Annotation of src/usr.bin/ssh/compat.c, Revision 1.126
1.126 ! dtucker 1: /* $OpenBSD: compat.c,v 1.125 2023/02/17 04:22:50 dtucker Exp $ */
1.5 markus 2: /*
1.61 markus 3: * Copyright (c) 1999, 2000, 2001, 2002 Markus Friedl. All rights reserved.
1.5 markus 4: *
5: * Redistribution and use in source and binary forms, with or without
6: * modification, are permitted provided that the following conditions
7: * are met:
8: * 1. Redistributions of source code must retain the above copyright
9: * notice, this list of conditions and the following disclaimer.
10: * 2. Redistributions in binary form must reproduce the above copyright
11: * notice, this list of conditions and the following disclaimer in the
12: * documentation and/or other materials provided with the distribution.
13: *
14: * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
15: * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
16: * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
17: * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
18: * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
19: * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
20: * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
21: * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
22: * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
23: * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
24: */
25:
1.76 deraadt 26: #include <sys/types.h>
1.74 stevesk 27:
1.75 stevesk 28: #include <stdlib.h>
1.74 stevesk 29: #include <string.h>
1.76 deraadt 30: #include <stdarg.h>
1.2 markus 31:
1.76 deraadt 32: #include "xmalloc.h"
1.6 markus 33: #include "packet.h"
1.10 markus 34: #include "compat.h"
1.34 markus 35: #include "log.h"
1.55 markus 36: #include "match.h"
1.1 markus 37:
1.117 djm 38: /* determine bug flags from SSH protocol banner */
39: void
40: compat_banner(struct ssh *ssh, const char *version)
1.6 markus 41: {
1.55 markus 42: int i;
1.24 markus 43: static struct {
44: char *pat;
1.13 markus 45: int bugs;
46: } check[] = {
1.62 markus 47: { "OpenSSH_2.*,"
48: "OpenSSH_3.0*,"
1.108 djm 49: "OpenSSH_3.1*", SSH_BUG_EXTEOF|SSH_OLD_FORWARD_ADDR|
50: SSH_BUG_SIGTYPE},
51: { "OpenSSH_3.*", SSH_OLD_FORWARD_ADDR|SSH_BUG_SIGTYPE },
52: { "Sun_SSH_1.0*", SSH_BUG_NOREKEY|SSH_BUG_EXTEOF|
53: SSH_BUG_SIGTYPE},
1.105 djm 54: { "OpenSSH_2*,"
55: "OpenSSH_3*,"
1.108 djm 56: "OpenSSH_4*", SSH_BUG_SIGTYPE },
57: { "OpenSSH_5*", SSH_NEW_OPENSSH|SSH_BUG_DYNAMIC_RPORT|
58: SSH_BUG_SIGTYPE},
59: { "OpenSSH_6.6.1*", SSH_NEW_OPENSSH|SSH_BUG_SIGTYPE},
1.83 djm 60: { "OpenSSH_6.5*,"
1.108 djm 61: "OpenSSH_6.6*", SSH_NEW_OPENSSH|SSH_BUG_CURVE25519PAD|
62: SSH_BUG_SIGTYPE},
1.118 djm 63: { "OpenSSH_7.4*", SSH_NEW_OPENSSH|SSH_BUG_SIGTYPE|
64: SSH_BUG_SIGTYPE74},
1.108 djm 65: { "OpenSSH_7.0*,"
66: "OpenSSH_7.1*,"
67: "OpenSSH_7.2*,"
68: "OpenSSH_7.3*,"
69: "OpenSSH_7.5*,"
1.109 djm 70: "OpenSSH_7.6*,"
71: "OpenSSH_7.7*", SSH_NEW_OPENSSH|SSH_BUG_SIGTYPE},
1.78 markus 72: { "OpenSSH*", SSH_NEW_OPENSSH },
1.55 markus 73: { "*MindTerm*", 0 },
74: { "3.0.*", SSH_BUG_DEBUG },
75: { "3.0 SecureCRT*", SSH_OLD_SESSIONID },
76: { "1.7 SecureFX*", SSH_OLD_SESSIONID },
1.96 djm 77: { "Cisco-1.*", SSH_BUG_DHGEX_LARGE|
78: SSH_BUG_HOSTKEYS },
1.55 markus 79: { "*SSH_Version_Mapper*",
1.39 deraadt 80: SSH_BUG_SCANNER },
1.95 dtucker 81: { "PuTTY_Local:*," /* dev versions < Sep 2014 */
82: "PuTTY-Release-0.5*," /* 0.50-0.57, DH-GEX in >=0.52 */
1.93 dtucker 83: "PuTTY_Release_0.5*," /* 0.58-0.59 */
84: "PuTTY_Release_0.60*,"
85: "PuTTY_Release_0.61*,"
86: "PuTTY_Release_0.62*,"
87: "PuTTY_Release_0.63*,"
88: "PuTTY_Release_0.64*",
89: SSH_OLD_DHGEX },
1.97 djm 90: { "FuTTY*", SSH_OLD_DHGEX }, /* Putty Fork */
1.65 mickey 91: { "Probe-*",
92: SSH_BUG_PROBE },
1.89 dtucker 93: { "TeraTerm SSH*,"
94: "TTSSH/1.5.*,"
95: "TTSSH/2.1*,"
96: "TTSSH/2.2*,"
97: "TTSSH/2.3*,"
98: "TTSSH/2.4*,"
99: "TTSSH/2.5*,"
100: "TTSSH/2.6*,"
101: "TTSSH/2.70*,"
102: "TTSSH/2.71*,"
103: "TTSSH/2.72*", SSH_BUG_HOSTKEYS },
1.97 djm 104: { "WinSCP_release_4*,"
105: "WinSCP_release_5.0*,"
1.104 dtucker 106: "WinSCP_release_5.1,"
107: "WinSCP_release_5.1.*,"
108: "WinSCP_release_5.5,"
109: "WinSCP_release_5.5.*,"
110: "WinSCP_release_5.6,"
111: "WinSCP_release_5.6.*,"
1.97 djm 112: "WinSCP_release_5.7,"
113: "WinSCP_release_5.7.1,"
114: "WinSCP_release_5.7.2,"
115: "WinSCP_release_5.7.3,"
116: "WinSCP_release_5.7.4",
117: SSH_OLD_DHGEX },
1.106 dtucker 118: { "ConfD-*",
119: SSH_BUG_UTF8TTYMODE },
1.107 djm 120: { "Twisted_*", 0 },
121: { "Twisted*", SSH_BUG_DEBUG },
1.25 markus 122: { NULL, 0 }
1.6 markus 123: };
1.55 markus 124:
1.21 markus 125: /* process table, return first match */
1.117 djm 126: ssh->compat = 0;
1.24 markus 127: for (i = 0; check[i].pat; i++) {
1.91 djm 128: if (match_pattern_list(version, check[i].pat, 0) == 1) {
1.117 djm 129: debug_f("match: %s pat %s compat 0x%08x",
1.87 markus 130: version, check[i].pat, check[i].bugs);
1.117 djm 131: ssh->compat = check[i].bugs;
132: return;
1.6 markus 133: }
134: }
1.117 djm 135: debug_f("no match: %s", version);
1.40 djm 136: }
137:
1.120 dtucker 138: /* Always returns pointer to allocated memory, caller must free. */
1.82 djm 139: char *
1.126 ! dtucker 140: compat_kex_proposal(struct ssh *ssh, const char *p)
1.83 djm 141: {
1.121 djm 142: char *cp = NULL, *cp2 = NULL;
1.120 dtucker 143:
1.117 djm 144: if ((ssh->compat & (SSH_BUG_CURVE25519PAD|SSH_OLD_DHGEX)) == 0)
1.120 dtucker 145: return xstrdup(p);
1.116 djm 146: debug2_f("original KEX proposal: %s", p);
1.117 djm 147: if ((ssh->compat & SSH_BUG_CURVE25519PAD) != 0)
1.121 djm 148: if ((cp = match_filter_denylist(p,
1.100 djm 149: "curve25519-sha256@libssh.org")) == NULL)
1.115 djm 150: fatal("match_filter_denylist failed");
1.117 djm 151: if ((ssh->compat & SSH_OLD_DHGEX) != 0) {
1.121 djm 152: if ((cp2 = match_filter_denylist(cp ? cp : p,
1.100 djm 153: "diffie-hellman-group-exchange-sha256,"
154: "diffie-hellman-group-exchange-sha1")) == NULL)
1.115 djm 155: fatal("match_filter_denylist failed");
1.120 dtucker 156: free(cp);
1.121 djm 157: cp = cp2;
1.90 djm 158: }
1.121 djm 159: if (cp == NULL || *cp == '\0')
1.83 djm 160: fatal("No supported key exchange algorithms found");
1.121 djm 161: debug2_f("compat KEX proposal: %s", cp);
162: return cp;
1.82 djm 163: }
164: