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_ticket.c b/lib/libmbedtls/mbedtls/library/ssl_ticket.c
index ddc88db..626d137 100644
--- a/lib/libmbedtls/mbedtls/library/ssl_ticket.c
+++ b/lib/libmbedtls/mbedtls/library/ssl_ticket.c
@@ -1,8 +1,8 @@
-// SPDX-License-Identifier: Apache-2.0
 /*
  *  TLS server tickets 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.
@@ -15,15 +15,9 @@
  *  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)
  */
 
-#if !defined(MBEDTLS_CONFIG_FILE)
-#include "mbedtls/config.h"
-#else
-#include MBEDTLS_CONFIG_FILE
-#endif
+#include "common.h"
 
 #if defined(MBEDTLS_SSL_TICKET_C)
 
@@ -35,6 +29,7 @@
 #define mbedtls_free      free
 #endif
 
+#include "mbedtls/ssl_internal.h"
 #include "mbedtls/ssl_ticket.h"
 #include "mbedtls/error.h"
 #include "mbedtls/platform_util.h"
@@ -214,7 +209,6 @@
     unsigned char *iv = start + TICKET_KEY_NAME_BYTES;
     unsigned char *state_len_bytes = iv + TICKET_IV_BYTES;
     unsigned char *state = state_len_bytes + TICKET_CRYPT_LEN_BYTES;
-    unsigned char *tag;
     size_t clear_len, ciph_len;
 
     *tlen = 0;
@@ -224,8 +218,7 @@
 
     /* We need at least 4 bytes for key_name, 12 for IV, 2 for len 16 for tag,
      * in addition to session itself, that will be checked when writing it. */
-    if( end - start < TICKET_MIN_LEN )
-        return( MBEDTLS_ERR_SSL_BUFFER_TOO_SMALL );
+    MBEDTLS_SSL_CHK_BUF_PTR( start, end, TICKET_MIN_LEN );
 
 #if defined(MBEDTLS_THREADING_C)
     if( ( ret = mbedtls_mutex_lock( &ctx->mutex ) ) != 0 )
@@ -256,23 +249,23 @@
     state_len_bytes[1] = ( clear_len      ) & 0xff;
 
     /* Encrypt and authenticate */
-    tag = state + clear_len;
-    if( ( ret = mbedtls_cipher_auth_encrypt( &key->ctx,
+    if( ( ret = mbedtls_cipher_auth_encrypt_ext( &key->ctx,
                     iv, TICKET_IV_BYTES,
                     /* Additional data: key name, IV and length */
                     key_name, TICKET_ADD_DATA_LEN,
-                    state, clear_len, state, &ciph_len,
-                    tag, TICKET_AUTH_TAG_BYTES ) ) != 0 )
+                    state, clear_len,
+                    state, end - state, &ciph_len,
+                    TICKET_AUTH_TAG_BYTES ) ) != 0 )
     {
         goto cleanup;
     }
-    if( ciph_len != clear_len )
+    if( ciph_len != clear_len + TICKET_AUTH_TAG_BYTES )
     {
         ret = MBEDTLS_ERR_SSL_INTERNAL_ERROR;
         goto cleanup;
     }
 
-    *tlen = TICKET_MIN_LEN + ciph_len;
+    *tlen = TICKET_MIN_LEN + ciph_len - TICKET_AUTH_TAG_BYTES;
 
 cleanup:
 #if defined(MBEDTLS_THREADING_C)
@@ -314,7 +307,6 @@
     unsigned char *iv = buf + TICKET_KEY_NAME_BYTES;
     unsigned char *enc_len_p = iv + TICKET_IV_BYTES;
     unsigned char *ticket = enc_len_p + TICKET_CRYPT_LEN_BYTES;
-    unsigned char *tag;
     size_t enc_len, clear_len;
 
     if( ctx == NULL || ctx->f_rng == NULL )
@@ -332,7 +324,6 @@
         goto cleanup;
 
     enc_len = ( enc_len_p[0] << 8 ) | enc_len_p[1];
-    tag = ticket + enc_len;
 
     if( len != TICKET_MIN_LEN + enc_len )
     {
@@ -350,13 +341,13 @@
     }
 
     /* Decrypt and authenticate */
-    if( ( ret = mbedtls_cipher_auth_decrypt( &key->ctx,
+    if( ( ret = mbedtls_cipher_auth_decrypt_ext( &key->ctx,
                     iv, TICKET_IV_BYTES,
                     /* Additional data: key name, IV and length */
                     key_name, TICKET_ADD_DATA_LEN,
-                    ticket, enc_len,
-                    ticket, &clear_len,
-                    tag, TICKET_AUTH_TAG_BYTES ) ) != 0 )
+                    ticket, enc_len + TICKET_AUTH_TAG_BYTES,
+                    ticket, enc_len, &clear_len,
+                    TICKET_AUTH_TAG_BYTES ) ) != 0 )
     {
         if( ret == MBEDTLS_ERR_CIPHER_AUTH_FAILED )
             ret = MBEDTLS_ERR_SSL_INVALID_MAC;