public String getHelloHash() throws IOException {
		if (!hashChain.helloHashCreated) {
			// Create hello message
			byte[] msg = createHelloMsg();
			// Calculate the SHA256 hash of the created Hello message
			// Use Implicit Hash (SHA-256) and not Negotiated Hash
			sdpHelloHashSent = calculateSHA256Hash(msg, 0, msg.length);
			hashChain.helloHashCreated = true;
		}
		return sdpHelloHashSent;
	}
public String getHelloHash ( ) throws IOException { if ( ! hashChain . helloHashCreated ) { byte [ ] msg = createHelloMsg ( ) ; sdpHelloHashSent = calculateSHA256Hash ( msg , 0 , msg . length ) ; hashChain . helloHashCreated = true ; } return sdpHelloHashSent ; }
@return SHA256 Hash of the Hello message to be included in the SDP See:
draft-zimmermann-avt-zrtp-17 Sections: 4.1, 8.1 & 5.1.2.1