Applying Security Algorithms Using openSSL crypto library

1. Applying security algorithms using openssl crypto library B.C. Sekar HCL Technologies Limited NETWORKING PRODUCTS DIVISION, HCL

6. Symmetric cryptography It uses the same key for encryption and decryption. E.g. DES, 3DES, Blowfish Encrypt using key K Cipher text Sender Decrypt using key K Cipher text Plain text Receiver Send from Sender to Receiver Plain Text

7. Public key cryptography Public key is distributed whereas private key is kept secret. E.g. RSA, DSA Encrypt using B’s public key Cipher text A Decrypt using B’s private key Cipher text Plain text B Send from Sender to Receiver Plain Text

8. Hashing Function Hash Function Message digest Message Eg. a word “Linux conference” becomes EFDD2356. Typical Hash functions have an infinite domain, such as byte streams of arbitrary length and a finite range such as bit sequences of some fixed length.

9. Digital Signatures Hash Function Message digest Encrypt using Sender’s private key Digital Signature Message The message digest which is the hash value is Encrypted and anybody can check the signature using the public key.

11. NETWORKING PRODUCTS DIVISION, HCL Digital Certificates Country Name: State: Locality: Organizational Name: Common Name: E-mail address: Public key Certificate Sign using private key of Self or trusted Certification Authority(CA).

28. Crypto sub-libraries Sub-libraries Blowfish DES DH HMAC RSA SHA-1

30. OpenSSL CLIs …contd $ openssl list-message-digest-commands md2 md4 md5 mdc2 rmd160 sha sha1

42. SSL/TLS Architecture Packet processing in SSL/TLS record protocol layer. Source: www.modssl.org

43. SSL/TLS connection establishment SSL/TLS Connection establishment. Source: www.modssl.org