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/programs/test/udp_proxy.c b/programs/test/udp_proxy.c
index 1c8b500..307e706 100644
--- a/programs/test/udp_proxy.c
+++ b/programs/test/udp_proxy.c
@@ -42,6 +42,7 @@
 #define mbedtls_printf          printf
 #define mbedtls_calloc          calloc
 #define mbedtls_free            free
+#define mbedtls_exit            exit
 #define MBEDTLS_EXIT_SUCCESS    EXIT_SUCCESS
 #define MBEDTLS_EXIT_FAILURE    EXIT_FAILURE
 #endif /* MBEDTLS_PLATFORM_C */
@@ -50,7 +51,7 @@
 int main( void )
 {
     mbedtls_printf( "MBEDTLS_NET_C not defined.\n" );
-    return( 0 );
+    mbedtls_exit( 0 );
 }
 #else
 
@@ -146,6 +147,7 @@
     "                        modifying CID in first instance of the packet.\n" \
     "    protect_hvr=0/1     default: 0 (don't protect HelloVerifyRequest)\n" \
     "    protect_len=%%d      default: (don't protect packets of this size)\n" \
+    "    inject_clihlo=0/1   default: 0 (don't inject fake ClientHello)\n"  \
     "\n"                                                                    \
     "    seed=%%d             default: (use current time)\n"                \
     USAGE_PACK                                                              \
@@ -179,6 +181,7 @@
     unsigned bad_cid;           /* inject corrupted CID record              */
     int protect_hvr;            /* never drop or delay HelloVerifyRequest   */
     int protect_len;            /* never drop/delay packet of the given size*/
+    int inject_clihlo;          /* inject fake ClientHello after handshake  */
     unsigned pack;              /* merge packets into single datagram for
                                  * at most \c merge milliseconds if > 0     */
     unsigned int seed;          /* seed for "random" events                 */
@@ -327,6 +330,12 @@
             if( opt.protect_len < 0 )
                 exit_usage( p, q );
         }
+        else if( strcmp( p, "inject_clihlo" ) == 0 )
+        {
+            opt.inject_clihlo = atoi( q );
+            if( opt.inject_clihlo < 0 || opt.inject_clihlo > 1 )
+                exit_usage( p, q );
+        }
         else if( strcmp( p, "seed" ) == 0 )
         {
             opt.seed = atoi( q );
@@ -536,11 +545,41 @@
     fflush( stdout );
 }
 
+/*
+ * In order to test the server's behaviour when receiving a ClientHello after
+ * the connection is established (this could be a hard reset from the client,
+ * but the server must not drop the existing connection before establishing
+ * client reachability, see RFC 6347 Section 4.2.8), we memorize the first
+ * ClientHello we see (which can't have a cookie), then replay it after the
+ * first ApplicationData record - then we're done.
+ *
+ * This is controlled by the inject_clihlo option.
+ *
+ * We want an explicit state and a place to store the packet.
+ */
+typedef enum {
+    ICH_INIT,       /* haven't seen the first ClientHello yet */
+    ICH_CACHED,     /* cached the initial ClientHello */
+    ICH_INJECTED,   /* ClientHello already injected, done */
+} inject_clihlo_state_t;
+
+static inject_clihlo_state_t inject_clihlo_state;
+static packet initial_clihlo;
+
 int send_packet( const packet *p, const char *why )
 {
     int ret;
     mbedtls_net_context *dst = p->dst;
 
+    /* save initial ClientHello? */
+    if( opt.inject_clihlo != 0 &&
+        inject_clihlo_state == ICH_INIT &&
+        strcmp( p->type, "ClientHello" ) == 0 )
+    {
+        memcpy( &initial_clihlo, p, sizeof( packet ) );
+        inject_clihlo_state = ICH_CACHED;
+    }
+
     /* insert corrupted CID record? */
     if( opt.bad_cid != 0 &&
         strcmp( p->type, "CID" ) == 0 &&
@@ -605,6 +644,23 @@
         }
     }
 
+    /* Inject ClientHello after first ApplicationData */
+    if( opt.inject_clihlo != 0 &&
+        inject_clihlo_state == ICH_CACHED &&
+        strcmp( p->type, "ApplicationData" ) == 0 )
+    {
+        print_packet( &initial_clihlo, "injected" );
+
+        if( ( ret = dispatch_data( dst, initial_clihlo.buf,
+                                        initial_clihlo.len ) ) <= 0 )
+        {
+            mbedtls_printf( "  ! dispatch returned %d\n", ret );
+            return( ret );
+        }
+
+        inject_clihlo_state = ICH_INJECTED;
+    }
+
     return( 0 );
 }
 
@@ -977,7 +1033,7 @@
     fflush( stdout ); getchar();
 #endif
 
-    return( exit_code );
+    mbedtls_exit( exit_code );
 }
 
 #endif /* MBEDTLS_NET_C */