/*
- * Copyright 1995-2016 The OpenSSL Project Authors. All Rights Reserved.
+ * Copyright 1995-2017 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
static CRYPTO_RWLOCK *rand_meth_lock;
static const RAND_METHOD *default_RAND_meth;
static CRYPTO_ONCE rand_init = CRYPTO_ONCE_STATIC_INIT;
+RAND_BYTES_BUFFER rand_bytes;
+int rand_fork_count;
+#ifdef OPENSSL_RAND_SEED_RDTSC
+/*
+ * IMPORTANT NOTE: It is not currently possible to use this code
+ * because we are not sure about the amount of randomness it provides.
+ * Some SP900 tests have been run, but there is internal skepticism.
+ * So for now this code is not used.
+ */
+# error "RDTSC enabled? Should not be possible!"
+
+/*
+ * Since we get some randomness from the low-order bits of the
+ * high-speec clock, it can help. But don't return a status since
+ * it's not sufficient to indicate whether or not the seeding was
+ * done.
+ */
+void rand_read_tsc(RAND_poll_fn cb, void *arg)
+{
+ unsigned char c;
+ int i;
+
+ if ((OPENSSL_ia32cap_P[0] & (1 << 4)) != 0) {
+ for (i = 0; i < TSC_READ_COUNT; i++) {
+ c = (unsigned char)(OPENSSL_rdtsc() & 0xFF);
+ cb(arg, &c, 1, 0.5);
+ }
+ }
+}
+#endif
+
+#ifdef OPENSSL_RAND_SEED_RDCPU
+size_t OPENSSL_ia32_rdseed_bytes(char *buf, size_t len);
+size_t OPENSSL_ia32_rdrand_bytes(char *buf, size_t len);
+
+extern unsigned int OPENSSL_ia32cap_P[];
+
+int rand_read_cpu(RAND_poll_fn cb, void *arg)
+{
+ char buff[RANDOMNESS_NEEDED];
+
+ /* If RDSEED is available, use that. */
+ if ((OPENSSL_ia32cap_P[2] & (1 << 18)) != 0) {
+ if (OPENSSL_ia32_rdseed_bytes(buff, sizeof(buff)) == sizeof(buff)) {
+ cb(arg, buff, (int)sizeof(buff), sizeof(buff));
+ return 1;
+ }
+ }
+
+ /* Second choice is RDRAND. */
+ if ((OPENSSL_ia32cap_P[1] & (1 << (62 - 32))) != 0) {
+ if (OPENSSL_ia32_rdrand_bytes(buff, sizeof(buff)) == sizeof(buff)) {
+ cb(arg, buff, (int)sizeof(buff), sizeof(buff));
+ return 1;
+ }
+ }
+
+ return 0;
+}
+#endif
+
+
+/*
+ * DRBG has two sets of callbacks; we only discuss the "entropy" one
+ * here. When the DRBG needs additional randomness bits (called entropy
+ * in the NIST document), it calls the get_entropy callback which fills in
+ * a pointer and returns the number of bytes. When the DRBG is finished with
+ * the buffer, it calls the cleanup_entropy callback, with the value of
+ * the buffer that the get_entropy callback filled in.
+ *
+ * Get entropy from the system, via RAND_poll if needed. The |entropy|
+ * is the bits of randomness required, and is expected to fit into a buffer
+ * of |min_len|..|max__len| size. We assume we're getting high-quality
+ * randomness from the system, and that |min_len| bytes will do.
+ */
+size_t drbg_entropy_from_system(RAND_DRBG *drbg,
+ unsigned char **pout,
+ int entropy, size_t min_len, size_t max_len)
+{
+ int i;
+
+
+ if (min_len > (size_t)drbg->size) {
+ /* Should not happen. See comment near RANDOMNESS_NEEDED. */
+ min_len = drbg->size;
+ }
+
+ if (drbg->filled) {
+ /* Re-use what we have. */
+ *pout = drbg->randomness;
+ return drbg->size;
+ }
+
+ drbg->randomness = drbg->secure ? OPENSSL_secure_malloc(drbg->size)
+ : OPENSSL_malloc(drbg->size);
+
+ /* If we don't have enough, try to get more. */
+ CRYPTO_THREAD_write_lock(rand_bytes.lock);
+ for (i = RAND_POLL_RETRIES; rand_bytes.curr < min_len && --i >= 0; ) {
+ CRYPTO_THREAD_unlock(rand_bytes.lock);
+ RAND_poll();
+ CRYPTO_THREAD_write_lock(rand_bytes.lock);
+ }
+
+ /* Get desired amount, but no more than we have. */
+ if (min_len > rand_bytes.curr)
+ min_len = rand_bytes.curr;
+ if (min_len != 0) {
+ memcpy(drbg->randomness, rand_bytes.buff, min_len);
+ drbg->filled = 1;
+ /* Update amount left and shift it down. */
+ rand_bytes.curr -= min_len;
+ if (rand_bytes.curr != 0)
+ memmove(rand_bytes.buff, &rand_bytes.buff[min_len], rand_bytes.curr);
+ }
+ CRYPTO_THREAD_unlock(rand_bytes.lock);
+ *pout = drbg->randomness;
+ return min_len;
+}
+
+size_t drbg_entropy_from_parent(RAND_DRBG *drbg,
+ unsigned char **pout,
+ int entropy, size_t min_len, size_t max_len)
+{
+ int st;
+
+ if (min_len > (size_t)drbg->size) {
+ /* Should not happen. See comment near RANDOMNESS_NEEDED. */
+ min_len = drbg->size;
+ }
+
+ drbg->randomness = drbg->secure ? OPENSSL_secure_malloc(drbg->size)
+ : OPENSSL_malloc(drbg->size);
+
+ /* Get random from parent, include our state as additional input. */
+ st = RAND_DRBG_generate(drbg->parent, drbg->randomness, min_len, 0,
+ (unsigned char *)drbg, sizeof(*drbg));
+ if (st == 0)
+ return 0;
+ drbg->filled = 1;
+ *pout = drbg->randomness;
+ return min_len;
+}
+
+void drbg_release_entropy(RAND_DRBG *drbg, unsigned char *out)
+{
+ drbg->filled = 0;
+ if (drbg->secure)
+ OPENSSL_secure_clear_free(drbg->randomness, drbg->size);
+ else
+ OPENSSL_clear_free(drbg->randomness, drbg->size);
+ drbg->randomness = NULL;
+}
+
+
+/*
+ * Set up a global DRBG.
+ */
+static int setup_drbg(RAND_DRBG *drbg)
+{
+ int ret = 1;
+
+ drbg->lock = CRYPTO_THREAD_lock_new();
+ ret &= drbg->lock != NULL;
+ drbg->size = RANDOMNESS_NEEDED;
+ drbg->secure = CRYPTO_secure_malloc_initialized();
+ drbg->randomness = NULL;
+ /* If you change these parameters, see RANDOMNESS_NEEDED */
+ ret &= RAND_DRBG_set(drbg,
+ NID_aes_128_ctr, RAND_DRBG_FLAG_CTR_USE_DF) == 1;
+ ret &= RAND_DRBG_set_callbacks(drbg, drbg_entropy_from_system,
+ drbg_release_entropy, NULL, NULL) == 1;
+ return ret;
+}
+
+static void free_drbg(RAND_DRBG *drbg)
+{
+ CRYPTO_THREAD_lock_free(drbg->lock);
+ RAND_DRBG_uninstantiate(drbg);
+}
+
+void rand_fork()
+{
+ rand_fork_count++;
+}
DEFINE_RUN_ONCE_STATIC(do_rand_init)
{
int ret = 1;
+
#ifndef OPENSSL_NO_ENGINE
rand_engine_lock = CRYPTO_THREAD_lock_new();
ret &= rand_engine_lock != NULL;
#endif
rand_meth_lock = CRYPTO_THREAD_lock_new();
ret &= rand_meth_lock != NULL;
+
+ rand_bytes.lock = CRYPTO_THREAD_lock_new();
+ ret &= rand_bytes.lock != NULL;
+ rand_bytes.curr = 0;
+ rand_bytes.size = MAX_RANDOMNESS_HELD;
+ rand_bytes.secure = CRYPTO_secure_malloc_initialized();
+ rand_bytes.buff = rand_bytes.secure
+ ? OPENSSL_secure_malloc(rand_bytes.size)
+ : OPENSSL_malloc(rand_bytes.size);
+ ret &= rand_bytes.buff != NULL;
+ ret &= setup_drbg(&rand_drbg);
+ ret &= setup_drbg(&priv_drbg);
return ret;
}
CRYPTO_THREAD_lock_free(rand_engine_lock);
#endif
CRYPTO_THREAD_lock_free(rand_meth_lock);
- rand_drbg_cleanup();
+ CRYPTO_THREAD_lock_free(rand_bytes.lock);
+ if (rand_bytes.secure)
+ OPENSSL_secure_clear_free(rand_bytes.buff, rand_bytes.size);
+ else
+ OPENSSL_clear_free(rand_bytes.buff, rand_bytes.size);
+ free_drbg(&rand_drbg);
+ free_drbg(&priv_drbg);
+}
+
+/*
+ * RAND_poll_ex() gets a function pointer to call when it has random bytes.
+ * RAND_poll() sets the function pointer to be a wrapper that calls RAND_add().
+ */
+static void call_rand_add(void* arg, const void *buf, int num, double r)
+{
+ RAND_add(buf, num, r);
+}
+
+int RAND_poll(void)
+{
+ return RAND_poll_ex(call_rand_add, NULL);
}
int RAND_set_rand_method(const RAND_METHOD *meth)
default_RAND_meth = tmp_meth;
} else {
ENGINE_finish(e);
- default_RAND_meth = &openssl_rand_meth;
+ default_RAND_meth = &rand_meth;
}
#else
- default_RAND_meth = &openssl_rand_meth;
+ default_RAND_meth = &rand_meth;
#endif
}
tmp_meth = default_RAND_meth;
meth->add(buf, num, randomness);
}
+/*
+ * This function is not part of RAND_METHOD, so if we're not using
+ * the default method, then just call RAND_bytes(). Otherwise make
+ * sure we're instantiated and use the private DRBG.
+ */
+int RAND_priv_bytes(unsigned char *buf, int num)
+{
+ const RAND_METHOD *meth = RAND_get_rand_method();
+
+ if (meth != RAND_OpenSSL())
+ return RAND_bytes(buf, num);
+
+ if (priv_drbg.state == DRBG_UNINITIALISED
+ && RAND_DRBG_instantiate(&priv_drbg, NULL, 0) == 0)
+ return 0;
+ return RAND_DRBG_generate(&priv_drbg, buf, num, 0, NULL, 0);
+
+}
+
int RAND_bytes(unsigned char *buf, int num)
{
const RAND_METHOD *meth = RAND_get_rand_method();
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