1 /*
2 * Copyright (c) 2017 Intel Corporation.
3 *
4 * SPDX-License-Identifier: Apache-2.0
5 */
6 #include <zephyr/bluetooth/bluetooth.h>
7 #include <zephyr/drivers/entropy.h>
8 #include <zephyr/ztest.h>
9
10 /*
11 * @addtogroup t_entropy_api
12 * @{
13 * @defgroup t_entropy_get_entropy test_entropy_get_entropy
14 * @brief TestPurpose: verify Get entropy works
15 * @details
16 * - Test Steps
17 * -# Read random numbers from Entropy driver.
18 * -# Verify whether buffer overflow occurred or not.
19 * -# Verify whether buffer completely filled or not.
20 * - Expected Results
21 * -# Random number should be generated.
22 * @}
23 */
24
25 #define BUFFER_LENGTH 10
26 #define RECHECK_RANDOM_ENTROPY 0x10
27
28 #ifdef CONFIG_RANDOM_BUFFER_NOCACHED
29 __attribute__((__section__(".nocache")))
30 static uint8_t entropy_buffer[BUFFER_LENGTH] = {0};
31 #else
32 static uint8_t entropy_buffer[BUFFER_LENGTH] = {0};
33 #endif
34
random_entropy(const struct device * dev,char * buffer,char num)35 static int random_entropy(const struct device *dev, char *buffer, char num)
36 {
37 int ret, i;
38 int count = 0;
39
40 (void)memset(buffer, num, BUFFER_LENGTH);
41
42 /* The BUFFER_LENGTH-1 is used so the driver will not
43 * write the last byte of the buffer. If that last
44 * byte is not 0 on return it means the driver wrote
45 * outside the passed buffer, and that should never
46 * happen.
47 */
48 ret = entropy_get_entropy(dev, buffer, BUFFER_LENGTH - 1);
49 if (ret) {
50 TC_PRINT("Error: entropy_get_entropy failed: %d\n", ret);
51 return TC_FAIL;
52 }
53 if (buffer[BUFFER_LENGTH - 1] != num) {
54 TC_PRINT("Error: entropy_get_entropy buffer overflow\n");
55 return TC_FAIL;
56 }
57
58 for (i = 0; i < BUFFER_LENGTH - 1; i++) {
59 TC_PRINT(" 0x%02x\n", buffer[i]);
60 if (buffer[i] == num) {
61 count++;
62 }
63 }
64
65 if (count >= 2) {
66 return RECHECK_RANDOM_ENTROPY;
67 } else {
68 return TC_PASS;
69 }
70 }
71
72 /*
73 * Function invokes the get_entropy callback in driver
74 * to get the random data and fill to passed buffer
75 */
get_entropy(void)76 static int get_entropy(void)
77 {
78 const struct device *const dev = DEVICE_DT_GET(DT_CHOSEN(zephyr_entropy));
79 int ret;
80
81 if (!device_is_ready(dev)) {
82 TC_PRINT("error: random device not ready\n");
83 return TC_FAIL;
84 }
85
86 TC_PRINT("random device is %p, name is %s\n",
87 dev, dev->name);
88
89 ret = random_entropy(dev, entropy_buffer, 0);
90
91 /* Check whether 20% or more of buffer still filled with default
92 * value(0), if yes then recheck again by filling nonzero value(0xa5)
93 * to buffer. Recheck random_entropy and verify whether 20% or more
94 * of buffer filled with value(0xa5) or not.
95 */
96 if (ret == RECHECK_RANDOM_ENTROPY) {
97 ret = random_entropy(dev, entropy_buffer, 0xa5);
98 if (ret == RECHECK_RANDOM_ENTROPY) {
99 return TC_FAIL;
100 } else {
101 return ret;
102 }
103 }
104 return ret;
105 }
106
ZTEST(entropy_api,test_entropy_get_entropy)107 ZTEST(entropy_api, test_entropy_get_entropy)
108 {
109 zassert_true(get_entropy() == TC_PASS);
110 }
111
entropy_api_setup(void)112 void *entropy_api_setup(void)
113 {
114 #ifdef CONFIG_BT
115 bt_enable(NULL);
116 #endif /* CONFIG_BT */
117
118 return NULL;
119 }
120
121 ZTEST_SUITE(entropy_api, NULL, entropy_api_setup, NULL, NULL, NULL);
122
