1 files changed, 62 insertions, 0 deletions
diff --git a/crypto/ec/ecx_backend.c b/crypto/ec/ecx_backend.c
new file mode 100644
index 0000000000..e613337029
--- /dev/null
+++ b/crypto/ec/ecx_backend.c
@@ -0,0 +1,62 @@
+/*
+ * 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 <openssl/params.h>
+#include "crypto/ecx.h"
+#include "ecx_backend.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 ecx_key_fromdata(ECX_KEY *ecx, const OSSL_PARAM params[],
+                     int include_private)
+{
+    size_t privkeylen = 0, pubkeylen;
+    const OSSL_PARAM *param_priv_key = NULL, *param_pub_key;
+    unsigned char *pubkey;
+
+    if (ecx == NULL)
+        return 0;
+
+    param_pub_key = OSSL_PARAM_locate_const(params, OSSL_PKEY_PARAM_PUB_KEY);
+    if (include_private)
+        param_priv_key =
+            OSSL_PARAM_locate_const(params, OSSL_PKEY_PARAM_PRIV_KEY);
+    /*
+     * If a private key is present then a public key must also be present.
+     * Alternatively we've just got a public key.
+     */
+    if (param_pub_key == NULL)
+        return 0;
+
+    if (param_priv_key != NULL
+        && !OSSL_PARAM_get_octet_string(param_priv_key,
+                                        (void **)&ecx->privkey, ecx->keylen,
+                                        &privkeylen))
+        return 0;
+
+    pubkey = ecx->pubkey;
+    if (!OSSL_PARAM_get_octet_string(param_pub_key,
+                                     (void **)&pubkey,
+                                     sizeof(ecx->pubkey), &pubkeylen))
+        return 0;
+
+    if (pubkeylen != ecx->keylen
+        || (param_priv_key != NULL && privkeylen != ecx->keylen))
+        return 0;
+
+    ecx->haspubkey = 1;
+
+    return 1;
+}
+