2 ** ********************************************************************
3 ** md4.c -- Implementation of MD4 Message Digest Algorithm **
4 ** Updated: 2/16/90 by Ronald L. Rivest **
5 ** (C) 1990 RSA Data Security, Inc. **
6 ** ********************************************************************
11 ** -- Include md4.h in your program
12 ** -- Declare an MDstruct MD to hold the state of the digest
14 ** -- Initialize MD using MDbegin(&MD)
15 ** -- For each full block (64 bytes) X you wish to process, call
16 ** MDupdate(&MD,X,512)
17 ** (512 is the number of bits in a full block.)
18 ** -- For the last block (less than 64 bytes) you wish to process,
20 ** where n is the number of bits in the partial block. A partial
21 ** block terminates the computation, so every MD computation
22 ** should terminate by processing a partial block, even if it
24 ** -- The message digest is available in MD.buffer[0] ...
25 ** MD.buffer[3]. (Least-significant byte of each word
26 ** should be output first.)
27 ** -- You can print out the digest using MDprint(&MD)
30 /* Implementation notes:
31 ** This implementation assumes that ints are 32-bit quantities.
32 ** If the machine stores the least-significant byte of an int in the
33 ** least-addressed byte (e.g., VAX and 8086), then LOWBYTEFIRST
34 ** should be set to TRUE. Otherwise (e.g., SUNS), LOWBYTEFIRST
35 ** should be set to FALSE. Note that on machines with LOWBYTEFIRST
36 ** FALSE the routine MDupdate modifies has a side-effect on its input
37 ** array (the order of bytes in each word are reversed). If this is
38 ** undesired a call to MDreverse(X) can reverse the bytes of X back
39 ** into order after each call to MDupdate.
41 ** NOTE: LOWBYTEFIRST removed by Eric Rosenquist in favour of run-time
42 ** detection to simplify build process.
48 /* Compile-time includes
54 /* Compile-time declarations of MD4 "magic constants".
56 #define I0 0x67452301 /* Initial values for MD buffer */
60 #define C2 013240474631 /* round 2 constant = sqrt(2) in octal */
61 #define C3 015666365641 /* round 3 constant = sqrt(3) in octal */
62 /* C2 and C3 are from Knuth, The Art of Programming, Volume 2
63 ** (Seminumerical Algorithms), Second Edition (1981), Addison-Wesley.
67 #define fs1 3 /* round 1 shift amounts */
71 #define gs1 3 /* round 2 shift amounts */
75 #define hs1 3 /* round 3 shift amounts */
80 /* Compile-time macro declarations for MD4.
81 ** Note: The "rot" operator uses the variable "tmp".
82 ** It assumes tmp is declared as unsigned int, so that the >>
83 ** operator will shift in zeros rather than extending the sign bit.
85 #define f(X,Y,Z) ((X&Y) | ((~X)&Z))
86 #define g(X,Y,Z) ((X&Y) | (X&Z) | (Y&Z))
87 #define h(X,Y,Z) (X^Y^Z)
88 #define rot(X,S) (tmp=X,(tmp<<S) | (tmp>>(32-S)))
89 #define ff(A,B,C,D,i,s) A = rot((A + f(B,C,D) + X[i]),s)
90 #define gg(A,B,C,D,i,s) A = rot((A + g(B,C,D) + X[i] + C2),s)
91 #define hh(A,B,C,D,i,s) A = rot((A + h(B,C,D) + X[i] + C3),s)
94 ** Print message digest buffer MDp as 32 hexadecimal digits.
95 ** Order is from low-order byte of buffer[0] to high-order byte of
97 ** Each byte is printed with high-order hexadecimal digit first.
98 ** This is a user-callable routine.
106 printf("%02x",(MDp->buffer[i]>>j) & 0xFF);
110 ** Initialize message digest buffer MDp.
111 ** This is a user-callable routine.
121 for (i=0;i<8;i++) MDp->count[i] = 0;
126 ** Reverse the byte-ordering of every int in X.
127 ** Assumes X is an array of 16 ints.
128 ** The macro revx reverses the byte-ordering of the next word of X.
130 #define revx { t = (*X << 16) | (*X >> 16); \
131 *X++ = ((t & 0xFF00FF00) >> 8) | ((t & 0x00FF00FF) << 8); }
134 { register unsigned int t;
135 revx; revx; revx; revx; revx; revx; revx; revx;
136 revx; revx; revx; revx; revx; revx; revx; revx;
140 ** Update message digest buffer MDp->buffer using 16-word data block X.
141 ** Assumes all 16 words of X are full of data.
142 ** Does not update MDp->count.
143 ** This routine is not user-callable.
150 register unsigned int tmp, A, B, C, D;
151 static int low_byte_first = -1;
153 if (low_byte_first == -1) {
154 low_byte_first = (htons((unsigned short int)1) != 1);
157 if (low_byte_first == 0) {
165 /* Update the message digest buffer */
166 ff(A , B , C , D , 0 , fs1); /* Round 1 */
167 ff(D , A , B , C , 1 , fs2);
168 ff(C , D , A , B , 2 , fs3);
169 ff(B , C , D , A , 3 , fs4);
170 ff(A , B , C , D , 4 , fs1);
171 ff(D , A , B , C , 5 , fs2);
172 ff(C , D , A , B , 6 , fs3);
173 ff(B , C , D , A , 7 , fs4);
174 ff(A , B , C , D , 8 , fs1);
175 ff(D , A , B , C , 9 , fs2);
176 ff(C , D , A , B , 10 , fs3);
177 ff(B , C , D , A , 11 , fs4);
178 ff(A , B , C , D , 12 , fs1);
179 ff(D , A , B , C , 13 , fs2);
180 ff(C , D , A , B , 14 , fs3);
181 ff(B , C , D , A , 15 , fs4);
182 gg(A , B , C , D , 0 , gs1); /* Round 2 */
183 gg(D , A , B , C , 4 , gs2);
184 gg(C , D , A , B , 8 , gs3);
185 gg(B , C , D , A , 12 , gs4);
186 gg(A , B , C , D , 1 , gs1);
187 gg(D , A , B , C , 5 , gs2);
188 gg(C , D , A , B , 9 , gs3);
189 gg(B , C , D , A , 13 , gs4);
190 gg(A , B , C , D , 2 , gs1);
191 gg(D , A , B , C , 6 , gs2);
192 gg(C , D , A , B , 10 , gs3);
193 gg(B , C , D , A , 14 , gs4);
194 gg(A , B , C , D , 3 , gs1);
195 gg(D , A , B , C , 7 , gs2);
196 gg(C , D , A , B , 11 , gs3);
197 gg(B , C , D , A , 15 , gs4);
198 hh(A , B , C , D , 0 , hs1); /* Round 3 */
199 hh(D , A , B , C , 8 , hs2);
200 hh(C , D , A , B , 4 , hs3);
201 hh(B , C , D , A , 12 , hs4);
202 hh(A , B , C , D , 2 , hs1);
203 hh(D , A , B , C , 10 , hs2);
204 hh(C , D , A , B , 6 , hs3);
205 hh(B , C , D , A , 14 , hs4);
206 hh(A , B , C , D , 1 , hs1);
207 hh(D , A , B , C , 9 , hs2);
208 hh(C , D , A , B , 5 , hs3);
209 hh(B , C , D , A , 13 , hs4);
210 hh(A , B , C , D , 3 , hs1);
211 hh(D , A , B , C , 11 , hs2);
212 hh(C , D , A , B , 7 , hs3);
213 hh(B , C , D , A , 15 , hs4);
220 /* MDupdate(MDp,X,count)
221 ** Input: MDp -- an MDptr
222 ** X -- a pointer to an array of unsigned characters.
223 ** count -- the number of bits of X to use.
224 ** (if not a multiple of 8, uses high bits of last byte.)
225 ** Update MDp using the number of bits of X given by count.
226 ** This is the basic input routine for an MD4 user.
227 ** The routine completes the MD computation when count < 512, so
228 ** every MD computation should end with one call to MDupdate with a
229 ** count less than 512. A call with count 0 will be ignored if the
230 ** MD has already been terminated (done != 0), so an extra call with
231 ** count 0 can be given as a "courtesy close" to force termination
235 MDupdate(MDp,X,count)
239 { unsigned int i, tmp, bit, byte, mask;
240 unsigned char XX[64];
242 /* return with no error if this is a courtesy close with count
243 ** zero and MDp->done is true.
245 if (count == 0 && MDp->done) return;
246 /* check to see if MD is already done and report error */
248 { printf("\nError: MDupdate MD already done."); return; }
249 /* Add count to MDp->count */
259 { /* Full block of data to handle */
260 MDblock(MDp,(unsigned int *)X);
262 else if (count > 512) /* Check for count too large */
263 { printf("\nError: MDupdate called with illegal count value %d."
267 else /* partial block -- must be last block so finish up */
268 { /* Find out how many bytes and residual bits there are */
271 /* Copy X into XX since we need to modify it */
272 for (i=0;i<=byte;i++) XX[i] = X[i];
273 for (i=byte+1;i<64;i++) XX[i] = 0;
274 /* Add padding '1' bit and low-order zeros in last byte */
275 mask = 1 << (7 - bit);
276 XX[byte] = (XX[byte] | mask) & ~( mask - 1);
277 /* If room for bit count, finish up with this block */
279 { for (i=0;i<8;i++) XX[56+i] = MDp->count[i];
280 MDblock(MDp,(unsigned int *)XX);
282 else /* need to do two blocks to finish up */
283 { MDblock(MDp,(unsigned int *)XX);
284 for (i=0;i<56;i++) XX[i] = 0;
285 for (i=0;i<8;i++) XX[56+i] = MDp->count[i];
286 MDblock(MDp,(unsigned int *)XX);
288 /* Set flag saying we're done with MD computation */
295 ****************************(cut)***********************************/