Replumbing: New public API to load or add providers

Adding a provider means creating an internal provier object and adding
it to the store.  This allows the addition of built in providers, be it
in the OpenSSL libraries or in any application.

"Loading" a provider is defined broadly.  A built in provider is already
"loaded" in essence and only needs activating, while a provider in a
dynamically loadable module requires actually loading the module itself.
In this API, "loading" a provider does both.

Reviewed-by: Matt Caswell <matt@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/8287)

1 files changed, 70 insertions, 0 deletions

diff --git a/crypto/provider.c b/crypto/provider.c
new file mode 100644
index 0000000000..823d5dd585
--- /dev/null
+++ b/crypto/provider.c
@@ -0,0 +1,70 @@
+/*
+ * 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 <openssl/err.h>
+#include <openssl/cryptoerr.h>
+#include <openssl/provider.h>
+#include "internal/provider.h"
+
+OSSL_PROVIDER *OSSL_PROVIDER_load(OPENSSL_CTX *libctx, const char *name)
+{
+    OSSL_PROVIDER *prov = NULL;
+
+    /* Find it or create it */
+    if ((prov = ossl_provider_find(libctx, name)) == NULL
+        && (prov = ossl_provider_new(libctx, name, NULL)) == NULL)
+        return NULL;
+
+    if (!ossl_provider_activate(prov)) {
+        ossl_provider_free(prov);
+        return NULL;
+    }
+
+    return prov;
+}
+
+int OSSL_PROVIDER_unload(OSSL_PROVIDER *prov)
+{
+    ossl_provider_free(prov);
+    return 1;
+}
+
+const OSSL_ITEM *OSSL_PROVIDER_get_param_types(OSSL_PROVIDER *prov)
+{
+    return ossl_provider_get_param_types(prov);
+}
+
+int OSSL_PROVIDER_get_params(OSSL_PROVIDER *prov, const OSSL_PARAM params[])
+{
+    return ossl_provider_get_params(prov, params);
+}
+
+int OSSL_PROVIDER_add_builtin(OPENSSL_CTX *libctx, const char *name,
+                              OSSL_provider_init_fn *init_fn)
+{
+    OSSL_PROVIDER *prov = NULL;
+
+    if (name == NULL || init_fn == NULL) {
+        CRYPTOerr(CRYPTO_F_OSSL_PROVIDER_ADD_BUILTIN,
+                  ERR_R_PASSED_NULL_PARAMETER);
+        return 0;
+    }
+
+    /* Create it */
+    if ((prov = ossl_provider_new(libctx, name, init_fn)) == NULL)
+        return 0;
+
+    /*
+     * It's safely stored in the internal store at this point,
+     * free the returned extra reference
+     */
+    ossl_provider_free(prov);
+
+    return 1;
+}