Raise an error on syscall failure in tls_retry_write_records
[openssl.git] / crypto / provider_core.c
index 4b5b0136080ba278162e95c55a9dd1ec52d1326b..297b281a39fc0f06e09998f06a5a09d6ada08ad1 100644 (file)
@@ -1,5 +1,5 @@
 /*
- * Copyright 2019-2020 The OpenSSL Project Authors. All Rights Reserved.
+ * Copyright 2019-2024 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
@@ -7,6 +7,7 @@
  * https://www.openssl.org/source/license.html
  */
 
+#include <assert.h>
 #include <openssl/core.h>
 #include <openssl/core_dispatch.h>
 #include <openssl/core_names.h>
 #include <openssl/params.h>
 #include <openssl/opensslv.h>
 #include "crypto/cryptlib.h"
-#include "crypto/evp.h" /* evp_method_store_flush */
+#ifndef FIPS_MODULE
+#include "crypto/decoder.h" /* ossl_decoder_store_cache_flush */
+#include "crypto/encoder.h" /* ossl_encoder_store_cache_flush */
+#include "crypto/store.h" /* ossl_store_loader_store_cache_flush */
+#endif
+#include "crypto/evp.h" /* evp_method_store_cache_flush */
+#include "crypto/rand.h"
 #include "internal/nelem.h"
 #include "internal/thread_once.h"
 #include "internal/provider.h"
 #include "internal/refcount.h"
+#include "internal/bio.h"
+#include "internal/core.h"
 #include "provider_local.h"
+#include "crypto/context.h"
 #ifndef FIPS_MODULE
 # include <openssl/self_test.h>
 #endif
 
+/*
+ * This file defines and uses a number of different structures:
+ *
+ * OSSL_PROVIDER (provider_st): Used to represent all information related to a
+ * single instance of a provider.
+ *
+ * provider_store_st: Holds information about the collection of providers that
+ * are available within the current library context (OSSL_LIB_CTX). It also
+ * holds configuration information about providers that could be loaded at some
+ * future point.
+ *
+ * OSSL_PROVIDER_CHILD_CB: An instance of this structure holds the callbacks
+ * that have been registered for a child library context and the associated
+ * provider that registered those callbacks.
+ *
+ * Where a child library context exists then it has its own instance of the
+ * provider store. Each provider that exists in the parent provider store, has
+ * an associated child provider in the child library context's provider store.
+ * As providers get activated or deactivated this needs to be mirrored in the
+ * associated child providers.
+ *
+ * LOCKING
+ * =======
+ *
+ * There are a number of different locks used in this file and it is important
+ * to understand how they should be used in order to avoid deadlocks.
+ *
+ * Fields within a structure can often be "write once" on creation, and then
+ * "read many". Creation of a structure is done by a single thread, and
+ * therefore no lock is required for the "write once/read many" fields. It is
+ * safe for multiple threads to read these fields without a lock, because they
+ * will never be changed.
+ *
+ * However some fields may be changed after a structure has been created and
+ * shared between multiple threads. Where this is the case a lock is required.
+ *
+ * The locks available are:
+ *
+ * The provider flag_lock: Used to control updates to the various provider
+ * "flags" (flag_initialized and flag_activated).
+ *
+ * The provider activatecnt_lock: Used to control updates to the provider
+ * activatecnt value.
+ *
+ * The provider optbits_lock: Used to control access to the provider's
+ * operation_bits and operation_bits_sz fields.
+ *
+ * The store default_path_lock: Used to control access to the provider store's
+ * default search path value (default_path)
+ *
+ * The store lock: Used to control the stack of provider's held within the
+ * provider store, as well as the stack of registered child provider callbacks.
+ *
+ * As a general rule-of-thumb it is best to:
+ *  - keep the scope of the code that is protected by a lock to the absolute
+ *    minimum possible;
+ *  - try to keep the scope of the lock to within a single function (i.e. avoid
+ *    making calls to other functions while holding a lock);
+ *  - try to only ever hold one lock at a time.
+ *
+ * Unfortunately, it is not always possible to stick to the above guidelines.
+ * Where they are not adhered to there is always a danger of inadvertently
+ * introducing the possibility of deadlock. The following rules MUST be adhered
+ * to in order to avoid that:
+ *  - Holding multiple locks at the same time is only allowed for the
+ *    provider store lock, the provider activatecnt_lock and the provider flag_lock.
+ *  - When holding multiple locks they must be acquired in the following order of
+ *    precedence:
+ *        1) provider store lock
+ *        2) provider flag_lock
+ *        3) provider activatecnt_lock
+ *  - When releasing locks they must be released in the reverse order to which
+ *    they were acquired
+ *  - No locks may be held when making an upcall. NOTE: Some common functions
+ *    can make upcalls as part of their normal operation. If you need to call
+ *    some other function while holding a lock make sure you know whether it
+ *    will make any upcalls or not. For example ossl_provider_up_ref() can call
+ *    ossl_provider_up_ref_parent() which can call the c_prov_up_ref() upcall.
+ *  - It is permissible to hold the store and flag locks when calling child
+ *    provider callbacks. No other locks may be held during such callbacks.
+ */
+
 static OSSL_PROVIDER *provider_new(const char *name,
-                                   OSSL_provider_init_fn *init_function);
+                                   OSSL_provider_init_fn *init_function,
+                                   STACK_OF(INFOPAIR) *parameters);
 
 /*-
  * Provider Object structure
  * =========================
  */
 
+#ifndef FIPS_MODULE
 typedef struct {
-    char *name;
-    char *value;
-} INFOPAIR;
-DEFINE_STACK_OF(INFOPAIR)
+    OSSL_PROVIDER *prov;
+    int (*create_cb)(const OSSL_CORE_HANDLE *provider, void *cbdata);
+    int (*remove_cb)(const OSSL_CORE_HANDLE *provider, void *cbdata);
+    int (*global_props_cb)(const char *props, void *cbdata);
+    void *cbdata;
+} OSSL_PROVIDER_CHILD_CB;
+DEFINE_STACK_OF(OSSL_PROVIDER_CHILD_CB)
+#endif
 
 struct provider_store_st;        /* Forward declaration */
 
 struct ossl_provider_st {
     /* Flag bits */
     unsigned int flag_initialized:1;
-    unsigned int flag_fallback:1; /* Can be used as fallback */
-    unsigned int flag_activated_as_fallback:1;
+    unsigned int flag_activated:1;
+
+    /* Getting and setting the flags require synchronization */
+    CRYPTO_RWLOCK *flag_lock;
 
     /* OpenSSL library side data */
     CRYPTO_REF_COUNT refcnt;
-    CRYPTO_RWLOCK *refcnt_lock;  /* For the ref counter */
+    CRYPTO_RWLOCK *activatecnt_lock; /* For the activatecnt counter */
+    int activatecnt;
     char *name;
     char *path;
     DSO *module;
     OSSL_provider_init_fn *init_function;
     STACK_OF(INFOPAIR) *parameters;
-    OPENSSL_CTX *libctx; /* The library context this instance is in */
+    OSSL_LIB_CTX *libctx; /* The library context this instance is in */
     struct provider_store_st *store; /* The store this instance belongs to */
 #ifndef FIPS_MODULE
     /*
@@ -74,6 +175,7 @@ struct ossl_provider_st {
     OSSL_FUNC_provider_get_capabilities_fn *get_capabilities;
     OSSL_FUNC_provider_self_test_fn *self_test;
     OSSL_FUNC_provider_query_operation_fn *query_operation;
+    OSSL_FUNC_provider_unquery_operation_fn *unquery_operation;
 
     /*
      * Cache of bit to indicate of query_operation() has been called on
@@ -81,9 +183,17 @@ struct ossl_provider_st {
      */
     unsigned char *operation_bits;
     size_t operation_bits_sz;
+    CRYPTO_RWLOCK *opbits_lock;
+
+#ifndef FIPS_MODULE
+    /* Whether this provider is the child of some other provider */
+    const OSSL_CORE_HANDLE *handle;
+    unsigned int ischild:1;
+#endif
 
     /* Provider side data */
     void *provctx;
+    const OSSL_DISPATCH *dispatch;
 };
 DEFINE_STACK_OF(OSSL_PROVIDER)
 
@@ -102,101 +212,190 @@ static int ossl_provider_cmp(const OSSL_PROVIDER * const *a,
  */
 
 struct provider_store_st {
+    OSSL_LIB_CTX *libctx;
     STACK_OF(OSSL_PROVIDER) *providers;
+    STACK_OF(OSSL_PROVIDER_CHILD_CB) *child_cbs;
+    CRYPTO_RWLOCK *default_path_lock;
     CRYPTO_RWLOCK *lock;
     char *default_path;
+    OSSL_PROVIDER_INFO *provinfo;
+    size_t numprovinfo;
+    size_t provinfosz;
     unsigned int use_fallbacks:1;
+    unsigned int freeing:1;
 };
 
 /*
- * provider_deactivate_free() is a wrapper around ossl_provider_free()
- * that also makes sure that activated fallback providers are deactivated.
- * This is simply done by freeing them an extra time, to compensate for the
- * refcount that provider_activate_fallbacks() gives them.
+ * provider_deactivate_free() is a wrapper around ossl_provider_deactivate()
+ * and ossl_provider_free(), called as needed.
  * Since this is only called when the provider store is being emptied, we
  * don't need to care about any lock.
  */
 static void provider_deactivate_free(OSSL_PROVIDER *prov)
 {
-    int extra_free = (prov->flag_initialized
-                      && prov->flag_activated_as_fallback);
-
-    if (extra_free)
-        ossl_provider_free(prov);
+    if (prov->flag_activated)
+        ossl_provider_deactivate(prov, 1);
     ossl_provider_free(prov);
 }
 
-static void provider_store_free(void *vstore)
+#ifndef FIPS_MODULE
+static void ossl_provider_child_cb_free(OSSL_PROVIDER_CHILD_CB *cb)
+{
+    OPENSSL_free(cb);
+}
+#endif
+
+static void infopair_free(INFOPAIR *pair)
+{
+    OPENSSL_free(pair->name);
+    OPENSSL_free(pair->value);
+    OPENSSL_free(pair);
+}
+
+static INFOPAIR *infopair_copy(const INFOPAIR *src)
+{
+    INFOPAIR *dest = OPENSSL_zalloc(sizeof(*dest));
+
+    if (dest == NULL)
+        return NULL;
+    if (src->name != NULL) {
+        dest->name = OPENSSL_strdup(src->name);
+        if (dest->name == NULL)
+            goto err;
+    }
+    if (src->value != NULL) {
+        dest->value = OPENSSL_strdup(src->value);
+        if (dest->value == NULL)
+            goto err;
+    }
+    return dest;
+ err:
+    OPENSSL_free(dest->name);
+    OPENSSL_free(dest);
+    return NULL;
+}
+
+void ossl_provider_info_clear(OSSL_PROVIDER_INFO *info)
+{
+    OPENSSL_free(info->name);
+    OPENSSL_free(info->path);
+    sk_INFOPAIR_pop_free(info->parameters, infopair_free);
+}
+
+void ossl_provider_store_free(void *vstore)
 {
     struct provider_store_st *store = vstore;
+    size_t i;
 
     if (store == NULL)
         return;
+    store->freeing = 1;
     OPENSSL_free(store->default_path);
     sk_OSSL_PROVIDER_pop_free(store->providers, provider_deactivate_free);
+#ifndef FIPS_MODULE
+    sk_OSSL_PROVIDER_CHILD_CB_pop_free(store->child_cbs,
+                                       ossl_provider_child_cb_free);
+#endif
+    CRYPTO_THREAD_lock_free(store->default_path_lock);
     CRYPTO_THREAD_lock_free(store->lock);
+    for (i = 0; i < store->numprovinfo; i++)
+        ossl_provider_info_clear(&store->provinfo[i]);
+    OPENSSL_free(store->provinfo);
     OPENSSL_free(store);
 }
 
-static void *provider_store_new(OPENSSL_CTX *ctx)
+void *ossl_provider_store_new(OSSL_LIB_CTX *ctx)
 {
     struct provider_store_st *store = OPENSSL_zalloc(sizeof(*store));
-    const struct predefined_providers_st *p = NULL;
 
     if (store == NULL
         || (store->providers = sk_OSSL_PROVIDER_new(ossl_provider_cmp)) == NULL
+        || (store->default_path_lock = CRYPTO_THREAD_lock_new()) == NULL
+#ifndef FIPS_MODULE
+        || (store->child_cbs = sk_OSSL_PROVIDER_CHILD_CB_new_null()) == NULL
+#endif
         || (store->lock = CRYPTO_THREAD_lock_new()) == NULL) {
-        provider_store_free(store);
+        ossl_provider_store_free(store);
         return NULL;
     }
+    store->libctx = ctx;
     store->use_fallbacks = 1;
 
-    for (p = predefined_providers; p->name != NULL; p++) {
-        OSSL_PROVIDER *prov = NULL;
-
-        /*
-         * We use the internal constructor directly here,
-         * otherwise we get a call loop
-         */
-        prov = provider_new(p->name, p->init);
-
-        if (prov == NULL
-            || sk_OSSL_PROVIDER_push(store->providers, prov) == 0) {
-            ossl_provider_free(prov);
-            provider_store_free(store);
-            CRYPTOerr(CRYPTO_F_PROVIDER_STORE_NEW, ERR_R_INTERNAL_ERROR);
-            return NULL;
-        }
-        prov->libctx = ctx;
-        prov->store = store;
-#ifndef FIPS_MODULE
-        prov->error_lib = ERR_get_next_error_library();
-#endif
-        if(p->is_fallback)
-            ossl_provider_set_fallback(prov);
-    }
-
     return store;
 }
 
-static const OPENSSL_CTX_METHOD provider_store_method = {
-    provider_store_new,
-    provider_store_free,
-};
-
-static struct provider_store_st *get_provider_store(OPENSSL_CTX *libctx)
+static struct provider_store_st *get_provider_store(OSSL_LIB_CTX *libctx)
 {
     struct provider_store_st *store = NULL;
 
-    store = openssl_ctx_get_data(libctx, OPENSSL_CTX_PROVIDER_STORE_INDEX,
-                                 &provider_store_method);
+    store = ossl_lib_ctx_get_data(libctx, OSSL_LIB_CTX_PROVIDER_STORE_INDEX);
     if (store == NULL)
-        CRYPTOerr(CRYPTO_F_GET_PROVIDER_STORE, ERR_R_INTERNAL_ERROR);
+        ERR_raise(ERR_LIB_CRYPTO, ERR_R_INTERNAL_ERROR);
     return store;
 }
 
-OSSL_PROVIDER *ossl_provider_find(OPENSSL_CTX *libctx, const char *name,
-                                  int noconfig)
+int ossl_provider_disable_fallback_loading(OSSL_LIB_CTX *libctx)
+{
+    struct provider_store_st *store;
+
+    if ((store = get_provider_store(libctx)) != NULL) {
+        if (!CRYPTO_THREAD_write_lock(store->lock))
+            return 0;
+        store->use_fallbacks = 0;
+        CRYPTO_THREAD_unlock(store->lock);
+        return 1;
+    }
+    return 0;
+}
+
+#define BUILTINS_BLOCK_SIZE     10
+
+int ossl_provider_info_add_to_store(OSSL_LIB_CTX *libctx,
+                                    OSSL_PROVIDER_INFO *entry)
+{
+    struct provider_store_st *store = get_provider_store(libctx);
+    int ret = 0;
+
+    if (entry->name == NULL) {
+        ERR_raise(ERR_LIB_CRYPTO, ERR_R_PASSED_NULL_PARAMETER);
+        return 0;
+    }
+
+    if (store == NULL) {
+        ERR_raise(ERR_LIB_CRYPTO, ERR_R_INTERNAL_ERROR);
+        return 0;
+    }
+
+    if (!CRYPTO_THREAD_write_lock(store->lock))
+        return 0;
+    if (store->provinfosz == 0) {
+        store->provinfo = OPENSSL_zalloc(sizeof(*store->provinfo)
+                                         * BUILTINS_BLOCK_SIZE);
+        if (store->provinfo == NULL)
+            goto err;
+        store->provinfosz = BUILTINS_BLOCK_SIZE;
+    } else if (store->numprovinfo == store->provinfosz) {
+        OSSL_PROVIDER_INFO *tmpbuiltins;
+        size_t newsz = store->provinfosz + BUILTINS_BLOCK_SIZE;
+
+        tmpbuiltins = OPENSSL_realloc(store->provinfo,
+                                      sizeof(*store->provinfo) * newsz);
+        if (tmpbuiltins == NULL)
+            goto err;
+        store->provinfo = tmpbuiltins;
+        store->provinfosz = newsz;
+    }
+    store->provinfo[store->numprovinfo] = *entry;
+    store->numprovinfo++;
+
+    ret = 1;
+ err:
+    CRYPTO_THREAD_unlock(store->lock);
+    return ret;
+}
+
+OSSL_PROVIDER *ossl_provider_find(OSSL_LIB_CTX *libctx, const char *name,
+                                  ossl_unused int noconfig)
 {
     struct provider_store_st *store = NULL;
     OSSL_PROVIDER *prov = NULL;
@@ -205,22 +404,26 @@ OSSL_PROVIDER *ossl_provider_find(OPENSSL_CTX *libctx, const char *name,
         OSSL_PROVIDER tmpl = { 0, };
         int i;
 
-#ifndef FIPS_MODULE
+#if !defined(FIPS_MODULE) && !defined(OPENSSL_NO_AUTOLOAD_CONFIG)
         /*
          * Make sure any providers are loaded from config before we try to find
          * them.
          */
-        if (!noconfig)
-            OPENSSL_init_crypto(OPENSSL_INIT_LOAD_CONFIG, NULL);
+        if (!noconfig) {
+            if (ossl_lib_ctx_is_default(libctx))
+                OPENSSL_init_crypto(OPENSSL_INIT_LOAD_CONFIG, NULL);
+        }
 #endif
 
         tmpl.name = (char *)name;
-        CRYPTO_THREAD_write_lock(store->lock);
-        if ((i = sk_OSSL_PROVIDER_find(store->providers, &tmpl)) == -1
-            || (prov = sk_OSSL_PROVIDER_value(store->providers, i)) == NULL
-            || !ossl_provider_up_ref(prov))
-            prov = NULL;
+        if (!CRYPTO_THREAD_write_lock(store->lock))
+            return NULL;
+        sk_OSSL_PROVIDER_sort(store->providers);
+        if ((i = sk_OSSL_PROVIDER_find(store->providers, &tmpl)) != -1)
+            prov = sk_OSSL_PROVIDER_value(store->providers, i);
         CRYPTO_THREAD_unlock(store->lock);
+        if (prov != NULL && !ossl_provider_up_ref(prov))
+            prov = NULL;
     }
 
     return prov;
@@ -232,22 +435,39 @@ OSSL_PROVIDER *ossl_provider_find(OPENSSL_CTX *libctx, const char *name,
  */
 
 static OSSL_PROVIDER *provider_new(const char *name,
-                                   OSSL_provider_init_fn *init_function)
+                                   OSSL_provider_init_fn *init_function,
+                                   STACK_OF(INFOPAIR) *parameters)
 {
     OSSL_PROVIDER *prov = NULL;
 
-    if ((prov = OPENSSL_zalloc(sizeof(*prov))) == NULL
-#ifndef HAVE_ATOMICS
-        || (prov->refcnt_lock = CRYPTO_THREAD_lock_new()) == NULL
-#endif
-        || !ossl_provider_up_ref(prov) /* +1 One reference to be returned */
-        || (prov->name = OPENSSL_strdup(name)) == NULL) {
+    if ((prov = OPENSSL_zalloc(sizeof(*prov))) == NULL)
+        return NULL;
+    if (!CRYPTO_NEW_REF(&prov->refcnt, 1)) {
+        OPENSSL_free(prov);
+        return NULL;
+    }
+    if ((prov->activatecnt_lock = CRYPTO_THREAD_lock_new()) == NULL) {
+        ossl_provider_free(prov);
+        ERR_raise(ERR_LIB_CRYPTO, ERR_R_CRYPTO_LIB);
+        return NULL;
+    }
+
+    if ((prov->opbits_lock = CRYPTO_THREAD_lock_new()) == NULL
+        || (prov->flag_lock = CRYPTO_THREAD_lock_new()) == NULL
+        || (prov->parameters = sk_INFOPAIR_deep_copy(parameters,
+                                                     infopair_copy,
+                                                     infopair_free)) == NULL) {
+        ossl_provider_free(prov);
+        ERR_raise(ERR_LIB_CRYPTO, ERR_R_CRYPTO_LIB);
+        return NULL;
+    }
+    if ((prov->name = OPENSSL_strdup(name)) == NULL) {
         ossl_provider_free(prov);
-        CRYPTOerr(CRYPTO_F_PROVIDER_NEW, ERR_R_MALLOC_FAILURE);
         return NULL;
     }
 
     prov->init_function = init_function;
+
     return prov;
 }
 
@@ -255,66 +475,229 @@ int ossl_provider_up_ref(OSSL_PROVIDER *prov)
 {
     int ref = 0;
 
-    if (CRYPTO_UP_REF(&prov->refcnt, &ref, prov->refcnt_lock) <= 0)
+    if (CRYPTO_UP_REF(&prov->refcnt, &ref) <= 0)
         return 0;
+
+#ifndef FIPS_MODULE
+    if (prov->ischild) {
+        if (!ossl_provider_up_ref_parent(prov, 0)) {
+            ossl_provider_free(prov);
+            return 0;
+        }
+    }
+#endif
+
     return ref;
 }
 
-OSSL_PROVIDER *ossl_provider_new(OPENSSL_CTX *libctx, const char *name,
+#ifndef FIPS_MODULE
+static int provider_up_ref_intern(OSSL_PROVIDER *prov, int activate)
+{
+    if (activate)
+        return ossl_provider_activate(prov, 1, 0);
+
+    return ossl_provider_up_ref(prov);
+}
+
+static int provider_free_intern(OSSL_PROVIDER *prov, int deactivate)
+{
+    if (deactivate)
+        return ossl_provider_deactivate(prov, 1);
+
+    ossl_provider_free(prov);
+    return 1;
+}
+#endif
+
+/*
+ * We assume that the requested provider does not already exist in the store.
+ * The caller should check. If it does exist then adding it to the store later
+ * will fail.
+ */
+OSSL_PROVIDER *ossl_provider_new(OSSL_LIB_CTX *libctx, const char *name,
                                  OSSL_provider_init_fn *init_function,
-                                 int noconfig)
+                                 OSSL_PARAM *params, int noconfig)
 {
     struct provider_store_st *store = NULL;
+    OSSL_PROVIDER_INFO template;
     OSSL_PROVIDER *prov = NULL;
 
     if ((store = get_provider_store(libctx)) == NULL)
         return NULL;
 
-    if ((prov = ossl_provider_find(libctx, name,
-                                   noconfig)) != NULL) { /* refcount +1 */
-        ossl_provider_free(prov); /* refcount -1 */
-        ERR_raise_data(ERR_LIB_CRYPTO, CRYPTO_R_PROVIDER_ALREADY_EXISTS, NULL,
-                       "name=%s", name);
-        return NULL;
+    memset(&template, 0, sizeof(template));
+    if (init_function == NULL) {
+        const OSSL_PROVIDER_INFO *p;
+        size_t i;
+
+        /* Check if this is a predefined builtin provider */
+        for (p = ossl_predefined_providers; p->name != NULL; p++) {
+            if (strcmp(p->name, name) == 0) {
+                template = *p;
+                break;
+            }
+        }
+        if (p->name == NULL) {
+            /* Check if this is a user added provider */
+            if (!CRYPTO_THREAD_read_lock(store->lock))
+                return NULL;
+            for (i = 0, p = store->provinfo; i < store->numprovinfo; p++, i++) {
+                if (strcmp(p->name, name) == 0) {
+                    template = *p;
+                    break;
+                }
+            }
+            CRYPTO_THREAD_unlock(store->lock);
+        }
+    } else {
+        template.init = init_function;
+    }
+
+    if (params != NULL) {
+        int i;
+
+        template.parameters = sk_INFOPAIR_new_null();
+        if (template.parameters == NULL)
+            return NULL;
+
+        for (i = 0; params[i].key != NULL; i++) {
+            if (params[i].data_type != OSSL_PARAM_UTF8_STRING)
+                continue;
+            if (ossl_provider_info_add_parameter(&template, params[i].key,
+                                                 (char *)params[i].data) <= 0) {
+                sk_INFOPAIR_pop_free(template.parameters, infopair_free);
+                return NULL;
+            }
+        }
     }
 
     /* provider_new() generates an error, so no need here */
-    if ((prov = provider_new(name, init_function)) == NULL)
+    prov = provider_new(name, template.init, template.parameters);
+
+    if (params != NULL) /* We copied the parameters, let's free them */
+        sk_INFOPAIR_pop_free(template.parameters, infopair_free);
+
+    if (prov == NULL)
         return NULL;
 
-    CRYPTO_THREAD_write_lock(store->lock);
-    if (!ossl_provider_up_ref(prov)) { /* +1 One reference for the store */
-        ossl_provider_free(prov); /* -1 Reference that was to be returned */
-        prov = NULL;
-    } else if (sk_OSSL_PROVIDER_push(store->providers, prov) == 0) {
-        ossl_provider_free(prov); /* -1 Store reference */
-        ossl_provider_free(prov); /* -1 Reference that was to be returned */
-        prov = NULL;
-    } else {
-        prov->libctx = libctx;
-        prov->store = store;
-#ifndef FIPS_MODULE
-        prov->error_lib = ERR_get_next_error_library();
-#endif
+    if (!ossl_provider_set_module_path(prov, template.path)) {
+        ossl_provider_free(prov);
+        return NULL;
     }
-    CRYPTO_THREAD_unlock(store->lock);
 
-    if (prov == NULL)
-        CRYPTOerr(CRYPTO_F_OSSL_PROVIDER_NEW, ERR_R_MALLOC_FAILURE);
+    prov->libctx = libctx;
+#ifndef FIPS_MODULE
+    prov->error_lib = ERR_get_next_error_library();
+#endif
 
     /*
      * At this point, the provider is only partially "loaded".  To be
-     * fully "loaded", ossl_provider_activate() must also be called.
+     * fully "loaded", ossl_provider_activate() must also be called and it must
+     * then be added to the provider store.
      */
 
     return prov;
 }
 
-static void free_infopair(INFOPAIR *pair)
+/* Assumes that the store lock is held */
+static int create_provider_children(OSSL_PROVIDER *prov)
 {
-    OPENSSL_free(pair->name);
-    OPENSSL_free(pair->value);
-    OPENSSL_free(pair);
+    int ret = 1;
+#ifndef FIPS_MODULE
+    struct provider_store_st *store = prov->store;
+    OSSL_PROVIDER_CHILD_CB *child_cb;
+    int i, max;
+
+    max = sk_OSSL_PROVIDER_CHILD_CB_num(store->child_cbs);
+    for (i = 0; i < max; i++) {
+        /*
+         * This is newly activated (activatecnt == 1), so we need to
+         * create child providers as necessary.
+         */
+        child_cb = sk_OSSL_PROVIDER_CHILD_CB_value(store->child_cbs, i);
+        ret &= child_cb->create_cb((OSSL_CORE_HANDLE *)prov, child_cb->cbdata);
+    }
+#endif
+
+    return ret;
+}
+
+int ossl_provider_add_to_store(OSSL_PROVIDER *prov, OSSL_PROVIDER **actualprov,
+                               int retain_fallbacks)
+{
+    struct provider_store_st *store;
+    int idx;
+    OSSL_PROVIDER tmpl = { 0, };
+    OSSL_PROVIDER *actualtmp = NULL;
+
+    if (actualprov != NULL)
+        *actualprov = NULL;
+
+    if ((store = get_provider_store(prov->libctx)) == NULL)
+        return 0;
+
+    if (!CRYPTO_THREAD_write_lock(store->lock))
+        return 0;
+
+    tmpl.name = (char *)prov->name;
+    idx = sk_OSSL_PROVIDER_find(store->providers, &tmpl);
+    if (idx == -1)
+        actualtmp = prov;
+    else
+        actualtmp = sk_OSSL_PROVIDER_value(store->providers, idx);
+
+    if (idx == -1) {
+        if (sk_OSSL_PROVIDER_push(store->providers, prov) == 0)
+            goto err;
+        prov->store = store;
+        if (!create_provider_children(prov)) {
+            sk_OSSL_PROVIDER_delete_ptr(store->providers, prov);
+            goto err;
+        }
+        if (!retain_fallbacks)
+            store->use_fallbacks = 0;
+    }
+
+    CRYPTO_THREAD_unlock(store->lock);
+
+    if (actualprov != NULL) {
+        if (!ossl_provider_up_ref(actualtmp)) {
+            ERR_raise(ERR_LIB_CRYPTO, ERR_R_CRYPTO_LIB);
+            actualtmp = NULL;
+            return 0;
+        }
+        *actualprov = actualtmp;
+    }
+
+    if (idx >= 0) {
+        /*
+         * The provider is already in the store. Probably two threads
+         * independently initialised their own provider objects with the same
+         * name and raced to put them in the store. This thread lost. We
+         * deactivate the one we just created and use the one that already
+         * exists instead.
+         * If we get here then we know we did not create provider children
+         * above, so we inform ossl_provider_deactivate not to attempt to remove
+         * any.
+         */
+        ossl_provider_deactivate(prov, 0);
+        ossl_provider_free(prov);
+    }
+#ifndef FIPS_MODULE
+    else {
+        /*
+         * This can be done outside the lock. We tolerate other threads getting
+         * the wrong result briefly when creating OSSL_DECODER_CTXs.
+         */
+        ossl_decoder_cache_flush(prov->libctx);
+    }
+#endif
+
+    return 1;
+
+ err:
+    CRYPTO_THREAD_unlock(store->lock);
+    return 0;
 }
 
 void ossl_provider_free(OSSL_PROVIDER *prov)
@@ -322,52 +705,57 @@ void ossl_provider_free(OSSL_PROVIDER *prov)
     if (prov != NULL) {
         int ref = 0;
 
-        CRYPTO_DOWN_REF(&prov->refcnt, &ref, prov->refcnt_lock);
+        CRYPTO_DOWN_REF(&prov->refcnt, &ref);
 
         /*
-         * When the refcount drops below two, the store is the only
-         * possible reference, or it has already been taken away from
-         * the store (this may happen if a provider was activated
-         * because it's a fallback, but isn't currently used)
-         * When that happens, the provider is inactivated.
+         * When the refcount drops to zero, we clean up the provider.
+         * Note that this also does teardown, which may seem late,
+         * considering that init happens on first activation.  However,
+         * there may be other structures hanging on to the provider after
+         * the last deactivation and may therefore need full access to the
+         * provider's services.  Therefore, we deinit late.
          */
-        if (ref < 2 && prov->flag_initialized) {
-#ifndef FIPS_MODULE
-            ossl_init_thread_deregister(prov);
-#endif
-            if (prov->teardown != NULL)
-                prov->teardown(prov->provctx);
+        if (ref == 0) {
+            if (prov->flag_initialized) {
+                ossl_provider_teardown(prov);
 #ifndef OPENSSL_NO_ERR
 # ifndef FIPS_MODULE
-            if (prov->error_strings != NULL) {
-                ERR_unload_strings(prov->error_lib, prov->error_strings);
-                OPENSSL_free(prov->error_strings);
-                prov->error_strings = NULL;
-            }
+                if (prov->error_strings != NULL) {
+                    ERR_unload_strings(prov->error_lib, prov->error_strings);
+                    OPENSSL_free(prov->error_strings);
+                    prov->error_strings = NULL;
+                }
 # endif
 #endif
-            OPENSSL_free(prov->operation_bits);
-            prov->operation_bits = NULL;
-            prov->operation_bits_sz = 0;
-            prov->flag_initialized = 0;
-        }
+                OPENSSL_free(prov->operation_bits);
+                prov->operation_bits = NULL;
+                prov->operation_bits_sz = 0;
+                prov->flag_initialized = 0;
+            }
 
-        /*
-         * When the refcount drops to zero, it has been taken out of
-         * the store.  All we have to do here is clean it out.
-         */
-        if (ref == 0) {
 #ifndef FIPS_MODULE
+            /*
+             * We deregister thread handling whether or not the provider was
+             * initialized. If init was attempted but was not successful then
+             * the provider may still have registered a thread handler.
+             */
+            ossl_init_thread_deregister(prov);
             DSO_free(prov->module);
 #endif
             OPENSSL_free(prov->name);
             OPENSSL_free(prov->path);
-            sk_INFOPAIR_pop_free(prov->parameters, free_infopair);
-#ifndef HAVE_ATOMICS
-            CRYPTO_THREAD_lock_free(prov->refcnt_lock);
-#endif
+            sk_INFOPAIR_pop_free(prov->parameters, infopair_free);
+            CRYPTO_THREAD_lock_free(prov->opbits_lock);
+            CRYPTO_THREAD_lock_free(prov->flag_lock);
+            CRYPTO_THREAD_lock_free(prov->activatecnt_lock);
+            CRYPTO_FREE_REF(&prov->refcnt);
             OPENSSL_free(prov);
         }
+#ifndef FIPS_MODULE
+        else if (prov->ischild) {
+            ossl_provider_free_parent(prov, 0);
+        }
+#endif
     }
 }
 
@@ -375,36 +763,55 @@ void ossl_provider_free(OSSL_PROVIDER *prov)
 int ossl_provider_set_module_path(OSSL_PROVIDER *prov, const char *module_path)
 {
     OPENSSL_free(prov->path);
+    prov->path = NULL;
     if (module_path == NULL)
         return 1;
     if ((prov->path = OPENSSL_strdup(module_path)) != NULL)
         return 1;
-    CRYPTOerr(CRYPTO_F_OSSL_PROVIDER_SET_MODULE_PATH, ERR_R_MALLOC_FAILURE);
     return 0;
 }
 
-int ossl_provider_add_parameter(OSSL_PROVIDER *prov,
-                                const char *name, const char *value)
+static int infopair_add(STACK_OF(INFOPAIR) **infopairsk, const char *name,
+                        const char *value)
 {
     INFOPAIR *pair = NULL;
 
-    if ((pair = OPENSSL_zalloc(sizeof(*pair))) != NULL
-        && (prov->parameters != NULL
-            || (prov->parameters = sk_INFOPAIR_new_null()) != NULL)
-        && (pair->name = OPENSSL_strdup(name)) != NULL
-        && (pair->value = OPENSSL_strdup(value)) != NULL
-        && sk_INFOPAIR_push(prov->parameters, pair) > 0)
-        return 1;
+    if ((pair = OPENSSL_zalloc(sizeof(*pair))) == NULL
+        || (pair->name = OPENSSL_strdup(name)) == NULL
+        || (pair->value = OPENSSL_strdup(value)) == NULL)
+        goto err;
 
+    if ((*infopairsk == NULL
+         && (*infopairsk = sk_INFOPAIR_new_null()) == NULL)
+        || sk_INFOPAIR_push(*infopairsk, pair) <= 0) {
+        ERR_raise(ERR_LIB_CRYPTO, ERR_R_CRYPTO_LIB);
+        goto err;
+    }
+
+    return 1;
+
+ err:
     if (pair != NULL) {
         OPENSSL_free(pair->name);
         OPENSSL_free(pair->value);
         OPENSSL_free(pair);
     }
-    CRYPTOerr(CRYPTO_F_OSSL_PROVIDER_ADD_PARAMETER, ERR_R_MALLOC_FAILURE);
     return 0;
 }
 
+int ossl_provider_add_parameter(OSSL_PROVIDER *prov,
+                                const char *name, const char *value)
+{
+    return infopair_add(&prov->parameters, name, value);
+}
+
+int ossl_provider_info_add_parameter(OSSL_PROVIDER_INFO *provinfo,
+                                     const char *name,
+                                     const char *value)
+{
+    return infopair_add(&provinfo->parameters, name, value);
+}
+
 /*
  * Provider activation.
  *
@@ -419,35 +826,47 @@ int ossl_provider_add_parameter(OSSL_PROVIDER *prov,
  */
 static const OSSL_DISPATCH *core_dispatch; /* Define further down */
 
-int OSSL_PROVIDER_set_default_search_path(OPENSSL_CTX *libctx, const char *path)
+int OSSL_PROVIDER_set_default_search_path(OSSL_LIB_CTX *libctx,
+                                          const char *path)
 {
     struct provider_store_st *store;
     char *p = NULL;
 
     if (path != NULL) {
         p = OPENSSL_strdup(path);
-        if (p == NULL) {
-            CRYPTOerr(0, ERR_R_MALLOC_FAILURE);
+        if (p == NULL)
             return 0;
-        }
     }
     if ((store = get_provider_store(libctx)) != NULL
-            && CRYPTO_THREAD_write_lock(store->lock)) {
+            && CRYPTO_THREAD_write_lock(store->default_path_lock)) {
         OPENSSL_free(store->default_path);
         store->default_path = p;
-        CRYPTO_THREAD_unlock(store->lock);
+        CRYPTO_THREAD_unlock(store->default_path_lock);
         return 1;
     }
     OPENSSL_free(p);
     return 0;
 }
 
+const char *OSSL_PROVIDER_get0_default_search_path(OSSL_LIB_CTX *libctx)
+{
+    struct provider_store_st *store;
+    char *path = NULL;
+
+    if ((store = get_provider_store(libctx)) != NULL
+            && CRYPTO_THREAD_read_lock(store->default_path_lock)) {
+        path = store->default_path;
+        CRYPTO_THREAD_unlock(store->default_path_lock);
+    }
+    return path;
+}
+
 /*
  * Internal version that doesn't affect the store flags, and thereby avoid
  * locking.  Direct callers must remember to set the store flags when
  * appropriate.
  */
-static int provider_activate(OSSL_PROVIDER *prov)
+static int provider_init(OSSL_PROVIDER *prov)
 {
     const OSSL_DISPATCH *provider_dispatch = NULL;
     void *tmp_provctx = NULL;    /* safety measure */
@@ -456,9 +875,12 @@ static int provider_activate(OSSL_PROVIDER *prov)
     OSSL_FUNC_provider_get_reason_strings_fn *p_get_reason_strings = NULL;
 # endif
 #endif
+    int ok = 0;
 
-    if (prov->flag_initialized)
-        return 1;
+    if (!ossl_assert(!prov->flag_initialized)) {
+        ERR_raise(ERR_LIB_CRYPTO, ERR_R_INTERNAL_ERROR);
+        goto end;
+    }
 
     /*
      * If the init function isn't set, it indicates that this provider is
@@ -466,24 +888,34 @@ static int provider_activate(OSSL_PROVIDER *prov)
      */
     if (prov->init_function == NULL) {
 #ifdef FIPS_MODULE
-        return 0;
+        goto end;
 #else
         if (prov->module == NULL) {
             char *allocated_path = NULL;
             const char *module_path = NULL;
             char *merged_path = NULL;
             const char *load_dir = NULL;
+            char *allocated_load_dir = NULL;
             struct provider_store_st *store;
 
             if ((prov->module = DSO_new()) == NULL) {
                 /* DSO_new() generates an error already */
-                return 0;
+                goto end;
             }
 
             if ((store = get_provider_store(prov->libctx)) == NULL
-                    || !CRYPTO_THREAD_read_lock(store->lock))
-                return 0;
-            load_dir = store->default_path;
+                    || !CRYPTO_THREAD_read_lock(store->default_path_lock))
+                goto end;
+
+            if (store->default_path != NULL) {
+                allocated_load_dir = OPENSSL_strdup(store->default_path);
+                CRYPTO_THREAD_unlock(store->default_path_lock);
+                if (allocated_load_dir == NULL)
+                    goto end;
+                load_dir = allocated_load_dir;
+            } else {
+                CRYPTO_THREAD_unlock(store->default_path_lock);
+            }
 
             if (load_dir == NULL) {
                 load_dir = ossl_safe_getenv("OPENSSL_MODULES");
@@ -500,7 +932,6 @@ static int provider_activate(OSSL_PROVIDER *prov)
                     DSO_convert_filename(prov->module, prov->name);
             if (module_path != NULL)
                 merged_path = DSO_merge(prov->module, module_path, load_dir);
-            CRYPTO_THREAD_unlock(store->lock);
 
             if (merged_path == NULL
                 || (DSO_load(prov->module, merged_path, NULL, 0)) == NULL) {
@@ -510,62 +941,78 @@ static int provider_activate(OSSL_PROVIDER *prov)
 
             OPENSSL_free(merged_path);
             OPENSSL_free(allocated_path);
+            OPENSSL_free(allocated_load_dir);
         }
 
-        if (prov->module != NULL)
-            prov->init_function = (OSSL_provider_init_fn *)
-                DSO_bind_func(prov->module, "OSSL_provider_init");
+        if (prov->module == NULL) {
+            /* DSO has already recorded errors, this is just a tracepoint */
+            ERR_raise_data(ERR_LIB_CRYPTO, ERR_R_DSO_LIB,
+                           "name=%s", prov->name);
+            goto end;
+        }
+
+        prov->init_function = (OSSL_provider_init_fn *)
+            DSO_bind_func(prov->module, "OSSL_provider_init");
 #endif
     }
 
-    /* Call the initialise function for the provider. */
-    if (prov->init_function == NULL
-        || !prov->init_function((OSSL_CORE_HANDLE *)prov, core_dispatch,
-                                &provider_dispatch, &tmp_provctx)) {
-        ERR_raise_data(ERR_LIB_CRYPTO, ERR_R_INIT_FAIL, NULL,
+    /* Check for and call the initialise function for the provider. */
+    if (prov->init_function == NULL) {
+        ERR_raise_data(ERR_LIB_CRYPTO, ERR_R_UNSUPPORTED,
+                       "name=%s, provider has no provider init function",
+                       prov->name);
+        goto end;
+    }
+
+    if (!prov->init_function((OSSL_CORE_HANDLE *)prov, core_dispatch,
+                             &provider_dispatch, &tmp_provctx)) {
+        ERR_raise_data(ERR_LIB_CRYPTO, ERR_R_INIT_FAIL,
                        "name=%s", prov->name);
-#ifndef FIPS_MODULE
-        DSO_free(prov->module);
-        prov->module = NULL;
-#endif
-        return 0;
+        goto end;
     }
     prov->provctx = tmp_provctx;
-
-    for (; provider_dispatch->function_id != 0; provider_dispatch++) {
-        switch (provider_dispatch->function_id) {
-        case OSSL_FUNC_PROVIDER_TEARDOWN:
-            prov->teardown =
-                OSSL_FUNC_provider_teardown(provider_dispatch);
-            break;
-        case OSSL_FUNC_PROVIDER_GETTABLE_PARAMS:
-            prov->gettable_params =
-                OSSL_FUNC_provider_gettable_params(provider_dispatch);
-            break;
-        case OSSL_FUNC_PROVIDER_GET_PARAMS:
-            prov->get_params =
-                OSSL_FUNC_provider_get_params(provider_dispatch);
-            break;
-        case OSSL_FUNC_PROVIDER_SELF_TEST:
-            prov->self_test =
-                OSSL_FUNC_provider_self_test(provider_dispatch);
-            break;
-        case OSSL_FUNC_PROVIDER_GET_CAPABILITIES:
-            prov->get_capabilities =
-                OSSL_FUNC_provider_get_capabilities(provider_dispatch);
-            break;
-        case OSSL_FUNC_PROVIDER_QUERY_OPERATION:
-            prov->query_operation =
-                OSSL_FUNC_provider_query_operation(provider_dispatch);
-            break;
+    prov->dispatch = provider_dispatch;
+
+    if (provider_dispatch != NULL) {
+        for (; provider_dispatch->function_id != 0; provider_dispatch++) {
+            switch (provider_dispatch->function_id) {
+            case OSSL_FUNC_PROVIDER_TEARDOWN:
+                prov->teardown =
+                    OSSL_FUNC_provider_teardown(provider_dispatch);
+                break;
+            case OSSL_FUNC_PROVIDER_GETTABLE_PARAMS:
+                prov->gettable_params =
+                    OSSL_FUNC_provider_gettable_params(provider_dispatch);
+                break;
+            case OSSL_FUNC_PROVIDER_GET_PARAMS:
+                prov->get_params =
+                    OSSL_FUNC_provider_get_params(provider_dispatch);
+                break;
+            case OSSL_FUNC_PROVIDER_SELF_TEST:
+                prov->self_test =
+                    OSSL_FUNC_provider_self_test(provider_dispatch);
+                break;
+            case OSSL_FUNC_PROVIDER_GET_CAPABILITIES:
+                prov->get_capabilities =
+                    OSSL_FUNC_provider_get_capabilities(provider_dispatch);
+                break;
+            case OSSL_FUNC_PROVIDER_QUERY_OPERATION:
+                prov->query_operation =
+                    OSSL_FUNC_provider_query_operation(provider_dispatch);
+                break;
+            case OSSL_FUNC_PROVIDER_UNQUERY_OPERATION:
+                prov->unquery_operation =
+                    OSSL_FUNC_provider_unquery_operation(provider_dispatch);
+                break;
 #ifndef OPENSSL_NO_ERR
 # ifndef FIPS_MODULE
-        case OSSL_FUNC_PROVIDER_GET_REASON_STRINGS:
-            p_get_reason_strings =
-                OSSL_FUNC_provider_get_reason_strings(provider_dispatch);
-            break;
+            case OSSL_FUNC_PROVIDER_GET_REASON_STRINGS:
+                p_get_reason_strings =
+                    OSSL_FUNC_provider_get_reason_strings(provider_dispatch);
+                break;
 # endif
 #endif
+            }
         }
     }
 
@@ -585,7 +1032,7 @@ static int provider_activate(OSSL_PROVIDER *prov)
         cnt = 0;
         while (reasonstrings[cnt].id != 0) {
             if (ERR_GET_LIB(reasonstrings[cnt].id) != 0)
-                return 0;
+                goto end;
             cnt++;
         }
         cnt++;                   /* One for the terminating item */
@@ -594,7 +1041,7 @@ static int provider_activate(OSSL_PROVIDER *prov)
         prov->error_strings =
             OPENSSL_zalloc(sizeof(ERR_STRING_DATA) * (cnt + 1));
         if (prov->error_strings == NULL)
-            return 0;
+            goto end;
 
         /*
          * Set the "library" name.
@@ -617,54 +1064,271 @@ static int provider_activate(OSSL_PROVIDER *prov)
 
     /* With this flag set, this provider has become fully "loaded". */
     prov->flag_initialized = 1;
-    return 1;
+    ok = 1;
+
+ end:
+    return ok;
 }
 
-int ossl_provider_activate(OSSL_PROVIDER *prov)
+/*
+ * Deactivate a provider. If upcalls is 0 then we suppress any upcalls to a
+ * parent provider. If removechildren is 0 then we suppress any calls to remove
+ * child providers.
+ * Return -1 on failure and the activation count on success
+ */
+static int provider_deactivate(OSSL_PROVIDER *prov, int upcalls,
+                               int removechildren)
 {
-    if (provider_activate(prov)) {
-        CRYPTO_THREAD_write_lock(prov->store->lock);
-        prov->store->use_fallbacks = 0;
-        CRYPTO_THREAD_unlock(prov->store->lock);
-        return 1;
+    int count;
+    struct provider_store_st *store;
+#ifndef FIPS_MODULE
+    int freeparent = 0;
+#endif
+    int lock = 1;
+
+    if (!ossl_assert(prov != NULL))
+        return -1;
+
+    /*
+     * No need to lock if we've got no store because we've not been shared with
+     * other threads.
+     */
+    store = get_provider_store(prov->libctx);
+    if (store == NULL)
+        lock = 0;
+
+    if (lock && !CRYPTO_THREAD_read_lock(store->lock))
+        return -1;
+    if (lock && !CRYPTO_THREAD_write_lock(prov->flag_lock)) {
+        CRYPTO_THREAD_unlock(store->lock);
+        return -1;
     }
 
-    return 0;
+    CRYPTO_atomic_add(&prov->activatecnt, -1, &count, prov->activatecnt_lock);
+#ifndef FIPS_MODULE
+    if (count >= 1 && prov->ischild && upcalls) {
+        /*
+         * We have had a direct activation in this child libctx so we need to
+         * now down the ref count in the parent provider. We do the actual down
+         * ref outside of the flag_lock, since it could involve getting other
+         * locks.
+         */
+        freeparent = 1;
+    }
+#endif
+
+    if (count < 1)
+        prov->flag_activated = 0;
+#ifndef FIPS_MODULE
+    else
+        removechildren = 0;
+#endif
+
+#ifndef FIPS_MODULE
+    if (removechildren && store != NULL) {
+        int i, max = sk_OSSL_PROVIDER_CHILD_CB_num(store->child_cbs);
+        OSSL_PROVIDER_CHILD_CB *child_cb;
+
+        for (i = 0; i < max; i++) {
+            child_cb = sk_OSSL_PROVIDER_CHILD_CB_value(store->child_cbs, i);
+            child_cb->remove_cb((OSSL_CORE_HANDLE *)prov, child_cb->cbdata);
+        }
+    }
+#endif
+    if (lock) {
+        CRYPTO_THREAD_unlock(prov->flag_lock);
+        CRYPTO_THREAD_unlock(store->lock);
+        /*
+         * This can be done outside the lock. We tolerate other threads getting
+         * the wrong result briefly when creating OSSL_DECODER_CTXs.
+         */
+#ifndef FIPS_MODULE
+        if (count < 1)
+            ossl_decoder_cache_flush(prov->libctx);
+#endif
+    }
+#ifndef FIPS_MODULE
+    if (freeparent)
+        ossl_provider_free_parent(prov, 1);
+#endif
+
+    /* We don't deinit here, that's done in ossl_provider_free() */
+    return count;
 }
 
-void *ossl_provider_ctx(const OSSL_PROVIDER *prov)
+/*
+ * Activate a provider.
+ * Return -1 on failure and the activation count on success
+ */
+static int provider_activate(OSSL_PROVIDER *prov, int lock, int upcalls)
+{
+    int count = -1;
+    struct provider_store_st *store;
+    int ret = 1;
+
+    store = prov->store;
+    /*
+    * If the provider hasn't been added to the store, then we don't need
+    * any locks because we've not shared it with other threads.
+    */
+    if (store == NULL) {
+        lock = 0;
+        if (!provider_init(prov))
+            return -1;
+    }
+
+#ifndef FIPS_MODULE
+    if (prov->ischild && upcalls && !ossl_provider_up_ref_parent(prov, 1))
+        return -1;
+#endif
+
+    if (lock && !CRYPTO_THREAD_read_lock(store->lock)) {
+#ifndef FIPS_MODULE
+        if (prov->ischild && upcalls)
+            ossl_provider_free_parent(prov, 1);
+#endif
+        return -1;
+    }
+
+    if (lock && !CRYPTO_THREAD_write_lock(prov->flag_lock)) {
+        CRYPTO_THREAD_unlock(store->lock);
+#ifndef FIPS_MODULE
+        if (prov->ischild && upcalls)
+            ossl_provider_free_parent(prov, 1);
+#endif
+        return -1;
+    }
+    if (CRYPTO_atomic_add(&prov->activatecnt, 1, &count, prov->activatecnt_lock)) {
+        prov->flag_activated = 1;
+
+        if (count == 1 && store != NULL) {
+            ret = create_provider_children(prov);
+        }
+    }
+    if (lock) {
+        CRYPTO_THREAD_unlock(prov->flag_lock);
+        CRYPTO_THREAD_unlock(store->lock);
+        /*
+         * This can be done outside the lock. We tolerate other threads getting
+         * the wrong result briefly when creating OSSL_DECODER_CTXs.
+         */
+#ifndef FIPS_MODULE
+        if (count == 1)
+            ossl_decoder_cache_flush(prov->libctx);
+#endif
+    }
+
+    if (!ret)
+        return -1;
+
+    return count;
+}
+
+static int provider_flush_store_cache(const OSSL_PROVIDER *prov)
 {
-    return prov->provctx;
+    struct provider_store_st *store;
+    int freeing;
+
+    if ((store = get_provider_store(prov->libctx)) == NULL)
+        return 0;
+
+    if (!CRYPTO_THREAD_read_lock(store->lock))
+        return 0;
+    freeing = store->freeing;
+    CRYPTO_THREAD_unlock(store->lock);
+
+    if (!freeing) {
+        int acc
+            = evp_method_store_cache_flush(prov->libctx)
+#ifndef FIPS_MODULE
+            + ossl_encoder_store_cache_flush(prov->libctx)
+            + ossl_decoder_store_cache_flush(prov->libctx)
+            + ossl_store_loader_store_cache_flush(prov->libctx)
+#endif
+            ;
+
+#ifndef FIPS_MODULE
+        return acc == 4;
+#else
+        return acc == 1;
+#endif
+    }
+    return 1;
 }
 
+static int provider_remove_store_methods(OSSL_PROVIDER *prov)
+{
+    struct provider_store_st *store;
+    int freeing;
 
-static int provider_forall_loaded(struct provider_store_st *store,
-                                  int *found_activated,
-                                  int (*cb)(OSSL_PROVIDER *provider,
-                                            void *cbdata),
-                                  void *cbdata)
+    if ((store = get_provider_store(prov->libctx)) == NULL)
+        return 0;
+
+    if (!CRYPTO_THREAD_read_lock(store->lock))
+        return 0;
+    freeing = store->freeing;
+    CRYPTO_THREAD_unlock(store->lock);
+
+    if (!freeing) {
+        int acc;
+
+        if (!CRYPTO_THREAD_write_lock(prov->opbits_lock))
+            return 0;
+        OPENSSL_free(prov->operation_bits);
+        prov->operation_bits = NULL;
+        prov->operation_bits_sz = 0;
+        CRYPTO_THREAD_unlock(prov->opbits_lock);
+
+        acc = evp_method_store_remove_all_provided(prov)
+#ifndef FIPS_MODULE
+            + ossl_encoder_store_remove_all_provided(prov)
+            + ossl_decoder_store_remove_all_provided(prov)
+            + ossl_store_loader_store_remove_all_provided(prov)
+#endif
+            ;
+
+#ifndef FIPS_MODULE
+        return acc == 4;
+#else
+        return acc == 1;
+#endif
+    }
+    return 1;
+}
+
+int ossl_provider_activate(OSSL_PROVIDER *prov, int upcalls, int aschild)
 {
-    int i;
-    int ret = 1;
-    int num_provs;
+    int count;
 
-    num_provs = sk_OSSL_PROVIDER_num(store->providers);
+    if (prov == NULL)
+        return 0;
+#ifndef FIPS_MODULE
+    /*
+     * If aschild is true, then we only actually do the activation if the
+     * provider is a child. If its not, this is still success.
+     */
+    if (aschild && !prov->ischild)
+        return 1;
+#endif
+    if ((count = provider_activate(prov, 1, upcalls)) > 0)
+        return count == 1 ? provider_flush_store_cache(prov) : 1;
+
+    return 0;
+}
 
-    if (found_activated != NULL)
-        *found_activated = 0;
-    for (i = 0; i < num_provs; i++) {
-        OSSL_PROVIDER *prov =
-            sk_OSSL_PROVIDER_value(store->providers, i);
+int ossl_provider_deactivate(OSSL_PROVIDER *prov, int removechildren)
+{
+    int count;
 
-        if (prov->flag_initialized) {
-            if (found_activated != NULL)
-                *found_activated = 1;
-            if (!(ret = cb(prov, cbdata)))
-                break;
-        }
-    }
+    if (prov == NULL
+            || (count = provider_deactivate(prov, 1, removechildren)) < 0)
+        return 0;
+    return count == 0 ? provider_remove_store_methods(prov) : 1;
+}
 
-    return ret;
+void *ossl_provider_ctx(const OSSL_PROVIDER *prov)
+{
+    return prov != NULL ? prov->provctx : NULL;
 }
 
 /*
@@ -672,99 +1336,228 @@ static int provider_forall_loaded(struct provider_store_st *store,
  * and then sets store->use_fallbacks = 0, so the second call and so on is
  * effectively a no-op.
  */
-static void provider_activate_fallbacks(struct provider_store_st *store)
+static int provider_activate_fallbacks(struct provider_store_st *store)
 {
-    if (store->use_fallbacks) {
-        int num_provs = sk_OSSL_PROVIDER_num(store->providers);
-        int activated_fallback_count = 0;
-        int i;
+    int use_fallbacks;
+    int activated_fallback_count = 0;
+    int ret = 0;
+    const OSSL_PROVIDER_INFO *p;
 
-        for (i = 0; i < num_provs; i++) {
-            OSSL_PROVIDER *prov = sk_OSSL_PROVIDER_value(store->providers, i);
+    if (!CRYPTO_THREAD_read_lock(store->lock))
+        return 0;
+    use_fallbacks = store->use_fallbacks;
+    CRYPTO_THREAD_unlock(store->lock);
+    if (!use_fallbacks)
+        return 1;
 
-            /*
-             * Activated fallback providers get an extra refcount, to
-             * simulate a regular load.
-             * Note that we don't care if the activation succeeds or not,
-             * other than to maintain a correct refcount.  If the activation
-             * doesn't succeed, then any future attempt to use the fallback
-             * provider will fail anyway.
-             */
-            if (prov->flag_fallback) {
-                if (ossl_provider_up_ref(prov)) {
-                    if (!provider_activate(prov)) {
-                        ossl_provider_free(prov);
-                    } else {
-                        prov->flag_activated_as_fallback = 1;
-                        activated_fallback_count++;
-                    }
-                }
-            }
-        }
+    if (!CRYPTO_THREAD_write_lock(store->lock))
+        return 0;
+    /* Check again, just in case another thread changed it */
+    use_fallbacks = store->use_fallbacks;
+    if (!use_fallbacks) {
+        CRYPTO_THREAD_unlock(store->lock);
+        return 1;
+    }
+
+    for (p = ossl_predefined_providers; p->name != NULL; p++) {
+        OSSL_PROVIDER *prov = NULL;
 
+        if (!p->is_fallback)
+            continue;
         /*
-         * We assume that all fallbacks have been added to the store before
-         * any fallback is activated.
-         * TODO: We may have to reconsider this, IF we find ourselves adding
-         * fallbacks after any previous fallback has been activated.
+         * We use the internal constructor directly here,
+         * otherwise we get a call loop
          */
-        if (activated_fallback_count > 0)
-            store->use_fallbacks = 0;
+        prov = provider_new(p->name, p->init, NULL);
+        if (prov == NULL)
+            goto err;
+        prov->libctx = store->libctx;
+#ifndef FIPS_MODULE
+        prov->error_lib = ERR_get_next_error_library();
+#endif
+
+        /*
+         * We are calling provider_activate while holding the store lock. This
+         * means the init function will be called while holding a lock. Normally
+         * we try to avoid calling a user callback while holding a lock.
+         * However, fallbacks are never third party providers so we accept this.
+         */
+        if (provider_activate(prov, 0, 0) < 0) {
+            ossl_provider_free(prov);
+            goto err;
+        }
+        prov->store = store;
+        if (sk_OSSL_PROVIDER_push(store->providers, prov) == 0) {
+            ossl_provider_free(prov);
+            goto err;
+        }
+        activated_fallback_count++;
+    }
+
+    if (activated_fallback_count > 0) {
+        store->use_fallbacks = 0;
+        ret = 1;
     }
+ err:
+    CRYPTO_THREAD_unlock(store->lock);
+    return ret;
 }
 
-int ossl_provider_forall_loaded(OPENSSL_CTX *ctx,
-                                int (*cb)(OSSL_PROVIDER *provider,
-                                          void *cbdata),
-                                void *cbdata)
+int ossl_provider_doall_activated(OSSL_LIB_CTX *ctx,
+                                  int (*cb)(OSSL_PROVIDER *provider,
+                                            void *cbdata),
+                                  void *cbdata)
 {
-    int ret = 1;
+    int ret = 0, curr, max, ref = 0;
     struct provider_store_st *store = get_provider_store(ctx);
+    STACK_OF(OSSL_PROVIDER) *provs = NULL;
 
-#ifndef FIPS_MODULE
+#if !defined(FIPS_MODULE) && !defined(OPENSSL_NO_AUTOLOAD_CONFIG)
     /*
      * Make sure any providers are loaded from config before we try to use
      * them.
      */
-    OPENSSL_init_crypto(OPENSSL_INIT_LOAD_CONFIG, NULL);
+    if (ossl_lib_ctx_is_default(ctx))
+        OPENSSL_init_crypto(OPENSSL_INIT_LOAD_CONFIG, NULL);
 #endif
 
-    if (store != NULL) {
-        CRYPTO_THREAD_read_lock(store->lock);
+    if (store == NULL)
+        return 1;
+    if (!provider_activate_fallbacks(store))
+        return 0;
 
-        provider_activate_fallbacks(store);
+    /*
+     * Under lock, grab a copy of the provider list and up_ref each
+     * provider so that they don't disappear underneath us.
+     */
+    if (!CRYPTO_THREAD_read_lock(store->lock))
+        return 0;
+    provs = sk_OSSL_PROVIDER_dup(store->providers);
+    if (provs == NULL) {
+        CRYPTO_THREAD_unlock(store->lock);
+        return 0;
+    }
+    max = sk_OSSL_PROVIDER_num(provs);
+    /*
+     * We work backwards through the stack so that we can safely delete items
+     * as we go.
+     */
+    for (curr = max - 1; curr >= 0; curr--) {
+        OSSL_PROVIDER *prov = sk_OSSL_PROVIDER_value(provs, curr);
 
-        /*
-         * Now, we sweep through all providers
-         */
-        ret = provider_forall_loaded(store, NULL, cb, cbdata);
+        if (!CRYPTO_THREAD_read_lock(prov->flag_lock))
+            goto err_unlock;
+        if (prov->flag_activated) {
+            /*
+             * We call CRYPTO_UP_REF directly rather than ossl_provider_up_ref
+             * to avoid upping the ref count on the parent provider, which we
+             * must not do while holding locks.
+             */
+            if (CRYPTO_UP_REF(&prov->refcnt, &ref) <= 0) {
+                CRYPTO_THREAD_unlock(prov->flag_lock);
+                goto err_unlock;
+            }
+            /*
+             * It's already activated, but we up the activated count to ensure
+             * it remains activated until after we've called the user callback.
+             * In theory this could mean the parent provider goes inactive,
+             * whilst still activated in the child for a short period. That's ok.
+             */
+            if (!CRYPTO_atomic_add(&prov->activatecnt, 1, &ref,
+                                   prov->activatecnt_lock)) {
+                CRYPTO_DOWN_REF(&prov->refcnt, &ref);
+                CRYPTO_THREAD_unlock(prov->flag_lock);
+                goto err_unlock;
+            }
+        } else {
+            sk_OSSL_PROVIDER_delete(provs, curr);
+            max--;
+        }
+        CRYPTO_THREAD_unlock(prov->flag_lock);
+    }
+    CRYPTO_THREAD_unlock(store->lock);
 
-        CRYPTO_THREAD_unlock(store->lock);
+    /*
+     * Now, we sweep through all providers not under lock
+     */
+    for (curr = 0; curr < max; curr++) {
+        OSSL_PROVIDER *prov = sk_OSSL_PROVIDER_value(provs, curr);
+
+        if (!cb(prov, cbdata)) {
+            curr = -1;
+            goto finish;
+        }
     }
+    curr = -1;
 
-    return ret;
-}
+    ret = 1;
+    goto finish;
 
-int ossl_provider_available(OSSL_PROVIDER *prov)
-{
-    if (prov != NULL) {
-        CRYPTO_THREAD_read_lock(prov->store->lock);
-        provider_activate_fallbacks(prov->store);
-        CRYPTO_THREAD_unlock(prov->store->lock);
+ err_unlock:
+    CRYPTO_THREAD_unlock(store->lock);
+ finish:
+    /*
+     * The pop_free call doesn't do what we want on an error condition. We
+     * either start from the first item in the stack, or part way through if
+     * we only processed some of the items.
+     */
+    for (curr++; curr < max; curr++) {
+        OSSL_PROVIDER *prov = sk_OSSL_PROVIDER_value(provs, curr);
 
-        return prov->flag_initialized;
+        if (!CRYPTO_atomic_add(&prov->activatecnt, -1, &ref,
+                               prov->activatecnt_lock)) {
+            ret = 0;
+            continue;
+        }
+        if (ref < 1) {
+            /*
+             * Looks like we need to deactivate properly. We could just have
+             * done this originally, but it involves taking a write lock so
+             * we avoid it. We up the count again and do a full deactivation
+             */
+            if (CRYPTO_atomic_add(&prov->activatecnt, 1, &ref,
+                                  prov->activatecnt_lock))
+                provider_deactivate(prov, 0, 1);
+            else
+                ret = 0;
+        }
+        /*
+         * As above where we did the up-ref, we don't call ossl_provider_free
+         * to avoid making upcalls. There should always be at least one ref
+         * to the provider in the store, so this should never drop to 0.
+         */
+        if (!CRYPTO_DOWN_REF(&prov->refcnt, &ref)) {
+            ret = 0;
+            continue;
+        }
+        /*
+         * Not much we can do if this assert ever fails. So we don't use
+         * ossl_assert here.
+         */
+        assert(ref > 0);
     }
-    return 0;
+    sk_OSSL_PROVIDER_free(provs);
+    return ret;
 }
 
-/* Setters of Provider Object data */
-int ossl_provider_set_fallback(OSSL_PROVIDER *prov)
+int OSSL_PROVIDER_available(OSSL_LIB_CTX *libctx, const char *name)
 {
-    if (prov == NULL)
+    OSSL_PROVIDER *prov = NULL;
+    int available = 0;
+    struct provider_store_st *store = get_provider_store(libctx);
+
+    if (store == NULL || !provider_activate_fallbacks(store))
         return 0;
 
-    prov->flag_fallback = 1;
-    return 1;
+    prov = ossl_provider_find(libctx, name, 0);
+    if (prov != NULL) {
+        if (!CRYPTO_THREAD_read_lock(prov->flag_lock))
+            return 0;
+        available = prov->flag_activated;
+        CRYPTO_THREAD_unlock(prov->flag_lock);
+        ossl_provider_free(prov);
+    }
+    return available;
 }
 
 /* Getters of Provider Object data */
@@ -805,16 +1598,27 @@ void *ossl_provider_prov_ctx(const OSSL_PROVIDER *prov)
     return NULL;
 }
 
-OPENSSL_CTX *ossl_provider_library_context(const OSSL_PROVIDER *prov)
+const OSSL_DISPATCH *ossl_provider_get0_dispatch(const OSSL_PROVIDER *prov)
+{
+    if (prov != NULL)
+        return prov->dispatch;
+
+    return NULL;
+}
+
+OSSL_LIB_CTX *ossl_provider_libctx(const OSSL_PROVIDER *prov)
 {
-    /* TODO(3.0) just: return prov->libctx; */
     return prov != NULL ? prov->libctx : NULL;
 }
 
 /* Wrappers around calls to the provider */
 void ossl_provider_teardown(const OSSL_PROVIDER *prov)
 {
-    if (prov->teardown != NULL)
+    if (prov->teardown != NULL
+#ifndef FIPS_MODULE
+            && !prov->ischild
+#endif
+       )
         prov->teardown(prov->provctx);
 }
 
@@ -838,7 +1642,7 @@ int ossl_provider_self_test(const OSSL_PROVIDER *prov)
         return 1;
     ret = prov->self_test(prov->provctx);
     if (ret == 0)
-        evp_method_store_flush(ossl_provider_library_context(prov));
+        (void)provider_remove_store_methods((OSSL_PROVIDER *)prov);
     return ret;
 }
 
@@ -855,7 +1659,25 @@ const OSSL_ALGORITHM *ossl_provider_query_operation(const OSSL_PROVIDER *prov,
                                                     int operation_id,
                                                     int *no_cache)
 {
-    return prov->query_operation(prov->provctx, operation_id, no_cache);
+    const OSSL_ALGORITHM *res;
+
+    if (prov->query_operation == NULL)
+        return NULL;
+    res = prov->query_operation(prov->provctx, operation_id, no_cache);
+#if defined(OPENSSL_NO_CACHED_FETCH)
+    /* Forcing the non-caching of queries */
+    if (no_cache != NULL)
+        *no_cache = 1;
+#endif
+    return res;
+}
+
+void ossl_provider_unquery_operation(const OSSL_PROVIDER *prov,
+                                     int operation_id,
+                                     const OSSL_ALGORITHM *algs)
+{
+    if (prov->unquery_operation != NULL)
+        prov->unquery_operation(prov->provctx, operation_id, algs);
 }
 
 int ossl_provider_set_operation_bit(OSSL_PROVIDER *provider, size_t bitnum)
@@ -863,17 +1685,23 @@ int ossl_provider_set_operation_bit(OSSL_PROVIDER *provider, size_t bitnum)
     size_t byte = bitnum / 8;
     unsigned char bit = (1 << (bitnum % 8)) & 0xFF;
 
+    if (!CRYPTO_THREAD_write_lock(provider->opbits_lock))
+        return 0;
     if (provider->operation_bits_sz <= byte) {
-        provider->operation_bits = OPENSSL_realloc(provider->operation_bits,
-                                                   byte + 1);
-        if (provider->operation_bits == NULL) {
-            ERR_raise(ERR_LIB_CRYPTO, ERR_R_MALLOC_FAILURE);
+        unsigned char *tmp = OPENSSL_realloc(provider->operation_bits,
+                                             byte + 1);
+
+        if (tmp == NULL) {
+            CRYPTO_THREAD_unlock(provider->opbits_lock);
             return 0;
         }
+        provider->operation_bits = tmp;
         memset(provider->operation_bits + provider->operation_bits_sz,
                '\0', byte + 1 - provider->operation_bits_sz);
+        provider->operation_bits_sz = byte + 1;
     }
     provider->operation_bits[byte] |= bit;
+    CRYPTO_THREAD_unlock(provider->opbits_lock);
     return 1;
 }
 
@@ -889,11 +1717,174 @@ int ossl_provider_test_operation_bit(OSSL_PROVIDER *provider, size_t bitnum,
     }
 
     *result = 0;
+    if (!CRYPTO_THREAD_read_lock(provider->opbits_lock))
+        return 0;
     if (provider->operation_bits_sz > byte)
         *result = ((provider->operation_bits[byte] & bit) != 0);
+    CRYPTO_THREAD_unlock(provider->opbits_lock);
+    return 1;
+}
+
+#ifndef FIPS_MODULE
+const OSSL_CORE_HANDLE *ossl_provider_get_parent(OSSL_PROVIDER *prov)
+{
+    return prov->handle;
+}
+
+int ossl_provider_is_child(const OSSL_PROVIDER *prov)
+{
+    return prov->ischild;
+}
+
+int ossl_provider_set_child(OSSL_PROVIDER *prov, const OSSL_CORE_HANDLE *handle)
+{
+    prov->handle = handle;
+    prov->ischild = 1;
+
+    return 1;
+}
+
+int ossl_provider_default_props_update(OSSL_LIB_CTX *libctx, const char *props)
+{
+#ifndef FIPS_MODULE
+    struct provider_store_st *store = NULL;
+    int i, max;
+    OSSL_PROVIDER_CHILD_CB *child_cb;
+
+    if ((store = get_provider_store(libctx)) == NULL)
+        return 0;
+
+    if (!CRYPTO_THREAD_read_lock(store->lock))
+        return 0;
+
+    max = sk_OSSL_PROVIDER_CHILD_CB_num(store->child_cbs);
+    for (i = 0; i < max; i++) {
+        child_cb = sk_OSSL_PROVIDER_CHILD_CB_value(store->child_cbs, i);
+        child_cb->global_props_cb(props, child_cb->cbdata);
+    }
+
+    CRYPTO_THREAD_unlock(store->lock);
+#endif
     return 1;
 }
 
+static int ossl_provider_register_child_cb(const OSSL_CORE_HANDLE *handle,
+                                           int (*create_cb)(
+                                               const OSSL_CORE_HANDLE *provider,
+                                               void *cbdata),
+                                           int (*remove_cb)(
+                                               const OSSL_CORE_HANDLE *provider,
+                                               void *cbdata),
+                                           int (*global_props_cb)(
+                                               const char *props,
+                                               void *cbdata),
+                                           void *cbdata)
+{
+    /*
+     * This is really an OSSL_PROVIDER that we created and cast to
+     * OSSL_CORE_HANDLE originally. Therefore it is safe to cast it back.
+     */
+    OSSL_PROVIDER *thisprov = (OSSL_PROVIDER *)handle;
+    OSSL_PROVIDER *prov;
+    OSSL_LIB_CTX *libctx = thisprov->libctx;
+    struct provider_store_st *store = NULL;
+    int ret = 0, i, max;
+    OSSL_PROVIDER_CHILD_CB *child_cb;
+    char *propsstr = NULL;
+
+    if ((store = get_provider_store(libctx)) == NULL)
+        return 0;
+
+    child_cb = OPENSSL_malloc(sizeof(*child_cb));
+    if (child_cb == NULL)
+        return 0;
+    child_cb->prov = thisprov;
+    child_cb->create_cb = create_cb;
+    child_cb->remove_cb = remove_cb;
+    child_cb->global_props_cb = global_props_cb;
+    child_cb->cbdata = cbdata;
+
+    if (!CRYPTO_THREAD_write_lock(store->lock)) {
+        OPENSSL_free(child_cb);
+        return 0;
+    }
+    propsstr = evp_get_global_properties_str(libctx, 0);
+
+    if (propsstr != NULL) {
+        global_props_cb(propsstr, cbdata);
+        OPENSSL_free(propsstr);
+    }
+    max = sk_OSSL_PROVIDER_num(store->providers);
+    for (i = 0; i < max; i++) {
+        int activated;
+
+        prov = sk_OSSL_PROVIDER_value(store->providers, i);
+
+        if (!CRYPTO_THREAD_read_lock(prov->flag_lock))
+            break;
+        activated = prov->flag_activated;
+        CRYPTO_THREAD_unlock(prov->flag_lock);
+        /*
+         * We hold the store lock while calling the user callback. This means
+         * that the user callback must be short and simple and not do anything
+         * likely to cause a deadlock. We don't hold the flag_lock during this
+         * call. In theory this means that another thread could deactivate it
+         * while we are calling create. This is ok because the other thread
+         * will also call remove_cb, but won't be able to do so until we release
+         * the store lock.
+         */
+        if (activated && !create_cb((OSSL_CORE_HANDLE *)prov, cbdata))
+            break;
+    }
+    if (i == max) {
+        /* Success */
+        ret = sk_OSSL_PROVIDER_CHILD_CB_push(store->child_cbs, child_cb);
+    }
+    if (i != max || ret <= 0) {
+        /* Failed during creation. Remove everything we just added */
+        for (; i >= 0; i--) {
+            prov = sk_OSSL_PROVIDER_value(store->providers, i);
+            remove_cb((OSSL_CORE_HANDLE *)prov, cbdata);
+        }
+        OPENSSL_free(child_cb);
+        ret = 0;
+    }
+    CRYPTO_THREAD_unlock(store->lock);
+
+    return ret;
+}
+
+static void ossl_provider_deregister_child_cb(const OSSL_CORE_HANDLE *handle)
+{
+    /*
+     * This is really an OSSL_PROVIDER that we created and cast to
+     * OSSL_CORE_HANDLE originally. Therefore it is safe to cast it back.
+     */
+    OSSL_PROVIDER *thisprov = (OSSL_PROVIDER *)handle;
+    OSSL_LIB_CTX *libctx = thisprov->libctx;
+    struct provider_store_st *store = NULL;
+    int i, max;
+    OSSL_PROVIDER_CHILD_CB *child_cb;
+
+    if ((store = get_provider_store(libctx)) == NULL)
+        return;
+
+    if (!CRYPTO_THREAD_write_lock(store->lock))
+        return;
+    max = sk_OSSL_PROVIDER_CHILD_CB_num(store->child_cbs);
+    for (i = 0; i < max; i++) {
+        child_cb = sk_OSSL_PROVIDER_CHILD_CB_value(store->child_cbs, i);
+        if (child_cb->prov == thisprov) {
+            /* Found an entry */
+            sk_OSSL_PROVIDER_CHILD_CB_delete(store->child_cbs, i);
+            OPENSSL_free(child_cb);
+            break;
+        }
+    }
+    CRYPTO_THREAD_unlock(store->lock);
+}
+#endif
+
 /*-
  * Core functions for the provider
  * ===============================
@@ -924,8 +1915,8 @@ static const OSSL_PARAM param_types[] = {
  */
 static OSSL_FUNC_core_gettable_params_fn core_gettable_params;
 static OSSL_FUNC_core_get_params_fn core_get_params;
+static OSSL_FUNC_core_get_libctx_fn core_get_libctx;
 static OSSL_FUNC_core_thread_start_fn core_thread_start;
-static OSSL_FUNC_core_get_library_context_fn core_get_libctx;
 #ifndef FIPS_MODULE
 static OSSL_FUNC_core_new_error_fn core_new_error;
 static OSSL_FUNC_core_set_error_debug_fn core_set_error_debug;
@@ -933,6 +1924,48 @@ static OSSL_FUNC_core_vset_error_fn core_vset_error;
 static OSSL_FUNC_core_set_error_mark_fn core_set_error_mark;
 static OSSL_FUNC_core_clear_last_error_mark_fn core_clear_last_error_mark;
 static OSSL_FUNC_core_pop_error_to_mark_fn core_pop_error_to_mark;
+OSSL_FUNC_BIO_new_file_fn ossl_core_bio_new_file;
+OSSL_FUNC_BIO_new_membuf_fn ossl_core_bio_new_mem_buf;
+OSSL_FUNC_BIO_read_ex_fn ossl_core_bio_read_ex;
+OSSL_FUNC_BIO_write_ex_fn ossl_core_bio_write_ex;
+OSSL_FUNC_BIO_gets_fn ossl_core_bio_gets;
+OSSL_FUNC_BIO_puts_fn ossl_core_bio_puts;
+OSSL_FUNC_BIO_up_ref_fn ossl_core_bio_up_ref;
+OSSL_FUNC_BIO_free_fn ossl_core_bio_free;
+OSSL_FUNC_BIO_vprintf_fn ossl_core_bio_vprintf;
+OSSL_FUNC_BIO_vsnprintf_fn BIO_vsnprintf;
+static OSSL_FUNC_self_test_cb_fn core_self_test_get_callback;
+static OSSL_FUNC_get_entropy_fn rand_get_entropy;
+static OSSL_FUNC_get_user_entropy_fn rand_get_user_entropy;
+static OSSL_FUNC_cleanup_entropy_fn rand_cleanup_entropy;
+static OSSL_FUNC_cleanup_user_entropy_fn rand_cleanup_user_entropy;
+static OSSL_FUNC_get_nonce_fn rand_get_nonce;
+static OSSL_FUNC_get_user_nonce_fn rand_get_user_nonce;
+static OSSL_FUNC_cleanup_nonce_fn rand_cleanup_nonce;
+static OSSL_FUNC_cleanup_user_nonce_fn rand_cleanup_user_nonce;
+#endif
+OSSL_FUNC_CRYPTO_malloc_fn CRYPTO_malloc;
+OSSL_FUNC_CRYPTO_zalloc_fn CRYPTO_zalloc;
+OSSL_FUNC_CRYPTO_free_fn CRYPTO_free;
+OSSL_FUNC_CRYPTO_clear_free_fn CRYPTO_clear_free;
+OSSL_FUNC_CRYPTO_realloc_fn CRYPTO_realloc;
+OSSL_FUNC_CRYPTO_clear_realloc_fn CRYPTO_clear_realloc;
+OSSL_FUNC_CRYPTO_secure_malloc_fn CRYPTO_secure_malloc;
+OSSL_FUNC_CRYPTO_secure_zalloc_fn CRYPTO_secure_zalloc;
+OSSL_FUNC_CRYPTO_secure_free_fn CRYPTO_secure_free;
+OSSL_FUNC_CRYPTO_secure_clear_free_fn CRYPTO_secure_clear_free;
+OSSL_FUNC_CRYPTO_secure_allocated_fn CRYPTO_secure_allocated;
+OSSL_FUNC_OPENSSL_cleanse_fn OPENSSL_cleanse;
+#ifndef FIPS_MODULE
+OSSL_FUNC_provider_register_child_cb_fn ossl_provider_register_child_cb;
+OSSL_FUNC_provider_deregister_child_cb_fn ossl_provider_deregister_child_cb;
+static OSSL_FUNC_provider_name_fn core_provider_get0_name;
+static OSSL_FUNC_provider_get0_provider_ctx_fn core_provider_get0_provider_ctx;
+static OSSL_FUNC_provider_get0_dispatch_fn core_provider_get0_dispatch;
+static OSSL_FUNC_provider_up_ref_fn core_provider_up_ref_intern;
+static OSSL_FUNC_provider_free_fn core_provider_free_intern;
+static OSSL_FUNC_core_obj_add_sigid_fn core_obj_add_sigid;
+static OSSL_FUNC_core_obj_create_fn core_obj_create;
 #endif
 
 static const OSSL_PARAM *core_gettable_params(const OSSL_CORE_HANDLE *handle)
@@ -981,11 +2014,19 @@ static OPENSSL_CORE_CTX *core_get_libctx(const OSSL_CORE_HANDLE *handle)
      */
     OSSL_PROVIDER *prov = (OSSL_PROVIDER *)handle;
 
-    return (OPENSSL_CORE_CTX *)ossl_provider_library_context(prov);
+    /*
+     * Using ossl_provider_libctx would be wrong as that returns
+     * NULL for |prov| == NULL and NULL libctx has a special meaning
+     * that does not apply here. Here |prov| == NULL can happen only in
+     * case of a coding error.
+     */
+    assert(prov != NULL);
+    return (OPENSSL_CORE_CTX *)prov->libctx;
 }
 
 static int core_thread_start(const OSSL_CORE_HANDLE *handle,
-                             OSSL_thread_stop_handler_fn handfn)
+                             OSSL_thread_stop_handler_fn handfn,
+                             void *arg)
 {
     /*
      * We created this object originally and we know it is actually an
@@ -993,7 +2034,7 @@ static int core_thread_start(const OSSL_CORE_HANDLE *handle,
      */
     OSSL_PROVIDER *prov = (OSSL_PROVIDER *)handle;
 
-    return ossl_init_thread_start(prov, prov->provctx, handfn);
+    return ossl_init_thread_start(prov, arg, handfn);
 }
 
 /*
@@ -1003,8 +2044,8 @@ static int core_thread_start(const OSSL_CORE_HANDLE *handle,
  */
 #ifndef FIPS_MODULE
 /*
- * TODO(3.0) These error functions should use |handle| to select the proper
- * library context to report in the correct error stack, at least if error
+ * These error functions should use |handle| to select the proper
+ * library context to report in the correct error stack if error
  * stacks become tied to the library context.
  * We cannot currently do that since there's no support for it in the
  * ERR subsystem.
@@ -1055,16 +2096,147 @@ static int core_pop_error_to_mark(const OSSL_CORE_HANDLE *handle)
 {
     return ERR_pop_to_mark();
 }
+
+static void core_self_test_get_callback(OPENSSL_CORE_CTX *libctx,
+                                        OSSL_CALLBACK **cb, void **cbarg)
+{
+    OSSL_SELF_TEST_get_callback((OSSL_LIB_CTX *)libctx, cb, cbarg);
+}
+
+static size_t rand_get_entropy(const OSSL_CORE_HANDLE *handle,
+                               unsigned char **pout, int entropy,
+                               size_t min_len, size_t max_len)
+{
+    return ossl_rand_get_entropy((OSSL_LIB_CTX *)core_get_libctx(handle),
+                                 pout, entropy, min_len, max_len);
+}
+
+static size_t rand_get_user_entropy(const OSSL_CORE_HANDLE *handle,
+                                    unsigned char **pout, int entropy,
+                                    size_t min_len, size_t max_len)
+{
+    return ossl_rand_get_user_entropy((OSSL_LIB_CTX *)core_get_libctx(handle),
+                                      pout, entropy, min_len, max_len);
+}
+
+static void rand_cleanup_entropy(const OSSL_CORE_HANDLE *handle,
+                                 unsigned char *buf, size_t len)
+{
+    ossl_rand_cleanup_entropy((OSSL_LIB_CTX *)core_get_libctx(handle),
+                              buf, len);
+}
+
+static void rand_cleanup_user_entropy(const OSSL_CORE_HANDLE *handle,
+                                      unsigned char *buf, size_t len)
+{
+    ossl_rand_cleanup_user_entropy((OSSL_LIB_CTX *)core_get_libctx(handle),
+                                   buf, len);
+}
+
+static size_t rand_get_nonce(const OSSL_CORE_HANDLE *handle,
+                             unsigned char **pout,
+                             size_t min_len, size_t max_len,
+                             const void *salt, size_t salt_len)
+{
+    return ossl_rand_get_nonce((OSSL_LIB_CTX *)core_get_libctx(handle),
+                               pout, min_len, max_len, salt, salt_len);
+}
+
+static size_t rand_get_user_nonce(const OSSL_CORE_HANDLE *handle,
+                                  unsigned char **pout,
+                                  size_t min_len, size_t max_len,
+                                  const void *salt, size_t salt_len)
+{
+    return ossl_rand_get_user_nonce((OSSL_LIB_CTX *)core_get_libctx(handle),
+                                    pout, min_len, max_len, salt, salt_len);
+}
+
+static void rand_cleanup_nonce(const OSSL_CORE_HANDLE *handle,
+                               unsigned char *buf, size_t len)
+{
+    ossl_rand_cleanup_nonce((OSSL_LIB_CTX *)core_get_libctx(handle),
+                            buf, len);
+}
+
+static void rand_cleanup_user_nonce(const OSSL_CORE_HANDLE *handle,
+                               unsigned char *buf, size_t len)
+{
+    ossl_rand_cleanup_user_nonce((OSSL_LIB_CTX *)core_get_libctx(handle),
+                                 buf, len);
+}
+
+static const char *core_provider_get0_name(const OSSL_CORE_HANDLE *prov)
+{
+    return OSSL_PROVIDER_get0_name((const OSSL_PROVIDER *)prov);
+}
+
+static void *core_provider_get0_provider_ctx(const OSSL_CORE_HANDLE *prov)
+{
+    return OSSL_PROVIDER_get0_provider_ctx((const OSSL_PROVIDER *)prov);
+}
+
+static const OSSL_DISPATCH *
+core_provider_get0_dispatch(const OSSL_CORE_HANDLE *prov)
+{
+    return OSSL_PROVIDER_get0_dispatch((const OSSL_PROVIDER *)prov);
+}
+
+static int core_provider_up_ref_intern(const OSSL_CORE_HANDLE *prov,
+                                       int activate)
+{
+    return provider_up_ref_intern((OSSL_PROVIDER *)prov, activate);
+}
+
+static int core_provider_free_intern(const OSSL_CORE_HANDLE *prov,
+                                     int deactivate)
+{
+    return provider_free_intern((OSSL_PROVIDER *)prov, deactivate);
+}
+
+static int core_obj_add_sigid(const OSSL_CORE_HANDLE *prov,
+                              const char *sign_name, const char *digest_name,
+                              const char *pkey_name)
+{
+    int sign_nid = OBJ_txt2nid(sign_name);
+    int digest_nid = NID_undef;
+    int pkey_nid = OBJ_txt2nid(pkey_name);
+
+    if (digest_name != NULL && digest_name[0] != '\0'
+        && (digest_nid = OBJ_txt2nid(digest_name)) == NID_undef)
+            return 0;
+
+    if (sign_nid == NID_undef)
+        return 0;
+
+    /*
+     * Check if it already exists. This is a success if so (even if we don't
+     * have nids for the digest/pkey)
+     */
+    if (OBJ_find_sigid_algs(sign_nid, NULL, NULL))
+        return 1;
+
+    if (pkey_nid == NID_undef)
+        return 0;
+
+    return OBJ_add_sigid(sign_nid, digest_nid, pkey_nid);
+}
+
+static int core_obj_create(const OSSL_CORE_HANDLE *prov, const char *oid,
+                           const char *sn, const char *ln)
+{
+    /* Check if it already exists and create it if not */
+    return OBJ_txt2nid(oid) != NID_undef
+           || OBJ_create(oid, sn, ln) != NID_undef;
+}
 #endif /* FIPS_MODULE */
 
 /*
- * Functions provided by the core.  Blank line separates "families" of related
- * functions.
+ * Functions provided by the core.
  */
 static const OSSL_DISPATCH core_dispatch_[] = {
     { OSSL_FUNC_CORE_GETTABLE_PARAMS, (void (*)(void))core_gettable_params },
     { OSSL_FUNC_CORE_GET_PARAMS, (void (*)(void))core_get_params },
-    { OSSL_FUNC_CORE_GET_LIBRARY_CONTEXT, (void (*)(void))core_get_libctx },
+    { OSSL_FUNC_CORE_GET_LIBCTX, (void (*)(void))core_get_libctx },
     { OSSL_FUNC_CORE_THREAD_START, (void (*)(void))core_thread_start },
 #ifndef FIPS_MODULE
     { OSSL_FUNC_CORE_NEW_ERROR, (void (*)(void))core_new_error },
@@ -1074,16 +2246,26 @@ static const OSSL_DISPATCH core_dispatch_[] = {
     { OSSL_FUNC_CORE_CLEAR_LAST_ERROR_MARK,
       (void (*)(void))core_clear_last_error_mark },
     { OSSL_FUNC_CORE_POP_ERROR_TO_MARK, (void (*)(void))core_pop_error_to_mark },
-    { OSSL_FUNC_BIO_NEW_FILE, (void (*)(void))BIO_new_file },
-    { OSSL_FUNC_BIO_NEW_MEMBUF, (void (*)(void))BIO_new_mem_buf },
-    { OSSL_FUNC_BIO_READ_EX, (void (*)(void))BIO_read_ex },
-    { OSSL_FUNC_BIO_WRITE_EX, (void (*)(void))BIO_write_ex },
-    { OSSL_FUNC_BIO_GETS, (void (*)(void))BIO_gets },
-    { OSSL_FUNC_BIO_PUTS, (void (*)(void))BIO_puts },
-    { OSSL_FUNC_BIO_FREE, (void (*)(void))BIO_free },
-    { OSSL_FUNC_BIO_VPRINTF, (void (*)(void))BIO_vprintf },
+    { OSSL_FUNC_BIO_NEW_FILE, (void (*)(void))ossl_core_bio_new_file },
+    { OSSL_FUNC_BIO_NEW_MEMBUF, (void (*)(void))ossl_core_bio_new_mem_buf },
+    { OSSL_FUNC_BIO_READ_EX, (void (*)(void))ossl_core_bio_read_ex },
+    { OSSL_FUNC_BIO_WRITE_EX, (void (*)(void))ossl_core_bio_write_ex },
+    { OSSL_FUNC_BIO_GETS, (void (*)(void))ossl_core_bio_gets },
+    { OSSL_FUNC_BIO_PUTS, (void (*)(void))ossl_core_bio_puts },
+    { OSSL_FUNC_BIO_CTRL, (void (*)(void))ossl_core_bio_ctrl },
+    { OSSL_FUNC_BIO_UP_REF, (void (*)(void))ossl_core_bio_up_ref },
+    { OSSL_FUNC_BIO_FREE, (void (*)(void))ossl_core_bio_free },
+    { OSSL_FUNC_BIO_VPRINTF, (void (*)(void))ossl_core_bio_vprintf },
     { OSSL_FUNC_BIO_VSNPRINTF, (void (*)(void))BIO_vsnprintf },
-    { OSSL_FUNC_SELF_TEST_CB, (void (*)(void))OSSL_SELF_TEST_get_callback },
+    { OSSL_FUNC_SELF_TEST_CB, (void (*)(void))core_self_test_get_callback },
+    { OSSL_FUNC_GET_ENTROPY, (void (*)(void))rand_get_entropy },
+    { OSSL_FUNC_GET_USER_ENTROPY, (void (*)(void))rand_get_user_entropy },
+    { OSSL_FUNC_CLEANUP_ENTROPY, (void (*)(void))rand_cleanup_entropy },
+    { OSSL_FUNC_CLEANUP_USER_ENTROPY, (void (*)(void))rand_cleanup_user_entropy },
+    { OSSL_FUNC_GET_NONCE, (void (*)(void))rand_get_nonce },
+    { OSSL_FUNC_GET_USER_NONCE, (void (*)(void))rand_get_user_nonce },
+    { OSSL_FUNC_CLEANUP_NONCE, (void (*)(void))rand_cleanup_nonce },
+    { OSSL_FUNC_CLEANUP_USER_NONCE, (void (*)(void))rand_cleanup_user_nonce },
 #endif
     { OSSL_FUNC_CRYPTO_MALLOC, (void (*)(void))CRYPTO_malloc },
     { OSSL_FUNC_CRYPTO_ZALLOC, (void (*)(void))CRYPTO_zalloc },
@@ -1099,7 +2281,24 @@ static const OSSL_DISPATCH core_dispatch_[] = {
     { OSSL_FUNC_CRYPTO_SECURE_ALLOCATED,
         (void (*)(void))CRYPTO_secure_allocated },
     { OSSL_FUNC_OPENSSL_CLEANSE, (void (*)(void))OPENSSL_cleanse },
-
-    { 0, NULL }
+#ifndef FIPS_MODULE
+    { OSSL_FUNC_PROVIDER_REGISTER_CHILD_CB,
+        (void (*)(void))ossl_provider_register_child_cb },
+    { OSSL_FUNC_PROVIDER_DEREGISTER_CHILD_CB,
+        (void (*)(void))ossl_provider_deregister_child_cb },
+    { OSSL_FUNC_PROVIDER_NAME,
+        (void (*)(void))core_provider_get0_name },
+    { OSSL_FUNC_PROVIDER_GET0_PROVIDER_CTX,
+        (void (*)(void))core_provider_get0_provider_ctx },
+    { OSSL_FUNC_PROVIDER_GET0_DISPATCH,
+        (void (*)(void))core_provider_get0_dispatch },
+    { OSSL_FUNC_PROVIDER_UP_REF,
+        (void (*)(void))core_provider_up_ref_intern },
+    { OSSL_FUNC_PROVIDER_FREE,
+        (void (*)(void))core_provider_free_intern },
+    { OSSL_FUNC_CORE_OBJ_ADD_SIGID, (void (*)(void))core_obj_add_sigid },
+    { OSSL_FUNC_CORE_OBJ_CREATE, (void (*)(void))core_obj_create },
+#endif
+    OSSL_DISPATCH_END
 };
 static const OSSL_DISPATCH *core_dispatch = core_dispatch_;