Class HashMD5 

java.lang.Object
   |
   +----HashMD5
public class HashMD5
extends Object

NetRand Project

Software Engineering - CS536

University of Wisconsin - Milwaukee

Authors:


File: HashMD5.java

HashMD5 implements the MD5 one-way hash function designed by Ron Rivest

Variable Index

o A
o a
o b
o B
o C
o c
o D
o d
o msgBlock

Constructor Index

o HashMD5()

Method Index

o divideIntoSubBlocks(byte[])
divides the input block into 16 sub-blocks and copies the sub-blocks into the classes input[] byte array
o doHash(byte[])
performs the MD5 hash on a 512-bit input block
o F(int, int, int)
hashing function used during round 1
o FF(int, int, int, int, int, int, int)
o G(int, int, int)
hashing function used during round 2
o GG(int, int, int, int, int, int, int)
o H(int, int, int)
hashing function used during round 3
o HH(int, int, int, int, int, int, int)
o I(int, int, int)
hashing function used during round 4
o II(int, int, int, int, int, int, int)
o initHashMD5()
initializes the chainging variables before hash is performed
o leftCirShift(int, int)
performed a left circle shift on a 32-bit integer value
o numberOutputBytes()
o requiredInputBytes()
o RoundFour()
round 4 of 4
o RoundOne()
round 1 of 4
o RoundThree()
round 3 of 4
o RoundTwo()
round 2 of 4

Variables

o msgBlock 
 private static int msgBlock[]
o A 
 private static int A
o B 
 private static int B
o C 
 private static int C
o D 
 private static int D
o a 
 private static int a
o b 
 private static int b
o c 
 private static int c
o d 
 private static int d

Constructors

o HashMD5 
 public HashMD5()

Methods

o initHashMD5 
 private static void initHashMD5()
initializes the chainging variables before hash is performed

o requiredInputBytes 
 public static int requiredInputBytes()
Returns:
the number of bytes the MD5 hash function takes as input = 64
o numberOutputBytes 
 public static int numberOutputBytes()
Returns:
the number of bytes the MD5 hash function outputs = 16
o doHash 
 public static byte[] doHash(byte block[]) throws IllegalArgumentException
performs the MD5 hash on a 512-bit input block

Parameters:
block - - the input block to hash
Returns:
128-bit hash value of the input block
Throws: IllegalArgumentException
if the input block size != 512-bits
o divideIntoSubBlocks 
 private static boolean divideIntoSubBlocks(byte block[])
divides the input block into 16 sub-blocks and copies the sub-blocks into the classes input[] byte array

Parameters:
block - - the input block to hash
Returns:
true iff the input block has been divided into sub-blocks, otherwise false is returned
o RoundOne 
 private static void RoundOne()
round 1 of 4

o RoundTwo 
 private static void RoundTwo()
round 2 of 4

o RoundThree 
 private static void RoundThree()
round 3 of 4

o RoundFour 
 private static void RoundFour()
round 4 of 4

o F 
 private static int F(int X,
                      int Y,
                      int Z)
hashing function used during round 1

o FF 
 private static int FF(int a,
                       int b,
                       int c,
                       int d,
                       int M,
                       int s,
                       int constant)
o G 
 private static int G(int X,
                      int Y,
                      int Z)
hashing function used during round 2

o GG 
 private static int GG(int a,
                       int b,
                       int c,
                       int d,
                       int M,
                       int s,
                       int constant)
o H 
 private static int H(int X,
                      int Y,
                      int Z)
hashing function used during round 3

o HH 
 private static int HH(int a,
                       int b,
                       int c,
                       int d,
                       int M,
                       int s,
                       int constant)
o I 
 private static int I(int X,
                      int Y,
                      int Z)
hashing function used during round 4

o II 
 private static int II(int a,
                       int b,
                       int c,
                       int d,
                       int M,
                       int s,
                       int constant)
o leftCirShift 
 private static int leftCirShift(int num,
                                 int nshift)
performed a left circle shift on a 32-bit integer value

Parameters:
num - - the integer value to perform the shift on
nshift - - the number of circle shifts to perform
Returns:
the resulting integer value after the shit is performed