Mercurial > dropbear
view genrsa.c @ 1499:2d450c1056e3
options: Complete the transition to numeric toggles (`#if')
For the sake of review, this commit alters only the code; the affiliated
comments within the source files also need to be updated, but doing so
now would obscure the operational changes that have been made here.
* All on/off options have been switched to the numeric `#if' variant;
that is the only way to make this `default_options.h.in' thing work
in a reasonable manner.
* There is now some very minor compile-time checking of the user's
choice of options.
* NO_FAST_EXPTMOD doesn't seem to be used, so it has been removed.
* ENABLE_USER_ALGO_LIST was supposed to be renamed DROPBEAR_USER_ALGO_LIST,
and this commit completes that work.
* DROPBEAR_FUZZ seems to be a relatively new, as-yet undocumented option,
which was added by the following commit:
commit 6e0b539e9ca0b5628c6c5a3d118ad6a2e79e8039
Author: Matt Johnston <[email protected]>
Date: Tue May 23 22:29:21 2017 +0800
split out checkpubkey_line() separately
It has now been added to `sysoptions.h' and defined as `0' by default.
* The configuration option `DROPBEAR_PASSWORD_ENV' is no longer listed in
`default_options.h.in'; it is no longer meant to be set by the user, and
is instead left to be defined in `sysoptions.h' (where it was already being
defined) as merely the name of the environment variable in question:
DROPBEAR_PASSWORD
To enable or disable use of that environment variable, the user must now
toggle `DROPBEAR_USE_DROPBEAR_PASSWORD'.
* The sFTP support is now toggled by setting `DROPBEAR_SFTPSERVER', and the
path of the sFTP server program is set independently through the usual
SFTPSERVER_PATH.
author | Michael Witten <mfwitten@gmail.com> |
---|---|
date | Thu, 20 Jul 2017 19:38:26 +0000 |
parents | 750ec4ec4cbe |
children | f52919ffd3b1 |
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/* * Dropbear - a SSH2 server * * Copyright (c) 2002,2003 Matt Johnston * All rights reserved. * * Permission is hereby granted, free of charge, to any person obtaining a copy * of this software and associated documentation files (the "Software"), to deal * in the Software without restriction, including without limitation the rights * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell * copies of the Software, and to permit persons to whom the Software is * furnished to do so, subject to the following conditions: * * The above copyright notice and this permission notice shall be included in * all copies or substantial portions of the Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE * SOFTWARE. */ #include "includes.h" #include "dbutil.h" #include "bignum.h" #include "dbrandom.h" #include "rsa.h" #include "genrsa.h" #define RSA_E 65537 #if DROPBEAR_RSA static void getrsaprime(mp_int* prime, mp_int *primeminus, mp_int* rsa_e, unsigned int size_bytes); /* mostly taken from libtomcrypt's rsa key generation routine */ dropbear_rsa_key * gen_rsa_priv_key(unsigned int size) { dropbear_rsa_key * key; DEF_MP_INT(pminus); DEF_MP_INT(qminus); DEF_MP_INT(lcm); if (size < 512 || size > 4096 || (size % 8 != 0)) { dropbear_exit("Bits must satisfy 512 <= bits <= 4096, and be a" " multiple of 8"); } key = m_malloc(sizeof(*key)); m_mp_alloc_init_multi(&key->e, &key->n, &key->d, &key->p, &key->q, NULL); m_mp_init_multi(&pminus, &lcm, &qminus, NULL); if (mp_set_int(key->e, RSA_E) != MP_OKAY) { fprintf(stderr, "RSA generation failed\n"); exit(1); } while (1) { getrsaprime(key->p, &pminus, key->e, size/16); getrsaprime(key->q, &qminus, key->e, size/16); if (mp_mul(key->p, key->q, key->n) != MP_OKAY) { fprintf(stderr, "RSA generation failed\n"); exit(1); } if ((unsigned int)mp_count_bits(key->n) == size) { break; } } /* lcm(p-1, q-1) */ if (mp_lcm(&pminus, &qminus, &lcm) != MP_OKAY) { fprintf(stderr, "RSA generation failed\n"); exit(1); } /* de = 1 mod lcm(p-1,q-1) */ /* therefore d = (e^-1) mod lcm(p-1,q-1) */ if (mp_invmod(key->e, &lcm, key->d) != MP_OKAY) { fprintf(stderr, "RSA generation failed\n"); exit(1); } mp_clear_multi(&pminus, &qminus, &lcm, NULL); return key; } /* return a prime suitable for p or q */ static void getrsaprime(mp_int* prime, mp_int *primeminus, mp_int* rsa_e, unsigned int size_bytes) { unsigned char *buf; DEF_MP_INT(temp_gcd); buf = (unsigned char*)m_malloc(size_bytes); m_mp_init(&temp_gcd); do { /* generate a random odd number with MSB set, then find the the next prime above it */ genrandom(buf, size_bytes); buf[0] |= 0x80; bytes_to_mp(prime, buf, size_bytes); /* find the next integer which is prime, 8 round of miller-rabin */ if (mp_prime_next_prime(prime, 8, 0) != MP_OKAY) { fprintf(stderr, "RSA generation failed\n"); exit(1); } /* subtract one to get p-1 */ if (mp_sub_d(prime, 1, primeminus) != MP_OKAY) { fprintf(stderr, "RSA generation failed\n"); exit(1); } /* check relative primality to e */ if (mp_gcd(primeminus, rsa_e, &temp_gcd) != MP_OKAY) { fprintf(stderr, "RSA generation failed\n"); exit(1); } } while (mp_cmp_d(&temp_gcd, 1) != MP_EQ); /* while gcd(p-1, e) != 1 */ /* now we have a good value for result */ mp_clear(&temp_gcd); m_burn(buf, size_bytes); m_free(buf); } #endif /* DROPBEAR_RSA */