Import mbedtls-3.6.0

Imports Mbed TLS 3.6.0 from https://github.com/Mbed-TLS/mbedtls.git
tags mbedtls-3.6.0, v3.6.0

Files that are not needed are removed:

cd lib/libmbedtls
rm -rf mbedtls
cp -R path/to/mbedtls-3.6.0/mbedtls .
cd mbedtls
rm CMakeLists.txt DartConfiguration.tcl Makefile
rm .gitignore .travis.yml .pylintrc .globalrc .mypy.ini BRANCHES.md
rm include/.gitignore include/CMakeLists.txt library/.gitignore
rm library/CMakeLists.txt library/Makefile
rm -r cmake
rm -rf .git .github doxygen configs programs scripts tests visualc
rm -rf 3rdparty ChangeLog.d docs pkgconfig .gitmodules .readthedocs.yaml
rm library/mps_*
cd ..
git add mbedtls

This time we leave library/psa_* present to enable TLS 1.3 features.

This is a complete overwrite of previous code so earlier changes in the
previous branch import/mbedtls-3.4.0 will be added on top of this commit.

Signed-off-by: Tom Van Eyck <tom.vaneyck@kuleuven.be>
Acked-by: Jens Wiklander <jens.wiklander@linaro.org>
diff --git a/lib/libmbedtls/mbedtls/library/asn1parse.c b/lib/libmbedtls/mbedtls/library/asn1parse.c
index d257ef4..e33fdf7 100644
--- a/lib/libmbedtls/mbedtls/library/asn1parse.c
+++ b/lib/libmbedtls/mbedtls/library/asn1parse.c
@@ -2,24 +2,13 @@
  *  Generic ASN.1 parsing
  *
  *  Copyright The Mbed TLS Contributors
- *  SPDX-License-Identifier: Apache-2.0
- *
- *  Licensed under the Apache License, Version 2.0 (the "License"); you may
- *  not use this file except in compliance with the License.
- *  You may obtain a copy of the License at
- *
- *  http://www.apache.org/licenses/LICENSE-2.0
- *
- *  Unless required by applicable law or agreed to in writing, software
- *  distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
- *  WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- *  See the License for the specific language governing permissions and
- *  limitations under the License.
+ *  SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later
  */
 
 #include "common.h"
 
-#if defined(MBEDTLS_ASN1_PARSE_C)
+#if defined(MBEDTLS_ASN1_PARSE_C) || defined(MBEDTLS_X509_CREATE_C) || \
+    defined(MBEDTLS_PSA_UTIL_HAVE_ECDSA)
 
 #include "mbedtls/asn1.h"
 #include "mbedtls/platform_util.h"
@@ -47,47 +36,18 @@
     if ((**p & 0x80) == 0) {
         *len = *(*p)++;
     } else {
-        switch (**p & 0x7F) {
-            case 1:
-                if ((end - *p) < 2) {
-                    return MBEDTLS_ERR_ASN1_OUT_OF_DATA;
-                }
-
-                *len = (*p)[1];
-                (*p) += 2;
-                break;
-
-            case 2:
-                if ((end - *p) < 3) {
-                    return MBEDTLS_ERR_ASN1_OUT_OF_DATA;
-                }
-
-                *len = ((size_t) (*p)[1] << 8) | (*p)[2];
-                (*p) += 3;
-                break;
-
-            case 3:
-                if ((end - *p) < 4) {
-                    return MBEDTLS_ERR_ASN1_OUT_OF_DATA;
-                }
-
-                *len = ((size_t) (*p)[1] << 16) |
-                       ((size_t) (*p)[2] << 8) | (*p)[3];
-                (*p) += 4;
-                break;
-
-            case 4:
-                if ((end - *p) < 5) {
-                    return MBEDTLS_ERR_ASN1_OUT_OF_DATA;
-                }
-
-                *len = ((size_t) (*p)[1] << 24) | ((size_t) (*p)[2] << 16) |
-                       ((size_t) (*p)[3] << 8) |           (*p)[4];
-                (*p) += 5;
-                break;
-
-            default:
-                return MBEDTLS_ERR_ASN1_INVALID_LENGTH;
+        int n = (**p) & 0x7F;
+        if (n == 0 || n > 4) {
+            return MBEDTLS_ERR_ASN1_INVALID_LENGTH;
+        }
+        if ((end - *p) <= n) {
+            return MBEDTLS_ERR_ASN1_OUT_OF_DATA;
+        }
+        *len = 0;
+        (*p)++;
+        while (n--) {
+            *len = (*len << 8) | **p;
+            (*p)++;
         }
     }
 
@@ -114,7 +74,9 @@
 
     return mbedtls_asn1_get_len(p, end, len);
 }
+#endif /* MBEDTLS_ASN1_PARSE_C || MBEDTLS_X509_CREATE_C || MBEDTLS_PSA_UTIL_HAVE_ECDSA */
 
+#if defined(MBEDTLS_ASN1_PARSE_C)
 int mbedtls_asn1_get_bool(unsigned char **p,
                           const unsigned char *end,
                           int *val)