Make SSL_set_tlsext_host_name no effect from server side

Documentation and test cases are also updated

Reviewed-by: Ben Kaduk <kaduk@mit.edu>
Reviewed-by: Matt Caswell <matt@openssl.org>
Reviewed-by: Rich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/3783)

1 files changed, 241 insertions, 0 deletions

diff --git a/test/servername_test.c b/test/servername_test.c
new file mode 100644
index 0000000000..afb745709e
--- /dev/null
+++ b/test/servername_test.c
@@ -0,0 +1,241 @@
+/*
+ * Copyright 2017 The OpenSSL Project Authors. All Rights Reserved.
+ * Copyright 2017 BaishanCloud. All rights reserved.
+ *
+ * Licensed under the OpenSSL license (the "License").  You may not use
+ * this file except in compliance with the License.  You can obtain a copy
+ * in the file LICENSE in the source distribution or at
+ * https://www.openssl.org/source/license.html
+ */
+
+#include <string.h>
+
+#include <openssl/opensslconf.h>
+#include <openssl/bio.h>
+#include <openssl/crypto.h>
+#include <openssl/evp.h>
+#include <openssl/ssl.h>
+#include <openssl/err.h>
+#include <time.h>
+
+#include "../ssl/packet_locl.h"
+
+#include "testutil.h"
+#include "e_os.h"
+
+#define CLIENT_VERSION_LEN      2
+
+static const char *host = "dummy-host";
+
+static int get_sni_from_client_hello(BIO *bio, char **sni)
+{
+    long len;
+    unsigned char *data;
+    PACKET pkt = {0}, pkt2 = {0}, pkt3 = {0}, pkt4 = {0}, pkt5 = {0};
+    unsigned int servname_type = 0, type = 0;
+    int ret = 0;
+
+    len = BIO_get_mem_data(bio, (char **)&data);
+    if (!TEST_true(PACKET_buf_init(&pkt, data, len))
+               /* Skip the record header */
+            || !PACKET_forward(&pkt, SSL3_RT_HEADER_LENGTH)
+               /* Skip the handshake message header */
+            || !TEST_true(PACKET_forward(&pkt, SSL3_HM_HEADER_LENGTH))
+               /* Skip client version and random */
+            || !TEST_true(PACKET_forward(&pkt, CLIENT_VERSION_LEN
+                                               + SSL3_RANDOM_SIZE))
+               /* Skip session id */
+            || !TEST_true(PACKET_get_length_prefixed_1(&pkt, &pkt2))
+               /* Skip ciphers */
+            || !TEST_true(PACKET_get_length_prefixed_2(&pkt, &pkt2))
+               /* Skip compression */
+            || !TEST_true(PACKET_get_length_prefixed_1(&pkt, &pkt2))
+               /* Extensions len */
+            || !TEST_true(PACKET_as_length_prefixed_2(&pkt, &pkt2)))
+        goto end;
+
+    /* Loop through all extensions for SNI */
+    while (PACKET_remaining(&pkt2)) {
+        if (!TEST_true(PACKET_get_net_2(&pkt2, &type))
+                || !TEST_true(PACKET_get_length_prefixed_2(&pkt2, &pkt3)))
+            goto end;
+        if (type == TLSEXT_TYPE_server_name) {
+            if (!TEST_true(PACKET_get_length_prefixed_2(&pkt3, &pkt4))
+                    || !TEST_uint_ne(PACKET_remaining(&pkt4), 0)
+                    || !TEST_true(PACKET_get_1(&pkt4, &servname_type))
+                    || !TEST_uint_eq(servname_type, TLSEXT_NAMETYPE_host_name)
+                    || !TEST_true(PACKET_get_length_prefixed_2(&pkt4, &pkt5))
+                    || !TEST_uint_le(PACKET_remaining(&pkt5), TLSEXT_MAXLEN_host_name)
+                    || !TEST_false(PACKET_contains_zero_byte(&pkt5))
+                    || !TEST_true(PACKET_strndup(&pkt5, sni)))
+                goto end;
+            ret = 1;
+            goto end;
+        }
+    }
+end:
+    return ret;
+}
+
+static int client_setup_sni_before_state()
+{
+    SSL_CTX *ctx;
+    SSL *con = NULL;
+    BIO *rbio;
+    BIO *wbio;
+    char *hostname = NULL;
+    int ret = 0;
+
+    /* use TLS_method to blur 'side' */
+    ctx = SSL_CTX_new(TLS_method());
+    if (!TEST_ptr(ctx))
+        goto end;
+
+    con = SSL_new(ctx);
+    if (!TEST_ptr(con))
+        goto end;
+
+    /* set SNI before 'client side' is set */
+    SSL_set_tlsext_host_name(con, host);
+
+    rbio = BIO_new(BIO_s_mem());
+    wbio = BIO_new(BIO_s_mem());
+    if (!TEST_ptr(rbio)|| !TEST_ptr(wbio)) {
+        BIO_free(rbio);
+        BIO_free(wbio);
+        goto end;
+    }
+
+    SSL_set_bio(con, rbio, wbio);
+
+    if (!TEST_int_le(SSL_connect(con), 0))
+        /* This shouldn't succeed because we don't have a server! */
+        goto end;
+    if (!TEST_true(get_sni_from_client_hello(wbio, &hostname)))
+        /* no SNI in client hello */
+        goto end;
+    if (!TEST_str_eq(hostname, host))
+        /* incorrect SNI value */
+        goto end;
+    ret = 1;
+end:
+    OPENSSL_free(hostname);
+    SSL_free(con);
+    SSL_CTX_free(ctx);
+    return ret;
+}
+
+static int client_setup_sni_after_state()
+{
+    SSL_CTX *ctx;
+    SSL *con = NULL;
+    BIO *rbio;
+    BIO *wbio;
+    char *hostname = NULL;
+    int ret = 0;
+
+    /* use TLS_method to blur 'side' */
+    ctx = SSL_CTX_new(TLS_method());
+    if (!TEST_ptr(ctx))
+        goto end;
+
+    con = SSL_new(ctx);
+    if (!TEST_ptr(con))
+        goto end;
+
+    rbio = BIO_new(BIO_s_mem());
+    wbio = BIO_new(BIO_s_mem());
+    if (!TEST_ptr(rbio)|| !TEST_ptr(wbio)) {
+        BIO_free(rbio);
+        BIO_free(wbio);
+        goto end;
+    }
+
+    SSL_set_bio(con, rbio, wbio);
+    SSL_set_connect_state(con);
+
+    /* set SNI after 'client side' is set */
+    SSL_set_tlsext_host_name(con, host);
+
+    if (!TEST_int_le(SSL_connect(con), 0))
+        /* This shouldn't succeed because we don't have a server! */
+        goto end;
+    if (!TEST_true(get_sni_from_client_hello(wbio, &hostname)))
+        /* no SNI in client hello */
+        goto end;
+    if (!TEST_str_eq(hostname, host))
+        /* incorrect SNI value */
+        goto end;
+    ret = 1;
+end:
+    OPENSSL_free(hostname);
+    SSL_free(con);
+    SSL_CTX_free(ctx);
+    return ret;
+}
+
+static int server_setup_sni()
+{
+    SSL_CTX *ctx;
+    SSL *con = NULL;
+    BIO *rbio;
+    BIO *wbio;
+    int ret = 0;
+
+    /* use TLS_server_method to choose 'server-side' */
+    ctx = SSL_CTX_new(TLS_server_method());
+    if (!TEST_ptr(ctx))
+        goto end;
+
+    con = SSL_new(ctx);
+    if (!TEST_ptr(con))
+        goto end;
+
+    rbio = BIO_new(BIO_s_mem());
+    wbio = BIO_new(BIO_s_mem());
+    if (!TEST_ptr(rbio)|| !TEST_ptr(wbio)) {
+        BIO_free(rbio);
+        BIO_free(wbio);
+        goto end;
+    }
+
+    SSL_set_bio(con, rbio, wbio);
+
+    /* set SNI at server side */
+    SSL_set_tlsext_host_name(con, host);
+
+    if (!TEST_int_le(SSL_accept(con), 0))
+        /* This shouldn't succeed because we have nothing to listen on */
+        goto end;
+    if (!TEST_ptr_null(SSL_get_servername(con, TLSEXT_NAMETYPE_host_name)))
+        /* SNI should be cleared by SSL_accpet */
+        goto end;
+    ret = 1;
+end:
+    SSL_free(con);
+    SSL_CTX_free(ctx);
+    return ret;
+}
+
+typedef int (*sni_test_fn)(void);
+
+static sni_test_fn sni_test_fns[3] = {
+    client_setup_sni_before_state,
+    client_setup_sni_after_state,
+    server_setup_sni
+};
+
+static int test_servername(int test)
+{
+    /*
+     * For each test set up an SSL_CTX and SSL and see
+     * what SNI behaves.
+     */
+    return sni_test_fns[test]();
+}
+
+int setup_tests(void)
+{
+    ADD_ALL_TESTS(test_servername, OSSL_NELEM(sni_test_fns));
+    return 1;
+}