With the evolution of e-business, data security has become very important
for Internet users. The Secure Socket Layer (SSL) protocol ensures that the
transfer of sensitive information over the Internet is secure. SSL protects
information from:
- Internet eavesdropping
- Data theft
- Traffic analysis
- Data modification
- Trojan horse browser /server
One way IMS Connector for Java communicates with IMS Connect is through
TCP/ IP sockets. If IMS Connector for Java uses TCP/ IP, SSL can be used to
secure the TCP/ IP communication between the two entities. The SSL support
provided by IMS Connector for Java, along with the support provided by IMS
Connect, uses a combination of public and private keys along with symmetric
key encryption schemes to achieve client and server authentication, data confidentiality,
and integrity. SSL rests on top of TCP/ IP communication protocol and allows
an SSL-enabled server to authenticate itself to an SSL-enabled client and
vice versa. For an SSL connection between IMS Connector for Java and IMS Connect,
IMS Connector for Java is considered to be the client and IMS Connect is considered
to be the server. Once authentication is complete, the server and client can
establish an encrypted connection that also preserves the integrity of the
data.
For SSL support when running in a WebSphere® environment, IMS Connector
for Java uses the IBM® implementation of Java Secure Socket Extension (IBM JSSE).
The SSL library is included in WebSphere Studio Application Developer
Integration Edition and in WebSphere Application Server.
SSL concepts
Certificate
A
digital certificate is a digital document that validates the identity of the
certificate's owner. A digital certificate contains information about the
individual, such as their name, company, and public key. The certificate is
signed with a digital signature by the Certificate Authority (CA), which is
a trustworthy authority.
Certificate authority
A
Certificate Authority (CA) is a trusted party that creates and issues digital
certificates to users and systems. The CA, as a valid credential, establishes
the foundation of trust in the certificates.
Certificate management
Certificates
and private keys are stored in files called keystores. A keystore is a database
of key material. Keystore information can be grouped into two categories:
key entries and trusted certificate entries. The two entries can be stored
in the same keystore or separately in a keystore and trustore for security
purposes. Keystores and truststores are used by both the SSL client, IMS Connector
for Java, and the SSL server, IMS Connect.
- Keystore
- A keystore holds key entries, such as the private key of the user. For
example, the client IMS Connector for Java.
- Truststore
- A truststore is a keystore that holds only certificates that the user
trusts. An entry should be added to a truststore only if the user makes a
decision to trust that entity. An example of an IMS Connector for Java (client)
truststore entry would be the certificate of the target server, IMS Connect.
For convenience, IMS Connector for Java allows the user
to store key entries and trusted certificate entries in either the keystore
or the truststore. The user may still choose to store them separately. IMS
Connector for Java supports only X.509 certificates and the "JKS" keystore
type on distributed platforms (which include zLinux) and the "JKS" keystore
type or RACF keyrings on OS/390 and z/OS.
SSL process
The SSL protocol consists of server
authentication, client authentication (optional but strongly recommended)
followed by an encrypted conversation. The following scenario steps through
the SSL process.
Server authentication
SSL server
authentication allows a client to confirm a server's identity. SSL-enabled
client software uses standard techniques of public-key cryptography to ensure
that a server's certificate and public ID is valid and that the certificate
and ID was issued from one of the client's list of trusted certificate authorities
(CA).
Client authentication
SSL client authentication
allows a server to confirm a client's identity. Using the same techniques
used for server authentication, SSL-enabled server software verifies that
a client's certificate and public ID is valid and that the certificate and
ID was issued by one of the server's list of trusted certificate authorities
(CA).
SSL handshake
Both the client, IMS Connector
for Java, and the server, IMS Connect, store their certificates and private
keys in keystores. The actual SSL session between IMS Connector for Java and
IMS Connect is established by following a handshake sequence between client
and server. The sequence will vary depending on whether the server is configured
to provide a server certificate or to request a client certificate, and which
cipher suites are being used. A cipher is an encryption algorithm. The SSL
protocol determines how the client and server negotiate the cipher suites
to authenticate one another, to transmit certificates, and to establish session
keys. Some of the algorithms used in cipher suites include:
- DES - Data Encryption Standard
- DSA - Digital Signature Algorithm
- KEA - Key Exchange Algorithm
- MD5 - Message Digest algorithm
- RC2 and RC4 - Rivest encryption ciphers
- RSA - A public key algorithm for both encryption and authentication
- RSA key exchange - A key-exchange for SSL based on the RSA algorithm
- SHA-1 - Secure Hash Algorithm
- SKIPJACK - A classified symmetric-key algorithm implemented in FORTEZZA-compliant
hardware
- Triple-DES - DES applied three times.
SSL 2.0 and SSL 3.0 protocols support overlapping sets of cipher
suites. Administrators can enable or disable any of the supported cipher suites
for both clients and servers. When a particular client and server exchange
information during the SSL handshake, the client and server identify the strongest
enabled cipher suites that they have in common and use one of them
for the SSL session.
Transport Layer Security, Version 1 (TLS V1) is
the successor to SSL 3.0 protocol. IMS Connector for Java only supports
TLS V1. There are no backward compatibility issues.