X-Git-Url: https://git.openssl.org/?p=openssl.git;a=blobdiff_plain;f=crypto%2Frand%2Fdrbg_lib.c;h=5e6bdceb1ed77c45fad3f7c6e4171c74650655aa;hp=67a79d4efeb8776080cce2d6dccd8e2f732ec70f;hb=20928ff635772182fe8696d618a19f9101a5370f;hpb=a93ba405b0327db9106f8f224112a2b64fb264e7 diff --git a/crypto/rand/drbg_lib.c b/crypto/rand/drbg_lib.c index 67a79d4efe..5e6bdceb1e 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 @@ -39,19 +39,19 @@ * DRBGs. It reseeds itself by pulling either randomness from os entropy * sources or by consuming randomnes which was added by RAND_add() */ -static RAND_DRBG drbg_master; +static RAND_DRBG *drbg_master; /* * THE PUBLIC DRBG * * Used by default for generating random bytes using RAND_bytes(). */ -static RAND_DRBG drbg_public; +static RAND_DRBG *drbg_public; /* * THE PRIVATE DRBG * * Used by default for generating private keys using RAND_priv_bytes() */ -static RAND_DRBG drbg_private; +static RAND_DRBG *drbg_private; /*+ * DRBG HIERARCHY * @@ -72,18 +72,24 @@ static RAND_DRBG drbg_private; * * AUTOMATIC RESEEDING * - * Before satisfying a generate request, a DRBG reseeds itself automatically - * if the number of generate requests since the last reseeding exceeds a - * certain threshold, the so called |reseed_interval|. This automatic - * reseeding can be disabled by setting the |reseed_interval| to 0. + * Before satisfying a generate request, a DRBG reseeds itself automatically, + * if one of the following two conditions holds: + * + * - the number of generate requests since the last reseeding exceeds a + * certain threshold, the so called |reseed_interval|. This behaviour + * can be disabled by setting the |reseed_interval| to 0. + * + * - the time elapsed since the last reseeding exceeds a certain time + * interval, the so called |reseed_time_interval|. This behaviour + * can be disabled by setting the |reseed_time_interval| to 0. * * MANUAL RESEEDING * - * For the three shared DRBGs (and only for these) there is a way to reseed - * them manually by calling RAND_seed() (or RAND_add() with a positive + * For the three shared DRBGs (and only for these) there is another way to + * reseed them manually by calling RAND_seed() (or RAND_add() with a positive * |randomness| argument). This will immediately reseed the DRBG. - * Its immediate children ( and DRBG) will detect this - * on their next generate call and reseed, pulling randomness from . + * The and DRBG will detect this on their next generate + * call and reseed, pulling randomness from . */ @@ -92,12 +98,13 @@ static const char ossl_pers_string[] = "OpenSSL NIST SP 800-90A DRBG"; static CRYPTO_ONCE rand_drbg_init = CRYPTO_ONCE_STATIC_INIT; -static int drbg_setup(RAND_DRBG *drbg, const char *name, RAND_DRBG *parent); +static RAND_DRBG *drbg_setup(const char *name, RAND_DRBG *parent); +static void drbg_cleanup(RAND_DRBG *drbg); /* * 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) { @@ -110,18 +117,18 @@ 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; } @@ -142,7 +149,7 @@ RAND_DRBG *RAND_DRBG_new(int type, unsigned int flags, RAND_DRBG *parent) } 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, @@ -165,7 +172,8 @@ void RAND_DRBG_free(RAND_DRBG *drbg) if (drbg == NULL) return; - ctr_uninstantiate(drbg); + if (drbg->meth != NULL) + drbg->meth->uninstantiate(drbg); CRYPTO_free_ex_data(CRYPTO_EX_INDEX_DRBG, drbg, &drbg->ex_data); OPENSSL_clear_free(drbg, sizeof(*drbg)); } @@ -175,6 +183,8 @@ 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) @@ -187,6 +197,14 @@ 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 @@ -214,7 +232,7 @@ 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; @@ -222,7 +240,7 @@ int RAND_DRBG_instantiate(RAND_DRBG *drbg, drbg->state = DRBG_READY; drbg->generate_counter = 0; - + drbg->reseed_time = time(NULL); if (drbg->reseed_counter > 0) { if (drbg->parent == NULL) drbg->reseed_counter++; @@ -253,19 +271,32 @@ 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) @@ -299,12 +330,12 @@ 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; drbg->generate_counter = 0; - + drbg->reseed_time = time(NULL); if (drbg->reseed_counter > 0) { if (drbg->parent == NULL) drbg->reseed_counter++; @@ -381,11 +412,8 @@ 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) { @@ -408,7 +436,7 @@ 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); @@ -475,7 +503,12 @@ int RAND_DRBG_generate(RAND_DRBG *drbg, unsigned char *out, size_t outlen, if (drbg->generate_counter >= drbg->reseed_interval) reseed_required = 1; } - + if (drbg->reseed_time_interval > 0) { + time_t now = time(NULL); + if (now < drbg->reseed_time + || now - drbg->reseed_time >= drbg->reseed_time_interval) + reseed_required = 1; + } if (drbg->reseed_counter > 0 && drbg->parent != NULL) { if (drbg->reseed_counter != drbg->parent->reseed_counter) reseed_required = 1; @@ -490,7 +523,7 @@ 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; @@ -501,6 +534,28 @@ 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 ret; + + additional_len = rand_drbg_get_additional_data(&additional, drbg->max_adinlen); + ret = RAND_DRBG_generate(drbg, out, outlen, 0, additional, additional_len); + if (additional_len != 0) + OPENSSL_secure_clear_free(additional, additional_len); + + return ret; +} + /* * Set the RAND_DRBG callbacks for obtaining entropy and nonce. * @@ -559,7 +614,7 @@ int RAND_DRBG_set_callbacks(RAND_DRBG *drbg, * * The drbg will reseed automatically whenever the number of generate * requests exceeds the given reseed interval. If the reseed interval - * is 0, then this automatic reseeding is disabled. + * is 0, then this feature is disabled. * * Returns 1 on success, 0 on failure. */ @@ -571,6 +626,24 @@ int RAND_DRBG_set_reseed_interval(RAND_DRBG *drbg, unsigned int interval) return 1; } +/* + * Set the reseed time interval. + * + * The drbg will reseed automatically whenever the time elapsed since + * the last reseeding exceeds the given reseed time interval. For safety, + * a reseeding will also occur if the clock has been reset to a smaller + * value. + * + * Returns 1 on success, 0 on failure. + */ +int RAND_DRBG_set_reseed_time_interval(RAND_DRBG *drbg, time_t interval) +{ + if (interval > MAX_RESEED_TIME_INTERVAL) + return 0; + drbg->reseed_time_interval = interval; + return 1; +} + /* * Get and set the EXDATA */ @@ -591,36 +664,45 @@ void *RAND_DRBG_get_ex_data(const RAND_DRBG *drbg, int idx) */ /* - * Initializes the given global DRBG with default settings. + * 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 int drbg_setup(RAND_DRBG *drbg, const char *name, RAND_DRBG *parent) +static RAND_DRBG *drbg_setup(const char *name, RAND_DRBG *parent) { - int ret = 1; + RAND_DRBG *drbg; - if (name == NULL || drbg->lock != NULL) { + if (name == NULL) { RANDerr(RAND_F_DRBG_SETUP, ERR_R_INTERNAL_ERROR); - return 0; + return NULL; } + drbg = OPENSSL_secure_zalloc(sizeof(RAND_DRBG)); + 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); - return 0; + goto err; } - ret &= RAND_DRBG_set(drbg, - RAND_DRBG_NID, RAND_DRBG_FLAG_CTR_USE_DF) == 1; - ret &= RAND_DRBG_set_callbacks(drbg, rand_drbg_get_entropy, - rand_drbg_cleanup_entropy, NULL, NULL) == 1; + 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) + goto err; - if (parent == NULL) + if (parent == NULL) { drbg->reseed_interval = MASTER_RESEED_INTERVAL; - else { + 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; } /* enable seed propagation */ @@ -635,7 +717,11 @@ static int drbg_setup(RAND_DRBG *drbg, const char *name, RAND_DRBG *parent) RAND_DRBG_instantiate(drbg, (const unsigned char *) ossl_pers_string, sizeof(ossl_pers_string) - 1); - return ret; + return drbg; + +err: + drbg_cleanup(drbg); + return NULL; } /* @@ -644,28 +730,41 @@ static int drbg_setup(RAND_DRBG *drbg, const char *name, RAND_DRBG *parent) */ DEFINE_RUN_ONCE_STATIC(do_rand_drbg_init) { - int ret = 1; + /* + * ensure that libcrypto is initialized, otherwise the + * DRBG locks are not cleaned up properly + */ + if (!OPENSSL_init_crypto(0, NULL)) + return 0; - ret &= drbg_setup(&drbg_master, "drbg_master", NULL); - ret &= drbg_setup(&drbg_public, "drbg_public", &drbg_master); - ret &= drbg_setup(&drbg_private, "drbg_private", &drbg_master); + drbg_master = drbg_setup("drbg_master", NULL); + drbg_public = drbg_setup("drbg_public", drbg_master); + drbg_private = drbg_setup("drbg_private", drbg_master); - return ret; + if (drbg_master == NULL || drbg_public == NULL || drbg_private == NULL) + return 0; + + return 1; } /* Cleans up the given global DRBG */ static void drbg_cleanup(RAND_DRBG *drbg) { - CRYPTO_THREAD_lock_free(drbg->lock); - RAND_DRBG_uninstantiate(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); + drbg_cleanup(drbg_private); + drbg_cleanup(drbg_public); + drbg_cleanup(drbg_master); + + drbg_private = drbg_public = drbg_master = NULL; } /* Implements the default OpenSSL RAND_bytes() method */ @@ -759,7 +858,7 @@ RAND_DRBG *RAND_DRBG_get0_master(void) if (!RUN_ONCE(&rand_drbg_init, do_rand_drbg_init)) return NULL; - return &drbg_master; + return drbg_master; } /* @@ -771,7 +870,7 @@ RAND_DRBG *RAND_DRBG_get0_public(void) if (!RUN_ONCE(&rand_drbg_init, do_rand_drbg_init)) return NULL; - return &drbg_public; + return drbg_public; } /* @@ -783,7 +882,7 @@ RAND_DRBG *RAND_DRBG_get0_private(void) if (!RUN_ONCE(&rand_drbg_init, do_rand_drbg_init)) return NULL; - return &drbg_private; + return drbg_private; } RAND_METHOD rand_meth = {