1 files changed, 77 insertions, 0 deletions
diff --git a/providers/common/provider_seeding.c b/providers/common/provider_seeding.c
new file mode 100644
index 000000000000..0edbb8763066
--- /dev/null
+++ b/providers/common/provider_seeding.c
@@ -0,0 +1,77 @@
+/*
+ * Copyright 2020-2021 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/core_dispatch.h>
+#include "prov/seeding.h"
+
+static OSSL_FUNC_get_entropy_fn *c_get_entropy = NULL;
+static OSSL_FUNC_cleanup_entropy_fn *c_cleanup_entropy = NULL;
+static OSSL_FUNC_get_nonce_fn *c_get_nonce = NULL;
+static OSSL_FUNC_cleanup_nonce_fn *c_cleanup_nonce = NULL;
+
+int ossl_prov_seeding_from_dispatch(const OSSL_DISPATCH *fns)
+{
+    for (; fns->function_id != 0; fns++) {
+        /*
+         * We do not support the scenario of an application linked against
+         * multiple versions of libcrypto (e.g. one static and one dynamic), but
+         * sharing a single fips.so. We do a simple sanity check here.
+         */
+#define set_func(c, f) \
+    do { if (c == NULL) c = f; else if (c != f) return 0; } while (0)
+        switch (fns->function_id) {
+        case OSSL_FUNC_GET_ENTROPY:
+            set_func(c_get_entropy, OSSL_FUNC_get_entropy(fns));
+            break;
+        case OSSL_FUNC_CLEANUP_ENTROPY:
+            set_func(c_cleanup_entropy, OSSL_FUNC_cleanup_entropy(fns));
+            break;
+        case OSSL_FUNC_GET_NONCE:
+            set_func(c_get_nonce, OSSL_FUNC_get_nonce(fns));
+            break;
+        case OSSL_FUNC_CLEANUP_NONCE:
+            set_func(c_cleanup_nonce, OSSL_FUNC_cleanup_nonce(fns));
+            break;
+        }
+#undef set_func
+    }
+    return 1;
+}
+
+size_t ossl_prov_get_entropy(PROV_CTX *prov_ctx, unsigned char **pout,
+                             int entropy, size_t min_len, size_t max_len)
+{
+    if (c_get_entropy == NULL)
+        return 0;
+    return c_get_entropy(ossl_prov_ctx_get0_handle(prov_ctx),
+                         pout, entropy, min_len, max_len);
+}
+
+void ossl_prov_cleanup_entropy(PROV_CTX *prov_ctx, unsigned char *buf,
+                               size_t len)
+{
+    if (c_cleanup_entropy != NULL)
+        c_cleanup_entropy(ossl_prov_ctx_get0_handle(prov_ctx), buf, len);
+}
+
+size_t ossl_prov_get_nonce(PROV_CTX *prov_ctx, unsigned char **pout,
+                           size_t min_len, size_t max_len,
+                           const void *salt,size_t salt_len)
+{
+    if (c_get_nonce == NULL)
+        return 0;
+    return c_get_nonce(ossl_prov_ctx_get0_handle(prov_ctx), pout,
+                       min_len, max_len, salt, salt_len);
+}
+
+void ossl_prov_cleanup_nonce(PROV_CTX *prov_ctx, unsigned char *buf, size_t len)
+{
+    if (c_cleanup_nonce != NULL)
+        c_cleanup_nonce(ossl_prov_ctx_get0_handle(prov_ctx), buf, len);
+}