Import mbedtls-2.27.0

Imports Mbed TLS 2.27.0 from https://github.com/ARMmbed/mbedtls.git
commit f71e28780841 ("Merge pull request #843 from
paul-elliott-arm/mbedtls-2.27.0rc0-pr") (tag mbedtls-2.27.0, v2.27.0).

Files that are not needed are removed.

 cd lib/libmbedtls
 rm -rf mbedtls
 cp -R path/to/mbedtls-2.27.0/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 -rf .git .github doxygen configs programs scripts tests visualc yotta
 rm -rf 3rdparty ChangeLog.d docs
 rm -rf include/mbedtls/config_psa.h include/psa
 rm library/psa_* library/mps_*
 cd ..
 git add mbedtls

This is a complete overwrite of previous code so earlier changes in the
previous branch import/mbedtls-2.22.0 will be added on top of this commit.

Signed-off-by: Jerome Forissier <jerome@forissier.org>
diff --git a/lib/libmbedtls/mbedtls/library/ssl_cookie.c b/lib/libmbedtls/mbedtls/library/ssl_cookie.c
index 0b566d6..69d1b32 100644
--- a/lib/libmbedtls/mbedtls/library/ssl_cookie.c
+++ b/lib/libmbedtls/mbedtls/library/ssl_cookie.c
@@ -1,8 +1,8 @@
-// SPDX-License-Identifier: Apache-2.0
 /*
  *  DTLS cookie callbacks implementation
  *
- *  Copyright (C) 2006-2015, ARM Limited, All Rights Reserved
+ *  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.
@@ -15,19 +15,13 @@
  *  WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  *  See the License for the specific language governing permissions and
  *  limitations under the License.
- *
- *  This file is part of mbed TLS (https://tls.mbed.org)
  */
 /*
  * These session callbacks use a simple chained list
  * to store and retrieve the session information.
  */
 
-#if !defined(MBEDTLS_CONFIG_FILE)
-#include "mbedtls/config.h"
-#else
-#include MBEDTLS_CONFIG_FILE
-#endif
+#include "common.h"
 
 #if defined(MBEDTLS_SSL_COOKIE_C)
 
@@ -134,8 +128,7 @@
 {
     unsigned char hmac_out[COOKIE_MD_OUTLEN];
 
-    if( (size_t)( end - *p ) < COOKIE_HMAC_LEN )
-        return( MBEDTLS_ERR_SSL_BUFFER_TOO_SMALL );
+    MBEDTLS_SSL_CHK_BUF_PTR( *p, end, COOKIE_HMAC_LEN );
 
     if( mbedtls_md_hmac_reset(  hmac_ctx ) != 0 ||
         mbedtls_md_hmac_update( hmac_ctx, time, 4 ) != 0 ||
@@ -165,8 +158,7 @@
     if( ctx == NULL || cli_id == NULL )
         return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA );
 
-    if( (size_t)( end - *p ) < COOKIE_LEN )
-        return( MBEDTLS_ERR_SSL_BUFFER_TOO_SMALL );
+    MBEDTLS_SSL_CHK_BUF_PTR( *p, end, COOKIE_LEN );
 
 #if defined(MBEDTLS_HAVE_TIME)
     t = (unsigned long) mbedtls_time( NULL );
@@ -182,7 +174,7 @@
 
 #if defined(MBEDTLS_THREADING_C)
     if( ( ret = mbedtls_mutex_lock( &ctx->mutex ) ) != 0 )
-        return( MBEDTLS_ERR_SSL_INTERNAL_ERROR + ret );
+        return( MBEDTLS_ERROR_ADD( MBEDTLS_ERR_SSL_INTERNAL_ERROR, ret ) );
 #endif
 
     ret = ssl_cookie_hmac( &ctx->hmac_ctx, *p - 4,
@@ -190,8 +182,8 @@
 
 #if defined(MBEDTLS_THREADING_C)
     if( mbedtls_mutex_unlock( &ctx->mutex ) != 0 )
-        return( MBEDTLS_ERR_SSL_INTERNAL_ERROR +
-                MBEDTLS_ERR_THREADING_MUTEX_ERROR );
+        return( MBEDTLS_ERROR_ADD( MBEDTLS_ERR_SSL_INTERNAL_ERROR,
+                MBEDTLS_ERR_THREADING_MUTEX_ERROR ) );
 #endif
 
     return( ret );
@@ -218,7 +210,7 @@
 
 #if defined(MBEDTLS_THREADING_C)
     if( ( ret = mbedtls_mutex_lock( &ctx->mutex ) ) != 0 )
-        return( MBEDTLS_ERR_SSL_INTERNAL_ERROR + ret );
+        return( MBEDTLS_ERROR_ADD( MBEDTLS_ERR_SSL_INTERNAL_ERROR, ret ) );
 #endif
 
     if( ssl_cookie_hmac( &ctx->hmac_ctx, cookie,
@@ -228,8 +220,8 @@
 
 #if defined(MBEDTLS_THREADING_C)
     if( mbedtls_mutex_unlock( &ctx->mutex ) != 0 )
-        return( MBEDTLS_ERR_SSL_INTERNAL_ERROR +
-                MBEDTLS_ERR_THREADING_MUTEX_ERROR );
+        return( MBEDTLS_ERROR_ADD( MBEDTLS_ERR_SSL_INTERNAL_ERROR,
+                MBEDTLS_ERR_THREADING_MUTEX_ERROR ) );
 #endif
 
     if( ret != 0 )