--- a/ui/downloader.cpp	Tue Mar 11 19:00:35 2014 +0100
+++ b/ui/downloader.cpp	Wed Mar 12 16:15:52 2014 +0100
@@ -4,13 +4,30 @@
 #define DOWNLOAD_SERVER "https://www.intevation.de"
 #endif
 
-#ifdef Q_OS_WIN
-#endif
-
 #include <QFile>
 #include <QDir>
 #include <QDebug>
 #include <QStandardPaths>
+#include <QUuid>
+#include <QApplication>
+
+#include <polarssl/net.h>
+#include <polarssl/ssl.h>
+#include <polarssl/entropy.h>
+#include <polarssl/ctr_drbg.h>
+#include <polarssl/error.h>
+#include <polarssl/certs.h>
+
+#define MAX_SW_SIZE 10485760
+#define MAX_LIST_SIZE 1048576
+
+QString getErrorMsg(int ret)
+{
+    char errbuf[255];
+    polarssl_strerror(ret, errbuf, 255);
+    errbuf[254] = '\0'; /* Just to be sure */
+    return QString::fromLatin1(errbuf);
+}
 
 Downloader::Downloader(QObject* parent, const QString& url,
                        const QByteArray& certificate,
@@ -18,15 +35,89 @@
                        const QDateTime& newestList):
     QThread(parent),
     mUrl(url),
+    mPinnedCert(certificate),
     mLastModSW(newestSW),
-    mLastModList(newestList)
+    mLastModList(newestList),
+    mErrorState(NoError),
+    mInitialized(false),
+    mServerFD(-1)
 {
+    int ret = -1;
+
+    memset(&mSSL, 0, sizeof(ssl_context));
+
     if (certificate.isEmpty()) {
         QFile certResource(":certs/kolab.org");
         certResource.open(QFile::ReadOnly);
-        mCert = certResource.readAll();
+        mPinnedCert = certResource.readAll();
         certResource.close();
     }
+
+    ret = init();
+    if (ret == 0) {
+        mInitialized = true;
+    } else {
+        qDebug() << "Initialization error: " + getErrorMsg(ret);
+    }
+}
+
+int Downloader::init()
+{
+    int ret = -1;
+    QUuid uuid = QUuid::createUuid();
+    QString personalString = QApplication::applicationName() + uuid.toString();
+    QByteArray personalBa = personalString.toLocal8Bit();
+
+    x509_crt_init(&mX509PinnedCert);
+    entropy_init(&mEntropy);
+
+    ret = ssl_init(&mSSL);
+    if (ret != 0) {
+        /* The only documented error is malloc failed */
+        mErrorState = ErrUnknown;
+        return ret;
+    }
+
+    /*
+     * Initialize random generator.
+     * Personalisation string, does not need to be random but
+     * should be unique according to documentation.
+     *
+     * the ctr_drbg structure does not need to be freed explicitly.
+     */
+    ret = ctr_drbg_init(&mCtr_drbg, entropy_func, &mEntropy,
+                        (const unsigned char*) personalBa.constData(),
+                        personalBa.size());
+    if (ret != 0) {
+        ssl_free(&mSSL);
+        mErrorState = ErrUnknown;
+        return ret;
+    }
+
+    ret = x509_crt_parse(&mX509PinnedCert,
+                         (const unsigned char*) mPinnedCert.constData(),
+                         mPinnedCert.size());
+    if (ret != 0){
+        ssl_free(&mSSL);
+        mErrorState = InvalidPinnedCertificate;
+        return ret;
+    }
+
+    ssl_set_endpoint(&mSSL, SSL_IS_CLIENT);
+    ssl_set_authmode(&mSSL, SSL_VERIFY_OPTIONAL);
+    ssl_set_ca_chain(&mSSL, &mX509PinnedCert, NULL, NULL);
+    ssl_set_renegotiation(&mSSL, SSL_RENEGOTIATION_DISABLED);
+    ssl_set_rng(&mSSL, ctr_drbg_random, &mCtr_drbg);
+
+    return 0;
+}
+
+Downloader::~Downloader() {
+    x509_crt_free(&mX509PinnedCert);
+    entropy_free(&mEntropy);
+    if (mInitialized) {
+        ssl_free(&mSSL);
+    }
 }
 
 QString Downloader::getDataDirectory()
@@ -49,3 +140,120 @@
     }
     return cDir.absolutePath();
 }
+
+int Downloader::establishSSLConnection() {
+    int ret = -1;
+    const x509_crt *peerCert;
+
+    mErrorState = ErrUnknown;
+
+    if (mServerFD == -1) {
+        return -1;
+    }
+
+    ssl_set_bio(&mSSL, net_recv, &mServerFD,
+                       net_send, &mServerFD);
+
+    while ((ret = ssl_handshake(&mSSL)) != 0) {
+        if (ret != POLARSSL_ERR_NET_WANT_READ &&
+                ret != POLARSSL_ERR_NET_WANT_WRITE) {
+            qDebug() << "SSL Handshake failed: "
+                 << getErrorMsg(ret);
+            return ret;
+        }
+    }
+
+    ret = ssl_get_verify_result(&mSSL);
+
+    if (ret != 0 ) {
+
+        if( ( ret & BADCERT_EXPIRED ) != 0 )
+            qDebug() << "server certificate has expired";
+
+        if( ( ret & BADCERT_REVOKED ) != 0 )
+            qDebug() << "server certificate has been revoked";
+
+        if( ( ret & BADCERT_CN_MISMATCH ) != 0 )
+            qDebug() << "CN mismatch";
+
+        if( ( ret & BADCERT_NOT_TRUSTED ) != 0 )
+            qDebug() << "self-signed or not signed by a trusted CA";
+
+#ifdef RELEASE_BUILD
+        return -1;
+#endif
+    }
+
+    peerCert = ssl_get_peer_cert(&mSSL);
+
+    if (!peerCert) {
+        mErrorState = InvalidCertificate;
+        qDebug() << "Failed to get peer cert";
+        return -1;
+    }
+
+    if (peerCert->raw.len == 0 ||
+        peerCert->raw.len != mX509PinnedCert.raw.len) {
+        mErrorState = InvalidCertificate;
+        qDebug() << "Certificate length mismatch";
+        return -1;
+    }
+
+    /* You can never be sure what those c++ operators do..
+    if (mPinnedCert != QByteArray::fromRawData(
+                (const char*) peerCert->raw.p,
+            peerCert->raw.len)) {
+        qDebug() << "Certificate content mismatch";
+    }
+    */
+
+    for (unsigned int i = 0; i < peerCert->raw.len; i++) {
+        if (peerCert->raw.p[i] != mX509PinnedCert.raw.p[i]) {
+            qDebug() << "Certificate content mismatch";
+            mErrorState = InvalidCertificate;
+            return -1;
+        }
+    }
+    mErrorState = NoError;
+    return 0;
+}
+
+
+void Downloader::run() {
+    int ret;
+
+    if (!mInitialized) {
+        emit error(tr("Failed to initialize SSL Module."), ErrUnknown);
+        return;
+    }
+
+    ret = net_connect(&mServerFD, mUrl.host().toLatin1().constData(),
+            mUrl.port(443));
+    if (ret != 0) {
+        mErrorState = NoConnection;
+        emit error(tr("Failed to connect to %1.").arg(mUrl.host()),
+                mErrorState);
+        return;
+    }
+
+    emit progress(tr("Connected"), 1, -1);
+
+    ret = establishSSLConnection();
+    if (ret != 0) {
+        qDebug() << "SSL conncetion failed: " << getErrorMsg(ret);
+        emit error(tr("Failed to connect to %1.").arg(mUrl.host()),
+                mErrorState);
+        return;
+    }
+
+    qDebug() << "Connected to: " << mUrl.host();
+    // TODO
+
+    emit progress(tr("Closing"), 1, -1);
+    ssl_close_notify (&mSSL);
+
+    if (mServerFD != -1) {
+        net_close(mServerFD);
+        mServerFD = -1;
+    }
+}