mirror of
https://github.com/paulusmack/ppp.git
synced 2024-11-30 23:13:35 +08:00
299 lines
8.4 KiB
C
299 lines
8.4 KiB
C
/*
|
|
** ********************************************************************
|
|
** md4.c -- Implementation of MD4 Message Digest Algorithm **
|
|
** Updated: 2/16/90 by Ronald L. Rivest **
|
|
** (C) 1990 RSA Data Security, Inc. **
|
|
** ********************************************************************
|
|
*/
|
|
|
|
/*
|
|
** To use MD4:
|
|
** -- Include md4.h in your program
|
|
** -- Declare an MDstruct MD to hold the state of the digest
|
|
** computation.
|
|
** -- Initialize MD using MDbegin(&MD)
|
|
** -- For each full block (64 bytes) X you wish to process, call
|
|
** MD4Update(&MD,X,512)
|
|
** (512 is the number of bits in a full block.)
|
|
** -- For the last block (less than 64 bytes) you wish to process,
|
|
** MD4Update(&MD,X,n)
|
|
** where n is the number of bits in the partial block. A partial
|
|
** block terminates the computation, so every MD computation
|
|
** should terminate by processing a partial block, even if it
|
|
** has n = 0.
|
|
** -- The message digest is available in MD.buffer[0] ...
|
|
** MD.buffer[3]. (Least-significant byte of each word
|
|
** should be output first.)
|
|
** -- You can print out the digest using MDprint(&MD)
|
|
*/
|
|
|
|
/* Implementation notes:
|
|
** This implementation assumes that ints are 32-bit quantities.
|
|
*/
|
|
|
|
#define TRUE 1
|
|
#define FALSE 0
|
|
|
|
/* Compile-time includes
|
|
*/
|
|
#include <stdio.h>
|
|
#include "md4.h"
|
|
#include "pppd.h"
|
|
|
|
/* Compile-time declarations of MD4 "magic constants".
|
|
*/
|
|
#define I0 0x67452301 /* Initial values for MD buffer */
|
|
#define I1 0xefcdab89
|
|
#define I2 0x98badcfe
|
|
#define I3 0x10325476
|
|
#define C2 013240474631 /* round 2 constant = sqrt(2) in octal */
|
|
#define C3 015666365641 /* round 3 constant = sqrt(3) in octal */
|
|
/* C2 and C3 are from Knuth, The Art of Programming, Volume 2
|
|
** (Seminumerical Algorithms), Second Edition (1981), Addison-Wesley.
|
|
** Table 2, page 660.
|
|
*/
|
|
|
|
#define fs1 3 /* round 1 shift amounts */
|
|
#define fs2 7
|
|
#define fs3 11
|
|
#define fs4 19
|
|
#define gs1 3 /* round 2 shift amounts */
|
|
#define gs2 5
|
|
#define gs3 9
|
|
#define gs4 13
|
|
#define hs1 3 /* round 3 shift amounts */
|
|
#define hs2 9
|
|
#define hs3 11
|
|
#define hs4 15
|
|
|
|
/* Compile-time macro declarations for MD4.
|
|
** Note: The "rot" operator uses the variable "tmp".
|
|
** It assumes tmp is declared as unsigned int, so that the >>
|
|
** operator will shift in zeros rather than extending the sign bit.
|
|
*/
|
|
#define f(X,Y,Z) ((X&Y) | ((~X)&Z))
|
|
#define g(X,Y,Z) ((X&Y) | (X&Z) | (Y&Z))
|
|
#define h(X,Y,Z) (X^Y^Z)
|
|
#define rot(X,S) (tmp=X,(tmp<<S) | (tmp>>(32-S)))
|
|
#define ff(A,B,C,D,i,s) A = rot((A + f(B,C,D) + X[i]),s)
|
|
#define gg(A,B,C,D,i,s) A = rot((A + g(B,C,D) + X[i] + C2),s)
|
|
#define hh(A,B,C,D,i,s) A = rot((A + h(B,C,D) + X[i] + C3),s)
|
|
|
|
/* MD4print(MDp)
|
|
** Print message digest buffer MDp as 32 hexadecimal digits.
|
|
** Order is from low-order byte of buffer[0] to high-order byte of
|
|
** buffer[3].
|
|
** Each byte is printed with high-order hexadecimal digit first.
|
|
** This is a user-callable routine.
|
|
*/
|
|
void
|
|
MD4Print(MDp)
|
|
MD4_CTX *MDp;
|
|
{
|
|
int i,j;
|
|
for (i=0;i<4;i++)
|
|
for (j=0;j<32;j=j+8)
|
|
printf("%02x",(MDp->buffer[i]>>j) & 0xFF);
|
|
}
|
|
|
|
/* MD4Init(MDp)
|
|
** Initialize message digest buffer MDp.
|
|
** This is a user-callable routine.
|
|
*/
|
|
void
|
|
MD4Init(MDp)
|
|
MD4_CTX *MDp;
|
|
{
|
|
int i;
|
|
MDp->buffer[0] = I0;
|
|
MDp->buffer[1] = I1;
|
|
MDp->buffer[2] = I2;
|
|
MDp->buffer[3] = I3;
|
|
for (i=0;i<8;i++) MDp->count[i] = 0;
|
|
MDp->done = 0;
|
|
}
|
|
|
|
/* MDblock(MDp,X)
|
|
** Update message digest buffer MDp->buffer using 16-word data block X.
|
|
** Assumes all 16 words of X are full of data.
|
|
** Does not update MDp->count.
|
|
** This routine is not user-callable.
|
|
*/
|
|
static void
|
|
MDblock(MDp,Xb)
|
|
MD4_CTX *MDp;
|
|
unsigned char *Xb;
|
|
{
|
|
register unsigned int tmp, A, B, C, D;
|
|
unsigned int X[16];
|
|
int i;
|
|
|
|
for (i = 0; i < 16; ++i) {
|
|
X[i] = Xb[0] + (Xb[1] << 8) + (Xb[2] << 16) + (Xb[3] << 24);
|
|
Xb += 4;
|
|
}
|
|
|
|
A = MDp->buffer[0];
|
|
B = MDp->buffer[1];
|
|
C = MDp->buffer[2];
|
|
D = MDp->buffer[3];
|
|
/* Update the message digest buffer */
|
|
ff(A , B , C , D , 0 , fs1); /* Round 1 */
|
|
ff(D , A , B , C , 1 , fs2);
|
|
ff(C , D , A , B , 2 , fs3);
|
|
ff(B , C , D , A , 3 , fs4);
|
|
ff(A , B , C , D , 4 , fs1);
|
|
ff(D , A , B , C , 5 , fs2);
|
|
ff(C , D , A , B , 6 , fs3);
|
|
ff(B , C , D , A , 7 , fs4);
|
|
ff(A , B , C , D , 8 , fs1);
|
|
ff(D , A , B , C , 9 , fs2);
|
|
ff(C , D , A , B , 10 , fs3);
|
|
ff(B , C , D , A , 11 , fs4);
|
|
ff(A , B , C , D , 12 , fs1);
|
|
ff(D , A , B , C , 13 , fs2);
|
|
ff(C , D , A , B , 14 , fs3);
|
|
ff(B , C , D , A , 15 , fs4);
|
|
gg(A , B , C , D , 0 , gs1); /* Round 2 */
|
|
gg(D , A , B , C , 4 , gs2);
|
|
gg(C , D , A , B , 8 , gs3);
|
|
gg(B , C , D , A , 12 , gs4);
|
|
gg(A , B , C , D , 1 , gs1);
|
|
gg(D , A , B , C , 5 , gs2);
|
|
gg(C , D , A , B , 9 , gs3);
|
|
gg(B , C , D , A , 13 , gs4);
|
|
gg(A , B , C , D , 2 , gs1);
|
|
gg(D , A , B , C , 6 , gs2);
|
|
gg(C , D , A , B , 10 , gs3);
|
|
gg(B , C , D , A , 14 , gs4);
|
|
gg(A , B , C , D , 3 , gs1);
|
|
gg(D , A , B , C , 7 , gs2);
|
|
gg(C , D , A , B , 11 , gs3);
|
|
gg(B , C , D , A , 15 , gs4);
|
|
hh(A , B , C , D , 0 , hs1); /* Round 3 */
|
|
hh(D , A , B , C , 8 , hs2);
|
|
hh(C , D , A , B , 4 , hs3);
|
|
hh(B , C , D , A , 12 , hs4);
|
|
hh(A , B , C , D , 2 , hs1);
|
|
hh(D , A , B , C , 10 , hs2);
|
|
hh(C , D , A , B , 6 , hs3);
|
|
hh(B , C , D , A , 14 , hs4);
|
|
hh(A , B , C , D , 1 , hs1);
|
|
hh(D , A , B , C , 9 , hs2);
|
|
hh(C , D , A , B , 5 , hs3);
|
|
hh(B , C , D , A , 13 , hs4);
|
|
hh(A , B , C , D , 3 , hs1);
|
|
hh(D , A , B , C , 11 , hs2);
|
|
hh(C , D , A , B , 7 , hs3);
|
|
hh(B , C , D , A , 15 , hs4);
|
|
MDp->buffer[0] += A;
|
|
MDp->buffer[1] += B;
|
|
MDp->buffer[2] += C;
|
|
MDp->buffer[3] += D;
|
|
}
|
|
|
|
/* MD4Update(MDp,X,count)
|
|
** Input: X -- a pointer to an array of unsigned characters.
|
|
** count -- the number of bits of X to use.
|
|
** (if not a multiple of 8, uses high bits of last byte.)
|
|
** Update MDp using the number of bits of X given by count.
|
|
** This is the basic input routine for an MD4 user.
|
|
** The routine completes the MD computation when count < 512, so
|
|
** every MD computation should end with one call to MD4Update with a
|
|
** count less than 512. A call with count 0 will be ignored if the
|
|
** MD has already been terminated (done != 0), so an extra call with
|
|
** count 0 can be given as a "courtesy close" to force termination
|
|
** if desired.
|
|
*/
|
|
void
|
|
MD4Update(MDp,X,count)
|
|
MD4_CTX *MDp;
|
|
unsigned char *X;
|
|
unsigned int count;
|
|
{
|
|
unsigned int i, tmp, bit, byte, mask;
|
|
unsigned char XX[64];
|
|
unsigned char *p;
|
|
|
|
/* return with no error if this is a courtesy close with count
|
|
** zero and MDp->done is true.
|
|
*/
|
|
if (count == 0 && MDp->done) return;
|
|
/* check to see if MD is already done and report error */
|
|
if (MDp->done)
|
|
{ printf("\nError: MD4Update MD already done."); return; }
|
|
|
|
/* Add count to MDp->count */
|
|
tmp = count;
|
|
p = MDp->count;
|
|
while (tmp)
|
|
{ tmp += *p;
|
|
*p++ = tmp;
|
|
tmp = tmp >> 8;
|
|
}
|
|
|
|
/* Process data */
|
|
if (count == 512)
|
|
{ /* Full block of data to handle */
|
|
MDblock(MDp,X);
|
|
}
|
|
else if (count > 512) /* Check for count too large */
|
|
{
|
|
printf("\nError: MD4Update called with illegal count value %d.",
|
|
count);
|
|
return;
|
|
}
|
|
else /* partial block -- must be last block so finish up */
|
|
{
|
|
/* Find out how many bytes and residual bits there are */
|
|
byte = count >> 3;
|
|
bit = count & 7;
|
|
/* Copy X into XX since we need to modify it */
|
|
for (i=0;i<=byte;i++) XX[i] = X[i];
|
|
for (i=byte+1;i<64;i++) XX[i] = 0;
|
|
/* Add padding '1' bit and low-order zeros in last byte */
|
|
mask = 1 << (7 - bit);
|
|
XX[byte] = (XX[byte] | mask) & ~( mask - 1);
|
|
/* If room for bit count, finish up with this block */
|
|
if (byte <= 55)
|
|
{
|
|
for (i=0;i<8;i++) XX[56+i] = MDp->count[i];
|
|
MDblock(MDp,XX);
|
|
}
|
|
else /* need to do two blocks to finish up */
|
|
{
|
|
MDblock(MDp,XX);
|
|
for (i=0;i<56;i++) XX[i] = 0;
|
|
for (i=0;i<8;i++) XX[56+i] = MDp->count[i];
|
|
MDblock(MDp,XX);
|
|
}
|
|
/* Set flag saying we're done with MD computation */
|
|
MDp->done = 1;
|
|
}
|
|
}
|
|
|
|
/*
|
|
** Finish up MD4 computation and return message digest.
|
|
*/
|
|
void
|
|
MD4Final(buf, MD)
|
|
unsigned char *buf;
|
|
MD4_CTX *MD;
|
|
{
|
|
int i, j;
|
|
unsigned int w;
|
|
|
|
MD4Update(MD, NULL, 0);
|
|
for (i = 0; i < 4; ++i) {
|
|
w = MD->buffer[i];
|
|
for (j = 0; j < 4; ++j) {
|
|
*buf++ = w;
|
|
w >>= 8;
|
|
}
|
|
}
|
|
}
|
|
|
|
/*
|
|
** End of md4.c
|
|
****************************(cut)***********************************/
|