From 933033b6928e9f01b99e7f2125f840bc052c5d96 Mon Sep 17 00:00:00 2001 From: "Dr. Matthias St. Pierre" Date: Mon, 6 Nov 2017 02:29:15 +0100 Subject: [PATCH] Allocate the three shared DRBGs on the secure heap Signed-off-by: Dr. Matthias St. Pierre Reviewed-by: Paul Dale Reviewed-by: Kurt Roeckx (Merged from https://github.com/openssl/openssl/pull/4402) --- crypto/rand/drbg_lib.c | 74 ++++++++++++++++++++++++++---------------- 1 file changed, 46 insertions(+), 28 deletions(-) diff --git a/crypto/rand/drbg_lib.c b/crypto/rand/drbg_lib.c index 13dce3057c..813dba3d3d 100644 --- a/crypto/rand/drbg_lib.c +++ b/crypto/rand/drbg_lib.c @@ -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 * @@ -98,7 +98,8 @@ 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|. @@ -620,30 +621,37 @@ 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) { drbg->reseed_interval = MASTER_RESEED_INTERVAL; @@ -666,7 +674,11 @@ 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; } /* @@ -675,28 +687,34 @@ static int drbg_setup(RAND_DRBG *drbg, const char *name, RAND_DRBG *parent) */ DEFINE_RUN_ONCE_STATIC(do_rand_drbg_init) { - int ret = 1; + drbg_master = drbg_setup("drbg_master", NULL); + drbg_public = drbg_setup("drbg_public", drbg_master); + drbg_private = drbg_setup("drbg_private", drbg_master); - 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); + if (drbg_master == NULL || drbg_public == NULL || drbg_private == NULL) + return 0; - return ret; + 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 */ @@ -790,7 +808,7 @@ 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; } /* @@ -802,7 +820,7 @@ 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; } /* @@ -814,7 +832,7 @@ 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 = { -- 2.25.1