1 /* 2 * 3 * Copyright (c) 2001 Gert Doering. All rights reserved. 4 * Copyright (c) 2003,2004,2005 Darren Tucker. All rights reserved. 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 16 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 17 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 18 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 19 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 20 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 21 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 22 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 23 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 24 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 25 * 26 */ 27 #include "includes.h" 28 #include "auth.h" 29 #include "ssh.h" 30 #include "log.h" 31 #include "xmalloc.h" 32 #include "buffer.h" 33 34 #ifdef _AIX 35 36 #include <uinfo.h> 37 #include <sys/socket.h> 38 #include "port-aix.h" 39 40 # ifdef HAVE_SETAUTHDB 41 static char old_registry[REGISTRY_SIZE] = ""; 42 # endif 43 44 /* 45 * AIX has a "usrinfo" area where logname and other stuff is stored - 46 * a few applications actually use this and die if it's not set 47 * 48 * NOTE: TTY= should be set, but since no one uses it and it's hard to 49 * acquire due to privsep code. We will just drop support. 50 */ 51 void 52 aix_usrinfo(struct passwd *pw) 53 { 54 u_int i; 55 size_t len; 56 char *cp; 57 58 len = sizeof("LOGNAME= NAME= ") + (2 * strlen(pw->pw_name)); 59 cp = xmalloc(len); 60 61 i = snprintf(cp, len, "LOGNAME=%s%cNAME=%s%c", pw->pw_name, '\0', 62 pw->pw_name, '\0'); 63 if (usrinfo(SETUINFO, cp, i) == -1) 64 fatal("Couldn't set usrinfo: %s", strerror(errno)); 65 debug3("AIX/UsrInfo: set len %d", i); 66 67 xfree(cp); 68 } 69 70 # ifdef WITH_AIXAUTHENTICATE 71 /* 72 * Remove embedded newlines in string (if any). 73 * Used before logging messages returned by AIX authentication functions 74 * so the message is logged on one line. 75 */ 76 void 77 aix_remove_embedded_newlines(char *p) 78 { 79 if (p == NULL) 80 return; 81 82 for (; *p; p++) { 83 if (*p == '\n') 84 *p = ' '; 85 } 86 /* Remove trailing whitespace */ 87 if (*--p == ' ') 88 *p = '\0'; 89 } 90 91 /* 92 * Test specifically for the case where SYSTEM == NONE and AUTH1 contains 93 * anything other than NONE or SYSTEM, which indicates that the admin has 94 * configured the account for purely AUTH1-type authentication. 95 * 96 * Since authenticate() doesn't check AUTH1, and sshd can't sanely support 97 * AUTH1 itself, in such a case authenticate() will allow access without 98 * authentation, which is almost certainly not what the admin intends. 99 * 100 * (The native tools, eg login, will process the AUTH1 list in addition to 101 * the SYSTEM list by using ckuserID(), however ckuserID() and AUTH1 methods 102 * have been deprecated since AIX 4.2.x and would be very difficult for sshd 103 * to support. 104 * 105 * Returns 0 if an unsupportable combination is found, 1 otherwise. 106 */ 107 static int 108 aix_valid_authentications(const char *user) 109 { 110 char *auth1, *sys, *p; 111 int valid = 1; 112 113 if (getuserattr((char *)user, S_AUTHSYSTEM, &sys, SEC_CHAR) != 0) { 114 logit("Can't retrieve attribute SYSTEM for %s: %.100s", 115 user, strerror(errno)); 116 return 0; 117 } 118 119 debug3("AIX SYSTEM attribute %s", sys); 120 if (strcmp(sys, "NONE") != 0) 121 return 1; /* not "NONE", so is OK */ 122 123 if (getuserattr((char *)user, S_AUTH1, &auth1, SEC_LIST) != 0) { 124 logit("Can't retrieve attribute auth1 for %s: %.100s", 125 user, strerror(errno)); 126 return 0; 127 } 128 129 p = auth1; 130 /* A SEC_LIST is concatenated strings, ending with two NULs. */ 131 while (p[0] != '\0' && p[1] != '\0') { 132 debug3("AIX auth1 attribute list member %s", p); 133 if (strcmp(p, "NONE") != 0 && strcmp(p, "SYSTEM")) { 134 logit("Account %s has unsupported auth1 value '%s'", 135 user, p); 136 valid = 0; 137 } 138 p += strlen(p) + 1; 139 } 140 141 return (valid); 142 } 143 144 /* 145 * Do authentication via AIX's authenticate routine. We loop until the 146 * reenter parameter is 0, but normally authenticate is called only once. 147 * 148 * Note: this function returns 1 on success, whereas AIX's authenticate() 149 * returns 0. 150 */ 151 int 152 sys_auth_passwd(Authctxt *ctxt, const char *password) 153 { 154 char *authmsg = NULL, *msg = NULL, *name = ctxt->pw->pw_name; 155 int authsuccess = 0, expired, reenter, result; 156 157 do { 158 result = authenticate((char *)name, (char *)password, &reenter, 159 &authmsg); 160 aix_remove_embedded_newlines(authmsg); 161 debug3("AIX/authenticate result %d, authmsg %.100s", result, 162 authmsg); 163 } while (reenter); 164 165 if (!aix_valid_authentications(name)) 166 result = -1; 167 168 if (result == 0) { 169 authsuccess = 1; 170 171 /* 172 * Record successful login. We don't have a pty yet, so just 173 * label the line as "ssh" 174 */ 175 aix_setauthdb(name); 176 177 /* 178 * Check if the user's password is expired. 179 */ 180 expired = passwdexpired(name, &msg); 181 if (msg && *msg) { 182 buffer_append(ctxt->loginmsg, msg, strlen(msg)); 183 aix_remove_embedded_newlines(msg); 184 } 185 debug3("AIX/passwdexpired returned %d msg %.100s", expired, msg); 186 187 switch (expired) { 188 case 0: /* password not expired */ 189 break; 190 case 1: /* expired, password change required */ 191 ctxt->force_pwchange = 1; 192 break; 193 default: /* user can't change(2) or other error (-1) */ 194 logit("Password can't be changed for user %s: %.100s", 195 name, msg); 196 if (msg) 197 xfree(msg); 198 authsuccess = 0; 199 } 200 201 aix_restoreauthdb(); 202 } 203 204 if (authmsg != NULL) 205 xfree(authmsg); 206 207 return authsuccess; 208 } 209 210 /* 211 * Check if specified account is permitted to log in. 212 * Returns 1 if login is allowed, 0 if not allowed. 213 */ 214 int 215 sys_auth_allowed_user(struct passwd *pw, Buffer *loginmsg) 216 { 217 char *msg = NULL; 218 int result, permitted = 0; 219 struct stat st; 220 221 /* 222 * Don't perform checks for root account (PermitRootLogin controls 223 * logins via * ssh) or if running as non-root user (since 224 * loginrestrictions will always fail due to insufficient privilege). 225 */ 226 if (pw->pw_uid == 0 || geteuid() != 0) { 227 debug3("%s: not checking", __func__); 228 return 1; 229 } 230 231 result = loginrestrictions(pw->pw_name, S_RLOGIN, NULL, &msg); 232 if (result == 0) 233 permitted = 1; 234 /* 235 * If restricted because /etc/nologin exists, the login will be denied 236 * in session.c after the nologin message is sent, so allow for now 237 * and do not append the returned message. 238 */ 239 if (result == -1 && errno == EPERM && stat(_PATH_NOLOGIN, &st) == 0) 240 permitted = 1; 241 else if (msg != NULL) 242 buffer_append(loginmsg, msg, strlen(msg)); 243 if (msg == NULL) 244 msg = xstrdup("(none)"); 245 aix_remove_embedded_newlines(msg); 246 debug3("AIX/loginrestrictions returned %d msg %.100s", result, msg); 247 248 if (!permitted) 249 logit("Login restricted for %s: %.100s", pw->pw_name, msg); 250 xfree(msg); 251 return permitted; 252 } 253 254 int 255 sys_auth_record_login(const char *user, const char *host, const char *ttynm, 256 Buffer *loginmsg) 257 { 258 char *msg = NULL; 259 int success = 0; 260 261 aix_setauthdb(user); 262 if (loginsuccess((char *)user, (char *)host, (char *)ttynm, &msg) == 0) { 263 success = 1; 264 if (msg != NULL) { 265 debug("AIX/loginsuccess: msg %s", msg); 266 buffer_append(loginmsg, msg, strlen(msg)); 267 xfree(msg); 268 } 269 } 270 aix_restoreauthdb(); 271 return (success); 272 } 273 274 # ifdef CUSTOM_FAILED_LOGIN 275 /* 276 * record_failed_login: generic "login failed" interface function 277 */ 278 void 279 record_failed_login(const char *user, const char *hostname, const char *ttyname) 280 { 281 if (geteuid() != 0) 282 return; 283 284 aix_setauthdb(user); 285 # ifdef AIX_LOGINFAILED_4ARG 286 loginfailed((char *)user, (char *)hostname, (char *)ttyname, 287 AUDIT_FAIL_AUTH); 288 # else 289 loginfailed((char *)user, (char *)hostname, (char *)ttyname); 290 # endif 291 aix_restoreauthdb(); 292 } 293 # endif /* CUSTOM_FAILED_LOGIN */ 294 295 /* 296 * If we have setauthdb, retrieve the password registry for the user's 297 * account then feed it to setauthdb. This will mean that subsequent AIX auth 298 * functions will only use the specified loadable module. If we don't have 299 * setauthdb this is a no-op. 300 */ 301 void 302 aix_setauthdb(const char *user) 303 { 304 # ifdef HAVE_SETAUTHDB 305 char *registry; 306 307 if (setuserdb(S_READ) == -1) { 308 debug3("%s: Could not open userdb to read", __func__); 309 return; 310 } 311 312 if (getuserattr((char *)user, S_REGISTRY, ®istry, SEC_CHAR) == 0) { 313 if (setauthdb(registry, old_registry) == 0) 314 debug3("AIX/setauthdb set registry '%s'", registry); 315 else 316 debug3("AIX/setauthdb set registry '%s' failed: %s", 317 registry, strerror(errno)); 318 } else 319 debug3("%s: Could not read S_REGISTRY for user: %s", __func__, 320 strerror(errno)); 321 enduserdb(); 322 # endif /* HAVE_SETAUTHDB */ 323 } 324 325 /* 326 * Restore the user's registry settings from old_registry. 327 * Note that if the first aix_setauthdb fails, setauthdb("") is still safe 328 * (it restores the system default behaviour). If we don't have setauthdb, 329 * this is a no-op. 330 */ 331 void 332 aix_restoreauthdb(void) 333 { 334 # ifdef HAVE_SETAUTHDB 335 if (setauthdb(old_registry, NULL) == 0) 336 debug3("%s: restoring old registry '%s'", __func__, 337 old_registry); 338 else 339 debug3("%s: failed to restore old registry %s", __func__, 340 old_registry); 341 # endif /* HAVE_SETAUTHDB */ 342 } 343 344 # endif /* WITH_AIXAUTHENTICATE */ 345 346 # if defined(AIX_GETNAMEINFO_HACK) && !defined(BROKEN_ADDRINFO) 347 # undef getnameinfo 348 /* 349 * For some reason, AIX's getnameinfo will refuse to resolve the all-zeros 350 * IPv6 address into its textual representation ("::"), so we wrap it 351 * with a function that will. 352 */ 353 int 354 sshaix_getnameinfo(const struct sockaddr *sa, size_t salen, char *host, 355 size_t hostlen, char *serv, size_t servlen, int flags) 356 { 357 struct sockaddr_in6 *sa6; 358 u_int32_t *a6; 359 360 if (flags & (NI_NUMERICHOST|NI_NUMERICSERV) && 361 sa->sa_family == AF_INET6) { 362 sa6 = (struct sockaddr_in6 *)sa; 363 a6 = sa6->sin6_addr.u6_addr.u6_addr32; 364 365 if (a6[0] == 0 && a6[1] == 0 && a6[2] == 0 && a6[3] == 0) { 366 strlcpy(host, "::", hostlen); 367 snprintf(serv, servlen, "%d", sa6->sin6_port); 368 return 0; 369 } 370 } 371 return getnameinfo(sa, salen, host, hostlen, serv, servlen, flags); 372 } 373 # endif /* AIX_GETNAMEINFO_HACK */ 374 375 #endif /* _AIX */ 376