Latest update

crypto/evp/evp_fetch.c

@@ -0,0 +1,197 @@
+/*
+ * Copyright 2019 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 <stddef.h>
+#include <openssl/ossl_typ.h>
+#include <openssl/evp.h>
+#include <openssl/core.h>
+#include "internal/cryptlib.h"
+#include "internal/thread_once.h"
+#include "internal/asn1_int.h"
+#include "internal/property.h"
+#include "internal/core.h"
+#include "internal/evp_int.h"    /* evp_locl.h needs it */
+#include "evp_locl.h"
+
+/* The OpenSSL library context index for the default method store */
+static int default_method_store_index = -1;
+
+static void default_method_store_free(void *vstore)
+{
+    ossl_method_store_free(vstore);
+}
+
+static void *default_method_store_new(void)
+{
+    return ossl_method_store_new();
+}
+
+
+static const OPENSSL_CTX_METHOD default_method_store_method = {
+    default_method_store_new,
+    default_method_store_free,
+};
+
+static int default_method_store_init(void)
+{
+    default_method_store_index =
+        openssl_ctx_new_index(&default_method_store_method);
+
+    return default_method_store_index != -1;
+}
+
+static CRYPTO_ONCE default_method_store_init_flag = CRYPTO_ONCE_STATIC_INIT;
+DEFINE_RUN_ONCE_STATIC(do_default_method_store_init)
+{
+    return OPENSSL_init_crypto(0, NULL)
+        && default_method_store_init();
+}
+
+/* Data to be passed through ossl_method_construct() */
+struct method_data_st {
+    const char *name;
+    int nid;
+    OSSL_METHOD_CONSTRUCT_METHOD *mcm;
+    void *(*method_from_dispatch)(int nid, const OSSL_DISPATCH *,
+                                  OSSL_PROVIDER *);
+    int (*refcnt_up_method)(void *method);
+    void (*destruct_method)(void *method);
+};
+
+/*
+ * Generic routines to fetch / create EVP methods with ossl_method_construct()
+ */
+static void *alloc_tmp_method_store(void)
+{
+    return ossl_method_store_new();
+}
+
+ static void dealloc_tmp_method_store(void *store)
+{
+    if (store != NULL)
+        ossl_method_store_free(store);
+}
+
+static
+struct OSSL_METHOD_STORE *get_default_method_store(OPENSSL_CTX *libctx)
+{
+    if (!RUN_ONCE(&default_method_store_init_flag,
+                  do_default_method_store_init))
+        return NULL;
+    return openssl_ctx_get_data(libctx, default_method_store_index);
+}
+
+static void *get_method_from_store(OPENSSL_CTX *libctx, void *store,
+                                   const char *propquery, void *data)
+{
+    struct method_data_st *methdata = data;
+    void *method = NULL;
+
+    if (store == NULL
+        && (store = get_default_method_store(libctx)) == NULL)
+        return NULL;
+
+    (void)ossl_method_store_fetch(store, methdata->nid, propquery, &method);
+
+    if (method != NULL
+        && !methdata->refcnt_up_method(method)) {
+        method = NULL;
+    }
+    return method;
+}
+
+static int put_method_in_store(OPENSSL_CTX *libctx, void *store,
+                               const char *propdef, void *method,
+                               void *data)
+{
+    struct method_data_st *methdata = data;
+
+    if (store == NULL
+        && (store = get_default_method_store(libctx)) == NULL)
+        return 0;
+
+    if (methdata->refcnt_up_method(method)
+        && ossl_method_store_add(store, methdata->nid, propdef, method,
+                                 methdata->destruct_method))
+        return 1;
+    return 0;
+}
+
+static void *construct_method(const OSSL_DISPATCH *fns, OSSL_PROVIDER *prov,
+                              void *data)
+{
+    struct method_data_st *methdata = data;
+    void *method = NULL;
+
+    if (methdata->nid == NID_undef) {
+        /* Create a new NID for that name on the fly */
+        ASN1_OBJECT tmpobj;
+
+        /* This is the same as OBJ_create() but without requiring a OID */
+        tmpobj.nid = OBJ_new_nid(1);
+        tmpobj.sn = tmpobj.ln = methdata->name;
+        tmpobj.flags = ASN1_OBJECT_FLAG_DYNAMIC;
+        tmpobj.length = 0;
+        tmpobj.data = NULL;
+
+        methdata->nid = OBJ_add_object(&tmpobj);
+    }
+
+    if (methdata->nid == NID_undef)
+        return NULL;
+
+    method = methdata->method_from_dispatch(methdata->nid, fns, prov);
+    if (method == NULL)
+        return NULL;
+    return method;
+}
+
+static void destruct_method(void *method, void *data)
+{
+    struct method_data_st *methdata = data;
+
+    methdata->destruct_method(method);
+}
+
+void *evp_generic_fetch(OPENSSL_CTX *libctx, int operation_id,
+                        const char *algorithm, const char *properties,
+                        void *(*new_method)(int nid, const OSSL_DISPATCH *fns,
+                                            OSSL_PROVIDER *prov),
+                        int (*upref_method)(void *),
+                        void (*free_method)(void *))
+{
+    int nid = OBJ_sn2nid(algorithm);
+    void *method = NULL;
+
+    if (nid == NID_undef
+        || !ossl_method_store_cache_get(NULL, nid, properties, &method)) {
+        OSSL_METHOD_CONSTRUCT_METHOD mcm = {
+            alloc_tmp_method_store,
+            dealloc_tmp_method_store,
+            get_method_from_store,
+            put_method_in_store,
+            construct_method,
+            destruct_method
+        };
+        struct method_data_st mcmdata;
+
+        mcmdata.nid = nid;
+        mcmdata.mcm = &mcm;
+        mcmdata.method_from_dispatch = new_method;
+        mcmdata.destruct_method = free_method;
+        mcmdata.refcnt_up_method = upref_method;
+        mcmdata.destruct_method = free_method;
+        method = ossl_method_construct(libctx, operation_id, algorithm,
+                                       properties, 0 /* !force_cache */,
+                                       &mcm, &mcmdata);
+        ossl_method_store_cache_set(NULL, nid, properties, method);
+    }
+
+    return method;
+}