OpenSSL

Note

Please see the talk page for the status of this book. You may wish to visit the OpenSSL Foundation Wiki instead. (aka the OpenSSL wiki).

OpenSSL

OpenSSL is an open-source library for Transport Layer Security and general-purpose Cryptography.

Overview

OpenSSL consists of two separate libraries: libcrypto and libssl. libcrypto is a general-purpose cryptography library which can be used alone. libssl is a TLS library which depends on libcrypto. OpenSSL also comes with an "openssl" command-line program, which can be used to exercise much of the functionality of the library from the command line.

libcrypto

libcrypto is the portion of OpenSSL for performing general-purpose cryptography, which can be used without libssl.

Introduction to libcrypto Initialization Random numbers Error handling Reference counting	BIO Using BIOs Pre-defined BIOs Writing your own BIOs	EVP Digests Symmetric ciphers Signatures Public key	Keys and Certificates PEM ASN.1 X509 OCSP
Elliptic Curve Cryptography Introduction EC_GROUP_new EC_GROUP_copy EC_POINT_new EC_POINT_add EC_KEY_new EC_GFp_simple_method d2i_ECPKParameters	Engines Engine architecture Using engines Supplied engines Writing your own engines	More libcrypto Diffie-Hellman Bignum Windows Configuration

libssl

libssl is the portion of OpenSSL which supports TLS, and depends on libcrypto.

Introduction to libssl Contexts Connections

Configuration Options Cipher suites Diffie-Hellman parameters

Certificate Validation Verify locations Verify callbacks Hostname validation

More libssl Session resumption DTLS Alternative key exchange

command line programs

The "openssl" command line program contains a variety of sub-programs.

TODO: document all of them!

Appendices

FIPS

About the book

Notes for contributors