1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
|
The following patch was adapted for GNU Ghostscript
by Mark H Weaver <mhw@netris.org> based on:
http://git.ghostscript.com/?p=ghostpdl.git;a=commit;h=6d444c273da5499a4cd72f21cb6d4c9a5256807d
From 6d444c273da5499a4cd72f21cb6d4c9a5256807d Mon Sep 17 00:00:00 2001
From: Chris Liddell <chris.liddell@artifex.com>
Date: Wed, 5 Oct 2016 09:55:55 +0100
Subject: [PATCH] Bug 697178: Add a file permissions callback
For the rare occasions when the graphics library directly opens a file
(currently for reading), this allows us to apply any restrictions on
file access normally applied in the interpteter.
---
base/gsicc_manage.c | 10 ++++++----
base/gslibctx.c | 12 +++++++++++-
base/gslibctx.h | 7 +++++++
psi/imain.c | 2 ++
psi/int.mak | 2 +-
psi/zfile.c | 19 +++++++++++++++++++
psi/zfile.h | 7 +++++++
7 files changed, 53 insertions(+), 6 deletions(-)
diff --git a/base/gsicc_manage.c b/base/gsicc_manage.c
index 931c2a6..e9c09c3 100644
--- a/base/gsicc_manage.c
+++ b/base/gsicc_manage.c
@@ -1028,10 +1028,12 @@ gsicc_open_search(const char* pname, int namelen, gs_memory_t *mem_gc,
}
/* First just try it like it is */
- str = sfopen(pname, "rb", mem_gc);
- if (str != NULL) {
- *strp = str;
- return 0;
+ if (gs_check_file_permission(mem_gc, pname, namelen, "r") >= 0) {
+ str = sfopen(pname, "rb", mem_gc);
+ if (str != NULL) {
+ *strp = str;
+ return 0;
+ }
}
/* If that fails, try %rom% */ /* FIXME: Not sure this is needed or correct */
diff --git a/base/gslibctx.c b/base/gslibctx.c
index eaa0458..37ce1ca 100644
--- a/base/gslibctx.c
+++ b/base/gslibctx.c
@@ -121,7 +121,7 @@ int gs_lib_ctx_init( gs_memory_t *mem )
mem->gs_lib_ctx = NULL;
return -1;
}
-
+ pio->client_check_file_permission = NULL;
gp_get_realtime(pio->real_time_0);
return 0;
@@ -262,3 +262,13 @@ void errflush(const gs_memory_t *mem)
fflush(mem->gs_lib_ctx->fstderr);
/* else nothing to flush */
}
+
+int
+gs_check_file_permission (gs_memory_t *mem, const char *fname, const int len, const char *permission)
+{
+ int code = 0;
+ if (mem->gs_lib_ctx->client_check_file_permission != NULL) {
+ code = mem->gs_lib_ctx->client_check_file_permission(mem, fname, len, permission);
+ }
+ return code;
+}
diff --git a/base/gslibctx.h b/base/gslibctx.h
index 7a4e110..020e2d9 100644
--- a/base/gslibctx.h
+++ b/base/gslibctx.h
@@ -32,6 +32,9 @@ typedef struct gs_fapi_server_s gs_fapi_server;
# define gs_font_dir_DEFINED
typedef struct gs_font_dir_s gs_font_dir;
#endif
+
+typedef int (*client_check_file_permission_t) (gs_memory_t *mem, const char *fname, const int len, const char *permission);
+
typedef struct gs_lib_ctx_s
{
gs_memory_t *memory; /* mem->gs_lib_ctx->memory == mem */
@@ -59,6 +62,7 @@ typedef struct gs_lib_ctx_s
bool dict_auto_expand; /* ps dictionary: false level 1 true level 2 or 3 */
/* A table of local copies of the IODevices */
struct gx_io_device_s **io_device_table;
+ client_check_file_permission_t client_check_file_permission;
/* Define the default value of AccurateScreens that affects setscreen
and setcolorscreen. */
bool screen_accurate_screens;
@@ -108,6 +112,9 @@ int
void gs_lib_ctx_set_icc_directory(const gs_memory_t *mem_gc, const char* pname,
int dir_namelen);
+int
+gs_check_file_permission (gs_memory_t *mem, const char *fname, const int len, const char *permission);
+
#define IS_LIBCTX_STDOUT(mem, f) (f == mem->gs_lib_ctx->fstdout)
#define IS_LIBCTX_STDERR(mem, f) (f == mem->gs_lib_ctx->fstderr)
diff --git a/psi/imain.c b/psi/imain.c
index 9a9bb5d..6874128 100644
--- a/psi/imain.c
+++ b/psi/imain.c
@@ -57,6 +57,7 @@
#include "ivmspace.h"
#include "idisp.h" /* for setting display device callback */
#include "iplugin.h"
+#include "zfile.h"
#ifdef PACIFY_VALGRIND
#include "valgrind.h"
@@ -215,6 +216,7 @@ gs_main_init1(gs_main_instance * minst)
"the_gs_name_table");
if (code < 0)
return code;
+ mem->gs_lib_ctx->client_check_file_permission = z_check_file_permissions;
}
code = obj_init(&minst->i_ctx_p, &idmem); /* requires name_init */
if (code < 0)
diff --git a/psi/int.mak b/psi/int.mak
index 4654afc..bb30d51 100644
--- a/psi/int.mak
+++ b/psi/int.mak
@@ -1868,7 +1868,7 @@ $(PSOBJ)imain.$(OBJ) : $(PSSRC)imain.c $(GH) $(memory__h) $(string__h)\
$(ialloc_h) $(iconf_h) $(idebug_h) $(idict_h) $(idisp_h) $(iinit_h)\
$(iname_h) $(interp_h) $(iplugin_h) $(isave_h) $(iscan_h) $(ivmspace_h)\
$(iinit_h) $(main_h) $(oper_h) $(ostack_h)\
- $(sfilter_h) $(store_h) $(stream_h) $(strimpl_h)
+ $(sfilter_h) $(store_h) $(stream_h) $(strimpl_h) $(zfile_h)
$(PSCC) $(PSO_)imain.$(OBJ) $(C_) $(PSSRC)imain.c
#****** $(CCINT) interp.c
diff --git a/psi/zfile.c b/psi/zfile.c
index 2c6c958..2f27f82 100644
--- a/psi/zfile.c
+++ b/psi/zfile.c
@@ -197,6 +197,25 @@ check_file_permissions(i_ctx_t *i_ctx_p, const char *fname, int len,
return check_file_permissions_reduced(i_ctx_p, fname_reduced, rlen, permitgroup);
}
+/* z_check_file_permissions: see zfile.h for explanation
+ */
+int
+z_check_file_permissions(gs_memory_t *mem, const char *fname, const int len, const char *permission)
+{
+ i_ctx_t *i_ctx_p = get_minst_from_memory(mem)->i_ctx_p;
+ gs_parsed_file_name_t pname;
+ const char *permitgroup = permission[0] == 'r' ? "PermitFileReading" : "PermitFileWriting";
+ int code = gs_parse_file_name(&pname, fname, len, imemory);
+ if (code < 0)
+ return code;
+
+ if (pname.iodev && i_ctx_p->LockFilePermissions && strcmp(pname.iodev->dname, "%pipe%") == 0)
+ return e_invalidfileaccess;
+
+ code = check_file_permissions(i_ctx_p, fname, len, permitgroup);
+ return code;
+}
+
/* <name_string> <access_string> file <file> */
int /* exported for zsysvm.c */
zfile(i_ctx_t *i_ctx_p)
diff --git a/psi/zfile.h b/psi/zfile.h
index fdf1373..a9399c7 100644
--- a/psi/zfile.h
+++ b/psi/zfile.h
@@ -22,4 +22,11 @@
int zopen_file(i_ctx_t *i_ctx_p, const gs_parsed_file_name_t *pfn,
const char *file_access, stream **ps, gs_memory_t *mem);
+/* z_check_file_permissions: a callback (via mem->gs_lib_ctx->client_check_file_permission)
+ * to allow applying the above permissions checks when opening file(s) from
+ * the graphics library
+ */
+int
+z_check_file_permissions(gs_memory_t *mem, const char *fname,
+ const int len, const char *permission);
#endif
--
2.9.1
|