[PATCH 1/1] lib: rsa: fix padding_pss_verify

[Heinrich Schuchardt]

Check the that the hash length is shorter than the message length. This
avoids:

    ./tools/../lib/rsa/rsa-verify.c:275:11: warning:
    ‘*db’ may be used uninitialized [-Wmaybe-uninitialized]
      275 |         db[0] &= 0xff >> leftmost_bits;

Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt at canonical.com>
---
 lib/rsa/rsa-verify.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/lib/rsa/rsa-verify.c b/lib/rsa/rsa-verify.c
index 1d95cfbdee..255f99be24 100644
--- a/lib/rsa/rsa-verify.c
+++ b/lib/rsa/rsa-verify.c
@@ -234,6 +234,9 @@ int padding_pss_verify(struct image_sign_info *info,
 	uint8_t leftmost_mask;
 	struct checksum_algo *checksum = info->checksum;
 
+	if (db_len <= 0)
+		return 1;
+
 	/* first, allocate everything */
 	db_mask = malloc(db_len);
 	db = malloc(db_len);
-- 
2.37.2