| SSL - SSLv2/v3/v23 etc. | |
| BIO - methods and how they plug together | |
| MEM - memory allocation callback | |
| CRYPTO - locking for threads | |
| EVP - Ciphers/Digests/signatures | |
| RSA - methods | |
| X509 - certificate retrieval | |
| X509 - validation | |
| X509 - X509v3 extensions | |
| Objects - adding object identifiers | |
| ASN.1 - parsing | |
| PEM - parsing | |