1 /*
2 * Copyright (c) 2020 Apple Inc. All rights reserved.
3 *
4 * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
5 *
6 * This file contains Original Code and/or Modifications of Original Code
7 * as defined in and that are subject to the Apple Public Source License
8 * Version 2.0 (the 'License'). You may not use this file except in
9 * compliance with the License. The rights granted to you under the License
10 * may not be used to create, or enable the creation or redistribution of,
11 * unlawful or unlicensed copies of an Apple operating system, or to
12 * circumvent, violate, or enable the circumvention or violation of, any
13 * terms of an Apple operating system software license agreement.
14 *
15 * Please obtain a copy of the License at
16 * http://www.opensource.apple.com/apsl/ and read it before using this file.
17 *
18 * The Original Code and all software distributed under the License are
19 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
20 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
21 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
22 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
23 * Please see the License for the specific language governing rights and
24 * limitations under the License.
25 *
26 * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
27 */
28
29 #if DEVELOPMENT || DEBUG
30 #if __has_feature(ptrauth_calls)
31
32 #include <pexpert/pexpert.h>
33 #include <mach/port.h>
34 #include <mach/task.h>
35 #include <kern/task.h>
36 #include <vm/vm_map_xnu.h>
37 #include <vm/pmap.h>
38 #include <ipc/ipc_types.h>
39 #include <ipc/ipc_port.h>
40 #include <ipc/ipc_space.h>
41 #include <kern/ipc_kobject.h>
42 #include <kern/kern_types.h>
43 #include <libkern/ptrauth_utils.h>
44
45 kern_return_t ptrauth_data_tests(void);
46
47 /*
48 * Given an existing PAC pointer (ptr), its declaration type (decl), the (key)
49 * used to sign it and the string discriminator (discr), extract the raw pointer
50 * along with the signature and compare it with one computed on the fly
51 * via ptrauth_sign_unauthenticated().
52 *
53 * If the two mismatch, return an error and fail the test.
54 */
55 #define VALIDATE_PTR(decl, ptr, key, discr) { \
56 decl raw = *(decl *)&(ptr); \
57 decl cmp = ptrauth_sign_unauthenticated(ptr, key, \
58 ptrauth_blend_discriminator(&ptr, ptrauth_string_discriminator(discr))); \
59 if (cmp != raw) { \
60 printf("kern.run_pac_test: %s (%s) (discr=%s) is not signed as expected (%p vs %p)\n", #decl, #ptr, #discr, raw, cmp); \
61 kr = KERN_INVALID_ADDRESS; \
62 } \
63 }
64
65 /*
66 * Allocate the containing structure, and store a pointer to the desired member,
67 * which should be subject to pointer signing.
68 */
69 #define ALLOC_VALIDATE_DATA_PTR(structure, decl, member, discr) { \
70 __typed_allocators_ignore_push \
71 structure *tmp = kalloc_data(sizeof(structure), Z_WAITOK | Z_ZERO); \
72 if (!tmp) return KERN_NO_SPACE; \
73 tmp->member = (void*)0xffffffff41414141; \
74 VALIDATE_DATA_PTR(decl, tmp->member, discr) \
75 kfree_data(tmp, sizeof(structure)); \
76 __typed_allocators_ignore_pop \
77 }
78
79 #define VALIDATE_DATA_PTR(decl, ptr, discr) VALIDATE_PTR(decl, ptr, ptrauth_key_process_independent_data, discr)
80
81 /*
82 * Regression test for rdar://103054854
83 */
84 #define PTRAUTH_DATA_BLOB_TESTS(void) { \
85 unsigned char a[] = { 0x41, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 }; \
86 unsigned char b[] = { 0x41, 0x41, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 }; \
87 if (ptrauth_utils_sign_blob_generic(a, 1, 0, 0) != ptrauth_utils_sign_blob_generic(b, 1, 0, 0)) { \
88 printf("kern.run_pac_test: ptrauth_data_blob_tests: mismatched blob signatures\n"); \
89 kr = KERN_FAILURE; \
90 } \
91 }
92
93 /*
94 * Validate that a pointer that is supposed to be signed, is, and that the signature
95 * matches based on signing key, location and discriminator
96 */
97 kern_return_t
ptrauth_data_tests(void)98 ptrauth_data_tests(void)
99 {
100 int kr = KERN_SUCCESS;
101
102 /* task_t */
103 ALLOC_VALIDATE_DATA_PTR(struct task, vm_map_t, map, "task.map");
104 ALLOC_VALIDATE_DATA_PTR(struct task, struct ipc_port *, itk_task_ports[0], "task.itk_task_ports");
105 #if CONFIG_CSR
106 ALLOC_VALIDATE_DATA_PTR(struct task, struct ipc_port *, itk_settable_self, "task.itk_settable_self");
107 #endif /* CONFIG_CSR */
108 ALLOC_VALIDATE_DATA_PTR(struct task, struct ipc_port *, itk_host, "task.itk_host");
109 ALLOC_VALIDATE_DATA_PTR(struct task, struct ipc_port *, itk_bootstrap, "task.itk_bootstrap");
110 ALLOC_VALIDATE_DATA_PTR(struct task, struct ipc_port *, itk_debug_control, "task.itk_debug_control");
111 ALLOC_VALIDATE_DATA_PTR(struct task, struct ipc_space *, itk_space, "task.itk_space");
112 ALLOC_VALIDATE_DATA_PTR(struct task, struct ipc_port *, itk_task_access, "task.itk_task_access");
113 ALLOC_VALIDATE_DATA_PTR(struct task, struct ipc_port *, itk_resume, "task.itk_resume");
114
115 /* _vm_map */
116 ALLOC_VALIDATE_DATA_PTR(struct _vm_map, pmap_t, pmap, "_vm_map.pmap");
117
118 /* ipc_kobject_label */
119 ALLOC_VALIDATE_DATA_PTR(struct ipc_kobject_label, ipc_kobject_t, ikol_alt_port, "ipc_kobject_label.ikol_alt_port");
120
121 /* ipc_entry */
122 ALLOC_VALIDATE_DATA_PTR(struct ipc_entry, struct ipc_object *, ie_object, "ipc_entry.ie_object");
123
124 /* ipc_kmsg */
125 ALLOC_VALIDATE_DATA_PTR(struct ipc_kmsg, void *, ikm_udata, "kmsg.ikm_udata");
126 ALLOC_VALIDATE_DATA_PTR(struct ipc_kmsg, struct ipc_port *, ikm_voucher_port, "kmsg.ikm_voucher_port");
127
128 PTRAUTH_DATA_BLOB_TESTS();
129 return kr;
130 }
131
132 #endif /* __has_feature(ptrauth_calls) */
133 #endif /* DEVELOPMENT || DEBUG */
134