Check for output allocation before randomising
Signed-off-by: Thomas Daubney <thomas.daubney@arm.com>
diff --git a/library/psa_crypto.c b/library/psa_crypto.c
index 994f9a9..964ae51 100644
--- a/library/psa_crypto.c
+++ b/library/psa_crypto.c
@@ -5298,6 +5298,7 @@
size_t expected_length;
LOCAL_INPUT_DECLARE(peer_key_external, peer_key);
LOCAL_OUTPUT_DECLARE(output_external, output);
+ LOCAL_OUTPUT_ALLOC(output_external, output_size, output);
if (!PSA_ALG_IS_KEY_AGREEMENT(alg)) {
status = PSA_ERROR_INVALID_ARGUMENT;
@@ -5325,23 +5326,29 @@
}
LOCAL_INPUT_ALLOC(peer_key_external, peer_key_length, peer_key);
- LOCAL_OUTPUT_ALLOC(output_external, output_size, output);
status = psa_key_agreement_raw_internal(alg, slot,
peer_key, peer_key_length,
output, output_size,
output_length);
exit:
- if (status != PSA_SUCCESS && output != NULL) {
- /* If an error happens and is not handled properly, the output
- * may be used as a key to protect sensitive data. Arrange for such
- * a key to be random, which is likely to result in decryption or
- * verification errors. This is better than filling the buffer with
- * some constant data such as zeros, which would result in the data
- * being protected with a reproducible, easily knowable key.
- */
- psa_generate_random(output, output_size);
- *output_length = output_size;
+ /* Check for successful allocation of output. */
+ if (output != NULL && status != PSA_ERROR_INSUFFICIENT_MEMORY) {
+ /* output allocated. */
+ if (status != PSA_SUCCESS) {
+ /* If an error happens and is not handled properly, the output
+ * may be used as a key to protect sensitive data. Arrange for such
+ * a key to be random, which is likely to result in decryption or
+ * verification errors. This is better than filling the buffer with
+ * some constant data such as zeros, which would result in the data
+ * being protected with a reproducible, easily knowable key.
+ */
+ psa_generate_random(output, output_size);
+ *output_length = output_size;
+ }
+ } else {
+ /* output allocation failed. */
+ *output_length = 0;
}
unlock_status = psa_unlock_key_slot(slot);