This directory contains example configuration files. The examples are generally focused on a particular usage case (eg, support for a restricted number of ciphersuites) and aim at minimizing resource usage for this target. They can be used as a basis for custom configurations. These files are complete replacements for the default config.h. To use one of them, you can pick one of the following methods: 1. Replace the default file include/mbedtls/config.h with the chosen one. (Depending on your compiler, you may need to adjust the line with #include "mbedtls/check_config.h" then.) 2. Define MBEDTLS_CONFIG_FILE and adjust the include path accordingly. For example, using make: CFLAGS="-I$PWD/configs -DMBEDTLS_CONFIG_FILE='<foo.h>'" make Or, using cmake: find . -iname '*cmake*' -not -name CMakeLists.txt -exec rm -rf {} + CFLAGS="-I$PWD/configs -DMBEDTLS_CONFIG_FILE='<foo.h>'" cmake . make Note that the second method also works if you want to keep your custom configuration file outside the mbed TLS tree.