Endo-hyaluronidase that degrades hyaluronan to smaller oligosaccharide fragments. Has also chondroitin sulfate hydrolase activity, The best substrate being the galactosaminidic linkage in the sequence of a trisulfated tetrasaccharide (By similarity). Random hydrolysis of (1->4)-linkages between N-acetyl-beta-D-glucosamine and D-glucuronate residues in hyaluronate. Belongs to the glycosyl hydrolase 56 family.