Sanitize op stack for error conditions

We save the stacks to an array and store the array for the error handler to
access.

For SAFER, we traverse the array, and deep copy any op arrays (procedures). As
we make these copies, we check for operators that do *not* exist in systemdict,
when we find one, we replace the operator with a name object (of the form
"/--opname--").

1 files changed, 78 insertions, 0 deletions

diff --git a/psi/istack.c b/psi/istack.c
index 2c030f817..1bfcde4d7 100644
--- a/psi/istack.c
+++ b/psi/istack.c
@@ -27,6 +27,10 @@
 #include "iutil.h"
 #include "ivmspace.h"		/* for local/global test */
 #include "store.h"
+#include "icstate.h"
+#include "iname.h"
+#include "dstack.h"
+#include "idict.h"
 
 /* Forward references */
 static void init_block(ref_stack_t *pstack, const ref *pblock_array,
@@ -294,6 +298,80 @@ ref_stack_store_check(const ref_stack_t *pstack, ref *parray, uint count,
     return 0;
 }
 
+int
+ref_stack_array_sanitize(i_ctx_t *i_ctx_p, ref *sarr, ref *darr)
+{
+    int i, code;
+    ref obj, arr2;
+    ref *pobj2;
+    gs_memory_t *mem = (gs_memory_t *)idmemory->current;
+
+    if (!r_is_array(sarr) || !r_has_type(darr, t_array))
+        return_error(gs_error_typecheck);
+
+    for (i = 0; i < r_size(sarr); i++) {
+        code = array_get(mem, sarr, i, &obj);
+        if (code < 0)
+            make_null(&obj);
+        switch(r_type(&obj)) {
+          case t_operator:
+          {
+            int index = op_index(&obj);
+
+            if (index > 0 && index < op_def_count) {
+                const byte *data = (const byte *)(op_index_def(index)->oname + 1);
+                if (dict_find_string(systemdict, (const char *)data, &pobj2) <= 0) {
+                    byte *s = gs_alloc_bytes(mem, strlen((char *)data) + 5, "ref_stack_array_sanitize");
+                    if (s) {
+                        s[0] =  '\0';
+                        strcpy((char *)s, "--");
+                        strcpy((char *)s + 2, (char *)data);
+                        strcpy((char *)s + strlen((char *)data) + 2, "--");
+                    }
+                    else {
+                        s = (byte *)data;
+                    }
+                    code = name_ref(imemory, s, strlen((char *)s), &obj, 1);
+                    if (code < 0) make_null(&obj);
+                    if (s != data)
+                        gs_free_object(mem, s, "ref_stack_array_sanitize");
+                }
+            }
+            else {
+                make_null(&obj);
+            }
+            ref_assign(darr->value.refs + i, &obj);
+            break;
+          }
+          case t_array:
+          case t_shortarray:
+          case t_mixedarray:
+          {
+            int attrs = r_type_attrs(&obj) & (a_write | a_read | a_execute | a_executable);
+            /* We only want to copy executable arrays */
+            if (attrs & (a_execute | a_executable)) {
+                code = ialloc_ref_array(&arr2, attrs, r_size(&obj), "ref_stack_array_sanitize");
+                if (code < 0) {
+                    make_null(&arr2);
+                }
+                else {
+                    code = ref_stack_array_sanitize(i_ctx_p, &obj, &arr2);
+                }
+                ref_assign(darr->value.refs + i, &arr2);
+            }
+            else {
+                ref_assign(darr->value.refs + i, &obj);
+            }
+            break;
+          }
+          default:
+            ref_assign(darr->value.refs + i, &obj);
+        }
+    }
+    return 0;
+}
+
+
 /*
  * Store the top 'count' elements of a stack, starting 'skip' elements below
  * the top, into an array, with or without store/undo checking.  age=-1 for