Add regress tests for DTLS.

Test the operation of a DTLS client and server, with and without cookies,
using the default MTU and a specifically lowered MTU.

Further regress tests will be built on this to exercise other parts of the
DTLS code base (such as retransmission, fragmentation and reassembly).

2 files changed, 411 insertions, 0 deletions

diff --git a/src/regress/lib/libssl/dtls/Makefile b/src/regress/lib/libssl/dtls/Makefile
new file mode 100644
index 0000000000..5d25cde2ee
--- /dev/null
+++ b/src/regress/lib/libssl/dtls/Makefile
@@ -0,0 +1,18 @@
+#       $OpenBSD: Makefile,v 1.1 2020/10/14 15:49:14 jsing Exp $
+
+PROG=   dtlstest
+LDADD=  -lssl -lcrypto
+DPADD=  ${LIBSSL} ${LIBCRYPTO}
+WARNINGS=       Yes
+CFLAGS+=        -DLIBRESSL_INTERNAL -Werror
+
+REGRESS_TARGETS= \
+        regress-dtlstest
+
+regress-dtlstest: ${PROG}
+        ./dtlstest \
+            ${.CURDIR}/../../libssl/certs/server.pem \
+            ${.CURDIR}/../../libssl/certs/server.pem \
+            ${.CURDIR}/../../libssl/certs/ca.pem
+
+.include <bsd.regress.mk>
diff --git a/src/regress/lib/libssl/dtls/dtlstest.c b/src/regress/lib/libssl/dtls/dtlstest.c
new file mode 100644
index 0000000000..8cb4822b33
--- /dev/null
+++ b/src/regress/lib/libssl/dtls/dtlstest.c
@@ -0,0 +1,393 @@
+/* $OpenBSD: dtlstest.c,v 1.1 2020/10/14 15:49:14 jsing Exp $ */
+/*
+ * Copyright (c) 2020 Joel Sing <jsing@openbsd.org>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#include <netinet/in.h>
+#include <sys/limits.h>
+#include <sys/socket.h>
+
+#include <err.h>
+#include <poll.h>
+#include <unistd.h>
+
+#include <openssl/bio.h>
+#include <openssl/err.h>
+#include <openssl/ssl.h>
+
+const char *server_ca_file;
+const char *server_cert_file;
+const char *server_key_file;
+
+char dtls_cookie[32];
+
+static int
+datagram_pair(int *client_sock, int *server_sock,
+    struct sockaddr_in *server_sin)
+{
+        struct sockaddr_in sin;
+        socklen_t sock_len;
+        int cs = -1, ss = -1;
+
+        memset(&sin, 0, sizeof(sin));
+        sin.sin_family = AF_INET;
+        sin.sin_port = 0;
+        sin.sin_addr.s_addr = htonl(INADDR_LOOPBACK);
+
+        if ((ss = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP)) == -1)
+                err(1, "server socket");
+        if (bind(ss, (struct sockaddr *)&sin, sizeof(sin)) == -1)
+                err(1, "server bind");
+        sock_len = sizeof(sin);
+        if (getsockname(ss, (struct sockaddr *)&sin, &sock_len) == -1)
+                err(1, "server getsockname");
+
+        if ((cs = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP)) == -1)
+                err(1, "client socket");
+        if (connect(cs, (struct sockaddr *)&sin, sizeof(sin)) == -1)
+                err(1, "client connect");
+
+        *client_sock = cs;
+        *server_sock = ss;
+        memcpy(server_sin, &sin, sizeof(sin));
+
+        return 1;
+}
+
+static int
+poll_timeout(SSL *client, SSL *server)
+{
+        int client_timeout = 0, server_timeout = 0;
+        struct timeval timeout;
+
+        if (DTLSv1_get_timeout(client, &timeout))
+                client_timeout = timeout.tv_sec * 1000 + timeout.tv_usec / 1000;
+
+        if (DTLSv1_get_timeout(server, &timeout))
+                server_timeout = timeout.tv_sec * 1000 + timeout.tv_usec / 1000;
+
+        if (client_timeout > 0 && client_timeout < server_timeout)
+                return client_timeout;
+
+        return server_timeout;
+}
+
+static int
+dtls_cookie_generate(SSL *ssl, unsigned char *cookie,
+    unsigned int *cookie_len)
+{
+        arc4random_buf(dtls_cookie, sizeof(dtls_cookie));
+        memcpy(cookie, dtls_cookie, sizeof(dtls_cookie));
+        *cookie_len = sizeof(dtls_cookie);
+
+        return 1;
+}
+
+static int
+dtls_cookie_verify(SSL *ssl, const unsigned char *cookie,
+    unsigned int cookie_len)
+{
+        return cookie_len == sizeof(dtls_cookie) &&
+            memcmp(cookie, dtls_cookie, sizeof(dtls_cookie)) == 0;
+}
+
+static SSL *
+dtls_client(int sock, struct sockaddr_in *server_sin, long mtu)
+{
+        SSL_CTX *ssl_ctx = NULL;
+        SSL *ssl = NULL;
+        BIO *bio = NULL;
+
+        if ((bio = BIO_new_dgram(sock, BIO_NOCLOSE)) == NULL)
+                errx(1, "client bio");
+        if (!BIO_socket_nbio(sock, 1))
+                errx(1, "client nbio");
+        if (!BIO_ctrl_set_connected(bio, 1, server_sin))
+                errx(1, "client set connected");
+
+        if ((ssl_ctx = SSL_CTX_new(DTLS_method())) == NULL)
+                errx(1, "client context");
+        SSL_CTX_set_read_ahead(ssl_ctx, 1);
+
+        if ((ssl = SSL_new(ssl_ctx)) == NULL)
+                errx(1, "client ssl");
+
+        SSL_set_bio(ssl, bio, bio);
+        bio = NULL;
+
+        if (mtu > 0) {
+                SSL_set_options(ssl, SSL_OP_NO_QUERY_MTU);
+                SSL_set_mtu(ssl, mtu);
+        }
+
+        SSL_CTX_free(ssl_ctx);
+        BIO_free(bio);
+
+        return ssl;
+}
+
+static SSL *
+dtls_server(int sock, long options, long mtu)
+{
+        SSL_CTX *ssl_ctx = NULL;
+        SSL *ssl = NULL;
+        BIO *bio = NULL;
+
+        if ((bio = BIO_new_dgram(sock, BIO_NOCLOSE)) == NULL)
+                errx(1, "server bio");
+        if (!BIO_socket_nbio(sock, 1))
+                errx(1, "server nbio");
+
+        if ((ssl_ctx = SSL_CTX_new(DTLS_method())) == NULL)
+                errx(1, "server context");
+
+        SSL_CTX_set_cookie_generate_cb(ssl_ctx, dtls_cookie_generate);
+        SSL_CTX_set_cookie_verify_cb(ssl_ctx, dtls_cookie_verify);
+        SSL_CTX_set_options(ssl_ctx, options);
+        SSL_CTX_set_read_ahead(ssl_ctx, 1);
+
+        if (SSL_CTX_use_certificate_file(ssl_ctx, server_cert_file,
+            SSL_FILETYPE_PEM) != 1) {
+                fprintf(stderr, "FAIL: Failed to load server certificate");
+                goto failure;
+        }
+        if (SSL_CTX_use_PrivateKey_file(ssl_ctx, server_key_file,
+            SSL_FILETYPE_PEM) != 1) {
+                fprintf(stderr, "FAIL: Failed to load server private key");
+                goto failure;
+        }
+
+        if ((ssl = SSL_new(ssl_ctx)) == NULL)
+                errx(1, "server ssl");
+
+        SSL_set_bio(ssl, bio, bio);
+        bio = NULL;
+
+        if (mtu > 0) {
+                SSL_set_options(ssl, SSL_OP_NO_QUERY_MTU);
+                SSL_set_mtu(ssl, mtu);
+        }
+
+ failure:
+        SSL_CTX_free(ssl_ctx);
+        BIO_free(bio);
+
+        return ssl;
+}
+
+static int
+ssl_error(SSL *ssl, const char *name, const char *desc, int ssl_ret,
+    short *events)
+{
+        int ssl_err;
+
+        ssl_err = SSL_get_error(ssl, ssl_ret);
+
+        if (ssl_err == SSL_ERROR_WANT_READ) {
+                *events = POLLIN;
+        } else if (ssl_err == SSL_ERROR_WANT_WRITE) {
+                *events = POLLOUT;
+        } else if (ssl_err == SSL_ERROR_SYSCALL && errno == 0) {
+                /* Yup, this is apparently a thing... */
+                *events = 0;
+        } else {
+                fprintf(stderr, "FAIL: %s %s failed - ssl err = %d, errno = %d\n",
+                    name, desc, ssl_err, errno);
+                ERR_print_errors_fp(stderr);
+                return 0;
+        }
+
+        return 1;
+}
+
+static int
+do_connect(SSL *ssl, const char *name, int *done, short *events)
+{
+        int ssl_ret;
+
+        if ((ssl_ret = SSL_connect(ssl)) == 1) {
+                fprintf(stderr, "INFO: %s connect done\n", name);
+                *done = 1;
+                return 1;
+        }
+
+        return ssl_error(ssl, name, "connect", ssl_ret, events);
+}
+
+static int
+do_accept(SSL *ssl, const char *name, int *done, short *events)
+{
+        int ssl_ret;
+
+        if ((ssl_ret = SSL_accept(ssl)) == 1) {
+                fprintf(stderr, "INFO: %s accept done\n", name);
+                *done = 1;
+                return 1;
+        }
+
+        return ssl_error(ssl, name, "accept", ssl_ret, events);
+}
+
+static int
+do_shutdown(SSL *ssl, const char *name, int *done, short *events)
+{
+        int ssl_ret;
+
+        ssl_ret = SSL_shutdown(ssl);
+        if (ssl_ret == 1) {
+                fprintf(stderr, "INFO: %s shutdown done\n", name);
+                *done = 1;
+                return 1;
+        }
+        return ssl_error(ssl, name, "shutdown", ssl_ret, events);
+}
+
+typedef int (*ssl_func)(SSL *ssl, const char *name, int *done, short *events);
+
+static int
+do_client_server_loop(SSL *client, ssl_func client_func, SSL *server,
+    ssl_func server_func, struct pollfd pfd[2])
+{
+        int client_done = 0, server_done = 0;
+        int i = 0;
+
+        do {
+                if (poll(pfd, 2, poll_timeout(client, server)) == -1)
+                        err(1, "poll");
+
+                if (!client_done) {
+                        if (DTLSv1_handle_timeout(client) > 0)
+                                fprintf(stderr, "INFO: client timeout\n");
+                        if (!client_func(client, "client", &client_done,
+                            &pfd[0].events))
+                                return 0;
+                }
+                if (!server_done) {
+                        if (DTLSv1_handle_timeout(server) > 0)
+                                fprintf(stderr, "INFO: server timeout\n");
+                        if (!server_func(server, "server", &server_done,
+                            &pfd[1].events))
+                                return 0;
+                }
+        } while (i++ < 1000 && (!client_done || !server_done));
+
+        if (!client_done || !server_done)
+                fprintf(stderr, "FAIL: gave up\n");
+
+        return client_done && server_done;
+}
+
+struct dtls_test {
+        const unsigned char *desc;
+        const long mtu;
+        const long ssl_options;
+};
+
+static struct dtls_test dtls_tests[] = {
+        {
+                .desc = "DTLS without cookies",
+                .ssl_options = 0,
+        },
+        {
+                .desc = "DTLS with cookies",
+                .ssl_options = SSL_OP_COOKIE_EXCHANGE,
+        },
+        {
+                .desc = "DTLS with low MTU",
+                .mtu = 256,
+        },
+        {
+                .desc = "DTLS with low MTU and cookies",
+                .mtu = 256,
+                .ssl_options = SSL_OP_COOKIE_EXCHANGE,
+        },
+};
+
+#define N_DTLS_TESTS (sizeof(dtls_tests) / sizeof(*dtls_tests))
+
+static int
+dtlstest(struct dtls_test *dt)
+{
+        SSL *client = NULL, *server = NULL;
+        struct sockaddr_in server_sin;
+        struct pollfd pfd[2];
+        int client_sock = -1;
+        int server_sock = -1;
+        int failed = 1;
+
+        fprintf(stderr, "\n== Testing %s... ==\n", dt->desc);
+
+        if (!datagram_pair(&client_sock, &server_sock, &server_sin))
+                goto failure;
+
+        if ((client = dtls_client(client_sock, &server_sin, dt->mtu)) == NULL)
+                goto failure;
+        if ((server = dtls_server(server_sock, dt->ssl_options, dt->mtu)) == NULL)
+                goto failure;
+
+        pfd[0].fd = client_sock;
+        pfd[0].events = POLLOUT;
+        pfd[1].fd = server_sock;
+        pfd[1].events = 0;
+
+        if (!do_client_server_loop(client, do_connect, server, do_accept, pfd)) {
+                fprintf(stderr, "FAIL: client and server handshake failed\n");
+                goto failure;
+        }
+
+        /* XXX - do reads and writes. */
+
+        if (!do_client_server_loop(client, do_shutdown, server, do_shutdown, pfd)) {
+                fprintf(stderr, "FAIL: client and server shutdown failed\n");
+                goto failure;
+        }
+
+        fprintf(stderr, "INFO: Done!\n");
+
+        failed = 0;
+
+ failure:
+        if (client_sock != -1)
+                close(client_sock);
+        if (server_sock != -1)
+                close(server_sock);
+
+        SSL_free(client);
+        SSL_free(server);
+
+        return failed;
+}
+
+int
+main(int argc, char **argv)
+{
+        int failed = 0;
+        size_t i;
+
+        if (argc != 4) {
+                fprintf(stderr, "usage: %s keyfile certfile cafile\n",
+                    argv[0]);
+                exit(1);
+        }
+
+        server_key_file = argv[1];
+        server_cert_file = argv[2];
+        server_ca_file = argv[3];
+
+        for (i = 0; i < N_DTLS_TESTS; i++)
+                failed |= dtlstest(&dtls_tests[i]);
+
+        return failed;
+}