eng_dyn.c revision 109998
1/* crypto/engine/eng_dyn.c */ 2/* Written by Geoff Thorpe (geoff@geoffthorpe.net) for the OpenSSL 3 * project 2001. 4 */ 5/* ==================================================================== 6 * Copyright (c) 1999-2001 The OpenSSL Project. All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 12 * 1. Redistributions of source code must retain the above copyright 13 * notice, this list of conditions and the following disclaimer. 14 * 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in 17 * the documentation and/or other materials provided with the 18 * distribution. 19 * 20 * 3. All advertising materials mentioning features or use of this 21 * software must display the following acknowledgment: 22 * "This product includes software developed by the OpenSSL Project 23 * for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)" 24 * 25 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to 26 * endorse or promote products derived from this software without 27 * prior written permission. For written permission, please contact 28 * licensing@OpenSSL.org. 29 * 30 * 5. Products derived from this software may not be called "OpenSSL" 31 * nor may "OpenSSL" appear in their names without prior written 32 * permission of the OpenSSL Project. 33 * 34 * 6. Redistributions of any form whatsoever must retain the following 35 * acknowledgment: 36 * "This product includes software developed by the OpenSSL Project 37 * for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)" 38 * 39 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY 40 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 41 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 42 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR 43 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 44 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 45 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 46 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 47 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, 48 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 49 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED 50 * OF THE POSSIBILITY OF SUCH DAMAGE. 51 * ==================================================================== 52 * 53 * This product includes cryptographic software written by Eric Young 54 * (eay@cryptsoft.com). This product includes software written by Tim 55 * Hudson (tjh@cryptsoft.com). 56 * 57 */ 58 59 60#include <stdio.h> 61#include <openssl/crypto.h> 62#include "cryptlib.h" 63#include "eng_int.h" 64#include <openssl/engine.h> 65#include <openssl/dso.h> 66 67/* Shared libraries implementing ENGINEs for use by the "dynamic" ENGINE loader 68 * should implement the hook-up functions with the following prototypes. */ 69 70/* Our ENGINE handlers */ 71static int dynamic_init(ENGINE *e); 72static int dynamic_finish(ENGINE *e); 73static int dynamic_ctrl(ENGINE *e, int cmd, long i, void *p, void (*f)()); 74/* Predeclare our context type */ 75typedef struct st_dynamic_data_ctx dynamic_data_ctx; 76/* The implementation for the important control command */ 77static int dynamic_load(ENGINE *e, dynamic_data_ctx *ctx); 78 79#define DYNAMIC_CMD_SO_PATH ENGINE_CMD_BASE 80#define DYNAMIC_CMD_NO_VCHECK (ENGINE_CMD_BASE + 1) 81#define DYNAMIC_CMD_ID (ENGINE_CMD_BASE + 2) 82#define DYNAMIC_CMD_LIST_ADD (ENGINE_CMD_BASE + 3) 83#define DYNAMIC_CMD_LOAD (ENGINE_CMD_BASE + 4) 84 85/* The constants used when creating the ENGINE */ 86static const char *engine_dynamic_id = "dynamic"; 87static const char *engine_dynamic_name = "Dynamic engine loading support"; 88static const ENGINE_CMD_DEFN dynamic_cmd_defns[] = { 89 {DYNAMIC_CMD_SO_PATH, 90 "SO_PATH", 91 "Specifies the path to the new ENGINE shared library", 92 ENGINE_CMD_FLAG_STRING}, 93 {DYNAMIC_CMD_NO_VCHECK, 94 "NO_VCHECK", 95 "Specifies to continue even if version checking fails (boolean)", 96 ENGINE_CMD_FLAG_NUMERIC}, 97 {DYNAMIC_CMD_ID, 98 "ID", 99 "Specifies an ENGINE id name for loading", 100 ENGINE_CMD_FLAG_STRING}, 101 {DYNAMIC_CMD_LIST_ADD, 102 "LIST_ADD", 103 "Whether to add a loaded ENGINE to the internal list (0=no,1=yes,2=mandatory)", 104 ENGINE_CMD_FLAG_NUMERIC}, 105 {DYNAMIC_CMD_LOAD, 106 "LOAD", 107 "Load up the ENGINE specified by other settings", 108 ENGINE_CMD_FLAG_NO_INPUT}, 109 {0, NULL, NULL, 0} 110 }; 111static const ENGINE_CMD_DEFN dynamic_cmd_defns_empty[] = { 112 {0, NULL, NULL, 0} 113 }; 114 115/* Loading code stores state inside the ENGINE structure via the "ex_data" 116 * element. We load all our state into a single structure and use that as a 117 * single context in the "ex_data" stack. */ 118struct st_dynamic_data_ctx 119 { 120 /* The DSO object we load that supplies the ENGINE code */ 121 DSO *dynamic_dso; 122 /* The function pointer to the version checking shared library function */ 123 dynamic_v_check_fn v_check; 124 /* The function pointer to the engine-binding shared library function */ 125 dynamic_bind_engine bind_engine; 126 /* The default name/path for loading the shared library */ 127 const char *DYNAMIC_LIBNAME; 128 /* Whether to continue loading on a version check failure */ 129 int no_vcheck; 130 /* If non-NULL, stipulates the 'id' of the ENGINE to be loaded */ 131 const char *engine_id; 132 /* If non-zero, a successfully loaded ENGINE should be added to the internal 133 * ENGINE list. If 2, the add must succeed or the entire load should fail. */ 134 int list_add_value; 135 /* The symbol name for the version checking function */ 136 const char *DYNAMIC_F1; 137 /* The symbol name for the "initialise ENGINE structure" function */ 138 const char *DYNAMIC_F2; 139 }; 140 141/* This is the "ex_data" index we obtain and reserve for use with our context 142 * structure. */ 143static int dynamic_ex_data_idx = -1; 144 145/* Because our ex_data element may or may not get allocated depending on whether 146 * a "first-use" occurs before the ENGINE is freed, we have a memory leak 147 * problem to solve. We can't declare a "new" handler for the ex_data as we 148 * don't want a dynamic_data_ctx in *all* ENGINE structures of all types (this 149 * is a bug in the design of CRYPTO_EX_DATA). As such, we just declare a "free" 150 * handler and that will get called if an ENGINE is being destroyed and there 151 * was an ex_data element corresponding to our context type. */ 152static void dynamic_data_ctx_free_func(void *parent, void *ptr, 153 CRYPTO_EX_DATA *ad, int idx, long argl, void *argp) 154 { 155 if(ptr) 156 { 157 dynamic_data_ctx *ctx = (dynamic_data_ctx *)ptr; 158 if(ctx->dynamic_dso) 159 DSO_free(ctx->dynamic_dso); 160 if(ctx->DYNAMIC_LIBNAME) 161 OPENSSL_free((void*)ctx->DYNAMIC_LIBNAME); 162 if(ctx->engine_id) 163 OPENSSL_free((void*)ctx->engine_id); 164 OPENSSL_free(ctx); 165 } 166 } 167 168/* Construct the per-ENGINE context. We create it blindly and then use a lock to 169 * check for a race - if so, all but one of the threads "racing" will have 170 * wasted their time. The alternative involves creating everything inside the 171 * lock which is far worse. */ 172static int dynamic_set_data_ctx(ENGINE *e, dynamic_data_ctx **ctx) 173 { 174 dynamic_data_ctx *c; 175 c = OPENSSL_malloc(sizeof(dynamic_data_ctx)); 176 if(!c) 177 { 178 ENGINEerr(ENGINE_F_SET_DATA_CTX,ERR_R_MALLOC_FAILURE); 179 return 0; 180 } 181 memset(c, 0, sizeof(dynamic_data_ctx)); 182 c->dynamic_dso = NULL; 183 c->v_check = NULL; 184 c->bind_engine = NULL; 185 c->DYNAMIC_LIBNAME = NULL; 186 c->no_vcheck = 0; 187 c->engine_id = NULL; 188 c->list_add_value = 0; 189 c->DYNAMIC_F1 = "v_check"; 190 c->DYNAMIC_F2 = "bind_engine"; 191 CRYPTO_w_lock(CRYPTO_LOCK_ENGINE); 192 if((*ctx = (dynamic_data_ctx *)ENGINE_get_ex_data(e, 193 dynamic_ex_data_idx)) == NULL) 194 { 195 /* Good, we're the first */ 196 ENGINE_set_ex_data(e, dynamic_ex_data_idx, c); 197 *ctx = c; 198 c = NULL; 199 } 200 CRYPTO_w_unlock(CRYPTO_LOCK_ENGINE); 201 /* If we lost the race to set the context, c is non-NULL and *ctx is the 202 * context of the thread that won. */ 203 if(c) 204 OPENSSL_free(c); 205 return 1; 206 } 207 208/* This function retrieves the context structure from an ENGINE's "ex_data", or 209 * if it doesn't exist yet, sets it up. */ 210static dynamic_data_ctx *dynamic_get_data_ctx(ENGINE *e) 211 { 212 dynamic_data_ctx *ctx; 213 if(dynamic_ex_data_idx < 0) 214 { 215 /* Create and register the ENGINE ex_data, and associate our 216 * "free" function with it to ensure any allocated contexts get 217 * freed when an ENGINE goes underground. */ 218 int new_idx = ENGINE_get_ex_new_index(0, NULL, NULL, NULL, 219 dynamic_data_ctx_free_func); 220 if(new_idx == -1) 221 { 222 ENGINEerr(ENGINE_F_DYNAMIC_GET_DATA_CTX,ENGINE_R_NO_INDEX); 223 return NULL; 224 } 225 CRYPTO_w_lock(CRYPTO_LOCK_ENGINE); 226 /* Avoid a race by checking again inside this lock */ 227 if(dynamic_ex_data_idx < 0) 228 { 229 /* Good, someone didn't beat us to it */ 230 dynamic_ex_data_idx = new_idx; 231 new_idx = -1; 232 } 233 CRYPTO_w_unlock(CRYPTO_LOCK_ENGINE); 234 /* In theory we could "give back" the index here if 235 * (new_idx>-1), but it's not possible and wouldn't gain us much 236 * if it were. */ 237 } 238 ctx = (dynamic_data_ctx *)ENGINE_get_ex_data(e, dynamic_ex_data_idx); 239 /* Check if the context needs to be created */ 240 if((ctx == NULL) && !dynamic_set_data_ctx(e, &ctx)) 241 /* "set_data" will set errors if necessary */ 242 return NULL; 243 return ctx; 244 } 245 246static ENGINE *engine_dynamic(void) 247 { 248 ENGINE *ret = ENGINE_new(); 249 if(!ret) 250 return NULL; 251 if(!ENGINE_set_id(ret, engine_dynamic_id) || 252 !ENGINE_set_name(ret, engine_dynamic_name) || 253 !ENGINE_set_init_function(ret, dynamic_init) || 254 !ENGINE_set_finish_function(ret, dynamic_finish) || 255 !ENGINE_set_ctrl_function(ret, dynamic_ctrl) || 256 !ENGINE_set_flags(ret, ENGINE_FLAGS_BY_ID_COPY) || 257 !ENGINE_set_cmd_defns(ret, dynamic_cmd_defns)) 258 { 259 ENGINE_free(ret); 260 return NULL; 261 } 262 return ret; 263 } 264 265void ENGINE_load_dynamic(void) 266 { 267 ENGINE *toadd = engine_dynamic(); 268 if(!toadd) return; 269 ENGINE_add(toadd); 270 /* If the "add" worked, it gets a structural reference. So either way, 271 * we release our just-created reference. */ 272 ENGINE_free(toadd); 273 /* If the "add" didn't work, it was probably a conflict because it was 274 * already added (eg. someone calling ENGINE_load_blah then calling 275 * ENGINE_load_builtin_engines() perhaps). */ 276 ERR_clear_error(); 277 } 278 279static int dynamic_init(ENGINE *e) 280 { 281 /* We always return failure - the "dyanamic" engine itself can't be used 282 * for anything. */ 283 return 0; 284 } 285 286static int dynamic_finish(ENGINE *e) 287 { 288 /* This should never be called on account of "dynamic_init" always 289 * failing. */ 290 return 0; 291 } 292 293static int dynamic_ctrl(ENGINE *e, int cmd, long i, void *p, void (*f)()) 294 { 295 dynamic_data_ctx *ctx = dynamic_get_data_ctx(e); 296 int initialised; 297 298 if(!ctx) 299 { 300 ENGINEerr(ENGINE_F_DYNAMIC_CTRL,ENGINE_R_NOT_LOADED); 301 return 0; 302 } 303 initialised = ((ctx->dynamic_dso == NULL) ? 0 : 1); 304 /* All our control commands require the ENGINE to be uninitialised */ 305 if(initialised) 306 { 307 ENGINEerr(ENGINE_F_DYNAMIC_CTRL, 308 ENGINE_R_ALREADY_LOADED); 309 return 0; 310 } 311 switch(cmd) 312 { 313 case DYNAMIC_CMD_SO_PATH: 314 /* a NULL 'p' or a string of zero-length is the same thing */ 315 if(p && (strlen((const char *)p) < 1)) 316 p = NULL; 317 if(ctx->DYNAMIC_LIBNAME) 318 OPENSSL_free((void*)ctx->DYNAMIC_LIBNAME); 319 if(p) 320 ctx->DYNAMIC_LIBNAME = BUF_strdup(p); 321 else 322 ctx->DYNAMIC_LIBNAME = NULL; 323 return (ctx->DYNAMIC_LIBNAME ? 1 : 0); 324 case DYNAMIC_CMD_NO_VCHECK: 325 ctx->no_vcheck = ((i == 0) ? 0 : 1); 326 return 1; 327 case DYNAMIC_CMD_ID: 328 /* a NULL 'p' or a string of zero-length is the same thing */ 329 if(p && (strlen((const char *)p) < 1)) 330 p = NULL; 331 if(ctx->engine_id) 332 OPENSSL_free((void*)ctx->engine_id); 333 if(p) 334 ctx->engine_id = BUF_strdup(p); 335 else 336 ctx->engine_id = NULL; 337 return (ctx->engine_id ? 1 : 0); 338 case DYNAMIC_CMD_LIST_ADD: 339 if((i < 0) || (i > 2)) 340 { 341 ENGINEerr(ENGINE_F_DYNAMIC_CTRL, 342 ENGINE_R_INVALID_ARGUMENT); 343 return 0; 344 } 345 ctx->list_add_value = (int)i; 346 return 1; 347 case DYNAMIC_CMD_LOAD: 348 return dynamic_load(e, ctx); 349 default: 350 break; 351 } 352 ENGINEerr(ENGINE_F_DYNAMIC_CTRL,ENGINE_R_CTRL_COMMAND_NOT_IMPLEMENTED); 353 return 0; 354 } 355 356static int dynamic_load(ENGINE *e, dynamic_data_ctx *ctx) 357 { 358 ENGINE cpy; 359 dynamic_fns fns; 360 361 if(!ctx->DYNAMIC_LIBNAME || ((ctx->dynamic_dso = DSO_load(NULL, 362 ctx->DYNAMIC_LIBNAME, NULL, 0)) == NULL)) 363 { 364 ENGINEerr(ENGINE_F_DYNAMIC_LOAD, 365 ENGINE_R_DSO_NOT_FOUND); 366 return 0; 367 } 368 /* We have to find a bind function otherwise it'll always end badly */ 369 if(!(ctx->bind_engine = (dynamic_bind_engine)DSO_bind_func( 370 ctx->dynamic_dso, ctx->DYNAMIC_F2))) 371 { 372 ctx->bind_engine = NULL; 373 DSO_free(ctx->dynamic_dso); 374 ctx->dynamic_dso = NULL; 375 ENGINEerr(ENGINE_F_DYNAMIC_LOAD, 376 ENGINE_R_DSO_FAILURE); 377 return 0; 378 } 379 /* Do we perform version checking? */ 380 if(!ctx->no_vcheck) 381 { 382 unsigned long vcheck_res = 0; 383 /* Now we try to find a version checking function and decide how 384 * to cope with failure if/when it fails. */ 385 ctx->v_check = (dynamic_v_check_fn)DSO_bind_func( 386 ctx->dynamic_dso, ctx->DYNAMIC_F1); 387 if(ctx->v_check) 388 vcheck_res = ctx->v_check(OSSL_DYNAMIC_VERSION); 389 /* We fail if the version checker veto'd the load *or* if it is 390 * deferring to us (by returning its version) and we think it is 391 * too old. */ 392 if(vcheck_res < OSSL_DYNAMIC_OLDEST) 393 { 394 /* Fail */ 395 ctx->bind_engine = NULL; 396 ctx->v_check = NULL; 397 DSO_free(ctx->dynamic_dso); 398 ctx->dynamic_dso = NULL; 399 ENGINEerr(ENGINE_F_DYNAMIC_LOAD, 400 ENGINE_R_VERSION_INCOMPATIBILITY); 401 return 0; 402 } 403 } 404 /* First binary copy the ENGINE structure so that we can roll back if 405 * the hand-over fails */ 406 memcpy(&cpy, e, sizeof(ENGINE)); 407 /* Provide the ERR, "ex_data", memory, and locking callbacks so the 408 * loaded library uses our state rather than its own. FIXME: As noted in 409 * engine.h, much of this would be simplified if each area of code 410 * provided its own "summary" structure of all related callbacks. It 411 * would also increase opaqueness. */ 412 fns.err_fns = ERR_get_implementation(); 413 fns.ex_data_fns = CRYPTO_get_ex_data_implementation(); 414 CRYPTO_get_mem_functions(&fns.mem_fns.malloc_cb, 415 &fns.mem_fns.realloc_cb, 416 &fns.mem_fns.free_cb); 417 fns.lock_fns.lock_locking_cb = CRYPTO_get_locking_callback(); 418 fns.lock_fns.lock_add_lock_cb = CRYPTO_get_add_lock_callback(); 419 fns.lock_fns.dynlock_create_cb = CRYPTO_get_dynlock_create_callback(); 420 fns.lock_fns.dynlock_lock_cb = CRYPTO_get_dynlock_lock_callback(); 421 fns.lock_fns.dynlock_destroy_cb = CRYPTO_get_dynlock_destroy_callback(); 422 /* Now that we've loaded the dynamic engine, make sure no "dynamic" 423 * ENGINE elements will show through. */ 424 engine_set_all_null(e); 425 426 /* Try to bind the ENGINE onto our own ENGINE structure */ 427 if(!ctx->bind_engine(e, ctx->engine_id, &fns)) 428 { 429 ctx->bind_engine = NULL; 430 ctx->v_check = NULL; 431 DSO_free(ctx->dynamic_dso); 432 ctx->dynamic_dso = NULL; 433 ENGINEerr(ENGINE_F_DYNAMIC_LOAD,ENGINE_R_INIT_FAILED); 434 /* Copy the original ENGINE structure back */ 435 memcpy(e, &cpy, sizeof(ENGINE)); 436 return 0; 437 } 438 /* Do we try to add this ENGINE to the internal list too? */ 439 if(ctx->list_add_value > 0) 440 { 441 if(!ENGINE_add(e)) 442 { 443 /* Do we tolerate this or fail? */ 444 if(ctx->list_add_value > 1) 445 { 446 /* Fail - NB: By this time, it's too late to 447 * rollback, and trying to do so allows the 448 * bind_engine() code to have created leaks. We 449 * just have to fail where we are, after the 450 * ENGINE has changed. */ 451 ENGINEerr(ENGINE_F_DYNAMIC_LOAD, 452 ENGINE_R_CONFLICTING_ENGINE_ID); 453 return 0; 454 } 455 /* Tolerate */ 456 ERR_clear_error(); 457 } 458 } 459 return 1; 460 } 461