tests: Generate valid known_hosts file, fixing the current test

Previously, the file contained the known_hosts strings separated
by NULL bytes which somehow magically worked.

The test was also expecting all the keys from the file will have
the same key type, which was not indeed true.

Signed-off-by: Jakub Jelen <jjelen@redhat.com>
Reviewed-by: Andreas Schneider <asn@cryptomilk.org>

tests/unittests/torture_knownhosts_parsing.c

@@ -42,18 +42,24 @@ static int setup_knownhosts_file(void **state)
 
     nwritten = fwrite(LOCALHOST_PATTERN_ED25519,
                       sizeof(char),
-                      sizeof(LOCALHOST_PATTERN_ED25519),
+                      strlen(LOCALHOST_PATTERN_ED25519),
                       fp);
-    if (nwritten != sizeof(LOCALHOST_PATTERN_ED25519)) {
+    if (nwritten != strlen(LOCALHOST_PATTERN_ED25519)) {
+        fclose(fp);
+        return -1;
+    }
+
+    nwritten = fwrite("\n", sizeof(char), 1, fp);
+    if (nwritten != 1) {
         fclose(fp);
         return -1;
     }
 
     nwritten = fwrite(LOCALHOST_RSA_LINE,
                       sizeof(char),
-                      sizeof(LOCALHOST_RSA_LINE),
+                      strlen(LOCALHOST_RSA_LINE),
                       fp);
-    if (nwritten != sizeof(LOCALHOST_RSA_LINE)) {
+    if (nwritten != strlen(LOCALHOST_RSA_LINE)) {
         fclose(fp);
         return -1;
     }
@@ -210,6 +216,8 @@ static void torture_knownhosts_read_file(void **state)
     const char *knownhosts_file = *state;
     struct ssh_list *entry_list = NULL;
     struct ssh_iterator *it = NULL;
+    struct ssh_knownhosts_entry *entry = NULL;
+    enum ssh_keytypes_e type;
     int rc;
 
     rc = ssh_known_hosts_read_entries("localhost",
@@ -219,22 +227,27 @@ static void torture_knownhosts_read_file(void **state)
     assert_non_null(entry_list);
     it = ssh_list_get_iterator(entry_list);
     assert_non_null(it);
-    for (;it != NULL; it = it->next) {
-        struct ssh_knownhosts_entry *entry = NULL;
-        enum ssh_keytypes_e type;
 
-        entry = ssh_iterator_value(struct ssh_knownhosts_entry *, it);
-        assert_non_null(entry);
+    /* First key in known hosts file is ED25519 */
+    entry = ssh_iterator_value(struct ssh_knownhosts_entry *, it);
+    assert_non_null(entry);
 
-        assert_string_equal(entry->hostname, "localhost");
-        type = ssh_key_type(entry->publickey);
-        assert_int_equal(type, SSH_KEYTYPE_ED25519);
-    }
+    assert_string_equal(entry->hostname, "localhost");
+    type = ssh_key_type(entry->publickey);
+    assert_int_equal(type, SSH_KEYTYPE_ED25519);
+
+    it = it->next;
+
+    /* Second key in known hosts file is RSA */
+    entry = ssh_iterator_value(struct ssh_knownhosts_entry *, it);
+    assert_non_null(entry);
+
+    assert_string_equal(entry->hostname, "localhost");
+    type = ssh_key_type(entry->publickey);
+    assert_int_equal(type, SSH_KEYTYPE_RSA);
 
     it = ssh_list_get_iterator(entry_list);
     for (;it != NULL; it = it->next) {
-        struct ssh_knownhosts_entry *entry = NULL;
-
         entry = ssh_iterator_value(struct ssh_knownhosts_entry *, it);
         SSH_KNOWNHOSTS_ENTRY_FREE(entry);
     }