Home | History | Annotate | Line # | Download | only in test 
      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