rand_drbg: remove RAND_DRBG.

The RAND_DRBG API did not fit well into the new provider concept as
implemented by EVP_RAND and EVP_RAND_CTX. The main reason is that the
RAND_DRBG API is a mixture of 'front end' and 'back end' API calls
and some of its API calls are rather low-level. This holds in particular
for the callback mechanism (RAND_DRBG_set_callbacks()) and the RAND_DRBG
type changing mechanism (RAND_DRBG_set()).

Adding a compatibility layer to continue supporting the RAND_DRBG API as
a legacy API for a regular deprecation period turned out to come at the
price of complicating the new provider API unnecessarily. Since the
RAND_DRBG API exists only since version 1.1.1, it was decided by the OMC
to drop it entirely.

Other related changes:

Use RNG instead of DRBG in EVP_RAND documentation.  The documentation was
using DRBG in places where it should have been RNG or CSRNG.

Move the RAND_DRBG(7) documentation to EVP_RAND(7).

Reviewed-by: Matthias St. Pierre <Matthias.St.Pierre@ncp-e.com>
(Merged from https://github.com/openssl/openssl/pull/12509)

52 files changed, 716 insertions, 19796 deletions

diff --git a/CHANGES.md b/CHANGES.md
index 75ecfc22f4..3ecdd5d99b 100644
--- a/CHANGES.md
+++ b/CHANGES.md
@@ -23,6 +23,22 @@ OpenSSL 3.0
 
 ### Changes between 1.1.1 and 3.0 [xx XXX xxxx]
 
+ * Remove the RAND_DRBG API
+
+   The RAND_DRBG API did not fit well into the new provider concept as
+   implemented by EVP_RAND and EVP_RAND_CTX. The main reason is that the
+   RAND_DRBG API is a mixture of 'front end' and 'back end' API calls
+   and some of its API calls are rather low-level. This holds in particular
+   for the callback mechanism (RAND_DRBG_set_callbacks()).
+
+   Adding a compatibility layer to continue supporting the RAND_DRBG API as
+   a legacy API for a regular deprecation period turned out to come at the
+   price of complicating the new provider API unnecessarily. Since the
+   RAND_DRBG API exists only since version 1.1.1, it was decided by the OMC
+   to drop it entirely.
+
+   *Paul Dale and Matthias St. Pierre*
+
  * Allow SSL_set1_host() and SSL_add1_host() to take IP literal addresses
    as well as actual hostnames.
 
diff --git a/NEWS.md b/NEWS.md
index 801016f2b5..e40b2932b3 100644
--- a/NEWS.md
+++ b/NEWS.md
@@ -20,6 +20,7 @@ OpenSSL 3.0
 
 ### Major changes between OpenSSL 1.1.1 and OpenSSL 3.0 [under development]
 
+  * Remove the `RAND_DRBG` API.
   * Deprecated the `ENGINE` API.
   * Added `OPENSSL_CTX`, a libcrypto library context.
   * Interactive mode is removed from the 'openssl' program.
diff --git a/crypto/err/openssl.txt b/crypto/err/openssl.txt
index cbfc495a0a..af19ab26cd 100644
--- a/crypto/err/openssl.txt
+++ b/crypto/err/openssl.txt
@@ -2989,6 +2989,8 @@ RAND_R_RESEED_ERROR:118:reseed error
 RAND_R_SELFTEST_FAILURE:119:selftest failure
 RAND_R_TOO_LITTLE_NONCE_REQUESTED:135:too little nonce requested
 RAND_R_TOO_MUCH_NONCE_REQUESTED:136:too much nonce requested
+RAND_R_UNABLE_TO_CREATE_DRBG:143:unable to create drbg
+RAND_R_UNABLE_TO_FETCH_DRBG:144:unable to fetch drbg
 RAND_R_UNABLE_TO_GET_PARENT_RESEED_PROP_COUNTER:141:\
 	unable to get parent reseed prop counter
 RAND_R_UNABLE_TO_GET_PARENT_STRENGTH:138:unable to get parent strength
@@ -3467,13 +3469,13 @@ X509V3_R_INCORRECT_POLICY_SYNTAX_TAG:152:incorrect policy syntax tag
 X509V3_R_INVALID_ASNUMBER:162:invalid asnumber
 X509V3_R_INVALID_ASRANGE:163:invalid asrange
 X509V3_R_INVALID_BOOLEAN_STRING:104:invalid boolean string
+X509V3_R_INVALID_EMPTY_NAME:108:invalid empty name
 X509V3_R_INVALID_EXTENSION_STRING:105:invalid extension string
 X509V3_R_INVALID_INHERITANCE:165:invalid inheritance
 X509V3_R_INVALID_IPADDRESS:166:invalid ipaddress
 X509V3_R_INVALID_MULTIPLE_RDNS:161:invalid multiple rdns
 X509V3_R_INVALID_NAME:106:invalid name
 X509V3_R_INVALID_NULL_ARGUMENT:107:invalid null argument
-X509V3_R_INVALID_EMPTY_NAME:108:invalid empty name
 X509V3_R_INVALID_NULL_VALUE:109:invalid null value
 X509V3_R_INVALID_NUMBER:140:invalid number
 X509V3_R_INVALID_NUMBERS:141:invalid numbers
diff --git a/crypto/evp/e_aria.c b/crypto/evp/e_aria.c
index 9720fcb7e5..ba654f6b94 100644
--- a/crypto/evp/e_aria.c
+++ b/crypto/evp/e_aria.c
@@ -13,7 +13,6 @@
 # include <openssl/evp.h>
 # include <openssl/modes.h>
 # include <openssl/rand.h>
-# include <openssl/rand_drbg.h>
 # include "crypto/aria.h"
 # include "crypto/evp.h"
 # include "crypto/modes.h"
diff --git a/crypto/evp/evp_enc.c b/crypto/evp/evp_enc.c
index 6ade73e978..2f00f9a13b 100644
--- a/crypto/evp/evp_enc.c
+++ b/crypto/evp/evp_enc.c
@@ -16,7 +16,6 @@
 #include <openssl/evp.h>
 #include <openssl/err.h>
 #include <openssl/rand.h>
-#include <openssl/rand_drbg.h>
 #include <openssl/engine.h>
 #include <openssl/params.h>
 #include <openssl/core_names.h>
diff --git a/crypto/evp/evp_local.h b/crypto/evp/evp_local.h
index 99c53484a6..1e1d689070 100644
--- a/crypto/evp/evp_local.h
+++ b/crypto/evp/evp_local.h
@@ -71,33 +71,6 @@ struct evp_rand_ctx_st {
     void *data;                 /* Algorithm-specific data */
 } /* EVP_RAND_CTX */ ;
 
-struct evp_rand_st {
-    OSSL_PROVIDER *prov;
-    int name_id;
-    CRYPTO_REF_COUNT refcnt;
-    CRYPTO_RWLOCK *refcnt_lock;
-
-    const OSSL_DISPATCH *dispatch;
-    OSSL_FUNC_rand_newctx_fn *newctx;
-    OSSL_FUNC_rand_freectx_fn *freectx;
-    OSSL_FUNC_rand_instantiate_fn *instantiate;
-    OSSL_FUNC_rand_uninstantiate_fn *uninstantiate;
-    OSSL_FUNC_rand_generate_fn *generate;
-    OSSL_FUNC_rand_reseed_fn *reseed;
-    OSSL_FUNC_rand_nonce_fn *nonce;
-    OSSL_FUNC_rand_enable_locking_fn *enable_locking;
-    OSSL_FUNC_rand_lock_fn *lock;
-    OSSL_FUNC_rand_unlock_fn *unlock;
-    OSSL_FUNC_rand_gettable_params_fn *gettable_params;
-    OSSL_FUNC_rand_gettable_ctx_params_fn *gettable_ctx_params;
-    OSSL_FUNC_rand_settable_ctx_params_fn *settable_ctx_params;
-    OSSL_FUNC_rand_get_params_fn *get_params;
-    OSSL_FUNC_rand_get_ctx_params_fn *get_ctx_params;
-    OSSL_FUNC_rand_set_ctx_params_fn *set_ctx_params;
-    OSSL_FUNC_rand_set_callbacks_fn *set_callbacks;
-    OSSL_FUNC_rand_verify_zeroization_fn *verify_zeroization;
-} /* EVP_RAND */ ;
-
 struct evp_keymgmt_st {
     int id;                      /* libcrypto internal */
 
diff --git a/crypto/evp/evp_rand.c b/crypto/evp/evp_rand.c
index 9056f6d20b..0e5e8c11f9 100644
--- a/crypto/evp/evp_rand.c
+++ b/crypto/evp/evp_rand.c
@@ -25,6 +25,32 @@
 #include "internal/provider.h"
 #include "evp_local.h"
 
+struct evp_rand_st {
+    OSSL_PROVIDER *prov;
+    int name_id;
+    CRYPTO_REF_COUNT refcnt;
+    CRYPTO_RWLOCK *refcnt_lock;
+
+    const OSSL_DISPATCH *dispatch;
+    OSSL_FUNC_rand_newctx_fn *newctx;
+    OSSL_FUNC_rand_freectx_fn *freectx;
+    OSSL_FUNC_rand_instantiate_fn *instantiate;
+    OSSL_FUNC_rand_uninstantiate_fn *uninstantiate;
+    OSSL_FUNC_rand_generate_fn *generate;
+    OSSL_FUNC_rand_reseed_fn *reseed;
+    OSSL_FUNC_rand_nonce_fn *nonce;
+    OSSL_FUNC_rand_enable_locking_fn *enable_locking;
+    OSSL_FUNC_rand_lock_fn *lock;
+    OSSL_FUNC_rand_unlock_fn *unlock;
+    OSSL_FUNC_rand_gettable_params_fn *gettable_params;
+    OSSL_FUNC_rand_gettable_ctx_params_fn *gettable_ctx_params;
+    OSSL_FUNC_rand_settable_ctx_params_fn *settable_ctx_params;
+    OSSL_FUNC_rand_get_params_fn *get_params;
+    OSSL_FUNC_rand_get_ctx_params_fn *get_ctx_params;
+    OSSL_FUNC_rand_set_ctx_params_fn *set_ctx_params;
+    OSSL_FUNC_rand_verify_zeroization_fn *verify_zeroization;
+} /* EVP_RAND */ ;
+
 static int evp_rand_up_ref(void *vrand)
 {
     EVP_RAND *rand = (EVP_RAND *)vrand;
@@ -144,11 +170,6 @@ static void *evp_rand_from_dispatch(int name_id,
                 break;
             rand->nonce = OSSL_FUNC_rand_nonce(fns);
             break;
-        case OSSL_FUNC_RAND_SET_CALLBACKS:
-            if (rand->set_callbacks != NULL)
-                break;
-            rand->set_callbacks = OSSL_FUNC_rand_set_callbacks(fns);
-            break;
         case OSSL_FUNC_RAND_ENABLE_LOCKING:
             if (rand->enable_locking != NULL)
                 break;
@@ -579,38 +600,6 @@ int EVP_RAND_state(EVP_RAND_CTX *ctx)
     return state;
 }
 
-static int evp_rand_set_callbacks_locked(EVP_RAND_CTX *ctx,
-                                         OSSL_INOUT_CALLBACK *get_entropy,
-                                         OSSL_CALLBACK *cleanup_entropy,
-                                         OSSL_INOUT_CALLBACK *get_nonce,
-                                         OSSL_CALLBACK *cleanup_nonce,
-                                         void *arg)
-{
-    if (ctx->meth->set_callbacks == NULL) {
-        EVPerr(0, EVP_R_UNABLE_TO_SET_CALLBACKS);
-        return 0;
-    }
-    ctx->meth->set_callbacks(ctx->data, get_entropy, cleanup_entropy,
-                             get_nonce, cleanup_nonce, arg);
-    return 1;
-}
-
-int EVP_RAND_set_callbacks(EVP_RAND_CTX *ctx,
-                           OSSL_INOUT_CALLBACK *get_entropy,
-                           OSSL_CALLBACK *cleanup_entropy,
-                           OSSL_INOUT_CALLBACK *get_nonce,
-                           OSSL_CALLBACK *cleanup_nonce, void *arg)
-{
-    int res;
-
-    if (!evp_rand_lock(ctx))
-        return 0;
-    res = evp_rand_set_callbacks_locked(ctx, get_entropy, cleanup_entropy,
-                                        get_nonce, cleanup_nonce, arg);
-    evp_rand_unlock(ctx);
-    return res;
-}
-
 static int evp_rand_verify_zeroization_locked(EVP_RAND_CTX *ctx)
 {
     if (ctx->meth->verify_zeroization != NULL)
diff --git a/crypto/rand/build.info b/crypto/rand/build.info
index 7776ca8820..f58a026f3b 100644
--- a/crypto/rand/build.info
+++ b/crypto/rand/build.info
@@ -1,6 +1,6 @@
 LIBS=../../libcrypto
 
-$COMMON=drbg_lib.c rand_lib.c
+$COMMON=rand_lib.c rand_meth.c
 $CRYPTO=randfile.c rand_err.c rand_deprecated.c
 
 IF[{- !$disabled{'egd'} -}]
diff --git a/crypto/rand/drbg_lib.c b/crypto/rand/drbg_lib.c
deleted file mode 100644
index d2566920cd..0000000000
--- a/crypto/rand/drbg_lib.c
+++ /dev/null
@@ -1,1016 +0,0 @@
-/*
- * 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 <openssl/crypto.h>
-#include <openssl/err.h>
-#include <openssl/rand.h>
-#include <openssl/core_names.h>
-#include "rand_local.h"
-#include "internal/thread_once.h"
-#include "crypto/rand.h"
-#include "crypto/cryptlib.h"
-
-/*
- * Support framework for NIST SP 800-90A DRBG
- *
- * See manual page RAND_DRBG(7) for a general overview.
- *
- * The OpenSSL model is to have new and free functions, and that new
- * does all initialization.  That is not the NIST model, which has
- * instantiation and un-instantiate, and re-use within a new/free
- * lifecycle.  (No doubt this comes from the desire to support hardware
- * DRBG, where allocation of resources on something like an HSM is
- * a much bigger deal than just re-setting an allocated resource.)
- */
-
-
-typedef struct drbg_global_st {
-    /*
-     * The three shared DRBG instances
-     *
-     * There are three shared DRBG instances: <primary>, <public>, and
-     * <private>.  The <public> and <private> DRBGs are secondary ones.
-     * These are used for non-secret (e.g. nonces) and secret
-     * (e.g. private keys) data respectively.
-     */
-    CRYPTO_RWLOCK *lock;
-
-    /*
-     * The <primary> DRBG
-     *
-     * Not used directly by the application, only for reseeding the two other
-     * DRBGs. It reseeds itself by pulling either randomness from os entropy
-     * sources or by consuming randomness which was added by RAND_add().
-     *
-     * The <primary> DRBG is a global instance which is accessed concurrently by
-     * all threads. The necessary locking is managed automatically by its child
-     * DRBG instances during reseeding.
-     */
-    RAND_DRBG *primary_drbg;
-    /*
-     * The <public> DRBG
-     *
-     * Used by default for generating random bytes using RAND_bytes().
-     *
-     * The <public> secondary DRBG is thread-local, i.e., there is one instance
-     * per thread.
-     */
-    CRYPTO_THREAD_LOCAL public_drbg;
-    /*
-     * The <private> DRBG
-     *
-     * Used by default for generating private keys using RAND_priv_bytes()
-     *
-     * The <private> secondary DRBG is thread-local, i.e., there is one
-     * instance per thread.
-     */
-    CRYPTO_THREAD_LOCAL private_drbg;
-} DRBG_GLOBAL;
-
-#define RAND_DRBG_TYPE_FLAGS    ( \
-    RAND_DRBG_FLAG_PRIMARY | RAND_DRBG_FLAG_PUBLIC | RAND_DRBG_FLAG_PRIVATE )
-
-#define RAND_DRBG_TYPE_PRIMARY                    0
-#define RAND_DRBG_TYPE_PUBLIC                     1
-#define RAND_DRBG_TYPE_PRIVATE                    2
-
-/* Defaults */
-static int rand_drbg_type[3] = {
-    RAND_DRBG_TYPE, /* Primary */
-    RAND_DRBG_TYPE, /* Public */
-    RAND_DRBG_TYPE  /* Private */
-};
-static unsigned int rand_drbg_flags[3] = {
-    RAND_DRBG_FLAGS | RAND_DRBG_FLAG_PRIMARY, /* Primary */
-    RAND_DRBG_FLAGS | RAND_DRBG_FLAG_PUBLIC,  /* Public */
-    RAND_DRBG_FLAGS | RAND_DRBG_FLAG_PRIVATE  /* Private */
-};
-
-static unsigned int primary_reseed_interval = PRIMARY_RESEED_INTERVAL;
-static unsigned int secondary_reseed_interval = SECONDARY_RESEED_INTERVAL;
-
-static time_t primary_reseed_time_interval = PRIMARY_RESEED_TIME_INTERVAL;
-static time_t secondary_reseed_time_interval = SECONDARY_RESEED_TIME_INTERVAL;
-
-/* A logical OR of all used DRBG flag bits (currently there is only one) */
-static const unsigned int rand_drbg_used_flags =
-    RAND_DRBG_FLAG_CTR_NO_DF | RAND_DRBG_FLAG_HMAC | RAND_DRBG_TYPE_FLAGS;
-
-
-static RAND_DRBG *drbg_setup(OPENSSL_CTX *ctx, RAND_DRBG *parent,
-                             int drbg_type);
-
-static int get_drbg_params(int type, unsigned int flags, const char **name,
-                           OSSL_PARAM params[3])
-{
-    OSSL_PARAM *p = params;
-
-    switch (type) {
-    case 0:
-        return 1;
-    default:
-        return 0;
-
-#define CTR(v)                                                              \
-    *name = "CTR-DRBG";                                                     \
-    *p++ = OSSL_PARAM_construct_utf8_string(OSSL_DRBG_PARAM_CIPHER, v, 0)
-
-    case NID_aes_128_ctr:
-        CTR(SN_aes_128_ctr);
-        break;
-    case NID_aes_192_ctr:
-        CTR(SN_aes_192_ctr);
-        break;
-    case NID_aes_256_ctr:
-        CTR(SN_aes_256_ctr);
-        break;
-
-#define DGST(v)                                                             \
-    *p++ = OSSL_PARAM_construct_utf8_string(OSSL_DRBG_PARAM_DIGEST, v, 0);  \
-    if ((flags & RAND_DRBG_FLAG_HMAC) == 0) {                               \
-        *name = "HASH-DRBG";                                                \
-    } else {                                                                \
-        *name = "HMAC-DRBG";                                                \
-        *p++ = OSSL_PARAM_construct_utf8_string(OSSL_DRBG_PARAM_MAC,        \
-                                                SN_hmac, 0);                \
-    }
-
-    case NID_sha1:
-        DGST(SN_sha1);
-        break;
-    case NID_sha224:
-        DGST(SN_sha224);
-        break;
-    case NID_sha256:
-        DGST(SN_sha256);
-        break;
-    case NID_sha384:
-        DGST(SN_sha384);
-        break;
-    case NID_sha512:
-        DGST(SN_sha512);
-        break;
-    case NID_sha512_224:
-        DGST(SN_sha512_224);
-        break;
-    case NID_sha512_256:
-        DGST(SN_sha512_256);
-        break;
-    case NID_sha3_224:
-        DGST(SN_sha3_224);
-        break;
-    case NID_sha3_256:
-        DGST(SN_sha3_256);
-        break;
-    case NID_sha3_384:
-        DGST(SN_sha3_384);
-        break;
-    case NID_sha3_512:
-        DGST(SN_sha3_512);
-    }
-    *p = OSSL_PARAM_construct_end();
-    return 1;
-}
-
-/*
- * Initialize the OPENSSL_CTX global DRBGs on first use.
- * Returns the allocated global data on success or NULL on failure.
- */
-static void *drbg_ossl_ctx_new(OPENSSL_CTX *libctx)
-{
-    DRBG_GLOBAL *dgbl = OPENSSL_zalloc(sizeof(*dgbl));
-
-    if (dgbl == NULL)
-        return NULL;
-
-#ifndef FIPS_MODULE
-    /*
-     * We need to ensure that base libcrypto thread handling has been
-     * initialised.
-     */
-     OPENSSL_init_crypto(0, NULL);
-#endif
-
-    dgbl->lock = CRYPTO_THREAD_lock_new();
-    if (dgbl->lock == NULL)
-        goto err0;
-
-    if (!CRYPTO_THREAD_init_local(&dgbl->private_drbg, NULL))
-        goto err1;
-
-    if (!CRYPTO_THREAD_init_local(&dgbl->public_drbg, NULL))
-        goto err2;
-
-    return dgbl;
-
- err2:
-    CRYPTO_THREAD_cleanup_local(&dgbl->private_drbg);
- err1:
-    CRYPTO_THREAD_lock_free(dgbl->lock);
- err0:
-    OPENSSL_free(dgbl);
-    return NULL;
-}
-
-static void drbg_ossl_ctx_free(void *vdgbl)
-{
-    DRBG_GLOBAL *dgbl = vdgbl;
-
-    if (dgbl == NULL)
-        return;
-
-    CRYPTO_THREAD_lock_free(dgbl->lock);
-    RAND_DRBG_free(dgbl->primary_drbg);
-    CRYPTO_THREAD_cleanup_local(&dgbl->private_drbg);
-    CRYPTO_THREAD_cleanup_local(&dgbl->public_drbg);
-
-    OPENSSL_free(dgbl);
-}
-
-static const OPENSSL_CTX_METHOD drbg_ossl_ctx_method = {
-    drbg_ossl_ctx_new,
-    drbg_ossl_ctx_free,
-};
-
-static DRBG_GLOBAL *drbg_get_global(OPENSSL_CTX *libctx)
-{
-    return openssl_ctx_get_data(libctx, OPENSSL_CTX_DRBG_INDEX,
-                                &drbg_ossl_ctx_method);
-}
-
-/*
- * Set the |drbg|'s callback data pointer for the entropy and nonce callbacks
- *
- * The ownership of the context data remains with the caller,
- * i.e., it is the caller's responsibility to keep it available as long
- * as it is need by the callbacks and free it after use.
- *
- * Setting the callback data is allowed only if the drbg has not been
- * initialized yet. Otherwise, the operation will fail.
- *
- * Returns 1 on success, 0 on failure.
- */
-int RAND_DRBG_set_callback_data(RAND_DRBG *drbg, void *data)
-{
-    if (EVP_RAND_state(drbg->rand) != EVP_RAND_STATE_UNINITIALISED
-            || drbg->parent != NULL)
-        return 0;
-
-    drbg->callback_data = data;
-    return 1;
-}
-
-/* Retrieve the callback data pointer */
-void *RAND_DRBG_get_callback_data(RAND_DRBG *drbg)
-{
-    return drbg->callback_data;
-}
-
-/*
- * Set/initialize |drbg| to be of type |type|, with optional |flags|.
- *
- * If |type| and |flags| are zero, use the defaults
- *
- * Returns 1 on success, 0 on failure.
- */
-int RAND_DRBG_set(RAND_DRBG *drbg, int type, unsigned int flags)
-{
-    OSSL_PARAM params[6], *p = params;
-    unsigned int reseed_interval;
-    time_t reseed_time_interval;
-    const char *name = NULL;
-    EVP_RAND *rand;
-    EVP_RAND_CTX *pctx;
-    int use_df;
-
-    RAND_DRBG_get_entropy_fn get_entropy = drbg->get_entropy;
-    RAND_DRBG_cleanup_entropy_fn cleanup_entropy = drbg->cleanup_entropy;
-    RAND_DRBG_get_nonce_fn get_nonce = drbg->get_nonce;
-    RAND_DRBG_cleanup_nonce_fn cleanup_nonce = drbg->cleanup_nonce;
-
-    if (type == 0 && flags == 0) {
-        type = rand_drbg_type[RAND_DRBG_TYPE_PRIMARY];
-        flags = rand_drbg_flags[RAND_DRBG_TYPE_PRIMARY];
-    }
-
-    if (drbg->parent == NULL) {
-        reseed_interval = primary_reseed_interval;
-        reseed_time_interval = primary_reseed_time_interval;
-    } else {
-        reseed_interval = secondary_reseed_interval;
-        reseed_time_interval = secondary_reseed_time_interval;
-    }
-    *p++ = OSSL_PARAM_construct_uint(OSSL_DRBG_PARAM_RESEED_REQUESTS,
-                                     &reseed_interval);
-    *p++ = OSSL_PARAM_construct_time_t(OSSL_DRBG_PARAM_RESEED_TIME_INTERVAL,
-                                       &reseed_time_interval);
-    use_df = (flags & RAND_DRBG_FLAG_CTR_NO_DF) == 0;
-    *p++ = OSSL_PARAM_construct_int(OSSL_DRBG_PARAM_USE_DF, &use_df);
-
-    if (!get_drbg_params(type, flags, &name, p)) {
-        RANDerr(0, RAND_R_UNSUPPORTED_DRBG_TYPE);
-        return 0;
-    }
-
-    rand = EVP_RAND_fetch(drbg->libctx, name, NULL);
-    if (rand == NULL) {
-        RANDerr(0, RAND_R_NO_DRBG_IMPLEMENTATION_SELECTED);
-        return 0;
-    }
-
-    EVP_RAND_CTX_free(drbg->rand);
-    drbg->rand = NULL;
-
-    drbg->flags = flags;
-    drbg->type = type;
-
-    pctx = drbg->parent != NULL ? drbg->parent->rand : NULL;
-    drbg->rand = EVP_RAND_CTX_new(rand, pctx);
-    EVP_RAND_free(rand);
-    if (drbg->rand == NULL) {
-        RANDerr(0, RAND_R_NO_DRBG_IMPLEMENTATION_SELECTED);
-        goto err;
-    }
-
-    if (!EVP_RAND_set_ctx_params(drbg->rand, params)) {
-        RANDerr(0, RAND_R_ERROR_INITIALISING_DRBG);