OpenBSD-4.6/usr.bin/gzsig/sign.c
/* $OpenBSD: sign.c,v 1.9 2007/10/12 19:52:06 jasper Exp $ */
/*
* sign.c
*
* Copyright (c) 2001 Dug Song <dugsong@arbor.net>
* Copyright (c) 2001 Arbor Networks, Inc.
*
* 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. The names of the copyright holders may not be used to endorse or
* promote products derived from this software without specific
* prior written permission.
*
* THIS SOFTWARE IS PROVIDED ``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.
*
* $Vendor: sign.c,v 1.2 2005/04/01 16:47:31 dugsong Exp $
*/
#include <sys/param.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <openssl/ssl.h>
#include <openssl/evp.h>
#include <openssl/sha.h>
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <err.h>
#include "extern.h"
#include "gzip.h"
#include "key.h"
#include "util.h"
static char *passphrase_file = NULL;
static int
embed_signature(struct key *key, FILE *fin, FILE *fout)
{
struct gzip_header gh;
struct gzip_xfield *gx;
struct gzsig_data *gd;
u_char *sig, digest[20], buf[8192];
SHA_CTX ctx;
int i, siglen;
long offset;
/* Read gzip header. */
if (fread((u_char *)&gh, 1, sizeof(gh), fin) != sizeof(gh)) {
fprintf(stderr, "Error reading gzip header: %s\n",
strerror(errno));
return (-1);
}
/* Verify gzip header. */
if (memcmp(gh.magic, GZIP_MAGIC, sizeof(gh.magic)) != 0) {
fprintf(stderr, "Invalid gzip file\n");
return (-1);
}
if (gh.flags & GZIP_FCONT) {
fprintf(stderr, "Multi-part gzip files not supported\n");
return (-1);
}
/* Skip over any existing signature. */
if (gh.flags & GZIP_FEXTRA) {
gx = (struct gzip_xfield *)buf;
gd = (struct gzsig_data *)(gx + 1);
if (fread((u_char *)gx, 1, sizeof(*gx), fin) != sizeof(*gx)) {
fprintf(stderr, "Error reading extra field: %s\n",
strerror(errno));
return (-1);
}
if (memcmp(gx->subfield.id, GZSIG_ID, 2) != 0) {
fprintf(stderr, "Unknown extra field\n");
return (-1);
}
gx->subfield.len = letoh16(gx->subfield.len);
if (gx->subfield.len < sizeof(*gd) ||
gx->subfield.len > sizeof(buf) - sizeof(*gx)) {
fprintf(stderr, "Invalid signature length\n");
return (-1);
}
if (fread((u_char *)gd, 1, gx->subfield.len, fin) !=
gx->subfield.len) {
fprintf(stderr, "Error reading signature: %s\n",
strerror(errno));
return (-1);
}
fprintf(stderr, "Overwriting existing signature\n");
}
/* Skip over any options. */
offset = ftell(fin);
if (gh.flags & GZIP_FNAME) {
while (getc(fin) != '\0')
;
}
if (gh.flags & GZIP_FCOMMENT) {
while (getc(fin) != '\0')
;
}
if (gh.flags & GZIP_FENCRYPT) {
if (fread(buf, 1, GZIP_FENCRYPT_LEN, fin) != GZIP_FENCRYPT_LEN)
return (-1);
}
/* Compute checksum over compressed data and trailer. */
SHA1_Init(&ctx);
while ((i = fread(buf, 1, sizeof(buf), fin)) > 0) {
SHA1_Update(&ctx, buf, i);
}
SHA1_Final(digest, &ctx);
/* Generate signature. */
gx = (struct gzip_xfield *)buf;
gd = (struct gzsig_data *)(gx + 1);
sig = (u_char *)(gd + 1);
siglen = key_sign(key, digest, sizeof(digest), sig,
sizeof(buf) - (sig - buf));
if (siglen < 0) {
fprintf(stderr, "Error signing checksum\n");
return (-1);
}
i = sizeof(*gd) + siglen;
gx->subfield.len = htole16(i);
gx->len = htole16(sizeof(gx->subfield) + i);
memcpy(gx->subfield.id, GZSIG_ID, sizeof(gx->subfield.id));
gd->version = GZSIG_VERSION;
/* Write out gzip header. */
gh.flags |= GZIP_FEXTRA;
if (fwrite((u_char *)&gh, 1, sizeof(gh), fout) != sizeof(gh)) {
fprintf(stderr, "Error writing output: %s\n", strerror(errno));
return (-1);
}
/* Write out signature. */
if (fwrite(buf, 1, sizeof(*gx) + i, fout) != sizeof(*gx) + i) {
fprintf(stderr, "Error writing output: %s\n", strerror(errno));
return (-1);
}
/* Write out options, compressed data, and trailer. */
if (fseek(fin, offset, SEEK_SET) < 0) {
fprintf(stderr, "Error writing output: %s\n", strerror(errno));
return (-1);
}
while ((i = fread(buf, 1, sizeof(buf), fin)) > 0) {
if (fwrite(buf, 1, i, fout) != i) {
fprintf(stderr, "Error writing output: %s\n",
strerror(errno));
return (-1);
}
}
if (ferror(fin)) {
fprintf(stderr, "Error reading input: %s\n", strerror(errno));
return (-1);
}
return (0);
}
void
sign_usage(void)
{
fprintf(stderr, "Usage: %s sign [-q] [-f secret_file] privkey [file ...]\n",
__progname);
}
int
sign_passwd_cb(char *buf, int size, int rwflag, void *u)
{
char *p;
FILE *f;
if (passphrase_file != NULL) {
if ((f = fopen(passphrase_file, "r")) == NULL)
err(1, "fopen(%.64s)", passphrase_file);
if (fgets(buf, size, f) == NULL)
err(1, "fgets(%.64s)", passphrase_file);
fclose(f);
buf[strcspn(buf, "\n")] = '\0';
} else {
p = getpass("Enter passphrase: ");
if (strlcpy(buf, p, size) >= size)
errx(1, "Passphrase too long");
memset(p, 0, strlen(p));
}
return (strlen(buf));
}
void
sign(int argc, char *argv[])
{
struct key *key;
char *gzipfile, tmppath[MAXPATHLEN];
FILE *fin, *fout;
int i, fd, error, qflag;
qflag = 0;
while ((i = getopt(argc, argv, "qvf:")) != -1) {
switch (i) {
case 'q':
qflag = 1;
break;
case 'v':
qflag = 0;
break;
case 'f':
passphrase_file = optarg;
break;
default:
sign_usage();
exit(1);
}
}
argc -= optind;
argv += optind;
if (argc < 1) {
sign_usage();
exit(1);
}
OpenSSL_add_all_algorithms();
if ((key = key_new()) == NULL)
fatal(1, "Couldn't initialize private key");
if (key_load_private(key, argv[0]) < 0)
fatal(1, "Couldn't load private key");
if (argc == 1 || *argv[1] == '-') {
argc = 0;
if (embed_signature(key, stdin, stdout) == 0) {
if (!qflag)
fprintf(stderr, "Signed input\n");
} else
fatal(1, "Couldn't sign input");
}
for (i = 1; i < argc; i++) {
gzipfile = argv[i];
if ((fin = fopen(gzipfile, "r+")) == NULL) {
fprintf(stderr, "Error opening %s: %s\n",
gzipfile, strerror(errno));
continue;
}
snprintf(tmppath, sizeof(tmppath), "%s.XXXXXX", gzipfile);
if ((fd = mkstemp(tmppath)) < 0) {
fprintf(stderr, "Error creating %s: %s\n",
tmppath, strerror(errno));
fclose(fin);
continue;
}
if ((fout = fdopen(fd, "w")) == NULL) {
fprintf(stderr, "Error opening %s: %s\n",
tmppath, strerror(errno));
fclose(fin);
close(fd);
continue;
}
if (copy_permissions(gzipfile, tmppath) < 0) {
fprintf(stderr, "Error initializing %s: %s\n",
tmppath, strerror(errno));
fclose(fin);
fclose(fout);
continue;
}
error = embed_signature(key, fin, fout);
fclose(fin);
fclose(fout);
if (!error) {
if (rename(tmppath, gzipfile) < 0) {
unlink(tmppath);
fatal(1, "Couldn't sign %s", gzipfile);
}
if (!qflag)
fprintf(stderr, "Signed %s\n", gzipfile);
} else {
unlink(tmppath);
fatal(1, "Couldn't sign %s", gzipfile);
}
}
key_free(key);
}