apps: introduce app_malloc_array()

Similar to app_malloc(), provides a wrapper for OPENSSL_malloc_array()
that bails out when a NULL pointer is returned.

Signed-off-by: Eugene Syromiatnikov <esyr@openssl.org>

Reviewed-by: Paul Dale <ppzgs1@gmail.com>
Reviewed-by: Dmitry Belyavskiy <beldmit@gmail.com>
Reviewed-by: Neil Horman <nhorman@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/28444)

apps/include/apps.h

@@ -230,7 +230,26 @@ typedef struct ca_db_st {
 extern int do_updatedb(CA_DB *db, time_t *now);
 
 void app_bail_out(char *fmt, ...);
+/**
+ * OPENSSL_malloc() wrapper that bails out with a meaningful message on failure.
+ *
+ * @param sz   Number of bytes to allocate.
+ * @param what Description of the object being allocated.
+ * @return On success, returns a pointer to the newly allocated memory.
+ *         on failure, calls app_bail_out() to terminate the program.
+ */
 void *app_malloc(size_t sz, const char *what);
+/**
+ * OPENSSL_malloc_array() wrapper that bails out with a meaningful message
+ * on failure.
+ *
+ * @param n    Number of objects to allocate memory for.
+ * @param sz   Size in bytes of each object to be allocated.
+ * @param what Description of the array being allocated.
+ * @return On success, returns a pointer to the newly allocated memory;
+ *         on failure, calls app_bail_out() to terminate the program.
+ */
+void *app_malloc_array(size_t n, size_t sz, const char *what);
 
 /* load_serial, save_serial, and rotate_serial are also used for CRL numbers */
 BIGNUM *load_serial(const char *serialfile, int *exists, int create,

apps/lib/apps.c

@@ -695,6 +695,16 @@ void *app_malloc(size_t sz, const char *what)
     return vp;
 }
 
+void *app_malloc_array(size_t n, size_t sz, const char *what)
+{
+    void *vp = OPENSSL_malloc_array(n, sz);
+
+    if (vp == NULL)
+        app_bail_out("%s: Could not allocate %zu*%zu bytes for %s\n",
+                     opt_getprog(), n, sz, what);
+    return vp;
+}
+
 char *next_item(char *opt) /* in list separated by comma and/or space */
 {
     /* advance to separator (comma or whitespace), if any */

test/testutil/apps_shims.c

@@ -29,6 +29,21 @@ void *app_malloc(size_t sz, const char *what)
     return vp;
 }
 
+void *app_malloc_array(size_t n, size_t sz, const char *what)
+{
+    void *vp;
+
+    /*
+     * Instead of exiting with a failure, abort() is called which makes sure
+     * that there will be a good stack trace for debugging purposes.
+     */
+    if (!TEST_ptr(vp = OPENSSL_malloc_array(n, sz))) {
+        TEST_info("Could not allocate %zu*%zu bytes for %s\n", n, sz, what);
+        abort();
+    }
+    return vp;
+}
+
 /* shim to prevent sucking in too much from apps */
 
 int opt_legacy_okay(void)