lib/libcrypto/engine/eng_ctrl.c

   1 /* $OpenBSD: eng_ctrl.c,v 1.11 2017/01/29 17:49:23 beck Exp $ */
   2 /* ====================================================================
   3  * Copyright (c) 1999-2001 The OpenSSL Project.  All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  *
   9  * 1. Redistributions of source code must retain the above copyright
  10  *    notice, this list of conditions and the following disclaimer.
  11  *
  12  * 2. Redistributions in binary form must reproduce the above copyright
  13  *    notice, this list of conditions and the following disclaimer in
  14  *    the documentation and/or other materials provided with the
  15  *    distribution.
  16  *
  17  * 3. All advertising materials mentioning features or use of this
  18  *    software must display the following acknowledgment:
  19  *    "This product includes software developed by the OpenSSL Project
  20  *    for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"
  21  *
  22  * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
  23  *    endorse or promote products derived from this software without
  24  *    prior written permission. For written permission, please contact
  25  *    licensing@OpenSSL.org.
  26  *
  27  * 5. Products derived from this software may not be called "OpenSSL"
  28  *    nor may "OpenSSL" appear in their names without prior written
  29  *    permission of the OpenSSL Project.
  30  *
  31  * 6. Redistributions of any form whatsoever must retain the following
  32  *    acknowledgment:
  33  *    "This product includes software developed by the OpenSSL Project
  34  *    for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"
  35  *
  36  * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
  37  * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  38  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  39  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
  40  * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  41  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  42  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  43  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  44  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
  45  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  46  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
  47  * OF THE POSSIBILITY OF SUCH DAMAGE.
  48  * ====================================================================
  49  *
  50  * This product includes cryptographic software written by Eric Young
  51  * (eay@cryptsoft.com).  This product includes software written by Tim
  52  * Hudson (tjh@cryptsoft.com).
  53  *
  54  */
  55
  56 #include <string.h>
  57
  58 #include <openssl/err.h>
  59
  60 #include "eng_int.h"
  61
  62 /* When querying a ENGINE-specific control command's 'description', this string
  63  * is used if the ENGINE_CMD_DEFN has cmd_desc set to NULL. */
  64 static const char *int_no_description = "";
  65
  66 /* These internal functions handle 'CMD'-related control commands when the
  67  * ENGINE in question has asked us to take care of it (ie. the ENGINE did not
  68  * set the ENGINE_FLAGS_MANUAL_CMD_CTRL flag. */
  69
  70 static int
  71 int_ctrl_cmd_is_null(const ENGINE_CMD_DEFN *defn)
  72 {
  73         if ((defn->cmd_num == 0) || (defn->cmd_name == NULL))
  74                 return 1;
  75         return 0;
  76 }
  77
  78 static int
  79 int_ctrl_cmd_by_name(const ENGINE_CMD_DEFN *defn, const char *s)
  80 {
  81         int idx = 0;
  82         while (!int_ctrl_cmd_is_null(defn) &&
  83             (strcmp(defn->cmd_name, s) != 0)) {
  84                 idx++;
  85                 defn++;
  86         }
  87         if (int_ctrl_cmd_is_null(defn))
  88                 /* The given name wasn't found */
  89                 return -1;
  90         return idx;
  91 }
  92
  93 static int
  94 int_ctrl_cmd_by_num(const ENGINE_CMD_DEFN *defn, unsigned int num)
  95 {
  96         int idx = 0;
  97         /* NB: It is stipulated that 'cmd_defn' lists are ordered by cmd_num. So
  98          * our searches don't need to take any longer than necessary. */
  99         while (!int_ctrl_cmd_is_null(defn) && (defn->cmd_num < num)) {
 100                 idx++;
 101                 defn++;
 102         }
 103         if (defn->cmd_num == num)
 104                 return idx;
 105         /* The given cmd_num wasn't found */
 106         return -1;
 107 }
 108
 109 static int
 110 int_ctrl_helper(ENGINE *e, int cmd, long i, void *p, void (*f)(void))
 111 {
 112         int idx;
 113         int ret;
 114         char *s = (char *)p;
 115
 116         /* Take care of the easy one first (eg. it requires no searches) */
 117         if (cmd == ENGINE_CTRL_GET_FIRST_CMD_TYPE) {
 118                 if ((e->cmd_defns == NULL) ||
 119                     int_ctrl_cmd_is_null(e->cmd_defns))
 120                         return 0;
 121                 return e->cmd_defns->cmd_num;
 122         }
 123         /* One or two commands require that "p" be a valid string buffer */
 124         if ((cmd == ENGINE_CTRL_GET_CMD_FROM_NAME) ||
 125             (cmd == ENGINE_CTRL_GET_NAME_FROM_CMD) ||
 126             (cmd == ENGINE_CTRL_GET_DESC_FROM_CMD)) {
 127                 if (s == NULL) {
 128                         ENGINEerror(ERR_R_PASSED_NULL_PARAMETER);
 129                         return -1;
 130                 }
 131         }
 132         /* Now handle cmd_name -> cmd_num conversion */
 133         if (cmd == ENGINE_CTRL_GET_CMD_FROM_NAME) {
 134                 if ((e->cmd_defns == NULL) ||
 135                     ((idx = int_ctrl_cmd_by_name(e->cmd_defns, s)) < 0)) {
 136                         ENGINEerror(ENGINE_R_INVALID_CMD_NAME);
 137                         return -1;
 138                 }
 139                 return e->cmd_defns[idx].cmd_num;
 140         }
 141         /* For the rest of the commands, the 'long' argument must specify a
 142          * valie command number - so we need to conduct a search. */
 143         if ((e->cmd_defns == NULL) ||
 144             ((idx = int_ctrl_cmd_by_num(e->cmd_defns, (unsigned int)i)) < 0)) {
 145                 ENGINEerror(ENGINE_R_INVALID_CMD_NUMBER);
 146                 return -1;
 147         }
 148         /* Now the logic splits depending on command type */
 149         switch (cmd) {
 150         case ENGINE_CTRL_GET_NEXT_CMD_TYPE:
 151                 idx++;
 152                 if (int_ctrl_cmd_is_null(e->cmd_defns + idx))
 153                         /* end-of-list */
 154                         return 0;
 155                 else
 156                         return e->cmd_defns[idx].cmd_num;
 157         case ENGINE_CTRL_GET_NAME_LEN_FROM_CMD:
 158                 return strlen(e->cmd_defns[idx].cmd_name);
 159         case ENGINE_CTRL_GET_NAME_FROM_CMD:
 160                 ret = snprintf(s, strlen(e->cmd_defns[idx].cmd_name) + 1,
 161                     "%s", e->cmd_defns[idx].cmd_name);
 162                 if (ret >= (strlen(e->cmd_defns[idx].cmd_name) + 1))
 163                         ret = -1;
 164                 return ret;
 165         case ENGINE_CTRL_GET_DESC_LEN_FROM_CMD:
 166                 if (e->cmd_defns[idx].cmd_desc)
 167                         return strlen(e->cmd_defns[idx].cmd_desc);
 168                 return strlen(int_no_description);
 169         case ENGINE_CTRL_GET_DESC_FROM_CMD:
 170                 if (e->cmd_defns[idx].cmd_desc) {
 171                         ret = snprintf(s,
 172                             strlen(e->cmd_defns[idx].cmd_desc) + 1,
 173                             "%s", e->cmd_defns[idx].cmd_desc);
 174                         if (ret >= strlen(e->cmd_defns[idx].cmd_desc) + 1)
 175                                 ret = -1;
 176                         return ret;
 177                 }
 178                 ret = snprintf(s, strlen(int_no_description) + 1, "%s",
 179                     int_no_description);
 180                 if (ret >= strlen(int_no_description) + 1)
 181                         ret = -1;
 182                 return ret;
 183         case ENGINE_CTRL_GET_CMD_FLAGS:
 184                 return e->cmd_defns[idx].cmd_flags;
 185         }
 186
 187         /* Shouldn't really be here ... */
 188         ENGINEerror(ENGINE_R_INTERNAL_LIST_ERROR);
 189         return -1;
 190 }
 191
 192 int
 193 ENGINE_ctrl(ENGINE *e, int cmd, long i, void *p, void (*f)(void))
 194 {
 195         int ctrl_exists, ref_exists;
 196
 197         if (e == NULL) {
 198                 ENGINEerror(ERR_R_PASSED_NULL_PARAMETER);
 199                 return 0;
 200         }
 201         CRYPTO_w_lock(CRYPTO_LOCK_ENGINE);
 202         ref_exists = ((e->struct_ref > 0) ? 1 : 0);
 203         CRYPTO_w_unlock(CRYPTO_LOCK_ENGINE);
 204         ctrl_exists = ((e->ctrl == NULL) ? 0 : 1);
 205         if (!ref_exists) {
 206                 ENGINEerror(ENGINE_R_NO_REFERENCE);
 207                 return 0;
 208         }
 209         /* Intercept any "root-level" commands before trying to hand them on to
 210          * ctrl() handlers. */
 211         switch (cmd) {
 212         case ENGINE_CTRL_HAS_CTRL_FUNCTION:
 213                 return ctrl_exists;
 214         case ENGINE_CTRL_GET_FIRST_CMD_TYPE:
 215         case ENGINE_CTRL_GET_NEXT_CMD_TYPE:
 216         case ENGINE_CTRL_GET_CMD_FROM_NAME:
 217         case ENGINE_CTRL_GET_NAME_LEN_FROM_CMD:
 218         case ENGINE_CTRL_GET_NAME_FROM_CMD:
 219         case ENGINE_CTRL_GET_DESC_LEN_FROM_CMD:
 220         case ENGINE_CTRL_GET_DESC_FROM_CMD:
 221         case ENGINE_CTRL_GET_CMD_FLAGS:
 222                 if (ctrl_exists && !(e->flags & ENGINE_FLAGS_MANUAL_CMD_CTRL))
 223                         return int_ctrl_helper(e, cmd, i, p, f);
 224                 if (!ctrl_exists) {
 225                         ENGINEerror(ENGINE_R_NO_CONTROL_FUNCTION);
 226                         /* For these cmd-related functions, failure is indicated
 227                          * by a -1 return value (because 0 is used as a valid
 228                          * return in some places). */
 229                         return -1;
 230                 }
 231         default:
 232                 break;
 233         }
 234         /* Anything else requires a ctrl() handler to exist. */
 235         if (!ctrl_exists) {
 236                 ENGINEerror(ENGINE_R_NO_CONTROL_FUNCTION);
 237                 return 0;
 238         }
 239         return e->ctrl(e, cmd, i, p, f);
 240 }
 241
 242 int
 243 ENGINE_cmd_is_executable(ENGINE *e, int cmd)
 244 {
 245         int flags;
 246
 247         if ((flags = ENGINE_ctrl(e, ENGINE_CTRL_GET_CMD_FLAGS, cmd,
 248             NULL, NULL)) < 0) {
 249                 ENGINEerror(ENGINE_R_INVALID_CMD_NUMBER);
 250                 return 0;
 251         }
 252         if (!(flags & ENGINE_CMD_FLAG_NO_INPUT) &&
 253             !(flags & ENGINE_CMD_FLAG_NUMERIC) &&
 254             !(flags & ENGINE_CMD_FLAG_STRING))
 255                 return 0;
 256         return 1;
 257 }
 258
 259 int
 260 ENGINE_ctrl_cmd(ENGINE *e, const char *cmd_name, long i, void *p,
 261     void (*f)(void), int cmd_optional)
 262 {
 263         int num;
 264
 265         if ((e == NULL) || (cmd_name == NULL)) {
 266                 ENGINEerror(ERR_R_PASSED_NULL_PARAMETER);
 267                 return 0;
 268         }
 269         if ((e->ctrl == NULL) ||
 270             ((num = ENGINE_ctrl(e, ENGINE_CTRL_GET_CMD_FROM_NAME,
 271             0, (void *)cmd_name, NULL)) <= 0)) {
 272                 /* If the command didn't *have* to be supported, we fake
 273                  * success. This allows certain settings to be specified for
 274                  * multiple ENGINEs and only require a change of ENGINE id
 275                  * (without having to selectively apply settings). Eg. changing
 276                  * from a hardware device back to the regular software ENGINE
 277                  * without editing the config file, etc. */
 278                 if (cmd_optional) {
 279                         ERR_clear_error();
 280                         return 1;
 281                 }
 282                 ENGINEerror(ENGINE_R_INVALID_CMD_NAME);
 283                 return 0;
 284         }
 285
 286         /* Force the result of the control command to 0 or 1, for the reasons
 287          * mentioned before. */
 288         if (ENGINE_ctrl(e, num, i, p, f) > 0)
 289                 return 1;
 290
 291         return 0;
 292 }
 293
 294 int
 295 ENGINE_ctrl_cmd_string(ENGINE *e, const char *cmd_name, const char *arg,
 296     int cmd_optional)
 297 {
 298         int num, flags;
 299         long l;
 300         char *ptr;
 301
 302         if ((e == NULL) || (cmd_name == NULL)) {
 303                 ENGINEerror(ERR_R_PASSED_NULL_PARAMETER);
 304                 return 0;
 305         }
 306         if ((e->ctrl == NULL) ||
 307             ((num = ENGINE_ctrl(e, ENGINE_CTRL_GET_CMD_FROM_NAME, 0,
 308             (void *)cmd_name, NULL)) <= 0)) {
 309                 /* If the command didn't *have* to be supported, we fake
 310                  * success. This allows certain settings to be specified for
 311                  * multiple ENGINEs and only require a change of ENGINE id
 312                  * (without having to selectively apply settings). Eg. changing
 313                  * from a hardware device back to the regular software ENGINE
 314                  * without editing the config file, etc. */
 315                 if (cmd_optional) {
 316                         ERR_clear_error();
 317                         return 1;
 318                 }
 319                 ENGINEerror(ENGINE_R_INVALID_CMD_NAME);
 320                 return 0;
 321         }
 322         if (!ENGINE_cmd_is_executable(e, num)) {
 323                 ENGINEerror(ENGINE_R_CMD_NOT_EXECUTABLE);
 324                 return 0;
 325         }
 326         if ((flags = ENGINE_ctrl(e, ENGINE_CTRL_GET_CMD_FLAGS, num,
 327             NULL, NULL)) < 0) {
 328                 /* Shouldn't happen, given that ENGINE_cmd_is_executable()
 329                  * returned success. */
 330                 ENGINEerror(ENGINE_R_INTERNAL_LIST_ERROR);
 331                 return 0;
 332         }
 333         /* If the command takes no input, there must be no input. And vice
 334          * versa. */
 335         if (flags & ENGINE_CMD_FLAG_NO_INPUT) {
 336                 if (arg != NULL) {
 337                         ENGINEerror(ENGINE_R_COMMAND_TAKES_NO_INPUT);
 338                         return 0;
 339                 }
 340                 /* We deliberately force the result of ENGINE_ctrl() to 0 or 1
 341                  * rather than returning it as "return data". This is to ensure
 342                  * usage of these commands is consistent across applications and
 343                  * that certain applications don't understand it one way, and
 344                  * others another. */
 345                 if (ENGINE_ctrl(e, num, 0, (void *)arg, NULL) > 0)
 346                         return 1;
 347                 return 0;
 348         }
 349         /* So, we require input */
 350         if (arg == NULL) {
 351                 ENGINEerror(ENGINE_R_COMMAND_TAKES_INPUT);
 352                 return 0;
 353         }
 354         /* If it takes string input, that's easy */
 355         if (flags & ENGINE_CMD_FLAG_STRING) {
 356                 /* Same explanation as above */
 357                 if (ENGINE_ctrl(e, num, 0, (void *)arg, NULL) > 0)
 358                         return 1;
 359                 return 0;
 360         }
 361         /* If it doesn't take numeric either, then it is unsupported for use in
 362          * a config-setting situation, which is what this function is for. This
 363          * should never happen though, because ENGINE_cmd_is_executable() was
 364          * used. */
 365         if (!(flags & ENGINE_CMD_FLAG_NUMERIC)) {
 366                 ENGINEerror(ENGINE_R_INTERNAL_LIST_ERROR);
 367                 return 0;
 368         }
 369         l = strtol(arg, &ptr, 10);
 370         if ((arg == ptr) || (*ptr != '\0')) {
 371                 ENGINEerror(ENGINE_R_ARGUMENT_IS_NOT_A_NUMBER);
 372                 return 0;
 373         }
 374         /* Force the result of the control command to 0 or 1, for the reasons
 375          * mentioned before. */
 376         if (ENGINE_ctrl(e, num, l, NULL, NULL) > 0)
 377                 return 1;
 378         return 0;
 379 }