Kconfig.mbedtls

# Kconfig - Cryptography primitive options for mbed TLS

# Copyright (c) 2016 Intel Corporation
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

menuconfig MBEDTLS
	bool "mbedTLS Support"
	help
	  This option enables the mbedTLS cryptography library.

if MBEDTLS

choice
	prompt "Select implementation"
	default MBEDTLS_BUILTIN

config MBEDTLS_BUILTIN
	bool "Enable mbedTLS integrated sources"
	help
	  Link with local mbedTLS sources instead of external library.

config MBEDTLS_LIBRARY
	bool "Enable mbedTLS external library"
	help
	  This option enables mbedTLS library.

endchoice

config MBEDTLS_CFG_FILE
	string "mbed TLS configuration file"
	depends on MBEDTLS_BUILTIN
	default "config-tls-generic.h"
	help
	  Use a specific mbed TLS configuration file. The default config file
	  file can be tweaked with Kconfig. The default configuration is
	  suitable to communicate with majority of HTTPS servers on the Internet,
	  but has relatively many features enabled. To optimize resources for
	  special TLS usage, use available Kconfig options, or select an
	  alternative config.

if MBEDTLS_BUILTIN && MBEDTLS_CFG_FILE = "config-tls-generic.h"
rsource "Kconfig.tls-generic"
endif

config MBEDTLS_SSL_MAX_CONTENT_LEN
	int "Max payload size for TLS protocol message"
	default 1500
	depends on MBEDTLS_BUILTIN
	help
	  The TLS standards mandate max payload size of 16384 bytes. So, for
	  maximum operability and for general-purpose usage, that value must
	  be used. For specific usages, that value can be largely decreased.
	  E.g. for DTLS, payload size is limited by UDP datagram size, and
	  even for HTTPS REST API, the payload can be limited to max size of
	  (REST request, REST response, server certificate(s)).
	  mbedTLS uses this value separate for input and output buffers, so
	  twice this value will be allocated (on mbedTLS own heap, so the
	  value of MBEDTLS_HEAP_SIZE should accommodate that).

config MBEDTLS_DEBUG
	bool "mbed TLS debug activation"
	depends on MBEDTLS_BUILTIN
	help
	  Enable debugging activation for mbed TLS configuration. If you use
	  mbedTLS/Zephyr integration (e.g. net_app), this will activate debug
	  logging (of the level configured by MBEDTLS_DEBUG_LEVEL).
	  If you use mbedTLS directly instead, you will need to perform
	  additional configuration yourself: call
	  mbedtls_ssl_conf_dbg(&mbedtls.conf, my_debug, NULL);
	  mbedtls_debug_set_threshold(level);
	  functions in your application, and create the my_debug() function to
	  actually print something useful.

config MBEDTLS_DEBUG_LEVEL
	int "mbed TLS default debug level"
	depends on MBEDTLS_DEBUG
	default 0
	range 0 4
	help
	  Default mbed TLS debug logging level for Zephyr integration code
	  (from ext/lib/crypto/mbedtls/include/mbedtls/debug.h):
	  0 No debug
	  1 Error
	  2 State change
	  3 Information
	  4 Verbose

config MBEDTLS_TEST
	bool "Compile internal self test functions"
	depends on MBEDTLS_BUILTIN
	help
	  Enable self test function for the crypto algorithms

config MBEDTLS_INSTALL_PATH
	string "mbedTLS install path"
	depends on MBEDTLS_LIBRARY
	help
	  This option holds the path where the mbedTLS libraries and headers are
	  installed. Make sure this option is properly set when MBEDTLS_LIBRARY
	  is enabled otherwise the build will fail.

config MBEDTLS_ENABLE_HEAP
	bool "Enable global heap for mbed TLS"
	help
	  This option enables the mbedtls to use the heap. This setting must
	  be global so that various applications and libraries in Zephyr do not
	  try to do this themselves as there can be only one heap defined
	  in mbedtls. If this is enabled, then the Zephyr will, during the device
	  startup, initialize the heap automatically.

config MBEDTLS_HEAP_SIZE
	int "Heap size for mbed TLS"
	default 512
	depends on MBEDTLS_ENABLE_HEAP
	help
	  The mbedtls routines will use this heap if enabled.
	  See ext/lib/crypto/mbedtls/include/mbedtls/config.h and
	  MBEDTLS_MEMORY_BUFFER_ALLOC_C option for details. That option is not
	  enabled by default.
	  Default value for the heap size is not set as it depends on the
	  application. For streaming communication with arbitrary (HTTPS)
	  servers on the Internet, 32KB + overheads (up to another 20KB) may
	  be needed. For some dedicated and specific usage of mbedtls API, the
	  1000 bytes might be ok.

config APP_LINK_WITH_MBEDTLS
	bool "Link 'app' with MBEDTLS"
	default y
	help
	  Add MBEDTLS header files to the 'app' include path. It may be
	  disabled if the include paths for MBEDTLS are causing aliasing
	  issues for 'app'.

endif # MBEDTLS