From 81aef6ba720971c09ad68f89d418c8d3d3f904f7 Mon Sep 17 00:00:00 2001 From: Pauli Date: Fri, 20 Nov 2020 08:45:34 +1000 Subject: [PATCH] rand: add a provider side seed source. This allows the operating system sources that OpenSSL supports to be used directly as RNGs. It also allows DRBG seeding to be explicitly specified rather than being left to a fall back case. Reviewed-by: Matt Caswell (Merged from https://github.com/openssl/openssl/pull/13455) --- crypto/err/openssl.txt | 2 + crypto/rand/rand_lib.c | 53 ++++- doc/man5/config.pod | 10 + doc/man7/EVP_RAND-SEED-SRC.pod | 87 ++++++++ .../common/include/prov/providercommonerr.h | 1 + providers/common/provider_err.c | 2 + providers/defltprov.c | 1 + .../include/prov/implementations.h | 1 + providers/implementations/rands/build.info | 2 +- providers/implementations/rands/seed_src.c | 192 ++++++++++++++++++ 10 files changed, 348 insertions(+), 3 deletions(-) create mode 100644 doc/man7/EVP_RAND-SEED-SRC.pod create mode 100644 providers/implementations/rands/seed_src.c diff --git a/crypto/err/openssl.txt b/crypto/err/openssl.txt index 491f3a7cdbe20..73f551a3e5145 100644 --- a/crypto/err/openssl.txt +++ b/crypto/err/openssl.txt @@ -2933,6 +2933,8 @@ PROV_R_REQUIRE_CTR_MODE_CIPHER:206:require ctr mode cipher PROV_R_RESEED_ERROR:197:reseed error PROV_R_SEARCH_ONLY_SUPPORTED_FOR_DIRECTORIES:222:\ search only supported for directories +PROV_R_SEED_SOURCES_MUST_NOT_HAVE_A_PARENT:200:\ + seed sources must not have a parent PROV_R_SELF_TEST_KAT_FAILURE:215:self test kat failure PROV_R_SELF_TEST_POST_FAILURE:216:self test post failure PROV_R_TAG_NOTSET:119:tag notset diff --git a/crypto/rand/rand_lib.c b/crypto/rand/rand_lib.c index 73d509a8dc5f2..2ad3cf776fd6b 100644 --- a/crypto/rand/rand_lib.c +++ b/crypto/rand/rand_lib.c @@ -325,6 +325,8 @@ typedef struct rand_global_st { */ CRYPTO_RWLOCK *lock; + EVP_RAND_CTX *seed; + /* * The DRBG * @@ -363,6 +365,10 @@ typedef struct rand_global_st { char *rng_cipher; char *rng_digest; char *rng_propq; + + /* Allow the randomness source to be changed */ + char *seed_name; + char *seed_propq; } RAND_GLOBAL; /* @@ -412,13 +418,16 @@ static void rand_ossl_ctx_free(void *vdgbl) return; CRYPTO_THREAD_lock_free(dgbl->lock); - EVP_RAND_CTX_free(dgbl->primary); CRYPTO_THREAD_cleanup_local(&dgbl->private); CRYPTO_THREAD_cleanup_local(&dgbl->public); + EVP_RAND_CTX_free(dgbl->primary); + EVP_RAND_CTX_free(dgbl->seed); OPENSSL_free(dgbl->rng_name); OPENSSL_free(dgbl->rng_cipher); OPENSSL_free(dgbl->rng_digest); OPENSSL_free(dgbl->rng_propq); + OPENSSL_free(dgbl->seed_name); + OPENSSL_free(dgbl->seed_propq); OPENSSL_free(dgbl); } @@ -452,6 +461,35 @@ static void rand_delete_thread_state(void *arg) EVP_RAND_CTX_free(rand); } +#ifndef FIPS_MODULE +static EVP_RAND_CTX *rand_new_seed(OSSL_LIB_CTX *libctx) +{ + EVP_RAND *rand; + RAND_GLOBAL *dgbl = rand_get_global(libctx); + EVP_RAND_CTX *ctx; + char *name; + + name = dgbl->seed_name != NULL ? dgbl->seed_name : "SEED-SRC"; + rand = EVP_RAND_fetch(libctx, name, dgbl->seed_propq); + if (rand == NULL) { + ERR_raise(ERR_LIB_RAND, RAND_R_UNABLE_TO_FETCH_DRBG); + return NULL; + } + ctx = EVP_RAND_CTX_new(rand, NULL); + EVP_RAND_free(rand); + if (ctx == NULL) { + ERR_raise(ERR_LIB_RAND, RAND_R_UNABLE_TO_CREATE_DRBG); + return NULL; + } + if (!EVP_RAND_instantiate(ctx, 0, 0, NULL, 0)) { + ERR_raise(ERR_LIB_RAND, RAND_R_ERROR_INSTANTIATING_DRBG); + EVP_RAND_CTX_free(ctx); + return NULL; + } + return ctx; +} +#endif + static EVP_RAND_CTX *rand_new_drbg(OSSL_LIB_CTX *libctx, EVP_RAND_CTX *parent, unsigned int reseed_interval, time_t reseed_time_interval) @@ -522,8 +560,13 @@ EVP_RAND_CTX *RAND_get0_primary(OSSL_LIB_CTX *ctx) if (dgbl->primary == NULL) { if (!CRYPTO_THREAD_write_lock(dgbl->lock)) return NULL; +#ifndef FIPS_MODULE + if (dgbl->seed == NULL) + dgbl->seed = rand_new_seed(ctx); +#endif if (dgbl->primary == NULL) - dgbl->primary = rand_new_drbg(ctx, NULL, PRIMARY_RESEED_INTERVAL, + dgbl->primary = rand_new_drbg(ctx, dgbl->seed, + PRIMARY_RESEED_INTERVAL, PRIMARY_RESEED_TIME_INTERVAL); CRYPTO_THREAD_unlock(dgbl->lock); } @@ -644,6 +687,12 @@ static int random_conf_init(CONF_IMODULE *md, const CONF *cnf) } else if (strcasecmp(cval->name, "properties") == 0) { if (!random_set_string(&dgbl->rng_propq, cval->value)) return 0; + } else if (strcasecmp(cval->name, "seed") == 0) { + if (!random_set_string(&dgbl->seed_name, cval->value)) + return 0; + } else if (strcasecmp(cval->name, "seed_properties") == 0) { + if (!random_set_string(&dgbl->seed_propq, cval->value)) + return 0; } else { ERR_raise_data(ERR_LIB_CRYPTO, CRYPTO_R_UNKNOWN_NAME_IN_RANDOM_SECTION, diff --git a/doc/man5/config.pod b/doc/man5/config.pod index 0a28f4ea4b273..45165f20ec60b 100644 --- a/doc/man5/config.pod +++ b/doc/man5/config.pod @@ -438,6 +438,16 @@ generators will use. Other random bit generators ignore this name. This sets the property query used when fetching the random bit generator and any underlying algorithms. +=item B + +This sets the randomness source that should be used. By default B +will be used outside of the FIPS provider. The FIPS provider uses call backs +to access the same randomness sources from outside the validated boundary. + +=item B + +This sets the property query used when fetching the randomness source. + =back =head1 EXAMPLES diff --git a/doc/man7/EVP_RAND-SEED-SRC.pod b/doc/man7/EVP_RAND-SEED-SRC.pod new file mode 100644 index 0000000000000..f301ed25f9fa1 --- /dev/null +++ b/doc/man7/EVP_RAND-SEED-SRC.pod @@ -0,0 +1,87 @@ +=pod + +=head1 NAME + +EVP_RAND-SEED-SRC - The randomness seed source EVP_RAND implementation + +=head1 DESCRIPTION + +Support for deterministic random number generator seeding through the +B API. + +The seed sources used are specified at the time OpenSSL is configured for +building using the B<--with-rand-seed=> option. By default, operating system +randomness sources are used. + +=head2 Identity + +"SEED-SRC" is the name for this implementation; it can be used with the +EVP_RAND_fetch() function. + +=head2 Supported parameters + +The supported parameters are: + +=over 4 + +=item "state" (B) + +=item "strength" (B) + +=item "max_request" (B) + +These parameters work as described in L. + +=back + +=head1 NOTES + +A context for the seed source can be obtained by calling: + + EVP_RAND *rand = EVP_RAND_fetch(NULL, "SEED-SRC", NULL); + EVP_RAND_CTX *rctx = EVP_RAND_CTX_new(rand); + +=head1 EXAMPLES + + EVP_RAND *rand; + EVP_RAND_CTX *seed, *rctx; + unsigned char bytes[100]; + OSSL_PARAM params[2], *p = params; + unsigned int strength = 128; + + /* Create a seed source */ + rand = EVP_RAND_fetch(NULL, "SEED-SRC", NULL); + seed = EVP_RAND_CTX_new(rand, NULL); + EVP_RAND_free(rand); + + /* Feed this into a DRBG */ + rand = EVP_RAND_fetch(NULL, "CTR-DRBG", NULL); + rctx = EVP_RAND_CTX_new(rand, seed); + EVP_RAND_free(rand); + + /* Configure the DRBG */ + *p++ = OSSL_PARAM_construct_utf8_string(OSSL_DRBG_PARAM_CIPHER, + SN_aes_256_ctr, 0); + *p = OSSL_PARAM_construct_end(); + EVP_RAND_set_ctx_params(rctx, params); + + EVP_RAND_generate(rctx, bytes, sizeof(bytes), strength, 0, NULL, 0); + + EVP_RAND_CTX_free(rctx); + EVP_RAND_CTX_free(seed); + +=head1 SEE ALSO + +L, +L + +=head1 COPYRIGHT + +Copyright 2020 The OpenSSL Project Authors. All Rights Reserved. + +Licensed under the Apache License 2.0 (the "License"). You may not use +this file except in compliance with the License. You can obtain a copy +in the file LICENSE in the source distribution or at +L. + +=cut diff --git a/providers/common/include/prov/providercommonerr.h b/providers/common/include/prov/providercommonerr.h index ad1bd20c53966..f044e7b7c78b0 100644 --- a/providers/common/include/prov/providercommonerr.h +++ b/providers/common/include/prov/providercommonerr.h @@ -154,6 +154,7 @@ int err_load_PROV_strings_int(void); # define PROV_R_REQUIRE_CTR_MODE_CIPHER 206 # define PROV_R_RESEED_ERROR 197 # define PROV_R_SEARCH_ONLY_SUPPORTED_FOR_DIRECTORIES 222 +# define PROV_R_SEED_SOURCES_MUST_NOT_HAVE_A_PARENT 200 # define PROV_R_SELF_TEST_KAT_FAILURE 215 # define PROV_R_SELF_TEST_POST_FAILURE 216 # define PROV_R_TAG_NOTSET 119 diff --git a/providers/common/provider_err.c b/providers/common/provider_err.c index fed6018387b3e..3a28eaaa2dce0 100644 --- a/providers/common/provider_err.c +++ b/providers/common/provider_err.c @@ -175,6 +175,8 @@ static const ERR_STRING_DATA PROV_str_reasons[] = { {ERR_PACK(ERR_LIB_PROV, 0, PROV_R_RESEED_ERROR), "reseed error"}, {ERR_PACK(ERR_LIB_PROV, 0, PROV_R_SEARCH_ONLY_SUPPORTED_FOR_DIRECTORIES), "search only supported for directories"}, + {ERR_PACK(ERR_LIB_PROV, 0, PROV_R_SEED_SOURCES_MUST_NOT_HAVE_A_PARENT), + "seed sources must not have a parent"}, {ERR_PACK(ERR_LIB_PROV, 0, PROV_R_SELF_TEST_KAT_FAILURE), "self test kat failure"}, {ERR_PACK(ERR_LIB_PROV, 0, PROV_R_SELF_TEST_POST_FAILURE), diff --git a/providers/defltprov.c b/providers/defltprov.c index 9a662738d8955..3cd7dffee80d9 100644 --- a/providers/defltprov.c +++ b/providers/defltprov.c @@ -362,6 +362,7 @@ static const OSSL_ALGORITHM deflt_rands[] = { { "CTR-DRBG", "provider=default", ossl_drbg_ctr_functions }, { "HASH-DRBG", "provider=default", ossl_drbg_hash_functions }, { "HMAC-DRBG", "provider=default", ossl_drbg_ossl_hmac_functions }, + { "SEED-SRC", "provider=default", ossl_seed_src_functions }, { "TEST-RAND", "provider=default", ossl_test_rng_functions }, { NULL, NULL, NULL } }; diff --git a/providers/implementations/include/prov/implementations.h b/providers/implementations/include/prov/implementations.h index 00178d4ceb4d7..5b6f9131311f5 100644 --- a/providers/implementations/include/prov/implementations.h +++ b/providers/implementations/include/prov/implementations.h @@ -265,6 +265,7 @@ extern const OSSL_DISPATCH ossl_kdf_krb5kdf_functions[]; /* RNGs */ extern const OSSL_DISPATCH ossl_test_rng_functions[]; +extern const OSSL_DISPATCH ossl_seed_src_functions[]; extern const OSSL_DISPATCH ossl_drbg_hash_functions[]; extern const OSSL_DISPATCH ossl_drbg_ossl_hmac_functions[]; extern const OSSL_DISPATCH ossl_drbg_ctr_functions[]; diff --git a/providers/implementations/rands/build.info b/providers/implementations/rands/build.info index 2ca0cdadc7265..b44c1caa8a724 100644 --- a/providers/implementations/rands/build.info +++ b/providers/implementations/rands/build.info @@ -3,4 +3,4 @@ SUBDIRS=seeding $COMMON=drbg.c test_rng.c drbg_ctr.c drbg_hash.c drbg_hmac.c crngt.c SOURCE[../../libfips.a]=$COMMON -SOURCE[../../libnonfips.a]=$COMMON +SOURCE[../../libnonfips.a]=$COMMON seed_src.c diff --git a/providers/implementations/rands/seed_src.c b/providers/implementations/rands/seed_src.c new file mode 100644 index 0000000000000..7080e95fbf263 --- /dev/null +++ b/providers/implementations/rands/seed_src.c @@ -0,0 +1,192 @@ +/* + * Copyright 2020 The OpenSSL Project Authors. All Rights Reserved. + * + * Licensed under the Apache License 2.0 (the "License"). You may not use + * this file except in compliance with the License. You can obtain a copy + * in the file LICENSE in the source distribution or at + * https://www.openssl.org/source/license.html + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include "prov/implementations.h" +#include "prov/provider_ctx.h" +#include "prov/providercommonerr.h" +#include "crypto/rand.h" +#include "crypto/rand_pool.h" + +static OSSL_FUNC_rand_newctx_fn seed_src_new; +static OSSL_FUNC_rand_freectx_fn seed_src_free; +static OSSL_FUNC_rand_instantiate_fn seed_src_instantiate; +static OSSL_FUNC_rand_uninstantiate_fn seed_src_uninstantiate; +static OSSL_FUNC_rand_generate_fn seed_src_generate; +static OSSL_FUNC_rand_reseed_fn seed_src_reseed; +static OSSL_FUNC_rand_gettable_ctx_params_fn seed_src_gettable_ctx_params; +static OSSL_FUNC_rand_get_ctx_params_fn seed_src_get_ctx_params; +static OSSL_FUNC_rand_verify_zeroization_fn seed_src_verify_zeroization; +static OSSL_FUNC_rand_enable_locking_fn seed_src_enable_locking; + +typedef struct { + void *provctx; + int state; +} PROV_SEED_SRC; + +static void *seed_src_new(void *provctx, void *parent, + const OSSL_DISPATCH *parent_dispatch) +{ + PROV_SEED_SRC *s; + + if (parent != NULL) { + ERR_raise(ERR_LIB_PROV, PROV_R_SEED_SOURCES_MUST_NOT_HAVE_A_PARENT); + return NULL; + } + + s = OPENSSL_zalloc(sizeof(*s)); + if (s == NULL) { + ERR_raise(ERR_LIB_PROV, ERR_R_MALLOC_FAILURE); + return NULL; + } + + s->provctx = provctx; + s->state = EVP_RAND_STATE_UNINITIALISED; + return s; +} + +static void seed_src_free(void *vseed) +{ + OPENSSL_free(vseed); +} + +static int seed_src_instantiate(void *vseed, unsigned int strength, + int prediction_resistance, + const unsigned char *pstr, size_t pstr_len) +{ + PROV_SEED_SRC *s = (PROV_SEED_SRC *)vseed; + + s->state = EVP_RAND_STATE_READY; + return 1; +} + +static int seed_src_uninstantiate(void *vseed) +{ + PROV_SEED_SRC *s = (PROV_SEED_SRC *)vseed; + + s->state = EVP_RAND_STATE_UNINITIALISED; + return 1; +} + +static int seed_src_generate(void *vseed, unsigned char *out, size_t outlen, + unsigned int strength, + ossl_unused int prediction_resistance, + ossl_unused const unsigned char *adin, + ossl_unused size_t adin_len) +{ + PROV_SEED_SRC *s = (PROV_SEED_SRC *)vseed; + size_t entropy_available; + RAND_POOL *pool; + + if (s->state != EVP_RAND_STATE_READY) { + ERR_raise(ERR_LIB_PROV, + s->state == EVP_RAND_STATE_ERROR ? PROV_R_IN_ERROR_STATE + : PROV_R_NOT_INSTANTIATED); + return 0; + } + + pool = rand_pool_new(strength, 1, outlen, outlen); + if (pool == NULL) { + ERR_raise(ERR_LIB_PROV, ERR_R_MALLOC_FAILURE); + return 0; + } + + /* Get entropy by polling system entropy sources. */ + entropy_available = ossl_pool_acquire_entropy(pool); + + if (entropy_available > 0) + memcpy(out, rand_pool_detach(pool), rand_pool_length(pool)); + + rand_pool_free(pool); + return entropy_available > 0; +} + +static int seed_src_reseed(void *vseed, + ossl_unused int prediction_resistance, + ossl_unused const unsigned char *ent, + ossl_unused size_t ent_len, + ossl_unused const unsigned char *adin, + ossl_unused size_t adin_len) +{ + PROV_SEED_SRC *s = (PROV_SEED_SRC *)vseed; + + if (s->state != EVP_RAND_STATE_READY) { + ERR_raise(ERR_LIB_PROV, + s->state == EVP_RAND_STATE_ERROR ? PROV_R_IN_ERROR_STATE + : PROV_R_NOT_INSTANTIATED); + return 0; + } + return 1; +} + +static int seed_src_get_ctx_params(void *vseed, OSSL_PARAM params[]) +{ + PROV_SEED_SRC *s = (PROV_SEED_SRC *)vseed; + OSSL_PARAM *p; + + p = OSSL_PARAM_locate(params, OSSL_RAND_PARAM_STATE); + if (p != NULL && !OSSL_PARAM_set_int(p, s->state)) + return 0; + + p = OSSL_PARAM_locate(params, OSSL_RAND_PARAM_STRENGTH); + if (p != NULL && !OSSL_PARAM_set_int(p, 1024)) + return 0; + + p = OSSL_PARAM_locate(params, OSSL_RAND_PARAM_MAX_REQUEST); + if (p != NULL && !OSSL_PARAM_set_size_t(p, 128)) + return 0; + return 1; +} + +static const OSSL_PARAM *seed_src_gettable_ctx_params(ossl_unused void *provctx) +{ + static const OSSL_PARAM known_gettable_ctx_params[] = { + OSSL_PARAM_int(OSSL_RAND_PARAM_STATE, NULL), + OSSL_PARAM_uint(OSSL_RAND_PARAM_STRENGTH, NULL), + OSSL_PARAM_size_t(OSSL_RAND_PARAM_MAX_REQUEST, NULL), + OSSL_PARAM_END + }; + return known_gettable_ctx_params; +} + +static int seed_src_verify_zeroization(ossl_unused void *vseed) +{ + return 1; +} + +static int seed_src_enable_locking(ossl_unused void *vseed) +{ + return 1; +} + +const OSSL_DISPATCH ossl_seed_src_functions[] = { + { OSSL_FUNC_RAND_NEWCTX, (void(*)(void))seed_src_new }, + { OSSL_FUNC_RAND_FREECTX, (void(*)(void))seed_src_free }, + { OSSL_FUNC_RAND_INSTANTIATE, + (void(*)(void))seed_src_instantiate }, + { OSSL_FUNC_RAND_UNINSTANTIATE, + (void(*)(void))seed_src_uninstantiate }, + { OSSL_FUNC_RAND_GENERATE, (void(*)(void))seed_src_generate }, + { OSSL_FUNC_RAND_RESEED, (void(*)(void))seed_src_reseed }, + { OSSL_FUNC_RAND_ENABLE_LOCKING, (void(*)(void))seed_src_enable_locking }, + { OSSL_FUNC_RAND_GETTABLE_CTX_PARAMS, + (void(*)(void))seed_src_gettable_ctx_params }, + { OSSL_FUNC_RAND_GET_CTX_PARAMS, (void(*)(void))seed_src_get_ctx_params }, + { OSSL_FUNC_RAND_VERIFY_ZEROIZATION, + (void(*)(void))seed_src_verify_zeroization }, + { 0, NULL } +};