Merge branch 'baremetal' into baremetal-2.16-20190909

* baremetal: (78 commits)
  Review corrections 6
  Review corrections 5
  Minor changes to tinycrypt README
  Typos in the tinycrypt README
  Addition of copyright statements to tinycrypt files
  Add LICENSE and README for tinycrypt
  Add SPDX lines to each imported TinyCrypt file
  Review corrections 4
  Review corrections 3
  Review corrections 2
  Review corrections
  Update signature of BE conversion functions
  Use function for 16/24/32-bit BE conversion
  x509.c: Minor readability improvement
  x509_crt.c: Indicate guarding condition in #else branch
  X.509: Don't remove verify callback by default
  Fix Doxygen warnings regarding removed verify cb+ctx parameters
  ECC restart: Use optional verification mode in bad signature test
  Re-implement verify chain if vrfy cbs are disabled
  Add zero-cost abstraction layer for CRT verification chain
  ...

library/platform_util.c

@@ -137,3 +137,54 @@ struct tm *mbedtls_platform_gmtime_r( const mbedtls_time_t *tt,
 #endif /* _WIN32 && !EFIX64 && !EFI32 */
 }
 #endif /* MBEDTLS_HAVE_TIME_DATE && MBEDTLS_PLATFORM_GMTIME_R_ALT */
+
+unsigned char* mbedtls_platform_put_uint32_be( unsigned char *buf,
+                                               size_t num )
+{
+    *buf++ = (unsigned char) ( num >> 24 );
+    *buf++ = (unsigned char) ( num >> 16 );
+    *buf++ = (unsigned char) ( num >> 8  );
+    *buf++ = (unsigned char) ( num       );
+
+    return buf;
+}
+
+unsigned char* mbedtls_platform_put_uint24_be( unsigned char *buf,
+                                               size_t num )
+{
+    *buf++ = (unsigned char) ( num >> 16 );
+    *buf++ = (unsigned char) ( num >> 8  );
+    *buf++ = (unsigned char) ( num       );
+
+    return buf;
+}
+
+unsigned char* mbedtls_platform_put_uint16_be( unsigned char *buf,
+                                               size_t num )
+{
+    *buf++ = (unsigned char) ( num >> 8 );
+    *buf++ = (unsigned char) ( num      );
+
+    return buf;
+}
+
+size_t mbedtls_platform_get_uint32_be( const unsigned char *buf )
+{
+    return ( ( (unsigned int) buf[0] << 24 ) |
+             ( (unsigned int) buf[1] << 16 ) |
+             ( (unsigned int) buf[2] <<  8 ) |
+             ( (unsigned int) buf[3]       ) );
+}
+
+size_t mbedtls_platform_get_uint24_be( const unsigned char *buf )
+{
+    return ( ( buf[0] << 16 ) |
+             ( buf[1] <<  8)  |
+             ( buf[2]      ) );
+}
+
+size_t mbedtls_platform_get_uint16_be( const unsigned char *buf )
+{
+    return ( ( buf[0] << 8 )  |
+             ( buf[1]      ) );
+}