From 874d77bb134a21a5cf625956b60173376a993ba8 Mon Sep 17 00:00:00 2001 From: Damien Miller Date: Sat, 14 Oct 2000 16:23:11 +1100 Subject: - (djm) Big OpenBSD sync: - markus@cvs.openbsd.org 2000/09/30 10:27:44 [log.c] allow loglevel debug - markus@cvs.openbsd.org 2000/10/03 11:59:57 [packet.c] hmac->mac - markus@cvs.openbsd.org 2000/10/03 12:03:03 [auth-krb4.c auth-passwd.c auth-rh-rsa.c auth-rhosts.c auth-rsa.c auth1.c] move fake-auth from auth1.c to individual auth methods, disables s/key in debug-msg - markus@cvs.openbsd.org 2000/10/03 12:16:48 ssh.c do not resolve canonname, i have no idea why this was added oin ossh - markus@cvs.openbsd.org 2000/10/09 15:30:44 ssh-keygen.1 ssh-keygen.c -X now reads private ssh.com DSA keys, too. - markus@cvs.openbsd.org 2000/10/09 15:32:34 auth-options.c clear options on every call. - markus@cvs.openbsd.org 2000/10/09 15:51:00 authfd.c authfd.h interop with ssh-agent2, from - markus@cvs.openbsd.org 2000/10/10 14:20:45 compat.c use rexexp for version string matching - provos@cvs.openbsd.org 2000/10/10 22:02:18 [kex.c kex.h myproposal.h ssh.h ssh2.h sshconnect2.c sshd.c dh.c dh.h] First rough implementation of the diffie-hellman group exchange. The client can ask the server for bigger groups to perform the diffie-hellman in, thus increasing the attack complexity when using ciphers with longer keys. University of Windsor provided network, T the company. - markus@cvs.openbsd.org 2000/10/11 13:59:52 [auth-rsa.c auth2.c] clear auth options unless auth sucessfull - markus@cvs.openbsd.org 2000/10/11 14:00:27 [auth-options.h] clear auth options unless auth sucessfull - markus@cvs.openbsd.org 2000/10/11 14:03:27 [scp.1 scp.c] support 'scp -o' with help from mouring@pconline.com - markus@cvs.openbsd.org 2000/10/11 14:11:35 [dh.c] Wall - markus@cvs.openbsd.org 2000/10/11 14:14:40 [auth.h auth2.c readconf.c readconf.h readpass.c servconf.c servconf.h] [ssh.h sshconnect2.c sshd_config auth2-skey.c cli.c cli.h] add support for s/key (kbd-interactive) to ssh2, based on work by mkiernan@avantgo.com and me - markus@cvs.openbsd.org 2000/10/11 14:27:24 [auth.c auth1.c auth2.c authfile.c cipher.c cipher.h kex.c kex.h] [myproposal.h packet.c readconf.c session.c ssh.c ssh.h sshconnect1.c] [sshconnect2.c sshd.c] new cipher framework - markus@cvs.openbsd.org 2000/10/11 14:45:21 [cipher.c] remove DES - markus@cvs.openbsd.org 2000/10/12 03:59:20 [cipher.c cipher.h sshconnect1.c sshconnect2.c sshd.c] enable DES in SSH-1 clients only - markus@cvs.openbsd.org 2000/10/12 08:21:13 [kex.h packet.c] remove unused - markus@cvs.openbsd.org 2000/10/13 12:34:46 [sshd.c] Kludge for F-Secure Macintosh < 1.0.2; appro@fy.chalmers.se - markus@cvs.openbsd.org 2000/10/13 12:59:15 [cipher.c cipher.h myproposal.h rijndael.c rijndael.h] rijndael/aes support - markus@cvs.openbsd.org 2000/10/13 13:10:54 [sshd.8] more info about -V - markus@cvs.openbsd.org 2000/10/13 13:12:02 [myproposal.h] prefer no compression --- dh.c | 157 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 157 insertions(+) create mode 100644 dh.c (limited to 'dh.c') diff --git a/dh.c b/dh.c new file mode 100644 index 000000000..ff84619cf --- /dev/null +++ b/dh.c @@ -0,0 +1,157 @@ +/* + * Copyright (c) 2000 Niels Provos. 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 "includes.h" +RCSID("$OpenBSD: dh.c,v 1.2 2000/10/11 20:11:35 markus Exp $"); + +#include "xmalloc.h" + +#include +#include +#include + +#include "ssh.h" +#include "buffer.h" +#include "kex.h" +#include "dh.h" + +int +parse_prime(int linenum, char *line, struct dhgroup *dhg) +{ + char *cp, *arg; + char *strsize, *gen, *prime; + + cp = line; + arg = strdelim(&cp); + /* Ignore leading whitespace */ + if (*arg == '\0') + arg = strdelim(&cp); + if (!*arg || *arg == '#') + return 0; + + /* time */ + if (cp == NULL || *arg == '\0') + goto fail; + arg = strsep(&cp, " "); /* type */ + if (cp == NULL || *arg == '\0') + goto fail; + arg = strsep(&cp, " "); /* tests */ + if (cp == NULL || *arg == '\0') + goto fail; + arg = strsep(&cp, " "); /* tries */ + if (cp == NULL || *arg == '\0') + goto fail; + strsize = strsep(&cp, " "); /* size */ + if (cp == NULL || *strsize == '\0' || + (dhg->size = atoi(strsize)) == 0) + goto fail; + gen = strsep(&cp, " "); /* gen */ + if (cp == NULL || *gen == '\0') + goto fail; + prime = strsep(&cp, " "); /* prime */ + if (cp != NULL || *prime == '\0') + goto fail; + + dhg->g = BN_new(); + if (BN_hex2bn(&dhg->g, gen) < 0) { + BN_free(dhg->g); + goto fail; + } + dhg->p = BN_new(); + if (BN_hex2bn(&dhg->p, prime) < 0) { + BN_free(dhg->g); + BN_free(dhg->p); + goto fail; + } + + return (1); + fail: + fprintf(stderr, "Bad prime description in line %d\n", linenum); + return (0); +} + +DH * +choose_dh(int minbits) +{ + FILE *f; + char line[1024]; + int best, bestcount, which; + int linenum; + struct dhgroup dhg; + + f = fopen(DH_PRIMES, "r"); + if (!f) { + perror(DH_PRIMES); + log("WARNING: %s does not exist, using old prime", DH_PRIMES); + return (dh_new_group1()); + } + + linenum = 0; + best = bestcount = 0; + while (fgets(line, sizeof(line), f)) { + linenum++; + if (!parse_prime(linenum, line, &dhg)) + continue; + BN_free(dhg.g); + BN_free(dhg.p); + + if ((dhg.size > minbits && dhg.size < best) || + (dhg.size > best && best < minbits)) { + best = dhg.size; + bestcount = 0; + } + if (dhg.size == best) + bestcount++; + } + fclose (f); + + if (bestcount == 0) { + log("WARNING: no primes in %s, using old prime", DH_PRIMES); + return (dh_new_group1()); + } + + f = fopen(DH_PRIMES, "r"); + if (!f) { + perror(DH_PRIMES); + exit(1); + } + + linenum = 0; + which = arc4random() % bestcount; + while (fgets(line, sizeof(line), f)) { + if (!parse_prime(linenum, line, &dhg)) + continue; + if (dhg.size != best) + continue; + if (linenum++ != which) { + BN_free(dhg.g); + BN_free(dhg.p); + continue; + } + break; + } + fclose(f); + + return (dh_new_group(dhg.g, dhg.p)); +} -- cgit v1.2.3