EVP: Implement support for key downgrading in backends

[openssl.git] / crypto / ffc / ffc_backend.c

diff --git a/crypto/ffc/ffc_backend.c b/crypto/ffc/ffc_backend.c
new file mode 100644 (file)
index 0000000..cde9e43
--- /dev/null
+++ b/crypto/ffc/ffc_backend.c
@@ -0,0 +1,44 @@
+/*
+ * 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/core_names.h>
+#include "internal/ffc.h"
+
+/*
+ * The intention with the "backend" source file is to offer backend support
+ * for legacy backends (EVP_PKEY_ASN1_METHOD and EVP_PKEY_METHOD) and provider
+ * implementations alike.
+ */
+
+int ffc_fromdata(FFC_PARAMS *ffc, const OSSL_PARAM params[])
+{
+    const OSSL_PARAM *param_p, *param_q, *param_g;
+    BIGNUM *p = NULL, *q = NULL, *g = NULL;
+
+    if (ffc == NULL)
+        return 0;
+
+    param_p = OSSL_PARAM_locate_const(params, OSSL_PKEY_PARAM_FFC_P);
+    param_q = OSSL_PARAM_locate_const(params, OSSL_PKEY_PARAM_FFC_Q);
+    param_g = OSSL_PARAM_locate_const(params, OSSL_PKEY_PARAM_FFC_G);
+
+    if ((param_p != NULL && !OSSL_PARAM_get_BN(param_p, &p))
+        || (param_q != NULL && !OSSL_PARAM_get_BN(param_q, &q))
+        || (param_g != NULL && !OSSL_PARAM_get_BN(param_g, &g)))
+        goto err;
+
+    ffc_params_set0_pqg(ffc, p, q, g);
+    return 1;
+
+ err:
+    BN_free(p);
+    BN_free(q);
+    BN_free(g);
+    return 0;
+}