snobol, 164 bytes

Result

AC

Duration

839ms

Code [DL]

	T = INPUT
	S = INPUT
	OUTPUT = T
F	OUTPUT = T
	K = INPUT
	DIFFER(S,K)	:S(S) F(F)
S 	K = TRIM(K)
H	EQ(SIZE(K),SIZE(TRIM(T)))	:S(T)
	K = K '*'	:S(H)
T	OUTPUT = K
END

stdin

                                     T            
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                            K                     

stdout

                                     T            
                                     T            
                                     T            
                                     T            
                                     T            
                                     T            
                                     T            
                                     T            
                                     T            
                                     T            
                                     T            
                                     T            
                                     T            
                                     T            
                                     T            
                                     T            
                                     T            
                                     T            
                                     T            
                                     T            
                                     T            
                                     T            
                                     T            
                                     T            
                                     T            
                                     T            
                                     T            
                                     T            
                                     T            
                                     T            
                            K*********

stderr

strace