You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
gentoo-overlay/net-misc/openssh-blacklist/files/blacklist-encode.c

250 lines
6.4 KiB

/*
* The blacklist encoder for RSA/DSA key blacklisting based on partial
* fingerprints,
* developed under Openwall Project for Owl - http://www.openwall.com/Owl/
*
* Copyright (c) 2008 Dmitry V. Levin <ldv at cvs.openwall.com>
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*
* The blacklist encoding was designed by Solar Designer and Dmitry V. Levin.
* No intellectual property rights to the encoding scheme are claimed.
*
* This effort was supported by CivicActions - http://www.civicactions.com
*
* The file size to encode 294,903 of 48-bit fingerprints is just 1.3 MB,
* which corresponds to less than 4.5 bytes per fingerprint.
*/
#ifndef _GNU_SOURCE
# define _GNU_SOURCE
#endif
#include <string.h>
#include <stdlib.h>
#include <stdint.h>
#include <stdio.h>
#include <errno.h>
#include <error.h>
#include <limits.h>
static void *
xmalloc(size_t size)
{
void *r = malloc(size);
if (!r)
error(EXIT_FAILURE, errno, "malloc: allocating %lu bytes",
(unsigned long) size);
return r;
}
static void *
xcalloc(size_t nmemb, size_t size)
{
void *r = calloc(nmemb, size);
if (!r)
error(EXIT_FAILURE, errno, "calloc: allocating %lu*%lu bytes",
(unsigned long) nmemb, (unsigned long) size);
return r;
}
static void *
xrealloc(void *ptr, size_t nmemb, size_t elem_size)
{
if (nmemb && ULONG_MAX / nmemb < elem_size)
error(EXIT_FAILURE, 0, "realloc: nmemb*size > ULONG_MAX");
size_t size = nmemb * elem_size;
void *r = realloc(ptr, size);
if (!r)
error(EXIT_FAILURE, errno,
"realloc: allocating %lu*%lu bytes",
(unsigned long) nmemb, (unsigned long) elem_size);
return r;
}
static char *
xstrdup(const char *s)
{
size_t len = strlen(s);
char *r = xmalloc(len + 1);
memcpy(r, s, len + 1);
return r;
}
static unsigned
c2u(uint8_t c)
{
return (c >= 'a') ? (c - 'a' + 10) : (c - '0');
}
static char **records = NULL;
static unsigned records_count = 0;
static int
comparator(const void *p1, const void *p2)
{
return strcmp(*(char *const *) p1, *(char *const *) p2);
}
static void
read_stream(FILE *fp, unsigned bytes)
{
char *line = NULL;
unsigned size = 0, allocated = 0, len = bytes * 2;
int n;
while ((n = getline(&line, &size, fp)) >= 0)
{
if (n > 0 && line[n - 1] == '\n')
line[--n] = '\0';
if (n < len || strspn(line, "0123456789abcdef") < n)
continue; /* ignore short or invalid lines */
line[len] = '\0';
if (!records)
records = xcalloc(allocated = 1024, sizeof(*records));
if (records_count >= allocated)
records = xrealloc(records, allocated *= 2,
sizeof(*records));
records[records_count++] = xstrdup(line);
}
free(line);
records = xrealloc(records, records_count, sizeof(*records));
if (records_count >= (1U << 24))
error(EXIT_FAILURE, 0, "too many records: %u", records_count);
qsort(records, records_count, sizeof(*records), comparator);
}
static void
print_uint8(FILE *fp, uint8_t v)
{
fprintf(fp, "%c", v);
}
static void
print_uint16(FILE *fp, uint16_t v)
{
fprintf(fp, "%c%c", v >> 8, v & 0xff);
}
static void
print_uint24(FILE *fp, uint32_t v)
{
fprintf(fp, "%c%c%c", (v >> 16) & 0xff, (v >> 8) & 0xff, v & 0xff);
}
int
main(int ac, const char **av)
{
unsigned count, i, record_bytes, first_index = 0, prev_index = 0;
int min_offset, max_offset;
int *offsets;
if (ac < 2)
error(EXIT_FAILURE, 0, "insufficient arguments");
if (ac > 2)
error(EXIT_FAILURE, 0, "too many arguments");
record_bytes = atoi(av[1]);
if (record_bytes < 6 || record_bytes > 16)
error(EXIT_FAILURE, 0, "fingerprint size out of bounds");
read_stream(stdin, record_bytes);
/* initialize global records offset table */
offsets = xcalloc(65536, sizeof(*offsets));
for (count = 0; count < records_count; ++count, prev_index = i)
{
const char *r = records[count];
i = (((((c2u(r[0]) << 4) + c2u(r[1])) << 4) +
c2u(r[2])) << 4) + c2u(r[3]);
if (count == 0)
first_index = i;
else if (i == prev_index)
continue;
offsets[i] = count;
}
/* set offsets for indices without records */
if (offsets[65536 - 1] == 0)
offsets[65536 - 1] = records_count;
for (i = 65536 - 2; i > first_index; --i)
if (offsets[i] == 0)
offsets[i] = offsets[i + 1];
/* make global records offset table relative to
expected position assuming uniform distribution. */
for (i = 0, min_offset = 0, max_offset = 0; i < 65536; ++i)
{
offsets[i] -= (i * (unsigned long long) records_count) >> 16;
if (offsets[i] < min_offset)
min_offset = offsets[i];
if (offsets[i] > max_offset)
max_offset = offsets[i];
}
min_offset = -min_offset;
if (min_offset < 0)
error(EXIT_FAILURE, 0,
"invalid offset shift: %d", min_offset);
for (i = 0; i < 65536; ++i)
{
offsets[i] += min_offset;
if (offsets[i] < 0 || offsets[i] >= 65536)
error(EXIT_FAILURE, 0,
"offset overflow for index %#x: %d",
i, offsets[i]);
}
max_offset += min_offset;
/* Header, 16 bytes */
/* format version identifier */
printf("SSH-FP00");
/* index size, in bits */
print_uint8(stdout, 16);
/* offset size, in bits */
print_uint8(stdout, 16);
/* record size, in bits */
print_uint8(stdout, record_bytes * 8);
/* records count */
print_uint24(stdout, records_count);
/* offset shift */
print_uint16(stdout, min_offset);
fprintf(stderr, "records=%u, offset shift=%d, max offset=%d\n",
records_count, min_offset, max_offset);
/* Index, 65536 * 2 bytes */
for (i = 0; i < 65536; ++i)
print_uint16(stdout, offsets[i]);
/* Fingerprints, records_count * (record_bytes-2) bytes */
for (count = 0; count < records_count; ++count)
{
const char *r = records[count] + 4;
for (i = 0; i < record_bytes - 2; ++i)
print_uint8(stdout,
c2u(r[i * 2]) * 16 + c2u(r[i * 2 + 1]));
}
if (fclose(stdout))
error(EXIT_FAILURE, errno, "stdout");
return 0;
}