Add regress test coverage for SSL_shutdown().

This tests and codifies the behaviour of SSL_shutdown() with respect to
SSL_quiet_shutdown() and SSL_set_shutdown(). For now, only the legacy stack
(TLSv1.2) is tested, as there are currently some subtle differences with
the TLSv1.3 stack.

2 files changed, 546 insertions, 0 deletions

diff --git a/regress/lib/libssl/shutdown/Makefile b/regress/lib/libssl/shutdown/Makefile
new file mode 100644
index 00000000000..51305012d6f
--- /dev/null
+++ b/regress/lib/libssl/shutdown/Makefile
@@ -0,0 +1,18 @@
+#	$OpenBSD: Makefile,v 1.1 2024/01/19 08:29:08 jsing Exp $
+
+PROG=	shutdowntest
+LDADD=	-lssl -lcrypto
+DPADD=	${LIBSSL} ${LIBCRYPTO}
+WARNINGS=	Yes
+CFLAGS+=	-DLIBRESSL_INTERNAL -Werror
+
+REGRESS_TARGETS= \
+	regress-shutdowntest
+
+regress-shutdowntest: ${PROG}
+	./shutdowntest \
+	    ${.CURDIR}/../../libssl/certs/server.pem \
+	    ${.CURDIR}/../../libssl/certs/server.pem \
+	    ${.CURDIR}/../../libssl/certs/ca.pem
+
+.include <bsd.regress.mk>
diff --git a/regress/lib/libssl/shutdown/shutdowntest.c b/regress/lib/libssl/shutdown/shutdowntest.c
new file mode 100644
index 00000000000..7dea3a85012
--- /dev/null
+++ b/regress/lib/libssl/shutdown/shutdowntest.c
@@ -0,0 +1,528 @@
+/* $OpenBSD: shutdowntest.c,v 1.1 2024/01/19 08:29:08 jsing Exp $ */
+/*
+ * Copyright (c) 2020, 2021, 2024 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 <err.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;
+
+int debug = 0;
+
+static void
+hexdump(const unsigned char *buf, size_t len)
+{
+	size_t i;
+
+	for (i = 1; i <= len; i++)
+		fprintf(stderr, " 0x%02hhx,%s", buf[i - 1], i % 8 ? "" : "\n");
+
+	if (len % 8)
+		fprintf(stderr, "\n");
+}
+
+static SSL *
+tls_client(BIO *rbio, BIO *wbio)
+{
+	SSL_CTX *ssl_ctx = NULL;
+	SSL *ssl = NULL;
+
+	if ((ssl_ctx = SSL_CTX_new(TLS_method())) == NULL)
+		errx(1, "client context");
+
+	if ((ssl = SSL_new(ssl_ctx)) == NULL)
+		errx(1, "client ssl");
+
+	BIO_up_ref(rbio);
+	BIO_up_ref(wbio);
+
+	SSL_set_bio(ssl, rbio, wbio);
+
+	SSL_CTX_free(ssl_ctx);
+
+	return ssl;
+}
+
+static SSL *
+tls_server(BIO *rbio, BIO *wbio)
+{
+	SSL_CTX *ssl_ctx = NULL;
+	SSL *ssl = NULL;
+
+	if ((ssl_ctx = SSL_CTX_new(TLS_method())) == NULL)
+		errx(1, "server context");
+
+	SSL_CTX_set_dh_auto(ssl_ctx, 2);
+
+	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");
+
+	BIO_up_ref(rbio);
+	BIO_up_ref(wbio);
+
+	SSL_set_bio(ssl, rbio, wbio);
+
+ failure:
+	SSL_CTX_free(ssl_ctx);
+
+	return ssl;
+}
+
+static int
+ssl_error(SSL *ssl, const char *name, const char *desc, int ssl_ret)
+{
+	int ssl_err;
+
+	ssl_err = SSL_get_error(ssl, ssl_ret);
+
+	if (ssl_err == SSL_ERROR_WANT_READ) {
+		return 1;
+	} else if (ssl_err == SSL_ERROR_WANT_WRITE) {
+		return 1;
+	} else if (ssl_err == SSL_ERROR_SYSCALL && errno == 0) {
+		/* Yup, this is apparently a thing... */
+		return 1;
+	} 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;
+	}
+}
+
+static int
+do_connect(SSL *ssl, const char *name, int *done)
+{
+	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);
+}
+
+static int
+do_accept(SSL *ssl, const char *name, int *done)
+{
+	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);
+}
+
+static int
+do_read(SSL *ssl, const char *name, int *done)
+{
+	uint8_t buf[512];
+	int ssl_ret;
+
+	if ((ssl_ret = SSL_read(ssl, buf, sizeof(buf))) > 0) {
+		fprintf(stderr, "INFO: %s read done\n", name);
+		if (debug > 1)
+			hexdump(buf, ssl_ret);
+		*done = 1;
+		return 1;
+	}
+
+	return ssl_error(ssl, name, "read", ssl_ret);
+}
+
+static int
+do_write(SSL *ssl, const char *name, int *done)
+{
+	const uint8_t buf[] = "Hello, World!\n";
+	int ssl_ret;
+
+	if ((ssl_ret = SSL_write(ssl, buf, sizeof(buf))) > 0) {
+		fprintf(stderr, "INFO: %s write done\n", name);
+		*done = 1;
+		return 1;
+	}
+
+	return ssl_error(ssl, name, "write", ssl_ret);
+}
+
+static int
+do_shutdown(SSL *ssl, const char *name, int *done)
+{
+	int ssl_ret;
+
+	ssl_ret = SSL_shutdown(ssl);
+	if (ssl_ret == 1) {
+		fprintf(stderr, "INFO: %s shutdown done\n", name);
+		*done = 1;
+		return 1;
+	}
+
+	/* The astounding EOF condition. */
+	if (ssl_ret == -1 &&
+	    SSL_get_error(ssl, ssl_ret) == SSL_ERROR_SYSCALL && errno == 0) {
+		fprintf(stderr, "INFO: %s shutdown encountered EOF\n", name);
+		*done = 1;
+		return 1;
+	}
+
+	return ssl_error(ssl, name, "shutdown", ssl_ret);
+}
+
+typedef int (*ssl_func)(SSL *ssl, const char *name, int *done);
+
+static int
+do_client_server_loop(SSL *client, ssl_func client_func, SSL *server,
+    ssl_func server_func)
+{
+	int client_done = 0, server_done = 0;
+	int i = 0;
+
+	do {
+		if (!client_done) {
+			if (debug)
+				fprintf(stderr, "DEBUG: client loop\n");
+			if (!client_func(client, "client", &client_done))
+				return 0;
+		}
+		if (!server_done) {
+			if (debug)
+				fprintf(stderr, "DEBUG: server loop\n");
+			if (!server_func(server, "server", &server_done))
+				return 0;
+		}
+	} while (i++ < 100 && (!client_done || !server_done));
+
+	if (!client_done || !server_done)
+		fprintf(stderr, "FAIL: gave up\n");
+
+	return client_done && server_done;
+}
+
+static int
+do_shutdown_loop(SSL *client, SSL *server)
+{
+	int client_done = 0, server_done = 0;
+	int i = 0;
+
+	do {
+		if (!client_done) {
+			if (debug)
+				fprintf(stderr, "DEBUG: client loop\n");
+			if (!do_shutdown(client, "client", &client_done))
+				return 0;
+			if (client_done)
+				BIO_set_mem_eof_return(SSL_get_wbio(client), 0);
+		}
+		if (!server_done) {
+			if (debug)
+				fprintf(stderr, "DEBUG: server loop\n");
+			if (!do_shutdown(server, "server", &server_done))
+				return 0;
+			if (server_done)
+				BIO_set_mem_eof_return(SSL_get_wbio(server), 0);
+		}
+	} while (i++ < 100 && (!client_done || !server_done));
+
+	if (!client_done || !server_done)
+		fprintf(stderr, "FAIL: gave up\n");
+
+	return client_done && server_done;
+}
+
+static void
+ssl_msg_callback(int is_write, int version, int content_type, const void *buf,
+    size_t len, SSL *ssl, void *arg)
+{
+	const uint8_t *msg = buf;
+	int *close_notify = arg;
+
+	if (is_write || content_type != SSL3_RT_ALERT)
+		return;
+	if (len == 2 && msg[0] == SSL3_AL_WARNING && msg[1] == SSL_AD_CLOSE_NOTIFY)
+		*close_notify = 1;
+}
+
+struct shutdown_test {
+	const unsigned char *desc;
+	int client_quiet_shutdown;
+	int client_set_shutdown;
+	int want_client_shutdown;
+	int want_client_close_notify;
+	int server_quiet_shutdown;
+	int server_set_shutdown;
+	int want_server_shutdown;
+	int want_server_close_notify;
+};
+
+static const struct shutdown_test shutdown_tests[] = {
+	{
+		.desc = "bidirectional shutdown",
+		.want_client_close_notify = 1,
+		.want_client_shutdown = SSL_SENT_SHUTDOWN | SSL_RECEIVED_SHUTDOWN,
+		.want_server_close_notify = 1,
+		.want_server_shutdown = SSL_SENT_SHUTDOWN | SSL_RECEIVED_SHUTDOWN,
+	},
+	{
+		.desc = "client quiet shutdown",
+		.client_quiet_shutdown = 1,
+		.want_client_shutdown = SSL_SENT_SHUTDOWN | SSL_RECEIVED_SHUTDOWN,
+		.want_server_shutdown = SSL_SENT_SHUTDOWN,
+	},
+	{
+		.desc = "server quiet shutdown",
+		.server_quiet_shutdown = 1,
+		.want_client_shutdown = SSL_SENT_SHUTDOWN,
+		.want_server_shutdown = SSL_SENT_SHUTDOWN | SSL_RECEIVED_SHUTDOWN,
+	},
+	{
+		.desc = "both quiet shutdown",
+		.client_quiet_shutdown = 1,
+		.server_quiet_shutdown = 1,
+		.want_client_shutdown = SSL_SENT_SHUTDOWN | SSL_RECEIVED_SHUTDOWN,
+		.want_server_shutdown = SSL_SENT_SHUTDOWN | SSL_RECEIVED_SHUTDOWN,
+	},
+	{
+		.desc = "client set sent shutdown",
+		.client_set_shutdown = SSL_SENT_SHUTDOWN,
+		.want_client_close_notify = 1,
+		.want_client_shutdown = SSL_SENT_SHUTDOWN | SSL_RECEIVED_SHUTDOWN,
+		.want_server_shutdown = SSL_SENT_SHUTDOWN,
+	},
+	{
+		.desc = "client set received shutdown",
+		.client_set_shutdown = SSL_RECEIVED_SHUTDOWN,
+		.want_client_shutdown = SSL_SENT_SHUTDOWN | SSL_RECEIVED_SHUTDOWN,
+		.want_server_close_notify = 1,
+		.want_server_shutdown = SSL_SENT_SHUTDOWN | SSL_RECEIVED_SHUTDOWN,
+	},
+	{
+		.desc = "client set sent/received shutdown",
+		.client_set_shutdown = SSL_SENT_SHUTDOWN | SSL_RECEIVED_SHUTDOWN,
+		.want_client_shutdown = SSL_SENT_SHUTDOWN | SSL_RECEIVED_SHUTDOWN,
+		.want_server_shutdown = SSL_SENT_SHUTDOWN,
+	},
+	{
+		.desc = "server set sent shutdown",
+		.server_set_shutdown = SSL_SENT_SHUTDOWN,
+		.want_client_shutdown = SSL_SENT_SHUTDOWN,
+		.want_server_close_notify = 1,
+		.want_server_shutdown = SSL_SENT_SHUTDOWN | SSL_RECEIVED_SHUTDOWN,
+	},
+	{
+		.desc = "server set received shutdown",
+		.server_set_shutdown = SSL_RECEIVED_SHUTDOWN,
+		.want_client_close_notify = 1,
+		.want_client_shutdown = SSL_SENT_SHUTDOWN | SSL_RECEIVED_SHUTDOWN,
+		.want_server_shutdown = SSL_SENT_SHUTDOWN | SSL_RECEIVED_SHUTDOWN,
+	},
+	{
+		.desc = "server set sent/received shutdown",
+		.server_set_shutdown = SSL_SENT_SHUTDOWN | SSL_RECEIVED_SHUTDOWN,
+		.want_client_shutdown = SSL_SENT_SHUTDOWN,
+		.want_server_shutdown = SSL_SENT_SHUTDOWN | SSL_RECEIVED_SHUTDOWN,
+	},
+};
+
+#define N_TLS_TESTS (sizeof(shutdown_tests) / sizeof(*shutdown_tests))
+
+static int
+shutdowntest(uint16_t ssl_version, const char *ssl_version_name,
+    const struct shutdown_test *st)
+{
+	BIO *client_wbio = NULL, *server_wbio = NULL;
+	SSL *client = NULL, *server = NULL;
+	int client_close_notify = 0, server_close_notify = 0;
+	int shutdown, ssl_err;
+	int failed = 1;
+
+	fprintf(stderr, "\n== Testing %s, %s... ==\n", ssl_version_name,
+	    st->desc);
+
+	if ((client_wbio = BIO_new(BIO_s_mem())) == NULL)
+		goto failure;
+	if (BIO_set_mem_eof_return(client_wbio, -1) <= 0)
+		goto failure;
+
+	if ((server_wbio = BIO_new(BIO_s_mem())) == NULL)
+		goto failure;
+	if (BIO_set_mem_eof_return(server_wbio, -1) <= 0)
+		goto failure;
+
+	if ((client = tls_client(server_wbio, client_wbio)) == NULL)
+		goto failure;
+	if (!SSL_set_min_proto_version(client, ssl_version))
+		goto failure;
+	if (!SSL_set_max_proto_version(client, ssl_version))
+		goto failure;
+
+	if ((server = tls_server(client_wbio, server_wbio)) == NULL)
+		goto failure;
+	if (!SSL_set_min_proto_version(server, ssl_version))
+		goto failure;
+	if (!SSL_set_max_proto_version(server, ssl_version))
+		goto failure;
+
+	if (!do_client_server_loop(client, do_connect, server, do_accept)) {
+		fprintf(stderr, "FAIL: client and server handshake failed\n");
+		goto failure;
+	}
+
+	if (!do_client_server_loop(client, do_write, server, do_read)) {
+		fprintf(stderr, "FAIL: client write and server read I/O failed\n");
+		goto failure;
+	}
+
+	if (!do_client_server_loop(client, do_read, server, do_write)) {
+		fprintf(stderr, "FAIL: client read and server write I/O failed\n");
+		goto failure;
+	}
+
+	/* Seemingly this is the only way to find out about alerts... */
+	SSL_set_msg_callback(client, ssl_msg_callback);
+	SSL_set_msg_callback_arg(client, &client_close_notify);
+	SSL_set_msg_callback(server, ssl_msg_callback);
+	SSL_set_msg_callback_arg(server, &server_close_notify);
+
+	SSL_set_shutdown(client, st->client_set_shutdown);
+	SSL_set_shutdown(server, st->server_set_shutdown);
+
+	SSL_set_quiet_shutdown(client, st->client_quiet_shutdown);
+	SSL_set_quiet_shutdown(server, st->server_quiet_shutdown);
+
+	if (!do_shutdown_loop(client, server)) {
+		fprintf(stderr, "FAIL: client and server shutdown failed\n");
+		goto failure;
+	}
+
+	if ((shutdown = SSL_get_shutdown(client)) != st->want_client_shutdown) {
+		fprintf(stderr, "FAIL: client shutdown flags = %x, want %x\n",
+		    shutdown, st->want_client_shutdown);
+		goto failure;
+	}
+	if ((shutdown = SSL_get_shutdown(server)) != st->want_server_shutdown) {
+		fprintf(stderr, "FAIL: server shutdown flags = %x, want %x\n",
+		    shutdown, st->want_server_shutdown);
+		goto failure;
+	}
+
+	if (client_close_notify != st->want_client_close_notify) {
+		fprintf(stderr, "FAIL: client close notify = %d, want %d\n",
+		    client_close_notify, st->want_client_close_notify);
+		goto failure;
+	}
+	if (server_close_notify != st->want_server_close_notify) {
+		fprintf(stderr, "FAIL: server close notify = %d, want %d\n",
+		    server_close_notify, st->want_server_close_notify);
+		goto failure;
+	}
+
+	if (st->want_client_close_notify) {
+		if ((ssl_err = SSL_get_error(client, 0)) != SSL_ERROR_ZERO_RETURN) {
+			fprintf(stderr, "FAIL: client ssl error = %d, want %d\n",
+			    ssl_err, SSL_ERROR_ZERO_RETURN);
+			goto failure;
+		}
+	}
+	if (st->want_server_close_notify) {
+		if ((ssl_err = SSL_get_error(server, 0)) != SSL_ERROR_ZERO_RETURN) {
+			fprintf(stderr, "FAIL: server ssl error = %d, want %d\n",
+			    ssl_err, SSL_ERROR_ZERO_RETURN);
+			goto failure;
+		}
+	}
+
+	fprintf(stderr, "INFO: Done!\n");
+
+	failed = 0;
+
+ failure:
+	BIO_free(client_wbio);
+	BIO_free(server_wbio);
+
+	SSL_free(client);
+	SSL_free(server);
+
+	return failed;
+}
+
+struct ssl_version {
+	uint16_t version;
+	const char *name;
+};
+
+struct ssl_version ssl_versions[] = {
+	{
+		.version = TLS1_2_VERSION,
+		.name = SSL_TXT_TLSV1_2,
+	},
+#if 0
+	{
+		.version = TLS1_3_VERSION,
+		.name = SSL_TXT_TLSV1_3,
+	},
+#endif
+};
+
+#define N_SSL_VERSIONS (sizeof(ssl_versions) / sizeof(*ssl_versions))
+
+int
+main(int argc, char **argv)
+{
+	const struct ssl_version *sv;
+	int failed = 0;
+	size_t i, j;
+
+	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_SSL_VERSIONS; i++) {
+		sv = &ssl_versions[i];
+		for (j = 0; j < N_TLS_TESTS; j++) {
+			failed |= shutdowntest(sv->version, sv->name,
+			    &shutdown_tests[j]);
+		}
+	}
+
+	return failed;
+}