1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3 * efi_selftest_rng
4 *
5 * Copyright (c) 2019 Heinrich Schuchardt <xypron.glpk@gmx.de>
6 *
7 * Test the random number generator service.
8 */
9
10 #include <efi_selftest.h>
11 #include <efi_rng.h>
12
13 #define RNG_LEN 9
14
15 static struct efi_boot_services *boottime;
16 static efi_guid_t efi_rng_guid = EFI_RNG_PROTOCOL_GUID;
17
18 /*
19 * Setup unit test.
20 *
21 * @handle: handle of the loaded image
22 * @systable: system table
23 * @return: EFI_ST_SUCCESS for success
24 */
setup(const efi_handle_t handle,const struct efi_system_table * systable)25 static int setup(const efi_handle_t handle,
26 const struct efi_system_table *systable)
27 {
28 boottime = systable->boottime;
29 return EFI_ST_SUCCESS;
30 }
31
32 /*
33 * Execute unit test.
34 *
35 * Retrieve available RNG algorithms.
36 * Retrieve two random values and compare them.
37 *
38 * @return: EFI_ST_SUCCESS for success
39 */
execute(void)40 static int execute(void)
41 {
42 efi_status_t ret;
43 efi_uintn_t size;
44 struct efi_rng_protocol *rng;
45 efi_guid_t *algo_list;
46 u8 rnd1[RNG_LEN] __aligned(4), rnd2[RNG_LEN] __aligned(4);
47 int r;
48
49 /* Get random number generator protocol */
50 ret = boottime->locate_protocol(&efi_rng_guid, NULL, (void **)&rng);
51 if (ret != EFI_SUCCESS) {
52 efi_st_error(
53 "Random number generator protocol not available\n");
54 return EFI_ST_FAILURE;
55 }
56
57 ret = rng->get_info(rng, &size, NULL);
58 if (ret != EFI_BUFFER_TOO_SMALL) {
59 efi_st_error("Could not retrieve alorithm list size\n");
60 return EFI_ST_FAILURE;
61 }
62 if (size < sizeof(efi_guid_t)) {
63 efi_st_error("Empty alorithm list\n");
64 return EFI_ST_FAILURE;
65 }
66
67 ret = boottime->allocate_pool(EFI_LOADER_DATA, size,
68 (void **)&algo_list);
69 if (ret != EFI_SUCCESS) {
70 efi_st_error("Could not allocate pool memory\n");
71 return EFI_ST_FAILURE;
72 }
73
74 ret = rng->get_info(rng, &size, algo_list);
75 if (ret != EFI_SUCCESS) {
76 efi_st_error("Could not get info\n");
77 return EFI_ST_FAILURE;
78 }
79 if (size < sizeof(efi_guid_t)) {
80 efi_st_error("Empty alorithm list\n");
81 return EFI_ST_FAILURE;
82 }
83
84 memset(rnd1, 0, RNG_LEN);
85 memset(rnd2, 0, RNG_LEN);
86
87 ret = rng->get_rng(rng, NULL, RNG_LEN - 1, &rnd1[1]);
88 if (ret != EFI_SUCCESS) {
89 efi_st_error("Could not get random value\n");
90 return EFI_ST_FAILURE;
91 }
92 ret = rng->get_rng(rng, algo_list, RNG_LEN - 1, &rnd2[1]);
93 if (ret != EFI_SUCCESS) {
94 efi_st_error("Could not get random value\n");
95 return EFI_ST_FAILURE;
96 }
97 r = memcmp(rnd1, rnd2, RNG_LEN);
98 if (!r) {
99 efi_st_error("Two equal consecutive random numbers\n");
100 return EFI_ST_FAILURE;
101 }
102
103 ret = boottime->free_pool(algo_list);
104 if (ret != EFI_SUCCESS) {
105 efi_st_error("Could not free pool memory\n");
106 return EFI_ST_FAILURE;
107 }
108
109 return EFI_ST_SUCCESS;
110 }
111
112 EFI_UNIT_TEST(rng) = {
113 .name = "random number generator",
114 .phase = EFI_EXECUTE_BEFORE_BOOTTIME_EXIT,
115 .setup = setup,
116 .execute = execute,
117 };
118