
botanWrapper.setPassword(_cryptoPassword);
4304-
botanWrapper.setSalt(QStringLiteral(BOTAN_SALT));
4305-
decryptedNoteText = botanWrapper.Decrypt(encryptedNoteText);
4306-
4307-
// fallback to SimpleCrypt
4308-
if (decryptedNoteText.isEmpty()) {
4309-
auto *crypto = new SimpleCrypt(static_cast<quint64>(_cryptoKey));
4310-
decryptedNoteText = crypto->decryptToString(encryptedNoteText);
4311-
delete crypto;
4312-
}
4313-
}
4314-
4315-
return !decryptedNoteText.isEmpty();
4392+
return !decryptEncryptedNoteText(encryptedNoteText).isEmpty();
43164393
}
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43184395
/**
@@ -4354,24 +4431,7 @@ QString Note::getDecryptedNoteText(
43544431
const QString &encryptedNoteText) const { // check if we have an external decryption method
43554432
QString noteText = getNoteText();
43564433

4357-
QString decryptedNoteText =
4358-
ScriptingService::instance()->callEncryptionHook(encryptedNoteText, _cryptoPassword, true);
4359-
4360-
// Check if a hook changed the text
4361-
if (decryptedNoteText.isEmpty()) {
4362-
// Decrypt the note text
4363-
BotanWrapper botanWrapper;
4364-
botanWrapper.setPassword(_cryptoPassword);
4365-
botanWrapper.setSalt(QStringLiteral(BOTAN_SALT));
4366-
decryptedNoteText = botanWrapper.Decrypt(encryptedNoteText);
4367-
4368-
// Fallback to SimpleCrypt
4369-
if (decryptedNoteText.isEmpty()) {
4370-
auto *crypto = new SimpleCrypt(static_cast<quint64>(_cryptoKey));
4371-
decryptedNoteText = crypto->decryptToString(encryptedNoteText);
4372-
delete crypto;
4373-
}
4374-
}
4434+
const QString decryptedNoteText = decryptEncryptedNoteText(encryptedNoteText);
43754435

43764436
if (decryptedNoteText.isEmpty()) {
43774437
return noteText;
@@ -4385,6 +4445,37 @@ QString Note::getDecryptedNoteText(
43854445
return noteText;
43864446
}
43874447

4448+
QString Note::decryptEncryptedNoteText(const QString &encryptedNoteText) const {
4449+
QString decryptedNoteText =
4450+
ScriptingService::instance()->callEncryptionHook(encryptedNoteText, _cryptoPassword, true);
4451+
4452+
if (!decryptedNoteText.isEmpty()) {
4453+
return decryptedNoteText;
4454+
}
4455+
4456+
const NoteEncryptionEnvelope envelope = parseNoteEncryptionEnvelope(encryptedNoteText);
4457+
BotanWrapper botanWrapper;
4458+
botanWrapper.setPassword(_cryptoPassword);
4459+
4460+
if (envelope.isV2) {
4461+
return botanWrapper.DecryptV2(envelope.cipherText, envelope.salt, envelope.nonce,
4462+
envelope.mac, envelope.iterations);
4463+
}
4464+
4465+
botanWrapper.setSalt(QStringLiteral(BOTAN_SALT));
4466+
decryptedNoteText = botanWrapper.Decrypt(encryptedNoteText);
4467+
4468+
if (!decryptedNoteText.isEmpty()) {
4469+
return decryptedNoteText;
4470+
}
4471+
4472+
auto *crypto = new SimpleCrypt(static_cast<quint64>(_cryptoKey));
4473+
decryptedNoteText = crypto->decryptToString(encryptedNoteText);
4474+
delete crypto;
4475+
4476+
return decryptedNoteText;
4477+
}
4478+
43884479
/**
43894480
* Expire crypto keys in the database after 10min
43904481
*/

‎src/entities/note.h‎

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Original file line numberDiff line numberDiff line change
@@ -427,6 +427,7 @@ class Note {
427427
const QString &connectionName = QStringLiteral("memory"));
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429429
[[nodiscard]] QString getDecryptedNoteText(const QString &encryptedNoteText) const;
430+
[[nodiscard]] QString decryptEncryptedNoteText(const QString &encryptedNoteText) const;
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431432
static QString parseEncryptedNoteText(const QString &noteText);
432433
static bool isEncryptedTextBegin(const QString &text);

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