Merge mbedtls 2.16.6 into baremetal

Conflicts:
mbedtls.doxyfile - PROJECT_NAME - mbed TLS v2.16.6 chosen.
doc_mainpage.h - mbed TLS v2.16.6 version chosen.
hmac_drbg.h - line 260, extended description chosen.
            - line 313, extended description chosen.
            - line 338, extended description chosen.
version.h - 2.16.6 chosen.
CMakeLists.txt - 2.16.6 chosen.
test_suite_version.data - 2.16.6 chosen.
Makefile - 141 - manual correction - baremetal version of C_SOURCE_FILES
                 with variables for directories plus 2.16.6 CTAGS addition.
pkparse.c - lines 846 onwards - the asn1_get_nonzero_mpi implementation chosen.
ssl_tls.c - line 5269 - edited manually, left the ret=0, because baremetal has
            a different behaviour since commit 87b5626, but added a debug
            message that's new in 2.16.6.    
all.sh:
- component_build_deprecated - chosen the refactored version from 2.16.6,
                               but with extra flags from baremetal.
- rest of the _no_xxx tests - merged make options to have PTHREAD=1 and
                              other changes from 2.16.6 (like -O1 instead of -O0).
- component_build_arm_none_eabi_gcc_no_64bit_multiplication - added 
                              TINYCRYPT_BUILD=0 to the 2.16.6 version of make.

x509/req_app.c - left baremetal log but with mbedtls_exit( 0 ) call.
x509/crl_app.c - left baremetal log but with mbedtls_exit( 0 ) call.
x509/cert_app.c - left baremetal log but with mbedtls_exit( 0 ) call.
ssl/ssl_mail_client.c - left baremetal log but with mbedtls_exit( 0 ) call.
ssl/ssl_pthread_server.c - left baremetal log but with mbedtls_exit( 0 ) call.
ssl/ssl_fork_server.c - left baremetal log but with mbedtls_exit( 0 ) call.
ssl_client1.c - line 54 - left baremetal log but with mbedtls_exit( 0 ) call.
ssl_client2.c - line 54 - left baremetal log but with mbedtls_exit( 0 ) call.
              - line 132 - new options of both branches added.
              - skip close notify handled as in 2.16.6, but with `ssl` instead of `&ssl`.
              - Merged the 2.16.6 usage split with additional baremetal usages.
              - Merged options from baremetal and 2.16.6.
ssl_server.c - left baremetal log but with mbedtls_exit( 0 ) call.
ssl_server2.c - Merged the 2.16.6 usage split with additional baremetal usages.
config.pl - fixed missing defines from the documentation, removed duplicates,
            and reorganised so that the documentation and excluded list
            are ordered in the same way.
test_suite_x509parse.data - only added the two new pathlen tests.
x509_crt.c - change the return code by removing
             MBEDTLS_ERR_X509_INVALID_EXTENSIONS, since it's added by
             x509_crt_frame_parse_ext not by an "or", but by "+=".
Changelog - Assigned all entries to appropriate sections.
ssl-opt.sh - line 8263 - merged options.
           - removed lines 1165 - 1176 - there was a duplicate test, probably
             an artifact of previous merges.
check-files.py - sticked to old formatting.

Signed-off-by: Andrzej Kurek <andrzej.kurek@arm.com>
diff --git a/library/ssl_tls.c b/library/ssl_tls.c
index 146a8f1..fea3b8a 100644
--- a/library/ssl_tls.c
+++ b/library/ssl_tls.c
@@ -1529,8 +1529,6 @@
 #if defined(MBEDTLS_SSL_HW_RECORD_ACCEL)
     if( mbedtls_ssl_hw_record_init != NULL )
     {
-        int ret = 0;
-
         MBEDTLS_SSL_DEBUG_MSG( 2, ( "going for mbedtls_ssl_hw_record_init()" ) );
 
         if( ( ret = mbedtls_ssl_hw_record_init( ssl, key1, key2, keylen,
@@ -4084,15 +4082,18 @@
 /*
  * Swap transform_out and out_ctr with the alternative ones
  */
-static void ssl_swap_epochs( mbedtls_ssl_context *ssl )
+static int ssl_swap_epochs( mbedtls_ssl_context *ssl )
 {
     mbedtls_ssl_transform *tmp_transform;
     unsigned char tmp_out_ctr[8];
+#if defined(MBEDTLS_SSL_HW_RECORD_ACCEL)
+    int ret;
+#endif /* MBEDTLS_SSL_HW_RECORD_ACCEL */
 
     if( ssl->transform_out == ssl->handshake->alt_transform_out )
     {
         MBEDTLS_SSL_DEBUG_MSG( 3, ( "skip swap epochs" ) );
-        return;
+        return( 0 );
     }
 
     MBEDTLS_SSL_DEBUG_MSG( 3, ( "swap epochs" ) );
@@ -4119,7 +4120,9 @@
             return( MBEDTLS_ERR_SSL_HW_ACCEL_FAILED );
         }
     }
-#endif
+#endif /* MBEDTLS_SSL_HW_RECORD_ACCEL */
+
+    return( 0 );
 }
 
 /*
@@ -4156,7 +4159,8 @@
 
         ssl->handshake->cur_msg = ssl->handshake->flight;
         ssl->handshake->cur_msg_p = ssl->handshake->flight->p + 12;
-        ssl_swap_epochs( ssl );
+        if( ( ret = ssl_swap_epochs( ssl ) ) != 0 )
+            return( ret );
 
         ssl->handshake->retransmit_state = MBEDTLS_SSL_RETRANS_SENDING;
     }
@@ -4179,7 +4183,8 @@
         if( is_finished && ssl->handshake->cur_msg_p == ( cur->p + 12 ) )
         {
             MBEDTLS_SSL_DEBUG_MSG( 2, ( "swap epochs to send finished message" ) );
-            ssl_swap_epochs( ssl );
+            if( ( ret = ssl_swap_epochs( ssl ) ) != 0 )
+                return( ret );
         }
 
         ret = ssl_get_remaining_payload_in_datagram( ssl );
@@ -4216,7 +4221,10 @@
             if( ( max_frag_len < 12 ) || ( max_frag_len == 12 && hs_len != 0 ) )
             {
                 if( is_finished )
-                    ssl_swap_epochs( ssl );
+                {
+                    if( ( ret = ssl_swap_epochs( ssl ) ) != 0 )
+                        return( ret );
+                }
 
                 if( ( ret = mbedtls_ssl_flush_output( ssl ) ) != 0 )
                     return( ret );
@@ -5263,16 +5271,22 @@
 
     if( ret == MBEDTLS_ERR_SSL_HELLO_VERIFY_REQUIRED )
     {
+        int send_ret;
+        MBEDTLS_SSL_DEBUG_MSG( 1, ( "sending HelloVerifyRequest" ) );
+        MBEDTLS_SSL_DEBUG_BUF( 4, "output record sent to network",
+                                  ssl->out_buf, len );
         /* Don't check write errors as we can't do anything here.
          * If the error is permanent we'll catch it later,
          * if it's not, then hopefully it'll work next time. */
-        (void) mbedtls_ssl_get_send( ssl )( ssl->p_bio, ssl->out_buf, len );
+        send_ret = mbedtls_ssl_get_send( ssl )( ssl->p_bio, ssl->out_buf, len );
+        MBEDTLS_SSL_DEBUG_RET( 2, "mbedtls_ssl_get_send", send_ret );
+        (void) send_ret;
         ret = 0;
     }
 
     if( ret == 0 )
     {
-        /* Got a valid cookie, partially reset context */
+        MBEDTLS_SSL_DEBUG_MSG( 1, ( "cookie is valid, resetting context" ) );
         if( ( ret = ssl_session_reset_int( ssl, 1 ) ) != 0 )
         {
             MBEDTLS_SSL_DEBUG_RET( 1, "reset", ret );