Implement XEP-0448: Encryption for stateless file sharing parsing (#463)

https://xmpp.org/extensions/xep-0448.html

Co-authored-by: Jonah Brüchert <jbb@kaidan.im>

1 files changed, 157 insertions, 0 deletions

diff --git a/src/base/QXmppEncryptedFileSource.cpp b/src/base/QXmppEncryptedFileSource.cpp
new file mode 100644
index 00000000..d2c2b592
--- /dev/null
+++ b/src/base/QXmppEncryptedFileSource.cpp
@@ -0,0 +1,157 @@
+// SPDX-FileCopyrightText: 2022 Linus Jahn <lnj@kaidan.im>
+// SPDX-FileCopyrightText: 2022 Jonah Brüchert <jbb@kaidan.im>
+//
+// SPDX-License-Identifier: LGPL-2.1-or-later
+
+#include "QXmppConstants_p.h"
+#include "QXmppEncryptedFileSource_p.h"
+#include "QXmppHttpFileSource.h"
+
+#include <optional>
+
+#include <QDomElement>
+#include <QXmlStreamWriter>
+
+/// \cond
+static QString cipherToString(QXmppEncryptedFileSource::Cipher cipher)
+{
+    switch (cipher) {
+    case QXmppEncryptedFileSource::Aes128GcmNopadding:
+        return "urn:xmpp:ciphers:aes-128-gcm-nopadding:0";
+    case QXmppEncryptedFileSource::Aes256GcmNopadding:
+        return "urn:xmpp:ciphers:aes-256-gcm-nopadding:0";
+    case QXmppEncryptedFileSource::Aes256CbcPkcs7:
+        return "urn:xmpp:ciphers:aes-256-cbc-pkcs7:0";
+    }
+    Q_UNREACHABLE();
+}
+
+static std::optional<QXmppEncryptedFileSource::Cipher> cipherFromString(const QString &cipher)
+{
+    if (cipher == "urn:xmpp:ciphers:aes-128-gcm-nopadding:0") {
+        return QXmppEncryptedFileSource::Aes128GcmNopadding;
+    } else if (cipher == "urn:xmpp:ciphers:aes-256-gcm-nopadding:0") {
+        return QXmppEncryptedFileSource::Aes256GcmNopadding;
+    } else if (cipher == "urn:xmpp:ciphers:aes-256-cbc-pkcs7:0") {
+        return QXmppEncryptedFileSource::Aes256CbcPkcs7;
+    }
+    return {};
+}
+
+QXmppEncryptedFileSource::QXmppEncryptedFileSource() = default;
+
+QXmppEncryptedFileSource::Cipher QXmppEncryptedFileSource::cipher() const
+{
+    return m_cipher;
+}
+
+void QXmppEncryptedFileSource::setCipher(Cipher newCipher)
+{
+    m_cipher = newCipher;
+}
+
+const QByteArray &QXmppEncryptedFileSource::key() const
+{
+    return m_key;
+}
+
+void QXmppEncryptedFileSource::setKey(const QByteArray &newKey)
+{
+    m_key = newKey;
+}
+
+const QByteArray &QXmppEncryptedFileSource::iv() const
+{
+    return m_iv;
+}
+
+void QXmppEncryptedFileSource::setIv(const QByteArray &newIv)
+{
+    m_iv = newIv;
+}
+
+const QVector<QXmppHash> &QXmppEncryptedFileSource::hashes() const
+{
+    return m_hashes;
+}
+
+void QXmppEncryptedFileSource::setHashes(const QVector<QXmppHash> &newHashes)
+{
+    m_hashes = newHashes;
+}
+
+const QVector<QXmppHttpFileSource> &QXmppEncryptedFileSource::httpSources() const
+{
+    return m_httpSources;
+}
+
+void QXmppEncryptedFileSource::setHttpSources(const QVector<QXmppHttpFileSource> &newHttpSources)
+{
+    m_httpSources = newHttpSources;
+}
+
+bool QXmppEncryptedFileSource::parse(const QDomElement &el)
+{
+    QString cipher = el.attribute(QStringLiteral("cipher"));
+    if (auto parsedCipher = cipherFromString(cipher)) {
+        m_cipher = *parsedCipher;
+    } else {
+        return false;
+    }
+
+    auto keyEl = el.firstChildElement(QStringLiteral("key"));
+    if (keyEl.isNull()) {
+        return false;
+    }
+    m_key = QByteArray::fromBase64(keyEl.text().toUtf8());
+
+    auto ivEl = el.firstChildElement(QStringLiteral("iv"));
+    if (ivEl.isNull()) {
+        return false;
+    }
+    m_iv = QByteArray::fromBase64(ivEl.text().toUtf8());
+
+    for (auto childEl = el.firstChildElement(QStringLiteral("hash"));
+         !childEl.isNull();
+         childEl = childEl.nextSiblingElement(QStringLiteral("hash"))) {
+        QXmppHash hash;
+        if (!hash.parse(childEl)) {
+            return false;
+        }
+        m_hashes.push_back(std::move(hash));
+    }
+
+    auto sourcesEl = el.firstChildElement(QStringLiteral("sources"));
+    if (sourcesEl.isNull()) {
+        return false;
+    }
+    for (auto childEl = sourcesEl.firstChildElement(QStringLiteral("url-data"));
+         !childEl.isNull();
+         childEl = childEl.nextSiblingElement(QStringLiteral("url-data"))) {
+        QXmppHttpFileSource source;
+        source.parse(childEl);
+        m_httpSources.push_back(std::move(source));
+    }
+
+    return true;
+}
+
+void QXmppEncryptedFileSource::toXml(QXmlStreamWriter *writer) const
+{
+    writer->writeStartElement(QStringLiteral("encrypted"));
+    writer->writeDefaultNamespace(ns_esfs);
+    writer->writeAttribute(QStringLiteral("cipher"), cipherToString(m_cipher));
+    writer->writeTextElement(QStringLiteral("key"), m_key.toBase64());
+    writer->writeTextElement(QStringLiteral("iv"), m_iv.toBase64());
+    for (const auto &hash : m_hashes) {
+        hash.toXml(writer);
+    }
+    writer->writeStartElement(QStringLiteral("sources"));
+    writer->writeDefaultNamespace(ns_sfs);
+    for (const auto &source : m_httpSources) {
+        source.toXml(writer);
+    }
+    writer->writeEndElement();
+    writer->writeEndElement();
+}
+/// \endcond