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/* des: duplicate the NBS Data Encryption Standard in software. * usage: des* prompts for the password * If the filename ends in ".n" it will be decrypted with the key; * otherwise it will be encrypted. * * Permutation algorithm: * The permutation is defined by its effect on each of the 16 nibbles * of the 64-bit input. For each nibble we give an 8-byte bit array * that has the bits in the input nibble distributed correctly. The * complete permutation involves ORing the 16 sets of 8 bytes designated * by the 16 input nibbles. Uses 16*16*8 = 2K bytes of storage for * each 64-bit permutation. 32-bit permutations (P) and expansion (E) * are done similarly, but using bytes instead of nibbles. * Should be able to use long ints, adding the masks, at a * later pass. Tradeoff: can speed 64-bit perms up at cost of slowing * down expansion or contraction operations by using 8K tables here and * decreasing the size of the other tables. * The compressions are pre-computed in 12-bit chunks, combining 2 of the * 6->4 bit compressions. * The key schedule is also precomputed. * Compile with VALIDATE defined to run the NBS validation suite. * * Jim Gillogly, May 1977 * Modified 8/84 by Jim Gillogly and Lauren Weinstein to compile with * post-1977 C compilers and systems * * This program is now officially in the public domain, and is available for * any non-profit use as long as the authorship line is retained. */ /*#define VALIDATE */ /* define to check the NBS validation suite */ /*#define DEBUG */ /*#define LATTICE */ /* define for Lattice C on IBM PC */ #include #ifndef LATTICE #include #include #include /* for local timer */ #include /* ditto */ struct sgttyb ttybuf; /* for gtty/stty */ int bye(); /* for caught interrupts */ #endif char iperm[16][16][8],fperm[16][16][8]; /* inital and final permutations*/ char s[4][4096]; /* S1 thru S8 precomputed */ char p32[4][256][4]; /* for permuting 32-bit f output*/ char kn[16][6]; /* key selections */ endes(inblock,outblock) /* encrypt 64-bit inblock */ char *inblock, *outblock; { char iters[17][8]; /* workspace for each iteration */ char swap[8]; /* place to interchange L and R */ register int i; register char *s, *t; permute(inblock,iperm,iters[0]);/* apply initial permutation */ for (i=0; i<16; i++) /* 16 churning operations */ iter(i,iters[i],iters[i+1]); /* don't re-copy to save space */ s = swap; t = &iters[16][4]; /* interchange left */ *s++ = *t++; *s++ = *t++; *s++ = *t++; *s++ = *t++; t = &iters[16][0]; /* and right */ *s++ = *t++; *s++ = *t++; *s++ = *t++; *s++ = *t++; permute(swap,fperm,outblock); /* apply final permutation */ } dedes(inblock,outblock) /* decrypt 64-bit inblock */ char *inblock,*outblock; { char iters[17][8]; /* workspace for each iteration */ char swap[8]; /* place to interchange L and R */ register int i; register char *s, *t; permute(inblock,iperm,iters[0]);/* apply initial permutation */ for (i=0; i<16; i++) /* 16 churning operations */ iter(15-i,iters[i],iters[i+1]); /* reverse order from encrypting*/ s = swap; t = &iters[16][4]; /* interchange left */ *s++ = *t++; *s++ = *t++; *s++ = *t++; *s++ = *t++; t = &iters[16][0]; /* and right */ *s++ = *t++; *s++ = *t++; *s++ = *t++; *s++ = *t++; permute(swap,fperm,outblock); /* apply final permutation */ } permute(inblock,perm,outblock) /* permute inblock with perm */ char *inblock, *outblock; /* result into outblock,64 bits */ char perm[16][16][8]; /* 2K bytes defining perm. */ { register int i,j; register char *ib, *ob; /* ptr to input or output block */ register char *p, *q; for (i=0, ob = outblock; i<8; i++) *ob++ = 0; /* clear output block */ ib = inblock; for (j = 0; j < 16; j += 2, ib++) /* for each input nibble */ { ob = outblock; p = perm[j][(*ib >> 4) & 017]; q = perm[j + 1][*ib & 017]; for (i = 0; i < 8; i++) /* and each output byte */ *ob++ |= *p++ | *q++; /* OR the masks together*/ } } char ip[] /* initial permutation P */ = { 58, 50, 42, 34, 26, 18, 10, 2, 60, 52, 44, 36, 28, 20, 12, 4, 62, 54, 46, 38, 30, 22, 14, 6, 64, 56, 48, 40, 32, 24, 16, 8, 57, 49, 41, 33, 25, 17, 9, 1, 59, 51, 43, 35, 27, 19, 11, 3, 61, 53, 45, 37, 29, 21, 13, 5, 63, 55, 47, 39, 31, 23, 15, 7 }; char fp[] /* final permutation F */ = { 40, 8, 48, 16, 56, 24, 64, 32, 39, 7, 47, 15, 55, 23, 63, 31, 38, 6, 46, 14, 54, 22, 62, 30, 37, 5, 45, 13, 53, 21, 61, 29, 36, 4, 44, 12, 52, 20, 60, 28, 35, 3, 43, 11, 51, 19, 59, 27, 34, 2, 42, 10, 50, 18, 58, 26, 33, 1, 41, 9, 49, 17, 57, 25 }; /* expansion operation matrix */ /* rwo: unused */ /* char ei[] = { 32, 1, 2, 3, 4, 5, 4, 5, 6, 7, 8, 9, 8, 9, 10, 11, 12, 13, 12, 13, 14, 15, 16, 17, 16, 17, 18, 19, 20, 21, 20, 21, 22, 23, 24, 25, 24, 25, 26, 27, 28, 29, 28, 29, 30, 31, 32, 1 }; */ char pc1[] /* permuted choice table (key) */ = { 57, 49, 41, 33, 25, 17, 9, 1, 58, 50, 42, 34, 26, 18, 10, 2, 59, 51, 43, 35, 27, 19, 11, 3, 60, 52, 44, 36, 63, 55, 47, 39, 31, 23, 15, 7, 62, 54, 46, 38, 30, 22, 14, 6, 61, 53, 45, 37, 29, 21, 13, 5, 28, 20, 12, 4 }; char totrot[] /* number left rotations of pc1 */ = { 1,2,4,6,8,10,12,14,15,17,19,21,23,25,27,28 }; char pc1m[56]; /* place to modify pc1 into */ char pcr[56]; /* place to rotate pc1 into */ char pc2[] /* permuted choice key (table) */ = { 14, 17, 11, 24, 1, 5, 3, 28, 15, 6, 21, 10, 23, 19, 12, 4, 26, 8, 16, 7, 27, 20, 13, 2, 41, 52, 31, 37, 47, 55, 30, 40, 51, 45, 33, 48, 44, 49, 39, 56, 34, 53, 46, 42, 50, 36, 29, 32 }; char si[8][64] /* 48->32 bit compression tables*/ = { /* S[1] */ 14, 4, 13, 1, 2, 15, 11, 8, 3, 10, 6, 12, 5, 9, 0, 7, 0, 15, 7, 4, 14, 2, 13, 1, 10, 6, 12, 11, 9, 5, 3, 8, 4, 1, 14, 8, 13, 6, 2, 11, 15, 12, 9, 7, 3, 10, 5, 0, 15, 12, 8, 2, 4, 9, 1, 7, 5, 11, 3, 14, 10, 0, 6, 13, /* S[2] */ 15, 1, 8, 14, 6, 11, 3, 4, 9, 7, 2, 13, 12, 0, 5, 10, 3, 13, 4, 7, 15, 2, 8, 14, 12, 0, 1, 10, 6, 9, 11, 5, 0, 14, 7, 11, 10, 4, 13, 1, 5, 8, 12, 6, 9, 3, 2, 15, 13, 8, 10, 1, 3, 15, 4, 2, 11, 6, 7, 12, 0, 5, 14, 9, /* S[3] */ 10, 0, 9, 14, 6, 3, 15, 5, 1, 13, 12, 7, 11, 4, 2, 8, 13, 7, 0, 9, 3, 4, 6, 10, 2, 8, 5, 14, 12, 11, 15, 1, 13, 6, 4, 9, 8, 15, 3, 0, 11, 1, 2, 12, 5, 10, 14, 7, 1, 10, 13, 0, 6, 9, 8, 7, 4, 15, 14, 3, 11, 5, 2, 12, /* S[4] */ 7, 13, 14, 3, 0, 6, 9, 10, 1, 2, 8, 5, 11, 12, 4, 15, 13, 8, 11, 5, 6, 15, 0, 3, 4, 7, 2, 12, 1, 10, 14, 9, 10, 6, 9, 0, 12, 11, 7, 13, 15, 1, 3, 14, 5, 2, 8, 4, 3, 15, 0, 6, 10, 1, 13, 8, 9, 4, 5, 11, 12, 7, 2, 14, /* S[5] */ 2, 12, 4, 1, 7, 10, 11, 6, 8, 5, 3, 15, 13, 0, 14, 9, 14, 11, 2, 12, 4, 7, 13, 1, 5, 0, 15, 10, 3, 9, 8, 6, 4, 2, 1, 11, 10, 13, 7, 8, 15, 9, 12, 5, 6, 3, 0, 14, 11, 8, 12, 7, 1, 14, 2, 13, 6, 15, 0, 9, 10, 4, 5, 3, /* S[6] */ 12, 1, 10, 15, 9, 2, 6, 8, 0, 13, 3, 4, 14, 7, 5, 11, 10, 15, 4, 2, 7, 12, 9, 5, 6, 1, 13, 14, 0, 11, 3, 8, 9, 14, 15, 5, 2, 8, 12, 3, 7, 0, 4, 10, 1, 13, 11, 6, 4, 3, 2, 12, 9, 5, 15, 10, 11, 14, 1, 7, 6, 0, 8, 13, /* S[7] */ 4, 11, 2, 14, 15, 0, 8, 13, 3, 12, 9, 7, 5, 10, 6, 1, 13, 0, 11, 7, 4, 9, 1, 10, 14, 3, 5, 12, 2, 15, 8, 6, 1, 4, 11, 13, 12, 3, 7, 14, 10, 15, 6, 8, 0, 5, 9, 2, 6, 11, 13, 8, 1, 4, 10, 7, 9, 5, 0, 15, 14, 2, 3, 12, /* S[8] */ 13, 2, 8, 4, 6, 15, 11, 1, 10, 9, 3, 14, 5, 0, 12, 7, 1, 15, 13, 8, 10, 3, 7, 4, 12, 5, 6, 11, 0, 14, 9, 2, 7, 11, 4, 1, 9, 12, 14, 2, 0, 6, 10, 13, 15, 3, 5, 8, 2, 1, 14, 7, 4, 10, 8, 13, 15, 12, 9, 0, 3, 5, 6, 11 }; char p32i[] /* 32-bit permutation function */ = { 16, 7, 20, 21, 29, 12, 28, 17, 1, 15, 23, 26, 5, 18, 31, 10, 2, 8, 24, 14, 32, 27, 3, 9, 19, 13, 30, 6, 22, 11, 4, 25 }; desinit(key) /* initialize all des arrays */ char *key; { #ifdef DEBUG /*deb*/ printf("Initial perm init.\n"); #endif perminit(iperm,ip); /* initial permutation */ #ifdef DEBUG /*deb*/ printf("Final perm init.\n"); #endif perminit(fperm,fp); /* final permutation */ #ifdef DEBUG /*deb*/ printf("Key sched init.\n"); #endif kinit(key); /* key schedule */ #ifdef DEBUG /*deb*/ printf("Compression init.\n"); #endif sinit(); /* compression functions */ #ifdef DEBUG /*deb*/ printf("32-bit perm init.\n"); #endif p32init(); /* 32-bit permutation in f */ #ifdef DEBUG /*deb*/ printf("End init.\n"); #endif } int bytebit[] /* bit 0 is left-most in byte */ = { 0200,0100,040,020,010,04,02,01 }; int nibblebit[] = { 010,04,02,01 }; sinit() /* initialize s1-s8 arrays */ { register int i,j; for (i=0; i<4; i++) /* each 12-bit position */ for (j=0; j<4096; j++) /* each possible 12-bit value */ s[i][j]=(getcomp(i*2,j>>6)<<4) | (017&getcomp(i*2+1,j&077)); /* store 2 compressions per char*/ } getcomp(k,v) /* 1 compression value for sinit*/ int k,v; { register int i,j; /* correspond to i and j in FIPS*/ i=((v&040)>>4)|(v&1); /* first and last bits make row */ j=(v&037)>>1; /* middle 4 bits are column */ return (int) si[k][(i<<4)+j]; /* result is ith row, jth col */ } kinit(key) /* initialize key schedule array*/ char *key; /* 64 bits (will use only 56) */ { register int i,j,l; int m; for (j=0; j<56; j++) /* convert pc1 to bits of key */ { l=pc1[j]-1; /* integer bit location */ m = l & 07; /* find bit */ pc1m[j]=(key[l>>3] & /* find which key byte l is in */ bytebit[m]) /* and which bit of that byte */ ? 1 : 0; /* and store 1-bit result */ } for (i=0; i<16; i++) /* for each key sched section */ for (j=0; j<6; j++) /* and each byte of the kn */ kn[i][j]=0; /* clear it for accumulation */ for (i=0; i<16; i++) /* key chunk for each iteration */ { for (j=0; j<56; j++) /* rotate pc1 the right amount */ pcr[j] = pc1m[(l=j+totrot[i])<(j<28? 28 : 56) ? l: l-28]; /* rotate left and right halves independently */ for (j=0; j<48; j++) /* select bits individually */ if (pcr[pc2[j]-1]) /* check bit that goes to kn[j] */ { l= j & 07; kn[i][j>>3] |= bytebit[l]; } /* mask it in if it's there */ } } p32init() /* initialize 32-bit permutation*/ { register int l, j, k; int i,m; for (i=0; i<4; i++) /* each input byte position */ for (j=0; j<256; j++) /* all possible input bytes */ for (k=0; k<4; k++) /* each byte of the mask */ p32[i][j][k]=0; /* clear permutation array */ for (i=0; i<4; i++) /* each input byte position */ for (j=0; j<256; j++) /* each possible input byte */ for (k=0; k<32; k++) /* each output bit position */ { l=p32i[k]-1; /* invert this bit (0-31) */ if ((l>>3)!=i) /* does it come from input posn?*/ continue; /* if not, bit k is 0 */ if (!(j&bytebit[l&07])) continue; /* any such bit in input? */ m = k & 07; /* which bit is it? */ p32[i][j][k>>3] |= bytebit[m]; } } perminit(perm,p) /* initialize a perm array */ char perm[16][16][8]; /* 64-bit, either init or final */ char p[64]; { register int l, j, k; int i,m; for (i=0; i<16; i++) /* each input nibble position */ for (j=0; j<16; j++) /* all possible input nibbles */ for (k=0; k<8; k++) /* each byte of the mask */ perm[i][j][k]=0;/* clear permutation array */ for (i=0; i<16; i++) /* each input nibble position */ for (j = 0; j < 16; j++)/* each possible input nibble */ for (k = 0; k < 64; k++)/* each output bit position */ { l = p[k] - 1; /* where does this bit come from*/ if ((l >> 2) != i) /* does it come from input posn?*/ continue; /* if not, bit k is 0 */ if (!(j & nibblebit[l & 3])) continue; /* any such bit in input? */ m = k & 07; /* which bit is this in the byte*/ perm[i][j][k>>3] |= bytebit[m]; } } iter(num,inblock,outblock) /* 1 churning operation */ int num; /* i.e. the num-th one */ char *inblock, *outblock; /* 64 bits each */ { char fret[4]; /* return from f(R[i-1],key) */ register char *ib, *ob, *fb; /* register int i; */ /* rwo: unused */ ob = outblock; ib = &inblock[4]; f(ib, num, fret); /* the primary transformation */ *ob++ = *ib++; /* L[i] = R[i-1] */ *ob++ = *ib++; *ob++ = *ib++; *ob++ = *ib++; ib = inblock; fb = fret; /* R[i]=L[i] XOR f(R[i-1],key) */ *ob++ = *ib++ ^ *fb++; *ob++ = *ib++ ^ *fb++; *ob++ = *ib++ ^ *fb++; *ob++ = *ib++ ^ *fb++; } f(right,num,fret) /* critical cryptographic trans */ char *right, *fret; /* 32 bits each */ int num; /* index number of this iter */ { register char *kb, *rb, *bb; /* ptr to key selection &c */ char bigright[6]; /* right expanded to 48 bits */ char result[6]; /* expand(R) XOR keyselect[num] */ char preout[4]; /* result of 32-bit permutation */ kb = kn[num]; /* fast version of iteration */ bb = bigright; rb = result; expand(right,bb); /* expand to 48 bits */ *rb++ = *bb++ ^ *kb++; /* expanded R XOR chunk of key */ *rb++ = *bb++ ^ *kb++; *rb++ = *bb++ ^ *kb++; *rb++ = *bb++ ^ *kb++; *rb++ = *bb++ ^ *kb++; *rb++ = *bb++ ^ *kb++; contract(result,preout); /* use S fns to get 32 bits */ perm32(preout,fret); /* and do final 32-bit perm */ } perm32(inblock,outblock) /* 32-bit permutation at end */ char *inblock,*outblock; /* of the f crypto function */ { register int j; /* register int i; */ /* rwo: unused */ register char *ib, *ob; register char *q; ob = outblock; /* clear output block */ *ob++ = 0; *ob++ = 0; *ob++ = 0; *ob++ = 0; ib=inblock; /* ptr to 1st byte of input */ for (j=0; j<4; j++, ib++) /* for each input byte */ { q = p32[j][*ib & 0377]; ob = outblock; /* and each output byte */ *ob++ |= *q++; /* OR the 16 masks together */ *ob++ |= *q++; *ob++ |= *q++; *ob++ |= *q++; } } expand(right,bigright) /* 32 to 48 bits with E oper */ char *right,*bigright; /* right is 32, bigright 48 */ { register char *bb, *r, r0, r1, r2, r3; bb = bigright; r = right; r0 = *r++; r1 = *r++; r2 = *r++; r3 = *r++; *bb++ = ((r3 & 0001) << 7) | /* 32 */ ((r0 & 0370) >> 1) | /* 1 2 3 4 5 */ ((r0 & 0030) >> 3); /* 4 5 */ *bb++ = ((r0 & 0007) << 5) | /* 6 7 8 */ ((r1 & 0200) >> 3) | /* 9 */ ((r0 & 0001) << 3) | /* 8 */ ((r1 & 0340) >> 5); /* 9 10 11 */ *bb++ = ((r1 & 0030) << 3) | /* 12 13 */ ((r1 & 0037) << 1) | /* 12 13 14 15 16 */ ((r2 & 0200) >> 7); /* 17 */ *bb++ = ((r1 & 0001) << 7) | /* 16 */ ((r2 & 0370) >> 1) | /* 17 18 19 20 21 */ ((r2 & 0030) >> 3); /* 20 21 */ *bb++ = ((r2 & 0007) << 5) | /* 22 23 24 */ ((r3 & 0200) >> 3) | /* 25 */ ((r2 & 0001) << 3) | /* 24 */ ((r3 & 0340) >> 5); /* 25 26 27 */ *bb++ = ((r3 & 0030) << 3) | /* 28 29 */ ((r3 & 0037) << 1) | /* 28 29 30 31 32 */ ((r0 & 0200) >> 7); /* 1 */ } contract(in48,out32) /* contract f from 48 to 32 bits*/ char *in48,*out32; /* using 12-bit pieces into bytes */ { register char *c; register char *i; register int i0, i1, i2, i3, i4, i5; i = in48; i0 = *i++; i1 = *i++; i2 = *i++; i3 = *i++; i4 = *i++; i5 = *i++; c = out32; /* do output a byte at a time */ *c++ = s[0][07777 & ((i0 << 4) | ((i1 >> 4) & 017 ))]; *c++ = s[1][07777 & ((i1 << 8) | ( i2 & 0377 ))]; *c++ = s[2][07777 & ((i3 << 4) | ((i4 >> 4) & 017 ))]; *c++ = s[3][07777 & ((i4 << 8) | ( i5 & 0377 ))]; } /* End of DES algorithm (except for calling desinit below) */ #ifndef VALIDATE char *inname, *outname; FILE *infile, *outfile; int encrypting; char buf[512]; char keyx[9], keyy[9]; char *malloc(), *strcpy(), *strcat(); main(argc, argv) int argc; char *argv[]; { register char *u; char *filename; if (argc < 2) /* filenames given? */ { fprintf(stderr, "Usage: des file ...\n"); exit(1); } for (++argv; --argc; ++argv) { inname = *argv; outname = filename = malloc((unsigned) strlen(inname) + 3); strcpy(filename, inname); u = &filename[strlen(filename) - 2]; /* check last 2 chars */ encrypting = (strcmp(".n", u) != 0); if (!encrypting) *u = 0; /* strip .n from output filename */ else strcat(filename, ".n"); /* or add .n to output file */ if ((infile = fopen(inname, "rb")) == NULL) { fprintf(stderr,"Can't read %s.\n", inname); exit(1); } if ((outfile = fopen(outname, "rb")) != NULL) { fprintf(stderr, "%s would be overwritten.\n",outname); exit(1); } if ((outfile = fopen(outname, "wb")) == NULL) { fprintf(stderr,"Can't write %s.\n", outname); exit(1); } key_get("Type password for "); for (;;) { strcpy(keyx, keyy); key_get("Verify password for "); if (strcmp(keyx, keyy) == 0) break; } desinit(keyx); /* set up tables for DES */ if (pfile() == 0) unlink(inname); else fprintf(stderr, "%s: I/O Error -- File unchanged\n", inname); fclose(outfile); fclose(infile); } exit(0); } key_get(mes) /* get file key */ char *mes; { register int i, j; char linebuf[256]; int count; for (i=0; i<14; i++) keyy[i]=0; #ifdef LATTICE #else gtty(0, &ttybuf); ttybuf.sg_flags &= ~ECHO; /* turn off echoing */ signal(SIGINT, bye); /* catch ints */ stty(0, &ttybuf); #endif printf("%s%s: ", mes, inname); fflush(stdout); count = read(0, linebuf, 256); /* read input line */ printf("\n"); #ifndef LATTICE ttybuf.sg_flags |= ECHO; /* restore echo */ stty(0, &ttybuf); #endif linebuf[count] = 0; /* null terminate */ if (linebuf[count-1] == '\n') /* ignore any terminating newline */ { linebuf[count-1] = 0; count--; } if (count > 8) count = 8; /* only use 8 chars */ for (i = j = 0; count--;) keyy[i++] = linebuf[j++]; } pfile() /* process the file */ { register int m, nsave; register char *b; int j; while (m = fread(buf, 1, 512, infile)) { if ((nsave = m) < 0) /* read error */ return(-1); for (b=buf; m>0; /* encrypt/decrypt 1 buffer-full*/ m -= 8, b += 8) /* 8-byte blocks */ { if (encrypting) { if (m<8) /* don't have a full 64 bits */ { for (j=0; j<8-m; j++) b[m+j]=garbage(); /* fill block with trash */ nsave += 8-m; /* complete the block */ } else j=0 /* number of nulls in last block*/ endes(b,b); /* don't need diff input, output*/ } else /* decrypting */ { if (m < 8) deout(b, 1); /* last byte in file: count */ else { dedes(b, b); /* decrypt and output block */ deout(b, 0); } } } if (encrypting) if (fwrite(buf, 1, nsave, outfile) != nsave) return(-1); } /* have now encrypted/decrypted the whole file; * need to append the byte count for the last block if encrypting. */ if (encrypting) fputc(8 - j, outfile); /* how many good bytes? */ return(0); } int outcount = 0; /* see when caught up with delay*/ deout(block,flag) /* 1-block delay on output */ char *block,flag; /* 64-bit block, last block flag*/ { static char last[8]; /* previous input block */ register int i; /* register char *c,*j; */ /* rwo: unused */ if (flag) /* output the last few bytes */ { fwrite(last, 1, block[0] & 0377, outfile); return; } if (outcount++) /* seen any blocks before? */ fwrite(last, 1, 8, outfile); for (i = 0; i < 8; i++) last[i] = block[i]; /* copy the block */ } garbage() /* generate garbage for filling */ /* This garbage should be as random as possible. We're using subsequent calls * on the timer, but ideally each byte should be uncorrelated. Preferable * would be to call the timer once and use it to initialize a dumb random * number generator. */ { #ifdef LATTICE long timer(), ltime; ltime = timer(); return (int) ltime & 0377; #else struct timeb tp; ftime(&tp); /* get current time */ return tp.millitm; /* return time in milliseconds */ #endif } #ifndef LATTICE /* restore echo to tty and exit */ bye() { ttybuf.sg_flags |= ECHO; /* restore echoing */ stty(0, &ttybuf); exit(2); } #endif #else /* validation */ #define VALFILE "valid.triples" FILE *fd; char key[8], plain[8], cipher[8], processed[8]; main() /* read key/plain/cipher triples until exhausted */ { int count, i; if ((fd = fopen(VALFILE, "r")) == NULL) { fprintf(stderr, "Can't read %s.\n", VALFILE); exit(1); } count = 0; desinit(key); /* initialize most of the arrays */ while (readvals()) { kinit(key); /* initialize key stuff */ printf("Key: "); writehex(key); printf(" Plain: "); writehex(plain); printf(" Cipher: "); writehex(cipher); printf("\n"); endes(plain, processed); /* encipher the plaintext */ printf("Encry: "); writehex(processed); printf("\n"); for (i = 0; i < 8; i++) if (processed[i] != cipher[i]) printf("Encryption failed.\n"); dedes(cipher, processed); /* decipher the ciphertext */ printf("Decry: "); writehex(processed); printf("\n"); for (i = 0; i < 8; i++) if (processed[i] != plain[i]) printf("Decryption failed.\n"); count++; } printf("Processed %d tests.\n", count); } readvals() /* get the next legit triple */ { int r; r = readhex(key); readhex(plain); readhex(cipher); return r; } writehex(str) /* write the 64-bit hex string */ char *str; { int i; for (i = 0; i < 8; i++) printf("%02x", str[i] & 0377); } hex(n) /* convert hex nibble into integer */ int n; { if (n >= 'A' && n <= 'F') return n - 'A' + 10; return n - '0'; } readhex(str) /* read 64 bits of hex code */ char *str; { int i, c; for (i = 0; i < 8; i++) { c = hex(getc(fd)) << 4; str[i] = c | hex(getc(fd)); } while ((c = getc(fd)) == ' ' || c == '\t' || c == '\n'); ungetc(c, fd); /* skip to next field */ return c != EOF; } #endif /************ end scrydes ************/