Here is a list of all files with brief descriptions:

bearssl.h
bearssl_aead.h
bearssl_block.h
bearssl_ec.h
bearssl_hash.h
bearssl_hmac.h
bearssl_kdf.h
bearssl_pem.h
bearssl_prf.h
bearssl_rand.h
bearssl_rsa.h
bearssl_ssl.h
bearssl_x509.h