STORE: Add the base functions to support provider based loaders

This includes fixing a bug that could only be discovered when no
loaders were registered.

Reviewed-by: Shane Lontis <shane.lontis@oracle.com>
(Merged from https://github.com/openssl/openssl/pull/12512)

4 files changed, 486 insertions, 20 deletions

diff --git a/crypto/store/build.info b/crypto/store/build.info
index 7d882f313e..338c40efcc 100644
--- a/crypto/store/build.info
+++ b/crypto/store/build.info
@@ -1,4 +1,4 @@
 LIBS=../../libcrypto
 SOURCE[../../libcrypto]=\
         store_err.c store_init.c store_lib.c store_register.c store_strings.c \
-        loader_file.c
+        store_meth.c loader_file.c
diff --git a/crypto/store/store_local.h b/crypto/store/store_local.h
index 47cba87f86..15d4022856 100644
--- a/crypto/store/store_local.h
+++ b/crypto/store/store_local.h
@@ -7,7 +7,9 @@
  * https://www.openssl.org/source/license.html
  */
 
+#include <openssl/core_dispatch.h>
 #include "internal/thread_once.h"
+#include "internal/refcount.h"
 #include <openssl/dsa.h>
 #include <openssl/engine.h>
 #include <openssl/evp.h>
@@ -100,6 +102,7 @@ OSSL_STORE_LOADER *ossl_store_unregister_loader_int(const char *scheme);
 
 /* loader stuff */
 struct ossl_store_loader_st {
+    /* Legacy stuff */
     const char *scheme;
     ENGINE *engine;
     OSSL_STORE_open_fn open;
@@ -112,6 +115,23 @@ struct ossl_store_loader_st {
     OSSL_STORE_error_fn error;
     OSSL_STORE_close_fn close;
     OSSL_STORE_open_with_libctx_fn open_with_libctx;
+
+    /* Provider stuff */
+    OSSL_PROVIDER *prov;
+    int scheme_id;
+    const char *propdef;
+
+    CRYPTO_REF_COUNT refcnt;
+    CRYPTO_RWLOCK *lock;
+
+    OSSL_FUNC_store_open_fn *p_open;
+    OSSL_FUNC_store_attach_fn *p_attach;
+    OSSL_FUNC_store_settable_ctx_params_fn *p_settable_ctx_params;
+    OSSL_FUNC_store_set_ctx_params_fn *p_set_ctx_params;
+    OSSL_FUNC_store_load_fn *p_load;
+    OSSL_FUNC_store_eof_fn *p_eof;
+    OSSL_FUNC_store_close_fn *p_close;
+    OSSL_FUNC_store_export_object_fn *p_export_object;
 };
 DEFINE_LHASH_OF(OSSL_STORE_LOADER);
 
@@ -125,3 +145,22 @@ void ossl_store_destroy_loaders_int(void);
 
 int ossl_store_init_once(void);
 int ossl_store_file_loader_init(void);
+
+/*-
+ *  'file' scheme stuff
+ *  -------------------
+ */
+
+OSSL_STORE_LOADER_CTX *ossl_store_file_attach_pem_bio_int(BIO *bp);
+int ossl_store_file_detach_pem_bio_int(OSSL_STORE_LOADER_CTX *ctx);
+
+/*-
+ * Provider stuff
+ * -------------------
+ */
+OSSL_STORE_LOADER *ossl_store_loader_fetch(OPENSSL_CTX *libctx,
+                                           const char *scheme,
+                                           const char *properties);
+OSSL_STORE_LOADER *ossl_store_loader_fetch_by_number(OPENSSL_CTX *libctx,
+                                                     int scheme_id,
+                                                     const char *properties);
diff --git a/crypto/store/store_meth.c b/crypto/store/store_meth.c
new file mode 100644
index 0000000000..6af5ec14f2
--- /dev/null
+++ b/crypto/store/store_meth.c
@@ -0,0 +1,425 @@
+/*
+ * Copyright 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
+ */
+
+#include <openssl/store.h>
+#include <openssl/crypto.h>
+#include "internal/core.h"
+#include "internal/namemap.h"
+#include "internal/property.h"
+#include "internal/provider.h"
+#include "store_local.h"
+
+int OSSL_STORE_LOADER_up_ref(OSSL_STORE_LOADER *loader)
+{
+    int ref = 0;
+
+    if (loader->prov != NULL)
+        CRYPTO_UP_REF(&loader->refcnt, &ref, loader->lock);
+    return 1;
+}
+
+void OSSL_STORE_LOADER_free(OSSL_STORE_LOADER *loader)
+{
+    if (loader != NULL && loader->prov != NULL) {
+        int i;
+
+        CRYPTO_DOWN_REF(&loader->refcnt, &i, loader->lock);
+        if (i > 0)
+            return;
+        ossl_provider_free(loader->prov);
+        CRYPTO_THREAD_lock_free(loader->lock);
+    }
+    OPENSSL_free(loader);
+}
+
+/*
+ * OSSL_STORE_LOADER_new() expects the scheme as a constant string,
+ * which we currently don't have, so we need an alternative allocator.
+ */
+static OSSL_STORE_LOADER *new_loader(OSSL_PROVIDER *prov)
+{
+    OSSL_STORE_LOADER *loader;
+
+    if ((loader = OPENSSL_zalloc(sizeof(*loader))) == NULL
+        || (loader->lock = CRYPTO_THREAD_lock_new()) == NULL) {
+        OPENSSL_free(loader);
+        return NULL;
+    }
+    loader->prov = prov;
+    ossl_provider_up_ref(prov);
+    loader->refcnt = 1;
+
+    return loader;
+}
+
+static int up_ref_loader(void *method)
+{
+    return OSSL_STORE_LOADER_up_ref(method);
+}
+
+static void free_loader(void *method)
+{
+    OSSL_STORE_LOADER_free(method);
+}
+
+/* Permanent loader method store, constructor and destructor */
+static void loader_store_free(void *vstore)
+{
+    ossl_method_store_free(vstore);
+}
+
+static void *loader_store_new(OPENSSL_CTX *ctx)
+{
+    return ossl_method_store_new(ctx);
+}
+
+
+static const OPENSSL_CTX_METHOD loader_store_method = {
+    loader_store_new,
+    loader_store_free,
+};
+
+/* Data to be passed through ossl_method_construct() */
+struct loader_data_st {
+    OPENSSL_CTX *libctx;
+    OSSL_METHOD_CONSTRUCT_METHOD *mcm;
+    int scheme_id;               /* For get_loader_from_store() */
+    const char *scheme;          /* For get_loader_from_store() */
+    const char *propquery;       /* For get_loader_from_store() */
+};
+
+/*
+ * Generic routines to fetch / create OSSL_STORE methods with
+ * ossl_method_construct()
+ */
+
+/* Temporary loader method store, constructor and destructor */
+static void *alloc_tmp_loader_store(OPENSSL_CTX *ctx)
+{
+    return ossl_method_store_new(ctx);
+}
+
+ static void dealloc_tmp_loader_store(void *store)
+{
+    if (store != NULL)
+        ossl_method_store_free(store);
+}
+
+/* Get the permanent loader store */
+static OSSL_METHOD_STORE *get_loader_store(OPENSSL_CTX *libctx)
+{
+    return openssl_ctx_get_data(libctx, OPENSSL_CTX_STORE_LOADER_STORE_INDEX,
+                                &loader_store_method);
+}
+
+/* Get loader methods from a store, or put one in */
+static void *get_loader_from_store(OPENSSL_CTX *libctx, void *store,
+                                   void *data)
+{
+    struct loader_data_st *methdata = data;
+    void *method = NULL;
+    int id;
+
+    if ((id = methdata->scheme_id) == 0) {
+        OSSL_NAMEMAP *namemap = ossl_namemap_stored(libctx);
+
+        id = ossl_namemap_name2num(namemap, methdata->scheme);
+    }
+
+    if (store == NULL
+        && (store = get_loader_store(libctx)) == NULL)
+        return NULL;
+
+    if (!ossl_method_store_fetch(store, id, methdata->propquery, &method))
+        return NULL;
+    return method;
+}
+
+static int put_loader_in_store(OPENSSL_CTX *libctx, void *store,
+                               void *method, const OSSL_PROVIDER *prov,
+                               int operation_id, const char *scheme,
+                               const char *propdef, void *unused)
+{
+    OSSL_NAMEMAP *namemap;
+    int id;
+
+    if ((namemap = ossl_namemap_stored(libctx)) == NULL
+        || (id = ossl_namemap_name2num(namemap, scheme)) == 0)
+        return 0;
+
+    if (store == NULL && (store = get_loader_store(libctx)) == NULL)
+        return 0;
+
+    return ossl_method_store_add(store, prov, id, propdef, method,
+                                 up_ref_loader, free_loader);
+}
+
+static void *loader_from_dispatch(int scheme_id, const OSSL_ALGORITHM *algodef,
+                                  OSSL_PROVIDER *prov)
+{
+    OSSL_STORE_LOADER *loader = NULL;
+    const OSSL_DISPATCH *fns = algodef->implementation;
+
+    if ((loader = new_loader(prov)) == NULL)
+        return NULL;
+    loader->scheme_id = scheme_id;
+    loader->propdef = algodef->property_definition;
+
+    for (; fns->function_id != 0; fns++) {
+        switch (fns->function_id) {
+        case OSSL_FUNC_STORE_OPEN:
+            if (loader->p_open == NULL)
+                loader->p_open = OSSL_FUNC_store_open(fns);
+            break;
+        case OSSL_FUNC_STORE_ATTACH:
+            if (loader->p_attach == NULL)
+                loader->p_attach = OSSL_FUNC_store_attach(fns);
+            break;
+        case OSSL_FUNC_STORE_SETTABLE_CTX_PARAMS:
+            if (loader->p_settable_ctx_params == NULL)
+                loader->p_settable_ctx_params =
+                    OSSL_FUNC_store_settable_ctx_params(fns);
+            break;
+        case OSSL_FUNC_STORE_SET_CTX_PARAMS:
+            if (loader->p_set_ctx_params == NULL)
+                loader->p_set_ctx_params = OSSL_FUNC_store_set_ctx_params(fns);
+            break;
+        case OSSL_FUNC_STORE_LOAD:
+            if (loader->p_load == NULL)
+                loader->p_load = OSSL_FUNC_store_load(fns);
+            break;
+        case OSSL_FUNC_STORE_EOF:
+            if (loader->p_eof == NULL)
+                loader->p_eof = OSSL_FUNC_store_eof(fns);
+            break;
+        case OSSL_FUNC_STORE_CLOSE:
+            if (loader->p_close == NULL)
+                loader->p_close = OSSL_FUNC_store_close(fns);
+            break;
+        case OSSL_FUNC_STORE_EXPORT_OBJECT:
+            if (loader->p_export_object == NULL)
+                loader->p_export_object = OSSL_FUNC_store_export_object(fns);
+            break;
+        }
+    }
+
+    if ((loader->p_open == NULL && loader->p_attach == NULL)
+        || loader->p_load == NULL
+        || loader->p_eof == NULL
+        || loader->p_close == NULL) {
+        /* Only set_ctx_params is optionaal */
+        OSSL_STORE_LOADER_free(loader);
+        ERR_raise(ERR_LIB_OSSL_STORE, OSSL_STORE_R_LOADER_INCOMPLETE);
+        return NULL;
+    }
+    return loader;
+}
+
+/*
+ * The core fetching functionality passes the scheme of the implementation.
+ * This function is responsible to getting an identity number for them,
+ * then call loader_from_dispatch() with that identity number.
+ */
+static void *construct_loader(const OSSL_ALGORITHM *algodef,
+                              OSSL_PROVIDER *prov, void *unused)
+{
+    /*
+     * This function is only called if get_loader_from_store() returned
+     * NULL, so it's safe to say that of all the spots to create a new
+     * namemap entry, this is it.  Should the scheme already exist there, we
+     * know that ossl_namemap_add() will return its corresponding number.
+     */
+    OPENSSL_CTX *libctx = ossl_provider_library_context(prov);
+    OSSL_NAMEMAP *namemap = ossl_namemap_stored(libctx);
+    const char *scheme = algodef->algorithm_names;
+    int id = ossl_namemap_add_name(namemap, 0, scheme);
+    void *method = NULL;
+
+    if (id != 0)
+        method = loader_from_dispatch(id, algodef, prov);
+
+    return method;
+}
+
+/* Intermediary function to avoid ugly casts, used below */
+static void destruct_loader(void *method, void *data)
+{
+    OSSL_STORE_LOADER_free(method);
+}
+
+/* Fetching support.  Can fetch by numeric identity or by scheme */
+static OSSL_STORE_LOADER *inner_loader_fetch(OPENSSL_CTX *libctx,
+                                             int id, const char *scheme,
+                                             const char *properties)
+{
+    OSSL_METHOD_STORE *store = get_loader_store(libctx);
+    OSSL_NAMEMAP *namemap = ossl_namemap_stored(libctx);
+    void *method = NULL;
+
+    if (store == NULL || namemap == NULL)
+        return NULL;
+
+    /*
+     * If we have been passed neither a scheme_id or a scheme, we have an
+     * internal programming error.
+     */
+    if (!ossl_assert(id != 0 || scheme != NULL))
+        return NULL;
+
+    if (id == 0)
+        id = ossl_namemap_name2num(namemap, scheme);
+
+    if (id == 0
+        || !ossl_method_store_cache_get(store, id, properties, &method)) {
+        OSSL_METHOD_CONSTRUCT_METHOD mcm = {
+            alloc_tmp_loader_store,
+            dealloc_tmp_loader_store,
+            get_loader_from_store,
+            put_loader_in_store,
+            construct_loader,
+            destruct_loader
+        };
+        struct loader_data_st mcmdata;
+
+        mcmdata.libctx = libctx;
+        mcmdata.mcm = &mcm;
+        mcmdata.scheme_id = id;
+        mcmdata.scheme = scheme;
+        mcmdata.propquery = properties;
+        if ((method = ossl_method_construct(libctx, OSSL_OP_STORE,
+                                            0 /* !force_cache */,
+                                            &mcm, &mcmdata)) != NULL) {
+            /*
+             * If construction did create a method for us, we know that there
+             * is a correct scheme_id, since those have already been calculated
+             * in get_loader_from_store() and put_loader_in_store() above.
+             */
+            if (id == 0)
+                id = ossl_namemap_name2num(namemap, scheme);
+            ossl_method_store_cache_set(store, id, properties, method,
+                                        up_ref_loader, free_loader);
+        }
+    }
+
+    return method;
+}
+
+OSSL_STORE_LOADER *OSSL_STORE_LOADER_fetch(const char *scheme,
+                                           OPENSSL_CTX *libctx,
+                                           const char *properties)
+{
+    return inner_loader_fetch(libctx, 0, scheme, properties);
+}
+
+OSSL_STORE_LOADER *ossl_store_loader_fetch_by_number(OPENSSL_CTX *libctx,
+                                                     int scheme_id,
+                                                     const char *properties)
+{
+    return inner_loader_fetch(libctx, scheme_id, NULL, properties);
+}
+
+/*
+ * Library of basic method functions
+ */
+
+const OSSL_PROVIDER *OSSL_STORE_LOADER_provider(const OSSL_STORE_LOADER *loader)
+{
+    if (!ossl_assert(loader != NULL)) {
+        ERR_raise(ERR_LIB_OSSL_STORE, ERR_R_PASSED_NULL_PARAMETER);
+        return 0;
+    }
+
+    return loader->prov;
+}
+
+const char *OSSL_STORE_LOADER_properties(const OSSL_STORE_LOADER *loader)
+{
+    if (!ossl_assert(loader != NULL)) {
+        ERR_raise(ERR_LIB_OSSL_STORE, ERR_R_PASSED_NULL_PARAMETER);
+        return 0;
+    }
+
+    return loader->propdef;
+}
+
+int OSSL_STORE_LOADER_number(const OSSL_STORE_LOADER *loader)
+{
+    if (!ossl_assert(loader != NULL)) {
+        ERR_raise(ERR_LIB_OSSL_STORE, ERR_R_PASSED_NULL_PARAMETER);
+        return 0;
+    }
+
+    return loader->scheme_id;
+}
+
+int OSSL_STORE_LOADER_is_a(const OSSL_STORE_LOADER *loader, const char *name)
+{
+    if (loader->prov != NULL) {
+        OPENSSL_CTX *libctx = ossl_provider_library_context(loader->prov);
+        OSSL_NAMEMAP *namemap = ossl_namemap_stored(libctx);
+
+        return ossl_namemap_name2num(namemap, name) == loader->scheme_id;
+    }
+    return 0;
+}
+
+struct loader_do_all_data_st {
+    void (*user_fn)(void *method, void *arg);
+    void *user_arg;
+};
+
+static void loader_do_one(OSSL_PROVIDER *provider,
+                          const OSSL_ALGORITHM *algodef,
+                          int no_store, void *vdata)
+{
+    struct loader_do_all_data_st *data = vdata;
+    OPENSSL_CTX *libctx = ossl_provider_library_context(provider);
+    OSSL_NAMEMAP *namemap = ossl_namemap_stored(libctx);
+    const char *name = algodef->algorithm_names;
+    int id = ossl_namemap_add_name(namemap, 0, name);
+    void *method = NULL;
+
+    if (id != 0)
+        method =
+            loader_from_dispatch(id, algodef, provider);
+
+    if (method != NULL) {
+        data->user_fn(method, data->user_arg);
+        OSSL_STORE_LOADER_free(method);
+    }
+}
+
+void OSSL_STORE_LOADER_do_all_provided(OPENSSL_CTX *libctx,
+                                       void (*fn)(OSSL_STORE_LOADER *loader,
+                                                  void *arg),
+                                       void *arg)
+{
+    struct loader_do_all_data_st data;
+
+    data.user_fn = (void (*)(void *, void *))fn;
+    data.user_arg = arg;
+    ossl_algorithm_do_all(libctx, OSSL_OP_STORE, NULL,
+                          NULL, loader_do_one, NULL,
+                          &data);
+}
+
+void OSSL_STORE_LOADER_names_do_all(const OSSL_STORE_LOADER *loader,
+                                    void (*fn)(const char *name, void *data),
+                                    void *data)
+{
+    if (loader == NULL)
+        return;
+
+    if (loader->prov != NULL) {
+        OPENSSL_CTX *libctx = ossl_provider_library_context(loader->prov);
+        OSSL_NAMEMAP *namemap = ossl_namemap_stored(libctx);
+
+        ossl_namemap_doall_names(namemap, loader->scheme_id, fn, data);
+    }
+}
diff --git a/crypto/store/store_register.c b/crypto/store/store_register.c
index f5106f0077..94865ee9e0 100644
--- a/crypto/store/store_register.c
+++ b/crypto/store/store_register.c
@@ -135,11 +135,6 @@ int OSSL_STORE_LOADER_set_close(OSSL_STORE_LOADER *loader,
     return 1;
 }
 
-void OSSL_STORE_LOADER_free(OSSL_STORE_LOADER *loader)
-{
-    OPENSSL_free(loader);
-}
-
 /*
  *  Functions for registering OSSL_STORE_LOADERs
  */
@@ -157,6 +152,14 @@ static int store_loader_cmp(const OSSL_STORE_LOADER *a,
 }
 
 static LHASH_OF(OSSL_STORE_LOADER) *loader_register = NULL;
+static int ossl_store_register_init(void)
+{
+    if (loader_register == NULL) {
+        loader_register = lh_OSSL_STORE_LOADER_new(store_loader_hash,
+                                                   store_loader_cmp);
+    }
+    return loader_register != NULL;
+}
 
 int ossl_store_register_loader_int(OSSL_STORE_LOADER *loader)
 {
@@ -197,12 +200,7 @@ int ossl_store_register_loader_int(OSSL_STORE_LOADER *loader)
     }
     CRYPTO_THREAD_write_lock(registry_lock);
 
-    if (loader_register == NULL) {
-        loader_register = lh_OSSL_STORE_LOADER_new(store_loader_hash,
-                                                   store_loader_cmp);
-    }
-
-    if (loader_register != NULL
+    if (ossl_store_register_init()
         && (lh_OSSL_STORE_LOADER_insert(loader_register, loader) != NULL
             || lh_OSSL_STORE_LOADER_error(loader_register) == 0))
         ok = 1;
@@ -240,9 +238,11 @@ const OSSL_STORE_LOADER *ossl_store_get0_loader_int(const char *scheme)
     }
     CRYPTO_THREAD_write_lock(registry_lock);
 
-    loader = lh_OSSL_STORE_LOADER_retrieve(loader_register, &template);
-
-    if (loader == NULL) {
+    if (!ossl_store_register_init()) {
+        OSSL_STOREerr(OSSL_STORE_F_OSSL_STORE_GET0_LOADER_INT,
+                      ERR_R_INTERNAL_ERROR);
+    } else if ((loader = lh_OSSL_STORE_LOADER_retrieve(loader_register,
+                                                       &template)) == NULL) {
         OSSL_STOREerr(OSSL_STORE_F_OSSL_STORE_GET0_LOADER_INT,
                       OSSL_STORE_R_UNREGISTERED_SCHEME);
         ERR_add_error_data(2, "scheme=", scheme);
@@ -271,9 +271,11 @@ OSSL_STORE_LOADER *ossl_store_unregister_loader_int(const char *scheme)
     }
     CRYPTO_THREAD_write_lock(registry_lock);
 
-    loader = lh_OSSL_STORE_LOADER_delete(loader_register, &template);
-
-    if (loader == NULL) {
+    if (!ossl_store_register_init()) {
+        OSSL_STOREerr(OSSL_STORE_F_OSSL_STORE_UNREGISTER_LOADER_INT,
+                      ERR_R_INTERNAL_ERROR);
+    } else if ((loader = lh_OSSL_STORE_LOADER_delete(loader_register,
+                                                     &template)) == NULL) {
         OSSL_STOREerr(OSSL_STORE_F_OSSL_STORE_UNREGISTER_LOADER_INT,
                       OSSL_STORE_R_UNREGISTERED_SCHEME);
         ERR_add_error_data(2, "scheme=", scheme);
@@ -292,7 +294,6 @@ OSSL_STORE_LOADER *OSSL_STORE_unregister_loader(const char *scheme)
 
 void ossl_store_destroy_loaders_int(void)
 {
-    assert(lh_OSSL_STORE_LOADER_num_items(loader_register) == 0);
     lh_OSSL_STORE_LOADER_free(loader_register);
     loader_register = NULL;
     CRYPTO_THREAD_lock_free(registry_lock);
@@ -308,6 +309,7 @@ int OSSL_STORE_do_all_loaders(void (*do_function) (const OSSL_STORE_LOADER
                                                    *loader, void *do_arg),
                               void *do_arg)
 {
-    lh_OSSL_STORE_LOADER_doall_void(loader_register, do_function, do_arg);
+    if (ossl_store_register_init())
+        lh_OSSL_STORE_LOADER_doall_void(loader_register, do_function, do_arg);
     return 1;
 }