Security: CVE-2023-25136 Obtained from: OpenSSH-portable commit 12da78233364 Sponsored by: The FreeBSD Foundation
216 lines
6.5 KiB
C
216 lines
6.5 KiB
C
/* $OpenBSD: compat.c,v 1.121 2023/02/02 12:10:05 djm Exp $ */
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/*
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* Copyright (c) 1999, 2000, 2001, 2002 Markus Friedl. All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
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* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
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* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
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* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
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* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
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* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
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* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*/
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#include "includes.h"
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#include <sys/types.h>
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#include <stdlib.h>
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#include <string.h>
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#include <stdarg.h>
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#include "xmalloc.h"
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#include "packet.h"
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#include "compat.h"
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#include "log.h"
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#include "match.h"
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#include "kex.h"
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/* determine bug flags from SSH protocol banner */
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void
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compat_banner(struct ssh *ssh, const char *version)
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{
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int i;
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static struct {
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char *pat;
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int bugs;
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} check[] = {
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{ "OpenSSH_2.*,"
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"OpenSSH_3.0*,"
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"OpenSSH_3.1*", SSH_BUG_EXTEOF|SSH_OLD_FORWARD_ADDR|
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SSH_BUG_SIGTYPE},
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{ "OpenSSH_3.*", SSH_OLD_FORWARD_ADDR|SSH_BUG_SIGTYPE },
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{ "Sun_SSH_1.0*", SSH_BUG_NOREKEY|SSH_BUG_EXTEOF|
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SSH_BUG_SIGTYPE},
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{ "OpenSSH_2*,"
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"OpenSSH_3*,"
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"OpenSSH_4*", SSH_BUG_SIGTYPE },
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{ "OpenSSH_5*", SSH_NEW_OPENSSH|SSH_BUG_DYNAMIC_RPORT|
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SSH_BUG_SIGTYPE},
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{ "OpenSSH_6.6.1*", SSH_NEW_OPENSSH|SSH_BUG_SIGTYPE},
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{ "OpenSSH_6.5*,"
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"OpenSSH_6.6*", SSH_NEW_OPENSSH|SSH_BUG_CURVE25519PAD|
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SSH_BUG_SIGTYPE},
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{ "OpenSSH_7.4*", SSH_NEW_OPENSSH|SSH_BUG_SIGTYPE|
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SSH_BUG_SIGTYPE74},
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{ "OpenSSH_7.0*,"
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"OpenSSH_7.1*,"
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"OpenSSH_7.2*,"
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"OpenSSH_7.3*,"
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"OpenSSH_7.5*,"
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"OpenSSH_7.6*,"
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"OpenSSH_7.7*", SSH_NEW_OPENSSH|SSH_BUG_SIGTYPE},
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{ "OpenSSH*", SSH_NEW_OPENSSH },
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{ "*MindTerm*", 0 },
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{ "3.0.*", SSH_BUG_DEBUG },
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{ "3.0 SecureCRT*", SSH_OLD_SESSIONID },
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{ "1.7 SecureFX*", SSH_OLD_SESSIONID },
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{ "1.2.18*,"
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"1.2.19*,"
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"1.2.20*,"
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"1.2.21*,"
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"1.2.22*", SSH_BUG_IGNOREMSG },
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{ "1.3.2*", /* F-Secure */
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SSH_BUG_IGNOREMSG },
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{ "Cisco-1.*", SSH_BUG_DHGEX_LARGE|
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SSH_BUG_HOSTKEYS },
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{ "*SSH Compatible Server*", /* Netscreen */
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SSH_BUG_PASSWORDPAD },
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{ "*OSU_0*,"
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"OSU_1.0*,"
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"OSU_1.1*,"
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"OSU_1.2*,"
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"OSU_1.3*,"
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"OSU_1.4*,"
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"OSU_1.5alpha1*,"
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"OSU_1.5alpha2*,"
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"OSU_1.5alpha3*", SSH_BUG_PASSWORDPAD },
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{ "*SSH_Version_Mapper*",
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SSH_BUG_SCANNER },
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{ "PuTTY_Local:*," /* dev versions < Sep 2014 */
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"PuTTY-Release-0.5*," /* 0.50-0.57, DH-GEX in >=0.52 */
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"PuTTY_Release_0.5*," /* 0.58-0.59 */
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"PuTTY_Release_0.60*,"
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"PuTTY_Release_0.61*,"
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"PuTTY_Release_0.62*,"
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"PuTTY_Release_0.63*,"
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"PuTTY_Release_0.64*",
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SSH_OLD_DHGEX },
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{ "FuTTY*", SSH_OLD_DHGEX }, /* Putty Fork */
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{ "Probe-*",
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SSH_BUG_PROBE },
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{ "TeraTerm SSH*,"
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"TTSSH/1.5.*,"
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"TTSSH/2.1*,"
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"TTSSH/2.2*,"
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"TTSSH/2.3*,"
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"TTSSH/2.4*,"
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"TTSSH/2.5*,"
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"TTSSH/2.6*,"
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"TTSSH/2.70*,"
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"TTSSH/2.71*,"
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"TTSSH/2.72*", SSH_BUG_HOSTKEYS },
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{ "WinSCP_release_4*,"
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"WinSCP_release_5.0*,"
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"WinSCP_release_5.1,"
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"WinSCP_release_5.1.*,"
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"WinSCP_release_5.5,"
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"WinSCP_release_5.5.*,"
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"WinSCP_release_5.6,"
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"WinSCP_release_5.6.*,"
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"WinSCP_release_5.7,"
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"WinSCP_release_5.7.1,"
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"WinSCP_release_5.7.2,"
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"WinSCP_release_5.7.3,"
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"WinSCP_release_5.7.4",
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SSH_OLD_DHGEX },
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{ "ConfD-*",
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SSH_BUG_UTF8TTYMODE },
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{ "Twisted_*", 0 },
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{ "Twisted*", SSH_BUG_DEBUG },
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{ NULL, 0 }
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};
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/* process table, return first match */
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ssh->compat = 0;
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for (i = 0; check[i].pat; i++) {
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if (match_pattern_list(version, check[i].pat, 0) == 1) {
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debug_f("match: %s pat %s compat 0x%08x",
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version, check[i].pat, check[i].bugs);
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ssh->compat = check[i].bugs;
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return;
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}
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}
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debug_f("no match: %s", version);
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}
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/* Always returns pointer to allocated memory, caller must free. */
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char *
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compat_cipher_proposal(struct ssh *ssh, char *cipher_prop)
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{
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if (!(ssh->compat & SSH_BUG_BIGENDIANAES))
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return xstrdup(cipher_prop);
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debug2_f("original cipher proposal: %s", cipher_prop);
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if ((cipher_prop = match_filter_denylist(cipher_prop, "aes*")) == NULL)
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fatal("match_filter_denylist failed");
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debug2_f("compat cipher proposal: %s", cipher_prop);
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if (*cipher_prop == '\0')
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fatal("No supported ciphers found");
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return cipher_prop;
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}
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/* Always returns pointer to allocated memory, caller must free. */
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char *
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compat_pkalg_proposal(struct ssh *ssh, char *pkalg_prop)
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{
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if (!(ssh->compat & SSH_BUG_RSASIGMD5))
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return xstrdup(pkalg_prop);
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debug2_f("original public key proposal: %s", pkalg_prop);
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if ((pkalg_prop = match_filter_denylist(pkalg_prop, "ssh-rsa")) == NULL)
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fatal("match_filter_denylist failed");
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debug2_f("compat public key proposal: %s", pkalg_prop);
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if (*pkalg_prop == '\0')
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fatal("No supported PK algorithms found");
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return pkalg_prop;
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}
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/* Always returns pointer to allocated memory, caller must free. */
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char *
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compat_kex_proposal(struct ssh *ssh, char *p)
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{
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char *cp = NULL, *cp2 = NULL;
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if ((ssh->compat & (SSH_BUG_CURVE25519PAD|SSH_OLD_DHGEX)) == 0)
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return xstrdup(p);
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debug2_f("original KEX proposal: %s", p);
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if ((ssh->compat & SSH_BUG_CURVE25519PAD) != 0)
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if ((cp = match_filter_denylist(p,
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"curve25519-sha256@libssh.org")) == NULL)
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fatal("match_filter_denylist failed");
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if ((ssh->compat & SSH_OLD_DHGEX) != 0) {
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if ((cp2 = match_filter_denylist(cp ? cp : p,
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"diffie-hellman-group-exchange-sha256,"
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"diffie-hellman-group-exchange-sha1")) == NULL)
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fatal("match_filter_denylist failed");
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free(cp);
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cp = cp2;
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}
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if (cp == NULL || *cp == '\0')
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fatal("No supported key exchange algorithms found");
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debug2_f("compat KEX proposal: %s", cp);
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return cp;
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}
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