question: public BigInteger calculateClientEvidenceMessage ( ) throws CryptoException { if ( ( this . A == null ) || ( this . B == null ) || ( this . S == null ) ) { throw new CryptoException ( "Impossible to compute M1: " + "some data are missing from the previous operations (A,B,S)" ) ; } this . M1 = SRP6Util . calculateM1 ( digest , N , A , B , S ) ; return M1 ; }
target:  Computes the client evidence message M1 using the previously received values. To be called after calculating the secret S.