/*	$NetBSD: digest.c,v 1.11 2005/03/23 21:40:35 yamt Exp $ */

/*
 * Copyright (c) 2001-2005 Alistair G. Crooks.  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. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *	This product includes software developed by Alistair G. Crooks.
 * 4. The name of the author may not be used to endorse or promote
 *    products derived from this software without specific prior written
 *    permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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.
 */
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#include <digest-types.h>

#ifndef lint
__COPYRIGHT("@(#) Copyright (c) 2001-2005 \
	        The NetBSD Foundation, Inc.  All rights reserved.");
__RCSID("$NetBSD: digest.c,v 1.11 2005/03/23 21:40:35 yamt Exp $");
#endif


#include <sys/queue.h>
#include <sys/stat.h>

#ifdef HAVE_ERRNO_H
#include <errno.h>
#endif
#include <fcntl.h>
#include <fts.h>
#ifdef HAVE_LOCALE_H
#include <locale.h>
#endif
#include <md5.h>
#include <rmd160.h>
#include <sha1.h>
#include <sha2.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <tiger.h>
#include <whirlpool.h>
#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif

typedef void (*HASH_init)(void *);
typedef void (*HASH_update)(void *, const unsigned char *, unsigned int);
typedef char *(*HASH_end)(void *, char *);
typedef char *(*HASH_file)(char *, char *);
  
/* this struct defines a message digest algorithm */
typedef struct alg_t {
	const char     *name;
	int		hash_len;
	HASH_init	hash_init;
	HASH_update	hash_update;
	HASH_end	hash_end;
	HASH_file	hash_file;
	union {
		MD5_CTX			m;
		SHA1_CTX		sha;
		RMD160_CTX		rmd;
		SHA256_CTX		sha256;
		SHA384_CTX		sha384;
		SHA512_CTX		sha512;
		tiger_context_t		tiger;
		whirlpool_context_t	whirlpool;
	} hash_ctx, hash_ctx2;
} alg_t;

/* list of supported message digest algorithms */
static alg_t algorithms[] = {
	{ "MD5",	16,
	  (HASH_init) MD5Init,		(HASH_update) MD5Update,
	  (HASH_end) MD5End,		(HASH_file) MD5File },
	{ "RMD160",	20,
	  (HASH_init) RMD160Init,	(HASH_update) RMD160Update,
	  (HASH_end) RMD160End,		(HASH_file) RMD160File },
	{ "SHA1",	20,
	  (HASH_init) SHA1Init,		(HASH_update) SHA1Update,
	  (HASH_end) SHA1End,		(HASH_file) SHA1File },
	{ "SHA256",	SHA256_DIGEST_LENGTH,
	  (HASH_init) SHA256_Init,	(HASH_update) SHA256_Update,
	  (HASH_end) SHA256_End,	(HASH_file) SHA256_File },
	{ "SHA384",	SHA384_DIGEST_LENGTH,
	  (HASH_init) SHA384_Init,	(HASH_update) SHA384_Update,
	  (HASH_end) SHA384_End,	(HASH_file) SHA384_File },
	{ "SHA512",	SHA512_DIGEST_LENGTH,
	  (HASH_init) SHA512_Init,	(HASH_update) SHA512_Update,
	  (HASH_end) SHA512_End,	(HASH_file) SHA512_File },
	{ "TIGER",	20,
	  (HASH_init) TIGERInit,	(HASH_update) TIGERUpdate,
	  (HASH_end) TIGEREnd,		(HASH_file) TIGERFile },
	{ "WHIRLPOOL",	WHIRLPOOL_DIGEST_BYTES,
	  (HASH_init) whirlpool_init,	(HASH_update) whirlpool_update,
	  (HASH_end) whirlpool_end,	(HASH_file) whirlpool_file },
	{ NULL }
};

/* find an algorithm, given a name */
static alg_t *
find_algorithm(const char *a)
{
	alg_t	*alg;

	for (alg = algorithms ; alg->name && strcasecmp(alg->name, a) != 0 ; alg++) {
	}
	return (alg->name) ? alg : NULL;
}

/* compute a digest, and print the results if successful */
static int
digest_file(char *fn, alg_t *alg)
{
	char	in[BUFSIZ * 20];
	char   *digest;
	int	cc, rc;

	digest = malloc(alg->hash_len * 2 + 1);

        if (fn == NULL) {
		(*alg->hash_init)(&alg->hash_ctx);
                while ((cc = read(STDIN_FILENO, in, sizeof(in))) > 0) {
			(*alg->hash_update)(&alg->hash_ctx, (u_char *)in,
					    (unsigned) cc);
		}
		(void) printf("%s\n", (*alg->hash_end)(&alg->hash_ctx, digest));
		rc = 1;
	} else {
		if ((*alg->hash_file)(fn, digest) == NULL) {
			rc = 0;
		} else {
			(void) printf("%s (%s) = %s\n", alg->name, fn, digest);
			rc = 1;
		}
	}

	free(digest);

	return (rc);
}

struct excl {
	LIST_ENTRY(excl) n;
	const char *p;
};

LIST_HEAD(, excl) excl;

static void
exclude(const char *p)
{
	struct excl *e;

	e = malloc(sizeof(struct excl));
	e->p = p;
	LIST_INSERT_HEAD(&excl, e, n);
}

static int
skip(const char *p)
{
	struct excl *e;

#ifdef LIST_FOREACH
	LIST_FOREACH(e, &excl, n)
#else
	for (e = excl.lh_first; e; e = e->n.le_next)
#endif
		if (strcmp(e->p, p) == 0)
			return (1);

	return (0);
}

static int
compar(const FTSENT **fa, const FTSENT **fb)
{
	return (strcmp((*fa)->fts_name, (*fb)->fts_name));
}

static int
digest_directory(char *dn, alg_t *alg)
{
	char	in[BUFSIZ * 20], dot[2];
	char	*digest;
	int	cc, rc, l, fd, cwd;
	char	*pathlist[2];
	FTS	*ftsp;
	FTSENT	*f;

	rc = 1;
	l = alg->hash_len * 2;
	digest = malloc(l + 1);
	sprintf(dot, ".");
	pathlist[0] = dot;
	pathlist[1] = NULL;

	if ((cwd = open(".", O_RDONLY)) == -1 ||
	    chdir(dn) == -1 ||
	    (ftsp = fts_open(pathlist,
			     FTS_COMFOLLOW | FTS_NOCHDIR | FTS_PHYSICAL,
			     compar)) == NULL) {
		(void) fprintf(stderr, "%s\n", dn);
		free(digest);
		return (0);
	}

	(*alg->hash_init)(&alg->hash_ctx);

	while ((f = fts_read(ftsp)) != NULL) {
		/* skip the second pass on a directory */
		if (f->fts_info == FTS_DP)
			continue;

		/* skip directories named CVS, RCS, or SCCS */
		if ((f->fts_info == FTS_NS ||
		     S_ISDIR(f->fts_statp->st_mode)) &&
		    skip(f->fts_name)) {
			fts_set(ftsp, f, FTS_SKIP);
			continue;
		}

		/* try to handle things based on stat info */
		if (f->fts_info != FTS_NS) {
				/* only mention directories */
			if (S_ISDIR(f->fts_statp->st_mode)) {
				(*alg->hash_init)(&alg->hash_ctx2);
				(*alg->hash_update)(&alg->hash_ctx2, "d ", 2);
				(*alg->hash_update)(&alg->hash_ctx2, f->fts_path, f->fts_pathlen);
				(*alg->hash_end)(&alg->hash_ctx2, digest);
				digest[l] = '\n';
				(*alg->hash_update)(&alg->hash_ctx, digest, l + 1);

				/* hash the filename and then the contents separately */
			} else if (S_ISREG(f->fts_statp->st_mode)) {
				if ((fd = open(f->fts_path, O_RDONLY)) != -1) {
					(*alg->hash_init)(&alg->hash_ctx2);
					(*alg->hash_update)(&alg->hash_ctx2, "f ", 2);
					(*alg->hash_update)(&alg->hash_ctx2, f->fts_path, f->fts_pathlen);
					(*alg->hash_end)(&alg->hash_ctx2, &digest[0]);
					digest[l] = '\n';
					(*alg->hash_update)(&alg->hash_ctx, digest, 33);

					(*alg->hash_init)(&alg->hash_ctx2);
					while ((cc = read(fd, in, sizeof(in))) > 0) {
						(*alg->hash_update)(&alg->hash_ctx2, in, cc);
					}
					close(fd);
					(*alg->hash_end)(&alg->hash_ctx2, digest);
					digest[l] = '\n';
					(*alg->hash_update)(&alg->hash_ctx, digest, l + 1);
				} else {
					(void) fprintf(stderr, "%s\n", f->fts_path);
					rc = 0;
				}

			/* hash in symlinks as well, along with the link contents */
			} else if (S_ISLNK(f->fts_statp->st_mode)) {
				if ((cc = readlink(f->fts_path, in, sizeof(in))) > 0) {
					(*alg->hash_init)(&alg->hash_ctx2);
					(*alg->hash_update)(&alg->hash_ctx2, "l ", 2);
					(*alg->hash_update)(&alg->hash_ctx2, f->fts_path, f->fts_pathlen);
					(*alg->hash_end)(&alg->hash_ctx2, digest);
					digest[l] = '\n';
					(*alg->hash_update)(&alg->hash_ctx, digest, l + 1);

					(*alg->hash_init)(&alg->hash_ctx2);
					(*alg->hash_update)(&alg->hash_ctx2, in, cc);
					(*alg->hash_end)(&alg->hash_ctx2, digest);
					digest[l] = '\n';
					(*alg->hash_update)(&alg->hash_ctx, digest, l + 1);
				} else {
					(void) fprintf(stderr, "%s\n", f->fts_path);
					rc = 0;
				}
			}
		}
	}

	fts_close(ftsp);
	fchdir(cwd);
	close(cwd);

	if (rc == 1) {
		(*alg->hash_end)(&alg->hash_ctx, digest);
		(void) printf("%s (%s) = %s\n", alg->name, dn, digest);
	}

	free(digest);
	return (rc);
}

int
main(int argc, char **argv)
{
	alg_t  *alg;
	int	rval;
	int	i;
	struct stat st;

	LIST_INIT(&excl);

#ifdef HAVE_SETLOCALE
	(void) setlocale(LC_ALL, "");
#endif
	while ((i = getopt(argc, argv, "Vx:")) != -1) {
		switch(i) {
		case 'V':
			printf("%s\n", VERSION);
			return EXIT_SUCCESS;
		case 'x':
			exclude(optarg);
			break;
		}
	}
	argc -= optind;
	argv += optind;
	
	if (argc == 0) {
		(void) fprintf(stderr, "Usage: %s algorithm [file...]\n",
		    argv[-optind]);
		return EXIT_FAILURE;
	}
	if ((alg = find_algorithm(argv[0])) == NULL) {
		(void) fprintf(stderr, "No such algorithm `%s'\n", argv[0]);
		exit(EXIT_FAILURE);
	}
	argc--;
	argv++;
	rval = EXIT_SUCCESS;
	if (argc == 0) {
		if (!digest_file(NULL, alg)) {
			(void) fprintf(stderr, "stdin\n");
			rval = EXIT_FAILURE;
		}
	} else {
		for (i = 0 ; i < argc ; i++) {
			if (stat(argv[i], &st) == -1 ||
			    (S_ISREG(st.st_mode) && !digest_file(argv[i], alg)) ||
			    (S_ISDIR(st.st_mode) && !digest_directory(argv[i], alg))) {
				(void) fprintf(stderr, "%s\n", argv[i]);
				rval = EXIT_FAILURE;
			}
		}
	}
	return rval;
}