crypto: introduce new module for handling TLS sessions

Introduce a QCryptoTLSSession object that will encapsulate
all the code for setting up and using a client/sever TLS
session. This isolates the code which depends on the gnutls
library, avoiding #ifdefs in the rest of the codebase, as
well as facilitating any possible future port to other TLS
libraries, if desired. It makes use of the previously
defined QCryptoTLSCreds object to access credentials to
use with the session. It also includes further unit tests
to validate the correctness of the TLS session handshake
and certificate validation. This is functionally equivalent
to the current TLS session handling code embedded in the
VNC server, and will obsolete it.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>

1 files changed, 535 insertions, 0 deletions

diff --git a/tests/test-crypto-tlssession.c b/tests/test-crypto-tlssession.c
new file mode 100644
index 0000000..4524128
--- /dev/null
+++ b/tests/test-crypto-tlssession.c
@@ -0,0 +1,535 @@
+/*
+ * Copyright (C) 2015 Red Hat, Inc.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library.  If not, see
+ * <http://www.gnu.org/licenses/>.
+ *
+ * Author: Daniel P. Berrange <berrange@redhat.com>
+ */
+
+#include <stdlib.h>
+#include <fcntl.h>
+
+#include "config-host.h"
+#include "crypto-tls-x509-helpers.h"
+#include "crypto/tlscredsx509.h"
+#include "crypto/tlssession.h"
+#include "qom/object_interfaces.h"
+#include "qemu/sockets.h"
+#include "qemu/acl.h"
+
+#ifdef QCRYPTO_HAVE_TLS_TEST_SUPPORT
+
+#define WORKDIR "tests/test-crypto-tlssession-work/"
+#define KEYFILE WORKDIR "key-ctx.pem"
+
+struct QCryptoTLSSessionTestData {
+    const char *servercacrt;
+    const char *clientcacrt;
+    const char *servercrt;
+    const char *clientcrt;
+    bool expectServerFail;
+    bool expectClientFail;
+    const char *hostname;
+    const char *const *wildcards;
+};
+
+
+static ssize_t testWrite(const char *buf, size_t len, void *opaque)
+{
+    int *fd = opaque;
+
+    return write(*fd, buf, len);
+}
+
+static ssize_t testRead(char *buf, size_t len, void *opaque)
+{
+    int *fd = opaque;
+
+    return read(*fd, buf, len);
+}
+
+static QCryptoTLSCreds *test_tls_creds_create(QCryptoTLSCredsEndpoint endpoint,
+                                              const char *certdir,
+                                              Error **errp)
+{
+    Error *err = NULL;
+    Object *parent = object_get_objects_root();
+    Object *creds = object_new_with_props(
+        TYPE_QCRYPTO_TLS_CREDS_X509,
+        parent,
+        (endpoint == QCRYPTO_TLS_CREDS_ENDPOINT_SERVER ?
+         "testtlscredsserver" : "testtlscredsclient"),
+        &err,
+        "endpoint", (endpoint == QCRYPTO_TLS_CREDS_ENDPOINT_SERVER ?
+                     "server" : "client"),
+        "dir", certdir,
+        "verify-peer", "yes",
+        /* We skip initial sanity checks here because we
+         * want to make sure that problems are being
+         * detected at the TLS session validation stage,
+         * and the test-crypto-tlscreds test already
+         * validate the sanity check code.
+         */
+        "sanity-check", "no",
+        NULL
+        );
+
+    if (err) {
+        error_propagate(errp, err);
+        return NULL;
+    }
+    return QCRYPTO_TLS_CREDS(creds);
+}
+
+
+/*
+ * This tests validation checking of peer certificates
+ *
+ * This is replicating the checks that are done for an
+ * active TLS session after handshake completes. To
+ * simulate that we create our TLS contexts, skipping
+ * sanity checks. We then get a socketpair, and
+ * initiate a TLS session across them. Finally do
+ * do actual cert validation tests
+ */
+static void test_crypto_tls_session(const void *opaque)
+{
+    struct QCryptoTLSSessionTestData *data =
+        (struct QCryptoTLSSessionTestData *)opaque;
+    QCryptoTLSCreds *clientCreds;
+    QCryptoTLSCreds *serverCreds;
+    QCryptoTLSSession *clientSess = NULL;
+    QCryptoTLSSession *serverSess = NULL;
+    qemu_acl *acl;
+    const char * const *wildcards;
+    int channel[2];
+    bool clientShake = false;
+    bool serverShake = false;
+    Error *err = NULL;
+    int ret;
+
+    /* We'll use this for our fake client-server connection */
+    ret = socketpair(AF_UNIX, SOCK_STREAM, 0, channel);
+    g_assert(ret == 0);
+
+    /*
+     * We have an evil loop to do the handshake in a single
+     * thread, so we need these non-blocking to avoid deadlock
+     * of ourselves
+     */
+    qemu_set_nonblock(channel[0]);
+    qemu_set_nonblock(channel[1]);
+
+#define CLIENT_CERT_DIR "tests/test-crypto-tlssession-client/"
+#define SERVER_CERT_DIR "tests/test-crypto-tlssession-server/"
+    mkdir(CLIENT_CERT_DIR, 0700);
+    mkdir(SERVER_CERT_DIR, 0700);
+
+    unlink(SERVER_CERT_DIR QCRYPTO_TLS_CREDS_X509_CA_CERT);
+    unlink(SERVER_CERT_DIR QCRYPTO_TLS_CREDS_X509_SERVER_CERT);
+    unlink(SERVER_CERT_DIR QCRYPTO_TLS_CREDS_X509_SERVER_KEY);
+
+    unlink(CLIENT_CERT_DIR QCRYPTO_TLS_CREDS_X509_CA_CERT);
+    unlink(CLIENT_CERT_DIR QCRYPTO_TLS_CREDS_X509_CLIENT_CERT);
+    unlink(CLIENT_CERT_DIR QCRYPTO_TLS_CREDS_X509_CLIENT_KEY);
+
+    g_assert(link(data->servercacrt,
+                  SERVER_CERT_DIR QCRYPTO_TLS_CREDS_X509_CA_CERT) == 0);
+    g_assert(link(data->servercrt,
+                  SERVER_CERT_DIR QCRYPTO_TLS_CREDS_X509_SERVER_CERT) == 0);
+    g_assert(link(KEYFILE,
+                  SERVER_CERT_DIR QCRYPTO_TLS_CREDS_X509_SERVER_KEY) == 0);
+
+    g_assert(link(data->clientcacrt,
+                  CLIENT_CERT_DIR QCRYPTO_TLS_CREDS_X509_CA_CERT) == 0);
+    g_assert(link(data->clientcrt,
+                  CLIENT_CERT_DIR QCRYPTO_TLS_CREDS_X509_CLIENT_CERT) == 0);
+    g_assert(link(KEYFILE,
+                  CLIENT_CERT_DIR QCRYPTO_TLS_CREDS_X509_CLIENT_KEY) == 0);
+
+    clientCreds = test_tls_creds_create(
+        QCRYPTO_TLS_CREDS_ENDPOINT_CLIENT,
+        CLIENT_CERT_DIR,
+        &err);
+    g_assert(clientCreds != NULL);
+
+    serverCreds = test_tls_creds_create(
+        QCRYPTO_TLS_CREDS_ENDPOINT_SERVER,
+        SERVER_CERT_DIR,
+        &err);
+    g_assert(serverCreds != NULL);
+
+    acl = qemu_acl_init("tlssessionacl");
+    qemu_acl_reset(acl);
+    wildcards = data->wildcards;
+    while (wildcards && *wildcards) {
+        qemu_acl_append(acl, 0, *wildcards);
+        wildcards++;
+    }
+
+    /* Now the real part of the test, setup the sessions */
+    clientSess = qcrypto_tls_session_new(
+        clientCreds, data->hostname, NULL,
+        QCRYPTO_TLS_CREDS_ENDPOINT_CLIENT, &err);
+    serverSess = qcrypto_tls_session_new(
+        serverCreds, NULL,
+        data->wildcards ? "tlssessionacl" : NULL,
+        QCRYPTO_TLS_CREDS_ENDPOINT_SERVER, &err);
+
+    g_assert(clientSess != NULL);
+    g_assert(serverSess != NULL);
+
+    /* For handshake to work, we need to set the I/O callbacks
+     * to read/write over the socketpair
+     */
+    qcrypto_tls_session_set_callbacks(serverSess,
+                                      testWrite, testRead,
+                                      &channel[0]);
+    qcrypto_tls_session_set_callbacks(clientSess,
+                                      testWrite, testRead,
+                                      &channel[1]);
+
+    /*
+     * Finally we loop around & around doing handshake on each
+     * session until we get an error, or the handshake completes.
+     * This relies on the socketpair being nonblocking to avoid
+     * deadlocking ourselves upon handshake
+     */
+    do {
+        int rv;
+        if (!serverShake) {
+            rv = qcrypto_tls_session_handshake(serverSess,
+                                               &err);
+            g_assert(rv >= 0);
+            if (qcrypto_tls_session_get_handshake_status(serverSess) ==
+                QCRYPTO_TLS_HANDSHAKE_COMPLETE) {
+                serverShake = true;
+            }
+        }
+        if (!clientShake) {
+            rv = qcrypto_tls_session_handshake(clientSess,
+                                               &err);
+            g_assert(rv >= 0);
+            if (qcrypto_tls_session_get_handshake_status(clientSess) ==
+                QCRYPTO_TLS_HANDSHAKE_COMPLETE) {
+                clientShake = true;
+            }
+        }
+    } while (!clientShake && !serverShake);
+
+
+    /* Finally make sure the server validation does what
+     * we were expecting
+     */
+    if (qcrypto_tls_session_check_credentials(serverSess, &err) < 0) {
+        g_assert(data->expectServerFail);
+        error_free(err);
+        err = NULL;
+    } else {
+        g_assert(!data->expectServerFail);
+    }
+
+    /*
+     * And the same for the client validation check
+     */
+    if (qcrypto_tls_session_check_credentials(clientSess, &err) < 0) {
+        g_assert(data->expectClientFail);
+        error_free(err);
+        err = NULL;
+    } else {
+        g_assert(!data->expectClientFail);
+    }
+
+    unlink(SERVER_CERT_DIR QCRYPTO_TLS_CREDS_X509_CA_CERT);
+    unlink(SERVER_CERT_DIR QCRYPTO_TLS_CREDS_X509_SERVER_CERT);
+    unlink(SERVER_CERT_DIR QCRYPTO_TLS_CREDS_X509_SERVER_KEY);
+
+    unlink(CLIENT_CERT_DIR QCRYPTO_TLS_CREDS_X509_CA_CERT);
+    unlink(CLIENT_CERT_DIR QCRYPTO_TLS_CREDS_X509_CLIENT_CERT);
+    unlink(CLIENT_CERT_DIR QCRYPTO_TLS_CREDS_X509_CLIENT_KEY);
+
+    rmdir(CLIENT_CERT_DIR);
+    rmdir(SERVER_CERT_DIR);
+
+    object_unparent(OBJECT(serverCreds));
+    object_unparent(OBJECT(clientCreds));
+
+    qcrypto_tls_session_free(serverSess);
+    qcrypto_tls_session_free(clientSess);
+
+    close(channel[0]);
+    close(channel[1]);
+}
+
+
+int main(int argc, char **argv)
+{
+    int ret;
+
+    module_call_init(MODULE_INIT_QOM);
+    g_test_init(&argc, &argv, NULL);
+    setenv("GNUTLS_FORCE_FIPS_MODE", "2", 1);
+
+    mkdir(WORKDIR, 0700);
+
+    test_tls_init(KEYFILE);
+
+# define TEST_SESS_REG(name, caCrt,                                     \
+                       serverCrt, clientCrt,                            \
+                       expectServerFail, expectClientFail,              \
+                       hostname, wildcards)                             \
+    struct QCryptoTLSSessionTestData name = {                           \
+        caCrt, caCrt, serverCrt, clientCrt,                             \
+        expectServerFail, expectClientFail,                             \
+        hostname, wildcards                                             \
+    };                                                                  \
+    g_test_add_data_func("/qcrypto/tlssession/" # name,                 \
+                         &name, test_crypto_tls_session);               \
+
+
+# define TEST_SESS_REG_EXT(name, serverCaCrt, clientCaCrt,              \
+                           serverCrt, clientCrt,                        \
+                           expectServerFail, expectClientFail,          \
+                           hostname, wildcards)                         \
+    struct QCryptoTLSSessionTestData name = {                           \
+        serverCaCrt, clientCaCrt, serverCrt, clientCrt,                 \
+        expectServerFail, expectClientFail,                             \
+        hostname, wildcards                                             \
+    };                                                                  \
+    g_test_add_data_func("/qcrypto/tlssession/" # name,                 \
+                         &name, test_crypto_tls_session);               \
+
+    /* A perfect CA, perfect client & perfect server */
+
+    /* Basic:CA:critical */
+    TLS_ROOT_REQ(cacertreq,
+                 "UK", "qemu CA", NULL, NULL, NULL, NULL,
+                 true, true, true,
+                 true, true, GNUTLS_KEY_KEY_CERT_SIGN,
+                 false, false, NULL, NULL,
+                 0, 0);
+
+    TLS_ROOT_REQ(altcacertreq,
+                 "UK", "qemu CA 1", NULL, NULL, NULL, NULL,
+                 true, true, true,
+                 false, false, 0,
+                 false, false, NULL, NULL,
+                 0, 0);
+
+    TLS_CERT_REQ(servercertreq, cacertreq,
+                 "UK", "qemu.org", NULL, NULL, NULL, NULL,
+                 true, true, false,
+                 true, true,
+                 GNUTLS_KEY_DIGITAL_SIGNATURE | GNUTLS_KEY_KEY_ENCIPHERMENT,
+                 true, true, GNUTLS_KP_TLS_WWW_SERVER, NULL,
+                 0, 0);
+    TLS_CERT_REQ(clientcertreq, cacertreq,
+                 "UK", "qemu", NULL, NULL, NULL, NULL,
+                 true, true, false,
+                 true, true,
+                 GNUTLS_KEY_DIGITAL_SIGNATURE | GNUTLS_KEY_KEY_ENCIPHERMENT,
+                 true, true, GNUTLS_KP_TLS_WWW_CLIENT, NULL,
+                 0, 0);
+
+    TLS_CERT_REQ(clientcertaltreq, altcacertreq,
+                 "UK", "qemu", NULL, NULL, NULL, NULL,
+                 true, true, false,
+                 true, true,
+                 GNUTLS_KEY_DIGITAL_SIGNATURE | GNUTLS_KEY_KEY_ENCIPHERMENT,
+                 true, true, GNUTLS_KP_TLS_WWW_CLIENT, NULL,
+                 0, 0);
+
+    TEST_SESS_REG(basicca, cacertreq.filename,
+                  servercertreq.filename, clientcertreq.filename,
+                  false, false, "qemu.org", NULL);
+    TEST_SESS_REG_EXT(differentca, cacertreq.filename,
+                      altcacertreq.filename, servercertreq.filename,
+                      clientcertaltreq.filename, true, true, "qemu.org", NULL);
+
+
+    /* When an altname is set, the CN is ignored, so it must be duplicated
+     * as an altname for it to match */
+    TLS_CERT_REQ(servercertalt1req, cacertreq,
+                 "UK", "qemu.org", "www.qemu.org", "qemu.org",
+                 "192.168.122.1", "fec0::dead:beaf",
+                 true, true, false,
+                 true, true,
+                 GNUTLS_KEY_DIGITAL_SIGNATURE | GNUTLS_KEY_KEY_ENCIPHERMENT,
+                 true, true, GNUTLS_KP_TLS_WWW_SERVER, NULL,
+                 0, 0);
+    /* This intentionally doesn't replicate */
+    TLS_CERT_REQ(servercertalt2req, cacertreq,
+                 "UK", "qemu.org", "www.qemu.org", "wiki.qemu.org",
+                 "192.168.122.1", "fec0::dead:beaf",
+                 true, true, false,
+                 true, true,
+                 GNUTLS_KEY_DIGITAL_SIGNATURE | GNUTLS_KEY_KEY_ENCIPHERMENT,
+                 true, true, GNUTLS_KP_TLS_WWW_SERVER, NULL,
+                 0, 0);
+
+    TEST_SESS_REG(altname1, cacertreq.filename,
+                  servercertalt1req.filename, clientcertreq.filename,
+                  false, false, "qemu.org", NULL);
+    TEST_SESS_REG(altname2, cacertreq.filename,
+                  servercertalt1req.filename, clientcertreq.filename,
+                  false, false, "www.qemu.org", NULL);
+    TEST_SESS_REG(altname3, cacertreq.filename,
+                  servercertalt1req.filename, clientcertreq.filename,
+                  false, true, "wiki.qemu.org", NULL);
+
+    TEST_SESS_REG(altname4, cacertreq.filename,
+                  servercertalt2req.filename, clientcertreq.filename,
+                  false, true, "qemu.org", NULL);
+    TEST_SESS_REG(altname5, cacertreq.filename,
+                  servercertalt2req.filename, clientcertreq.filename,
+                  false, false, "www.qemu.org", NULL);
+    TEST_SESS_REG(altname6, cacertreq.filename,
+                  servercertalt2req.filename, clientcertreq.filename,
+                  false, false, "wiki.qemu.org", NULL);
+
+    const char *const wildcards1[] = {
+        "C=UK,CN=dogfood",
+        NULL,
+    };
+    const char *const wildcards2[] = {
+        "C=UK,CN=qemu",
+        NULL,
+    };
+    const char *const wildcards3[] = {
+        "C=UK,CN=dogfood",
+        "C=UK,CN=qemu",
+        NULL,
+    };
+    const char *const wildcards4[] = {
+        "C=UK,CN=qemustuff",
+        NULL,
+    };
+    const char *const wildcards5[] = {
+        "C=UK,CN=qemu*",
+        NULL,
+    };
+    const char *const wildcards6[] = {
+        "C=UK,CN=*emu*",
+        NULL,
+    };
+
+    TEST_SESS_REG(wildcard1, cacertreq.filename,
+                  servercertreq.filename, clientcertreq.filename,
+                  true, false, "qemu.org", wildcards1);
+    TEST_SESS_REG(wildcard2, cacertreq.filename,
+                  servercertreq.filename, clientcertreq.filename,
+                  false, false, "qemu.org", wildcards2);
+    TEST_SESS_REG(wildcard3, cacertreq.filename,
+                  servercertreq.filename, clientcertreq.filename,
+                  false, false, "qemu.org", wildcards3);
+    TEST_SESS_REG(wildcard4, cacertreq.filename,
+                  servercertreq.filename, clientcertreq.filename,
+                  true, false, "qemu.org", wildcards4);
+    TEST_SESS_REG(wildcard5, cacertreq.filename,
+                  servercertreq.filename, clientcertreq.filename,
+                  false, false, "qemu.org", wildcards5);
+    TEST_SESS_REG(wildcard6, cacertreq.filename,
+                  servercertreq.filename, clientcertreq.filename,
+                  false, false, "qemu.org", wildcards6);
+
+    TLS_ROOT_REQ(cacertrootreq,
+                 "UK", "qemu root", NULL, NULL, NULL, NULL,
+                 true, true, true,
+                 true, true, GNUTLS_KEY_KEY_CERT_SIGN,
+                 false, false, NULL, NULL,
+                 0, 0);
+    TLS_CERT_REQ(cacertlevel1areq, cacertrootreq,
+                 "UK", "qemu level 1a", NULL, NULL, NULL, NULL,
+                 true, true, true,
+                 true, true, GNUTLS_KEY_KEY_CERT_SIGN,
+                 false, false, NULL, NULL,
+                 0, 0);
+    TLS_CERT_REQ(cacertlevel1breq, cacertrootreq,
+                 "UK", "qemu level 1b", NULL, NULL, NULL, NULL,
+                 true, true, true,
+                 true, true, GNUTLS_KEY_KEY_CERT_SIGN,
+                 false, false, NULL, NULL,
+                 0, 0);
+    TLS_CERT_REQ(cacertlevel2areq, cacertlevel1areq,
+                 "UK", "qemu level 2a", NULL, NULL, NULL, NULL,
+                 true, true, true,
+                 true, true, GNUTLS_KEY_KEY_CERT_SIGN,
+                 false, false, NULL, NULL,
+                 0, 0);
+    TLS_CERT_REQ(servercertlevel3areq, cacertlevel2areq,
+                 "UK", "qemu.org", NULL, NULL, NULL, NULL,
+                 true, true, false,
+                 true, true,
+                 GNUTLS_KEY_DIGITAL_SIGNATURE | GNUTLS_KEY_KEY_ENCIPHERMENT,
+                 true, true, GNUTLS_KP_TLS_WWW_SERVER, NULL,
+                 0, 0);
+    TLS_CERT_REQ(clientcertlevel2breq, cacertlevel1breq,
+                 "UK", "qemu client level 2b", NULL, NULL, NULL, NULL,
+                 true, true, false,
+                 true, true,
+                 GNUTLS_KEY_DIGITAL_SIGNATURE | GNUTLS_KEY_KEY_ENCIPHERMENT,
+                 true, true, GNUTLS_KP_TLS_WWW_CLIENT, NULL,
+                 0, 0);
+
+    gnutls_x509_crt_t certchain[] = {
+        cacertrootreq.crt,
+        cacertlevel1areq.crt,
+        cacertlevel1breq.crt,
+        cacertlevel2areq.crt,
+    };
+
+    test_tls_write_cert_chain(WORKDIR "cacertchain-sess.pem",
+                              certchain,
+                              G_N_ELEMENTS(certchain));
+
+    TEST_SESS_REG(cachain, WORKDIR "cacertchain-sess.pem",
+                  servercertlevel3areq.filename, clientcertlevel2breq.filename,
+                  false, false, "qemu.org", NULL);
+
+    ret = g_test_run();
+
+    test_tls_discard_cert(&clientcertreq);
+    test_tls_discard_cert(&clientcertaltreq);
+
+    test_tls_discard_cert(&servercertreq);
+    test_tls_discard_cert(&servercertalt1req);
+    test_tls_discard_cert(&servercertalt2req);
+
+    test_tls_discard_cert(&cacertreq);
+    test_tls_discard_cert(&altcacertreq);
+
+    test_tls_discard_cert(&cacertrootreq);
+    test_tls_discard_cert(&cacertlevel1areq);
+    test_tls_discard_cert(&cacertlevel1breq);
+    test_tls_discard_cert(&cacertlevel2areq);
+    test_tls_discard_cert(&servercertlevel3areq);
+    test_tls_discard_cert(&clientcertlevel2breq);
+    unlink(WORKDIR "cacertchain-sess.pem");
+
+    test_tls_cleanup(KEYFILE);
+    rmdir(WORKDIR);
+
+    return ret == 0 ? EXIT_SUCCESS : EXIT_FAILURE;
+}
+
+#else /* ! QCRYPTO_HAVE_TLS_TEST_SUPPORT */
+
+int
+main(void)
+{
+    return EXIT_SUCCESS;
+}
+
+#endif /* ! QCRYPTO_HAVE_TLS_TEST_SUPPORT */