CTR, HASH and HMAC DRBGs in provider
[openssl.git] / crypto / rand / rand_lib.c
index e76ca2702d908b33e1828fbe5bae40ca0d3ecefc..e7dfb07de21466e07f633f84fcd4562eaba8ff09 100644 (file)
@@ -1,7 +1,7 @@
 /*
- * Copyright 1995-2016 The OpenSSL Project Authors. All Rights Reserved.
+ * Copyright 1995-2020 The OpenSSL Project Authors. All Rights Reserved.
  *
- * Licensed under the OpenSSL license (the "License").  You may not use
+ * 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 <time.h>
 #include "internal/cryptlib.h"
 #include <openssl/opensslconf.h>
-#include "internal/rand_int.h"
+#include "crypto/rand.h"
 #include <openssl/engine.h>
 #include "internal/thread_once.h"
-#include "rand_lcl.h"
+#include "rand_local.h"
+#include "e_os.h"
 
-#ifndef OPENSSL_NO_ENGINE
+#ifndef FIPS_MODULE
+# include "prov/rand_pool.h"
+# include "prov/seeding.h"
+
+# ifndef OPENSSL_NO_ENGINE
 /* non-NULL if default_RAND_meth is ENGINE-provided */
 static ENGINE *funct_ref;
 static CRYPTO_RWLOCK *rand_engine_lock;
-#endif
+# endif
 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;
-
-#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.  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;
-
-    for (i = 0; i < 10; i++) {
-        c = (unsigned char)(OPENSSL_rdtsc() & 0xFF);
-        cb(arg, &c, 1, 0.5);
-    }
-}
-#endif
-
-#ifdef OPENSSL_RAND_SEED_RDCPU
-size_t OPENSSL_ia32_rdseed(void);
-size_t OPENSSL_ia32_rdrand(void);
-
-extern unsigned int OPENSSL_ia32cap_P[];
-
-int rand_read_cpu(RAND_poll_fn cb, void *arg)
-{
-    size_t i, s;
-
-    /* If RDSEED is available, use that. */
-    if ((OPENSSL_ia32cap_P[1] & (1 << 18)) != 0) {
-        for (i = 0; i < RANDOMNESS_NEEDED; i += sizeof(s)) {
-            s = OPENSSL_ia32_rdseed();
-            if (s == 0)
-                break;
-            cb(arg, &s, (int)sizeof(s), sizeof(s));
-        }
-        if (i >= RANDOMNESS_NEEDED)
-            return 1;
-    }
-
-    /* Second choice is RDRAND. */
-    if ((OPENSSL_ia32cap_P[1] & (1 << (62 - 32))) != 0) {
-        for (i = 0; i < RANDOMNESS_NEEDED; i += sizeof(s)) {
-            s = OPENSSL_ia32_rdrand();
-            if (s == 0)
-                break;
-            cb(arg, &s, (int)sizeof(s), sizeof(s));
-        }
-        if (i >= RANDOMNESS_NEEDED)
-            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;
-    }
-
-    /* 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;
-}
+static int rand_inited = 0;
 
-size_t drbg_entropy_from_parent(RAND_DRBG *drbg,
-                                unsigned char **pout,
-                                int entropy, size_t min_len, size_t max_len)
+DEFINE_RUN_ONCE_STATIC(do_rand_init)
 {
-    int st;
-
-    if (min_len > (size_t)drbg->size) {
-        /* Should not happen.  See comment near RANDOMNESS_NEEDED. */
-        min_len = 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)
+# ifndef OPENSSL_NO_ENGINE
+    rand_engine_lock = CRYPTO_THREAD_lock_new();
+    if (rand_engine_lock == NULL)
         return 0;
-    drbg->filled = 1;
-    *pout = drbg->randomness;
-    return min_len;
-}
-
-void drbg_release_entropy(RAND_DRBG *drbg, unsigned char *out)
-{
-    drbg->filled = 0;
-    OPENSSL_cleanse(drbg->randomness, drbg->size);
-}
+# endif
 
+    rand_meth_lock = CRYPTO_THREAD_lock_new();
+    if (rand_meth_lock == NULL)
+        goto err;
 
-/*
- * 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->randomness = OPENSSL_malloc(drbg->size);
-    ret &= 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);
-    OPENSSL_clear_free(drbg->randomness, drbg->size);
-    RAND_DRBG_uninstantiate(drbg);
-}
+    if (!rand_pool_init())
+        goto err;
 
-DEFINE_RUN_ONCE_STATIC(do_rand_init)
-{
-    int ret = 1;
+    rand_inited = 1;
+    return 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;
-    /* TODO: Should this be secure malloc? */
-    rand_bytes.buff = malloc(rand_bytes.size);
-
-    ret &= rand_bytes.buff != NULL;
-    ret &= setup_drbg(&rand_drbg);
-    ret &= setup_drbg(&priv_drbg);
-    return ret;
+ err:
+    CRYPTO_THREAD_lock_free(rand_meth_lock);
+    rand_meth_lock = NULL;
+# ifndef OPENSSL_NO_ENGINE
+    CRYPTO_THREAD_lock_free(rand_engine_lock);
+    rand_engine_lock = NULL;
+# endif
+    return 0;
 }
 
-
 void rand_cleanup_int(void)
 {
     const RAND_METHOD *meth = default_RAND_meth;
 
+    if (!rand_inited)
+        return;
+
     if (meth != NULL && meth->cleanup != NULL)
         meth->cleanup();
     RAND_set_rand_method(NULL);
-#ifndef OPENSSL_NO_ENGINE
+    rand_pool_cleanup();
+# ifndef OPENSSL_NO_ENGINE
     CRYPTO_THREAD_lock_free(rand_engine_lock);
-#endif
+    rand_engine_lock = NULL;
+# endif
     CRYPTO_THREAD_lock_free(rand_meth_lock);
-    CRYPTO_THREAD_lock_free(rand_bytes.lock);
-    OPENSSL_clear_free(rand_bytes.buff, rand_bytes.size);
-    free_drbg(&rand_drbg);
-    free_drbg(&priv_drbg);
+    rand_meth_lock = NULL;
+    rand_inited = 0;
 }
 
 /*
- * 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().
+ * RAND_close_seed_files() ensures that any seed file descriptors are
+ * closed after use.  This only applies to libcrypto/default provider,
+ * it does not apply to other providers.
  */
-static void call_rand_add(void* arg, const void *buf, int num, double r)
+void RAND_keep_random_devices_open(int keep)
 {
-    RAND_add(buf, num, r);
+    if (RUN_ONCE(&rand_init, do_rand_init))
+        rand_pool_keep_random_devices_open(keep);
 }
 
+/*
+ * RAND_poll() reseeds the default RNG using random input
+ *
+ * The random input is obtained from polling various entropy
+ * sources which depend on the operating system and are
+ * configurable via the --with-rand-seed configure option.
+ */
 int RAND_poll(void)
 {
-    return RAND_poll_ex(call_rand_add, NULL);
+    const RAND_METHOD *meth = RAND_get_rand_method();
+    int ret = meth == RAND_OpenSSL();
+    RAND_POOL *pool;
+
+    if (meth == NULL)
+        return 0;
+
+    if (!ret) {
+        /* fill random pool and seed the current legacy RNG */
+        pool = rand_pool_new(RAND_DRBG_STRENGTH, 1,
+                             (RAND_DRBG_STRENGTH + 7) / 8,
+                             RAND_POOL_MAX_LENGTH);
+        if (pool == NULL)
+            return 0;
+
+        if (prov_pool_acquire_entropy(pool) == 0)
+            goto err;
+
+        if (meth->add == NULL
+            || meth->add(rand_pool_buffer(pool),
+                         rand_pool_length(pool),
+                         (rand_pool_entropy(pool) / 8.0)) == 0)
+            goto err;
+
+        ret = 1;
+     err:
+        rand_pool_free(pool);
+    }
+    return ret;
 }
 
 int RAND_set_rand_method(const RAND_METHOD *meth)
@@ -264,10 +137,10 @@ int RAND_set_rand_method(const RAND_METHOD *meth)
         return 0;
 
     CRYPTO_THREAD_write_lock(rand_meth_lock);
-#ifndef OPENSSL_NO_ENGINE
+# ifndef OPENSSL_NO_ENGINE
     ENGINE_finish(funct_ref);
     funct_ref = NULL;
-#endif
+# endif
     default_RAND_meth = meth;
     CRYPTO_THREAD_unlock(rand_meth_lock);
     return 1;
@@ -282,7 +155,7 @@ const RAND_METHOD *RAND_get_rand_method(void)
 
     CRYPTO_THREAD_write_lock(rand_meth_lock);
     if (default_RAND_meth == NULL) {
-#ifndef OPENSSL_NO_ENGINE
+# ifndef OPENSSL_NO_ENGINE
         ENGINE *e;
 
         /* If we have an engine that can do RAND, use it. */
@@ -294,16 +167,16 @@ const RAND_METHOD *RAND_get_rand_method(void)
             ENGINE_finish(e);
             default_RAND_meth = &rand_meth;
         }
-#else
+# else
         default_RAND_meth = &rand_meth;
-#endif
+# endif
     }
     tmp_meth = default_RAND_meth;
     CRYPTO_THREAD_unlock(rand_meth_lock);
     return tmp_meth;
 }
 
-#ifndef OPENSSL_NO_ENGINE
+# if !defined(OPENSSL_NO_ENGINE)
 int RAND_set_rand_engine(ENGINE *engine)
 {
     const RAND_METHOD *tmp_meth = NULL;
@@ -327,13 +200,13 @@ int RAND_set_rand_engine(ENGINE *engine)
     CRYPTO_THREAD_unlock(rand_engine_lock);
     return 1;
 }
-#endif
+# endif
 
 void RAND_seed(const void *buf, int num)
 {
     const RAND_METHOD *meth = RAND_get_rand_method();
 
-    if (meth->seed != NULL)
+    if (meth != NULL && meth->seed != NULL)
         meth->seed(buf, num);
 }
 
@@ -341,55 +214,91 @@ void RAND_add(const void *buf, int num, double randomness)
 {
     const RAND_METHOD *meth = RAND_get_rand_method();
 
-    if (meth->add != NULL)
+    if (meth != NULL && meth->add != NULL)
         meth->add(buf, num, randomness);
 }
 
+# if !defined(OPENSSL_NO_DEPRECATED_1_1_0)
+int RAND_pseudo_bytes(unsigned char *buf, int num)
+{
+    const RAND_METHOD *meth = RAND_get_rand_method();
+
+    if (meth != NULL && meth->pseudorand != NULL)
+        return meth->pseudorand(buf, num);
+    RANDerr(RAND_F_RAND_PSEUDO_BYTES, RAND_R_FUNC_NOT_IMPLEMENTED);
+    return -1;
+}
+# endif
+
+int RAND_status(void)
+{
+    RAND_DRBG *drbg;
+    const RAND_METHOD *meth = RAND_get_rand_method();
+
+    if (meth != NULL && meth != RAND_OpenSSL())
+        return meth->status != NULL ? meth->status() : 0;
+
+    if ((drbg = RAND_DRBG_get0_master()) == NULL || drbg->rand == NULL)
+        return EVP_RAND_STATE_UNINITIALISED;
+    return EVP_RAND_state(drbg->rand) == EVP_RAND_STATE_READY;
+}
+#else  /* !FIPS_MODULE */
+
+const RAND_METHOD *RAND_get_rand_method(void)
+{
+    return NULL;
+}
+#endif /* !FIPS_MODULE */
+
 /*
  * 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)
+int RAND_priv_bytes_ex(OPENSSL_CTX *ctx, unsigned char *buf, int num)
 {
+    RAND_DRBG *drbg;
     const RAND_METHOD *meth = RAND_get_rand_method();
 
-    if (meth != RAND_OpenSSL())
-        return RAND_bytes(buf, num);
+    if (meth != NULL && meth != RAND_OpenSSL()) {
+        if (meth->bytes != NULL)
+            return meth->bytes(buf, num);
+        RANDerr(RAND_F_RAND_PRIV_BYTES_EX, RAND_R_FUNC_NOT_IMPLEMENTED);
+        return -1;
+    }
 
-    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);
+    drbg = OPENSSL_CTX_get0_private_drbg(ctx);
+    if (drbg != NULL)
+        return RAND_DRBG_bytes(drbg, buf, num);
 
+    return 0;
 }
 
-int RAND_bytes(unsigned char *buf, int num)
+int RAND_priv_bytes(unsigned char *buf, int num)
 {
-    const RAND_METHOD *meth = RAND_get_rand_method();
-
-    if (meth->bytes != NULL)
-        return meth->bytes(buf, num);
-    RANDerr(RAND_F_RAND_BYTES, RAND_R_FUNC_NOT_IMPLEMENTED);
-    return -1;
+    return RAND_priv_bytes_ex(NULL, buf, num);
 }
 
-#if OPENSSL_API_COMPAT < 0x10100000L
-int RAND_pseudo_bytes(unsigned char *buf, int num)
+int RAND_bytes_ex(OPENSSL_CTX *ctx, unsigned char *buf, int num)
 {
+    RAND_DRBG *drbg;
     const RAND_METHOD *meth = RAND_get_rand_method();
 
-    if (meth->pseudorand != NULL)
-        return meth->pseudorand(buf, num);
-    return -1;
-}
-#endif
+    if (meth != NULL && meth != RAND_OpenSSL()) {
+        if (meth->bytes != NULL)
+            return meth->bytes(buf, num);
+        RANDerr(RAND_F_RAND_BYTES_EX, RAND_R_FUNC_NOT_IMPLEMENTED);
+        return -1;
+    }
 
-int RAND_status(void)
-{
-    const RAND_METHOD *meth = RAND_get_rand_method();
+    drbg = OPENSSL_CTX_get0_public_drbg(ctx);
+    if (drbg != NULL)
+        return RAND_DRBG_bytes(drbg, buf, num);
 
-    if (meth->status != NULL)
-        return meth->status();
     return 0;
 }
+
+int RAND_bytes(unsigned char *buf, int num)
+{
+    return RAND_bytes_ex(NULL, buf, num);
+}