1 /*
2 * Copyright 2018-2022 The OpenSSL Project Authors. All Rights Reserved.
3 *
4 * Licensed under the Apache License 2.0 (the "License"). You may not use
5 * this file except in compliance with the License. You can obtain a copy
6 * in the file LICENSE in the source distribution or at
7 * https://www.openssl.org/source/license.html
8 */
9
10 #include <stdio.h>
11 #include <stdlib.h>
12 #include <string.h>
13 #include "testutil.h"
14 #include "internal/cryptlib.h"
15
16 #if (defined(__i386) || defined(__i386__) || defined(_M_IX86) || defined(__x86_64) || defined(__x86_64__) || defined(_M_AMD64) || defined(_M_X64)) && defined(OPENSSL_CPUID_OBJ)
17 #define IS_X_86 1
18 size_t OPENSSL_ia32_rdrand_bytes(unsigned char *buf, size_t len);
19 size_t OPENSSL_ia32_rdseed_bytes(unsigned char *buf, size_t len);
20 #else
21 #define IS_X_86 0
22 #endif
23
24 #if defined(__aarch64__) && defined(OPENSSL_CPUID_OBJ)
25 #define IS_AARCH_64 1
26 #include "arm_arch.h"
27
28 size_t OPENSSL_rndr_bytes(unsigned char *buf, size_t len);
29 size_t OPENSSL_rndrrs_bytes(unsigned char *buf, size_t len);
30 #else
31 #define IS_AARCH_64 0
32 #endif
33
34 #if (IS_X_86 || IS_AARCH_64)
sanity_check_bytes(size_t (* rng)(unsigned char *,size_t),int rounds,int min_failures,int max_retries,int max_zero_words)35 static int sanity_check_bytes(size_t (*rng)(unsigned char *, size_t),
36 int rounds, int min_failures, int max_retries, int max_zero_words)
37 {
38 int testresult = 0;
39 unsigned char prior[31] = { 0 }, buf[31] = { 0 }, check[7];
40 int failures = 0, zero_words = 0;
41
42 int i;
43 for (i = 0; i < rounds; i++) {
44 size_t generated = 0;
45
46 int retry;
47 for (retry = 0; retry < max_retries; retry++) {
48 generated = rng(buf, sizeof(buf));
49 if (generated == sizeof(buf))
50 break;
51 failures++;
52 }
53
54 /*-
55 * Verify that we don't have too many unexpected runs of zeroes,
56 * implying that we might be accidentally using the 32-bit RDRAND
57 * instead of the 64-bit one on 64-bit systems.
58 */
59 size_t j;
60 for (j = 0; j < sizeof(buf) - 1; j++) {
61 if (buf[j] == 0 && buf[j + 1] == 0) {
62 zero_words++;
63 }
64 }
65
66 if (!TEST_int_eq(generated, sizeof(buf)))
67 goto end;
68 if (!TEST_false(!memcmp(prior, buf, sizeof(buf))))
69 goto end;
70
71 /* Verify that the last 7 bytes of buf aren't all the same value */
72 unsigned char *tail = &buf[sizeof(buf) - sizeof(check)];
73 memset(check, tail[0], 7);
74 if (!TEST_false(!memcmp(check, tail, sizeof(check))))
75 goto end;
76
77 /* Save the result and make sure it's different next time */
78 memcpy(prior, buf, sizeof(buf));
79 }
80
81 if (!TEST_int_le(zero_words, max_zero_words))
82 goto end;
83
84 if (!TEST_int_ge(failures, min_failures))
85 goto end;
86
87 testresult = 1;
88 end:
89 return testresult;
90 }
91 #endif
92
93 #if IS_X_86
sanity_check_rdrand_bytes(void)94 static int sanity_check_rdrand_bytes(void)
95 {
96 return sanity_check_bytes(OPENSSL_ia32_rdrand_bytes, 1000, 0, 10, 10);
97 }
98
sanity_check_rdseed_bytes(void)99 static int sanity_check_rdseed_bytes(void)
100 {
101 /*-
102 * RDSEED may take many retries to succeed; note that this is effectively
103 * multiplied by the 8x retry loop in asm, and failure probabilities are
104 * increased by the fact that we need either 4 or 8 samples depending on
105 * the platform.
106 */
107 return sanity_check_bytes(OPENSSL_ia32_rdseed_bytes, 1000, 1, 10000, 10);
108 }
109 #elif IS_AARCH_64
sanity_check_rndr_bytes(void)110 static int sanity_check_rndr_bytes(void)
111 {
112 return sanity_check_bytes(OPENSSL_rndr_bytes, 1000, 0, 10, 10);
113 }
114
sanity_check_rndrrs_bytes(void)115 static int sanity_check_rndrrs_bytes(void)
116 {
117 return sanity_check_bytes(OPENSSL_rndrrs_bytes, 1000, 0, 10000, 10);
118 }
119 #endif
120
setup_tests(void)121 int setup_tests(void)
122 {
123 #if (IS_X_86 || IS_AARCH_64)
124 OPENSSL_cpuid_setup();
125
126 #if IS_X_86
127 int have_rdseed = (OPENSSL_ia32cap_P[2] & (1 << 18)) != 0;
128 int have_rdrand = (OPENSSL_ia32cap_P[1] & (1 << (62 - 32))) != 0;
129
130 if (have_rdrand) {
131 ADD_TEST(sanity_check_rdrand_bytes);
132 }
133
134 if (have_rdseed) {
135 ADD_TEST(sanity_check_rdseed_bytes);
136 }
137 #elif IS_AARCH_64
138 int have_rndr_rndrrs = (OPENSSL_armcap_P & (1 << 8)) != 0;
139
140 if (have_rndr_rndrrs) {
141 ADD_TEST(sanity_check_rndr_bytes);
142 ADD_TEST(sanity_check_rndrrs_bytes);
143 }
144 #endif
145 #endif
146
147 return 1;
148 }
149