[PATCH] ecdsa: fix segfault in mkimage when "-r" option is not set

[Lucas Dietrich]

Fix a segmentation fault in the ECDSA signing logic of `mkimage`
that occurs when the "-r" option is not specified.

This reproduces the logic in `lib/rsa/rsa-sign.c` by checking if
`info->require_keys` is non-null before passing it to
`fdt_setprop_string()`.

Signed-off-by: Lucas Dietrich <lucas.dietrich.git at proton.me>
---
 lib/ecdsa/ecdsa-libcrypto.c | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/lib/ecdsa/ecdsa-libcrypto.c b/lib/ecdsa/ecdsa-libcrypto.c
index f0095e9dbcf..f48df2b870f 100644
--- a/lib/ecdsa/ecdsa-libcrypto.c
+++ b/lib/ecdsa/ecdsa-libcrypto.c
@@ -345,10 +345,12 @@ static int do_add(struct signer *ctx, void *fdt, const char *key_node_name,
 	if (ret < 0)
 		return ret;
 
-	ret = fdt_setprop_string(fdt, key_node, FIT_KEY_REQUIRED,
-				 info->require_keys);
-	if (ret < 0)
-		return ret;
+	if (info->require_keys) {
+		ret = fdt_setprop_string(fdt, key_node, FIT_KEY_REQUIRED,
+					 info->require_keys);
+		if (ret < 0)
+			return ret;
+	}
 
 	return key_node;
 }
-- 
2.39.5