LibTomCrypt is a fairly comprehensive, modular and portable
cryptographic toolkit that provides developers with a vast array of
well known published block ciphers, one-way hash functions, chaining
modes, pseudo-random number generators, public key cryptography and a
plethora of other routines.  LibTomCrypt has been designed from the
ground up to be very simple to use.  It has a modular and standard API
that allows new ciphers, hashes and PRNGs to be added or removed
without change to the overall end application.  It features easy to
use functions and a complete user manual which has many source snippet
examples.

* Block Ciphers
    * Blowfish
    * XTEA
    * RC5
    * RC6
    * SAFER+
    * Rijndael (aka AES)
    * Twofish
    * SAFER (K64, SK64, K128, SK128)
    * RC2
    * DES, 3DES
    * CAST5
    * Noekeon
    * Skipjack
    * Anubis (with optional tweak as proposed by the developers)
    * Khazad
    * KASUMI
    * SEED
* Chaining Modes
    * ECB
    * CBC
    * OFB
    * CFB
    * CTR
    * IEEE LRW mode
    * F8 Chaining Mode
* One-Way Hash Functions
    * MD2
    * MD4
    * MD5
    * SHA-1
    * SHA-224/256/384/512
    * TIGER-192
    * RIPE-MD 128/160/256/320
    * WHIRLPOOL
* Message Authentication
    * FIPS-198 HMAC (supports all hashes)
    * CMAC, also known as OMAC1 (supports all ciphers)
    * PMAC Authentication
    * F9-MAC
    * Pelican MAC
* Message Encrypt+Authenticate Modes
    * EAX Mode
    * OCB Mode
    * CCM Mode (NIST spec)
    * GCM Mode (IEEE spec)
* Pseudo-Random Number Generators
    * Yarrow (based algorithm)
    * RC4
    * Support for /dev/random, /dev/urandom and the Win32 CSP RNG
    * Fortuna
    * SOBER-128
* Public Key Algorithms
    * RSA (using PKCS #1 v1.5 and v2.1)
    * ECC (EC-DSA X9.62 signatures, X9.63 EC-DH)
          o With fast Fixed Point ECC support as well
          o X9.63 import/export of public keys
    * DSA (Users make their own groups)
    * The math routines are pluggable which means you can use your own
      math provider if you want.
* Other standards
    * PKCS #1 (v1.5 and v2.1 padding)
    * PKCS #5
    * ASN.1 DER