From 182c2e98365c20c5e0e8bca3180ec74d26d1d17f Mon Sep 17 00:00:00 2001
From: Gilles Peskine <Gilles.Peskine@arm.com>
Date: Fri, 19 Oct 2018 11:33:51 +0200
Subject: [PATCH] psa_constant_names: fix display for truncated unknown
 MAC/AEAD algorithm

---
 scripts/generate_psa_constants.py | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/scripts/generate_psa_constants.py b/scripts/generate_psa_constants.py
index 3e4e88b77..bcda282ce 100755
--- a/scripts/generate_psa_constants.py
+++ b/scripts/generate_psa_constants.py
@@ -62,7 +62,10 @@ static int psa_snprint_algorithm(char *buffer, size_t buffer_size,
         }
     } else if (PSA_ALG_IS_AEAD(alg)) {
         core_alg = PSA_ALG_AEAD_WITH_DEFAULT_TAG_LENGTH(alg);
-        if (core_alg != alg) {
+        if (core_alg == 0) {
+            /* For unkonwn AEAD algorithms, there is no "default tag length". */
+            core_alg = alg;
+        } else if (core_alg != alg) {
             append(&buffer, buffer_size, &required_size,
                    "PSA_ALG_AEAD_WITH_TAG_LENGTH(", 29);
             length_modifier = PSA_AEAD_TAG_LENGTH(alg);
@@ -73,7 +76,7 @@ static int psa_snprint_algorithm(char *buffer, size_t buffer_size,
     default:
         %(algorithm_code)s{
             append_integer(&buffer, buffer_size, &required_size,
-                           "0x%%08lx", (unsigned long) alg);
+                           "0x%%08lx", (unsigned long) core_alg);
         }
         break;
     }