There are some very nice Open-Source Crypto Libraries in the world. They are:

C/C++ Libraries 

• OpenSSL
• Botan
• Cryptlib
• Crypto++
• MatrixSSL
  http://www.matrixssl.org/
• Netscape/Mozilla Network Security Services (NSS)  http://www.mozilla.org/projects/security/pki/nss/
• GnuTLS 
• GnuPG / libgcrypt 
• libTom / libTomCrypt

Java Libraries

• Cryptix
• BouncyCastle
  http://www.bouncycastle.org/