crypto/engine/eng_ctrl.c

   1 /*
   2  * Copyright 2001-2016 The OpenSSL Project Authors. All Rights Reserved.
   3  *
   4  * Licensed under the OpenSSL license (the "License").  You may not use
   5  * this file except in compliance with the License.  You can obtain a copy
   6  * in the file LICENSE in the source distribution or at
   7  * https://www.openssl.org/source/license.html
   8  */
   9
  10 #include "eng_int.h"
  11
  12 /*
  13  * When querying a ENGINE-specific control command's 'description', this
  14  * string is used if the ENGINE_CMD_DEFN has cmd_desc set to NULL.
  15  */
  16 static const char *int_no_description = "";
  17
  18 /*
  19  * These internal functions handle 'CMD'-related control commands when the
  20  * ENGINE in question has asked us to take care of it (ie. the ENGINE did not
  21  * set the ENGINE_FLAGS_MANUAL_CMD_CTRL flag.
  22  */
  23
  24 static int int_ctrl_cmd_is_null(const ENGINE_CMD_DEFN *defn)
  25 {
  26     if ((defn->cmd_num == 0) || (defn->cmd_name == NULL))
  27         return 1;
  28     return 0;
  29 }
  30
  31 static int int_ctrl_cmd_by_name(const ENGINE_CMD_DEFN *defn, const char *s)
  32 {
  33     int idx = 0;
  34     while (!int_ctrl_cmd_is_null(defn) && (strcmp(defn->cmd_name, s) != 0)) {
  35         idx++;
  36         defn++;
  37     }
  38     if (int_ctrl_cmd_is_null(defn))
  39         /* The given name wasn't found */
  40         return -1;
  41     return idx;
  42 }
  43
  44 static int int_ctrl_cmd_by_num(const ENGINE_CMD_DEFN *defn, unsigned int num)
  45 {
  46     int idx = 0;
  47     /*
  48      * NB: It is stipulated that 'cmd_defn' lists are ordered by cmd_num. So
  49      * our searches don't need to take any longer than necessary.
  50      */
  51     while (!int_ctrl_cmd_is_null(defn) && (defn->cmd_num < num)) {
  52         idx++;
  53         defn++;
  54     }
  55     if (defn->cmd_num == num)
  56         return idx;
  57     /* The given cmd_num wasn't found */
  58     return -1;
  59 }
  60
  61 static int int_ctrl_helper(ENGINE *e, int cmd, long i, void *p,
  62                            void (*f) (void))
  63 {
  64     int idx;
  65     char *s = (char *)p;
  66     /* Take care of the easy one first (eg. it requires no searches) */
  67     if (cmd == ENGINE_CTRL_GET_FIRST_CMD_TYPE) {
  68         if ((e->cmd_defns == NULL) || int_ctrl_cmd_is_null(e->cmd_defns))
  69             return 0;
  70         return e->cmd_defns->cmd_num;
  71     }
  72     /* One or two commands require that "p" be a valid string buffer */
  73     if ((cmd == ENGINE_CTRL_GET_CMD_FROM_NAME) ||
  74         (cmd == ENGINE_CTRL_GET_NAME_FROM_CMD) ||
  75         (cmd == ENGINE_CTRL_GET_DESC_FROM_CMD)) {
  76         if (s == NULL) {
  77             ENGINEerr(ENGINE_F_INT_CTRL_HELPER, ERR_R_PASSED_NULL_PARAMETER);
  78             return -1;
  79         }
  80     }
  81     /* Now handle cmd_name -> cmd_num conversion */
  82     if (cmd == ENGINE_CTRL_GET_CMD_FROM_NAME) {
  83         if ((e->cmd_defns == NULL)
  84             || ((idx = int_ctrl_cmd_by_name(e->cmd_defns, s)) < 0)) {
  85             ENGINEerr(ENGINE_F_INT_CTRL_HELPER, ENGINE_R_INVALID_CMD_NAME);
  86             return -1;
  87         }
  88         return e->cmd_defns[idx].cmd_num;
  89     }
  90     /*
  91      * For the rest of the commands, the 'long' argument must specify a valid
  92      * command number - so we need to conduct a search.
  93      */
  94     if ((e->cmd_defns == NULL) || ((idx = int_ctrl_cmd_by_num(e->cmd_defns,
  95                                                               (unsigned int)
  96                                                               i)) < 0)) {
  97         ENGINEerr(ENGINE_F_INT_CTRL_HELPER, ENGINE_R_INVALID_CMD_NUMBER);
  98         return -1;
  99     }
 100     /* Now the logic splits depending on command type */
 101     switch (cmd) {
 102     case ENGINE_CTRL_GET_NEXT_CMD_TYPE:
 103         idx++;
 104         if (int_ctrl_cmd_is_null(e->cmd_defns + idx))
 105             /* end-of-list */
 106             return 0;
 107         else
 108             return e->cmd_defns[idx].cmd_num;
 109     case ENGINE_CTRL_GET_NAME_LEN_FROM_CMD:
 110         return strlen(e->cmd_defns[idx].cmd_name);
 111     case ENGINE_CTRL_GET_NAME_FROM_CMD:
 112         return BIO_snprintf(s, strlen(e->cmd_defns[idx].cmd_name) + 1,
 113                             "%s", e->cmd_defns[idx].cmd_name);
 114     case ENGINE_CTRL_GET_DESC_LEN_FROM_CMD:
 115         if (e->cmd_defns[idx].cmd_desc)
 116             return strlen(e->cmd_defns[idx].cmd_desc);
 117         return strlen(int_no_description);
 118     case ENGINE_CTRL_GET_DESC_FROM_CMD:
 119         if (e->cmd_defns[idx].cmd_desc)
 120             return BIO_snprintf(s,
 121                                 strlen(e->cmd_defns[idx].cmd_desc) + 1,
 122                                 "%s", e->cmd_defns[idx].cmd_desc);
 123         return BIO_snprintf(s, strlen(int_no_description) + 1, "%s",
 124                             int_no_description);
 125     case ENGINE_CTRL_GET_CMD_FLAGS:
 126         return e->cmd_defns[idx].cmd_flags;
 127     }
 128     /* Shouldn't really be here ... */
 129     ENGINEerr(ENGINE_F_INT_CTRL_HELPER, ENGINE_R_INTERNAL_LIST_ERROR);
 130     return -1;
 131 }
 132
 133 int ENGINE_ctrl(ENGINE *e, int cmd, long i, void *p, void (*f) (void))
 134 {
 135     int ctrl_exists, ref_exists;
 136     if (e == NULL) {
 137         ENGINEerr(ENGINE_F_ENGINE_CTRL, ERR_R_PASSED_NULL_PARAMETER);
 138         return 0;
 139     }
 140     CRYPTO_THREAD_write_lock(global_engine_lock);
 141     ref_exists = ((e->struct_ref > 0) ? 1 : 0);
 142     CRYPTO_THREAD_unlock(global_engine_lock);
 143     ctrl_exists = ((e->ctrl == NULL) ? 0 : 1);
 144     if (!ref_exists) {
 145         ENGINEerr(ENGINE_F_ENGINE_CTRL, ENGINE_R_NO_REFERENCE);
 146         return 0;
 147     }
 148     /*
 149      * Intercept any "root-level" commands before trying to hand them on to
 150      * ctrl() handlers.
 151      */
 152     switch (cmd) {
 153     case ENGINE_CTRL_HAS_CTRL_FUNCTION:
 154         return ctrl_exists;
 155     case ENGINE_CTRL_GET_FIRST_CMD_TYPE:
 156     case ENGINE_CTRL_GET_NEXT_CMD_TYPE:
 157     case ENGINE_CTRL_GET_CMD_FROM_NAME:
 158     case ENGINE_CTRL_GET_NAME_LEN_FROM_CMD:
 159     case ENGINE_CTRL_GET_NAME_FROM_CMD:
 160     case ENGINE_CTRL_GET_DESC_LEN_FROM_CMD:
 161     case ENGINE_CTRL_GET_DESC_FROM_CMD:
 162     case ENGINE_CTRL_GET_CMD_FLAGS:
 163         if (ctrl_exists && !(e->flags & ENGINE_FLAGS_MANUAL_CMD_CTRL))
 164             return int_ctrl_helper(e, cmd, i, p, f);
 165         if (!ctrl_exists) {
 166             ENGINEerr(ENGINE_F_ENGINE_CTRL, ENGINE_R_NO_CONTROL_FUNCTION);
 167             /*
 168              * For these cmd-related functions, failure is indicated by a -1
 169              * return value (because 0 is used as a valid return in some
 170              * places).
 171              */
 172             return -1;
 173         }
 174     default:
 175         break;
 176     }
 177     /* Anything else requires a ctrl() handler to exist. */
 178     if (!ctrl_exists) {
 179         ENGINEerr(ENGINE_F_ENGINE_CTRL, ENGINE_R_NO_CONTROL_FUNCTION);
 180         return 0;
 181     }
 182     return e->ctrl(e, cmd, i, p, f);
 183 }
 184
 185 int ENGINE_cmd_is_executable(ENGINE *e, int cmd)
 186 {
 187     int flags;
 188     if ((flags =
 189          ENGINE_ctrl(e, ENGINE_CTRL_GET_CMD_FLAGS, cmd, NULL, NULL)) < 0) {
 190         ENGINEerr(ENGINE_F_ENGINE_CMD_IS_EXECUTABLE,
 191                   ENGINE_R_INVALID_CMD_NUMBER);
 192         return 0;
 193     }
 194     if (!(flags & ENGINE_CMD_FLAG_NO_INPUT) &&
 195         !(flags & ENGINE_CMD_FLAG_NUMERIC) &&
 196         !(flags & ENGINE_CMD_FLAG_STRING))
 197         return 0;
 198     return 1;
 199 }
 200
 201 int ENGINE_ctrl_cmd(ENGINE *e, const char *cmd_name,
 202                     long i, void *p, void (*f) (void), int cmd_optional)
 203 {
 204     int num;
 205
 206     if ((e == NULL) || (cmd_name == NULL)) {
 207         ENGINEerr(ENGINE_F_ENGINE_CTRL_CMD, ERR_R_PASSED_NULL_PARAMETER);
 208         return 0;
 209     }
 210     if ((e->ctrl == NULL) || ((num = ENGINE_ctrl(e,
 211                                                  ENGINE_CTRL_GET_CMD_FROM_NAME,
 212                                                  0, (void *)cmd_name,
 213                                                  NULL)) <= 0)) {
 214         /*
 215          * If the command didn't *have* to be supported, we fake success.
 216          * This allows certain settings to be specified for multiple ENGINEs
 217          * and only require a change of ENGINE id (without having to
 218          * selectively apply settings). Eg. changing from a hardware device
 219          * back to the regular software ENGINE without editing the config
 220          * file, etc.
 221          */
 222         if (cmd_optional) {
 223             ERR_clear_error();
 224             return 1;
 225         }
 226         ENGINEerr(ENGINE_F_ENGINE_CTRL_CMD, ENGINE_R_INVALID_CMD_NAME);
 227         return 0;
 228     }
 229     /*
 230      * Force the result of the control command to 0 or 1, for the reasons
 231      * mentioned before.
 232      */
 233     if (ENGINE_ctrl(e, num, i, p, f) > 0)
 234         return 1;
 235     return 0;
 236 }
 237
 238 int ENGINE_ctrl_cmd_string(ENGINE *e, const char *cmd_name, const char *arg,
 239                            int cmd_optional)
 240 {
 241     int num, flags;
 242     long l;
 243     char *ptr;
 244     if ((e == NULL) || (cmd_name == NULL)) {
 245         ENGINEerr(ENGINE_F_ENGINE_CTRL_CMD_STRING,
 246                   ERR_R_PASSED_NULL_PARAMETER);
 247         return 0;
 248     }
 249     if ((e->ctrl == NULL) || ((num = ENGINE_ctrl(e,
 250                                                  ENGINE_CTRL_GET_CMD_FROM_NAME,
 251                                                  0, (void *)cmd_name,
 252                                                  NULL)) <= 0)) {
 253         /*
 254          * If the command didn't *have* to be supported, we fake success.
 255          * This allows certain settings to be specified for multiple ENGINEs
 256          * and only require a change of ENGINE id (without having to
 257          * selectively apply settings). Eg. changing from a hardware device
 258          * back to the regular software ENGINE without editing the config
 259          * file, etc.
 260          */
 261         if (cmd_optional) {
 262             ERR_clear_error();
 263             return 1;
 264         }
 265         ENGINEerr(ENGINE_F_ENGINE_CTRL_CMD_STRING, ENGINE_R_INVALID_CMD_NAME);
 266         return 0;
 267     }
 268     if (!ENGINE_cmd_is_executable(e, num)) {
 269         ENGINEerr(ENGINE_F_ENGINE_CTRL_CMD_STRING,
 270                   ENGINE_R_CMD_NOT_EXECUTABLE);
 271         return 0;
 272     }
 273     if ((flags =
 274          ENGINE_ctrl(e, ENGINE_CTRL_GET_CMD_FLAGS, num, NULL, NULL)) < 0) {
 275         /*
 276          * Shouldn't happen, given that ENGINE_cmd_is_executable() returned
 277          * success.
 278          */
 279         ENGINEerr(ENGINE_F_ENGINE_CTRL_CMD_STRING,
 280                   ENGINE_R_INTERNAL_LIST_ERROR);
 281         return 0;
 282     }
 283     /*
 284      * If the command takes no input, there must be no input. And vice versa.
 285      */
 286     if (flags & ENGINE_CMD_FLAG_NO_INPUT) {
 287         if (arg != NULL) {
 288             ENGINEerr(ENGINE_F_ENGINE_CTRL_CMD_STRING,
 289                       ENGINE_R_COMMAND_TAKES_NO_INPUT);
 290             return 0;
 291         }
 292         /*
 293          * We deliberately force the result of ENGINE_ctrl() to 0 or 1 rather
 294          * than returning it as "return data". This is to ensure usage of
 295          * these commands is consistent across applications and that certain
 296          * applications don't understand it one way, and others another.
 297          */
 298         if (ENGINE_ctrl(e, num, 0, (void *)arg, NULL) > 0)
 299             return 1;
 300         return 0;
 301     }
 302     /* So, we require input */
 303     if (arg == NULL) {
 304         ENGINEerr(ENGINE_F_ENGINE_CTRL_CMD_STRING,
 305                   ENGINE_R_COMMAND_TAKES_INPUT);
 306         return 0;
 307     }
 308     /* If it takes string input, that's easy */
 309     if (flags & ENGINE_CMD_FLAG_STRING) {
 310         /* Same explanation as above */
 311         if (ENGINE_ctrl(e, num, 0, (void *)arg, NULL) > 0)
 312             return 1;
 313         return 0;
 314     }
 315     /*
 316      * If it doesn't take numeric either, then it is unsupported for use in a
 317      * config-setting situation, which is what this function is for. This
 318      * should never happen though, because ENGINE_cmd_is_executable() was
 319      * used.
 320      */
 321     if (!(flags & ENGINE_CMD_FLAG_NUMERIC)) {
 322         ENGINEerr(ENGINE_F_ENGINE_CTRL_CMD_STRING,
 323                   ENGINE_R_INTERNAL_LIST_ERROR);
 324         return 0;
 325     }
 326     l = strtol(arg, &ptr, 10);
 327     if ((arg == ptr) || (*ptr != '\0')) {
 328         ENGINEerr(ENGINE_F_ENGINE_CTRL_CMD_STRING,
 329                   ENGINE_R_ARGUMENT_IS_NOT_A_NUMBER);
 330         return 0;
 331     }
 332     /*
 333      * Force the result of the control command to 0 or 1, for the reasons
 334      * mentioned before.
 335      */
 336     if (ENGINE_ctrl(e, num, l, NULL, NULL) > 0)
 337         return 1;
 338     return 0;
 339 }