commit ba5b5d67aa10e3c7dc5d2136efc226368df1b262
author Gilles Peskine <Gilles.Peskine@arm.com> Wed Jun 21 18:24:04 2023 +0200
committer Gilles Peskine <Gilles.Peskine@arm.com> Fri Dec 22 21:30:03 2023 +0100
tree 16ed293972eeb6fc8b5f3c90c71013fa97f5e327
parent e6886102ef23ad38dd8e3ac8df1e26f34c22c75e

Support partial export from mbedtls_ecp_keypair

Sometimes you don't need to have all the parts of a key pair object. Relax
the behavior of mbedtls_ecp_keypair so that you can extract just the parts
that you need.

Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>

library/ecp.c

diff --git a/library/ecp.c b/library/ecp.c
index 351e9e8..b4da3c5 100644
--- a/library/ecp.c
+++ b/library/ecp.c
@@ -3371,15 +3371,15 @@
 {
     int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
 
-    if ((ret = mbedtls_ecp_group_copy(grp, &key->grp)) != 0) {
+    if (grp != NULL && (ret = mbedtls_ecp_group_copy(grp, &key->grp)) != 0) {
         return ret;
     }
 
-    if ((ret = mbedtls_mpi_copy(d, &key->d)) != 0) {
+    if (d != NULL && (ret = mbedtls_mpi_copy(d, &key->d)) != 0) {
         return ret;
     }
 
-    if ((ret = mbedtls_ecp_copy(Q, &key->Q)) != 0) {
+    if (Q != NULL && (ret = mbedtls_ecp_copy(Q, &key->Q)) != 0) {
         return ret;
     }