/* * Routine to convert old style encrypted files into new (1983) format. * * cvcrypt [-r] oldfile newfile * * Prompts for key. * -r option converts from new to old. * */ #include <stdio.h> #define BSIZE 1024 char *getpass(); char iobuf[BSIZE]; char perm[1024]; main(argc, argv) int argc; char *argv[]; { int ninbuf; long count; int fdi, fdo; int reverse = 0; int i; int warning = 0; if((argv[1][0] == '-') && (argv[1][1] == 'r')){ reverse = 1; argc--; argv++; } if (argc != 3){ fprintf(stderr, "Usage: %s [-r] oldfile newfile\n", argv[0]); exit(1); }else{ crinit(getpass("Enter key:"), perm); } fdi = open(argv[1], 0); if(fdi <0){ fprintf(stderr, "Cannot open %s for reading.\n", argv[1]); exit(1); } fdo = open(argv[2], 1); if(fdo != -1){ fprintf(stderr, "File %s already exists.\n", argv[2]); exit(1); } fdo = creat(argv[2], 0666); if(fdo < 0){ fprintf(stderr, "Cannot open %s for writing.\n", argv[2]); exit(1); } count = 0; while(1){ ninbuf = read(fdi, iobuf, BSIZE); if(ninbuf == 0) exit(0); if(ninbuf < 0){ error("crypt: read error.\n"); exit(1); } if(reverse == 0){ ocrblock(perm, iobuf, ninbuf, count); }else{ crblock(perm, iobuf, ninbuf, count); } if(warning == 0){ for(i=0; i<ninbuf; i++){ if((iobuf[i] & 0200) != 0){ warning = 1; fprintf(stderr, "Wrong key or non-ascii file; conversion continued.\n"); break; } } } if(reverse == 0){ crblock(perm, iobuf, ninbuf, count); }else{ ocrblock(perm, iobuf, ninbuf, count); } count += ninbuf; if(write(fdo, iobuf, ninbuf) != ninbuf){ error("crypt: write error.\n"); exit(1); } } } crblock(permp, buf, nchar, startn) char *permp; char *buf; long startn; { register char *p1; int n1; int n2; int n3; register char *t1, *t2, *t3; char *t4; t1 = permp; t2 = &permp[256]; t3 = &permp[512]; t4 = &permp[768]; n1 = startn&0377; n2 = (startn>>8)&0377; p1 = buf; while(nchar--) { n3 = t4[n1]; *p1 = t2[(t3[(t1[(*p1+n3)&0377]+n2)&0377]-n2)&0377]-n3; n1++; if(n1==256){ n1 = 0; n2++; if(n2==256) n2 = 0; } p1++; } } /* * Besides initializing the encryption machine, this routine * returns 0 if the key is null, and 1 if it is non-null. */ crinit(keyp, permp) char *keyp, *permp; { register char *t1, *t2, *t3; char *t4; register i; int ic, k, temp, pf[2]; unsigned random; char buf[13]; long seed; t1 = permp; t2 = &permp[256]; t3 = &permp[512]; t4 = &permp[768]; if(*keyp == 0) return(0); strncpy(buf, keyp, 8); while (*keyp) *keyp++ = '\0'; buf[8] = buf[0]; buf[9] = buf[1]; if (pipe(pf)<0) pf[0] = pf[1] = -1; if (fork()==0) { close(0); close(1); dup(pf[0]); dup(pf[1]); execl("/usr/lib/makekey", "-", 0); execl("/lib/makekey", "-", 0); exit(1); } write(pf[1], buf, 10); if (wait((int *)NULL)==-1 || read(pf[0], buf, 13)!=13) error("crypt: cannot generate key"); close(pf[0]); close(pf[1]); seed = 123; for (i=0; i<13; i++) seed = seed*buf[i] + i; for(i=0;i<256;i++){ t1[i] = i; t3[i] = 0; } for(i=0; i<256; i++) { seed = 5*seed + buf[i%13]; random = seed % 65521; k = 256-1 - i; ic = (random&0377) % (k+1); random >>= 8; temp = t1[k]; t1[k] = t1[ic]; t1[ic] = temp; if(t3[k]!=0) continue; ic = (random&0377) % k; while(t3[ic]!=0) ic = (ic+1) % k; t3[k] = ic; t3[ic] = k; } for(i=0; i<256; i++){ t2[t1[i]&0377] = i; t4[i] = (t1[i] + t3[i]) & 0377; } return(1); } error(s) char *s; { fprintf(stderr, s); } ocrblock(permp, buf, nchar, startn) char *permp; char *buf; long startn; { register char *p1; int n1; int n2; int n3; register char *t1, *t2, *t3; char *t4; t1 = permp; t2 = &permp[256]; t3 = &permp[512]; t4 = &permp[768]; n1 = startn&0377; n2 = (startn>>8)&0377; p1 = buf; while(nchar--) { *p1 = t2[(t3[(t1[(*p1+n1)&0377]+n2)&0377]-n2)&0377]-n1; n1++; if(n1==256){ n1 = 0; n2++; if(n2==256) n2 = 0; } p1++; } }