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/*-
* Copyright (c) 2012 Alistair Crooks <agc@NetBSD.org>
* 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.
*
* 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.
*/
#include "config.h"
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/mman.h>
#include <inttypes.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include "digest.h"
#include "pgpsum.h"
#ifndef USE_ARG
#define USE_ARG(x) /*LINTED*/(void)&(x)
#endif
/* add the ascii armor line endings (except for last line) */
static size_t
don_armor(digest_t *hash, uint8_t *in, size_t insize, int doarmor)
{
uint8_t *from;
uint8_t *newp;
uint8_t *p;
uint8_t dos_line_end[2];
dos_line_end[0] = '\r';
dos_line_end[1] = '\n';
for (from = in ; (p = memchr(from, '\n', insize - (size_t)(from - in))) != NULL ; from = p + 1) {
for (newp = p ; doarmor == 'w' && newp > from ; --newp) {
if (*(newp - 1) != ' ' && *(newp - 1) != '\t') {
break;
}
}
digest_update(hash, from, (size_t)(newp - from));
digest_update(hash, dos_line_end, sizeof(dos_line_end));
}
digest_update(hash, from, insize - (size_t)(from - in));
return 1;
}
#ifdef NETPGPV_DEBUG
/* just for giggles, write what we're about to checksum */
static int
writefile(uint8_t *mem, size_t insize)
{
size_t cc;
size_t wc;
char template[256];
int fd;
snprintf(template, sizeof(template), "netpgpvmd.XXXXXX");
if ((fd = mkstemp(template)) < 0) {
fprintf(stderr, "can't mkstemp %s\n", template);
return 0;
}
for (cc = 0 ; cc < insize ; cc += wc) {
if ((wc = write(fd, &mem[cc], insize - cc)) <= 0) {
fprintf(stderr, "short write\n");
break;
}
}
close(fd);
return 1;
}
#endif
/* return non-zero if this is actually an armored piece already */
static int
already_armored(uint8_t *in, size_t insize)
{
uint8_t *from;
uint8_t *p;
for (from = in ; (p = memchr(from, '\n', insize - (size_t)(from - in))) != NULL ; from = p + 1) {
if (*(p - 1) != '\r') {
return 0;
}
}
return 1;
}
/* calculate the checksum for the data we have */
static int
calcsum(uint8_t *out, size_t size, uint8_t *mem, size_t cc, const uint8_t *hashed, size_t hashsize, int doarmor)
{
digest_t hash;
uint32_t len32;
uint16_t len16;
uint8_t hashalg;
uint8_t trailer[6];
USE_ARG(size);
/* hashed data is non-null (previously checked) */
hashalg = hashed[3];
memcpy(&len16, &hashed[4], sizeof(len16));
len32 = ntohs(len16) + 6;
len32 = htonl(len32);
trailer[0] = 0x04;
trailer[1] = 0xff;
memcpy(&trailer[2], &len32, sizeof(len32));
#ifdef NETPGPV_DEBUG
writefile(mem, cc);
#endif
digest_init(&hash, (const unsigned)hashalg);
if (strchr("tw", doarmor) != NULL && !already_armored(mem, cc)) {
/* this took me ages to find - something causes gpg to truncate its input */
don_armor(&hash, mem, cc - 1, doarmor);
} else {
digest_update(&hash, mem, cc);
}
if (hashed) {
digest_update(&hash, hashed, hashsize);
}
digest_update(&hash, trailer, sizeof(trailer));
return digest_final(out, &hash);
}
/* open the file, mmap it, and then get the checksum on that */
int
pgpv_digest_file(uint8_t *data, size_t size, const char *name, const uint8_t *hashed, size_t hashsize, int doarmor)
{
struct stat st;
uint8_t *mem;
size_t cc;
FILE *fp;
int ret;
if (hashed == NULL || data == NULL || name == NULL) {
fprintf(stderr, "no hashed data provided\n");
return 0;
}
ret = 0;
mem = NULL;
cc = 0;
if ((fp = fopen(name, "r")) == NULL) {
fprintf(stderr, "%s - not found", name);
return 0;
}
if (fstat(fileno(fp), &st) < 0) {
fprintf(stderr, "%s - can't stat", name);
goto done;
}
cc = (size_t)(st.st_size);
if ((mem = mmap(NULL, cc, PROT_READ, MAP_SHARED, fileno(fp), 0)) == MAP_FAILED) {
fprintf(stderr, "%s - can't mmap", name);
goto done;
}
ret = calcsum(data, size, mem, cc, hashed, hashsize, doarmor);
done:
if (data) {
munmap(mem, cc);
}
fclose(fp);
return ret;
}
/* calculate the digest over memory too */
int
pgpv_digest_memory(uint8_t *data, size_t size, void *mem, size_t cc, const uint8_t *hashed, size_t hashsize, int doarmor)
{
if (hashed == NULL || data == NULL || mem == NULL) {
fprintf(stderr, "no hashed data provided\n");
return 0;
}
return calcsum(data, size, mem, cc, hashed, hashsize, doarmor);
}
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