| /* |
| * Copyright 1995-2020 The OpenSSL Project Authors. All Rights Reserved. |
| * |
| * Licensed under the Apache License 2.0 (the "License"). You may not use |
| * this file except in compliance with the License. You can obtain a copy |
| * in the file LICENSE in the source distribution or at |
| * https://www.openssl.org/source/license.html |
| */ |
| |
| #ifndef _GNU_SOURCE |
| # define _GNU_SOURCE |
| #endif |
| #include "e_os.h" |
| #include <stdio.h> |
| #include "internal/cryptlib.h" |
| #include <openssl/rand.h> |
| #include <openssl/crypto.h> |
| #include "rand_local.h" |
| #include "crypto/rand.h" |
| #include <stdio.h> |
| #include "internal/dso.h" |
| |
| #ifdef __linux |
| # include <sys/syscall.h> |
| # ifdef DEVRANDOM_WAIT |
| # include <sys/shm.h> |
| # include <sys/utsname.h> |
| # endif |
| #endif |
| #if (defined(__FreeBSD__) || defined(__NetBSD__)) && !defined(OPENSSL_SYS_UEFI) |
| # include <sys/types.h> |
| # include <sys/sysctl.h> |
| # include <sys/param.h> |
| #endif |
| #if defined(__OpenBSD__) |
| # include <sys/param.h> |
| #endif |
| |
| #if (defined(OPENSSL_SYS_UNIX) && !defined(OPENSSL_SYS_VXWORKS)) \ |
| || defined(__DJGPP__) |
| # include <sys/types.h> |
| # include <sys/stat.h> |
| # include <fcntl.h> |
| # include <unistd.h> |
| # include <sys/time.h> |
| |
| static uint64_t get_time_stamp(void); |
| static uint64_t get_timer_bits(void); |
| |
| /* Macro to convert two thirty two bit values into a sixty four bit one */ |
| # define TWO32TO64(a, b) ((((uint64_t)(a)) << 32) + (b)) |
| |
| /* |
| * Check for the existence and support of POSIX timers. The standard |
| * says that the _POSIX_TIMERS macro will have a positive value if they |
| * are available. |
| * |
| * However, we want an additional constraint: that the timer support does |
| * not require an extra library dependency. Early versions of glibc |
| * require -lrt to be specified on the link line to access the timers, |
| * so this needs to be checked for. |
| * |
| * It is worse because some libraries define __GLIBC__ but don't |
| * support the version testing macro (e.g. uClibc). This means |
| * an extra check is needed. |
| * |
| * The final condition is: |
| * "have posix timers and either not glibc or glibc without -lrt" |
| * |
| * The nested #if sequences are required to avoid using a parameterised |
| * macro that might be undefined. |
| */ |
| # undef OSSL_POSIX_TIMER_OKAY |
| # if defined(_POSIX_TIMERS) && _POSIX_TIMERS > 0 |
| # if defined(__GLIBC__) |
| # if defined(__GLIBC_PREREQ) |
| # if __GLIBC_PREREQ(2, 17) |
| # define OSSL_POSIX_TIMER_OKAY |
| # endif |
| # endif |
| # else |
| # define OSSL_POSIX_TIMER_OKAY |
| # endif |
| # endif |
| #endif /* (defined(OPENSSL_SYS_UNIX) && !defined(OPENSSL_SYS_VXWORKS)) |
| || defined(__DJGPP__) */ |
| |
| #if defined(OPENSSL_RAND_SEED_NONE) |
| /* none means none. this simplifies the following logic */ |
| # undef OPENSSL_RAND_SEED_OS |
| # undef OPENSSL_RAND_SEED_GETRANDOM |
| # undef OPENSSL_RAND_SEED_LIBRANDOM |
| # undef OPENSSL_RAND_SEED_DEVRANDOM |
| # undef OPENSSL_RAND_SEED_RDTSC |
| # undef OPENSSL_RAND_SEED_RDCPU |
| # undef OPENSSL_RAND_SEED_EGD |
| #endif |
| |
| #if defined(OPENSSL_SYS_UEFI) && !defined(OPENSSL_RAND_SEED_NONE) |
| # error "UEFI only supports seeding NONE" |
| #endif |
| |
| #if !(defined(OPENSSL_SYS_WINDOWS) || defined(OPENSSL_SYS_WIN32) \ |
| || defined(OPENSSL_SYS_VMS) || defined(OPENSSL_SYS_VXWORKS) \ |
| || defined(OPENSSL_SYS_UEFI)) |
| |
| # if defined(OPENSSL_SYS_VOS) |
| |
| # ifndef OPENSSL_RAND_SEED_OS |
| # error "Unsupported seeding method configured; must be os" |
| # endif |
| |
| # if defined(OPENSSL_SYS_VOS_HPPA) && defined(OPENSSL_SYS_VOS_IA32) |
| # error "Unsupported HP-PA and IA32 at the same time." |
| # endif |
| # if !defined(OPENSSL_SYS_VOS_HPPA) && !defined(OPENSSL_SYS_VOS_IA32) |
| # error "Must have one of HP-PA or IA32" |
| # endif |
| |
| /* |
| * The following algorithm repeatedly samples the real-time clock (RTC) to |
| * generate a sequence of unpredictable data. The algorithm relies upon the |
| * uneven execution speed of the code (due to factors such as cache misses, |
| * interrupts, bus activity, and scheduling) and upon the rather large |
| * relative difference between the speed of the clock and the rate at which |
| * it can be read. If it is ported to an environment where execution speed |
| * is more constant or where the RTC ticks at a much slower rate, or the |
| * clock can be read with fewer instructions, it is likely that the results |
| * would be far more predictable. This should only be used for legacy |
| * platforms. |
| * |
| * As a precaution, we assume only 2 bits of entropy per byte. |
| */ |
| size_t rand_pool_acquire_entropy(RAND_POOL *pool) |
| { |
| short int code; |
| int i, k; |
| size_t bytes_needed; |
| struct timespec ts; |
| unsigned char v; |
| # ifdef OPENSSL_SYS_VOS_HPPA |
| long duration; |
| extern void s$sleep(long *_duration, short int *_code); |
| # else |
| long long duration; |
| extern void s$sleep2(long long *_duration, short int *_code); |
| # endif |
| |
| bytes_needed = rand_pool_bytes_needed(pool, 4 /*entropy_factor*/); |
| |
| for (i = 0; i < bytes_needed; i++) { |
| /* |
| * burn some cpu; hope for interrupts, cache collisions, bus |
| * interference, etc. |
| */ |
| for (k = 0; k < 99; k++) |
| ts.tv_nsec = random(); |
| |
| # ifdef OPENSSL_SYS_VOS_HPPA |
| /* sleep for 1/1024 of a second (976 us). */ |
| duration = 1; |
| s$sleep(&duration, &code); |
| # else |
| /* sleep for 1/65536 of a second (15 us). */ |
| duration = 1; |
| s$sleep2(&duration, &code); |
| # endif |
| |
| /* Get wall clock time, take 8 bits. */ |
| clock_gettime(CLOCK_REALTIME, &ts); |
| v = (unsigned char)(ts.tv_nsec & 0xFF); |
| rand_pool_add(pool, arg, &v, sizeof(v) , 2); |
| } |
| return rand_pool_entropy_available(pool); |
| } |
| |
| void rand_pool_cleanup(void) |
| { |
| } |
| |
| void rand_pool_keep_random_devices_open(int keep) |
| { |
| } |
| |
| # else |
| |
| # if defined(OPENSSL_RAND_SEED_EGD) && \ |
| (defined(OPENSSL_NO_EGD) || !defined(DEVRANDOM_EGD)) |
| # error "Seeding uses EGD but EGD is turned off or no device given" |
| # endif |
| |
| # if defined(OPENSSL_RAND_SEED_DEVRANDOM) && !defined(DEVRANDOM) |
| # error "Seeding uses urandom but DEVRANDOM is not configured" |
| # endif |
| |
| # if defined(OPENSSL_RAND_SEED_OS) |
| # if !defined(DEVRANDOM) |
| # error "OS seeding requires DEVRANDOM to be configured" |
| # endif |
| # define OPENSSL_RAND_SEED_GETRANDOM |
| # define OPENSSL_RAND_SEED_DEVRANDOM |
| # endif |
| |
| # if defined(OPENSSL_RAND_SEED_LIBRANDOM) |
| # error "librandom not (yet) supported" |
| # endif |
| |
| # if (defined(__FreeBSD__) || defined(__NetBSD__)) && defined(KERN_ARND) |
| /* |
| * sysctl_random(): Use sysctl() to read a random number from the kernel |
| * Returns the number of bytes returned in buf on success, -1 on failure. |
| */ |
| static ssize_t sysctl_random(char *buf, size_t buflen) |
| { |
| int mib[2]; |
| size_t done = 0; |
| size_t len; |
| |
| /* |
| * Note: sign conversion between size_t and ssize_t is safe even |
| * without a range check, see comment in syscall_random() |
| */ |
| |
| /* |
| * On FreeBSD old implementations returned longs, newer versions support |
| * variable sizes up to 256 byte. The code below would not work properly |
| * when the sysctl returns long and we want to request something not a |
| * multiple of longs, which should never be the case. |
| */ |
| #if defined(__FreeBSD__) |
| if (!ossl_assert(buflen % sizeof(long) == 0)) { |
| errno = EINVAL; |
| return -1; |
| } |
| #endif |
| |
| /* |
| * On NetBSD before 4.0 KERN_ARND was an alias for KERN_URND, and only |
| * filled in an int, leaving the rest uninitialized. Since NetBSD 4.0 |
| * it returns a variable number of bytes with the current version supporting |
| * up to 256 bytes. |
| * Just return an error on older NetBSD versions. |
| */ |
| #if defined(__NetBSD__) && __NetBSD_Version__ < 400000000 |
| errno = ENOSYS; |
| return -1; |
| #endif |
| |
| mib[0] = CTL_KERN; |
| mib[1] = KERN_ARND; |
| |
| do { |
| len = buflen > 256 ? 256 : buflen; |
| if (sysctl(mib, 2, buf, &len, NULL, 0) == -1) |
| return done > 0 ? done : -1; |
| done += len; |
| buf += len; |
| buflen -= len; |
| } while (buflen > 0); |
| |
| return done; |
| } |
| # endif |
| |
| # if defined(OPENSSL_RAND_SEED_GETRANDOM) |
| |
| # if defined(__linux) && !defined(__NR_getrandom) |
| # if defined(__arm__) |
| # define __NR_getrandom (__NR_SYSCALL_BASE+384) |
| # elif defined(__i386__) |
| # define __NR_getrandom 355 |
| # elif defined(__x86_64__) |
| # if defined(__ILP32__) |
| # define __NR_getrandom (__X32_SYSCALL_BIT + 318) |
| # else |
| # define __NR_getrandom 318 |
| # endif |
| # elif defined(__xtensa__) |
| # define __NR_getrandom 338 |
| # elif defined(__s390__) || defined(__s390x__) |
| # define __NR_getrandom 349 |
| # elif defined(__bfin__) |
| # define __NR_getrandom 389 |
| # elif defined(__powerpc__) |
| # define __NR_getrandom 359 |
| # elif defined(__mips__) || defined(__mips64) |
| # if _MIPS_SIM == _MIPS_SIM_ABI32 |
| # define __NR_getrandom (__NR_Linux + 353) |
| # elif _MIPS_SIM == _MIPS_SIM_ABI64 |
| # define __NR_getrandom (__NR_Linux + 313) |
| # elif _MIPS_SIM == _MIPS_SIM_NABI32 |
| # define __NR_getrandom (__NR_Linux + 317) |
| # endif |
| # elif defined(__hppa__) |
| # define __NR_getrandom (__NR_Linux + 339) |
| # elif defined(__sparc__) |
| # define __NR_getrandom 347 |
| # elif defined(__ia64__) |
| # define __NR_getrandom 1339 |
| # elif defined(__alpha__) |
| # define __NR_getrandom 511 |
| # elif defined(__sh__) |
| # if defined(__SH5__) |
| # define __NR_getrandom 373 |
| # else |
| # define __NR_getrandom 384 |
| # endif |
| # elif defined(__avr32__) |
| # define __NR_getrandom 317 |
| # elif defined(__microblaze__) |
| # define __NR_getrandom 385 |
| # elif defined(__m68k__) |
| # define __NR_getrandom 352 |
| # elif defined(__cris__) |
| # define __NR_getrandom 356 |
| # elif defined(__aarch64__) |
| # define __NR_getrandom 278 |
| # else /* generic */ |
| # define __NR_getrandom 278 |
| # endif |
| # endif |
| |
| /* |
| * syscall_random(): Try to get random data using a system call |
| * returns the number of bytes returned in buf, or < 0 on error. |
| */ |
| static ssize_t syscall_random(void *buf, size_t buflen) |
| { |
| /* |
| * Note: 'buflen' equals the size of the buffer which is used by the |
| * get_entropy() callback of the RAND_DRBG. It is roughly bounded by |
| * |
| * 2 * RAND_POOL_FACTOR * (RAND_DRBG_STRENGTH / 8) = 2^14 |
| * |
| * which is way below the OSSL_SSIZE_MAX limit. Therefore sign conversion |
| * between size_t and ssize_t is safe even without a range check. |
| */ |
| |
| /* |
| * Do runtime detection to find getentropy(). |
| * |
| * Known OSs that should support this: |
| * - Darwin since 16 (OSX 10.12, IOS 10.0). |
| * - Solaris since 11.3 |
| * - OpenBSD since 5.6 |
| * - Linux since 3.17 with glibc 2.25 |
| * - FreeBSD since 12.0 (1200061) |
| */ |
| # if defined(__GNUC__) && __GNUC__>=2 && defined(__ELF__) && !defined(__hpux) |
| extern int getentropy(void *buffer, size_t length) __attribute__((weak)); |
| |
| if (getentropy != NULL) |
| return getentropy(buf, buflen) == 0 ? (ssize_t)buflen : -1; |
| # elif !defined(FIPS_MODULE) |
| union { |
| void *p; |
| int (*f)(void *buffer, size_t length); |
| } p_getentropy; |
| |
| /* |
| * We could cache the result of the lookup, but we normally don't |
| * call this function often. |
| */ |
| ERR_set_mark(); |
| p_getentropy.p = DSO_global_lookup("getentropy"); |
| ERR_pop_to_mark(); |
| if (p_getentropy.p != NULL) |
| return p_getentropy.f(buf, buflen) == 0 ? (ssize_t)buflen : -1; |
| # endif |
| |
| /* Linux supports this since version 3.17 */ |
| # if defined(__linux) && defined(__NR_getrandom) |
| return syscall(__NR_getrandom, buf, buflen, 0); |
| # elif (defined(__FreeBSD__) || defined(__NetBSD__)) && defined(KERN_ARND) |
| return sysctl_random(buf, buflen); |
| # else |
| errno = ENOSYS; |
| return -1; |
| # endif |
| } |
| # endif /* defined(OPENSSL_RAND_SEED_GETRANDOM) */ |
| |
| # if defined(OPENSSL_RAND_SEED_DEVRANDOM) |
| static const char *random_device_paths[] = { DEVRANDOM }; |
| static struct random_device { |
| int fd; |
| dev_t dev; |
| ino_t ino; |
| mode_t mode; |
| dev_t rdev; |
| } random_devices[OSSL_NELEM(random_device_paths)]; |
| static int keep_random_devices_open = 1; |
| |
| # if defined(__linux) && defined(DEVRANDOM_WAIT) \ |
| && defined(OPENSSL_RAND_SEED_GETRANDOM) |
| static void *shm_addr; |
| |
| # if !defined(FIPS_MODULE) |
| static void cleanup_shm(void) |
| { |
| shmdt(shm_addr); |
| } |
| # endif |
| |
| /* |
| * Ensure that the system randomness source has been adequately seeded. |
| * This is done by having the first start of libcrypto, wait until the device |
| * /dev/random becomes able to supply a byte of entropy. Subsequent starts |
| * of the library and later reseedings do not need to do this. |
| */ |
| static int wait_random_seeded(void) |
| { |
| static int seeded = OPENSSL_RAND_SEED_DEVRANDOM_SHM_ID < 0; |
| static const int kernel_version[] = { DEVRANDOM_SAFE_KERNEL }; |
| int kernel[2]; |
| int shm_id, fd, r; |
| char c, *p; |
| struct utsname un; |
| fd_set fds; |
| |
| if (!seeded) { |
| /* See if anything has created the global seeded indication */ |
| if ((shm_id = shmget(OPENSSL_RAND_SEED_DEVRANDOM_SHM_ID, 1, 0)) == -1) { |
| /* |
| * Check the kernel's version and fail if it is too recent. |
| * |
| * Linux kernels from 4.8 onwards do not guarantee that |
| * /dev/urandom is properly seeded when /dev/random becomes |
| * readable. However, such kernels support the getentropy(2) |
| * system call and this should always succeed which renders |
| * this alternative but essentially identical source moot. |
| */ |
| if (uname(&un) == 0) { |
| kernel[0] = atoi(un.release); |
| p = strchr(un.release, '.'); |
| kernel[1] = p == NULL ? 0 : atoi(p + 1); |
| if (kernel[0] > kernel_version[0] |
| || (kernel[0] == kernel_version[0] |
| && kernel[1] >= kernel_version[1])) { |
| return 0; |
| } |
| } |
| /* Open /dev/random and wait for it to be readable */ |
| if ((fd = open(DEVRANDOM_WAIT, O_RDONLY)) != -1) { |
| if (DEVRANDM_WAIT_USE_SELECT && fd < FD_SETSIZE) { |
| FD_ZERO(&fds); |
| FD_SET(fd, &fds); |
| while ((r = select(fd + 1, &fds, NULL, NULL, NULL)) < 0 |
| && errno == EINTR); |
| } else { |
| while ((r = read(fd, &c, 1)) < 0 && errno == EINTR); |
| } |
| close(fd); |
| if (r == 1) { |
| seeded = 1; |
| /* Create the shared memory indicator */ |
| 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); |
| # ifndef FIPS_MODULE |
| /* TODO 3.0: The FIPS provider doesn't have OPENSSL_atexit */ |
| if (shm_addr != (void *)-1) |
| OPENSSL_atexit(&cleanup_shm); |
| # endif |
| } |
| } |
| 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(OPENSSL_SYS_VXWORKS)) \ |
| || defined(__DJGPP__) |
| int rand_pool_add_nonce_data(RAND_POOL *pool) |
| { |
| struct { |
| pid_t pid; |
| CRYPTO_THREAD_ID tid; |
| uint64_t time; |
| } data; |
| |
| /* Erase the entire structure including any padding */ |
| memset(&data, 0, sizeof(data)); |
| |
| /* |
| * 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; |
| |
| /* Erase the entire structure including any padding */ |
| memset(&data, 0, sizeof(data)); |
| |
| /* |
| * 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__) */ |
