Extend the auto DH testing to check DH sizes

Check that the size of the DH parameters we select changes according to
the size of the certificate key or symmetric cipher (if no certificate).

Reviewed-by: Richard Levitte <levitte@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/13368)

1 files changed, 157 insertions, 0 deletions

diff --git a/test/sslapitest.c b/test/sslapitest.c
index 6b49d2a250..19421947de 100644
--- a/test/sslapitest.c
+++ b/test/sslapitest.c
@@ -75,6 +75,14 @@ static char *cert = NULL;
 static char *privkey = NULL;
 static char *cert2 = NULL;
 static char *privkey2 = NULL;
+static char *cert1024 = NULL;
+static char *privkey1024 = NULL;
+static char *cert3072 = NULL;
+static char *privkey3072 = NULL;
+static char *cert4096 = NULL;
+static char *privkey4096 = NULL;
+static char *cert8192 = NULL;
+static char *privkey8192 = NULL;
 static char *srpvfile = NULL;
 static char *tmpfilename = NULL;
 
@@ -8238,6 +8246,114 @@ static int test_set_tmp_dh(int idx)
 
     return testresult;
 }
+
+/*
+ * Test the auto DH keys are appropriately sized
+ */
+static int test_dh_auto(int idx)
+{
+    SSL_CTX *cctx = NULL, *sctx = NULL;
+    SSL *clientssl = NULL, *serverssl = NULL;
+    int testresult = 0;
+    EVP_PKEY *tmpkey = NULL;
+    char *thiscert = NULL, *thiskey = NULL;
+    size_t expdhsize = 0;
+    const char *ciphersuite = "DHE-RSA-AES128-SHA";
+
+    switch (idx) {
+    case 0:
+        /* The FIPS provider doesn't support this DH size - so we ignore it */
+        if (is_fips)
+            return 1;
+        thiscert = cert1024;
+        thiskey = privkey1024;
+        expdhsize = 1024;
+        break;
+    case 1:
+        /* 2048 bit prime */
+        thiscert = cert;
+        thiskey = privkey;
+        expdhsize = 2048;
+        break;
+    case 2:
+        thiscert = cert3072;
+        thiskey = privkey3072;
+        expdhsize = 3072;
+        break;
+    case 3:
+        thiscert = cert4096;
+        thiskey = privkey4096;
+        expdhsize = 4096;
+        break;
+    case 4:
+        thiscert = cert8192;
+        thiskey = privkey8192;
+        expdhsize = 8192;
+        break;
+    /* No certificate cases */
+    case 5:
+        /* The FIPS provider doesn't support this DH size - so we ignore it */
+        if (is_fips)
+            return 1;
+        ciphersuite = "ADH-AES128-SHA256:@SECLEVEL=0";
+        expdhsize = 1024;
+        break;
+    case 6:
+        ciphersuite = "ADH-AES256-SHA256:@SECLEVEL=0";
+        expdhsize = 3072;
+        break;
+    default:
+        TEST_error("Invalid text index");
+        goto end;
+    }
+
+    if (!TEST_true(create_ssl_ctx_pair(libctx, TLS_server_method(),
+                                       TLS_client_method(),
+                                       0,
+                                       0,
+                                       &sctx, &cctx, thiscert, thiskey)))
+        goto end;
+
+    if (!TEST_true(create_ssl_objects(sctx, cctx, &serverssl, &clientssl,
+                                      NULL, NULL)))
+        goto end;
+
+    if (!TEST_true(SSL_set_dh_auto(serverssl, 1))
+            || !TEST_true(SSL_set_min_proto_version(serverssl, TLS1_2_VERSION))
+            || !TEST_true(SSL_set_max_proto_version(serverssl, TLS1_2_VERSION))
+            || !TEST_true(SSL_set_cipher_list(serverssl, ciphersuite))
+            || !TEST_true(SSL_set_cipher_list(clientssl, ciphersuite)))
+        goto end;
+
+    /*
+     * Send the server's first flight. At this point the server has created the
+     * temporary DH key but hasn't finished using it yet. Once used it is
+     * removed, so we cannot test it.
+     */
+    if (!TEST_int_le(SSL_connect(clientssl), 0)
+            || !TEST_int_le(SSL_accept(serverssl), 0))
+        goto end;
+
+    if (!TEST_int_gt(SSL_get_tmp_key(serverssl, &tmpkey), 0))
+        goto end;
+    if (!TEST_size_t_eq(EVP_PKEY_bits(tmpkey), expdhsize))
+        goto end;
+
+    if (!TEST_true(create_ssl_connection(serverssl, clientssl, SSL_ERROR_NONE)))
+        goto end;
+
+    testresult = 1;
+
+ end:
+    SSL_free(serverssl);
+    SSL_free(clientssl);
+    SSL_CTX_free(sctx);
+    SSL_CTX_free(cctx);
+    EVP_PKEY_free(tmpkey);
+
+    return testresult;
+
+}
 # endif /* OPENSSL_NO_DH */
 #endif /* OPENSSL_NO_TLS1_2 */
 
@@ -8330,6 +8446,38 @@ int setup_tests(void)
     if (privkey2 == NULL)
         goto err;
 
+    cert1024 = test_mk_file_path(certsdir, "ee-cert-1024.pem");
+    if (cert1024 == NULL)
+        goto err;
+
+    privkey1024 = test_mk_file_path(certsdir, "ee-key-1024.pem");
+    if (privkey1024 == NULL)
+        goto err;
+
+    cert3072 = test_mk_file_path(certsdir, "ee-cert-3072.pem");
+    if (cert3072 == NULL)
+        goto err;
+
+    privkey3072 = test_mk_file_path(certsdir, "ee-key-3072.pem");
+    if (privkey3072 == NULL)
+        goto err;
+
+    cert4096 = test_mk_file_path(certsdir, "ee-cert-4096.pem");
+    if (cert4096 == NULL)
+        goto err;
+
+    privkey4096 = test_mk_file_path(certsdir, "ee-key-4096.pem");
+    if (privkey4096 == NULL)
+        goto err;
+
+    cert8192 = test_mk_file_path(certsdir, "ee-cert-8192.pem");
+    if (cert8192 == NULL)
+        goto err;
+
+    privkey8192 = test_mk_file_path(certsdir, "ee-key-8192.pem");
+    if (privkey8192 == NULL)
+        goto err;
+
 #if !defined(OPENSSL_NO_KTLS) && !defined(OPENSSL_NO_SOCK)
 # if !defined(OPENSSL_NO_TLS1_2) || !defined(OPENSSL_NO_TLS1_3)
     ADD_ALL_TESTS(test_ktls, 32);
@@ -8448,6 +8596,7 @@ int setup_tests(void)
     ADD_TEST(test_ssl_dup);
 # ifndef OPENSSL_NO_DH
     ADD_ALL_TESTS(test_set_tmp_dh, 11);
+    ADD_ALL_TESTS(test_dh_auto, 7);
 # endif
 #endif
     return 1;
@@ -8469,6 +8618,14 @@ void cleanup_tests(void)
     OPENSSL_free(privkey);
     OPENSSL_free(cert2);
     OPENSSL_free(privkey2);
+    OPENSSL_free(cert1024);
+    OPENSSL_free(privkey1024);
+    OPENSSL_free(cert3072);
+    OPENSSL_free(privkey3072);
+    OPENSSL_free(cert4096);
+    OPENSSL_free(privkey4096);
+    OPENSSL_free(cert8192);
+    OPENSSL_free(privkey8192);
     bio_s_mempacket_test_free();
     bio_s_always_retry_free();
     OSSL_PROVIDER_unload(defctxnull);