question: public static String keyAlgorithm ( String algorithm ) { int index = algorithm . indexOf ( '_' ) ; if ( index == - 1 ) { return algorithm ; } return algorithm . substring ( 0 , index ) ; }
target:  Return the key algorithm for a possible compound algorithm identifier containing an underscore. If not underscore is present, the argument is returned unmodified. However for an algorithm such as EC_RSA, return EC.