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 <errno.h> 37 #include <uinfo.h> 38 #include <sys/socket.h> 39 #include "port-aix.h" 40 41 # ifdef HAVE_SETAUTHDB 42 static char old_registry[REGISTRY_SIZE] = ""; 43 # endif 44 45 /* 46 * AIX has a "usrinfo" area where logname and other stuff is stored - 47 * a few applications actually use this and die if it's not set 48 * 49 * NOTE: TTY= should be set, but since no one uses it and it's hard to 50 * acquire due to privsep code. We will just drop support. 51 */ 52 void 53 aix_usrinfo(struct passwd *pw) 54 { 55 u_int i; 56 size_t len; 57 char *cp; 58 59 len = sizeof("LOGNAME= NAME= ") + (2 * strlen(pw->pw_name)); 60 cp = xmalloc(len); 61 62 i = snprintf(cp, len, "LOGNAME=%s%cNAME=%s%c", pw->pw_name, '\0', 63 pw->pw_name, '\0'); 64 if (usrinfo(SETUINFO, cp, i) == -1) 65 fatal("Couldn't set usrinfo: %s", strerror(errno)); 66 debug3("AIX/UsrInfo: set len %d", i); 67 68 xfree(cp); 69 } 70 71 # ifdef WITH_AIXAUTHENTICATE 72 /* 73 * Remove embedded newlines in string (if any). 74 * Used before logging messages returned by AIX authentication functions 75 * so the message is logged on one line. 76 */ 77 void 78 aix_remove_embedded_newlines(char *p) 79 { 80 if (p == NULL) 81 return; 82 83 for (; *p; p++) { 84 if (*p == '\n') 85 *p = ' '; 86 } 87 /* Remove trailing whitespace */ 88 if (*--p == ' ') 89 *p = '\0'; 90 } 91 92 /* 93 * Test specifically for the case where SYSTEM == NONE and AUTH1 contains 94 * anything other than NONE or SYSTEM, which indicates that the admin has 95 * configured the account for purely AUTH1-type authentication. 96 * 97 * Since authenticate() doesn't check AUTH1, and sshd can't sanely support 98 * AUTH1 itself, in such a case authenticate() will allow access without 99 * authentation, which is almost certainly not what the admin intends. 100 * 101 * (The native tools, eg login, will process the AUTH1 list in addition to 102 * the SYSTEM list by using ckuserID(), however ckuserID() and AUTH1 methods 103 * have been deprecated since AIX 4.2.x and would be very difficult for sshd 104 * to support. 105 * 106 * Returns 0 if an unsupportable combination is found, 1 otherwise. 107 */ 108 static int 109 aix_valid_authentications(const char *user) 110 { 111 char *auth1, *sys, *p; 112 int valid = 1; 113 114 if (getuserattr((char *)user, S_AUTHSYSTEM, &sys, SEC_CHAR) != 0) { 115 logit("Can't retrieve attribute SYSTEM for %s: %.100s", 116 user, strerror(errno)); 117 return 0; 118 } 119 120 debug3("AIX SYSTEM attribute %s", sys); 121 if (strcmp(sys, "NONE") != 0) 122 return 1; /* not "NONE", so is OK */ 123 124 if (getuserattr((char *)user, S_AUTH1, &auth1, SEC_LIST) != 0) { 125 logit("Can't retrieve attribute auth1 for %s: %.100s", 126 user, strerror(errno)); 127 return 0; 128 } 129 130 p = auth1; 131 /* A SEC_LIST is concatenated strings, ending with two NULs. */ 132 while (p[0] != '\0' && p[1] != '\0') { 133 debug3("AIX auth1 attribute list member %s", p); 134 if (strcmp(p, "NONE") != 0 && strcmp(p, "SYSTEM")) { 135 logit("Account %s has unsupported auth1 value '%s'", 136 user, p); 137 valid = 0; 138 } 139 p += strlen(p) + 1; 140 } 141 142 return (valid); 143 } 144 145 /* 146 * Do authentication via AIX's authenticate routine. We loop until the 147 * reenter parameter is 0, but normally authenticate is called only once. 148 * 149 * Note: this function returns 1 on success, whereas AIX's authenticate() 150 * returns 0. 151 */ 152 int 153 sys_auth_passwd(Authctxt *ctxt, const char *password) 154 { 155 char *authmsg = NULL, *msg = NULL, *name = ctxt->pw->pw_name; 156 int authsuccess = 0, expired, reenter, result; 157 158 do { 159 result = authenticate((char *)name, (char *)password, &reenter, 160 &authmsg); 161 aix_remove_embedded_newlines(authmsg); 162 debug3("AIX/authenticate result %d, authmsg %.100s", result, 163 authmsg); 164 } while (reenter); 165 166 if (!aix_valid_authentications(name)) 167 result = -1; 168 169 if (result == 0) { 170 authsuccess = 1; 171 172 /* 173 * Record successful login. We don't have a pty yet, so just 174 * label the line as "ssh" 175 */ 176 aix_setauthdb(name); 177 178 /* 179 * Check if the user's password is expired. 180 */ 181 expired = passwdexpired(name, &msg); 182 if (msg && *msg) { 183 buffer_append(ctxt->loginmsg, msg, strlen(msg)); 184 aix_remove_embedded_newlines(msg); 185 } 186 debug3("AIX/passwdexpired returned %d msg %.100s", expired, msg); 187 188 switch (expired) { 189 case 0: /* password not expired */ 190 break; 191 case 1: /* expired, password change required */ 192 ctxt->force_pwchange = 1; 193 break; 194 default: /* user can't change(2) or other error (-1) */ 195 logit("Password can't be changed for user %s: %.100s", 196 name, msg); 197 if (msg) 198 xfree(msg); 199 authsuccess = 0; 200 } 201 202 aix_restoreauthdb(); 203 } 204 205 if (authmsg != NULL) 206 xfree(authmsg); 207 208 return authsuccess; 209 } 210 211 /* 212 * Check if specified account is permitted to log in. 213 * Returns 1 if login is allowed, 0 if not allowed. 214 */ 215 int 216 sys_auth_allowed_user(struct passwd *pw, Buffer *loginmsg) 217 { 218 char *msg = NULL; 219 int result, permitted = 0; 220 struct stat st; 221 222 /* 223 * Don't perform checks for root account (PermitRootLogin controls 224 * logins via * ssh) or if running as non-root user (since 225 * loginrestrictions will always fail due to insufficient privilege). 226 */ 227 if (pw->pw_uid == 0 || geteuid() != 0) { 228 debug3("%s: not checking", __func__); 229 return 1; 230 } 231 232 result = loginrestrictions(pw->pw_name, S_RLOGIN, NULL, &msg); 233 if (result == 0) 234 permitted = 1; 235 /* 236 * If restricted because /etc/nologin exists, the login will be denied 237 * in session.c after the nologin message is sent, so allow for now 238 * and do not append the returned message. 239 */ 240 if (result == -1 && errno == EPERM && stat(_PATH_NOLOGIN, &st) == 0) 241 permitted = 1; 242 else if (msg != NULL) 243 buffer_append(loginmsg, msg, strlen(msg)); 244 if (msg == NULL) 245 msg = xstrdup("(none)"); 246 aix_remove_embedded_newlines(msg); 247 debug3("AIX/loginrestrictions returned %d msg %.100s", result, msg); 248 249 if (!permitted) 250 logit("Login restricted for %s: %.100s", pw->pw_name, msg); 251 xfree(msg); 252 return permitted; 253 } 254 255 int 256 sys_auth_record_login(const char *user, const char *host, const char *ttynm, 257 Buffer *loginmsg) 258 { 259 char *msg = NULL; 260 int success = 0; 261 262 aix_setauthdb(user); 263 if (loginsuccess((char *)user, (char *)host, (char *)ttynm, &msg) == 0) { 264 success = 1; 265 if (msg != NULL) { 266 debug("AIX/loginsuccess: msg %s", msg); 267 buffer_append(loginmsg, msg, strlen(msg)); 268 xfree(msg); 269 } 270 } 271 aix_restoreauthdb(); 272 return (success); 273 } 274 275 # ifdef CUSTOM_FAILED_LOGIN 276 /* 277 * record_failed_login: generic "login failed" interface function 278 */ 279 void 280 record_failed_login(const char *user, const char *hostname, const char *ttyname) 281 { 282 if (geteuid() != 0) 283 return; 284 285 aix_setauthdb(user); 286 # ifdef AIX_LOGINFAILED_4ARG 287 loginfailed((char *)user, (char *)hostname, (char *)ttyname, 288 AUDIT_FAIL_AUTH); 289 # else 290 loginfailed((char *)user, (char *)hostname, (char *)ttyname); 291 # endif 292 aix_restoreauthdb(); 293 } 294 # endif /* CUSTOM_FAILED_LOGIN */ 295 296 /* 297 * If we have setauthdb, retrieve the password registry for the user's 298 * account then feed it to setauthdb. This will mean that subsequent AIX auth 299 * functions will only use the specified loadable module. If we don't have 300 * setauthdb this is a no-op. 301 */ 302 void 303 aix_setauthdb(const char *user) 304 { 305 # ifdef HAVE_SETAUTHDB 306 char *registry; 307 308 if (setuserdb(S_READ) == -1) { 309 debug3("%s: Could not open userdb to read", __func__); 310 return; 311 } 312 313 if (getuserattr((char *)user, S_REGISTRY, ®istry, SEC_CHAR) == 0) { 314 if (setauthdb(registry, old_registry) == 0) 315 debug3("AIX/setauthdb set registry '%s'", registry); 316 else 317 debug3("AIX/setauthdb set registry '%s' failed: %s", 318 registry, strerror(errno)); 319 } else 320 debug3("%s: Could not read S_REGISTRY for user: %s", __func__, 321 strerror(errno)); 322 enduserdb(); 323 # endif /* HAVE_SETAUTHDB */ 324 } 325 326 /* 327 * Restore the user's registry settings from old_registry. 328 * Note that if the first aix_setauthdb fails, setauthdb("") is still safe 329 * (it restores the system default behaviour). If we don't have setauthdb, 330 * this is a no-op. 331 */ 332 void 333 aix_restoreauthdb(void) 334 { 335 # ifdef HAVE_SETAUTHDB 336 if (setauthdb(old_registry, NULL) == 0) 337 debug3("%s: restoring old registry '%s'", __func__, 338 old_registry); 339 else 340 debug3("%s: failed to restore old registry %s", __func__, 341 old_registry); 342 # endif /* HAVE_SETAUTHDB */ 343 } 344 345 # endif /* WITH_AIXAUTHENTICATE */ 346 347 # if defined(AIX_GETNAMEINFO_HACK) && !defined(BROKEN_ADDRINFO) 348 # undef getnameinfo 349 /* 350 * For some reason, AIX's getnameinfo will refuse to resolve the all-zeros 351 * IPv6 address into its textual representation ("::"), so we wrap it 352 * with a function that will. 353 */ 354 int 355 sshaix_getnameinfo(const struct sockaddr *sa, size_t salen, char *host, 356 size_t hostlen, char *serv, size_t servlen, int flags) 357 { 358 struct sockaddr_in6 *sa6; 359 u_int32_t *a6; 360 361 if (flags & (NI_NUMERICHOST|NI_NUMERICSERV) && 362 sa->sa_family == AF_INET6) { 363 sa6 = (struct sockaddr_in6 *)sa; 364 a6 = sa6->sin6_addr.u6_addr.u6_addr32; 365 366 if (a6[0] == 0 && a6[1] == 0 && a6[2] == 0 && a6[3] == 0) { 367 strlcpy(host, "::", hostlen); 368 snprintf(serv, servlen, "%d", sa6->sin6_port); 369 return 0; 370 } 371 } 372 return getnameinfo(sa, salen, host, hostlen, serv, servlen, flags); 373 } 374 # endif /* AIX_GETNAMEINFO_HACK */ 375 376 #endif /* _AIX */ 377