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|
/*
* 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 <string.h>
#include "internal/nelem.h"
#include <openssl/crypto.h>
#include <openssl/err.h>
#include <openssl/rand.h>
#include <openssl/obj_mac.h>
#include <openssl/evp.h>
#include <openssl/aes.h>
#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 <windows.h>
#endif
#if defined(OPENSSL_SYS_UNIX)
# include <sys/types.h>
# include <sys/wait.h>
# include <unistd.h>
#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;
}
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