From 405ec94ea2b6663e5fc4267530bec85e3f56e4c3 Mon Sep 17 00:00:00 2001
From: JonathanWitthoeft <jonw@gridconnect.com>
Date: Wed, 26 Apr 2023 10:24:12 -0500
Subject: [PATCH] Bug Fix: mbedtls_ecdsa_verify_restartable fails with
 ECDSA_SIGN_ALT

When ECDSA_SIGN_ALT but not ECDSA_VERIFY_ALT, mbedtls_ecdsa_can_do was not being defined causing mbedtls_ecdsa_verify_restartable to always fail

Signed-off-by: JonathanWitthoeft <jonw@gridconnect.com>
---
 library/ecdsa.c | 31 ++++++++++++++++++-------------
 1 file changed, 18 insertions(+), 13 deletions(-)

diff --git a/library/ecdsa.c b/library/ecdsa.c
index eb3c30319..618c7b059 100644
--- a/library/ecdsa.c
+++ b/library/ecdsa.c
@@ -234,6 +234,24 @@ cleanup:
 }
 #endif /* ECDSA_DETERMINISTIC || !ECDSA_SIGN_ALT || !ECDSA_VERIFY_ALT */
 
+#if !defined(MBEDTLS_ECDSA_SIGN_ALT)     || \
+    !defined(MBEDTLS_ECDSA_VERIFY_ALT)
+
+int mbedtls_ecdsa_can_do(mbedtls_ecp_group_id gid)
+{
+    switch (gid) {
+#ifdef MBEDTLS_ECP_DP_CURVE25519_ENABLED
+        case MBEDTLS_ECP_DP_CURVE25519: return 0;
+#endif
+#ifdef MBEDTLS_ECP_DP_CURVE448_ENABLED
+        case MBEDTLS_ECP_DP_CURVE448: return 0;
+#endif
+        default: return 1;
+    }
+}
+
+#endif /* !ECDSA_SIGN_ALT || !ECDSA_VERIFY_ALT */
+
 #if !defined(MBEDTLS_ECDSA_SIGN_ALT)
 /*
  * Compute ECDSA signature of a hashed message (SEC1 4.1.3)
@@ -373,19 +391,6 @@ cleanup:
     return ret;
 }
 
-int mbedtls_ecdsa_can_do(mbedtls_ecp_group_id gid)
-{
-    switch (gid) {
-#ifdef MBEDTLS_ECP_DP_CURVE25519_ENABLED
-        case MBEDTLS_ECP_DP_CURVE25519: return 0;
-#endif
-#ifdef MBEDTLS_ECP_DP_CURVE448_ENABLED
-        case MBEDTLS_ECP_DP_CURVE448: return 0;
-#endif
-        default: return 1;
-    }
-}
-
 /*
  * Compute ECDSA signature of a hashed message
  */