/* * Copyright 2011-2020 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 */ /* * RAND_DRBG_set is deprecated for public use, but still ok for * internal use. */ #include "internal/deprecated.h" #include #include "internal/nelem.h" #include #include #include #include #include #include #include "../crypto/rand/rand_local.h" #include "../include/crypto/rand.h" #include "../providers/implementations/rands/drbg_local.h" #include "../crypto/evp/evp_local.h" #if defined(_WIN32) # include #endif #if defined(OPENSSL_SYS_UNIX) # include # include # include #endif #include "testutil.h" #include "drbgtest.h" /* * DRBG generate wrappers */ static int gen_bytes(EVP_RAND_CTX *drbg, unsigned char *buf, int num) { const RAND_METHOD *meth = RAND_get_rand_method(); if (meth != NULL && meth != RAND_OpenSSL()) { if (meth->bytes != NULL) return meth->bytes(buf, num); return -1; } if (drbg != NULL) return EVP_RAND_generate(drbg, buf, num, 0, 0, NULL, 0); return 0; } static int rand_bytes(unsigned char *buf, int num) { return gen_bytes(RAND_get0_public(NULL), buf, num); } static int rand_priv_bytes(unsigned char *buf, int num) { return gen_bytes(RAND_get0_private(NULL), buf, num); } /* * DRBG query functions */ static int state(EVP_RAND_CTX *drbg) { return EVP_RAND_state(drbg); } static unsigned int query_rand_uint(EVP_RAND_CTX *drbg, const char *name) { OSSL_PARAM params[2] = { OSSL_PARAM_END, OSSL_PARAM_END }; unsigned int n; *params = OSSL_PARAM_construct_uint(name, &n); if (EVP_RAND_get_ctx_params(drbg, params)) return n; return 0; } #define DRBG_UINT(name) \ static unsigned int name(EVP_RAND_CTX *drbg) \ { \ return query_rand_uint(drbg, #name); \ } DRBG_UINT(reseed_counter) static PROV_DRBG *prov_rand(EVP_RAND_CTX *drbg) { return (PROV_DRBG *)drbg->data; } static void set_reseed_counter(EVP_RAND_CTX *drbg, unsigned int n) { PROV_DRBG *p = prov_rand(drbg); p->reseed_counter = n; } static void inc_reseed_counter(EVP_RAND_CTX *drbg) { set_reseed_counter(drbg, reseed_counter(drbg) + 1); } static time_t reseed_time(EVP_RAND_CTX *drbg) { OSSL_PARAM params[2] = { OSSL_PARAM_END, OSSL_PARAM_END }; time_t t; *params = OSSL_PARAM_construct_time_t(OSSL_DRBG_PARAM_RESEED_TIME, &t); if (EVP_RAND_get_ctx_params(drbg, params)) return t; return 0; } /* * When building the FIPS module, it isn't possible to disable the continuous * RNG tests. Tests that require this are skipped. */ static int crngt_skip(void) { #ifdef FIPS_MODULE return 1; #else return 0; #endif } /* * Disable CRNG testing if it is enabled. * This stub remains to indicate the calling locations where it is necessary. * Once the RNG infrastructure is able to disable these tests, it should be * reconstituted. */ static int disable_crngt(EVP_RAND_CTX *drbg) { return 1; } /* * Generates random output using rand_bytes() and rand_priv_bytes() * and checks whether the three shared DRBGs were reseeded as * expected. * * |expect_success|: expected outcome (as reported by RAND_status()) * |primary|, |public|, |private|: pointers to the three shared DRBGs * |expect_xxx_reseed| = * 1: it is expected that the specified DRBG is reseeded * 0: it is expected that the specified DRBG is not reseeded * -1: don't check whether the specified DRBG was reseeded or not * |reseed_time|: if nonzero, used instead of time(NULL) to set the * |before_reseed| time. */ static int test_drbg_reseed(int expect_success, EVP_RAND_CTX *primary, EVP_RAND_CTX *public, EVP_RAND_CTX *private, int expect_primary_reseed, int expect_public_reseed, int expect_private_reseed, time_t reseed_when ) { unsigned char buf[32]; time_t before_reseed, after_reseed; int expected_state = (expect_success ? DRBG_READY : DRBG_ERROR); unsigned int primary_reseed, public_reseed, private_reseed; /* * step 1: check preconditions */ /* Test whether seed propagation is enabled */ if (!TEST_int_ne(primary_reseed = reseed_counter(primary), 0) || !TEST_int_ne(public_reseed = reseed_counter(public), 0) || !TEST_int_ne(private_reseed = reseed_counter(private), 0)) return 0; /* * step 2: generate random output */ if (reseed_when == 0) reseed_when = time(NULL); /* Generate random output from the public and private DRBG */ before_reseed = expect_primary_reseed == 1 ? reseed_when : 0; if (!TEST_int_eq(rand_bytes(buf, sizeof(buf)), expect_success) || !TEST_int_eq(rand_priv_bytes(buf, sizeof(buf)), expect_success)) return 0; after_reseed = time(NULL); /* * step 3: check postconditions */ /* Test whether reseeding succeeded as expected */ if (!TEST_int_eq(state(primary), expected_state) || !TEST_int_eq(state(public), expected_state) || !TEST_int_eq(state(private), expected_state)) return 0; if (expect_primary_reseed >= 0) { /* Test whether primary DRBG was reseeded as expected */ if (!TEST_int_ge(reseed_counter(primary), primary_reseed)) return 0; } if (expect_public_reseed >= 0) { /* Test whether public DRBG was reseeded as expected */ if (!TEST_int_ge(reseed_counter(public), public_reseed) || !TEST_uint_ge(reseed_counter(public), reseed_counter(primary))) return 0; } if (expect_private_reseed >= 0) { /* Test whether public DRBG was reseeded as expected */ if (!TEST_int_ge(reseed_counter(private), private_reseed) || !TEST_uint_ge(reseed_counter(private), reseed_counter(primary))) return 0; } if (expect_success == 1) { /* Test whether reseed time of primary DRBG is set correctly */ if (!TEST_time_t_le(before_reseed, reseed_time(primary)) || !TEST_time_t_le(reseed_time(primary), after_reseed)) return 0; /* Test whether reseed times of child DRBGs are synchronized with primary */ if (!TEST_time_t_ge(reseed_time(public), reseed_time(primary)) || !TEST_time_t_ge(reseed_time(private), reseed_time(primary))) return 0; } else { ERR_clear_error(); } return 1; } #if defined(OPENSSL_SYS_UNIX) /* * Test whether primary, public and private DRBG are reseeded after * forking the process. */ static int test_drbg_reseed_after_fork(EVP_RAND_CTX *primary, EVP_RAND_CTX *public, EVP_RAND_CTX *private) { pid_t pid; int status=0; pid = fork(); if (!TEST_int_ge(pid, 0)) return 0; if (pid > 0) { /* I'm the parent; wait for the child and check its exit code */ return TEST_int_eq(waitpid(pid, &status, 0), pid) && TEST_int_eq(status, 0); } /* I'm the child; check whether all three DRBGs reseed. */ if (!TEST_true(test_drbg_reseed(1, primary, public, private, 1, 1, 1, 0))) status = 1; exit(status); } #endif /* * Test whether the default rand_method (RAND_OpenSSL()) is * setup correctly, in particular whether reseeding works * as designed. */ static int test_rand_drbg_reseed(void) { EVP_RAND_CTX *primary, *public, *private; unsigned char rand_add_buf[256]; int rv = 0; time_t before_reseed; if (crngt_skip()) return TEST_skip("CRNGT cannot be disabled"); /* Check whether RAND_OpenSSL() is the default method */ if (!TEST_ptr_eq(RAND_get_rand_method(), RAND_OpenSSL())) return 0; /* All three DRBGs should be non-null */ if (!TEST_ptr(primary = RAND_get0_primary(NULL)) || !TEST_ptr(public = RAND_get0_public(NULL)) || !TEST_ptr(private = RAND_get0_private(NULL))) return 0; /* There should be three distinct DRBGs, two of them chained to primary */ if (!TEST_ptr_ne(public, private) || !TEST_ptr_ne(public, primary) || !TEST_ptr_ne(private, primary) || !TEST_ptr_eq(prov_rand(public)->parent, prov_rand(primary)) || !TEST_ptr_eq(prov_rand(private)->parent, prov_rand(primary))) return 0; /* Disable CRNG testing for the primary DRBG */ if (!TEST_true(disable_crngt(primary))) return 0; /* uninstantiate the three global DRBGs */ EVP_RAND_uninstantiate(primary); EVP_RAND_uninstantiate(private); EVP_RAND_uninstantiate(public); /* * Test initial seeding of shared DRBGs */ if (!TEST_true(test_drbg_reseed(1, primary, public, private, 1, 1, 1, 0))) goto error; /* * Test initial state of shared DRBGs */ if (!TEST_true(test_drbg_reseed(1, primary, public, private, 0, 0, 0, 0))) goto error; /* * Test whether the public and private DRBG are both reseeded when their * reseed counters differ from the primary's reseed counter. */ inc_reseed_counter(primary); if (!TEST_true(test_drbg_reseed(1, primary, public, private, 0, 1, 1, 0))) goto error; /* * Test whether the public DRBG is reseeded when its reseed counter differs * from the primary's reseed counter. */ inc_reseed_counter(primary); inc_reseed_counter(private); if (!TEST_true(test_drbg_reseed(1, primary, public, private, 0, 1, 0, 0))) goto error; /* * Test whether the private DRBG is reseeded when its reseed counter differs * from the primary's reseed counter. */ inc_reseed_counter(primary); inc_reseed_counter(public); if (!TEST_true(test_drbg_reseed(1, primary, public, private, 0, 0, 1, 0))) goto error; #if defined(OPENSSL_SYS_UNIX) if (!TEST_true(test_drbg_reseed_after_fork(primary, public, private))) goto error; #endif /* fill 'randomness' buffer with some arbitrary data */ memset(rand_add_buf, 'r', sizeof(rand_add_buf)); #ifndef FIPS_MODULE /* * Test whether all three DRBGs are reseeded by RAND_add(). * The before_reseed time has to be measured here and passed into the * test_drbg_reseed() test, because the primary DRBG gets already reseeded * in RAND_add(), whence the check for the condition * before_reseed <= reseed_time(primary) will fail if the time value happens * to increase between the RAND_add() and the test_drbg_reseed() call. */ before_reseed = time(NULL); RAND_add(rand_add_buf, sizeof(rand_add_buf), sizeof(rand_add_buf)); if (!TEST_true(test_drbg_reseed(1, primary, public, private, 1, 1, 1, before_reseed))) goto error; #else /* FIPS_MODULE */ /* * In FIPS mode, random data provided by the application via RAND_add() * is not considered a trusted entropy source. It is only treated as * additional_data and no reseeding is forced. This test assures that * no reseeding occurs. */ before_reseed = time(NULL); RAND_add(rand_add_buf, sizeof(rand_add_buf), sizeof(rand_add_buf)); if (!TEST_true(test_drbg_reseed(1, primary, public, private, 0, 0, 0, before_reseed))) goto error; #endif rv = 1; error: return rv; } #if defined(OPENSSL_THREADS) static int multi_thread_rand_bytes_succeeded = 1; static int multi_thread_rand_priv_bytes_succeeded = 1; static int set_reseed_time_interval(EVP_RAND_CTX *drbg, int t) { OSSL_PARAM params[2]; params[0] = OSSL_PARAM_construct_int(OSSL_DRBG_PARAM_RESEED_TIME_INTERVAL, &t); params[1] = OSSL_PARAM_construct_end(); return EVP_RAND_set_ctx_params(drbg, params); } static void run_multi_thread_test(void) { unsigned char buf[256]; time_t start = time(NULL); EVP_RAND_CTX *public = NULL, *private = NULL; if (!TEST_ptr(public = RAND_get0_public(NULL)) || !TEST_ptr(private = RAND_get0_private(NULL)) || !TEST_true(set_reseed_time_interval(private, 1)) || !TEST_true(set_reseed_time_interval(public, 1))) { multi_thread_rand_bytes_succeeded = 0; return; } do { if (rand_bytes(buf, sizeof(buf)) <= 0) multi_thread_rand_bytes_succeeded = 0; if (rand_priv_bytes(buf, sizeof(buf)) <= 0) multi_thread_rand_priv_bytes_succeeded = 0; } while (time(NULL) - start < 5); } # if defined(OPENSSL_SYS_WINDOWS) typedef HANDLE thread_t; static DWORD WINAPI thread_run(LPVOID arg) { run_multi_thread_test(); /* * Because we're linking with a static library, we must stop each * thread explicitly, or so says OPENSSL_thread_stop(3) */ OPENSSL_thread_stop(); return 0; } static int run_thread(thread_t *t) { *t = CreateThread(NULL, 0, thread_run, NULL, 0, NULL); return *t != NULL; } static int wait_for_thread(thread_t thread) { return WaitForSingleObject(thread, INFINITE) == 0; } # else typedef pthread_t thread_t; static void *thread_run(void *arg) { run_multi_thread_test(); /* * Because we're linking with a static library, we must stop each * thread explicitly, or so says OPENSSL_thread_stop(3) */ OPENSSL_thread_stop(); return NULL; } static int run_thread(thread_t *t) { return pthread_create(t, NULL, thread_run, NULL) == 0; } static int wait_for_thread(thread_t thread) { return pthread_join(thread, NULL) == 0; } # endif /* * The main thread will also run the test, so we'll have THREADS+1 parallel * tests running */ # define THREADS 3 static int test_multi_thread(void) { thread_t t[THREADS]; int i; for (i = 0; i < THREADS; i++) run_thread(&t[i]); run_multi_thread_test(); for (i = 0; i < THREADS; i++) wait_for_thread(t[i]); if (!TEST_true(multi_thread_rand_bytes_succeeded)) return 0; if (!TEST_true(multi_thread_rand_priv_bytes_succeeded)) return 0; return 1; } #endif static EVP_RAND_CTX *new_drbg(EVP_RAND_CTX *parent) { OSSL_PARAM params[2]; EVP_RAND *rand = NULL; EVP_RAND_CTX *drbg = NULL; params[0] = OSSL_PARAM_construct_utf8_string(OSSL_DRBG_PARAM_CIPHER, "AES-256-CTR", 0); params[1] = OSSL_PARAM_construct_end(); if (!TEST_ptr(rand = EVP_RAND_fetch(NULL, "CTR-DRBG", NULL)) || !TEST_ptr(drbg = EVP_RAND_CTX_new(rand, parent)) || !TEST_true(EVP_RAND_set_ctx_params(drbg, params))) { EVP_RAND_CTX_free(drbg); drbg = NULL; } EVP_RAND_free(rand); return drbg; } static int test_rand_drbg_prediction_resistance(void) { EVP_RAND_CTX *x = NULL, *y = NULL, *z = NULL; unsigned char buf1[51], buf2[sizeof(buf1)]; int ret = 0, xreseed, yreseed, zreseed; if (crngt_skip()) return TEST_skip("CRNGT cannot be disabled"); /* Initialise a three long DRBG chain */ if (!TEST_ptr(x = new_drbg(NULL)) || !TEST_true(disable_crngt(x)) || !TEST_true(EVP_RAND_instantiate(x, 0, 0, NULL, 0)) || !TEST_ptr(y = new_drbg(x)) || !TEST_true(EVP_RAND_instantiate(y, 0, 0, NULL, 0)) || !TEST_ptr(z = new_drbg(y)) || !TEST_true(EVP_RAND_instantiate(z, 0, 0, NULL, 0))) goto err; /* * During a normal reseed, only the last DRBG in the chain should * be reseeded. */ inc_reseed_counter(y); xreseed = reseed_counter(x); yreseed = reseed_counter(y); zreseed = reseed_counter(z); if (!TEST_true(EVP_RAND_reseed(z, 0, NULL, 0, NULL, 0)) || !TEST_int_eq(reseed_counter(x), xreseed) || !TEST_int_eq(reseed_counter(y), yreseed) || !TEST_int_gt(reseed_counter(z), zreseed)) goto err; /* * When prediction resistance is requested, the request should be * propagated to the primary, so that the entire DRBG chain reseeds. */ zreseed = reseed_counter(z); if (!TEST_true(EVP_RAND_reseed(z, 1, NULL, 0, NULL, 0)) || !TEST_int_gt(reseed_counter(x), xreseed) || !TEST_int_gt(reseed_counter(y), yreseed) || !TEST_int_gt(reseed_counter(z), zreseed)) goto err; /* * During a normal generate, only the last DRBG should be reseed */ inc_reseed_counter(y); xreseed = reseed_counter(x); yreseed = reseed_counter(y); zreseed = reseed_counter(z); if (!TEST_true(EVP_RAND_generate(z, buf1, sizeof(buf1), 0, 0, NULL, 0)) || !TEST_int_eq(reseed_counter(x), xreseed) || !TEST_int_eq(reseed_counter(y), yreseed) || !TEST_int_gt(reseed_counter(z), zreseed)) goto err; /* * When a prediction resistant generate is requested, the request * should be propagated to the primary, reseeding the entire DRBG chain. */ zreseed = reseed_counter(z); if (!TEST_true(EVP_RAND_generate(z, buf2, sizeof(buf2), 0, 1, NULL, 0)) || !TEST_int_gt(reseed_counter(x), xreseed) || !TEST_int_gt(reseed_counter(y), yreseed) || !TEST_int_gt(reseed_counter(z), zreseed) || !TEST_mem_ne(buf1, sizeof(buf1), buf2, sizeof(buf2))) goto err; /* Verify that a normal reseed still only reseeds the last DRBG */ inc_reseed_counter(y); xreseed = reseed_counter(x); yreseed = reseed_counter(y); zreseed = reseed_counter(z); if (!TEST_true(EVP_RAND_reseed(z, 0, NULL, 0, NULL, 0)) || !TEST_int_eq(reseed_counter(x), xreseed) || !TEST_int_eq(reseed_counter(y), yreseed) || !TEST_int_gt(reseed_counter(z), zreseed)) goto err; ret = 1; err: EVP_RAND_CTX_free(z); EVP_RAND_CTX_free(y); EVP_RAND_CTX_free(x); return ret; } int setup_tests(void) { ADD_TEST(test_rand_drbg_reseed); ADD_TEST(test_rand_drbg_prediction_resistance); #if defined(OPENSSL_THREADS) ADD_TEST(test_multi_thread); #endif return 1; }