| 1 | #ifndef NO_GSSAPI |
| 2 | |
| 3 | #include "putty.h" |
| 4 | |
| 5 | #include <security.h> |
| 6 | |
| 7 | #include "pgssapi.h" |
| 8 | #include "sshgss.h" |
| 9 | #include "sshgssc.h" |
| 10 | |
| 11 | #include "misc.h" |
| 12 | |
| 13 | /* Windows code to set up the GSSAPI library list. */ |
| 14 | |
| 15 | const int ngsslibs = 3; |
| 16 | const char *const gsslibnames[3] = { |
| 17 | "MIT Kerberos GSSAPI32.DLL", |
| 18 | "Microsoft SSPI SECUR32.DLL", |
| 19 | "User-specified GSSAPI DLL", |
| 20 | }; |
| 21 | const struct keyvalwhere gsslibkeywords[] = { |
| 22 | { "gssapi32", 0, -1, -1 }, |
| 23 | { "sspi", 1, -1, -1 }, |
| 24 | { "custom", 2, -1, -1 }, |
| 25 | }; |
| 26 | |
| 27 | DECL_WINDOWS_FUNCTION(static, SECURITY_STATUS, |
| 28 | AcquireCredentialsHandleA, |
| 29 | (SEC_CHAR *, SEC_CHAR *, ULONG, PLUID, |
| 30 | PVOID, SEC_GET_KEY_FN, PVOID, PCredHandle, PTimeStamp)); |
| 31 | DECL_WINDOWS_FUNCTION(static, SECURITY_STATUS, |
| 32 | InitializeSecurityContextA, |
| 33 | (PCredHandle, PCtxtHandle, SEC_CHAR *, ULONG, ULONG, |
| 34 | ULONG, PSecBufferDesc, ULONG, PCtxtHandle, |
| 35 | PSecBufferDesc, PULONG, PTimeStamp)); |
| 36 | DECL_WINDOWS_FUNCTION(static, SECURITY_STATUS, |
| 37 | FreeContextBuffer, |
| 38 | (PVOID)); |
| 39 | DECL_WINDOWS_FUNCTION(static, SECURITY_STATUS, |
| 40 | FreeCredentialsHandle, |
| 41 | (PCredHandle)); |
| 42 | DECL_WINDOWS_FUNCTION(static, SECURITY_STATUS, |
| 43 | DeleteSecurityContext, |
| 44 | (PCtxtHandle)); |
| 45 | DECL_WINDOWS_FUNCTION(static, SECURITY_STATUS, |
| 46 | QueryContextAttributesA, |
| 47 | (PCtxtHandle, ULONG, PVOID)); |
| 48 | DECL_WINDOWS_FUNCTION(static, SECURITY_STATUS, |
| 49 | MakeSignature, |
| 50 | (PCtxtHandle, ULONG, PSecBufferDesc, ULONG)); |
| 51 | |
| 52 | typedef struct winSsh_gss_ctx { |
| 53 | unsigned long maj_stat; |
| 54 | unsigned long min_stat; |
| 55 | CredHandle cred_handle; |
| 56 | CtxtHandle context; |
| 57 | PCtxtHandle context_handle; |
| 58 | TimeStamp expiry; |
| 59 | } winSsh_gss_ctx; |
| 60 | |
| 61 | |
| 62 | const Ssh_gss_buf gss_mech_krb5={9,"\x2A\x86\x48\x86\xF7\x12\x01\x02\x02"}; |
| 63 | |
| 64 | const char *gsslogmsg = NULL; |
| 65 | |
| 66 | static void ssh_sspi_bind_fns(struct ssh_gss_library *lib); |
| 67 | |
| 68 | struct ssh_gss_liblist *ssh_gss_setup(Conf *conf) |
| 69 | { |
| 70 | HMODULE module; |
| 71 | HKEY regkey; |
| 72 | struct ssh_gss_liblist *list = snew(struct ssh_gss_liblist); |
| 73 | char *path; |
| 74 | |
| 75 | list->libraries = snewn(3, struct ssh_gss_library); |
| 76 | list->nlibraries = 0; |
| 77 | |
| 78 | /* MIT Kerberos GSSAPI implementation */ |
| 79 | /* TODO: For 64-bit builds, check for gssapi64.dll */ |
| 80 | module = NULL; |
| 81 | if (RegOpenKey(HKEY_LOCAL_MACHINE, "SOFTWARE\\MIT\\Kerberos", ®key) |
| 82 | == ERROR_SUCCESS) { |
| 83 | DWORD type, size; |
| 84 | LONG ret; |
| 85 | char *buffer; |
| 86 | |
| 87 | /* Find out the string length */ |
| 88 | ret = RegQueryValueEx(regkey, "InstallDir", NULL, &type, NULL, &size); |
| 89 | |
| 90 | if (ret == ERROR_SUCCESS && type == REG_SZ) { |
| 91 | buffer = snewn(size + 20, char); |
| 92 | ret = RegQueryValueEx(regkey, "InstallDir", NULL, |
| 93 | &type, buffer, &size); |
| 94 | if (ret == ERROR_SUCCESS && type == REG_SZ) { |
| 95 | strcat(buffer, "\\bin\\gssapi32.dll"); |
| 96 | module = LoadLibrary(buffer); |
| 97 | } |
| 98 | sfree(buffer); |
| 99 | } |
| 100 | RegCloseKey(regkey); |
| 101 | } |
| 102 | if (module) { |
| 103 | struct ssh_gss_library *lib = |
| 104 | &list->libraries[list->nlibraries++]; |
| 105 | |
| 106 | lib->id = 0; |
| 107 | lib->gsslogmsg = "Using GSSAPI from GSSAPI32.DLL"; |
| 108 | lib->handle = (void *)module; |
| 109 | |
| 110 | #define BIND_GSS_FN(name) \ |
| 111 | lib->u.gssapi.name = (t_gss_##name) GetProcAddress(module, "gss_" #name) |
| 112 | |
| 113 | BIND_GSS_FN(delete_sec_context); |
| 114 | BIND_GSS_FN(display_status); |
| 115 | BIND_GSS_FN(get_mic); |
| 116 | BIND_GSS_FN(import_name); |
| 117 | BIND_GSS_FN(init_sec_context); |
| 118 | BIND_GSS_FN(release_buffer); |
| 119 | BIND_GSS_FN(release_cred); |
| 120 | BIND_GSS_FN(release_name); |
| 121 | |
| 122 | #undef BIND_GSS_FN |
| 123 | |
| 124 | ssh_gssapi_bind_fns(lib); |
| 125 | } |
| 126 | |
| 127 | /* Microsoft SSPI Implementation */ |
| 128 | module = load_system32_dll("secur32.dll"); |
| 129 | if (module) { |
| 130 | struct ssh_gss_library *lib = |
| 131 | &list->libraries[list->nlibraries++]; |
| 132 | |
| 133 | lib->id = 1; |
| 134 | lib->gsslogmsg = "Using SSPI from SECUR32.DLL"; |
| 135 | lib->handle = (void *)module; |
| 136 | |
| 137 | GET_WINDOWS_FUNCTION(module, AcquireCredentialsHandleA); |
| 138 | GET_WINDOWS_FUNCTION(module, InitializeSecurityContextA); |
| 139 | GET_WINDOWS_FUNCTION(module, FreeContextBuffer); |
| 140 | GET_WINDOWS_FUNCTION(module, FreeCredentialsHandle); |
| 141 | GET_WINDOWS_FUNCTION(module, DeleteSecurityContext); |
| 142 | GET_WINDOWS_FUNCTION(module, QueryContextAttributesA); |
| 143 | GET_WINDOWS_FUNCTION(module, MakeSignature); |
| 144 | |
| 145 | ssh_sspi_bind_fns(lib); |
| 146 | } |
| 147 | |
| 148 | /* |
| 149 | * Custom GSSAPI DLL. |
| 150 | */ |
| 151 | module = NULL; |
| 152 | path = conf_get_filename(conf, CONF_ssh_gss_custom)->path; |
| 153 | if (*path) { |
| 154 | module = LoadLibrary(path); |
| 155 | } |
| 156 | if (module) { |
| 157 | struct ssh_gss_library *lib = |
| 158 | &list->libraries[list->nlibraries++]; |
| 159 | |
| 160 | lib->id = 2; |
| 161 | lib->gsslogmsg = dupprintf("Using GSSAPI from user-specified" |
| 162 | " library '%s'", path); |
| 163 | lib->handle = (void *)module; |
| 164 | |
| 165 | #define BIND_GSS_FN(name) \ |
| 166 | lib->u.gssapi.name = (t_gss_##name) GetProcAddress(module, "gss_" #name) |
| 167 | |
| 168 | BIND_GSS_FN(delete_sec_context); |
| 169 | BIND_GSS_FN(display_status); |
| 170 | BIND_GSS_FN(get_mic); |
| 171 | BIND_GSS_FN(import_name); |
| 172 | BIND_GSS_FN(init_sec_context); |
| 173 | BIND_GSS_FN(release_buffer); |
| 174 | BIND_GSS_FN(release_cred); |
| 175 | BIND_GSS_FN(release_name); |
| 176 | |
| 177 | #undef BIND_GSS_FN |
| 178 | |
| 179 | ssh_gssapi_bind_fns(lib); |
| 180 | } |
| 181 | |
| 182 | |
| 183 | return list; |
| 184 | } |
| 185 | |
| 186 | void ssh_gss_cleanup(struct ssh_gss_liblist *list) |
| 187 | { |
| 188 | int i; |
| 189 | |
| 190 | /* |
| 191 | * LoadLibrary and FreeLibrary are defined to employ reference |
| 192 | * counting in the case where the same library is repeatedly |
| 193 | * loaded, so even in a multiple-sessions-per-process context |
| 194 | * (not that we currently expect ever to have such a thing on |
| 195 | * Windows) it's safe to naively FreeLibrary everything here |
| 196 | * without worrying about destroying it under the feet of |
| 197 | * another SSH instance still using it. |
| 198 | */ |
| 199 | for (i = 0; i < list->nlibraries; i++) { |
| 200 | FreeLibrary((HMODULE)list->libraries[i].handle); |
| 201 | if (list->libraries[i].id == 2) { |
| 202 | /* The 'custom' id involves a dynamically allocated message. |
| 203 | * Note that we must cast away the 'const' to free it. */ |
| 204 | sfree((char *)list->libraries[i].gsslogmsg); |
| 205 | } |
| 206 | } |
| 207 | sfree(list->libraries); |
| 208 | sfree(list); |
| 209 | } |
| 210 | |
| 211 | static Ssh_gss_stat ssh_sspi_indicate_mech(struct ssh_gss_library *lib, |
| 212 | Ssh_gss_buf *mech) |
| 213 | { |
| 214 | *mech = gss_mech_krb5; |
| 215 | return SSH_GSS_OK; |
| 216 | } |
| 217 | |
| 218 | |
| 219 | static Ssh_gss_stat ssh_sspi_import_name(struct ssh_gss_library *lib, |
| 220 | char *host, Ssh_gss_name *srv_name) |
| 221 | { |
| 222 | char *pStr; |
| 223 | |
| 224 | /* Check hostname */ |
| 225 | if (host == NULL) return SSH_GSS_FAILURE; |
| 226 | |
| 227 | /* copy it into form host/FQDN */ |
| 228 | pStr = dupcat("host/", host, NULL); |
| 229 | |
| 230 | *srv_name = (Ssh_gss_name) pStr; |
| 231 | |
| 232 | return SSH_GSS_OK; |
| 233 | } |
| 234 | |
| 235 | static Ssh_gss_stat ssh_sspi_acquire_cred(struct ssh_gss_library *lib, |
| 236 | Ssh_gss_ctx *ctx) |
| 237 | { |
| 238 | winSsh_gss_ctx *winctx = snew(winSsh_gss_ctx); |
| 239 | memset(winctx, 0, sizeof(winSsh_gss_ctx)); |
| 240 | |
| 241 | /* prepare our "wrapper" structure */ |
| 242 | winctx->maj_stat = winctx->min_stat = SEC_E_OK; |
| 243 | winctx->context_handle = NULL; |
| 244 | |
| 245 | /* Specifying no principal name here means use the credentials of |
| 246 | the current logged-in user */ |
| 247 | |
| 248 | winctx->maj_stat = p_AcquireCredentialsHandleA(NULL, |
| 249 | "Kerberos", |
| 250 | SECPKG_CRED_OUTBOUND, |
| 251 | NULL, |
| 252 | NULL, |
| 253 | NULL, |
| 254 | NULL, |
| 255 | &winctx->cred_handle, |
| 256 | &winctx->expiry); |
| 257 | |
| 258 | if (winctx->maj_stat != SEC_E_OK) return SSH_GSS_FAILURE; |
| 259 | |
| 260 | *ctx = (Ssh_gss_ctx) winctx; |
| 261 | return SSH_GSS_OK; |
| 262 | } |
| 263 | |
| 264 | |
| 265 | static Ssh_gss_stat ssh_sspi_init_sec_context(struct ssh_gss_library *lib, |
| 266 | Ssh_gss_ctx *ctx, |
| 267 | Ssh_gss_name srv_name, |
| 268 | int to_deleg, |
| 269 | Ssh_gss_buf *recv_tok, |
| 270 | Ssh_gss_buf *send_tok) |
| 271 | { |
| 272 | winSsh_gss_ctx *winctx = (winSsh_gss_ctx *) *ctx; |
| 273 | SecBuffer wsend_tok = {send_tok->length,SECBUFFER_TOKEN,send_tok->value}; |
| 274 | SecBuffer wrecv_tok = {recv_tok->length,SECBUFFER_TOKEN,recv_tok->value}; |
| 275 | SecBufferDesc output_desc={SECBUFFER_VERSION,1,&wsend_tok}; |
| 276 | SecBufferDesc input_desc ={SECBUFFER_VERSION,1,&wrecv_tok}; |
| 277 | unsigned long flags=ISC_REQ_MUTUAL_AUTH|ISC_REQ_REPLAY_DETECT| |
| 278 | ISC_REQ_CONFIDENTIALITY|ISC_REQ_ALLOCATE_MEMORY; |
| 279 | unsigned long ret_flags=0; |
| 280 | |
| 281 | /* check if we have to delegate ... */ |
| 282 | if (to_deleg) flags |= ISC_REQ_DELEGATE; |
| 283 | winctx->maj_stat = p_InitializeSecurityContextA(&winctx->cred_handle, |
| 284 | winctx->context_handle, |
| 285 | (char*) srv_name, |
| 286 | flags, |
| 287 | 0, /* reserved */ |
| 288 | SECURITY_NATIVE_DREP, |
| 289 | &input_desc, |
| 290 | 0, /* reserved */ |
| 291 | &winctx->context, |
| 292 | &output_desc, |
| 293 | &ret_flags, |
| 294 | &winctx->expiry); |
| 295 | |
| 296 | /* prepare for the next round */ |
| 297 | winctx->context_handle = &winctx->context; |
| 298 | send_tok->value = wsend_tok.pvBuffer; |
| 299 | send_tok->length = wsend_tok.cbBuffer; |
| 300 | |
| 301 | /* check & return our status */ |
| 302 | if (winctx->maj_stat==SEC_E_OK) return SSH_GSS_S_COMPLETE; |
| 303 | if (winctx->maj_stat==SEC_I_CONTINUE_NEEDED) return SSH_GSS_S_CONTINUE_NEEDED; |
| 304 | |
| 305 | return SSH_GSS_FAILURE; |
| 306 | } |
| 307 | |
| 308 | static Ssh_gss_stat ssh_sspi_free_tok(struct ssh_gss_library *lib, |
| 309 | Ssh_gss_buf *send_tok) |
| 310 | { |
| 311 | /* check input */ |
| 312 | if (send_tok == NULL) return SSH_GSS_FAILURE; |
| 313 | |
| 314 | /* free Windows buffer */ |
| 315 | p_FreeContextBuffer(send_tok->value); |
| 316 | SSH_GSS_CLEAR_BUF(send_tok); |
| 317 | |
| 318 | return SSH_GSS_OK; |
| 319 | } |
| 320 | |
| 321 | static Ssh_gss_stat ssh_sspi_release_cred(struct ssh_gss_library *lib, |
| 322 | Ssh_gss_ctx *ctx) |
| 323 | { |
| 324 | winSsh_gss_ctx *winctx= (winSsh_gss_ctx *) *ctx; |
| 325 | |
| 326 | /* check input */ |
| 327 | if (winctx == NULL) return SSH_GSS_FAILURE; |
| 328 | |
| 329 | /* free Windows data */ |
| 330 | p_FreeCredentialsHandle(&winctx->cred_handle); |
| 331 | p_DeleteSecurityContext(&winctx->context); |
| 332 | |
| 333 | /* delete our "wrapper" structure */ |
| 334 | sfree(winctx); |
| 335 | *ctx = (Ssh_gss_ctx) NULL; |
| 336 | |
| 337 | return SSH_GSS_OK; |
| 338 | } |
| 339 | |
| 340 | |
| 341 | static Ssh_gss_stat ssh_sspi_release_name(struct ssh_gss_library *lib, |
| 342 | Ssh_gss_name *srv_name) |
| 343 | { |
| 344 | char *pStr= (char *) *srv_name; |
| 345 | |
| 346 | if (pStr == NULL) return SSH_GSS_FAILURE; |
| 347 | sfree(pStr); |
| 348 | *srv_name = (Ssh_gss_name) NULL; |
| 349 | |
| 350 | return SSH_GSS_OK; |
| 351 | } |
| 352 | |
| 353 | static Ssh_gss_stat ssh_sspi_display_status(struct ssh_gss_library *lib, |
| 354 | Ssh_gss_ctx ctx, Ssh_gss_buf *buf) |
| 355 | { |
| 356 | winSsh_gss_ctx *winctx = (winSsh_gss_ctx *) ctx; |
| 357 | char *msg; |
| 358 | |
| 359 | if (winctx == NULL) return SSH_GSS_FAILURE; |
| 360 | |
| 361 | /* decode the error code */ |
| 362 | switch (winctx->maj_stat) { |
| 363 | case SEC_E_OK: msg="SSPI status OK"; break; |
| 364 | case SEC_E_INVALID_HANDLE: msg="The handle passed to the function" |
| 365 | " is invalid."; |
| 366 | break; |
| 367 | case SEC_E_TARGET_UNKNOWN: msg="The target was not recognized."; break; |
| 368 | case SEC_E_LOGON_DENIED: msg="The logon failed."; break; |
| 369 | case SEC_E_INTERNAL_ERROR: msg="The Local Security Authority cannot" |
| 370 | " be contacted."; |
| 371 | break; |
| 372 | case SEC_E_NO_CREDENTIALS: msg="No credentials are available in the" |
| 373 | " security package."; |
| 374 | break; |
| 375 | case SEC_E_NO_AUTHENTICATING_AUTHORITY: |
| 376 | msg="No authority could be contacted for authentication." |
| 377 | "The domain name of the authenticating party could be wrong," |
| 378 | " the domain could be unreachable, or there might have been" |
| 379 | " a trust relationship failure."; |
| 380 | break; |
| 381 | case SEC_E_INSUFFICIENT_MEMORY: |
| 382 | msg="One or more of the SecBufferDesc structures passed as" |
| 383 | " an OUT parameter has a buffer that is too small."; |
| 384 | break; |
| 385 | case SEC_E_INVALID_TOKEN: |
| 386 | msg="The error is due to a malformed input token, such as a" |
| 387 | " token corrupted in transit, a token" |
| 388 | " of incorrect size, or a token passed into the wrong" |
| 389 | " security package. Passing a token to" |
| 390 | " the wrong package can happen if client and server did not" |
| 391 | " negotiate the proper security package."; |
| 392 | break; |
| 393 | default: |
| 394 | msg = "Internal SSPI error"; |
| 395 | break; |
| 396 | } |
| 397 | |
| 398 | buf->value = dupstr(msg); |
| 399 | buf->length = strlen(buf->value); |
| 400 | |
| 401 | return SSH_GSS_OK; |
| 402 | } |
| 403 | |
| 404 | static Ssh_gss_stat ssh_sspi_get_mic(struct ssh_gss_library *lib, |
| 405 | Ssh_gss_ctx ctx, Ssh_gss_buf *buf, |
| 406 | Ssh_gss_buf *hash) |
| 407 | { |
| 408 | winSsh_gss_ctx *winctx= (winSsh_gss_ctx *) ctx; |
| 409 | SecPkgContext_Sizes ContextSizes; |
| 410 | SecBufferDesc InputBufferDescriptor; |
| 411 | SecBuffer InputSecurityToken[2]; |
| 412 | |
| 413 | if (winctx == NULL) return SSH_GSS_FAILURE; |
| 414 | |
| 415 | winctx->maj_stat = 0; |
| 416 | |
| 417 | memset(&ContextSizes, 0, sizeof(ContextSizes)); |
| 418 | |
| 419 | winctx->maj_stat = p_QueryContextAttributesA(&winctx->context, |
| 420 | SECPKG_ATTR_SIZES, |
| 421 | &ContextSizes); |
| 422 | |
| 423 | if (winctx->maj_stat != SEC_E_OK || |
| 424 | ContextSizes.cbMaxSignature == 0) |
| 425 | return winctx->maj_stat; |
| 426 | |
| 427 | InputBufferDescriptor.cBuffers = 2; |
| 428 | InputBufferDescriptor.pBuffers = InputSecurityToken; |
| 429 | InputBufferDescriptor.ulVersion = SECBUFFER_VERSION; |
| 430 | InputSecurityToken[0].BufferType = SECBUFFER_DATA; |
| 431 | InputSecurityToken[0].cbBuffer = buf->length; |
| 432 | InputSecurityToken[0].pvBuffer = buf->value; |
| 433 | InputSecurityToken[1].BufferType = SECBUFFER_TOKEN; |
| 434 | InputSecurityToken[1].cbBuffer = ContextSizes.cbMaxSignature; |
| 435 | InputSecurityToken[1].pvBuffer = snewn(ContextSizes.cbMaxSignature, char); |
| 436 | |
| 437 | winctx->maj_stat = p_MakeSignature(&winctx->context, |
| 438 | 0, |
| 439 | &InputBufferDescriptor, |
| 440 | 0); |
| 441 | |
| 442 | if (winctx->maj_stat == SEC_E_OK) { |
| 443 | hash->length = InputSecurityToken[1].cbBuffer; |
| 444 | hash->value = InputSecurityToken[1].pvBuffer; |
| 445 | } |
| 446 | |
| 447 | return winctx->maj_stat; |
| 448 | } |
| 449 | |
| 450 | static Ssh_gss_stat ssh_sspi_free_mic(struct ssh_gss_library *lib, |
| 451 | Ssh_gss_buf *hash) |
| 452 | { |
| 453 | sfree(hash->value); |
| 454 | return SSH_GSS_OK; |
| 455 | } |
| 456 | |
| 457 | static void ssh_sspi_bind_fns(struct ssh_gss_library *lib) |
| 458 | { |
| 459 | lib->indicate_mech = ssh_sspi_indicate_mech; |
| 460 | lib->import_name = ssh_sspi_import_name; |
| 461 | lib->release_name = ssh_sspi_release_name; |
| 462 | lib->init_sec_context = ssh_sspi_init_sec_context; |
| 463 | lib->free_tok = ssh_sspi_free_tok; |
| 464 | lib->acquire_cred = ssh_sspi_acquire_cred; |
| 465 | lib->release_cred = ssh_sspi_release_cred; |
| 466 | lib->get_mic = ssh_sspi_get_mic; |
| 467 | lib->free_mic = ssh_sspi_free_mic; |
| 468 | lib->display_status = ssh_sspi_display_status; |
| 469 | } |
| 470 | |
| 471 | #else |
| 472 | |
| 473 | /* Dummy function so this source file defines something if NO_GSSAPI |
| 474 | is defined. */ |
| 475 | |
| 476 | void ssh_gss_init(void) |
| 477 | { |
| 478 | } |
| 479 | |
| 480 | #endif |