| /* See LICENSE file for copyright and license details. */ |
| #include <sys/stat.h> |
| |
| #include <errno.h> |
| #include <stdio.h> |
| #include <stdlib.h> |
| #include <string.h> |
| |
| #include "util.h" |
| |
| static int mflag = 0; |
| static int oflag = 0; |
| |
| static FILE * |
| parsefile(const char *fname) |
| { |
| struct stat st; |
| int ret; |
| |
| if (!strcmp(fname, "/dev/stdout") || !strcmp(fname, "-")) |
| return stdout; |
| ret = lstat(fname, &st); |
| /* if it is a new file, try to open it */ |
| if (ret < 0 && errno == ENOENT) |
| goto tropen; |
| if (ret < 0) { |
| weprintf("lstat %s:", fname); |
| return NULL; |
| } |
| if (!S_ISREG(st.st_mode)) { |
| weprintf("for safety uudecode operates only on regular files and /dev/stdout\n"); |
| return NULL; |
| } |
| tropen: |
| return fopen(fname, "w"); |
| } |
| |
| static void |
| parseheader(FILE *fp, const char *s, char **header, mode_t *mode, char **fname) |
| { |
| char bufs[PATH_MAX + 18]; /* len header + mode + maxname */ |
| char *p, *q; |
| size_t n; |
| |
| if (!fgets(bufs, sizeof(bufs), fp)) |
| if (ferror(fp)) |
| eprintf("%s: read error:", s); |
| if (bufs[0] == '\0' || feof(fp)) |
| eprintf("empty or nil header string\n"); |
| if (!(p = strchr(bufs, '\n'))) |
| eprintf("header string too long or non-newline terminated file\n"); |
| p = bufs; |
| if (!(q = strchr(p, ' '))) |
| eprintf("malformed mode string in header, expected ' '\n"); |
| *header = bufs; |
| *q++ = '\0'; |
| p = q; |
| /* now header should be null terminated, q points to mode */ |
| if (!(q = strchr(p, ' '))) |
| eprintf("malformed mode string in header, expected ' '\n"); |
| *q++ = '\0'; |
| /* now mode should be null terminated, q points to fname */ |
| *mode = parsemode(p, *mode, 0); |
| n = strlen(q); |
| while (n > 0 && (q[n - 1] == '\n' || q[n - 1] == '\r')) |
| q[--n] = '\0'; |
| if (n > 0) |
| *fname = q; |
| else |
| eprintf("header string does not contain output file\n"); |
| } |
| |
| static const char b64dt[] = { |
| -1,-1,-1,-1,-1,-1,-1,-1,-1,-2,-2,-2,-2,-2,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1, |
| -1,-1,-1,-1,-1,-1,-1,-1,-2,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,62,-1,-1,-1,63, |
| 52,53,54,55,56,57,58,59,60,61,-1,-1,-1, 0,-1,-1,-1, 0, 1, 2, 3, 4, 5, 6, |
| 7, 8, 9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,-1,-1,-1,-1,-1, |
| -1,26,27,28,29,30,31,32,33,34,35,36,37,38,39,40,41,42,43,44,45,46,47,48, |
| 49,50,51,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1, |
| -1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1, |
| -1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1, |
| -1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1, |
| -1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1, |
| -1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1, |
| }; |
| |
| static void |
| uudecodeb64(FILE *fp, FILE *outfp) |
| { |
| char bufb[60], *pb; |
| char out[45], *po; |
| size_t n; |
| int b = 0, e, t = -1, l = 1; |
| unsigned char b24[3] = {0, 0, 0}; |
| |
| while ((n = fread(bufb, 1, sizeof(bufb), fp))) { |
| for (pb = bufb, po = out; pb < bufb + n; pb++) { |
| if (*pb == '\n') { |
| l++; |
| continue; |
| } else if (*pb == '=') { |
| switch (b) { |
| case 0: |
| /* expected '=' remaining |
| * including footer */ |
| if (--t) { |
| fwrite(out, 1, |
| (po - out), |
| outfp); |
| return; |
| } |
| continue; |
| case 1: |
| eprintf("%d: unexpected \"=\"" |
| "appeared\n", l); |
| case 2: |
| *po++ = b24[0]; |
| b = 0; |
| t = 5; /* expect 5 '=' */ |
| continue; |
| case 3: |
| *po++ = b24[0]; |
| *po++ = b24[1]; |
| b = 0; |
| t = 6; /* expect 6 '=' */ |
| continue; |
| } |
| } else if ((e = b64dt[(int)*pb]) == -1) |
| eprintf("%d: invalid byte \"%c\"\n", l, *pb); |
| else if (e == -2) /* whitespace */ |
| continue; |
| else if (t > 0) /* state is parsing pad/footer */ |
| eprintf("%d: invalid byte \"%c\"" |
| " after padding\n", |
| l, *pb); |
| switch (b) { /* decode next base64 chr based on state */ |
| case 0: b24[0] |= e << 2; break; |
| case 1: b24[0] |= (e >> 4) & 0x3; |
| b24[1] |= (e & 0xf) << 4; break; |
| case 2: b24[1] |= (e >> 2) & 0xf; |
| b24[2] |= (e & 0x3) << 6; break; |
| case 3: b24[2] |= e; break; |
| } |
| if (++b == 4) { /* complete decoding an octet */ |
| *po++ = b24[0]; |
| *po++ = b24[1]; |
| *po++ = b24[2]; |
| b24[0] = b24[1] = b24[2] = 0; |
| b = 0; |
| } |
| } |
| fwrite(out, 1, (po - out), outfp); |
| } |
| eprintf("%d: invalid uudecode footer \"====\" not found\n", l); |
| } |
| |
| static void |
| uudecode(FILE *fp, FILE *outfp) |
| { |
| char *bufb = NULL, *p; |
| size_t n = 0; |
| ssize_t len; |
| int ch, i; |
| |
| #define DEC(c) (((c) - ' ') & 077) /* single character decode */ |
| #define IS_DEC(c) ( (((c) - ' ') >= 0) && (((c) - ' ') <= 077 + 1) ) |
| #define OUT_OF_RANGE(c) eprintf("character %c out of range: [%d-%d]\n", (c), 1 + ' ', 077 + ' ' + 1) |
| |
| while ((len = getline(&bufb, &n, fp)) > 0) { |
| p = bufb; |
| /* trim newlines */ |
| if (!len || bufb[len - 1] != '\n') |
| eprintf("no newline found, aborting\n"); |
| bufb[len - 1] = '\0'; |
| |
| /* check for last line */ |
| if ((i = DEC(*p)) <= 0) |
| break; |
| for (++p; i > 0; p += 4, i -= 3) { |
| if (i >= 3) { |
| if (!(IS_DEC(*p) && IS_DEC(*(p + 1)) && |
| IS_DEC(*(p + 2)) && IS_DEC(*(p + 3)))) |
| OUT_OF_RANGE(*p); |
| |
| ch = DEC(p[0]) << 2 | DEC(p[1]) >> 4; |
| putc(ch, outfp); |
| ch = DEC(p[1]) << 4 | DEC(p[2]) >> 2; |
| putc(ch, outfp); |
| ch = DEC(p[2]) << 6 | DEC(p[3]); |
| putc(ch, outfp); |
| } else { |
| if (i >= 1) { |
| if (!(IS_DEC(*p) && IS_DEC(*(p + 1)))) |
| OUT_OF_RANGE(*p); |
| |
| ch = DEC(p[0]) << 2 | DEC(p[1]) >> 4; |
| putc(ch, outfp); |
| } |
| if (i >= 2) { |
| if (!(IS_DEC(*(p + 1)) && |
| IS_DEC(*(p + 2)))) |
| OUT_OF_RANGE(*p); |
| |
| ch = DEC(p[1]) << 4 | DEC(p[2]) >> 2; |
| putc(ch, outfp); |
| } |
| } |
| } |
| if (ferror(fp)) |
| eprintf("read error:"); |
| } |
| /* check for end or fail */ |
| if ((len = getline(&bufb, &n, fp)) < 0) |
| eprintf("getline:"); |
| if (len < 3 || strncmp(bufb, "end", 3) || bufb[3] != '\n') |
| eprintf("invalid uudecode footer \"end\" not found\n"); |
| free(bufb); |
| } |
| |
| static void |
| usage(void) |
| { |
| eprintf("usage: %s [-m] [-o output] [file]\n", argv0); |
| } |
| |
| int |
| main(int argc, char *argv[]) |
| { |
| FILE *fp = NULL, *nfp = NULL; |
| mode_t mode = 0; |
| int ret = 0; |
| char *fname, *header, *ifname, *ofname = NULL; |
| void (*d) (FILE *, FILE *) = NULL; |
| |
| ARGBEGIN { |
| case 'm': |
| mflag = 1; /* accepted but unused (autodetect file type) */ |
| break; |
| case 'o': |
| oflag = 1; |
| ofname = EARGF(usage()); |
| break; |
| default: |
| usage(); |
| } ARGEND |
| |
| if (argc > 1) |
| usage(); |
| |
| if (!argc || !strcmp(argv[0], "-")) { |
| fp = stdin; |
| ifname = "<stdin>"; |
| } else { |
| if (!(fp = fopen(argv[0], "r"))) |
| eprintf("fopen %s:", argv[0]); |
| ifname = argv[0]; |
| } |
| |
| parseheader(fp, ifname, &header, &mode, &fname); |
| |
| if (!strncmp(header, "begin", sizeof("begin"))) |
| d = uudecode; |
| else if (!strncmp(header, "begin-base64", sizeof("begin-base64"))) |
| d = uudecodeb64; |
| else |
| eprintf("unknown header %s:", header); |
| |
| if (oflag) |
| fname = ofname; |
| if (!(nfp = parsefile(fname))) |
| eprintf("fopen %s:", fname); |
| |
| d(fp, nfp); |
| |
| if (nfp != stdout && chmod(fname, mode) < 0) |
| eprintf("chmod %s:", fname); |
| |
| ret |= fshut(fp, (fp == stdin) ? "<stdin>" : argv[0]); |
| ret |= fshut(nfp, (nfp == stdout) ? "<stdout>" : fname); |
| |
| return ret; |
| } |