According to Wikipedia:
- mbed TLS (previously PolarSSL) is an implementation of the TLS and SSL protocols and the respective cryptographic algorithms and support code required. It is dual-licensed with the Apache License version 2.0 (with GPLv2 also available). Stated on the website is that mbed TLS aims to be "easy to understand, use, integrate and expand".
The command names start with "mbedtls_", for usage examples see the Knowledge Base.
Generate an RSA private key
$ mbedtls_gen_key rsa_keysize=keysize filename=filename
Generate a certificate signing request
$ mbedtls_cert_req filename=private_key subject_name=subject output_file=filename
Generate a self-signed certificate
$ mbedtls_cert_write selfsign=1 issuer_key=private_key issuer_name=subject not_before=YYYYMMDDHHMMSS not_after=YYYYMMDDHHMMSS is_ca=1 max_pathlen=0 output_file=file