/*
* This file is part of the SSH Library
*
* Copyright (c) 2014 by Aris Adamantiadis <aris@badcode.be>
*
* The SSH Library is free software; you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as published by
* the Free Software Foundation; either version 2.1 of the License, or (at your
* option) any later version.
*
* The SSH Library is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
* or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
* License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with the SSH Library; see the file COPYING. If not, write to
* the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
* MA 02111-1307, USA.
*/
#include "config.h"
#include <stdio.h>
#include "libssh/priv.h"
#include "libssh/bignum.h"
#include "libssh/string.h"
ssh_string ssh_make_bignum_string(bignum num) {
ssh_string ptr = NULL;
int pad = 0;
unsigned int len = bignum_num_bytes(num);
unsigned int bits = bignum_num_bits(num);
if (len == 0) {
return NULL;
}
/* If the first bit is set we have a negative number */
if (!(bits % 8) && bignum_is_bit_set(num, bits - 1)) {
pad++;
}
#ifdef DEBUG_CRYPTO
fprintf(stderr, "%d bits, %d bytes, %d padding\n", bits, len, pad);
#endif /* DEBUG_CRYPTO */
ptr = ssh_string_new(len + pad);
if (ptr == NULL) {
return NULL;
}
/* We have a negative number so we need a leading zero */
if (pad) {
ptr->data[0] = 0;
}
bignum_bn2bin(num, len, ptr->data + pad);
return ptr;
}
bignum ssh_make_string_bn(ssh_string string)
{
bignum bn = NULL;
size_t len = ssh_string_len(string);
#ifdef DEBUG_CRYPTO
fprintf(stderr, "Importing a %zu bits, %zu bytes object ...\n",
len * 8, len);
#endif /* DEBUG_CRYPTO */
bignum_bin2bn(string->data, len, &bn);
return bn;
}
/* prints the bignum on stderr */
void ssh_print_bignum(const char *name, const bignum num)
{
unsigned char *hex = NULL;
if (num != NULL) {
bignum_bn2hex(num, &hex);
}
fprintf(stderr, "%s value: %s\n", name, (hex == NULL) ? "(null)" : (char *) hex);
#ifdef HAVE_LIBGCRYPT
SAFE_FREE(hex);
#elif defined HAVE_LIBCRYPTO
OPENSSL_free(hex);
#elif defined HAVE_LIBMBEDCRYPTO
SAFE_FREE(hex);
#endif
}