X-Git-Url: https://git.openssl.org/gitweb/?p=openssl.git;a=blobdiff_plain;f=crypto%2Frand%2Fdrbg_lib.c;h=c43f571d643ed0e88ce5c945db7cd967ade40150;hp=5d3d0f2fd718fe92ae6e7ae9a8f8afd43ae1ea27;hb=812b15370613da4768d91b9e566fdf5a30c06805;hpb=39571fcabf688a6efc4a567f6a8e5d4297b064cb diff --git a/crypto/rand/drbg_lib.c b/crypto/rand/drbg_lib.c index 5d3d0f2fd7..c43f571d64 100644 --- a/crypto/rand/drbg_lib.c +++ b/crypto/rand/drbg_lib.c @@ -90,6 +90,21 @@ static RAND_DRBG *drbg_private; * |randomness| argument). This will immediately reseed the DRBG. * The and DRBG will detect this on their next generate * call and reseed, pulling randomness from . + * + * LOCKING + * + * The three shared DRBGs are intended to be used concurrently, so they + * support locking. The RAND methods take the locks automatically, so using + * the RAND api (in particular RAND_bytes() and RAND_priv_bytes()) is + * thread-safe. Note however that accessing the shared DRBGs directly via + * the RAND_DRBG interface is *not* thread-safe. + * + * All other DRBG instances don't support locking, because they are + * intendended to be used by a single thread. Instead of accessing a single + * DRBG instance concurrently from different threads, it is recommended to + * instantiate a separate DRBG instance per thread. Using the same shared + * DRBG (preferrably the public DRBG) as parent of DRBG instances on + * different threads is safe. */ @@ -98,8 +113,12 @@ static const char ossl_pers_string[] = "OpenSSL NIST SP 800-90A DRBG"; static CRYPTO_ONCE rand_drbg_init = CRYPTO_ONCE_STATIC_INIT; -static RAND_DRBG *drbg_setup(const char *name, RAND_DRBG *parent); -static void drbg_cleanup(RAND_DRBG *drbg); +static RAND_DRBG *drbg_setup(RAND_DRBG *parent); + +static RAND_DRBG *rand_drbg_new(int secure, + int type, + unsigned int flags, + RAND_DRBG *parent); /* * Set/initialize |drbg| to be of type |nid|, with optional |flags|. @@ -134,19 +153,26 @@ int RAND_DRBG_set(RAND_DRBG *drbg, int nid, unsigned int flags) } /* - * Allocate memory and initialize a new DRBG. The |parent|, if not - * NULL, will be used to auto-seed this RAND_DRBG as needed. + * Allocate memory and initialize a new DRBG. The DRBG is allocated on + * the secure heap if |secure| is nonzero and the secure heap is enabled. + * The |parent|, if not NULL, will be used as random source for reseeding. * * Returns a pointer to the new DRBG instance on success, NULL on failure. */ -RAND_DRBG *RAND_DRBG_new(int type, unsigned int flags, RAND_DRBG *parent) +static RAND_DRBG *rand_drbg_new(int secure, + int type, + unsigned int flags, + RAND_DRBG *parent) { - RAND_DRBG *drbg = OPENSSL_zalloc(sizeof(*drbg)); + RAND_DRBG *drbg = secure ? + OPENSSL_secure_zalloc(sizeof(*drbg)) : OPENSSL_zalloc(sizeof(*drbg)); if (drbg == NULL) { RANDerr(RAND_F_RAND_DRBG_NEW, ERR_R_MALLOC_FAILURE); goto err; } + + drbg->secure = secure && CRYPTO_secure_allocated(drbg); drbg->fork_count = rand_fork_count; drbg->parent = parent; if (RAND_DRBG_set(drbg, type, flags) == 0) @@ -160,10 +186,24 @@ RAND_DRBG *RAND_DRBG_new(int type, unsigned int flags, RAND_DRBG *parent) return drbg; err: - OPENSSL_free(drbg); + if (drbg->secure) + OPENSSL_secure_free(drbg); + else + OPENSSL_free(drbg); + return NULL; } +RAND_DRBG *RAND_DRBG_new(int type, unsigned int flags, RAND_DRBG *parent) +{ + return rand_drbg_new(0, type, flags, parent); +} + +RAND_DRBG *RAND_DRBG_secure_new(int type, unsigned int flags, RAND_DRBG *parent) +{ + return rand_drbg_new(1, type, flags, parent); +} + /* * Uninstantiate |drbg| and free all memory. */ @@ -174,8 +214,13 @@ void RAND_DRBG_free(RAND_DRBG *drbg) if (drbg->meth != NULL) drbg->meth->uninstantiate(drbg); + CRYPTO_THREAD_lock_free(drbg->lock); CRYPTO_free_ex_data(CRYPTO_EX_INDEX_DRBG, drbg, &drbg->ex_data); - OPENSSL_clear_free(drbg, sizeof(*drbg)); + + if (drbg->secure) + OPENSSL_secure_clear_free(drbg, sizeof(*drbg)); + else + OPENSSL_clear_free(drbg, sizeof(*drbg)); } /* @@ -534,6 +579,40 @@ int RAND_DRBG_generate(RAND_DRBG *drbg, unsigned char *out, size_t outlen, return 1; } +/* + * Generates |outlen| random bytes and stores them in |out|. It will + * using the given |drbg| to generate the bytes. + * + * Requires that drbg->lock is already locked for write, if non-null. + * + * Returns 1 on success 0 on failure. + */ +int RAND_DRBG_bytes(RAND_DRBG *drbg, unsigned char *out, size_t outlen) +{ + unsigned char *additional = NULL; + size_t additional_len; + size_t chunk; + size_t ret; + + additional_len = rand_drbg_get_additional_data(&additional, drbg->max_adinlen); + + for ( ; outlen > 0; outlen -= chunk, out += chunk) { + chunk = outlen; + if (chunk > drbg->max_request) + chunk = drbg->max_request; + ret = RAND_DRBG_generate(drbg, out, chunk, 0, additional, additional_len); + if (!ret) + goto err; + } + ret = 1; + +err: + if (additional_len != 0) + OPENSSL_secure_clear_free(additional, additional_len); + + return ret; +} + /* * Set the RAND_DRBG callbacks for obtaining entropy and nonce. * @@ -622,6 +701,69 @@ int RAND_DRBG_set_reseed_time_interval(RAND_DRBG *drbg, time_t interval) return 1; } + +/* + * Locks the given drbg. Locking a drbg which does not have locking + * enabled is considered a successful no-op. + * + * Returns 1 on success, 0 on failure. + */ +int rand_drbg_lock(RAND_DRBG *drbg) +{ + if (drbg->lock != NULL) + return CRYPTO_THREAD_write_lock(drbg->lock); + + return 1; +} + +/* + * Unlocks the given drbg. Unlocking a drbg which does not have locking + * enabled is considered a successful no-op. + * + * Returns 1 on success, 0 on failure. + */ +int rand_drbg_unlock(RAND_DRBG *drbg) +{ + if (drbg->lock != NULL) + return CRYPTO_THREAD_unlock(drbg->lock); + + return 1; +} + +/* + * Enables locking for the given drbg + * + * Locking can only be enabled if the random generator + * is in the uninitialized state. + * + * Returns 1 on success, 0 on failure. + */ +int rand_drbg_enable_locking(RAND_DRBG *drbg) +{ + if (drbg->state != DRBG_UNINITIALISED) { + RANDerr(RAND_F_RAND_DRBG_ENABLE_LOCKING, + RAND_R_DRBG_ALREADY_INITIALIZED); + return 0; + } + + if (drbg->lock == NULL) { + if (drbg->parent != NULL && drbg->parent->lock == NULL) { + RANDerr(RAND_F_RAND_DRBG_ENABLE_LOCKING, + RAND_R_PARENT_LOCKING_NOT_ENABLED); + return 0; + } + + drbg->lock = CRYPTO_THREAD_lock_new(); + if (drbg->lock == NULL) { + RANDerr(RAND_F_RAND_DRBG_ENABLE_LOCKING, + RAND_R_FAILED_TO_CREATE_LOCK); + return 0; + } + } + + return 1; +} + /* * Get and set the EXDATA */ @@ -644,41 +786,24 @@ void *RAND_DRBG_get_ex_data(const RAND_DRBG *drbg, int idx) /* * Allocates a new global DRBG on the secure heap (if enabled) and * initializes it with default settings. - * A global lock for the DRBG is created with the given name. * * Returns a pointer to the new DRBG instance on success, NULL on failure. */ -static RAND_DRBG *drbg_setup(const char *name, RAND_DRBG *parent) +static RAND_DRBG *drbg_setup(RAND_DRBG *parent) { RAND_DRBG *drbg; - if (name == NULL) { - RANDerr(RAND_F_DRBG_SETUP, ERR_R_INTERNAL_ERROR); - return NULL; - } - - drbg = OPENSSL_secure_zalloc(sizeof(RAND_DRBG)); + drbg = RAND_DRBG_secure_new(RAND_DRBG_NID, 0, parent); if (drbg == NULL) return NULL; - drbg->lock = CRYPTO_THREAD_glock_new(name); - if (drbg->lock == NULL) { - RANDerr(RAND_F_DRBG_SETUP, RAND_R_FAILED_TO_CREATE_LOCK); - goto err; - } - - if (RAND_DRBG_set(drbg, - RAND_DRBG_NID, RAND_DRBG_FLAG_CTR_USE_DF) != 1) - goto err; - if (RAND_DRBG_set_callbacks(drbg, rand_drbg_get_entropy, - rand_drbg_cleanup_entropy, NULL, NULL) != 1) + if (rand_drbg_enable_locking(drbg) == 0) goto err; if (parent == NULL) { drbg->reseed_interval = MASTER_RESEED_INTERVAL; drbg->reseed_time_interval = MASTER_RESEED_TIME_INTERVAL; } else { - drbg->parent = parent; drbg->reseed_interval = SLAVE_RESEED_INTERVAL; drbg->reseed_time_interval = SLAVE_RESEED_TIME_INTERVAL; } @@ -698,7 +823,7 @@ static RAND_DRBG *drbg_setup(const char *name, RAND_DRBG *parent) return drbg; err: - drbg_cleanup(drbg); + RAND_DRBG_free(drbg); return NULL; } @@ -715,9 +840,9 @@ DEFINE_RUN_ONCE_STATIC(do_rand_drbg_init) if (!OPENSSL_init_crypto(0, NULL)) return 0; - drbg_master = drbg_setup("drbg_master", NULL); - drbg_public = drbg_setup("drbg_public", drbg_master); - drbg_private = drbg_setup("drbg_private", drbg_master); + drbg_master = drbg_setup(NULL); + drbg_public = drbg_setup(drbg_master); + drbg_private = drbg_setup(drbg_master); if (drbg_master == NULL || drbg_public == NULL || drbg_private == NULL) return 0; @@ -725,22 +850,12 @@ DEFINE_RUN_ONCE_STATIC(do_rand_drbg_init) return 1; } -/* Cleans up the given global DRBG */ -static void drbg_cleanup(RAND_DRBG *drbg) -{ - if (drbg != NULL) { - RAND_DRBG_uninstantiate(drbg); - CRYPTO_THREAD_lock_free(drbg->lock); - OPENSSL_secure_clear_free(drbg, sizeof(RAND_DRBG)); - } -} - /* Clean up the global DRBGs before exit */ void rand_drbg_cleanup_int(void) { - drbg_cleanup(drbg_private); - drbg_cleanup(drbg_public); - drbg_cleanup(drbg_master); + RAND_DRBG_free(drbg_private); + RAND_DRBG_free(drbg_public); + RAND_DRBG_free(drbg_master); drbg_private = drbg_public = drbg_master = NULL; } @@ -748,29 +863,16 @@ void rand_drbg_cleanup_int(void) /* Implements the default OpenSSL RAND_bytes() method */ static int drbg_bytes(unsigned char *out, int count) { - int ret = 0; - size_t chunk; + int ret; RAND_DRBG *drbg = RAND_DRBG_get0_public(); if (drbg == NULL) return 0; - CRYPTO_THREAD_write_lock(drbg->lock); - if (drbg->state == DRBG_UNINITIALISED) - goto err; - - for ( ; count > 0; count -= chunk, out += chunk) { - chunk = count; - if (chunk > drbg->max_request) - chunk = drbg->max_request; - ret = RAND_DRBG_generate(drbg, out, chunk, 0, NULL, 0); - if (!ret) - goto err; - } - ret = 1; + rand_drbg_lock(drbg); + ret = RAND_DRBG_bytes(drbg, out, count); + rand_drbg_unlock(drbg); -err: - CRYPTO_THREAD_unlock(drbg->lock); return ret; } @@ -796,11 +898,11 @@ static int drbg_add(const void *buf, int num, double randomness) return 0; } - CRYPTO_THREAD_write_lock(drbg->lock); + rand_drbg_lock(drbg); ret = rand_drbg_restart(drbg, buf, (size_t)(unsigned int)num, (size_t)(8*randomness)); - CRYPTO_THREAD_unlock(drbg->lock); + rand_drbg_unlock(drbg); return ret; } @@ -820,9 +922,9 @@ static int drbg_status(void) if (drbg == NULL) return 0; - CRYPTO_THREAD_write_lock(drbg->lock); + rand_drbg_lock(drbg); ret = drbg->state == DRBG_READY ? 1 : 0; - CRYPTO_THREAD_unlock(drbg->lock); + rand_drbg_unlock(drbg); return ret; }