X-Git-Url: https://git.openssl.org/gitweb/?p=openssl.git;a=blobdiff_plain;f=crypto%2Frand%2Frand_lib.c;h=440c19c2872947e847cf0b2a1e123664c4d310ac;hp=143dfb0f1934e29cb03ef124f5612c4070ca66be;hb=a83dc59afa2e;hpb=2a70d65b99e1f2376be705d18bca88703b7e774a diff --git a/crypto/rand/rand_lib.c b/crypto/rand/rand_lib.c index 143dfb0f19..440c19c287 100644 --- a/crypto/rand/rand_lib.c +++ b/crypto/rand/rand_lib.c @@ -15,49 +15,8 @@ #include #include "internal/thread_once.h" #include "rand_lcl.h" -#ifdef OPENSSL_SYS_UNIX -# include -# include -# include -#endif #include "e_os.h" -/* 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 - #ifndef OPENSSL_NO_ENGINE /* non-NULL if default_RAND_meth is ENGINE-provided */ static ENGINE *funct_ref; @@ -69,6 +28,11 @@ static CRYPTO_ONCE rand_init = CRYPTO_ONCE_STATIC_INIT; int rand_fork_count; +static CRYPTO_RWLOCK *rand_nonce_lock; +static int rand_nonce_count; + +static int rand_cleaning_up = 0; + #ifdef OPENSSL_RAND_SEED_RDTSC /* * IMPORTANT NOTE: It is not currently possible to use this code @@ -125,31 +89,25 @@ size_t rand_acquire_entropy_from_cpu(RAND_POOL *pool) size_t bytes_needed; unsigned char *buffer; - bytes_needed = rand_pool_bytes_needed(pool, 8 /*entropy_per_byte*/); + bytes_needed = rand_pool_bytes_needed(pool, 1 /*entropy_factor*/); if (bytes_needed > 0) { buffer = rand_pool_add_begin(pool, bytes_needed); if (buffer != NULL) { - - /* If RDSEED is available, use that. */ + /* Whichever comes first, use RDSEED, RDRAND or nothing */ if ((OPENSSL_ia32cap_P[2] & (1 << 18)) != 0) { if (OPENSSL_ia32_rdseed_bytes(buffer, bytes_needed) - == bytes_needed) - return rand_pool_add_end(pool, - bytes_needed, - 8 * bytes_needed); - } - - /* Second choice is RDRAND. */ - if ((OPENSSL_ia32cap_P[1] & (1 << (62 - 32))) != 0) { + == bytes_needed) { + rand_pool_add_end(pool, bytes_needed, 8 * bytes_needed); + } + } else if ((OPENSSL_ia32cap_P[1] & (1 << (62 - 32))) != 0) { if (OPENSSL_ia32_rdrand_bytes(buffer, bytes_needed) - == bytes_needed) - return rand_pool_add_end(pool, - bytes_needed, - 8 * bytes_needed); + == bytes_needed) { + rand_pool_add_end(pool, bytes_needed, 8 * bytes_needed); + } + } else { + rand_pool_add_end(pool, 0, 0); } - - return rand_pool_add_end(pool, 0, 0); } } @@ -188,21 +146,17 @@ size_t rand_drbg_get_entropy(RAND_DRBG *drbg, return 0; } - pool = rand_pool_new(entropy, min_len, max_len); - if (pool == NULL) - return 0; - - if (drbg->pool) { - rand_pool_add(pool, - rand_pool_buffer(drbg->pool), - rand_pool_length(drbg->pool), - rand_pool_entropy(drbg->pool)); - rand_pool_free(drbg->pool); - drbg->pool = NULL; + if (drbg->pool != NULL) { + pool = drbg->pool; + pool->entropy_requested = entropy; + } else { + pool = rand_pool_new(entropy, min_len, max_len); + if (pool == NULL) + return 0; } if (drbg->parent) { - size_t bytes_needed = rand_pool_bytes_needed(pool, 8); + size_t bytes_needed = rand_pool_bytes_needed(pool, 1 /*entropy_factor*/); unsigned char *buffer = rand_pool_add_begin(pool, bytes_needed); if (buffer != NULL) { @@ -218,11 +172,14 @@ size_t rand_drbg_get_entropy(RAND_DRBG *drbg, if (RAND_DRBG_generate(drbg->parent, buffer, bytes_needed, prediction_resistance, - (unsigned char *)drbg, sizeof(*drbg)) != 0) + NULL, 0) != 0) bytes = bytes_needed; + drbg->reseed_next_counter + = tsan_load(&drbg->parent->reseed_prop_counter); rand_drbg_unlock(drbg->parent); - entropy_available = rand_pool_add_end(pool, bytes, 8 * bytes); + rand_pool_add_end(pool, bytes, 8 * bytes); + entropy_available = rand_pool_entropy_available(pool); } } else { @@ -234,7 +191,7 @@ size_t rand_drbg_get_entropy(RAND_DRBG *drbg, */ RANDerr(RAND_F_RAND_DRBG_GET_ENTROPY, RAND_R_PREDICTION_RESISTANCE_NOT_SUPPORTED); - return 0; + goto err; } /* Get entropy by polling system entropy sources. */ @@ -246,77 +203,75 @@ size_t rand_drbg_get_entropy(RAND_DRBG *drbg, *pout = rand_pool_detach(pool); } + err: + /* we need to reset drbg->pool in the error case */ + if (ret == 0 && drbg->pool != NULL) + drbg->pool = NULL; + rand_pool_free(pool); return ret; } /* - * Find a suitable source of time. Start with the highest resolution source - * and work down to the slower ones. This is added as additional data and - * isn't counted as randomness, so any result is acceptable. + * Implements the cleanup_entropy() callback (see RAND_DRBG_set_callbacks()) * - * Returns 0 when we weren't able to find any time source */ -static uint64_t get_timer_bits(void) +void rand_drbg_cleanup_entropy(RAND_DRBG *drbg, + unsigned char *out, size_t outlen) { - uint64_t res = OPENSSL_rdtsc(); + if (drbg->pool == NULL) + OPENSSL_secure_clear_free(out, outlen); + else + drbg->pool = NULL; +} - if (res != 0) - return res; -#if defined(_WIN32) - { - LARGE_INTEGER t; - FILETIME ft; - if (QueryPerformanceCounter(&t) != 0) - return t.QuadPart; - GetSystemTimeAsFileTime(&ft); - return TWO32TO64(ft.dwHighDateTime, ft.dwLowDateTime); - } -#elif 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); - } -#else +/* + * Implements the get_nonce() callback (see RAND_DRBG_set_callbacks()) + * + */ +size_t rand_drbg_get_nonce(RAND_DRBG *drbg, + unsigned char **pout, + int entropy, size_t min_len, size_t max_len) +{ + size_t ret = 0; + RAND_POOL *pool; -# if defined(OSSL_POSIX_TIMER_OKAY) - { - struct timespec ts; - clockid_t cid; - -# ifdef CLOCK_BOOTTIME - cid = CLOCK_BOOTTIME; -# elif defined(_POSIX_MONOTONIC_CLOCK) - cid = CLOCK_MONOTONIC; -# else - cid = CLOCK_REALTIME; -# endif - - if (clock_gettime(cid, &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 - { - time_t t = time(NULL); - if (t == (time_t)-1) - return 0; - return t; - } -#endif + struct { + void * instance; + int count; + } data = { 0 }; + + pool = rand_pool_new(0, min_len, max_len); + if (pool == NULL) + return 0; + + if (rand_pool_add_nonce_data(pool) == 0) + goto err; + + data.instance = drbg; + CRYPTO_atomic_add(&rand_nonce_count, 1, &data.count, rand_nonce_lock); + + if (rand_pool_add(pool, (unsigned char *)&data, sizeof(data), 0) == 0) + goto err; + + ret = rand_pool_length(pool); + *pout = rand_pool_detach(pool); + + err: + rand_pool_free(pool); + + return ret; +} + +/* + * Implements the cleanup_nonce() callback (see RAND_DRBG_set_callbacks()) + * + */ +void rand_drbg_cleanup_nonce(RAND_DRBG *drbg, + unsigned char *out, size_t outlen) +{ + OPENSSL_secure_clear_free(out, outlen); } /* @@ -331,86 +286,96 @@ static uint64_t get_timer_bits(void) */ size_t rand_drbg_get_additional_data(unsigned char **pout, size_t max_len) { + size_t ret = 0; RAND_POOL *pool; - CRYPTO_THREAD_ID thread_id; - size_t len; -#ifdef OPENSSL_SYS_UNIX - pid_t pid; -#elif defined(OPENSSL_SYS_WIN32) - DWORD pid; -#endif - uint64_t tbits; pool = rand_pool_new(0, 0, max_len); if (pool == NULL) return 0; -#ifdef OPENSSL_SYS_UNIX - pid = getpid(); - rand_pool_add(pool, (unsigned char *)&pid, sizeof(pid), 0); -#elif defined(OPENSSL_SYS_WIN32) - pid = GetCurrentProcessId(); - rand_pool_add(pool, (unsigned char *)&pid, sizeof(pid), 0); -#endif - - thread_id = CRYPTO_THREAD_get_current_id(); - if (thread_id != 0) - rand_pool_add(pool, (unsigned char *)&thread_id, sizeof(thread_id), 0); - - tbits = get_timer_bits(); - if (tbits != 0) - rand_pool_add(pool, (unsigned char *)&tbits, sizeof(tbits), 0); + if (rand_pool_add_additional_data(pool) == 0) + goto err; - /* TODO: Use RDSEED? */ + ret = rand_pool_length(pool); + *pout = rand_pool_detach(pool); - len = rand_pool_length(pool); - if (len != 0) - *pout = rand_pool_detach(pool); + err: rand_pool_free(pool); - return len; + return ret; } -/* - * Implements the cleanup_entropy() callback (see RAND_DRBG_set_callbacks()) - * - */ -void rand_drbg_cleanup_entropy(RAND_DRBG *drbg, - unsigned char *out, size_t outlen) +void rand_drbg_cleanup_additional_data(unsigned char *out, size_t outlen) { OPENSSL_secure_clear_free(out, outlen); } -void rand_fork() +void rand_fork(void) { rand_fork_count++; } DEFINE_RUN_ONCE_STATIC(do_rand_init) { - int ret = 1; - #ifndef OPENSSL_NO_ENGINE rand_engine_lock = CRYPTO_THREAD_lock_new(); - ret &= rand_engine_lock != NULL; + if (rand_engine_lock == NULL) + return 0; #endif + rand_meth_lock = CRYPTO_THREAD_lock_new(); - ret &= rand_meth_lock != NULL; + if (rand_meth_lock == NULL) + goto err1; - return ret; + rand_nonce_lock = CRYPTO_THREAD_lock_new(); + if (rand_nonce_lock == NULL) + goto err2; + + if (!rand_cleaning_up && !rand_pool_init()) + goto err3; + + return 1; + +err3: + rand_pool_cleanup(); +err2: + CRYPTO_THREAD_lock_free(rand_meth_lock); + rand_meth_lock = NULL; +err1: +#ifndef OPENSSL_NO_ENGINE + CRYPTO_THREAD_lock_free(rand_engine_lock); + rand_engine_lock = NULL; +#endif + return 0; } void rand_cleanup_int(void) { const RAND_METHOD *meth = default_RAND_meth; + rand_cleaning_up = 1; + if (meth != NULL && meth->cleanup != NULL) meth->cleanup(); RAND_set_rand_method(NULL); + rand_pool_cleanup(); #ifndef OPENSSL_NO_ENGINE CRYPTO_THREAD_lock_free(rand_engine_lock); + rand_engine_lock = NULL; #endif CRYPTO_THREAD_lock_free(rand_meth_lock); + rand_meth_lock = NULL; + CRYPTO_THREAD_lock_free(rand_nonce_lock); + rand_nonce_lock = NULL; +} + +/* + * RAND_close_seed_files() ensures that any seed file decriptors are + * closed after use. + */ +void RAND_keep_random_devices_open(int keep) +{ + rand_pool_keep_random_devices_open(keep); } /* @@ -445,7 +410,7 @@ int RAND_poll(void) /* fill random pool and seed the current legacy RNG */ pool = rand_pool_new(RAND_DRBG_STRENGTH, RAND_DRBG_STRENGTH / 8, - DRBG_MINMAX_FACTOR * (RAND_DRBG_STRENGTH / 8)); + RAND_POOL_MAX_LENGTH); if (pool == NULL) return 0; @@ -470,17 +435,18 @@ err: * Allocate memory and initialize a new random pool */ -RAND_POOL *rand_pool_new(int entropy, size_t min_len, size_t max_len) +RAND_POOL *rand_pool_new(int entropy_requested, size_t min_len, size_t max_len) { RAND_POOL *pool = OPENSSL_zalloc(sizeof(*pool)); if (pool == NULL) { RANDerr(RAND_F_RAND_POOL_NEW, ERR_R_MALLOC_FAILURE); - goto err; + return NULL; } pool->min_len = min_len; - pool->max_len = max_len; + pool->max_len = (max_len > RAND_POOL_MAX_LENGTH) ? + RAND_POOL_MAX_LENGTH : max_len; pool->buffer = OPENSSL_secure_zalloc(pool->max_len); if (pool->buffer == NULL) { @@ -488,7 +454,7 @@ RAND_POOL *rand_pool_new(int entropy, size_t min_len, size_t max_len) goto err; } - pool->requested_entropy = entropy; + pool->entropy_requested = entropy_requested; return pool; @@ -497,6 +463,38 @@ err: return NULL; } +/* + * Attach new random pool to the given buffer + * + * This function is intended to be used only for feeding random data + * provided by RAND_add() and RAND_seed() into the DRBG. + */ +RAND_POOL *rand_pool_attach(const unsigned char *buffer, size_t len, + size_t entropy) +{ + RAND_POOL *pool = OPENSSL_zalloc(sizeof(*pool)); + + if (pool == NULL) { + RANDerr(RAND_F_RAND_POOL_ATTACH, ERR_R_MALLOC_FAILURE); + return NULL; + } + + /* + * The const needs to be cast away, but attached buffers will not be + * modified (in contrary to allocated buffers which are zeroed and + * freed in the end). + */ + pool->buffer = (unsigned char *) buffer; + pool->len = len; + + pool->attached = 1; + + pool->min_len = pool->max_len = pool->len; + pool->entropy = entropy; + + return pool; +} + /* * Free |pool|, securely erasing its buffer. */ @@ -505,7 +503,14 @@ void rand_pool_free(RAND_POOL *pool) if (pool == NULL) return; - OPENSSL_secure_clear_free(pool->buffer, pool->max_len); + /* + * Although it would be advisable from a cryptographical viewpoint, + * we are not allowed to clear attached buffers, since they are passed + * to rand_pool_attach() as `const unsigned char*`. + * (see corresponding comment in rand_pool_attach()). + */ + if (!pool->attached) + OPENSSL_secure_clear_free(pool->buffer, pool->max_len); OPENSSL_free(pool); } @@ -547,11 +552,11 @@ unsigned char *rand_pool_detach(RAND_POOL *pool) /* - * If every byte of the input contains |entropy_per_bytes| bits of entropy, - * how many bytes does one need to obtain at least |bits| bits of entropy? + * If |entropy_factor| bits contain 1 bit of entropy, how many bytes does one + * need to obtain at least |bits| bits of entropy? */ -#define ENTROPY_TO_BYTES(bits, entropy_per_bytes) \ - (((bits) + ((entropy_per_bytes) - 1))/(entropy_per_bytes)) +#define ENTROPY_TO_BYTES(bits, entropy_factor) \ + (((bits) * (entropy_factor) + 7) / 8) /* @@ -564,7 +569,7 @@ unsigned char *rand_pool_detach(RAND_POOL *pool) */ size_t rand_pool_entropy_available(RAND_POOL *pool) { - if (pool->entropy < pool->requested_entropy) + if (pool->entropy < pool->entropy_requested) return 0; if (pool->len < pool->min_len) @@ -580,29 +585,29 @@ size_t rand_pool_entropy_available(RAND_POOL *pool) size_t rand_pool_entropy_needed(RAND_POOL *pool) { - if (pool->entropy < pool->requested_entropy) - return pool->requested_entropy - pool->entropy; + if (pool->entropy < pool->entropy_requested) + return pool->entropy_requested - pool->entropy; return 0; } /* * Returns the number of bytes needed to fill the pool, assuming - * the input has 'entropy_per_byte' entropy bits per byte. + * the input has 1 / |entropy_factor| entropy bits per data bit. * In case of an error, 0 is returned. */ -size_t rand_pool_bytes_needed(RAND_POOL *pool, unsigned int entropy_per_byte) +size_t rand_pool_bytes_needed(RAND_POOL *pool, unsigned int entropy_factor) { size_t bytes_needed; size_t entropy_needed = rand_pool_entropy_needed(pool); - if (entropy_per_byte < 1 || entropy_per_byte > 8) { + if (entropy_factor < 1) { RANDerr(RAND_F_RAND_POOL_BYTES_NEEDED, RAND_R_ARGUMENT_OUT_OF_RANGE); return 0; } - bytes_needed = ENTROPY_TO_BYTES(entropy_needed, entropy_per_byte); + bytes_needed = ENTROPY_TO_BYTES(entropy_needed, entropy_factor); if (bytes_needed > pool->max_len - pool->len) { /* not enough space left */ @@ -631,11 +636,10 @@ size_t rand_pool_bytes_remaining(RAND_POOL *pool) * random input which contains at least |entropy| bits of * randomness. * - * Return available amount of entropy after this operation. - * (see rand_pool_entropy_available(pool)) + * Returns 1 if the added amount is adequate, otherwise 0 */ -size_t rand_pool_add(RAND_POOL *pool, - const unsigned char *buffer, size_t len, size_t entropy) +int rand_pool_add(RAND_POOL *pool, + const unsigned char *buffer, size_t len, size_t entropy) { if (len > pool->max_len - pool->len) { RANDerr(RAND_F_RAND_POOL_ADD, RAND_R_ENTROPY_INPUT_TOO_LONG); @@ -648,7 +652,7 @@ size_t rand_pool_add(RAND_POOL *pool, pool->entropy += entropy; } - return rand_pool_entropy_available(pool); + return 1; } /* @@ -685,7 +689,7 @@ unsigned char *rand_pool_add_begin(RAND_POOL *pool, size_t len) * to the buffer which contain at least |entropy| bits of randomness. * It is allowed to add less bytes than originally reserved. */ -size_t rand_pool_add_end(RAND_POOL *pool, size_t len, size_t entropy) +int rand_pool_add_end(RAND_POOL *pool, size_t len, size_t entropy) { if (len > pool->max_len - pool->len) { RANDerr(RAND_F_RAND_POOL_ADD_END, RAND_R_RANDOM_POOL_OVERFLOW); @@ -697,7 +701,7 @@ size_t rand_pool_add_end(RAND_POOL *pool, size_t len, size_t entropy) pool->entropy += entropy; } - return rand_pool_entropy_available(pool); + return 1; } int RAND_set_rand_method(const RAND_METHOD *meth)