| 1 | /************************************************* |
| 2 | * Exim - an Internet mail transport agent * |
| 3 | *************************************************/ |
| 4 | |
| 5 | /* Copyright (c) University of Cambridge 1995 - 2012 */ |
| 6 | /* See the file NOTICE for conditions of use and distribution. */ |
| 7 | |
| 8 | /* Copyright (c) Twitter Inc 2012 |
| 9 | Author: Phil Pennock <pdp@exim.org> */ |
| 10 | /* Copyright (c) Phil Pennock 2012 */ |
| 11 | |
| 12 | /* Interface to Heimdal library for GSSAPI authentication. */ |
| 13 | |
| 14 | /* Naming and rationale |
| 15 | |
| 16 | Sensibly, this integration would be deferred to a SASL library, but none |
| 17 | of them appear to offer keytab file selection interfaces in their APIs. It |
| 18 | might be that this driver only requires minor modification to work with MIT |
| 19 | Kerberos. |
| 20 | |
| 21 | Heimdal provides a number of interfaces for various forms of authentication. |
| 22 | As GS2 does not appear to provide keytab control interfaces either, we may |
| 23 | end up supporting that too. It's possible that we could trivially expand to |
| 24 | support NTLM support via Heimdal, etc. Rather than try to be too generic |
| 25 | immediately, this driver is directly only supporting GSSAPI. |
| 26 | |
| 27 | Without rename, we could add an option for GS2 support in the future. |
| 28 | */ |
| 29 | |
| 30 | /* Sources |
| 31 | |
| 32 | * mailcheck-imap (Perl, client-side, written by me years ago) |
| 33 | * gsasl driver (GPL, server-side) |
| 34 | * heimdal sources and man-pages, plus http://www.h5l.org/manual/ |
| 35 | * FreeBSD man-pages (very informative!) |
| 36 | * http://www.ggf.org/documents/GFD.24.pdf confirming GSS_KRB5_REGISTER_ACCEPTOR_IDENTITY_X |
| 37 | semantics, that found by browsing Heimdal source to find how to set the keytab; however, |
| 38 | after multiple attempts I failed to get that to work and instead switched to |
| 39 | gsskrb5_register_acceptor_identity(). |
| 40 | */ |
| 41 | |
| 42 | #include "../exim.h" |
| 43 | |
| 44 | #ifndef AUTH_HEIMDAL_GSSAPI |
| 45 | /* dummy function to satisfy compilers when we link in an "empty" file. */ |
| 46 | static void dummy(int x) { dummy(x-1); } |
| 47 | #else |
| 48 | |
| 49 | #include <gssapi/gssapi.h> |
| 50 | #include <gssapi/gssapi_krb5.h> |
| 51 | |
| 52 | /* for the _init debugging */ |
| 53 | #include <krb5.h> |
| 54 | |
| 55 | #include "heimdal_gssapi.h" |
| 56 | |
| 57 | /* Authenticator-specific options. */ |
| 58 | optionlist auth_heimdal_gssapi_options[] = { |
| 59 | { "server_hostname", opt_stringptr, |
| 60 | (void *)(offsetof(auth_heimdal_gssapi_options_block, server_hostname)) }, |
| 61 | { "server_keytab", opt_stringptr, |
| 62 | (void *)(offsetof(auth_heimdal_gssapi_options_block, server_keytab)) }, |
| 63 | { "server_service", opt_stringptr, |
| 64 | (void *)(offsetof(auth_heimdal_gssapi_options_block, server_service)) } |
| 65 | }; |
| 66 | |
| 67 | int auth_heimdal_gssapi_options_count = |
| 68 | sizeof(auth_heimdal_gssapi_options)/sizeof(optionlist); |
| 69 | |
| 70 | /* Defaults for the authenticator-specific options. */ |
| 71 | auth_heimdal_gssapi_options_block auth_heimdal_gssapi_option_defaults = { |
| 72 | US"$primary_hostname", /* server_hostname */ |
| 73 | NULL, /* server_keytab */ |
| 74 | US"smtp", /* server_service */ |
| 75 | }; |
| 76 | |
| 77 | /* "Globals" for managing the heimdal_gssapi interface. */ |
| 78 | |
| 79 | /* Utility functions */ |
| 80 | static void |
| 81 | exim_heimdal_error_debug(const char *, krb5_context, krb5_error_code); |
| 82 | static int |
| 83 | exim_gssapi_error_defer(uschar *, OM_uint32, OM_uint32, const char *, ...) |
| 84 | PRINTF_FUNCTION(4, 5); |
| 85 | |
| 86 | #define EmptyBuf(buf) do { buf.value = NULL; buf.length = 0; } while (0) |
| 87 | |
| 88 | |
| 89 | /************************************************* |
| 90 | * Initialization entry point * |
| 91 | *************************************************/ |
| 92 | |
| 93 | /* Called for each instance, after its options have been read, to |
| 94 | enable consistency checks to be done, or anything else that needs |
| 95 | to be set up. */ |
| 96 | |
| 97 | /* Heimdal provides a GSSAPI extension method for setting the keytab; |
| 98 | in the init, we mostly just use raw krb5 methods so that we can report |
| 99 | the keytab contents, for -D+auth debugging. */ |
| 100 | |
| 101 | void |
| 102 | auth_heimdal_gssapi_init(auth_instance *ablock) |
| 103 | { |
| 104 | krb5_context context; |
| 105 | krb5_keytab keytab; |
| 106 | krb5_kt_cursor cursor; |
| 107 | krb5_keytab_entry entry; |
| 108 | krb5_error_code krc; |
| 109 | char *principal, *enctype_s; |
| 110 | const char *k_keytab_typed_name = NULL; |
| 111 | auth_heimdal_gssapi_options_block *ob = |
| 112 | (auth_heimdal_gssapi_options_block *)(ablock->options_block); |
| 113 | |
| 114 | ablock->server = FALSE; |
| 115 | ablock->client = FALSE; |
| 116 | |
| 117 | if (!ob->server_service || !*ob->server_service) { |
| 118 | HDEBUG(D_auth) debug_printf("heimdal: missing server_service\n"); |
| 119 | return; |
| 120 | } |
| 121 | |
| 122 | krc = krb5_init_context(&context); |
| 123 | if (krc != 0) { |
| 124 | int kerr = errno; |
| 125 | HDEBUG(D_auth) debug_printf("heimdal: failed to initialise krb5 context: %s\n", |
| 126 | strerror(kerr)); |
| 127 | return; |
| 128 | } |
| 129 | |
| 130 | if (ob->server_keytab) { |
| 131 | k_keytab_typed_name = CCS string_sprintf("file:%s", expand_string(ob->server_keytab)); |
| 132 | HDEBUG(D_auth) debug_printf("heimdal: using keytab %s\n", k_keytab_typed_name); |
| 133 | krc = krb5_kt_resolve(context, k_keytab_typed_name, &keytab); |
| 134 | if (krc) { |
| 135 | HDEBUG(D_auth) exim_heimdal_error_debug("krb5_kt_resolve", context, krc); |
| 136 | return; |
| 137 | } |
| 138 | } else { |
| 139 | HDEBUG(D_auth) debug_printf("heimdal: using system default keytab\n"); |
| 140 | krc = krb5_kt_default(context, &keytab); |
| 141 | if (krc) { |
| 142 | HDEBUG(D_auth) exim_heimdal_error_debug("krb5_kt_default", context, krc); |
| 143 | return; |
| 144 | } |
| 145 | } |
| 146 | |
| 147 | HDEBUG(D_auth) { |
| 148 | /* http://www.h5l.org/manual/HEAD/krb5/krb5_keytab_intro.html */ |
| 149 | krc = krb5_kt_start_seq_get(context, keytab, &cursor); |
| 150 | if (krc) |
| 151 | exim_heimdal_error_debug("krb5_kt_start_seq_get", context, krc); |
| 152 | else { |
| 153 | while ((krc = krb5_kt_next_entry(context, keytab, &entry, &cursor)) == 0) { |
| 154 | principal = enctype_s = NULL; |
| 155 | krb5_unparse_name(context, entry.principal, &principal); |
| 156 | krb5_enctype_to_string(context, entry.keyblock.keytype, &enctype_s); |
| 157 | debug_printf("heimdal: keytab principal: %s vno=%d type=%s\n", |
| 158 | principal ? principal : "??", |
| 159 | entry.vno, |
| 160 | enctype_s ? enctype_s : "??"); |
| 161 | free(principal); |
| 162 | free(enctype_s); |
| 163 | krb5_kt_free_entry(context, &entry); |
| 164 | } |
| 165 | krc = krb5_kt_end_seq_get(context, keytab, &cursor); |
| 166 | if (krc) |
| 167 | exim_heimdal_error_debug("krb5_kt_end_seq_get", context, krc); |
| 168 | } |
| 169 | } |
| 170 | |
| 171 | krc = krb5_kt_close(context, keytab); |
| 172 | if (krc) |
| 173 | HDEBUG(D_auth) exim_heimdal_error_debug("krb5_kt_close", context, krc); |
| 174 | |
| 175 | krb5_free_context(context); |
| 176 | |
| 177 | /* RFC 4121 section 5.2, SHOULD support 64K input buffers */ |
| 178 | if (big_buffer_size < (64 * 1024)) { |
| 179 | uschar *newbuf; |
| 180 | big_buffer_size = 64 * 1024; |
| 181 | newbuf = store_malloc(big_buffer_size); |
| 182 | store_free(big_buffer); |
| 183 | big_buffer = newbuf; |
| 184 | } |
| 185 | |
| 186 | ablock->server = TRUE; |
| 187 | } |
| 188 | |
| 189 | |
| 190 | static void |
| 191 | exim_heimdal_error_debug(const char *label, |
| 192 | krb5_context context, krb5_error_code err) |
| 193 | { |
| 194 | const char *kerrsc; |
| 195 | kerrsc = krb5_get_error_message(context, err); |
| 196 | debug_printf("heimdal %s: %s\n", label, kerrsc ? kerrsc : "unknown error"); |
| 197 | krb5_free_error_message(context, kerrsc); |
| 198 | } |
| 199 | |
| 200 | /************************************************* |
| 201 | * Server entry point * |
| 202 | *************************************************/ |
| 203 | |
| 204 | /* For interface, see auths/README */ |
| 205 | |
| 206 | /* GSSAPI notes: |
| 207 | OM_uint32: portable type for unsigned int32 |
| 208 | gss_buffer_desc / *gss_buffer_t: hold/point-to size_t .length & void *value |
| 209 | -- all strings/etc passed in should go through one of these |
| 210 | -- when allocated by gssapi, release with gss_release_buffer() |
| 211 | */ |
| 212 | |
| 213 | int |
| 214 | auth_heimdal_gssapi_server(auth_instance *ablock, uschar *initial_data) |
| 215 | { |
| 216 | gss_name_t gclient = GSS_C_NO_NAME; |
| 217 | gss_name_t gserver = GSS_C_NO_NAME; |
| 218 | gss_cred_id_t gcred = GSS_C_NO_CREDENTIAL; |
| 219 | gss_ctx_id_t gcontext = GSS_C_NO_CONTEXT; |
| 220 | uschar *ex_server_str; |
| 221 | gss_buffer_desc gbufdesc = GSS_C_EMPTY_BUFFER; |
| 222 | gss_buffer_desc gbufdesc_in = GSS_C_EMPTY_BUFFER; |
| 223 | gss_buffer_desc gbufdesc_out = GSS_C_EMPTY_BUFFER; |
| 224 | gss_OID mech_type; |
| 225 | OM_uint32 maj_stat, min_stat; |
| 226 | int step, error_out, i; |
| 227 | uschar *tmp1, *tmp2, *from_client; |
| 228 | auth_heimdal_gssapi_options_block *ob = |
| 229 | (auth_heimdal_gssapi_options_block *)(ablock->options_block); |
| 230 | BOOL handled_empty_ir; |
| 231 | uschar *store_reset_point; |
| 232 | uschar *keytab; |
| 233 | uschar sasl_config[4]; |
| 234 | uschar requested_qop; |
| 235 | |
| 236 | store_reset_point = store_get(0); |
| 237 | |
| 238 | HDEBUG(D_auth) |
| 239 | debug_printf("heimdal: initialising auth context for %s\n", ablock->name); |
| 240 | |
| 241 | /* Construct our gss_name_t gserver describing ourselves */ |
| 242 | tmp1 = expand_string(ob->server_service); |
| 243 | tmp2 = expand_string(ob->server_hostname); |
| 244 | ex_server_str = string_sprintf("%s@%s", tmp1, tmp2); |
| 245 | gbufdesc.value = (void *) ex_server_str; |
| 246 | gbufdesc.length = Ustrlen(ex_server_str); |
| 247 | maj_stat = gss_import_name(&min_stat, |
| 248 | &gbufdesc, GSS_C_NT_HOSTBASED_SERVICE, &gserver); |
| 249 | if (GSS_ERROR(maj_stat)) |
| 250 | return exim_gssapi_error_defer(store_reset_point, maj_stat, min_stat, |
| 251 | "gss_import_name(%s)", CS gbufdesc.value); |
| 252 | |
| 253 | /* Use a specific keytab, if specified */ |
| 254 | if (ob->server_keytab) { |
| 255 | keytab = expand_string(ob->server_keytab); |
| 256 | maj_stat = gsskrb5_register_acceptor_identity(CCS keytab); |
| 257 | if (GSS_ERROR(maj_stat)) |
| 258 | return exim_gssapi_error_defer(store_reset_point, maj_stat, min_stat, |
| 259 | "registering keytab \"%s\"", keytab); |
| 260 | HDEBUG(D_auth) |
| 261 | debug_printf("heimdal: using keytab \"%s\"\n", keytab); |
| 262 | } |
| 263 | |
| 264 | /* Acquire our credentials */ |
| 265 | maj_stat = gss_acquire_cred(&min_stat, |
| 266 | gserver, /* desired name */ |
| 267 | 0, /* time */ |
| 268 | GSS_C_NULL_OID_SET, /* desired mechs */ |
| 269 | GSS_C_ACCEPT, /* cred usage */ |
| 270 | &gcred, /* handle */ |
| 271 | NULL /* actual mechs */, |
| 272 | NULL /* time rec */); |
| 273 | if (GSS_ERROR(maj_stat)) |
| 274 | return exim_gssapi_error_defer(store_reset_point, maj_stat, min_stat, |
| 275 | "gss_acquire_cred(%s)", ex_server_str); |
| 276 | |
| 277 | maj_stat = gss_release_name(&min_stat, &gserver); |
| 278 | |
| 279 | HDEBUG(D_auth) debug_printf("heimdal: have server credentials.\n"); |
| 280 | |
| 281 | /* Loop talking to client */ |
| 282 | step = 0; |
| 283 | from_client = initial_data; |
| 284 | handled_empty_ir = FALSE; |
| 285 | error_out = OK; |
| 286 | |
| 287 | /* buffer sizes: auth_get_data() uses big_buffer, which we grow per |
| 288 | GSSAPI RFC in _init, if needed, to meet the SHOULD size of 64KB. |
| 289 | (big_buffer starts life at the MUST size of 16KB). */ |
| 290 | |
| 291 | /* step values |
| 292 | 0: getting initial data from client to feed into GSSAPI |
| 293 | 1: iterating for as long as GSS_S_CONTINUE_NEEDED |
| 294 | 2: GSS_S_COMPLETE, SASL wrapping for authz and qop to send to client |
| 295 | 3: unpick final auth message from client |
| 296 | 4: break/finish (non-step) |
| 297 | */ |
| 298 | while (step < 4) { |
| 299 | switch (step) { |
| 300 | case 0: |
| 301 | if (!from_client || *from_client == '\0') { |
| 302 | if (handled_empty_ir) { |
| 303 | HDEBUG(D_auth) debug_printf("gssapi: repeated empty input, grr.\n"); |
| 304 | error_out = BAD64; |
| 305 | goto ERROR_OUT; |
| 306 | } else { |
| 307 | HDEBUG(D_auth) debug_printf("gssapi: missing initial response, nudging.\n"); |
| 308 | error_out = auth_get_data(&from_client, US"", 0); |
| 309 | if (error_out != OK) |
| 310 | goto ERROR_OUT; |
| 311 | handled_empty_ir = TRUE; |
| 312 | continue; |
| 313 | } |
| 314 | } |
| 315 | /* We should now have the opening data from the client, base64-encoded. */ |
| 316 | step += 1; |
| 317 | HDEBUG(D_auth) debug_printf("heimdal: have initial client data\n"); |
| 318 | break; |
| 319 | |
| 320 | case 1: |
| 321 | gbufdesc_in.length = auth_b64decode(from_client, USS &gbufdesc_in.value); |
| 322 | if (gclient) { |
| 323 | maj_stat = gss_release_name(&min_stat, &gclient); |
| 324 | gclient = GSS_C_NO_NAME; |
| 325 | } |
| 326 | maj_stat = gss_accept_sec_context(&min_stat, |
| 327 | &gcontext, /* context handle */ |
| 328 | gcred, /* acceptor cred handle */ |
| 329 | &gbufdesc_in, /* input from client */ |
| 330 | GSS_C_NO_CHANNEL_BINDINGS, /* XXX fixme: use the channel bindings from GnuTLS */ |
| 331 | &gclient, /* client identifier */ |
| 332 | &mech_type, /* mechanism in use */ |
| 333 | &gbufdesc_out, /* output to send to client */ |
| 334 | NULL, /* return flags */ |
| 335 | NULL, /* time rec */ |
| 336 | NULL /* delegated cred_handle */ |
| 337 | ); |
| 338 | if (GSS_ERROR(maj_stat)) { |
| 339 | exim_gssapi_error_defer(NULL, maj_stat, min_stat, |
| 340 | "gss_accept_sec_context()"); |
| 341 | error_out = FAIL; |
| 342 | goto ERROR_OUT; |
| 343 | } |
| 344 | if (&gbufdesc_out.length != 0) { |
| 345 | error_out = auth_get_data(&from_client, |
| 346 | gbufdesc_out.value, gbufdesc_out.length); |
| 347 | if (error_out != OK) |
| 348 | goto ERROR_OUT; |
| 349 | |
| 350 | gss_release_buffer(&min_stat, &gbufdesc_out); |
| 351 | EmptyBuf(gbufdesc_out); |
| 352 | } |
| 353 | if (maj_stat == GSS_S_COMPLETE) { |
| 354 | step += 1; |
| 355 | HDEBUG(D_auth) debug_printf("heimdal: GSS complete\n"); |
| 356 | } else { |
| 357 | HDEBUG(D_auth) debug_printf("heimdal: need more data\n"); |
| 358 | } |
| 359 | break; |
| 360 | |
| 361 | case 2: |
| 362 | memset(sasl_config, 0xFF, 4); |
| 363 | /* draft-ietf-sasl-gssapi-06.txt defines bitmasks for first octet |
| 364 | 0x01 No security layer |
| 365 | 0x02 Integrity protection |
| 366 | 0x04 Confidentiality protection |
| 367 | |
| 368 | The remaining three octets are the maximum buffer size for wrapped |
| 369 | content. */ |
| 370 | sasl_config[0] = 0x01; /* Exim does not wrap/unwrap SASL layers after auth */ |
| 371 | gbufdesc.value = (void *) sasl_config; |
| 372 | gbufdesc.length = 4; |
| 373 | maj_stat = gss_wrap(&min_stat, |
| 374 | gcontext, |
| 375 | 0, /* conf_req_flag: integrity only */ |
| 376 | GSS_C_QOP_DEFAULT, /* qop requested */ |
| 377 | &gbufdesc, /* message to protect */ |
| 378 | NULL, /* conf_state: no confidentiality applied */ |
| 379 | &gbufdesc_out /* output buffer */ |
| 380 | ); |
| 381 | if (GSS_ERROR(maj_stat)) { |
| 382 | exim_gssapi_error_defer(NULL, maj_stat, min_stat, |
| 383 | "gss_wrap(SASL state after auth)"); |
| 384 | error_out = FAIL; |
| 385 | goto ERROR_OUT; |
| 386 | } |
| 387 | |
| 388 | HDEBUG(D_auth) debug_printf("heimdal SASL: requesting QOP with no security layers\n"); |
| 389 | |
| 390 | error_out = auth_get_data(&from_client, |
| 391 | gbufdesc_out.value, gbufdesc_out.length); |
| 392 | if (error_out != OK) |
| 393 | goto ERROR_OUT; |
| 394 | |
| 395 | gss_release_buffer(&min_stat, &gbufdesc_out); |
| 396 | EmptyBuf(gbufdesc_out); |
| 397 | step += 1; |
| 398 | break; |
| 399 | |
| 400 | case 3: |
| 401 | gbufdesc_in.length = auth_b64decode(from_client, USS &gbufdesc_in.value); |
| 402 | maj_stat = gss_unwrap(&min_stat, |
| 403 | gcontext, |
| 404 | &gbufdesc_in, /* data from client */ |
| 405 | &gbufdesc_out, /* results */ |
| 406 | NULL, /* conf state */ |
| 407 | NULL /* qop state */ |
| 408 | ); |
| 409 | if (GSS_ERROR(maj_stat)) { |
| 410 | exim_gssapi_error_defer(NULL, maj_stat, min_stat, |
| 411 | "gss_unwrap(final SASL message from client)"); |
| 412 | error_out = FAIL; |
| 413 | goto ERROR_OUT; |
| 414 | } |
| 415 | if (gbufdesc_out.length < 4) { |
| 416 | HDEBUG(D_auth) |
| 417 | debug_printf("gssapi: final message too short; " |
| 418 | "need flags, buf sizes and optional authzid\n"); |
| 419 | error_out = FAIL; |
| 420 | goto ERROR_OUT; |
| 421 | } |
| 422 | |
| 423 | requested_qop = (CS gbufdesc_out.value)[0]; |
| 424 | if ((requested_qop & 0x01) == 0) { |
| 425 | HDEBUG(D_auth) |
| 426 | debug_printf("gssapi: client requested security layers (%x)\n", |
| 427 | (unsigned int) requested_qop); |
| 428 | error_out = FAIL; |
| 429 | goto ERROR_OUT; |
| 430 | } |
| 431 | |
| 432 | for (i = 0; i < AUTH_VARS; i++) auth_vars[i] = NULL; |
| 433 | expand_nmax = 0; |
| 434 | |
| 435 | /* Identifiers: |
| 436 | The SASL provided identifier is an unverified authzid. |
| 437 | GSSAPI provides us with a verified identifier, but it might be empty |
| 438 | for some clients. |
| 439 | */ |
| 440 | |
| 441 | /* $auth2 is authzid requested at SASL layer */ |
| 442 | if (gbufdesc_out.length > 4) { |
| 443 | expand_nlength[2] = gbufdesc_out.length - 4; |
| 444 | auth_vars[1] = expand_nstring[2] = |
| 445 | string_copyn((US gbufdesc_out.value) + 4, expand_nlength[2]); |
| 446 | expand_nmax = 2; |
| 447 | } |
| 448 | |
| 449 | gss_release_buffer(&min_stat, &gbufdesc_out); |
| 450 | EmptyBuf(gbufdesc_out); |
| 451 | |
| 452 | /* $auth1 is GSSAPI display name */ |
| 453 | maj_stat = gss_display_name(&min_stat, |
| 454 | gclient, |
| 455 | &gbufdesc_out, |
| 456 | &mech_type); |
| 457 | if (GSS_ERROR(maj_stat)) { |
| 458 | auth_vars[1] = expand_nstring[2] = NULL; |
| 459 | expand_nmax = 0; |
| 460 | exim_gssapi_error_defer(NULL, maj_stat, min_stat, |
| 461 | "gss_display_name(client identifier)"); |
| 462 | error_out = FAIL; |
| 463 | goto ERROR_OUT; |
| 464 | } |
| 465 | |
| 466 | expand_nlength[1] = gbufdesc_out.length; |
| 467 | auth_vars[0] = expand_nstring[1] = |
| 468 | string_copyn(gbufdesc_out.value, gbufdesc_out.length); |
| 469 | |
| 470 | if (expand_nmax == 0) { /* should be: authzid was empty */ |
| 471 | expand_nmax = 2; |
| 472 | expand_nlength[2] = expand_nlength[1]; |
| 473 | auth_vars[1] = expand_nstring[2] = string_copyn(expand_nstring[1], expand_nlength[1]); |
| 474 | HDEBUG(D_auth) |
| 475 | debug_printf("heimdal SASL: empty authzid, set to dup of GSSAPI display name\n"); |
| 476 | } |
| 477 | |
| 478 | HDEBUG(D_auth) |
| 479 | debug_printf("heimdal SASL: happy with client request\n" |
| 480 | " auth1 (verified GSSAPI display-name): \"%s\"\n" |
| 481 | " auth2 (unverified SASL requested authzid): \"%s\"\n", |
| 482 | auth_vars[0], auth_vars[1]); |
| 483 | |
| 484 | step += 1; |
| 485 | break; |
| 486 | |
| 487 | } /* switch */ |
| 488 | } /* while step */ |
| 489 | |
| 490 | |
| 491 | ERROR_OUT: |
| 492 | maj_stat = gss_release_cred(&min_stat, &gcred); |
| 493 | if (gclient) { |
| 494 | gss_release_name(&min_stat, &gclient); |
| 495 | gclient = GSS_C_NO_NAME; |
| 496 | } |
| 497 | if (gbufdesc_out.length) { |
| 498 | gss_release_buffer(&min_stat, &gbufdesc_out); |
| 499 | EmptyBuf(gbufdesc_out); |
| 500 | } |
| 501 | if (gcontext != GSS_C_NO_CONTEXT) { |
| 502 | gss_delete_sec_context(&min_stat, &gcontext, GSS_C_NO_BUFFER); |
| 503 | } |
| 504 | |
| 505 | store_reset(store_reset_point); |
| 506 | |
| 507 | if (error_out != OK) |
| 508 | return error_out; |
| 509 | |
| 510 | /* Auth succeeded, check server_condition */ |
| 511 | return auth_check_serv_cond(ablock); |
| 512 | } |
| 513 | |
| 514 | |
| 515 | static int |
| 516 | exim_gssapi_error_defer(uschar *store_reset_point, |
| 517 | OM_uint32 major, OM_uint32 minor, |
| 518 | const char *format, ...) |
| 519 | { |
| 520 | va_list ap; |
| 521 | uschar buffer[STRING_SPRINTF_BUFFER_SIZE]; |
| 522 | OM_uint32 maj_stat, min_stat; |
| 523 | OM_uint32 msgcontext = 0; |
| 524 | gss_buffer_desc status_string; |
| 525 | |
| 526 | va_start(ap, format); |
| 527 | if (!string_vformat(buffer, sizeof(buffer), format, ap)) |
| 528 | log_write(0, LOG_MAIN|LOG_PANIC_DIE, |
| 529 | "exim_gssapi_error_defer expansion larger than %lu", |
| 530 | sizeof(buffer)); |
| 531 | va_end(ap); |
| 532 | |
| 533 | auth_defer_msg = NULL; |
| 534 | |
| 535 | do { |
| 536 | maj_stat = gss_display_status(&min_stat, |
| 537 | major, GSS_C_GSS_CODE, GSS_C_NO_OID, |
| 538 | &msgcontext, &status_string); |
| 539 | |
| 540 | if (auth_defer_msg == NULL) { |
| 541 | auth_defer_msg = string_copy(US status_string.value); |
| 542 | } |
| 543 | |
| 544 | HDEBUG(D_auth) debug_printf("heimdal %s: %.*s\n", |
| 545 | buffer, (int)status_string.length, CS status_string.value); |
| 546 | gss_release_buffer(&min_stat, &status_string); |
| 547 | |
| 548 | } while (msgcontext != 0); |
| 549 | |
| 550 | if (store_reset_point) |
| 551 | store_reset(store_reset_point); |
| 552 | return DEFER; |
| 553 | } |
| 554 | |
| 555 | |
| 556 | /************************************************* |
| 557 | * Client entry point * |
| 558 | *************************************************/ |
| 559 | |
| 560 | /* For interface, see auths/README */ |
| 561 | |
| 562 | int |
| 563 | auth_heimdal_gssapi_client( |
| 564 | auth_instance *ablock, /* authenticator block */ |
| 565 | smtp_inblock *inblock, /* connection inblock */ |
| 566 | smtp_outblock *outblock, /* connection outblock */ |
| 567 | int timeout, /* command timeout */ |
| 568 | uschar *buffer, /* buffer for reading response */ |
| 569 | int buffsize) /* size of buffer */ |
| 570 | { |
| 571 | HDEBUG(D_auth) |
| 572 | debug_printf("Client side NOT IMPLEMENTED: you should not see this!\n"); |
| 573 | /* NOT IMPLEMENTED */ |
| 574 | return FAIL; |
| 575 | } |
| 576 | |
| 577 | /************************************************* |
| 578 | * Diagnostic API * |
| 579 | *************************************************/ |
| 580 | |
| 581 | void |
| 582 | auth_heimdal_gssapi_version_report(FILE *f) |
| 583 | { |
| 584 | /* No build-time constants available unless we link against libraries at |
| 585 | build-time and export the result as a string into a header ourselves. */ |
| 586 | fprintf(f, "Library version: Heimdal: Runtime: %s\n" |
| 587 | " Build Info: %s\n", |
| 588 | heimdal_version, heimdal_long_version); |
| 589 | } |
| 590 | |
| 591 | #endif /* AUTH_HEIMDAL_GSSAPI */ |
| 592 | |
| 593 | /* End of heimdal_gssapi.c */ |