[PATCH v2 2/4] lib: ecdsa: Create device tree node automatically

[Chia-Wei Wang <chiawei_wang@aspeedtech.com>]

Both the signature and the public key are stored as DTS nodes
in the FIT image and SPL/U-Boot DTBs.

Like the RSA signing & verification do, this patch either creates
the nodes or overwirte the content automatically.

Signed-off-by: Chia-Wei Wang <chiawei_wang@aspeedtech.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
---
 lib/ecdsa/ecdsa-libcrypto.c | 25 ++++++++++++++++++-------
 1 file changed, 18 insertions(+), 7 deletions(-)

diff --git a/lib/ecdsa/ecdsa-libcrypto.c b/lib/ecdsa/ecdsa-libcrypto.c
index 5fa9be10b4b..774cc946c7b 100644
--- a/lib/ecdsa/ecdsa-libcrypto.c
+++ b/lib/ecdsa/ecdsa-libcrypto.c
@@ -281,15 +281,26 @@ static int do_add(struct signer *ctx, void *fdt, const char *key_node_name)
 	BIGNUM *x, *y;
 
 	signature_node = fdt_subnode_offset(fdt, 0, FIT_SIG_NODENAME);
-	if (signature_node < 0) {
-		fprintf(stderr, "Could not find 'signature node: %s\n",
-			fdt_strerror(signature_node));
-		return signature_node;
+	if (signature_node == -FDT_ERR_NOTFOUND) {
+		signature_node = fdt_add_subnode(fdt, 0, FIT_SIG_NODENAME);
+		if (signature_node < 0) {
+			fprintf(stderr, "Could not add 'signature' node: %s\n",
+				fdt_strerror(signature_node));
+			return signature_node;
+		}
 	}
 
-	key_node = fdt_add_subnode(fdt, signature_node, key_node_name);
-	if (key_node < 0) {
-		fprintf(stderr, "Could not create '%s' node: %s\n",
+	/* Either create or overwrite the named key node */
+	key_node = fdt_subnode_offset(fdt, signature_node, key_node_name);
+	if (key_node == -FDT_ERR_NOTFOUND) {
+		key_node = fdt_add_subnode(fdt, signature_node, key_node_name);
+		if (key_node < 0) {
+			fprintf(stderr, "Could not create '%s' node: %s\n",
+				key_node_name, fdt_strerror(key_node));
+			return key_node;
+		}
+	} else if (key_node < 0) {
+		fprintf(stderr, "cannot select '%s' node: %s\n",
 			key_node_name, fdt_strerror(key_node));
 		return key_node;
 	}
-- 
2.25.1