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/debug.c b/lib/libmbedtls/mbedtls/library/debug.c
index 46b6f6e..e108600 100644
--- a/lib/libmbedtls/mbedtls/library/debug.c
+++ b/lib/libmbedtls/mbedtls/library/debug.c
@@ -1,8 +1,8 @@
-// SPDX-License-Identifier: Apache-2.0
 /*
  *  Debugging routines
  *
- *  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_DEBUG_C)
 
@@ -80,6 +74,7 @@
 #endif
 }
 
+MBEDTLS_PRINTF_ATTRIBUTE(5, 6)
 void mbedtls_debug_print_msg( const mbedtls_ssl_context *ssl, int level,
                               const char *file, int line,
                               const char *format, ... )
@@ -132,7 +127,7 @@
         return;
 
     mbedtls_snprintf( str, sizeof( str ), "%s() returned %d (-0x%04x)\n",
-              text, ret, -ret );
+              text, ret, (unsigned int) -ret );
 
     debug_send_line( ssl, level, file, line, str );
 }
@@ -225,8 +220,8 @@
                       const char *text, const mbedtls_mpi *X )
 {
     char str[DEBUG_BUF_SIZE];
-    int j, k, zeros = 1;
-    size_t i, n, idx = 0;
+    size_t bitlen;
+    size_t idx = 0;
 
     if( NULL == ssl              ||
         NULL == ssl->conf        ||
@@ -237,55 +232,43 @@
         return;
     }
 
-    for( n = X->n - 1; n > 0; n-- )
-        if( X->p[n] != 0 )
-            break;
+    bitlen = mbedtls_mpi_bitlen( X );
 
-    for( j = ( sizeof(mbedtls_mpi_uint) << 3 ) - 1; j >= 0; j-- )
-        if( ( ( X->p[n] >> j ) & 1 ) != 0 )
-            break;
-
-    mbedtls_snprintf( str + idx, sizeof( str ) - idx, "value of '%s' (%d bits) is:\n",
-              text, (int) ( ( n * ( sizeof(mbedtls_mpi_uint) << 3 ) ) + j + 1 ) );
-
+    mbedtls_snprintf( str, sizeof( str ), "value of '%s' (%u bits) is:\n",
+                      text, (unsigned) bitlen );
     debug_send_line( ssl, level, file, line, str );
 
-    idx = 0;
-    for( i = n + 1, j = 0; i > 0; i-- )
+    if( bitlen == 0 )
     {
-        if( zeros && X->p[i - 1] == 0 )
-            continue;
-
-        for( k = sizeof( mbedtls_mpi_uint ) - 1; k >= 0; k-- )
+        str[0] = ' '; str[1] = '0'; str[2] = '0';
+        idx = 3;
+    }
+    else
+    {
+        int n;
+        for( n = (int) ( ( bitlen - 1 ) / 8 ); n >= 0; n-- )
         {
-            if( zeros && ( ( X->p[i - 1] >> ( k << 3 ) ) & 0xFF ) == 0 )
-                continue;
-            else
-                zeros = 0;
-
-            if( j % 16 == 0 )
+            size_t limb_offset = n / sizeof( mbedtls_mpi_uint );
+            size_t offset_in_limb = n % sizeof( mbedtls_mpi_uint );
+            unsigned char octet =
+                ( X->p[limb_offset] >> ( offset_in_limb * 8 ) ) & 0xff;
+            mbedtls_snprintf( str + idx, sizeof( str ) - idx, " %02x", octet );
+            idx += 3;
+            /* Wrap lines after 16 octets that each take 3 columns */
+            if( idx >= 3 * 16 )
             {
-                if( j > 0 )
-                {
-                    mbedtls_snprintf( str + idx, sizeof( str ) - idx, "\n" );
-                    debug_send_line( ssl, level, file, line, str );
-                    idx = 0;
-                }
+                mbedtls_snprintf( str + idx, sizeof( str ) - idx, "\n" );
+                debug_send_line( ssl, level, file, line, str );
+                idx = 0;
             }
-
-            idx += mbedtls_snprintf( str + idx, sizeof( str ) - idx, " %02x", (unsigned int)
-                             ( X->p[i - 1] >> ( k << 3 ) ) & 0xFF );
-
-            j++;
         }
-
     }
 
-    if( zeros == 1 )
-        idx += mbedtls_snprintf( str + idx, sizeof( str ) - idx, " 00" );
-
-    mbedtls_snprintf( str + idx, sizeof( str ) - idx, "\n" );
-    debug_send_line( ssl, level, file, line, str );
+    if( idx != 0 )
+    {
+        mbedtls_snprintf( str + idx, sizeof( str ) - idx, "\n" );
+        debug_send_line( ssl, level, file, line, str );
+    }
 }
 #endif /* MBEDTLS_BIGNUM_C */