1/* 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** ******************************************************************** 7*/ 8 9/* 10** To use MD4: 11** -- Include md4.h in your program 12** -- Declare an MDstruct MD to hold the state of the digest 13** computation. 14** -- Initialize MD using MDbegin(&MD) 15** -- For each full block (64 bytes) X you wish to process, call 16** MD4Update(&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, 19** MD4Update(&MD,X,n) 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 23** has n = 0. 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) 28*/ 29 30/* Implementation notes: 31** This implementation assumes that ints are 32-bit quantities. 32*/ 33 34#define TRUE 1 35#define FALSE 0 36 37/* Compile-time includes 38*/ 39#include <stdio.h> 40#include "md4.h" 41#include "pppd.h" 42 43/* Compile-time declarations of MD4 "magic constants". 44*/ 45#define I0 0x67452301 /* Initial values for MD buffer */ 46#define I1 0xefcdab89 47#define I2 0x98badcfe 48#define I3 0x10325476 49#define C2 013240474631 /* round 2 constant = sqrt(2) in octal */ 50#define C3 015666365641 /* round 3 constant = sqrt(3) in octal */ 51/* C2 and C3 are from Knuth, The Art of Programming, Volume 2 52** (Seminumerical Algorithms), Second Edition (1981), Addison-Wesley. 53** Table 2, page 660. 54*/ 55 56#define fs1 3 /* round 1 shift amounts */ 57#define fs2 7 58#define fs3 11 59#define fs4 19 60#define gs1 3 /* round 2 shift amounts */ 61#define gs2 5 62#define gs3 9 63#define gs4 13 64#define hs1 3 /* round 3 shift amounts */ 65#define hs2 9 66#define hs3 11 67#define hs4 15 68 69/* Compile-time macro declarations for MD4. 70** Note: The "rot" operator uses the variable "tmp". 71** It assumes tmp is declared as unsigned int, so that the >> 72** operator will shift in zeros rather than extending the sign bit. 73*/ 74#define f(X,Y,Z) ((X&Y) | ((~X)&Z)) 75#define g(X,Y,Z) ((X&Y) | (X&Z) | (Y&Z)) 76#define h(X,Y,Z) (X^Y^Z) 77#define rot(X,S) (tmp=X,(tmp<<S) | (tmp>>(32-S))) 78#define ff(A,B,C,D,i,s) A = rot((A + f(B,C,D) + X[i]),s) 79#define gg(A,B,C,D,i,s) A = rot((A + g(B,C,D) + X[i] + C2),s) 80#define hh(A,B,C,D,i,s) A = rot((A + h(B,C,D) + X[i] + C3),s) 81 82/* MD4print(MDp) 83** Print message digest buffer MDp as 32 hexadecimal digits. 84** Order is from low-order byte of buffer[0] to high-order byte of 85** buffer[3]. 86** Each byte is printed with high-order hexadecimal digit first. 87** This is a user-callable routine. 88*/ 89void 90MD4Print(MDp) 91MD4_CTX *MDp; 92{ 93 int i,j; 94 for (i=0;i<4;i++) 95 for (j=0;j<32;j=j+8) 96 printf("%02x",(MDp->buffer[i]>>j) & 0xFF); 97} 98 99/* MD4Init(MDp) 100** Initialize message digest buffer MDp. 101** This is a user-callable routine. 102*/ 103void 104MD4Init(MDp) 105MD4_CTX *MDp; 106{ 107 int i; 108 MDp->buffer[0] = I0; 109 MDp->buffer[1] = I1; 110 MDp->buffer[2] = I2; 111 MDp->buffer[3] = I3; 112 for (i=0;i<8;i++) MDp->count[i] = 0; 113 MDp->done = 0; 114} 115 116/* MDblock(MDp,X) 117** Update message digest buffer MDp->buffer using 16-word data block X. 118** Assumes all 16 words of X are full of data. 119** Does not update MDp->count. 120** This routine is not user-callable. 121*/ 122static void 123MDblock(MDp,Xb) 124MD4_CTX *MDp; 125unsigned char *Xb; 126{ 127 register unsigned int tmp, A, B, C, D; 128 unsigned int X[16]; 129 int i; 130 131 for (i = 0; i < 16; ++i) { 132 X[i] = Xb[0] + (Xb[1] << 8) + (Xb[2] << 16) + (Xb[3] << 24); 133 Xb += 4; 134 } 135 136 A = MDp->buffer[0]; 137 B = MDp->buffer[1]; 138 C = MDp->buffer[2]; 139 D = MDp->buffer[3]; 140 /* Update the message digest buffer */ 141 ff(A , B , C , D , 0 , fs1); /* Round 1 */ 142 ff(D , A , B , C , 1 , fs2); 143 ff(C , D , A , B , 2 , fs3); 144 ff(B , C , D , A , 3 , fs4); 145 ff(A , B , C , D , 4 , fs1); 146 ff(D , A , B , C , 5 , fs2); 147 ff(C , D , A , B , 6 , fs3); 148 ff(B , C , D , A , 7 , fs4); 149 ff(A , B , C , D , 8 , fs1); 150 ff(D , A , B , C , 9 , fs2); 151 ff(C , D , A , B , 10 , fs3); 152 ff(B , C , D , A , 11 , fs4); 153 ff(A , B , C , D , 12 , fs1); 154 ff(D , A , B , C , 13 , fs2); 155 ff(C , D , A , B , 14 , fs3); 156 ff(B , C , D , A , 15 , fs4); 157 gg(A , B , C , D , 0 , gs1); /* Round 2 */ 158 gg(D , A , B , C , 4 , gs2); 159 gg(C , D , A , B , 8 , gs3); 160 gg(B , C , D , A , 12 , gs4); 161 gg(A , B , C , D , 1 , gs1); 162 gg(D , A , B , C , 5 , gs2); 163 gg(C , D , A , B , 9 , gs3); 164 gg(B , C , D , A , 13 , gs4); 165 gg(A , B , C , D , 2 , gs1); 166 gg(D , A , B , C , 6 , gs2); 167 gg(C , D , A , B , 10 , gs3); 168 gg(B , C , D , A , 14 , gs4); 169 gg(A , B , C , D , 3 , gs1); 170 gg(D , A , B , C , 7 , gs2); 171 gg(C , D , A , B , 11 , gs3); 172 gg(B , C , D , A , 15 , gs4); 173 hh(A , B , C , D , 0 , hs1); /* Round 3 */ 174 hh(D , A , B , C , 8 , hs2); 175 hh(C , D , A , B , 4 , hs3); 176 hh(B , C , D , A , 12 , hs4); 177 hh(A , B , C , D , 2 , hs1); 178 hh(D , A , B , C , 10 , hs2); 179 hh(C , D , A , B , 6 , hs3); 180 hh(B , C , D , A , 14 , hs4); 181 hh(A , B , C , D , 1 , hs1); 182 hh(D , A , B , C , 9 , hs2); 183 hh(C , D , A , B , 5 , hs3); 184 hh(B , C , D , A , 13 , hs4); 185 hh(A , B , C , D , 3 , hs1); 186 hh(D , A , B , C , 11 , hs2); 187 hh(C , D , A , B , 7 , hs3); 188 hh(B , C , D , A , 15 , hs4); 189 MDp->buffer[0] += A; 190 MDp->buffer[1] += B; 191 MDp->buffer[2] += C; 192 MDp->buffer[3] += D; 193} 194 195/* MD4Update(MDp,X,count) 196** Input: X -- a pointer to an array of unsigned characters. 197** count -- the number of bits of X to use. 198** (if not a multiple of 8, uses high bits of last byte.) 199** Update MDp using the number of bits of X given by count. 200** This is the basic input routine for an MD4 user. 201** The routine completes the MD computation when count < 512, so 202** every MD computation should end with one call to MD4Update with a 203** count less than 512. A call with count 0 will be ignored if the 204** MD has already been terminated (done != 0), so an extra call with 205** count 0 can be given as a "courtesy close" to force termination 206** if desired. 207*/ 208void 209MD4Update(MDp,X,count) 210MD4_CTX *MDp; 211unsigned char *X; 212unsigned int count; 213{ 214 unsigned int i, tmp, bit, byte, mask; 215 unsigned char XX[64]; 216 unsigned char *p; 217 218 /* return with no error if this is a courtesy close with count 219 ** zero and MDp->done is true. 220 */ 221 if (count == 0 && MDp->done) return; 222 /* check to see if MD is already done and report error */ 223 if (MDp->done) 224 { printf("\nError: MD4Update MD already done."); return; } 225 226 /* Add count to MDp->count */ 227 tmp = count; 228 p = MDp->count; 229 while (tmp) 230 { tmp += *p; 231 *p++ = tmp; 232 tmp = tmp >> 8; 233 } 234 235 /* Process data */ 236 if (count == 512) 237 { /* Full block of data to handle */ 238 MDblock(MDp,X); 239 } 240 else if (count > 512) /* Check for count too large */ 241 { 242 printf("\nError: MD4Update called with illegal count value %d.", 243 count); 244 return; 245 } 246 else /* partial block -- must be last block so finish up */ 247 { 248 /* Find out how many bytes and residual bits there are */ 249 byte = count >> 3; 250 bit = count & 7; 251 /* Copy X into XX since we need to modify it */ 252 for (i=0;i<=byte;i++) XX[i] = X[i]; 253 for (i=byte+1;i<64;i++) XX[i] = 0; 254 /* Add padding '1' bit and low-order zeros in last byte */ 255 mask = 1 << (7 - bit); 256 XX[byte] = (XX[byte] | mask) & ~( mask - 1); 257 /* If room for bit count, finish up with this block */ 258 if (byte <= 55) 259 { 260 for (i=0;i<8;i++) XX[56+i] = MDp->count[i]; 261 MDblock(MDp,XX); 262 } 263 else /* need to do two blocks to finish up */ 264 { 265 MDblock(MDp,XX); 266 for (i=0;i<56;i++) XX[i] = 0; 267 for (i=0;i<8;i++) XX[56+i] = MDp->count[i]; 268 MDblock(MDp,XX); 269 } 270 /* Set flag saying we're done with MD computation */ 271 MDp->done = 1; 272 } 273} 274 275/* 276** Finish up MD4 computation and return message digest. 277*/ 278void 279MD4Final(buf, MD) 280unsigned char *buf; 281MD4_CTX *MD; 282{ 283 int i, j; 284 unsigned int w; 285 286 MD4Update(MD, NULL, 0); 287 for (i = 0; i < 4; ++i) { 288 w = MD->buffer[i]; 289 for (j = 0; j < 4; ++j) { 290 *buf++ = w; 291 w >>= 8; 292 } 293 } 294} 295 296/* 297** End of md4.c 298****************************(cut)***********************************/ 299