base64.h | base64 functions |

bio.h | BIO abstracts over a file-descriptor like interface |

buf.h | Memory and string functions, see also mem.h |

bytestring.h | Bytestrings are used for parsing and building TLS and ASN.1 messages |

err.h | Error queue handling functions |

cpu.h | Runtime CPU feature support |

crypto.h | crypto.h contains functions for initializing the crypto library |

ex_data.h | ex_data is a mechanism for associating arbitrary extra data with objects |

lhash.h | lhash is a traditional, chaining hash table that automatically expands and contracts as needed |

mem.h | Memory and string functions, see also buf.h |

obj.h | The objects library deals with the registration and indexing of ASN.1 object identifiers |

pool.h | Buffers and buffer pools |

rand.h | Random number generation |

stack.h | A stack, in OpenSSL, is an array of pointers |

aes.h | Raw AES functions |

bn.h | BN provides support for working with arbitrary sized integers |

chacha.h | ChaCha20 |

cmac.h | CMAC |

curve25519.h | Curve25519 |

des.h | DES |

dh.h | DH contains functions for performing Diffie-Hellman key agreement in multiplicative groups |

dsa.h | DSA contains functions for signing and verifying with the Digital Signature Algorithm |

ec.h | Low-level operations on elliptic curves |

ec_key.h | ec_key.h contains functions that handle elliptic-curve points that are public/private keys |

ecdh.h | Elliptic curve Diffie-Hellman |

ecdsa.h | ECDSA contains functions for signing and verifying with the Digital Signature Algorithm over elliptic curves |

engine.h | Engines are collections of methods |

hkdf.h | HKDF |

hmac.h | HMAC contains functions for constructing PRFs from Merkle–Damgård hash functions using HMAC |

md5.h | MD5 |

rc4.h | RC4 |

rsa.h | rsa.h contains functions for handling encryption and signature using RSA |

sha.h | The SHA family of hash functions (SHA-1 and SHA-2) |

siphash.h | SipHash is a fast, secure PRF that is often used for hash tables |

digest.h | Digest functions |

cipher.h | Ciphers |

aead.h | Authenticated Encryption with Additional Data |

evp.h | EVP abstracts over public/private key algorithms |

ssl.h | SSL implementation |