port-aix.c revision 146998
1/* 2 * 3 * Copyright (c) 2001 Gert Doering. All rights reserved. 4 * Copyright (c) 2003,2004 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 41static 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 52 53void 54aix_usrinfo(struct passwd *pw) 55{ 56 u_int i; 57 size_t len; 58 char *cp; 59 60 len = sizeof("LOGNAME= NAME= ") + (2 * strlen(pw->pw_name)); 61 cp = xmalloc(len); 62 63 i = snprintf(cp, len, "LOGNAME=%s%cNAME=%s%c", pw->pw_name, '\0', 64 pw->pw_name, '\0'); 65 if (usrinfo(SETUINFO, cp, i) == -1) 66 fatal("Couldn't set usrinfo: %s", strerror(errno)); 67 debug3("AIX/UsrInfo: set len %d", i); 68 69 xfree(cp); 70} 71 72# ifdef WITH_AIXAUTHENTICATE 73/* 74 * Remove embedded newlines in string (if any). 75 * Used before logging messages returned by AIX authentication functions 76 * so the message is logged on one line. 77 */ 78void 79aix_remove_embedded_newlines(char *p) 80{ 81 if (p == NULL) 82 return; 83 84 for (; *p; p++) { 85 if (*p == '\n') 86 *p = ' '; 87 } 88 /* Remove trailing whitespace */ 89 if (*--p == ' ') 90 *p = '\0'; 91} 92 93/* 94 * Test specifically for the case where SYSTEM == NONE and AUTH1 contains 95 * anything other than NONE or SYSTEM, which indicates that the admin has 96 * configured the account for purely AUTH1-type authentication. 97 * 98 * Since authenticate() doesn't check AUTH1, and sshd can't sanely support 99 * AUTH1 itself, in such a case authenticate() will allow access without 100 * authentation, which is almost certainly not what the admin intends. 101 * 102 * (The native tools, eg login, will process the AUTH1 list in addition to 103 * the SYSTEM list by using ckuserID(), however ckuserID() and AUTH1 methods 104 * have been deprecated since AIX 4.2.x and would be very difficult for sshd 105 * to support. 106 * 107 * Returns 0 if an unsupportable combination is found, 1 otherwise. 108 */ 109static int 110aix_valid_authentications(const char *user) 111{ 112 char *auth1, *sys, *p; 113 int valid = 1; 114 115 if (getuserattr((char *)user, S_AUTHSYSTEM, &sys, SEC_CHAR) != 0) { 116 logit("Can't retrieve attribute SYSTEM for %s: %.100s", 117 user, strerror(errno)); 118 return 0; 119 } 120 121 debug3("AIX SYSTEM attribute %s", sys); 122 if (strcmp(sys, "NONE") != 0) 123 return 1; /* not "NONE", so is OK */ 124 125 if (getuserattr((char *)user, S_AUTH1, &auth1, SEC_LIST) != 0) { 126 logit("Can't retrieve attribute auth1 for %s: %.100s", 127 user, strerror(errno)); 128 return 0; 129 } 130 131 p = auth1; 132 /* A SEC_LIST is concatenated strings, ending with two NULs. */ 133 while (p[0] != '\0' && p[1] != '\0') { 134 debug3("AIX auth1 attribute list member %s", p); 135 if (strcmp(p, "NONE") != 0 && strcmp(p, "SYSTEM")) { 136 logit("Account %s has unsupported auth1 value '%s'", 137 user, p); 138 valid = 0; 139 } 140 p += strlen(p) + 1; 141 } 142 143 return (valid); 144} 145 146/* 147 * Do authentication via AIX's authenticate routine. We loop until the 148 * reenter parameter is 0, but normally authenticate is called only once. 149 * 150 * Note: this function returns 1 on success, whereas AIX's authenticate() 151 * returns 0. 152 */ 153int 154sys_auth_passwd(Authctxt *ctxt, const char *password, Buffer *loginmsg) 155{ 156 char *authmsg = NULL, *msg, *name = ctxt->pw->pw_name; 157 int authsuccess = 0, expired, reenter, result; 158 159 do { 160 result = authenticate((char *)name, (char *)password, &reenter, 161 &authmsg); 162 aix_remove_embedded_newlines(authmsg); 163 debug3("AIX/authenticate result %d, msg %.100s", result, 164 authmsg); 165 } while (reenter); 166 167 if (!aix_valid_authentications(name)) 168 result = -1; 169 170 if (result == 0) { 171 authsuccess = 1; 172 173 /* 174 * Record successful login. We don't have a pty yet, so just 175 * label the line as "ssh" 176 */ 177 aix_setauthdb(name); 178 179 /* 180 * Check if the user's password is expired. 181 */ 182 expired = passwdexpired(name, &msg); 183 if (msg && *msg) { 184 buffer_append(loginmsg, msg, strlen(msg)); 185 aix_remove_embedded_newlines(msg); 186 } 187 debug3("AIX/passwdexpired returned %d msg %.100s", expired, msg); 188 189 switch (expired) { 190 case 0: /* password not expired */ 191 break; 192 case 1: /* expired, password change required */ 193 ctxt->force_pwchange = 1; 194 break; 195 default: /* user can't change(2) or other error (-1) */ 196 logit("Password can't be changed for user %s: %.100s", 197 name, msg); 198 if (msg) 199 xfree(msg); 200 authsuccess = 0; 201 } 202 203 aix_restoreauthdb(); 204 } 205 206 if (authmsg != NULL) 207 xfree(authmsg); 208 209 return authsuccess; 210} 211 212/* 213 * Check if specified account is permitted to log in. 214 * Returns 1 if login is allowed, 0 if not allowed. 215 */ 216int 217sys_auth_allowed_user(struct passwd *pw, Buffer *loginmsg) 218{ 219 char *msg = NULL; 220 int result, permitted = 0; 221 struct stat st; 222 223 /* 224 * Don't perform checks for root account (PermitRootLogin controls 225 * logins via * ssh) or if running as non-root user (since 226 * loginrestrictions will always fail due to insufficient privilege). 227 */ 228 if (pw->pw_uid == 0 || geteuid() != 0) { 229 debug3("%s: not checking", __func__); 230 return 1; 231 } 232 233 result = loginrestrictions(pw->pw_name, S_RLOGIN, NULL, &msg); 234 if (result == 0) 235 permitted = 1; 236 /* 237 * If restricted because /etc/nologin exists, the login will be denied 238 * in session.c after the nologin message is sent, so allow for now 239 * and do not append the returned message. 240 */ 241 if (result == -1 && errno == EPERM && stat(_PATH_NOLOGIN, &st) == 0) 242 permitted = 1; 243 else if (msg != NULL) 244 buffer_append(loginmsg, msg, strlen(msg)); 245 if (msg == NULL) 246 msg = xstrdup("(none)"); 247 aix_remove_embedded_newlines(msg); 248 debug3("AIX/loginrestrictions returned %d msg %.100s", result, msg); 249 250 if (!permitted) 251 logit("Login restricted for %s: %.100s", pw->pw_name, msg); 252 xfree(msg); 253 return permitted; 254} 255 256int 257sys_auth_record_login(const char *user, const char *host, const char *ttynm, 258 Buffer *loginmsg) 259{ 260 char *msg; 261 int success = 0; 262 263 aix_setauthdb(user); 264 if (loginsuccess((char *)user, (char *)host, (char *)ttynm, &msg) == 0) { 265 success = 1; 266 if (msg != NULL) { 267 debug("AIX/loginsuccess: msg %s", msg); 268 buffer_append(loginmsg, msg, strlen(msg)); 269 xfree(msg); 270 } 271 } 272 aix_restoreauthdb(); 273 return (success); 274} 275 276# ifdef CUSTOM_FAILED_LOGIN 277/* 278 * record_failed_login: generic "login failed" interface function 279 */ 280void 281record_failed_login(const char *user, const char *hostname, const char *ttyname) 282{ 283 if (geteuid() != 0) 284 return; 285 286 aix_setauthdb(user); 287# ifdef AIX_LOGINFAILED_4ARG 288 loginfailed((char *)user, (char *)hostname, (char *)ttyname, 289 AUDIT_FAIL_AUTH); 290# else 291 loginfailed((char *)user, (char *)hostname, (char *)ttyname); 292# endif 293 aix_restoreauthdb(); 294} 295# endif /* CUSTOM_FAILED_LOGIN */ 296 297/* 298 * If we have setauthdb, retrieve the password registry for the user's 299 * account then feed it to setauthdb. This will mean that subsequent AIX auth 300 * functions will only use the specified loadable module. If we don't have 301 * setauthdb this is a no-op. 302 */ 303void 304aix_setauthdb(const char *user) 305{ 306# ifdef HAVE_SETAUTHDB 307 char *registry; 308 309 if (setuserdb(S_READ) == -1) { 310 debug3("%s: Could not open userdb to read", __func__); 311 return; 312 } 313 314 if (getuserattr((char *)user, S_REGISTRY, ®istry, SEC_CHAR) == 0) { 315 if (setauthdb(registry, old_registry) == 0) 316 debug3("AIX/setauthdb set registry '%s'", registry); 317 else 318 debug3("AIX/setauthdb set registry '%s' failed: %s", 319 registry, strerror(errno)); 320 } else 321 debug3("%s: Could not read S_REGISTRY for user: %s", __func__, 322 strerror(errno)); 323 enduserdb(); 324# endif /* HAVE_SETAUTHDB */ 325} 326 327/* 328 * Restore the user's registry settings from old_registry. 329 * Note that if the first aix_setauthdb fails, setauthdb("") is still safe 330 * (it restores the system default behaviour). If we don't have setauthdb, 331 * this is a no-op. 332 */ 333void 334aix_restoreauthdb(void) 335{ 336# ifdef HAVE_SETAUTHDB 337 if (setauthdb(old_registry, NULL) == 0) 338 debug3("%s: restoring old registry '%s'", __func__, 339 old_registry); 340 else 341 debug3("%s: failed to restore old registry %s", __func__, 342 old_registry); 343# endif /* HAVE_SETAUTHDB */ 344} 345 346# endif /* WITH_AIXAUTHENTICATE */ 347 348# if defined(AIX_GETNAMEINFO_HACK) && !defined(BROKEN_ADDRINFO) 349# undef getnameinfo 350/* 351 * For some reason, AIX's getnameinfo will refuse to resolve the all-zeros 352 * IPv6 address into its textual representation ("::"), so we wrap it 353 * with a function that will. 354 */ 355int 356sshaix_getnameinfo(const struct sockaddr *sa, size_t salen, char *host, 357 size_t hostlen, char *serv, size_t servlen, int flags) 358{ 359 struct sockaddr_in6 *sa6; 360 u_int32_t *a6; 361 362 if (flags & (NI_NUMERICHOST|NI_NUMERICSERV) && 363 sa->sa_family == AF_INET6) { 364 sa6 = (struct sockaddr_in6 *)sa; 365 a6 = sa6->sin6_addr.u6_addr.u6_addr32; 366 367 if (a6[0] == 0 && a6[1] == 0 && a6[2] == 0 && a6[3] == 0) { 368 strlcpy(host, "::", hostlen); 369 snprintf(serv, servlen, "%d", sa6->sin6_port); 370 return 0; 371 } 372 } 373 return getnameinfo(sa, salen, host, hostlen, serv, servlen, flags); 374} 375# endif /* AIX_GETNAMEINFO_HACK */ 376 377#endif /* _AIX */ 378