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/net_sockets.c b/lib/libmbedtls/mbedtls/library/net_sockets.c
index bb313c2..5fbe1f7 100644
--- a/lib/libmbedtls/mbedtls/library/net_sockets.c
+++ b/lib/libmbedtls/mbedtls/library/net_sockets.c
@@ -1,8 +1,8 @@
-// SPDX-License-Identifier: Apache-2.0
 /*
  *  TCP/IP or UDP/IP networking functions
  *
- *  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.
@@ -15,26 +15,25 @@
  *  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)
  */
 
 /* Enable definition of getaddrinfo() even when compiling with -std=c99. Must
  * be set before config.h, which pulls in glibc's features.h indirectly.
  * Harmless on other platforms. */
+#ifndef _POSIX_C_SOURCE
 #define _POSIX_C_SOURCE 200112L
-
-#if !defined(MBEDTLS_CONFIG_FILE)
-#include "mbedtls/config.h"
-#else
-#include MBEDTLS_CONFIG_FILE
 #endif
+#ifndef _XOPEN_SOURCE
+#define _XOPEN_SOURCE 600 /* sockaddr_storage */
+#endif
+
+#include "common.h"
 
 #if defined(MBEDTLS_NET_C)
 
 #if !defined(unix) && !defined(__unix__) && !defined(__unix) && \
     !defined(__APPLE__) && !defined(_WIN32) && !defined(__QNXNTO__) && \
-    !defined(__HAIKU__)
+    !defined(__HAIKU__) && !defined(__midipix__)
 #error "This module only works on Unix and Windows, see MBEDTLS_NET_C in config.h"
 #endif
 
@@ -54,8 +53,7 @@
 
 #define IS_EINTR( ret ) ( ( ret ) == WSAEINTR )
 
-#if !defined(_WIN32_WINNT) || (_WIN32_WINNT < 0x0501)
-#undef _WIN32_WINNT
+#if !defined(_WIN32_WINNT)
 /* Enables getaddrinfo() & Co */
 #define _WIN32_WINNT 0x0501
 #endif
@@ -64,6 +62,9 @@
 
 #include <winsock2.h>
 #include <windows.h>
+#if (_WIN32_WINNT < 0x0501)
+#include <wspiapi.h>
+#endif
 
 #if defined(_MSC_VER)
 #if defined(_WIN32_WCE)
@@ -135,6 +136,31 @@
 }
 
 /*
+ * Return 0 if the file descriptor is valid, an error otherwise.
+ * If for_select != 0, check whether the file descriptor is within the range
+ * allowed for fd_set used for the FD_xxx macros and the select() function.
+ */
+static int check_fd( int fd, int for_select )
+{
+    if( fd < 0 )
+        return( MBEDTLS_ERR_NET_INVALID_CONTEXT );
+
+#if (defined(_WIN32) || defined(_WIN32_WCE)) && !defined(EFIX64) && \
+    !defined(EFI32)
+    (void) for_select;
+#else
+    /* A limitation of select() is that it only works with file descriptors
+     * that are strictly less than FD_SETSIZE. This is a limitation of the
+     * fd_set type. Error out early, because attempting to call FD_SET on a
+     * large file descriptor is a buffer overflow on typical platforms. */
+    if( for_select && fd >= FD_SETSIZE )
+        return( MBEDTLS_ERR_NET_POLL_FAILED );
+#endif
+
+    return( 0 );
+}
+
+/*
  * Initialize a context
  */
 void mbedtls_net_init( mbedtls_net_context *ctx )
@@ -320,7 +346,8 @@
     struct sockaddr_storage client_addr;
 
 #if defined(__socklen_t_defined) || defined(_SOCKLEN_T) ||  \
-    defined(_SOCKLEN_T_DECLARED) || defined(__DEFINED_socklen_t)
+    defined(_SOCKLEN_T_DECLARED) || defined(__DEFINED_socklen_t) || \
+    defined(socklen_t) || (defined(_POSIX_VERSION) && _POSIX_VERSION >= 200112L)
     socklen_t n = (socklen_t) sizeof( client_addr );
     socklen_t type_len = (socklen_t) sizeof( type );
 #else
@@ -464,8 +491,9 @@
 
     int fd = ctx->fd;
 
-    if( fd < 0 )
-        return( MBEDTLS_ERR_NET_INVALID_CONTEXT );
+    ret = check_fd( fd, 1 );
+    if( ret != 0 )
+        return( ret );
 
 #if defined(__has_feature)
 #if __has_feature(memory_sanitizer)
@@ -544,8 +572,9 @@
     int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
     int fd = ((mbedtls_net_context *) ctx)->fd;
 
-    if( fd < 0 )
-        return( MBEDTLS_ERR_NET_INVALID_CONTEXT );
+    ret = check_fd( fd, 0 );
+    if( ret != 0 )
+        return( ret );
 
     ret = (int) read( fd, buf, len );
 
@@ -583,8 +612,9 @@
     fd_set read_fds;
     int fd = ((mbedtls_net_context *) ctx)->fd;
 
-    if( fd < 0 )
-        return( MBEDTLS_ERR_NET_INVALID_CONTEXT );
+    ret = check_fd( fd, 1 );
+    if( ret != 0 )
+        return( ret );
 
     FD_ZERO( &read_fds );
     FD_SET( fd, &read_fds );
@@ -624,8 +654,9 @@
     int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
     int fd = ((mbedtls_net_context *) ctx)->fd;
 
-    if( fd < 0 )
-        return( MBEDTLS_ERR_NET_INVALID_CONTEXT );
+    ret = check_fd( fd, 0 );
+    if( ret != 0 )
+        return( ret );
 
     ret = (int) write( fd, buf, len );