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/* 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)
{
static 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;
}
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