/* crypto/engine/eng_dyn.c */ /* Written by Geoff Thorpe (geoff@geoffthorpe.net) for the OpenSSL * project 2001. */ /* ==================================================================== * Copyright (c) 1999-2001 The OpenSSL Project. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in * the documentation and/or other materials provided with the * distribution. * * 3. All advertising materials mentioning features or use of this * software must display the following acknowledgment: * "This product includes software developed by the OpenSSL Project * for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)" * * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to * endorse or promote products derived from this software without * prior written permission. For written permission, please contact * licensing@OpenSSL.org. * * 5. Products derived from this software may not be called "OpenSSL" * nor may "OpenSSL" appear in their names without prior written * permission of the OpenSSL Project. * * 6. Redistributions of any form whatsoever must retain the following * acknowledgment: * "This product includes software developed by the OpenSSL Project * for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)" * * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED * OF THE POSSIBILITY OF SUCH DAMAGE. * ==================================================================== * * This product includes cryptographic software written by Eric Young * (eay@cryptsoft.com). This product includes software written by Tim * Hudson (tjh@cryptsoft.com). * */ #include <stdio.h> #include <openssl/crypto.h> #include "cryptlib.h" #include "eng_int.h" #include <openssl/engine.h> #include <openssl/dso.h> /* Shared libraries implementing ENGINEs for use by the "dynamic" ENGINE loader * should implement the hook-up functions with the following prototypes. */ /* Our ENGINE handlers */ static int dynamic_init(ENGINE *e); static int dynamic_finish(ENGINE *e); static int dynamic_ctrl(ENGINE *e, int cmd, long i, void *p, void (*f)()); /* Predeclare our context type */ typedef struct st_dynamic_data_ctx dynamic_data_ctx; /* The implementation for the important control command */ static int dynamic_load(ENGINE *e, dynamic_data_ctx *ctx); #define DYNAMIC_CMD_SO_PATH ENGINE_CMD_BASE #define DYNAMIC_CMD_NO_VCHECK (ENGINE_CMD_BASE + 1) #define DYNAMIC_CMD_ID (ENGINE_CMD_BASE + 2) #define DYNAMIC_CMD_LIST_ADD (ENGINE_CMD_BASE + 3) #define DYNAMIC_CMD_LOAD (ENGINE_CMD_BASE + 4) /* The constants used when creating the ENGINE */ static const char *engine_dynamic_id = "dynamic"; static const char *engine_dynamic_name = "Dynamic engine loading support"; static const ENGINE_CMD_DEFN dynamic_cmd_defns[] = { {DYNAMIC_CMD_SO_PATH, "SO_PATH", "Specifies the path to the new ENGINE shared library", ENGINE_CMD_FLAG_STRING}, {DYNAMIC_CMD_NO_VCHECK, "NO_VCHECK", "Specifies to continue even if version checking fails (boolean)", ENGINE_CMD_FLAG_NUMERIC}, {DYNAMIC_CMD_ID, "ID", "Specifies an ENGINE id name for loading", ENGINE_CMD_FLAG_STRING}, {DYNAMIC_CMD_LIST_ADD, "LIST_ADD", "Whether to add a loaded ENGINE to the internal list (0=no,1=yes,2=mandatory)", ENGINE_CMD_FLAG_NUMERIC}, {DYNAMIC_CMD_LOAD, "LOAD", "Load up the ENGINE specified by other settings", ENGINE_CMD_FLAG_NO_INPUT}, {0, NULL, NULL, 0} }; static const ENGINE_CMD_DEFN dynamic_cmd_defns_empty[] = { {0, NULL, NULL, 0} }; /* Loading code stores state inside the ENGINE structure via the "ex_data" * element. We load all our state into a single structure and use that as a * single context in the "ex_data" stack. */ struct st_dynamic_data_ctx { /* The DSO object we load that supplies the ENGINE code */ DSO *dynamic_dso; /* The function pointer to the version checking shared library function */ dynamic_v_check_fn v_check; /* The function pointer to the engine-binding shared library function */ dynamic_bind_engine bind_engine; /* The default name/path for loading the shared library */ const char *DYNAMIC_LIBNAME; /* Whether to continue loading on a version check failure */ int no_vcheck; /* If non-NULL, stipulates the 'id' of the ENGINE to be loaded */ const char *engine_id; /* If non-zero, a successfully loaded ENGINE should be added to the internal * ENGINE list. If 2, the add must succeed or the entire load should fail. */ int list_add_value; /* The symbol name for the version checking function */ const char *DYNAMIC_F1; /* The symbol name for the "initialise ENGINE structure" function */ const char *DYNAMIC_F2; }; /* This is the "ex_data" index we obtain and reserve for use with our context * structure. */ static int dynamic_ex_data_idx = -1; /* Because our ex_data element may or may not get allocated depending on whether * a "first-use" occurs before the ENGINE is freed, we have a memory leak * problem to solve. We can't declare a "new" handler for the ex_data as we * don't want a dynamic_data_ctx in *all* ENGINE structures of all types (this * is a bug in the design of CRYPTO_EX_DATA). As such, we just declare a "free" * handler and that will get called if an ENGINE is being destroyed and there * was an ex_data element corresponding to our context type. */ static void dynamic_data_ctx_free_func(void *parent, void *ptr, CRYPTO_EX_DATA *ad, int idx, long argl, void *argp) { if(ptr) { dynamic_data_ctx *ctx = (dynamic_data_ctx *)ptr; if(ctx->dynamic_dso) DSO_free(ctx->dynamic_dso); if(ctx->DYNAMIC_LIBNAME) OPENSSL_free((void*)ctx->DYNAMIC_LIBNAME); if(ctx->engine_id) OPENSSL_free((void*)ctx->engine_id); OPENSSL_free(ctx); } } /* Construct the per-ENGINE context. We create it blindly and then use a lock to * check for a race - if so, all but one of the threads "racing" will have * wasted their time. The alternative involves creating everything inside the * lock which is far worse. */ static int dynamic_set_data_ctx(ENGINE *e, dynamic_data_ctx **ctx) { dynamic_data_ctx *c; c = OPENSSL_malloc(sizeof(dynamic_data_ctx)); if(!c) { ENGINEerr(ENGINE_F_SET_DATA_CTX,ERR_R_MALLOC_FAILURE); return 0; } memset(c, 0, sizeof(dynamic_data_ctx)); c->dynamic_dso = NULL; c->v_check = NULL; c->bind_engine = NULL; c->DYNAMIC_LIBNAME = NULL; c->no_vcheck = 0; c->engine_id = NULL; c->list_add_value = 0; c->DYNAMIC_F1 = "v_check"; c->DYNAMIC_F2 = "bind_engine"; CRYPTO_w_lock(CRYPTO_LOCK_ENGINE); if((*ctx = (dynamic_data_ctx *)ENGINE_get_ex_data(e, dynamic_ex_data_idx)) == NULL) { /* Good, we're the first */ ENGINE_set_ex_data(e, dynamic_ex_data_idx, c); *ctx = c; c = NULL; } CRYPTO_w_unlock(CRYPTO_LOCK_ENGINE); /* If we lost the race to set the context, c is non-NULL and *ctx is the * context of the thread that won. */ if(c) OPENSSL_free(c); return 1; } /* This function retrieves the context structure from an ENGINE's "ex_data", or * if it doesn't exist yet, sets it up. */ static dynamic_data_ctx *dynamic_get_data_ctx(ENGINE *e) { dynamic_data_ctx *ctx; if(dynamic_ex_data_idx < 0) { /* Create and register the ENGINE ex_data, and associate our * "free" function with it to ensure any allocated contexts get * freed when an ENGINE goes underground. */ int new_idx = ENGINE_get_ex_new_index(0, NULL, NULL, NULL, dynamic_data_ctx_free_func); if(new_idx == -1) { ENGINEerr(ENGINE_F_DYNAMIC_GET_DATA_CTX,ENGINE_R_NO_INDEX); return NULL; } CRYPTO_w_lock(CRYPTO_LOCK_ENGINE); /* Avoid a race by checking again inside this lock */ if(dynamic_ex_data_idx < 0) { /* Good, someone didn't beat us to it */ dynamic_ex_data_idx = new_idx; new_idx = -1; } CRYPTO_w_unlock(CRYPTO_LOCK_ENGINE); /* In theory we could "give back" the index here if * (new_idx>-1), but it's not possible and wouldn't gain us much * if it were. */ } ctx = (dynamic_data_ctx *)ENGINE_get_ex_data(e, dynamic_ex_data_idx); /* Check if the context needs to be created */ if((ctx == NULL) && !dynamic_set_data_ctx(e, &ctx)) /* "set_data" will set errors if necessary */ return NULL; return ctx; } static ENGINE *engine_dynamic(void) { ENGINE *ret = ENGINE_new(); if(!ret) return NULL; if(!ENGINE_set_id(ret, engine_dynamic_id) || !ENGINE_set_name(ret, engine_dynamic_name) || !ENGINE_set_init_function(ret, dynamic_init) || !ENGINE_set_finish_function(ret, dynamic_finish) || !ENGINE_set_ctrl_function(ret, dynamic_ctrl) || !ENGINE_set_flags(ret, ENGINE_FLAGS_BY_ID_COPY) || !ENGINE_set_cmd_defns(ret, dynamic_cmd_defns)) { ENGINE_free(ret); return NULL; } return ret; } void ENGINE_load_dynamic(void) { ENGINE *toadd = engine_dynamic(); if(!toadd) return; ENGINE_add(toadd); /* If the "add" worked, it gets a structural reference. So either way, * we release our just-created reference. */ ENGINE_free(toadd); /* If the "add" didn't work, it was probably a conflict because it was * already added (eg. someone calling ENGINE_load_blah then calling * ENGINE_load_builtin_engines() perhaps). */ ERR_clear_error(); } static int dynamic_init(ENGINE *e) { /* We always return failure - the "dyanamic" engine itself can't be used * for anything. */ return 0; } static int dynamic_finish(ENGINE *e) { /* This should never be called on account of "dynamic_init" always * failing. */ return 0; } static int dynamic_ctrl(ENGINE *e, int cmd, long i, void *p, void (*f)()) { dynamic_data_ctx *ctx = dynamic_get_data_ctx(e); int initialised; if(!ctx) { ENGINEerr(ENGINE_F_DYNAMIC_CTRL,ENGINE_R_NOT_LOADED); return 0; } initialised = ((ctx->dynamic_dso == NULL) ? 0 : 1); /* All our control commands require the ENGINE to be uninitialised */ if(initialised) { ENGINEerr(ENGINE_F_DYNAMIC_CTRL, ENGINE_R_ALREADY_LOADED); return 0; } switch(cmd) { case DYNAMIC_CMD_SO_PATH: /* a NULL 'p' or a string of zero-length is the same thing */ if(p && (strlen((const char *)p) < 1)) p = NULL; if(ctx->DYNAMIC_LIBNAME) OPENSSL_free((void*)ctx->DYNAMIC_LIBNAME); if(p) ctx->DYNAMIC_LIBNAME = BUF_strdup(p); else ctx->DYNAMIC_LIBNAME = NULL; return (ctx->DYNAMIC_LIBNAME ? 1 : 0); case DYNAMIC_CMD_NO_VCHECK: ctx->no_vcheck = ((i == 0) ? 0 : 1); return 1; case DYNAMIC_CMD_ID: /* a NULL 'p' or a string of zero-length is the same thing */ if(p && (strlen((const char *)p) < 1)) p = NULL; if(ctx->engine_id) OPENSSL_free((void*)ctx->engine_id); if(p) ctx->engine_id = BUF_strdup(p); else ctx->engine_id = NULL; return (ctx->engine_id ? 1 : 0); case DYNAMIC_CMD_LIST_ADD: if((i < 0) || (i > 2)) { ENGINEerr(ENGINE_F_DYNAMIC_CTRL, ENGINE_R_INVALID_ARGUMENT); return 0; } ctx->list_add_value = (int)i; return 1; case DYNAMIC_CMD_LOAD: return dynamic_load(e, ctx); default: break; } ENGINEerr(ENGINE_F_DYNAMIC_CTRL,ENGINE_R_CTRL_COMMAND_NOT_IMPLEMENTED); return 0; } static int dynamic_load(ENGINE *e, dynamic_data_ctx *ctx) { ENGINE cpy; dynamic_fns fns; if(!ctx->DYNAMIC_LIBNAME || ((ctx->dynamic_dso = DSO_load(NULL, ctx->DYNAMIC_LIBNAME, NULL, 0)) == NULL)) { ENGINEerr(ENGINE_F_DYNAMIC_LOAD, ENGINE_R_DSO_NOT_FOUND); return 0; } /* We have to find a bind function otherwise it'll always end badly */ if(!(ctx->bind_engine = (dynamic_bind_engine)DSO_bind_func( ctx->dynamic_dso, ctx->DYNAMIC_F2))) { ctx->bind_engine = NULL; DSO_free(ctx->dynamic_dso); ctx->dynamic_dso = NULL; ENGINEerr(ENGINE_F_DYNAMIC_LOAD, ENGINE_R_DSO_FAILURE); return 0; } /* Do we perform version checking? */ if(!ctx->no_vcheck) { unsigned long vcheck_res = 0; /* Now we try to find a version checking function and decide how * to cope with failure if/when it fails. */ ctx->v_check = (dynamic_v_check_fn)DSO_bind_func( ctx->dynamic_dso, ctx->DYNAMIC_F1); if(ctx->v_check) vcheck_res = ctx->v_check(OSSL_DYNAMIC_VERSION); /* We fail if the version checker veto'd the load *or* if it is * deferring to us (by returning its version) and we think it is * too old. */ if(vcheck_res < OSSL_DYNAMIC_OLDEST) { /* Fail */ ctx->bind_engine = NULL; ctx->v_check = NULL; DSO_free(ctx->dynamic_dso); ctx->dynamic_dso = NULL; ENGINEerr(ENGINE_F_DYNAMIC_LOAD, ENGINE_R_VERSION_INCOMPATIBILITY); return 0; } } /* First binary copy the ENGINE structure so that we can roll back if * the hand-over fails */ memcpy(&cpy, e, sizeof(ENGINE)); /* Provide the ERR, "ex_data", memory, and locking callbacks so the * loaded library uses our state rather than its own. FIXME: As noted in * engine.h, much of this would be simplified if each area of code * provided its own "summary" structure of all related callbacks. It * would also increase opaqueness. */ fns.err_fns = ERR_get_implementation(); fns.ex_data_fns = CRYPTO_get_ex_data_implementation(); CRYPTO_get_mem_functions(&fns.mem_fns.malloc_cb, &fns.mem_fns.realloc_cb, &fns.mem_fns.free_cb); fns.lock_fns.lock_locking_cb = CRYPTO_get_locking_callback(); fns.lock_fns.lock_add_lock_cb = CRYPTO_get_add_lock_callback(); fns.lock_fns.dynlock_create_cb = CRYPTO_get_dynlock_create_callback(); fns.lock_fns.dynlock_lock_cb = CRYPTO_get_dynlock_lock_callback(); fns.lock_fns.dynlock_destroy_cb = CRYPTO_get_dynlock_destroy_callback(); /* Now that we've loaded the dynamic engine, make sure no "dynamic" * ENGINE elements will show through. */ engine_set_all_null(e); /* Try to bind the ENGINE onto our own ENGINE structure */ if(!ctx->bind_engine(e, ctx->engine_id, &fns)) { ctx->bind_engine = NULL; ctx->v_check = NULL; DSO_free(ctx->dynamic_dso); ctx->dynamic_dso = NULL; ENGINEerr(ENGINE_F_DYNAMIC_LOAD,ENGINE_R_INIT_FAILED); /* Copy the original ENGINE structure back */ memcpy(e, &cpy, sizeof(ENGINE)); return 0; } /* Do we try to add this ENGINE to the internal list too? */ if(ctx->list_add_value > 0) { if(!ENGINE_add(e)) { /* Do we tolerate this or fail? */ if(ctx->list_add_value > 1) { /* Fail - NB: By this time, it's too late to * rollback, and trying to do so allows the * bind_engine() code to have created leaks. We * just have to fail where we are, after the * ENGINE has changed. */ ENGINEerr(ENGINE_F_DYNAMIC_LOAD, ENGINE_R_CONFLICTING_ENGINE_ID); return 0; } /* Tolerate */ ERR_clear_error(); } } return 1; }