From: Andrej Shadura Date: Thu, 30 Jan 2020 17:31:36 +0100 Subject: Check the hash algorithm before (possibly failing to) malloc malloc only accepts unsigned sizes, so failing to catch a negative size as an errorcode will result in a malloc call with an enormous value, leading to an allocation failure and a nonsensical error message. Signed-off-by: Andrej Shadura --- code/cst/code/front_end/src/acst.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/code/cst/code/front_end/src/acst.c b/code/cst/code/front_end/src/acst.c index e382673..3f780ab 100644 --- a/code/cst/code/front_end/src/acst.c +++ b/code/cst/code/front_end/src/acst.c @@ -788,16 +788,17 @@ void encrypt_images(ahab_data_t *ahab_data, uint8_t hash_type = ahab_container_image_get_hash(image); int32_t hash_size = ahab_get_hash_size_by_sha_type(hash_type); + + if (hash_size < 0) { + error("Unsupported hash algorithm for image integrity"); + } + uint8_t *hash = malloc(hash_size); if (NULL == hash) { error("Cannot allocate memory for the hash value of the plaintext"); } - if (hash_size < 0) { - error("Unsupported hash algorithm for image integrity"); - } - /* Retrieve image data */ offsets_t offsets = {