As3 Crypto is a cryptography library written in Actionscript 3 that provides several common algorithms. This version also introduces a TLS engine (TLS is commonly known as SSL.)

• Protocols: TLS 1.0 support (partial)
• Certificates: X.509 Certificate parsing and validation, built-in Root CAs.
• Public Key Encryption: RSA (encrypt/decrypt, sign/verify)
• Secret Key Encryption: AES, DES, 3DES, BlowFish, XTEA, RC4
• Confidentiality Modes: ECB, CBC, CFB, CFB8, OFB, CTR
• Hashing Algorithms: MD2, MD5, SHA-1, SHA-224, SHA-256
• Paddings available: PKCS#5, PKCS#1 type 1 and 2
• Other Useful Stuff: HMAC, Random, TLS-PRF, some ASN-1/DER parsing

The library is offered under the BSD license, and include several derivative works from Java, C and javascript sources. Check the LICENSE.txt file for a list of contributors.

You can look at a working demo of the functionality of the library. It's built with Flex 3. It includes a text encrypt and decrypt tab.