/*      $OpenBSD: uuencode.c,v 1.15 2019/03/10 20:49:24 schwarze Exp $  */
/*      $FreeBSD: uuencode.c,v 1.18 2004/01/22 07:23:35 grehan Exp $    */

/*-
 * Copyright (c) 1983, 1993
 *      The Regents of the University of California.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

/*
 * Encode a file so it can be mailed to a remote system.
 */

#include <sys/stat.h>

#include <netinet/in.h>

#include <err.h>
#include <resolv.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

void encode(void);
void base64_encode(void);
static void __dead usage(void);

FILE *output;
int mode;
char **av;

enum program_mode {
        MODE_ENCODE,
        MODE_B64ENCODE
} pmode;

int
main(int argc, char *argv[])
{
        struct stat sb;
        int base64, ch;
        char *outfile;
        extern char *__progname;
        static const char *optstr[2] = {
                "mo:",
                "o:"
        };

        base64 = 0;
        outfile = NULL;

        pmode = MODE_ENCODE;
        if (strcmp(__progname, "b64encode") == 0) {
                base64 = 1;
                pmode = MODE_B64ENCODE;
        }

        while ((ch = getopt(argc, argv, optstr[pmode])) != -1) {
                switch (ch) {
                case 'm':
                        base64 = 1;
                        break;
                case 'o':
                        outfile = optarg;
                        break;
                default:
                        usage();
                }
        }
        argv += optind;
        argc -= optind;

        if (argc == 2 || outfile) {
                if (pledge("stdio rpath wpath cpath", NULL) == -1)
                        err(1, "pledge");
        } else {
                if (pledge("stdio", NULL) == -1)
                        err(1, "pledge");
        }

        switch(argc) {
        case 2:                 /* optional first argument is input file */
                if (!freopen(*argv, "r", stdin) || fstat(fileno(stdin), &sb))
                        err(1, "%s", *argv);
#define RWX     (S_IRWXU|S_IRWXG|S_IRWXO)
                mode = sb.st_mode & RWX;
                ++argv;
                break;
        case 1:
#define RW      (S_IRUSR|S_IWUSR|S_IRGRP|S_IWGRP|S_IROTH|S_IWOTH)
                mode = RW & ~umask(RW);
                break;
        default:
                usage();
        }

        av = argv;

        if (outfile != NULL) {
                output = fopen(outfile, "w+");
                if (output == NULL)
                        err(1, "unable to open %s for output", outfile);
        } else
                output = stdout;
        if (base64)
                base64_encode();
        else
                encode();
        if (ferror(output))
                errx(1, "write error");
        return 0;
}

/* ENC is the basic 1 character encoding function to make a char printing */
#define ENC(c) ((c) ? ((c) & 077) + ' ': '`')

/*
 * Copy from in to out, encoding in base64 as you go along.
 */
void
base64_encode(void)
{
        /*
         * Output must fit into 80 columns, chunks come in 4, leave 1.
         */
#define GROUPS  ((80 / 4) - 1)
        unsigned char buf[3];
        char buf2[sizeof(buf) * 2 + 1];
        size_t n;
        int rv, sequence;

        sequence = 0;

        fprintf(output, "begin-base64 %o %s\n", mode, *av);
        while ((n = fread(buf, 1, sizeof(buf), stdin))) {
                ++sequence;
                rv = b64_ntop(buf, n, buf2, (sizeof(buf2) / sizeof(buf2[0])));
                if (rv == -1)
                        errx(1, "b64_ntop: error encoding base64");
                fprintf(output, "%s%s", buf2, (sequence % GROUPS) ? "" : "\n");
        }
        if (sequence % GROUPS)
                fprintf(output, "\n");
        fprintf(output, "====\n");
}

/*
 * Copy from in to out, encoding as you go along.
 */
void
encode(void)
{
        int ch, n;
        char *p;
        char buf[80];

        (void)fprintf(output, "begin %o %s\n", mode, *av);
        while ((n = fread(buf, 1, 45, stdin))) {
                ch = ENC(n);
                if (fputc(ch, output) == EOF)
                        break;
                for (p = buf; n > 0; n -= 3, p += 3) {
                        /* Pad with nulls if not a multiple of 3. */
                        if (n < 3) {
                                p[2] = '\0';
                                if (n < 2)
                                        p[1] = '\0';
                        }
                        ch = *p >> 2;
                        ch = ENC(ch);
                        if (fputc(ch, output) == EOF)
                                break;
                        ch = ((*p << 4) & 060) | ((p[1] >> 4) & 017);
                        ch = ENC(ch);
                        if (fputc(ch, output) == EOF)
                                break;
                        ch = ((p[1] << 2) & 074) | ((p[2] >> 6) & 03);
                        ch = ENC(ch);
                        if (fputc(ch, output) == EOF)
                                break;
                        ch = p[2] & 077;
                        ch = ENC(ch);
                        if (fputc(ch, output) == EOF)
                                break;
                }
                if (fputc('\n', output) == EOF)
                        break;
        }
        if (ferror(stdin))
                errx(1, "read error");
        (void)fprintf(output, "%c\nend\n", ENC('\0'));
}

static void __dead
usage(void)
{
        switch (pmode) {
        case MODE_ENCODE:
                (void)fprintf(stderr,
                    "usage: uuencode [-m] [-o output_file] [file] name\n");
                break;
        case MODE_B64ENCODE:
                (void)fprintf(stderr,
                    "usage: b64encode [-o output_file] [file] name\n");
                break;
        }
        exit(1);
}