748eb991f4
Calling the functions rand_pool_add_{additional,nonce}_data()
in crypto/rand/rand_lib.c with no implementation for djgpp/MSDOS
causees unresolved symbols when linking with djgpp.
Reported and fixed by Gisle Vanem
Reviewed-by: Rich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/6421)
516 lines
15 KiB
C
516 lines
15 KiB
C
/*
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* Copyright 1995-2018 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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#define _GNU_SOURCE
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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 "rand_lcl.h"
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#include "internal/rand_int.h"
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#include <stdio.h>
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#include "internal/dso.h"
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#if defined(__linux)
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# include <sys/syscall.h>
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#endif
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#if defined(__FreeBSD__)
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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__) || defined(__NetBSD__)
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# include <sys/param.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 <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(__DJGPP__) */
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int syscall_random(void *buf, size_t buflen);
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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_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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# 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 size on success, 0 on failure.
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*/
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static size_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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* 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 (!ossl_assert(buflen % sizeof(long) == 0))
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return 0;
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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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return 0;
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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;
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if (sysctl(mib, 2, buf, &len, NULL, 0) == -1)
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return done;
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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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/*
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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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int syscall_random(void *buf, size_t buflen)
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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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# if defined(__GNUC__) && __GNUC__>=2 && defined(__ELF__)
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extern int getentropy(void *bufer, size_t length) __attribute__((weak));
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if (getentropy != NULL)
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return getentropy(buf, buflen) == 0 ? buflen : 0;
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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 ? buflen : 0;
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# endif
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/* Linux supports this since version 3.17 */
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# if defined(__linux) && defined(SYS_getrandom)
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return (int)syscall(SYS_getrandom, buf, buflen, 0);
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# endif
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# if (defined(__FreeBSD__) || defined(__NetBSD__)) && defined(KERN_ARND)
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return (int)sysctl_random(buf, buflen);
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# endif
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return -1;
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}
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/*
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* Try the various seeding methods in turn, exit when successful.
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*
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* TODO(DRBG): If more than one entropy source is available, is it
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* preferable to stop as soon as enough entropy has been collected
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* (as favored by @rsalz) or should one rather be defensive and add
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* more entropy than requested and/or from different sources?
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*
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* Currently, the user can select multiple entropy sources in the
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* configure step, yet in practice only the first available source
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* will be used. A more flexible solution has been requested, but
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* currently it is not clear how this can be achieved without
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* overengineering the problem. There are many parameters which
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* could be taken into account when selecting the order and amount
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* of input from the different entropy sources (trust, quality,
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* possibility of blocking).
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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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# ifdef OPENSSL_RAND_SEED_NONE
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return rand_pool_entropy_available(pool);
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# else
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size_t bytes_needed;
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size_t entropy_available = 0;
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unsigned char *buffer;
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# ifdef OPENSSL_RAND_SEED_GETRANDOM
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bytes_needed = rand_pool_bytes_needed(pool, 1 /*entropy_factor*/);
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buffer = rand_pool_add_begin(pool, bytes_needed);
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if (buffer != NULL) {
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size_t bytes = 0;
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if (syscall_random(buffer, bytes_needed) == (int)bytes_needed)
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bytes = bytes_needed;
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rand_pool_add_end(pool, bytes, 8 * bytes);
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entropy_available = rand_pool_entropy_available(pool);
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}
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if (entropy_available > 0)
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return entropy_available;
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# endif
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# if defined(OPENSSL_RAND_SEED_LIBRANDOM)
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{
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/* Not yet implemented. */
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}
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# endif
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# ifdef OPENSSL_RAND_SEED_DEVRANDOM
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bytes_needed = rand_pool_bytes_needed(pool, 1 /*entropy_factor*/);
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if (bytes_needed > 0) {
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static const char *paths[] = { DEVRANDOM, NULL };
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FILE *fp;
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int i;
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for (i = 0; paths[i] != NULL; i++) {
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if ((fp = fopen(paths[i], "rb")) == NULL)
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continue;
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setbuf(fp, NULL);
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buffer = rand_pool_add_begin(pool, bytes_needed);
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if (buffer != NULL) {
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size_t bytes = 0;
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if (fread(buffer, 1, bytes_needed, fp) == bytes_needed)
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bytes = bytes_needed;
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rand_pool_add_end(pool, bytes, 8 * bytes);
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entropy_available = rand_pool_entropy_available(pool);
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}
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fclose(fp);
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if (entropy_available > 0)
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return entropy_available;
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bytes_needed = rand_pool_bytes_needed(pool, 1 /*entropy_factor*/);
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}
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}
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# endif
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# ifdef OPENSSL_RAND_SEED_RDTSC
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entropy_available = rand_acquire_entropy_from_tsc(pool);
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if (entropy_available > 0)
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return entropy_available;
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# endif
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# ifdef OPENSSL_RAND_SEED_RDCPU
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entropy_available = rand_acquire_entropy_from_cpu(pool);
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if (entropy_available > 0)
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return entropy_available;
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# endif
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# ifdef OPENSSL_RAND_SEED_EGD
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bytes_needed = rand_pool_bytes_needed(pool, 1 /*entropy_factor*/);
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if (bytes_needed > 0) {
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static const char *paths[] = { DEVRANDOM_EGD, NULL };
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int i;
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for (i = 0; paths[i] != NULL; i++) {
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buffer = rand_pool_add_begin(pool, bytes_needed);
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if (buffer != NULL) {
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size_t bytes = 0;
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int num = RAND_query_egd_bytes(paths[i],
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buffer, (int)bytes_needed);
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if (num == (int)bytes_needed)
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bytes = bytes_needed;
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rand_pool_add_end(pool, bytes, 8 * bytes);
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entropy_available = rand_pool_entropy_available(pool);
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}
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if (entropy_available > 0)
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return entropy_available;
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}
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}
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# endif
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return rand_pool_entropy_available(pool);
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# endif
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}
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# endif
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#endif
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#if defined(OPENSSL_SYS_UNIX) || defined(__DJGPP__)
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int rand_pool_add_nonce_data(RAND_POOL *pool)
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{
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struct {
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pid_t pid;
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CRYPTO_THREAD_ID tid;
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uint64_t time;
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} data = { 0 };
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/*
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* Add process id, thread id, and a high resolution timestamp to
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* ensure that the nonce is unique whith high probability for
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* different process instances.
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*/
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data.pid = getpid();
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data.tid = CRYPTO_THREAD_get_current_id();
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data.time = get_time_stamp();
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return rand_pool_add(pool, (unsigned char *)&data, sizeof(data), 0);
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}
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int rand_pool_add_additional_data(RAND_POOL *pool)
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{
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struct {
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CRYPTO_THREAD_ID tid;
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uint64_t time;
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} data = { 0 };
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/*
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* Add some noise from the thread id and a high resolution timer.
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* The thread id adds a little randomness if the drbg is accessed
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* concurrently (which is the case for the <master> drbg).
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*/
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data.tid = CRYPTO_THREAD_get_current_id();
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data.time = get_timer_bits();
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return rand_pool_add(pool, (unsigned char *)&data, sizeof(data), 0);
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}
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/*
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* Get the current time with the highest possible resolution
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*
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* The time stamp is added to the nonce, so it is optimized for not repeating.
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* The current time is ideal for this purpose, provided the computer's clock
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* is synchronized.
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*/
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static uint64_t get_time_stamp(void)
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{
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# if defined(OSSL_POSIX_TIMER_OKAY)
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{
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struct timespec ts;
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if (clock_gettime(CLOCK_REALTIME, &ts) == 0)
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return TWO32TO64(ts.tv_sec, ts.tv_nsec);
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}
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# endif
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# if defined(__unix__) \
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|| (defined(_POSIX_C_SOURCE) && _POSIX_C_SOURCE >= 200112L)
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{
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struct timeval tv;
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if (gettimeofday(&tv, NULL) == 0)
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return TWO32TO64(tv.tv_sec, tv.tv_usec);
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}
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# endif
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return time(NULL);
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}
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/*
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* Get an arbitrary timer value of the highest possible resolution
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*
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* The timer value is added as random noise to the additional data,
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* which is not considered a trusted entropy sourec, so any result
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* is acceptable.
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*/
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static uint64_t get_timer_bits(void)
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{
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uint64_t res = OPENSSL_rdtsc();
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if (res != 0)
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return res;
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# if defined(__sun) || defined(__hpux)
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return gethrtime();
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# elif defined(_AIX)
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{
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timebasestruct_t t;
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read_wall_time(&t, TIMEBASE_SZ);
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return TWO32TO64(t.tb_high, t.tb_low);
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}
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# elif defined(OSSL_POSIX_TIMER_OKAY)
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{
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struct timespec ts;
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# ifdef CLOCK_BOOTTIME
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# define CLOCK_TYPE CLOCK_BOOTTIME
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# elif defined(_POSIX_MONOTONIC_CLOCK)
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# define CLOCK_TYPE CLOCK_MONOTONIC
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# else
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# define CLOCK_TYPE CLOCK_REALTIME
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# endif
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if (clock_gettime(CLOCK_TYPE, &ts) == 0)
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return TWO32TO64(ts.tv_sec, ts.tv_nsec);
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}
|
|
# 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(__DJGPP__) */
|