Mercurial > dropbear
view common-runopts.c @ 994:5c5ade336926
Prefer stronger algorithms in algorithm negotiation.
Prefer diffie-hellman-group14-sha1 (2048 bit) over
diffie-hellman-group1-sha1 (1024 bit).
Due to meet-in-the-middle attacks the effective key length of
three key 3DES is 112 bits. AES is stronger and faster then 3DES.
Prefer to delay the start of compression until after authentication
has completed. This avoids exposing compression code to attacks
from unauthenticated users.
(github pull request #9)
author | Fedor Brunner <fedor.brunner@azet.sk> |
---|---|
date | Fri, 23 Jan 2015 23:00:25 +0800 |
parents | f92eb625c48d |
children | 750ec4ec4cbe |
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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 "runopts.h" #include "signkey.h" #include "buffer.h" #include "dbutil.h" #include "auth.h" #include "algo.h" #include "dbrandom.h" runopts opts; /* GLOBAL */ /* returns success or failure, and the keytype in *type. If we want * to restrict the type, type can contain a type to return */ int readhostkey(const char * filename, sign_key * hostkey, enum signkey_type *type) { int ret = DROPBEAR_FAILURE; buffer *buf; buf = buf_new(MAX_PRIVKEY_SIZE); if (buf_readfile(buf, filename) == DROPBEAR_FAILURE) { goto out; } buf_setpos(buf, 0); addrandom(buf_getptr(buf, buf->len), buf->len); if (buf_get_priv_key(buf, hostkey, type) == DROPBEAR_FAILURE) { goto out; } ret = DROPBEAR_SUCCESS; out: buf_burn(buf); buf_free(buf); return ret; } #ifdef ENABLE_USER_ALGO_LIST void parse_ciphers_macs() { if (opts.cipher_list) { if (strcmp(opts.cipher_list, "help") == 0) { char *ciphers = algolist_string(sshciphers); dropbear_log(LOG_INFO, "Available ciphers:\n%s\n", ciphers); m_free(ciphers); dropbear_exit("."); } if (strcmp(opts.cipher_list, "none") == 0) { /* Encryption is required during authentication */ opts.cipher_list = "none,aes128-ctr"; } if (check_user_algos(opts.cipher_list, sshciphers, "cipher") == 0) { dropbear_exit("No valid ciphers specified for '-c'"); } } if (opts.mac_list) { if (strcmp(opts.mac_list, "help") == 0) { char *macs = algolist_string(sshhashes); dropbear_log(LOG_INFO, "Available MACs:\n%s\n", macs); m_free(macs); dropbear_exit("."); } if (check_user_algos(opts.mac_list, sshhashes, "MAC") == 0) { dropbear_exit("No valid MACs specified for '-m'"); } } } #endif void print_version() { fprintf(stderr, "Dropbear v%s\n", DROPBEAR_VERSION); }