X-Git-Url: https://git.openssl.org/gitweb/?a=blobdiff_plain;f=crypto%2Frand%2Fdrbg_lib.c;h=c592a7b9d07486774a465d912e2a615d2f1fdcb0;hb=8164d91d1802e6173291dee50923cc60fcd3bf72;hp=813dba3d3d9b240c5c929e7ca41ffa9090632f59;hpb=933033b6928e9f01b99e7f2125f840bc052c5d96;p=openssl.git diff --git a/crypto/rand/drbg_lib.c b/crypto/rand/drbg_lib.c index 813dba3d3d..c592a7b9d0 100644 --- a/crypto/rand/drbg_lib.c +++ b/crypto/rand/drbg_lib.c @@ -1,5 +1,5 @@ /* - * Copyright 2011-2017 The OpenSSL Project Authors. All Rights Reserved. + * Copyright 2011-2018 The OpenSSL Project Authors. All Rights Reserved. * * Licensed under the OpenSSL license (the "License"). You may not use * this file except in compliance with the License. You can obtain a copy @@ -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 by default. It is the callers responsibility to wrap + * calls to functions like RAND_DRBG_generate() which modify the DRBGs + * internal state with calls to RAND_DRBG_lock() and RAND_DRBG_unlock(). + * The functions RAND_bytes() and RAND_priv_bytes() take the locks + * automatically, so using the RAND api is thread safe as before. + * + * All other DRBG instances don't have locking enabled by default, because + * they are intendended to be used by a single thread. If it is desired, + * locking can be enabled using RAND_DRBG_enable_locking(). However, instead + * of accessing a single DRBG instance concurrently from different threads, + * it is recommended to instantiate a separate DRBG instance per thread. */ @@ -98,13 +113,17 @@ 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|. - * Return -2 if the type is not supported, 1 on success and -1 on - * failure. + * + * Returns 1 on success, 0 on failure. */ int RAND_DRBG_set(RAND_DRBG *drbg, int nid, unsigned int flags) { @@ -117,39 +136,46 @@ int RAND_DRBG_set(RAND_DRBG *drbg, int nid, unsigned int flags) switch (nid) { default: RANDerr(RAND_F_RAND_DRBG_SET, RAND_R_UNSUPPORTED_DRBG_TYPE); - return -2; + return 0; case 0: /* Uninitialized; that's okay. */ return 1; case NID_aes_128_ctr: case NID_aes_192_ctr: case NID_aes_256_ctr: - ret = ctr_init(drbg); + ret = drbg_ctr_init(drbg); break; } - if (ret < 0) + if (ret == 0) RANDerr(RAND_F_RAND_DRBG_SET, RAND_R_ERROR_INITIALISING_DRBG); return ret; } /* - * 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) + if (RAND_DRBG_set(drbg, type, flags) == 0) goto err; if (!RAND_DRBG_set_callbacks(drbg, rand_drbg_get_entropy, @@ -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. */ @@ -172,9 +212,15 @@ void RAND_DRBG_free(RAND_DRBG *drbg) if (drbg == NULL) return; - ctr_uninstantiate(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)); } /* @@ -182,6 +228,8 @@ void RAND_DRBG_free(RAND_DRBG *drbg) * |perslen| as prediction-resistance input. * * Requires that drbg->lock is already locked for write, if non-null. + * + * Returns 1 on success, 0 on failure. */ int RAND_DRBG_instantiate(RAND_DRBG *drbg, const unsigned char *pers, size_t perslen) @@ -194,6 +242,14 @@ int RAND_DRBG_instantiate(RAND_DRBG *drbg, RAND_R_PERSONALISATION_STRING_TOO_LONG); goto end; } + + if (drbg->meth == NULL) + { + RANDerr(RAND_F_RAND_DRBG_INSTANTIATE, + RAND_R_NO_DRBG_IMPLEMENTATION_SELECTED); + goto end; + } + if (drbg->state != DRBG_UNINITIALISED) { RANDerr(RAND_F_RAND_DRBG_INSTANTIATE, drbg->state == DRBG_ERROR ? RAND_R_IN_ERROR_STATE @@ -221,7 +277,7 @@ int RAND_DRBG_instantiate(RAND_DRBG *drbg, } } - if (!ctr_instantiate(drbg, entropy, entropylen, + if (!drbg->meth->instantiate(drbg, entropy, entropylen, nonce, noncelen, pers, perslen)) { RANDerr(RAND_F_RAND_DRBG_INSTANTIATE, RAND_R_ERROR_INSTANTIATING_DRBG); goto end; @@ -260,19 +316,32 @@ end: * Uninstantiate |drbg|. Must be instantiated before it can be used. * * Requires that drbg->lock is already locked for write, if non-null. + * + * Returns 1 on success, 0 on failure. */ int RAND_DRBG_uninstantiate(RAND_DRBG *drbg) { - int ret = ctr_uninstantiate(drbg); + if (drbg->meth == NULL) + { + RANDerr(RAND_F_RAND_DRBG_UNINSTANTIATE, + RAND_R_NO_DRBG_IMPLEMENTATION_SELECTED); + return 0; + } - drbg->state = DRBG_UNINITIALISED; - return ret; + /* Clear the entire drbg->ctr struct, then reset some important + * members of the drbg->ctr struct (e.g. keysize, df_ks) to their + * initial values. + */ + drbg->meth->uninstantiate(drbg); + return RAND_DRBG_set(drbg, drbg->nid, drbg->flags); } /* * Reseed |drbg|, mixing in the specified data * * Requires that drbg->lock is already locked for write, if non-null. + * + * Returns 1 on success, 0 on failure. */ int RAND_DRBG_reseed(RAND_DRBG *drbg, const unsigned char *adin, size_t adinlen) @@ -306,7 +375,7 @@ int RAND_DRBG_reseed(RAND_DRBG *drbg, goto end; } - if (!ctr_reseed(drbg, entropy, entropylen, adin, adinlen)) + if (!drbg->meth->reseed(drbg, entropy, entropylen, adin, adinlen)) goto end; drbg->state = DRBG_READY; @@ -388,11 +457,8 @@ int rand_drbg_restart(RAND_DRBG *drbg, } /* repair error state */ - if (drbg->state == DRBG_ERROR) { + if (drbg->state == DRBG_ERROR) RAND_DRBG_uninstantiate(drbg); - /* The drbg->ctr member needs to be reinitialized before reinstantiation */ - RAND_DRBG_set(drbg, drbg->nid, drbg->flags); - } /* repair uninitialized state */ if (drbg->state == DRBG_UNINITIALISED) { @@ -415,7 +481,7 @@ int rand_drbg_restart(RAND_DRBG *drbg, * entropy from the trusted entropy source using get_entropy(). * This is not a reseeding in the strict sense of NIST SP 800-90A. */ - ctr_reseed(drbg, adin, adinlen, NULL, 0); + drbg->meth->reseed(drbg, adin, adinlen, NULL, 0); } else if (reseeded == 0) { /* do a full reseeding if it has not been done yet above */ RAND_DRBG_reseed(drbg, NULL, 0); @@ -502,7 +568,7 @@ int RAND_DRBG_generate(RAND_DRBG *drbg, unsigned char *out, size_t outlen, adinlen = 0; } - if (!ctr_generate(drbg, out, outlen, adin, adinlen)) { + if (!drbg->meth->generate(drbg, out, outlen, adin, adinlen)) { drbg->state = DRBG_ERROR; RANDerr(RAND_F_RAND_DRBG_GENERATE, RAND_R_GENERATE_ERROR); return 0; @@ -513,6 +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. * @@ -601,6 +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 */ @@ -623,41 +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; } @@ -677,7 +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; } @@ -687,9 +833,16 @@ err: */ DEFINE_RUN_ONCE_STATIC(do_rand_drbg_init) { - drbg_master = drbg_setup("drbg_master", NULL); - drbg_public = drbg_setup("drbg_public", drbg_master); - drbg_private = drbg_setup("drbg_private", drbg_master); + /* + * ensure that libcrypto is initialized, otherwise the + * DRBG locks are not cleaned up properly + */ + if (!OPENSSL_init_crypto(0, NULL)) + return 0; + + 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; @@ -697,22 +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; } @@ -720,29 +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; + RAND_DRBG_lock(drbg); + ret = RAND_DRBG_bytes(drbg, out, count); + RAND_DRBG_unlock(drbg); - 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; - -err: - CRYPTO_THREAD_unlock(drbg->lock); return ret; } @@ -768,11 +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; } @@ -792,9 +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; }