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 <[email protected]>

library/ecdsa.c

@@ -240,6 +240,24 @@ static int derive_mpi(const mbedtls_ecp_group *grp, mbedtls_mpi *x,
 }
 #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)
@@ -379,19 +397,6 @@ static int ecdsa_sign_restartable(mbedtls_ecp_group *grp,
     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
  */