1 /* 2 * Copyright 2018 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) || \ 17 defined(__x86_64) || defined(__x86_64__) || \ 18 defined(_M_AMD64) || defined (_M_X64)) && defined(OPENSSL_CPUID_OBJ) 19 20 size_t OPENSSL_ia32_rdrand_bytes(unsigned char *buf, size_t len); 21 size_t OPENSSL_ia32_rdseed_bytes(unsigned char *buf, size_t len); 22 23 static int sanity_check_bytes(size_t (*rng)(unsigned char *, size_t), 24 int rounds, int min_failures, int max_retries, int max_zero_words) 25 { 26 int testresult = 0; 27 unsigned char prior[31] = {0}, buf[31] = {0}, check[7]; 28 int failures = 0, zero_words = 0; 29 30 int i; 31 for (i = 0; i < rounds; i++) { 32 size_t generated = 0; 33 34 int retry; 35 for (retry = 0; retry < max_retries; retry++) { 36 generated = rng(buf, sizeof(buf)); 37 if (generated == sizeof(buf)) 38 break; 39 failures++; 40 } 41 42 /*- 43 * Verify that we don't have too many unexpected runs of zeroes, 44 * implying that we might be accidentally using the 32-bit RDRAND 45 * instead of the 64-bit one on 64-bit systems. 46 */ 47 size_t j; 48 for (j = 0; j < sizeof(buf) - 1; j++) { 49 if (buf[j] == 0 && buf[j+1] == 0) { 50 zero_words++; 51 } 52 } 53 54 if (!TEST_int_eq(generated, sizeof(buf))) 55 goto end; 56 if (!TEST_false(!memcmp(prior, buf, sizeof(buf)))) 57 goto end; 58 59 /* Verify that the last 7 bytes of buf aren't all the same value */ 60 unsigned char *tail = &buf[sizeof(buf) - sizeof(check)]; 61 memset(check, tail[0], 7); 62 if (!TEST_false(!memcmp(check, tail, sizeof(check)))) 63 goto end; 64 65 /* Save the result and make sure it's different next time */ 66 memcpy(prior, buf, sizeof(buf)); 67 } 68 69 if (!TEST_int_le(zero_words, max_zero_words)) 70 goto end; 71 72 if (!TEST_int_ge(failures, min_failures)) 73 goto end; 74 75 testresult = 1; 76 end: 77 return testresult; 78 } 79 80 static int sanity_check_rdrand_bytes(void) 81 { 82 return sanity_check_bytes(OPENSSL_ia32_rdrand_bytes, 1000, 0, 10, 10); 83 } 84 85 static int sanity_check_rdseed_bytes(void) 86 { 87 /*- 88 * RDSEED may take many retries to succeed; note that this is effectively 89 * multiplied by the 8x retry loop in asm, and failure probabilities are 90 * increased by the fact that we need either 4 or 8 samples depending on 91 * the platform. 92 */ 93 return sanity_check_bytes(OPENSSL_ia32_rdseed_bytes, 1000, 1, 10000, 10); 94 } 95 96 int setup_tests(void) 97 { 98 OPENSSL_cpuid_setup(); 99 100 int have_rdseed = (OPENSSL_ia32cap_P[2] & (1 << 18)) != 0; 101 int have_rdrand = (OPENSSL_ia32cap_P[1] & (1 << (62 - 32))) != 0; 102 103 if (have_rdrand) { 104 ADD_TEST(sanity_check_rdrand_bytes); 105 } 106 107 if (have_rdseed) { 108 ADD_TEST(sanity_check_rdseed_bytes); 109 } 110 111 return 1; 112 } 113 114 115 #else 116 117 int setup_tests(void) 118 { 119 return 1; 120 } 121 122 #endif 123