diff options
Diffstat (limited to 'other/openssh-2.1.1p4/auth-krb4.c')
| -rw-r--r-- | other/openssh-2.1.1p4/auth-krb4.c | 351 |
1 files changed, 351 insertions, 0 deletions
diff --git a/other/openssh-2.1.1p4/auth-krb4.c b/other/openssh-2.1.1p4/auth-krb4.c new file mode 100644 index 0000000..e32089b --- /dev/null +++ b/other/openssh-2.1.1p4/auth-krb4.c | |||
| @@ -0,0 +1,351 @@ | |||
| 1 | /* | ||
| 2 | * Dug Song <dugsong@UMICH.EDU> | ||
| 3 | * Kerberos v4 authentication and ticket-passing routines. | ||
| 4 | */ | ||
| 5 | |||
| 6 | #include "includes.h" | ||
| 7 | #include "packet.h" | ||
| 8 | #include "xmalloc.h" | ||
| 9 | #include "ssh.h" | ||
| 10 | #include "servconf.h" | ||
| 11 | |||
| 12 | RCSID("$OpenBSD: auth-krb4.c,v 1.15 2000/06/22 23:54:59 djm Exp $"); | ||
| 13 | |||
| 14 | #ifdef KRB4 | ||
| 15 | char *ticket = NULL; | ||
| 16 | |||
| 17 | extern ServerOptions options; | ||
| 18 | |||
| 19 | /* | ||
| 20 | * try krb4 authentication, | ||
| 21 | * return 1 on success, 0 on failure, -1 if krb4 is not available | ||
| 22 | */ | ||
| 23 | |||
| 24 | int | ||
| 25 | auth_krb4_password(struct passwd * pw, const char *password) | ||
| 26 | { | ||
| 27 | AUTH_DAT adata; | ||
| 28 | KTEXT_ST tkt; | ||
| 29 | struct hostent *hp; | ||
| 30 | unsigned long faddr; | ||
| 31 | char localhost[MAXHOSTNAMELEN]; | ||
| 32 | char phost[INST_SZ]; | ||
| 33 | char realm[REALM_SZ]; | ||
| 34 | int r; | ||
| 35 | |||
| 36 | /* | ||
| 37 | * Try Kerberos password authentication only for non-root | ||
| 38 | * users and only if Kerberos is installed. | ||
| 39 | */ | ||
| 40 | if (pw->pw_uid != 0 && krb_get_lrealm(realm, 1) == KSUCCESS) { | ||
| 41 | |||
| 42 | /* Set up our ticket file. */ | ||
| 43 | if (!krb4_init(pw->pw_uid)) { | ||
| 44 | log("Couldn't initialize Kerberos ticket file for %s!", | ||
| 45 | pw->pw_name); | ||
| 46 | goto kerberos_auth_failure; | ||
| 47 | } | ||
| 48 | /* Try to get TGT using our password. */ | ||
| 49 | r = krb_get_pw_in_tkt((char *) pw->pw_name, "", | ||
| 50 | realm, "krbtgt", realm, | ||
| 51 | DEFAULT_TKT_LIFE, (char *) password); | ||
| 52 | if (r != INTK_OK) { | ||
| 53 | packet_send_debug("Kerberos V4 password " | ||
| 54 | "authentication for %s failed: %s", | ||
| 55 | pw->pw_name, krb_err_txt[r]); | ||
| 56 | goto kerberos_auth_failure; | ||
| 57 | } | ||
| 58 | /* Successful authentication. */ | ||
| 59 | chown(tkt_string(), pw->pw_uid, pw->pw_gid); | ||
| 60 | |||
| 61 | /* | ||
| 62 | * Now that we have a TGT, try to get a local | ||
| 63 | * "rcmd" ticket to ensure that we are not talking | ||
| 64 | * to a bogus Kerberos server. | ||
| 65 | */ | ||
| 66 | (void) gethostname(localhost, sizeof(localhost)); | ||
| 67 | (void) strlcpy(phost, (char *) krb_get_phost(localhost), | ||
| 68 | INST_SZ); | ||
| 69 | r = krb_mk_req(&tkt, KRB4_SERVICE_NAME, phost, realm, 33); | ||
| 70 | |||
| 71 | if (r == KSUCCESS) { | ||
| 72 | if (!(hp = gethostbyname(localhost))) { | ||
| 73 | log("Couldn't get local host address!"); | ||
| 74 | goto kerberos_auth_failure; | ||
| 75 | } | ||
| 76 | memmove((void *) &faddr, (void *) hp->h_addr, | ||
| 77 | sizeof(faddr)); | ||
| 78 | |||
| 79 | /* Verify our "rcmd" ticket. */ | ||
| 80 | r = krb_rd_req(&tkt, KRB4_SERVICE_NAME, phost, | ||
| 81 | faddr, &adata, ""); | ||
| 82 | if (r == RD_AP_UNDEC) { | ||
| 83 | /* | ||
| 84 | * Probably didn't have a srvtab on | ||
| 85 | * localhost. Allow login. | ||
| 86 | */ | ||
| 87 | log("Kerberos V4 TGT for %s unverifiable, " | ||
| 88 | "no srvtab installed? krb_rd_req: %s", | ||
| 89 | pw->pw_name, krb_err_txt[r]); | ||
| 90 | } else if (r != KSUCCESS) { | ||
| 91 | log("Kerberos V4 %s ticket unverifiable: %s", | ||
| 92 | KRB4_SERVICE_NAME, krb_err_txt[r]); | ||
| 93 | goto kerberos_auth_failure; | ||
| 94 | } | ||
| 95 | } else if (r == KDC_PR_UNKNOWN) { | ||
| 96 | /* | ||
| 97 | * Allow login if no rcmd service exists, but | ||
| 98 | * log the error. | ||
| 99 | */ | ||
| 100 | log("Kerberos V4 TGT for %s unverifiable: %s; %s.%s " | ||
| 101 | "not registered, or srvtab is wrong?", pw->pw_name, | ||
| 102 | krb_err_txt[r], KRB4_SERVICE_NAME, phost); | ||
| 103 | } else { | ||
| 104 | /* | ||
| 105 | * TGT is bad, forget it. Possibly spoofed! | ||
| 106 | */ | ||
| 107 | packet_send_debug("WARNING: Kerberos V4 TGT " | ||
| 108 | "possibly spoofed for %s: %s", | ||
| 109 | pw->pw_name, krb_err_txt[r]); | ||
| 110 | goto kerberos_auth_failure; | ||
| 111 | } | ||
| 112 | |||
| 113 | /* Authentication succeeded. */ | ||
| 114 | return 1; | ||
| 115 | |||
| 116 | kerberos_auth_failure: | ||
| 117 | krb4_cleanup_proc(NULL); | ||
| 118 | |||
| 119 | if (!options.kerberos_or_local_passwd) | ||
| 120 | return 0; | ||
| 121 | } else { | ||
| 122 | /* Logging in as root or no local Kerberos realm. */ | ||
| 123 | packet_send_debug("Unable to authenticate to Kerberos."); | ||
| 124 | } | ||
| 125 | /* Fall back to ordinary passwd authentication. */ | ||
| 126 | return -1; | ||
| 127 | } | ||
| 128 | |||
| 129 | void | ||
| 130 | krb4_cleanup_proc(void *ignore) | ||
| 131 | { | ||
| 132 | debug("krb4_cleanup_proc called"); | ||
| 133 | if (ticket) { | ||
| 134 | (void) dest_tkt(); | ||
| 135 | xfree(ticket); | ||
| 136 | ticket = NULL; | ||
| 137 | } | ||
| 138 | } | ||
| 139 | |||
| 140 | int | ||
| 141 | krb4_init(uid_t uid) | ||
| 142 | { | ||
| 143 | static int cleanup_registered = 0; | ||
| 144 | const char *tkt_root = TKT_ROOT; | ||
| 145 | struct stat st; | ||
| 146 | int fd; | ||
| 147 | |||
| 148 | if (!ticket) { | ||
| 149 | /* Set unique ticket string manually since we're still root. */ | ||
| 150 | ticket = xmalloc(MAXPATHLEN); | ||
| 151 | #ifdef AFS | ||
| 152 | if (lstat("/ticket", &st) != -1) | ||
| 153 | tkt_root = "/ticket/"; | ||
| 154 | #endif /* AFS */ | ||
| 155 | snprintf(ticket, MAXPATHLEN, "%s%d_%d", tkt_root, uid, getpid()); | ||
| 156 | (void) krb_set_tkt_string(ticket); | ||
| 157 | } | ||
| 158 | /* Register ticket cleanup in case of fatal error. */ | ||
| 159 | if (!cleanup_registered) { | ||
| 160 | fatal_add_cleanup(krb4_cleanup_proc, NULL); | ||
| 161 | cleanup_registered = 1; | ||
| 162 | } | ||
| 163 | /* Try to create our ticket file. */ | ||
| 164 | if ((fd = mkstemp(ticket)) != -1) { | ||
| 165 | close(fd); | ||
| 166 | return 1; | ||
| 167 | } | ||
| 168 | /* Ticket file exists - make sure user owns it (just passed ticket). */ | ||
| 169 | if (lstat(ticket, &st) != -1) { | ||
| 170 | if (st.st_mode == (S_IFREG | S_IRUSR | S_IWUSR) && | ||
| 171 | st.st_uid == uid) | ||
| 172 | return 1; | ||
| 173 | } | ||
| 174 | /* Failure - cancel cleanup function, leaving bad ticket for inspection. */ | ||
| 175 | log("WARNING: bad ticket file %s", ticket); | ||
| 176 | fatal_remove_cleanup(krb4_cleanup_proc, NULL); | ||
| 177 | cleanup_registered = 0; | ||
| 178 | xfree(ticket); | ||
| 179 | ticket = NULL; | ||
| 180 | |||
| 181 | return 0; | ||
| 182 | } | ||
| 183 | |||
| 184 | int | ||
| 185 | auth_krb4(const char *server_user, KTEXT auth, char **client) | ||
| 186 | { | ||
| 187 | AUTH_DAT adat = {0}; | ||
| 188 | KTEXT_ST reply; | ||
| 189 | char instance[INST_SZ]; | ||
| 190 | int r, s; | ||
| 191 | socklen_t slen; | ||
| 192 | u_int cksum; | ||
| 193 | Key_schedule schedule; | ||
| 194 | struct sockaddr_in local, foreign; | ||
| 195 | |||
| 196 | s = packet_get_connection_in(); | ||
| 197 | |||
| 198 | slen = sizeof(local); | ||
| 199 | memset(&local, 0, sizeof(local)); | ||
| 200 | if (getsockname(s, (struct sockaddr *) & local, &slen) < 0) | ||
| 201 | debug("getsockname failed: %.100s", strerror(errno)); | ||
| 202 | slen = sizeof(foreign); | ||
| 203 | memset(&foreign, 0, sizeof(foreign)); | ||
| 204 | if (getpeername(s, (struct sockaddr *) & foreign, &slen) < 0) { | ||
| 205 | debug("getpeername failed: %.100s", strerror(errno)); | ||
| 206 | fatal_cleanup(); | ||
| 207 | } | ||
| 208 | instance[0] = '*'; | ||
| 209 | instance[1] = 0; | ||
| 210 | |||
| 211 | /* Get the encrypted request, challenge, and session key. */ | ||
| 212 | if ((r = krb_rd_req(auth, KRB4_SERVICE_NAME, instance, 0, &adat, ""))) { | ||
| 213 | packet_send_debug("Kerberos V4 krb_rd_req: %.100s", krb_err_txt[r]); | ||
| 214 | return 0; | ||
| 215 | } | ||
| 216 | des_key_sched((des_cblock *) adat.session, schedule); | ||
| 217 | |||
| 218 | *client = xmalloc(MAX_K_NAME_SZ); | ||
| 219 | (void) snprintf(*client, MAX_K_NAME_SZ, "%s%s%s@%s", adat.pname, | ||
| 220 | *adat.pinst ? "." : "", adat.pinst, adat.prealm); | ||
| 221 | |||
| 222 | /* Check ~/.klogin authorization now. */ | ||
| 223 | if (kuserok(&adat, (char *) server_user) != KSUCCESS) { | ||
| 224 | packet_send_debug("Kerberos V4 .klogin authorization failed!"); | ||
| 225 | log("Kerberos V4 .klogin authorization failed for %s to account %s", | ||
| 226 | *client, server_user); | ||
| 227 | xfree(*client); | ||
| 228 | return 0; | ||
| 229 | } | ||
| 230 | /* Increment the checksum, and return it encrypted with the | ||
| 231 | session key. */ | ||
| 232 | cksum = adat.checksum + 1; | ||
| 233 | cksum = htonl(cksum); | ||
| 234 | |||
| 235 | /* If we can't successfully encrypt the checksum, we send back an | ||
| 236 | empty message, admitting our failure. */ | ||
| 237 | if ((r = krb_mk_priv((u_char *) & cksum, reply.dat, sizeof(cksum) + 1, | ||
| 238 | schedule, &adat.session, &local, &foreign)) < 0) { | ||
| 239 | packet_send_debug("Kerberos V4 mk_priv: (%d) %s", r, krb_err_txt[r]); | ||
| 240 | reply.dat[0] = 0; | ||
| 241 | reply.length = 0; | ||
| 242 | } else | ||
| 243 | reply.length = r; | ||
| 244 | |||
| 245 | /* Clear session key. */ | ||
| 246 | memset(&adat.session, 0, sizeof(&adat.session)); | ||
| 247 | |||
| 248 | packet_start(SSH_SMSG_AUTH_KERBEROS_RESPONSE); | ||
| 249 | packet_put_string((char *) reply.dat, reply.length); | ||
| 250 | packet_send(); | ||
| 251 | packet_write_wait(); | ||
| 252 | return 1; | ||
| 253 | } | ||
| 254 | #endif /* KRB4 */ | ||
| 255 | |||
| 256 | #ifdef AFS | ||
| 257 | int | ||
| 258 | auth_kerberos_tgt(struct passwd *pw, const char *string) | ||
| 259 | { | ||
| 260 | CREDENTIALS creds; | ||
| 261 | |||
| 262 | if (!radix_to_creds(string, &creds)) { | ||
| 263 | log("Protocol error decoding Kerberos V4 tgt"); | ||
| 264 | packet_send_debug("Protocol error decoding Kerberos V4 tgt"); | ||
| 265 | goto auth_kerberos_tgt_failure; | ||
| 266 | } | ||
| 267 | if (strncmp(creds.service, "", 1) == 0) /* backward compatibility */ | ||
| 268 | strlcpy(creds.service, "krbtgt", sizeof creds.service); | ||
| 269 | |||
| 270 | if (strcmp(creds.service, "krbtgt")) { | ||
| 271 | log("Kerberos V4 tgt (%s%s%s@%s) rejected for %s", creds.pname, | ||
| 272 | creds.pinst[0] ? "." : "", creds.pinst, creds.realm, | ||
| 273 | pw->pw_name); | ||
| 274 | packet_send_debug("Kerberos V4 tgt (%s%s%s@%s) rejected for %s", | ||
| 275 | creds.pname, creds.pinst[0] ? "." : "", creds.pinst, | ||
| 276 | creds.realm, pw->pw_name); | ||
| 277 | goto auth_kerberos_tgt_failure; | ||
| 278 | } | ||
| 279 | if (!krb4_init(pw->pw_uid)) | ||
| 280 | goto auth_kerberos_tgt_failure; | ||
| 281 | |||
| 282 | if (in_tkt(creds.pname, creds.pinst) != KSUCCESS) | ||
| 283 | goto auth_kerberos_tgt_failure; | ||
| 284 | |||
| 285 | if (save_credentials(creds.service, creds.instance, creds.realm, | ||
| 286 | creds.session, creds.lifetime, creds.kvno, | ||
| 287 | &creds.ticket_st, creds.issue_date) != KSUCCESS) { | ||
| 288 | packet_send_debug("Kerberos V4 tgt refused: couldn't save credentials"); | ||
| 289 | goto auth_kerberos_tgt_failure; | ||
| 290 | } | ||
| 291 | /* Successful authentication, passed all checks. */ | ||
| 292 | chown(tkt_string(), pw->pw_uid, pw->pw_gid); | ||
| 293 | |||
| 294 | packet_send_debug("Kerberos V4 tgt accepted (%s.%s@%s, %s%s%s@%s)", | ||
| 295 | creds.service, creds.instance, creds.realm, creds.pname, | ||
| 296 | creds.pinst[0] ? "." : "", creds.pinst, creds.realm); | ||
| 297 | memset(&creds, 0, sizeof(creds)); | ||
| 298 | packet_start(SSH_SMSG_SUCCESS); | ||
| 299 | packet_send(); | ||
| 300 | packet_write_wait(); | ||
| 301 | return 1; | ||
| 302 | |||
| 303 | auth_kerberos_tgt_failure: | ||
| 304 | krb4_cleanup_proc(NULL); | ||
| 305 | memset(&creds, 0, sizeof(creds)); | ||
| 306 | packet_start(SSH_SMSG_FAILURE); | ||
| 307 | packet_send(); | ||
| 308 | packet_write_wait(); | ||
| 309 | return 0; | ||
| 310 | } | ||
| 311 | |||
| 312 | int | ||
| 313 | auth_afs_token(struct passwd *pw, const char *token_string) | ||
| 314 | { | ||
| 315 | CREDENTIALS creds; | ||
| 316 | uid_t uid = pw->pw_uid; | ||
| 317 | |||
| 318 | if (!radix_to_creds(token_string, &creds)) { | ||
| 319 | log("Protocol error decoding AFS token"); | ||
| 320 | packet_send_debug("Protocol error decoding AFS token"); | ||
| 321 | packet_start(SSH_SMSG_FAILURE); | ||
| 322 | packet_send(); | ||
| 323 | packet_write_wait(); | ||
| 324 | return 0; | ||
| 325 | } | ||
| 326 | if (strncmp(creds.service, "", 1) == 0) /* backward compatibility */ | ||
| 327 | strlcpy(creds.service, "afs", sizeof creds.service); | ||
| 328 | |||
| 329 | if (strncmp(creds.pname, "AFS ID ", 7) == 0) | ||
| 330 | uid = atoi(creds.pname + 7); | ||
| 331 | |||
| 332 | if (kafs_settoken(creds.realm, uid, &creds)) { | ||
| 333 | log("AFS token (%s@%s) rejected for %s", creds.pname, creds.realm, | ||
| 334 | pw->pw_name); | ||
| 335 | packet_send_debug("AFS token (%s@%s) rejected for %s", creds.pname, | ||
| 336 | creds.realm, pw->pw_name); | ||
| 337 | memset(&creds, 0, sizeof(creds)); | ||
| 338 | packet_start(SSH_SMSG_FAILURE); | ||
| 339 | packet_send(); | ||
| 340 | packet_write_wait(); | ||
| 341 | return 0; | ||
| 342 | } | ||
| 343 | packet_send_debug("AFS token accepted (%s@%s, %s@%s)", creds.service, | ||
| 344 | creds.realm, creds.pname, creds.realm); | ||
| 345 | memset(&creds, 0, sizeof(creds)); | ||
| 346 | packet_start(SSH_SMSG_SUCCESS); | ||
| 347 | packet_send(); | ||
| 348 | packet_write_wait(); | ||
| 349 | return 1; | ||
| 350 | } | ||
| 351 | #endif /* AFS */ | ||
