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883 lines
26 KiB
C
883 lines
26 KiB
C
/*
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* Copyright 1995-2021 The OpenSSL Project Authors. All Rights Reserved.
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*
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* Licensed under the OpenSSL license (the "License"). You may not use
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* this file except in compliance with the License. You can obtain a copy
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* in the file LICENSE in the source distribution or at
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* https://www.openssl.org/source/license.html
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*/
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#ifndef _GNU_SOURCE
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# define _GNU_SOURCE
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#endif
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#include "e_os.h"
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#include <stdio.h>
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#include "internal/cryptlib.h"
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#include <openssl/rand.h>
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#include <openssl/crypto.h>
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#include "rand_local.h"
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#include "crypto/rand.h"
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#include <stdio.h>
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#include "internal/dso.h"
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#ifdef __linux
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# include <sys/syscall.h>
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# ifdef DEVRANDOM_WAIT
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# include <sys/shm.h>
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# include <sys/utsname.h>
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# endif
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#endif
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#if (defined(__FreeBSD__) || defined(__NetBSD__)) && !defined(OPENSSL_SYS_UEFI)
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# include <sys/types.h>
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# include <sys/sysctl.h>
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# include <sys/param.h>
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#endif
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#if defined(__OpenBSD__)
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# include <sys/param.h>
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#endif
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#if defined(__APPLE__)
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# include <CommonCrypto/CommonRandom.h>
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#endif
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#if defined(OPENSSL_SYS_UNIX) || defined(__DJGPP__)
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# include <sys/types.h>
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# include <sys/stat.h>
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# include <fcntl.h>
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# include <unistd.h>
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# include <sys/time.h>
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static uint64_t get_time_stamp(void);
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static uint64_t get_timer_bits(void);
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/* Macro to convert two thirty two bit values into a sixty four bit one */
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# define TWO32TO64(a, b) ((((uint64_t)(a)) << 32) + (b))
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/*
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* Check for the existence and support of POSIX timers. The standard
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* says that the _POSIX_TIMERS macro will have a positive value if they
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* are available.
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*
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* However, we want an additional constraint: that the timer support does
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* not require an extra library dependency. Early versions of glibc
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* require -lrt to be specified on the link line to access the timers,
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* so this needs to be checked for.
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*
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* It is worse because some libraries define __GLIBC__ but don't
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* support the version testing macro (e.g. uClibc). This means
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* an extra check is needed.
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*
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* The final condition is:
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* "have posix timers and either not glibc or glibc without -lrt"
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*
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* The nested #if sequences are required to avoid using a parameterised
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* macro that might be undefined.
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*/
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# undef OSSL_POSIX_TIMER_OKAY
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# if defined(_POSIX_TIMERS) && _POSIX_TIMERS > 0
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# if defined(__GLIBC__)
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# if defined(__GLIBC_PREREQ)
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# if __GLIBC_PREREQ(2, 17)
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# define OSSL_POSIX_TIMER_OKAY
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# endif
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# endif
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# else
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# define OSSL_POSIX_TIMER_OKAY
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# endif
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# endif
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#endif /* (defined(OPENSSL_SYS_UNIX) && !defined(OPENSSL_SYS_VXWORKS))
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|| defined(__DJGPP__) */
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#if defined(OPENSSL_RAND_SEED_NONE)
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/* none means none. this simplifies the following logic */
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# undef OPENSSL_RAND_SEED_OS
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# undef OPENSSL_RAND_SEED_GETRANDOM
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# undef OPENSSL_RAND_SEED_LIBRANDOM
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# undef OPENSSL_RAND_SEED_DEVRANDOM
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# undef OPENSSL_RAND_SEED_RDTSC
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# undef OPENSSL_RAND_SEED_RDCPU
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# undef OPENSSL_RAND_SEED_EGD
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#endif
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#if (defined(OPENSSL_SYS_VXWORKS) || defined(OPENSSL_SYS_UEFI)) && \
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!defined(OPENSSL_RAND_SEED_NONE)
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# error "UEFI and VXWorks only support seeding NONE"
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#endif
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#if defined(OPENSSL_SYS_VXWORKS)
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/* empty implementation */
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int rand_pool_init(void)
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{
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return 1;
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}
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void rand_pool_cleanup(void)
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{
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}
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void rand_pool_keep_random_devices_open(int keep)
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{
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}
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size_t rand_pool_acquire_entropy(RAND_POOL *pool)
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{
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return rand_pool_entropy_available(pool);
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}
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#endif
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#if !(defined(OPENSSL_SYS_WINDOWS) || defined(OPENSSL_SYS_WIN32) \
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|| defined(OPENSSL_SYS_VMS) || defined(OPENSSL_SYS_VXWORKS) \
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|| defined(OPENSSL_SYS_UEFI))
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# if defined(OPENSSL_SYS_VOS)
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# ifndef OPENSSL_RAND_SEED_OS
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# error "Unsupported seeding method configured; must be os"
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# endif
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# if defined(OPENSSL_SYS_VOS_HPPA) && defined(OPENSSL_SYS_VOS_IA32)
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# error "Unsupported HP-PA and IA32 at the same time."
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# endif
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# if !defined(OPENSSL_SYS_VOS_HPPA) && !defined(OPENSSL_SYS_VOS_IA32)
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# error "Must have one of HP-PA or IA32"
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# endif
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/*
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* The following algorithm repeatedly samples the real-time clock (RTC) to
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* generate a sequence of unpredictable data. The algorithm relies upon the
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* uneven execution speed of the code (due to factors such as cache misses,
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* interrupts, bus activity, and scheduling) and upon the rather large
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* relative difference between the speed of the clock and the rate at which
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* it can be read. If it is ported to an environment where execution speed
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* is more constant or where the RTC ticks at a much slower rate, or the
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* clock can be read with fewer instructions, it is likely that the results
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* would be far more predictable. This should only be used for legacy
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* platforms.
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*
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* As a precaution, we assume only 2 bits of entropy per byte.
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*/
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size_t rand_pool_acquire_entropy(RAND_POOL *pool)
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{
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short int code;
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int i, k;
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size_t bytes_needed;
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struct timespec ts;
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unsigned char v;
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# ifdef OPENSSL_SYS_VOS_HPPA
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long duration;
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extern void s$sleep(long *_duration, short int *_code);
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# else
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long long duration;
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extern void s$sleep2(long long *_duration, short int *_code);
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# endif
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bytes_needed = rand_pool_bytes_needed(pool, 4 /*entropy_factor*/);
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for (i = 0; i < bytes_needed; i++) {
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/*
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* burn some cpu; hope for interrupts, cache collisions, bus
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* interference, etc.
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*/
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for (k = 0; k < 99; k++)
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ts.tv_nsec = random();
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# ifdef OPENSSL_SYS_VOS_HPPA
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/* sleep for 1/1024 of a second (976 us). */
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duration = 1;
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s$sleep(&duration, &code);
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# else
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/* sleep for 1/65536 of a second (15 us). */
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duration = 1;
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s$sleep2(&duration, &code);
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# endif
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/* Get wall clock time, take 8 bits. */
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clock_gettime(CLOCK_REALTIME, &ts);
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v = (unsigned char)(ts.tv_nsec & 0xFF);
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rand_pool_add(pool, arg, &v, sizeof(v) , 2);
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}
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return rand_pool_entropy_available(pool);
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}
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void rand_pool_cleanup(void)
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{
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}
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void rand_pool_keep_random_devices_open(int keep)
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{
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}
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# else
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# if defined(OPENSSL_RAND_SEED_EGD) && \
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(defined(OPENSSL_NO_EGD) || !defined(DEVRANDOM_EGD))
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# error "Seeding uses EGD but EGD is turned off or no device given"
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# endif
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# if defined(OPENSSL_RAND_SEED_DEVRANDOM) && !defined(DEVRANDOM)
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# error "Seeding uses urandom but DEVRANDOM is not configured"
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# endif
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# if defined(OPENSSL_RAND_SEED_OS)
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# if !defined(DEVRANDOM)
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# error "OS seeding requires DEVRANDOM to be configured"
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# endif
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# define OPENSSL_RAND_SEED_GETRANDOM
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# define OPENSSL_RAND_SEED_DEVRANDOM
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# endif
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# if defined(OPENSSL_RAND_SEED_LIBRANDOM)
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# error "librandom not (yet) supported"
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# endif
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# if (defined(__FreeBSD__) || defined(__NetBSD__)) && defined(KERN_ARND)
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/*
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* sysctl_random(): Use sysctl() to read a random number from the kernel
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* Returns the number of bytes returned in buf on success, -1 on failure.
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*/
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static ssize_t sysctl_random(char *buf, size_t buflen)
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{
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int mib[2];
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size_t done = 0;
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size_t len;
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/*
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* Note: sign conversion between size_t and ssize_t is safe even
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* without a range check, see comment in syscall_random()
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*/
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/*
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* On FreeBSD old implementations returned longs, newer versions support
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* variable sizes up to 256 byte. The code below would not work properly
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* when the sysctl returns long and we want to request something not a
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* multiple of longs, which should never be the case.
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*/
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#if defined(__FreeBSD__)
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if (!ossl_assert(buflen % sizeof(long) == 0)) {
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errno = EINVAL;
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return -1;
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}
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#endif
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/*
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* On NetBSD before 4.0 KERN_ARND was an alias for KERN_URND, and only
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* filled in an int, leaving the rest uninitialized. Since NetBSD 4.0
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* it returns a variable number of bytes with the current version supporting
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* up to 256 bytes.
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* Just return an error on older NetBSD versions.
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*/
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#if defined(__NetBSD__) && __NetBSD_Version__ < 400000000
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errno = ENOSYS;
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return -1;
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#endif
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mib[0] = CTL_KERN;
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mib[1] = KERN_ARND;
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do {
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len = buflen > 256 ? 256 : buflen;
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if (sysctl(mib, 2, buf, &len, NULL, 0) == -1)
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return done > 0 ? done : -1;
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done += len;
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buf += len;
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buflen -= len;
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} while (buflen > 0);
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return done;
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}
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# endif
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# if defined(OPENSSL_RAND_SEED_GETRANDOM)
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# if defined(__linux) && !defined(__NR_getrandom)
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# if defined(__arm__)
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# define __NR_getrandom (__NR_SYSCALL_BASE+384)
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# elif defined(__i386__)
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# define __NR_getrandom 355
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# elif defined(__x86_64__)
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# if defined(__ILP32__)
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# define __NR_getrandom (__X32_SYSCALL_BIT + 318)
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# else
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# define __NR_getrandom 318
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# endif
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# elif defined(__xtensa__)
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# define __NR_getrandom 338
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# elif defined(__s390__) || defined(__s390x__)
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# define __NR_getrandom 349
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# elif defined(__bfin__)
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# define __NR_getrandom 389
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# elif defined(__powerpc__)
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# define __NR_getrandom 359
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# elif defined(__mips__) || defined(__mips64)
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# if _MIPS_SIM == _MIPS_SIM_ABI32
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# define __NR_getrandom (__NR_Linux + 353)
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# elif _MIPS_SIM == _MIPS_SIM_ABI64
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# define __NR_getrandom (__NR_Linux + 313)
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# elif _MIPS_SIM == _MIPS_SIM_NABI32
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# define __NR_getrandom (__NR_Linux + 317)
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# endif
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# elif defined(__hppa__)
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# define __NR_getrandom (__NR_Linux + 339)
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# elif defined(__sparc__)
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# define __NR_getrandom 347
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# elif defined(__ia64__)
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# define __NR_getrandom 1339
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# elif defined(__alpha__)
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# define __NR_getrandom 511
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# elif defined(__sh__)
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# if defined(__SH5__)
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# define __NR_getrandom 373
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# else
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# define __NR_getrandom 384
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# endif
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# elif defined(__avr32__)
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# define __NR_getrandom 317
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# elif defined(__microblaze__)
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# define __NR_getrandom 385
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# elif defined(__m68k__)
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# define __NR_getrandom 352
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# elif defined(__cris__)
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# define __NR_getrandom 356
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# elif defined(__aarch64__)
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# define __NR_getrandom 278
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# else /* generic */
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# define __NR_getrandom 278
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# endif
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# endif
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/*
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* syscall_random(): Try to get random data using a system call
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* returns the number of bytes returned in buf, or < 0 on error.
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*/
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static ssize_t syscall_random(void *buf, size_t buflen)
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{
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/*
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* Note: 'buflen' equals the size of the buffer which is used by the
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* get_entropy() callback of the RAND_DRBG. It is roughly bounded by
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*
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* 2 * RAND_POOL_FACTOR * (RAND_DRBG_STRENGTH / 8) = 2^14
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*
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* which is way below the OSSL_SSIZE_MAX limit. Therefore sign conversion
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* between size_t and ssize_t is safe even without a range check.
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*/
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/*
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* Do runtime detection to find getentropy().
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*
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* Known OSs that should support this:
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* - Darwin since 16 (OSX 10.12, IOS 10.0).
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* - Solaris since 11.3
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* - OpenBSD since 5.6
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* - Linux since 3.17 with glibc 2.25
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* - FreeBSD since 12.0 (1200061)
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*
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* Note: Sometimes getentropy() can be provided but not implemented
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* internally. So we need to check errno for ENOSYS
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*/
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# if defined(__GNUC__) && __GNUC__>=2 && defined(__ELF__) && !defined(__hpux)
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extern int getentropy(void *buffer, size_t length) __attribute__((weak));
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if (getentropy != NULL) {
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if (getentropy(buf, buflen) == 0)
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return (ssize_t)buflen;
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if (errno != ENOSYS)
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return -1;
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}
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# elif defined(__APPLE__)
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if (CCRandomGenerateBytes(buf, buflen) == kCCSuccess)
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return (ssize_t)buflen;
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return -1;
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# else
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union {
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void *p;
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int (*f)(void *buffer, size_t length);
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} p_getentropy;
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/*
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* We could cache the result of the lookup, but we normally don't
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* call this function often.
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*/
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ERR_set_mark();
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p_getentropy.p = DSO_global_lookup("getentropy");
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ERR_pop_to_mark();
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if (p_getentropy.p != NULL)
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return p_getentropy.f(buf, buflen) == 0 ? (ssize_t)buflen : -1;
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# endif
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/* Linux supports this since version 3.17 */
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# if defined(__linux) && defined(__NR_getrandom)
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return syscall(__NR_getrandom, buf, buflen, 0);
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# elif (defined(__FreeBSD__) || defined(__NetBSD__)) && defined(KERN_ARND)
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return sysctl_random(buf, buflen);
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# else
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errno = ENOSYS;
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return -1;
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# endif
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}
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# endif /* defined(OPENSSL_RAND_SEED_GETRANDOM) */
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# if defined(OPENSSL_RAND_SEED_DEVRANDOM)
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static const char *random_device_paths[] = { DEVRANDOM };
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static struct random_device {
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int fd;
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dev_t dev;
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ino_t ino;
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mode_t mode;
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dev_t rdev;
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} random_devices[OSSL_NELEM(random_device_paths)];
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static int keep_random_devices_open = 1;
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# if defined(__linux) && defined(DEVRANDOM_WAIT) \
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&& defined(OPENSSL_RAND_SEED_GETRANDOM)
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static void *shm_addr;
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static void cleanup_shm(void)
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{
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shmdt(shm_addr);
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}
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/*
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* Ensure that the system randomness source has been adequately seeded.
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* This is done by having the first start of libcrypto, wait until the device
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* /dev/random becomes able to supply a byte of entropy. Subsequent starts
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* of the library and later reseedings do not need to do this.
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*/
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static int wait_random_seeded(void)
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{
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static int seeded = OPENSSL_RAND_SEED_DEVRANDOM_SHM_ID < 0;
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static const int kernel_version[] = { DEVRANDOM_SAFE_KERNEL };
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int kernel[2];
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int shm_id, fd, r;
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char c, *p;
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struct utsname un;
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fd_set fds;
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if (!seeded) {
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/* See if anything has created the global seeded indication */
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if ((shm_id = shmget(OPENSSL_RAND_SEED_DEVRANDOM_SHM_ID, 1, 0)) == -1) {
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/*
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* Check the kernel's version and fail if it is too recent.
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*
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* Linux kernels from 4.8 onwards do not guarantee that
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* /dev/urandom is properly seeded when /dev/random becomes
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* readable. However, such kernels support the getentropy(2)
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* system call and this should always succeed which renders
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* this alternative but essentially identical source moot.
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*/
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if (uname(&un) == 0) {
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kernel[0] = atoi(un.release);
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p = strchr(un.release, '.');
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kernel[1] = p == NULL ? 0 : atoi(p + 1);
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if (kernel[0] > kernel_version[0]
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|| (kernel[0] == kernel_version[0]
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&& kernel[1] >= kernel_version[1])) {
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return 0;
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}
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}
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/* Open /dev/random and wait for it to be readable */
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if ((fd = open(DEVRANDOM_WAIT, O_RDONLY)) != -1) {
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if (DEVRANDM_WAIT_USE_SELECT && fd < FD_SETSIZE) {
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FD_ZERO(&fds);
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FD_SET(fd, &fds);
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while ((r = select(fd + 1, &fds, NULL, NULL, NULL)) < 0
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&& errno == EINTR);
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} else {
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while ((r = read(fd, &c, 1)) < 0 && errno == EINTR);
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}
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close(fd);
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if (r == 1) {
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seeded = 1;
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/* Create the shared memory indicator */
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shm_id = shmget(OPENSSL_RAND_SEED_DEVRANDOM_SHM_ID, 1,
|
|
IPC_CREAT | S_IRUSR | S_IRGRP | S_IROTH);
|
|
}
|
|
}
|
|
}
|
|
if (shm_id != -1) {
|
|
seeded = 1;
|
|
/*
|
|
* Map the shared memory to prevent its premature destruction.
|
|
* If this call fails, it isn't a big problem.
|
|
*/
|
|
shm_addr = shmat(shm_id, NULL, SHM_RDONLY);
|
|
if (shm_addr != (void *)-1)
|
|
OPENSSL_atexit(&cleanup_shm);
|
|
}
|
|
}
|
|
return seeded;
|
|
}
|
|
# else /* defined __linux && DEVRANDOM_WAIT && OPENSSL_RAND_SEED_GETRANDOM */
|
|
static int wait_random_seeded(void)
|
|
{
|
|
return 1;
|
|
}
|
|
# endif
|
|
|
|
/*
|
|
* Verify that the file descriptor associated with the random source is
|
|
* still valid. The rationale for doing this is the fact that it is not
|
|
* uncommon for daemons to close all open file handles when daemonizing.
|
|
* So the handle might have been closed or even reused for opening
|
|
* another file.
|
|
*/
|
|
static int check_random_device(struct random_device * rd)
|
|
{
|
|
struct stat st;
|
|
|
|
return rd->fd != -1
|
|
&& fstat(rd->fd, &st) != -1
|
|
&& rd->dev == st.st_dev
|
|
&& rd->ino == st.st_ino
|
|
&& ((rd->mode ^ st.st_mode) & ~(S_IRWXU | S_IRWXG | S_IRWXO)) == 0
|
|
&& rd->rdev == st.st_rdev;
|
|
}
|
|
|
|
/*
|
|
* Open a random device if required and return its file descriptor or -1 on error
|
|
*/
|
|
static int get_random_device(size_t n)
|
|
{
|
|
struct stat st;
|
|
struct random_device * rd = &random_devices[n];
|
|
|
|
/* reuse existing file descriptor if it is (still) valid */
|
|
if (check_random_device(rd))
|
|
return rd->fd;
|
|
|
|
/* open the random device ... */
|
|
if ((rd->fd = open(random_device_paths[n], O_RDONLY)) == -1)
|
|
return rd->fd;
|
|
|
|
/* ... and cache its relevant stat(2) data */
|
|
if (fstat(rd->fd, &st) != -1) {
|
|
rd->dev = st.st_dev;
|
|
rd->ino = st.st_ino;
|
|
rd->mode = st.st_mode;
|
|
rd->rdev = st.st_rdev;
|
|
} else {
|
|
close(rd->fd);
|
|
rd->fd = -1;
|
|
}
|
|
|
|
return rd->fd;
|
|
}
|
|
|
|
/*
|
|
* Close a random device making sure it is a random device
|
|
*/
|
|
static void close_random_device(size_t n)
|
|
{
|
|
struct random_device * rd = &random_devices[n];
|
|
|
|
if (check_random_device(rd))
|
|
close(rd->fd);
|
|
rd->fd = -1;
|
|
}
|
|
|
|
int rand_pool_init(void)
|
|
{
|
|
size_t i;
|
|
|
|
for (i = 0; i < OSSL_NELEM(random_devices); i++)
|
|
random_devices[i].fd = -1;
|
|
|
|
return 1;
|
|
}
|
|
|
|
void rand_pool_cleanup(void)
|
|
{
|
|
size_t i;
|
|
|
|
for (i = 0; i < OSSL_NELEM(random_devices); i++)
|
|
close_random_device(i);
|
|
}
|
|
|
|
void rand_pool_keep_random_devices_open(int keep)
|
|
{
|
|
if (!keep)
|
|
rand_pool_cleanup();
|
|
|
|
keep_random_devices_open = keep;
|
|
}
|
|
|
|
# else /* !defined(OPENSSL_RAND_SEED_DEVRANDOM) */
|
|
|
|
int rand_pool_init(void)
|
|
{
|
|
return 1;
|
|
}
|
|
|
|
void rand_pool_cleanup(void)
|
|
{
|
|
}
|
|
|
|
void rand_pool_keep_random_devices_open(int keep)
|
|
{
|
|
}
|
|
|
|
# endif /* defined(OPENSSL_RAND_SEED_DEVRANDOM) */
|
|
|
|
/*
|
|
* Try the various seeding methods in turn, exit when successful.
|
|
*
|
|
* TODO(DRBG): If more than one entropy source is available, is it
|
|
* preferable to stop as soon as enough entropy has been collected
|
|
* (as favored by @rsalz) or should one rather be defensive and add
|
|
* more entropy than requested and/or from different sources?
|
|
*
|
|
* Currently, the user can select multiple entropy sources in the
|
|
* configure step, yet in practice only the first available source
|
|
* will be used. A more flexible solution has been requested, but
|
|
* currently it is not clear how this can be achieved without
|
|
* overengineering the problem. There are many parameters which
|
|
* could be taken into account when selecting the order and amount
|
|
* of input from the different entropy sources (trust, quality,
|
|
* possibility of blocking).
|
|
*/
|
|
size_t rand_pool_acquire_entropy(RAND_POOL *pool)
|
|
{
|
|
# if defined(OPENSSL_RAND_SEED_NONE)
|
|
return rand_pool_entropy_available(pool);
|
|
# else
|
|
size_t entropy_available;
|
|
|
|
# if defined(OPENSSL_RAND_SEED_GETRANDOM)
|
|
{
|
|
size_t bytes_needed;
|
|
unsigned char *buffer;
|
|
ssize_t bytes;
|
|
/* Maximum allowed number of consecutive unsuccessful attempts */
|
|
int attempts = 3;
|
|
|
|
bytes_needed = rand_pool_bytes_needed(pool, 1 /*entropy_factor*/);
|
|
while (bytes_needed != 0 && attempts-- > 0) {
|
|
buffer = rand_pool_add_begin(pool, bytes_needed);
|
|
bytes = syscall_random(buffer, bytes_needed);
|
|
if (bytes > 0) {
|
|
rand_pool_add_end(pool, bytes, 8 * bytes);
|
|
bytes_needed -= bytes;
|
|
attempts = 3; /* reset counter after successful attempt */
|
|
} else if (bytes < 0 && errno != EINTR) {
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
entropy_available = rand_pool_entropy_available(pool);
|
|
if (entropy_available > 0)
|
|
return entropy_available;
|
|
# endif
|
|
|
|
# if defined(OPENSSL_RAND_SEED_LIBRANDOM)
|
|
{
|
|
/* Not yet implemented. */
|
|
}
|
|
# endif
|
|
|
|
# if defined(OPENSSL_RAND_SEED_DEVRANDOM)
|
|
if (wait_random_seeded()) {
|
|
size_t bytes_needed;
|
|
unsigned char *buffer;
|
|
size_t i;
|
|
|
|
bytes_needed = rand_pool_bytes_needed(pool, 1 /*entropy_factor*/);
|
|
for (i = 0; bytes_needed > 0 && i < OSSL_NELEM(random_device_paths);
|
|
i++) {
|
|
ssize_t bytes = 0;
|
|
/* Maximum number of consecutive unsuccessful attempts */
|
|
int attempts = 3;
|
|
const int fd = get_random_device(i);
|
|
|
|
if (fd == -1)
|
|
continue;
|
|
|
|
while (bytes_needed != 0 && attempts-- > 0) {
|
|
buffer = rand_pool_add_begin(pool, bytes_needed);
|
|
bytes = read(fd, buffer, bytes_needed);
|
|
|
|
if (bytes > 0) {
|
|
rand_pool_add_end(pool, bytes, 8 * bytes);
|
|
bytes_needed -= bytes;
|
|
attempts = 3; /* reset counter on successful attempt */
|
|
} else if (bytes < 0 && errno != EINTR) {
|
|
break;
|
|
}
|
|
}
|
|
if (bytes < 0 || !keep_random_devices_open)
|
|
close_random_device(i);
|
|
|
|
bytes_needed = rand_pool_bytes_needed(pool, 1);
|
|
}
|
|
entropy_available = rand_pool_entropy_available(pool);
|
|
if (entropy_available > 0)
|
|
return entropy_available;
|
|
}
|
|
# endif
|
|
|
|
# if defined(OPENSSL_RAND_SEED_RDTSC)
|
|
entropy_available = rand_acquire_entropy_from_tsc(pool);
|
|
if (entropy_available > 0)
|
|
return entropy_available;
|
|
# endif
|
|
|
|
# if defined(OPENSSL_RAND_SEED_RDCPU)
|
|
entropy_available = rand_acquire_entropy_from_cpu(pool);
|
|
if (entropy_available > 0)
|
|
return entropy_available;
|
|
# endif
|
|
|
|
# if defined(OPENSSL_RAND_SEED_EGD)
|
|
{
|
|
static const char *paths[] = { DEVRANDOM_EGD, NULL };
|
|
size_t bytes_needed;
|
|
unsigned char *buffer;
|
|
int i;
|
|
|
|
bytes_needed = rand_pool_bytes_needed(pool, 1 /*entropy_factor*/);
|
|
for (i = 0; bytes_needed > 0 && paths[i] != NULL; i++) {
|
|
size_t bytes = 0;
|
|
int num;
|
|
|
|
buffer = rand_pool_add_begin(pool, bytes_needed);
|
|
num = RAND_query_egd_bytes(paths[i],
|
|
buffer, (int)bytes_needed);
|
|
if (num == (int)bytes_needed)
|
|
bytes = bytes_needed;
|
|
|
|
rand_pool_add_end(pool, bytes, 8 * bytes);
|
|
bytes_needed = rand_pool_bytes_needed(pool, 1);
|
|
}
|
|
entropy_available = rand_pool_entropy_available(pool);
|
|
if (entropy_available > 0)
|
|
return entropy_available;
|
|
}
|
|
# endif
|
|
|
|
return rand_pool_entropy_available(pool);
|
|
# endif
|
|
}
|
|
# endif
|
|
#endif
|
|
|
|
#if defined(OPENSSL_SYS_UNIX) || defined(__DJGPP__)
|
|
int rand_pool_add_nonce_data(RAND_POOL *pool)
|
|
{
|
|
struct {
|
|
pid_t pid;
|
|
CRYPTO_THREAD_ID tid;
|
|
uint64_t time;
|
|
} data = { 0 };
|
|
|
|
/*
|
|
* Add process id, thread id, and a high resolution timestamp to
|
|
* ensure that the nonce is unique with high probability for
|
|
* different process instances.
|
|
*/
|
|
data.pid = getpid();
|
|
data.tid = CRYPTO_THREAD_get_current_id();
|
|
data.time = get_time_stamp();
|
|
|
|
return rand_pool_add(pool, (unsigned char *)&data, sizeof(data), 0);
|
|
}
|
|
|
|
int rand_pool_add_additional_data(RAND_POOL *pool)
|
|
{
|
|
struct {
|
|
int fork_id;
|
|
CRYPTO_THREAD_ID tid;
|
|
uint64_t time;
|
|
} data = { 0 };
|
|
|
|
/*
|
|
* Add some noise from the thread id and a high resolution timer.
|
|
* The fork_id adds some extra fork-safety.
|
|
* The thread id adds a little randomness if the drbg is accessed
|
|
* concurrently (which is the case for the <master> drbg).
|
|
*/
|
|
data.fork_id = openssl_get_fork_id();
|
|
data.tid = CRYPTO_THREAD_get_current_id();
|
|
data.time = get_timer_bits();
|
|
|
|
return rand_pool_add(pool, (unsigned char *)&data, sizeof(data), 0);
|
|
}
|
|
|
|
|
|
/*
|
|
* Get the current time with the highest possible resolution
|
|
*
|
|
* The time stamp is added to the nonce, so it is optimized for not repeating.
|
|
* The current time is ideal for this purpose, provided the computer's clock
|
|
* is synchronized.
|
|
*/
|
|
static uint64_t get_time_stamp(void)
|
|
{
|
|
# if defined(OSSL_POSIX_TIMER_OKAY)
|
|
{
|
|
struct timespec ts;
|
|
|
|
if (clock_gettime(CLOCK_REALTIME, &ts) == 0)
|
|
return TWO32TO64(ts.tv_sec, ts.tv_nsec);
|
|
}
|
|
# endif
|
|
# if defined(__unix__) \
|
|
|| (defined(_POSIX_C_SOURCE) && _POSIX_C_SOURCE >= 200112L)
|
|
{
|
|
struct timeval tv;
|
|
|
|
if (gettimeofday(&tv, NULL) == 0)
|
|
return TWO32TO64(tv.tv_sec, tv.tv_usec);
|
|
}
|
|
# endif
|
|
return time(NULL);
|
|
}
|
|
|
|
/*
|
|
* Get an arbitrary timer value of the highest possible resolution
|
|
*
|
|
* The timer value is added as random noise to the additional data,
|
|
* which is not considered a trusted entropy sourec, so any result
|
|
* is acceptable.
|
|
*/
|
|
static uint64_t get_timer_bits(void)
|
|
{
|
|
uint64_t res = OPENSSL_rdtsc();
|
|
|
|
if (res != 0)
|
|
return res;
|
|
|
|
# if defined(__sun) || defined(__hpux)
|
|
return gethrtime();
|
|
# elif defined(_AIX)
|
|
{
|
|
timebasestruct_t t;
|
|
|
|
read_wall_time(&t, TIMEBASE_SZ);
|
|
return TWO32TO64(t.tb_high, t.tb_low);
|
|
}
|
|
# elif defined(OSSL_POSIX_TIMER_OKAY)
|
|
{
|
|
struct timespec ts;
|
|
|
|
# ifdef CLOCK_BOOTTIME
|
|
# define CLOCK_TYPE CLOCK_BOOTTIME
|
|
# elif defined(_POSIX_MONOTONIC_CLOCK)
|
|
# define CLOCK_TYPE CLOCK_MONOTONIC
|
|
# else
|
|
# define CLOCK_TYPE CLOCK_REALTIME
|
|
# endif
|
|
|
|
if (clock_gettime(CLOCK_TYPE, &ts) == 0)
|
|
return TWO32TO64(ts.tv_sec, ts.tv_nsec);
|
|
}
|
|
# endif
|
|
# if defined(__unix__) \
|
|
|| (defined(_POSIX_C_SOURCE) && _POSIX_C_SOURCE >= 200112L)
|
|
{
|
|
struct timeval tv;
|
|
|
|
if (gettimeofday(&tv, NULL) == 0)
|
|
return TWO32TO64(tv.tv_sec, tv.tv_usec);
|
|
}
|
|
# endif
|
|
return time(NULL);
|
|
}
|
|
#endif /* (defined(OPENSSL_SYS_UNIX) && !defined(OPENSSL_SYS_VXWORKS))
|
|
|| defined(__DJGPP__) */
|