Annotation of src/usr.bin/ssh/compat.c, Revision 1.82
1.82 ! djm 1: /* $OpenBSD: compat.c,v 1.81 2013/05/17 00:13:13 djm 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"
1.57 markus 33: #include "buffer.h"
1.6 markus 34: #include "packet.h"
1.10 markus 35: #include "compat.h"
1.34 markus 36: #include "log.h"
1.55 markus 37: #include "match.h"
1.1 markus 38:
1.4 markus 39: int compat13 = 0;
1.6 markus 40: int compat20 = 0;
41: int datafellows = 0;
1.4 markus 42:
1.11 markus 43: void
1.6 markus 44: enable_compat20(void)
45: {
1.80 djm 46: if (compat20)
47: return;
1.64 stevesk 48: debug("Enabling compatibility mode for protocol 2.0");
1.7 markus 49: compat20 = 1;
1.6 markus 50: }
1.11 markus 51: void
1.4 markus 52: enable_compat13(void)
53: {
1.64 stevesk 54: debug("Enabling compatibility mode for protocol 1.3");
1.4 markus 55: compat13 = 1;
1.6 markus 56: }
57: /* datafellows bug compatibility */
58: void
59: compat_datafellows(const char *version)
60: {
1.55 markus 61: int i;
1.24 markus 62: static struct {
63: char *pat;
1.13 markus 64: int bugs;
65: } check[] = {
1.55 markus 66: { "OpenSSH-2.0*,"
67: "OpenSSH-2.1*,"
68: "OpenSSH_2.1*,"
69: "OpenSSH_2.2*", SSH_OLD_SESSIONID|SSH_BUG_BANNER|
1.62 markus 70: SSH_OLD_DHGEX|SSH_BUG_NOREKEY|
1.71 djm 71: SSH_BUG_EXTEOF|SSH_OLD_FORWARD_ADDR},
1.55 markus 72: { "OpenSSH_2.3.0*", SSH_BUG_BANNER|SSH_BUG_BIGENDIANAES|
1.62 markus 73: SSH_OLD_DHGEX|SSH_BUG_NOREKEY|
1.71 djm 74: SSH_BUG_EXTEOF|SSH_OLD_FORWARD_ADDR},
1.55 markus 75: { "OpenSSH_2.3.*", SSH_BUG_BIGENDIANAES|SSH_OLD_DHGEX|
1.71 djm 76: SSH_BUG_NOREKEY|SSH_BUG_EXTEOF|
77: SSH_OLD_FORWARD_ADDR},
1.55 markus 78: { "OpenSSH_2.5.0p1*,"
79: "OpenSSH_2.5.1p1*",
1.45 markus 80: SSH_BUG_BIGENDIANAES|SSH_OLD_DHGEX|
1.71 djm 81: SSH_BUG_NOREKEY|SSH_BUG_EXTEOF|
82: SSH_OLD_FORWARD_ADDR},
1.55 markus 83: { "OpenSSH_2.5.0*,"
84: "OpenSSH_2.5.1*,"
1.62 markus 85: "OpenSSH_2.5.2*", SSH_OLD_DHGEX|SSH_BUG_NOREKEY|
1.71 djm 86: SSH_BUG_EXTEOF|SSH_OLD_FORWARD_ADDR},
87: { "OpenSSH_2.5.3*", SSH_BUG_NOREKEY|SSH_BUG_EXTEOF|
88: SSH_OLD_FORWARD_ADDR},
1.62 markus 89: { "OpenSSH_2.*,"
90: "OpenSSH_3.0*,"
1.71 djm 91: "OpenSSH_3.1*", SSH_BUG_EXTEOF|SSH_OLD_FORWARD_ADDR},
92: { "OpenSSH_3.*", SSH_OLD_FORWARD_ADDR },
1.62 markus 93: { "Sun_SSH_1.0*", SSH_BUG_NOREKEY|SSH_BUG_EXTEOF},
1.78 markus 94: { "OpenSSH_4*", 0 },
1.79 markus 95: { "OpenSSH_5*", SSH_NEW_OPENSSH|SSH_BUG_DYNAMIC_RPORT},
1.78 markus 96: { "OpenSSH*", SSH_NEW_OPENSSH },
1.55 markus 97: { "*MindTerm*", 0 },
98: { "2.1.0*", SSH_BUG_SIGBLOB|SSH_BUG_HMAC|
1.41 markus 99: SSH_OLD_SESSIONID|SSH_BUG_DEBUG|
1.66 markus 100: SSH_BUG_RSASIGMD5|SSH_BUG_HBSERVICE|
101: SSH_BUG_FIRSTKEX },
1.55 markus 102: { "2.1 *", SSH_BUG_SIGBLOB|SSH_BUG_HMAC|
1.41 markus 103: SSH_OLD_SESSIONID|SSH_BUG_DEBUG|
1.66 markus 104: SSH_BUG_RSASIGMD5|SSH_BUG_HBSERVICE|
105: SSH_BUG_FIRSTKEX },
1.56 deraadt 106: { "2.0.13*,"
107: "2.0.14*,"
108: "2.0.15*,"
109: "2.0.16*,"
110: "2.0.17*,"
111: "2.0.18*,"
1.55 markus 112: "2.0.19*", SSH_BUG_SIGBLOB|SSH_BUG_HMAC|
1.31 markus 113: SSH_OLD_SESSIONID|SSH_BUG_DEBUG|
1.37 markus 114: SSH_BUG_PKSERVICE|SSH_BUG_X11FWD|
1.47 markus 115: SSH_BUG_PKOK|SSH_BUG_RSASIGMD5|
1.53 markus 116: SSH_BUG_HBSERVICE|SSH_BUG_OPENFAILURE|
1.66 markus 117: SSH_BUG_DUMMYCHAN|SSH_BUG_FIRSTKEX },
1.56 deraadt 118: { "2.0.11*,"
1.55 markus 119: "2.0.12*", SSH_BUG_SIGBLOB|SSH_BUG_HMAC|
1.49 markus 120: SSH_OLD_SESSIONID|SSH_BUG_DEBUG|
121: SSH_BUG_PKSERVICE|SSH_BUG_X11FWD|
122: SSH_BUG_PKAUTH|SSH_BUG_PKOK|
1.53 markus 123: SSH_BUG_RSASIGMD5|SSH_BUG_OPENFAILURE|
1.66 markus 124: SSH_BUG_DUMMYCHAN|SSH_BUG_FIRSTKEX },
1.55 markus 125: { "2.0.*", SSH_BUG_SIGBLOB|SSH_BUG_HMAC|
1.31 markus 126: SSH_OLD_SESSIONID|SSH_BUG_DEBUG|
127: SSH_BUG_PKSERVICE|SSH_BUG_X11FWD|
1.41 markus 128: SSH_BUG_PKAUTH|SSH_BUG_PKOK|
1.49 markus 129: SSH_BUG_RSASIGMD5|SSH_BUG_OPENFAILURE|
1.66 markus 130: SSH_BUG_DERIVEKEY|SSH_BUG_DUMMYCHAN|
131: SSH_BUG_FIRSTKEX },
1.55 markus 132: { "2.2.0*,"
133: "2.3.0*", SSH_BUG_HMAC|SSH_BUG_DEBUG|
1.66 markus 134: SSH_BUG_RSASIGMD5|SSH_BUG_FIRSTKEX },
135: { "2.3.*", SSH_BUG_DEBUG|SSH_BUG_RSASIGMD5|
136: SSH_BUG_FIRSTKEX },
1.55 markus 137: { "2.4", SSH_OLD_SESSIONID }, /* Van Dyke */
1.77 djm 138: { "2.*", SSH_BUG_DEBUG|SSH_BUG_FIRSTKEX|
139: SSH_BUG_RFWD_ADDR },
1.55 markus 140: { "3.0.*", SSH_BUG_DEBUG },
141: { "3.0 SecureCRT*", SSH_OLD_SESSIONID },
142: { "1.7 SecureFX*", SSH_OLD_SESSIONID },
143: { "1.2.18*,"
144: "1.2.19*,"
145: "1.2.20*,"
146: "1.2.21*,"
1.69 markus 147: "1.2.22*", SSH_BUG_IGNOREMSG },
1.63 markus 148: { "1.3.2*", /* F-Secure */
1.69 markus 149: SSH_BUG_IGNOREMSG },
1.55 markus 150: { "*SSH Compatible Server*", /* Netscreen */
1.38 deraadt 151: SSH_BUG_PASSWORDPAD },
1.56 deraadt 152: { "*OSU_0*,"
1.55 markus 153: "OSU_1.0*,"
154: "OSU_1.1*,"
155: "OSU_1.2*,"
156: "OSU_1.3*,"
157: "OSU_1.4*,"
158: "OSU_1.5alpha1*,"
159: "OSU_1.5alpha2*,"
160: "OSU_1.5alpha3*", SSH_BUG_PASSWORDPAD },
161: { "*SSH_Version_Mapper*",
1.39 deraadt 162: SSH_BUG_SCANNER },
1.65 mickey 163: { "Probe-*",
164: SSH_BUG_PROBE },
1.25 markus 165: { NULL, 0 }
1.6 markus 166: };
1.55 markus 167:
1.21 markus 168: /* process table, return first match */
1.24 markus 169: for (i = 0; check[i].pat; i++) {
1.55 markus 170: if (match_pattern_list(version, check[i].pat,
171: strlen(check[i].pat), 0) == 1) {
1.13 markus 172: datafellows = check[i].bugs;
1.82 ! djm 173: debug("match: %s pat %s compat 0x%08x",
! 174: version, check[i].pat, datafellows);
1.6 markus 175: return;
176: }
177: }
1.24 markus 178: debug("no match: %s", version);
1.10 markus 179: }
180:
181: #define SEP ","
182: int
183: proto_spec(const char *spec)
184: {
1.18 provos 185: char *s, *p, *q;
1.10 markus 186: int ret = SSH_PROTO_UNKNOWN;
187:
1.14 markus 188: if (spec == NULL)
189: return ret;
1.18 provos 190: q = s = xstrdup(spec);
1.19 ho 191: for ((p = strsep(&q, SEP)); p && *p != '\0'; (p = strsep(&q, SEP))) {
1.54 deraadt 192: switch (atoi(p)) {
1.10 markus 193: case 1:
194: if (ret == SSH_PROTO_UNKNOWN)
195: ret |= SSH_PROTO_1_PREFERRED;
196: ret |= SSH_PROTO_1;
197: break;
198: case 2:
199: ret |= SSH_PROTO_2;
200: break;
201: default:
1.67 itojun 202: logit("ignoring bad proto spec: '%s'.", p);
1.10 markus 203: break;
204: }
205: }
1.81 djm 206: free(s);
1.10 markus 207: return ret;
1.40 djm 208: }
209:
1.82 ! djm 210: /*
! 211: * Filters a proposal string, excluding any algorithm matching the 'filter'
! 212: * pattern list.
! 213: */
! 214: static char *
! 215: filter_proposal(char *proposal, const char *filter)
1.40 djm 216: {
1.57 markus 217: Buffer b;
1.82 ! djm 218: char *orig_prop, *fix_prop;
1.40 djm 219: char *cp, *tmp;
220:
1.57 markus 221: buffer_init(&b);
1.82 ! djm 222: tmp = orig_prop = xstrdup(proposal);
1.54 deraadt 223: while ((cp = strsep(&tmp, ",")) != NULL) {
1.82 ! djm 224: if (match_pattern_list(cp, filter, strlen(cp), 0) != 1) {
1.57 markus 225: if (buffer_len(&b) > 0)
226: buffer_append(&b, ",", 1);
227: buffer_append(&b, cp, strlen(cp));
1.82 ! djm 228: } else
! 229: debug2("Compat: skipping algorithm \"%s\"", cp);
1.40 djm 230: }
1.57 markus 231: buffer_append(&b, "\0", 1);
1.82 ! djm 232: fix_prop = xstrdup(buffer_ptr(&b));
1.57 markus 233: buffer_free(&b);
1.81 djm 234: free(orig_prop);
1.40 djm 235:
1.82 ! djm 236: return fix_prop;
1.1 markus 237: }
1.82 ! djm 238:
! 239: char *
! 240: compat_cipher_proposal(char *cipher_prop)
! 241: {
! 242: if (!(datafellows & SSH_BUG_BIGENDIANAES))
! 243: return cipher_prop;
! 244: debug2("%s: original cipher proposal: %s", __func__, cipher_prop);
! 245: cipher_prop = filter_proposal(cipher_prop, "aes*");
! 246: debug2("%s: compat cipher proposal: %s", __func__, cipher_prop);
! 247: if (*cipher_prop == '\0')
! 248: fatal("No supported ciphers found");
! 249: return cipher_prop;
! 250: }
! 251:
! 252:
! 253: char *
! 254: compat_pkalg_proposal(char *pkalg_prop)
! 255: {
! 256: if (!(datafellows & SSH_BUG_RSASIGMD5))
! 257: return pkalg_prop;
! 258: debug2("%s: original public key proposal: %s", __func__, pkalg_prop);
! 259: pkalg_prop = filter_proposal(pkalg_prop, "ssh-rsa");
! 260: debug2("%s: compat public key proposal: %s", __func__, pkalg_prop);
! 261: if (*pkalg_prop == '\0')
! 262: fatal("No supported PK algorithms found");
! 263: return pkalg_prop;
! 264: }
! 265: