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 sprintf(s, "%s", e->cmd_defns[idx].cmd_name);
 113     case ENGINE_CTRL_GET_DESC_LEN_FROM_CMD:
 114         if (e->cmd_defns[idx].cmd_desc)
 115             return strlen(e->cmd_defns[idx].cmd_desc);
 116         return strlen(int_no_description);
 117     case ENGINE_CTRL_GET_DESC_FROM_CMD:
 118         if (e->cmd_defns[idx].cmd_desc)
 119             return sprintf(s, "%s", e->cmd_defns[idx].cmd_desc);
 120         return sprintf(s, "%s", int_no_description);
 121     case ENGINE_CTRL_GET_CMD_FLAGS:
 122         return e->cmd_defns[idx].cmd_flags;
 123     }
 124     /* Shouldn't really be here ... */
 125     ENGINEerr(ENGINE_F_INT_CTRL_HELPER, ENGINE_R_INTERNAL_LIST_ERROR);
 126     return -1;
 127 }
 128
 129 int ENGINE_ctrl(ENGINE *e, int cmd, long i, void *p, void (*f) (void))
 130 {
 131     int ctrl_exists, ref_exists;
 132     if (e == NULL) {
 133         ENGINEerr(ENGINE_F_ENGINE_CTRL, ERR_R_PASSED_NULL_PARAMETER);
 134         return 0;
 135     }
 136     CRYPTO_THREAD_write_lock(global_engine_lock);
 137     ref_exists = ((e->struct_ref > 0) ? 1 : 0);
 138     CRYPTO_THREAD_unlock(global_engine_lock);
 139     ctrl_exists = ((e->ctrl == NULL) ? 0 : 1);
 140     if (!ref_exists) {
 141         ENGINEerr(ENGINE_F_ENGINE_CTRL, ENGINE_R_NO_REFERENCE);
 142         return 0;
 143     }
 144     /*
 145      * Intercept any "root-level" commands before trying to hand them on to
 146      * ctrl() handlers.
 147      */
 148     switch (cmd) {
 149     case ENGINE_CTRL_HAS_CTRL_FUNCTION:
 150         return ctrl_exists;
 151     case ENGINE_CTRL_GET_FIRST_CMD_TYPE:
 152     case ENGINE_CTRL_GET_NEXT_CMD_TYPE:
 153     case ENGINE_CTRL_GET_CMD_FROM_NAME:
 154     case ENGINE_CTRL_GET_NAME_LEN_FROM_CMD:
 155     case ENGINE_CTRL_GET_NAME_FROM_CMD:
 156     case ENGINE_CTRL_GET_DESC_LEN_FROM_CMD:
 157     case ENGINE_CTRL_GET_DESC_FROM_CMD:
 158     case ENGINE_CTRL_GET_CMD_FLAGS:
 159         if (ctrl_exists && !(e->flags & ENGINE_FLAGS_MANUAL_CMD_CTRL))
 160             return int_ctrl_helper(e, cmd, i, p, f);
 161         if (!ctrl_exists) {
 162             ENGINEerr(ENGINE_F_ENGINE_CTRL, ENGINE_R_NO_CONTROL_FUNCTION);
 163             /*
 164              * For these cmd-related functions, failure is indicated by a -1
 165              * return value (because 0 is used as a valid return in some
 166              * places).
 167              */
 168             return -1;
 169         }
 170     default:
 171         break;
 172     }
 173     /* Anything else requires a ctrl() handler to exist. */
 174     if (!ctrl_exists) {
 175         ENGINEerr(ENGINE_F_ENGINE_CTRL, ENGINE_R_NO_CONTROL_FUNCTION);
 176         return 0;
 177     }
 178     return e->ctrl(e, cmd, i, p, f);
 179 }
 180
 181 int ENGINE_cmd_is_executable(ENGINE *e, int cmd)
 182 {
 183     int flags;
 184     if ((flags =
 185          ENGINE_ctrl(e, ENGINE_CTRL_GET_CMD_FLAGS, cmd, NULL, NULL)) < 0) {
 186         ENGINEerr(ENGINE_F_ENGINE_CMD_IS_EXECUTABLE,
 187                   ENGINE_R_INVALID_CMD_NUMBER);
 188         return 0;
 189     }
 190     if (!(flags & ENGINE_CMD_FLAG_NO_INPUT) &&
 191         !(flags & ENGINE_CMD_FLAG_NUMERIC) &&
 192         !(flags & ENGINE_CMD_FLAG_STRING))
 193         return 0;
 194     return 1;
 195 }
 196
 197 int ENGINE_ctrl_cmd(ENGINE *e, const char *cmd_name,
 198                     long i, void *p, void (*f) (void), int cmd_optional)
 199 {
 200     int num;
 201
 202     if (e == NULL || cmd_name == NULL) {
 203         ENGINEerr(ENGINE_F_ENGINE_CTRL_CMD, ERR_R_PASSED_NULL_PARAMETER);
 204         return 0;
 205     }
 206     if (e->ctrl == NULL
 207         || (num = ENGINE_ctrl(e, ENGINE_CTRL_GET_CMD_FROM_NAME,
 208                               0, (void *)cmd_name, NULL)) <= 0) {
 209         /*
 210          * If the command didn't *have* to be supported, we fake success.
 211          * This allows certain settings to be specified for multiple ENGINEs
 212          * and only require a change of ENGINE id (without having to
 213          * selectively apply settings). Eg. changing from a hardware device
 214          * back to the regular software ENGINE without editing the config
 215          * file, etc.
 216          */
 217         if (cmd_optional) {
 218             ERR_clear_error();
 219             return 1;
 220         }
 221         ENGINEerr(ENGINE_F_ENGINE_CTRL_CMD, ENGINE_R_INVALID_CMD_NAME);
 222         return 0;
 223     }
 224     /*
 225      * Force the result of the control command to 0 or 1, for the reasons
 226      * mentioned before.
 227      */
 228     if (ENGINE_ctrl(e, num, i, p, f) > 0)
 229         return 1;
 230     return 0;
 231 }
 232
 233 int ENGINE_ctrl_cmd_string(ENGINE *e, const char *cmd_name, const char *arg,
 234                            int cmd_optional)
 235 {
 236     int num, flags;
 237     long l;
 238     char *ptr;
 239
 240     if (e == NULL || cmd_name == NULL) {
 241         ENGINEerr(ENGINE_F_ENGINE_CTRL_CMD_STRING, ERR_R_PASSED_NULL_PARAMETER);
 242         return 0;
 243     }
 244     if (e->ctrl == NULL
 245         || (num = ENGINE_ctrl(e, ENGINE_CTRL_GET_CMD_FROM_NAME,
 246                               0, (void *)cmd_name, NULL)) <= 0) {
 247         /*
 248          * If the command didn't *have* to be supported, we fake success.
 249          * This allows certain settings to be specified for multiple ENGINEs
 250          * and only require a change of ENGINE id (without having to
 251          * selectively apply settings). Eg. changing from a hardware device
 252          * back to the regular software ENGINE without editing the config
 253          * file, etc.
 254          */
 255         if (cmd_optional) {
 256             ERR_clear_error();
 257             return 1;
 258         }
 259         ENGINEerr(ENGINE_F_ENGINE_CTRL_CMD_STRING, ENGINE_R_INVALID_CMD_NAME);
 260         return 0;
 261     }
 262     if (!ENGINE_cmd_is_executable(e, num)) {
 263         ENGINEerr(ENGINE_F_ENGINE_CTRL_CMD_STRING,
 264                   ENGINE_R_CMD_NOT_EXECUTABLE);
 265         return 0;
 266     }
 267
 268     flags = ENGINE_ctrl(e, ENGINE_CTRL_GET_CMD_FLAGS, num, NULL, NULL);
 269     if (flags < 0) {
 270         /*
 271          * Shouldn't happen, given that ENGINE_cmd_is_executable() returned
 272          * success.
 273          */
 274         ENGINEerr(ENGINE_F_ENGINE_CTRL_CMD_STRING,
 275                   ENGINE_R_INTERNAL_LIST_ERROR);
 276         return 0;
 277     }
 278     /*
 279      * If the command takes no input, there must be no input. And vice versa.
 280      */
 281     if (flags & ENGINE_CMD_FLAG_NO_INPUT) {
 282         if (arg != NULL) {
 283             ENGINEerr(ENGINE_F_ENGINE_CTRL_CMD_STRING,
 284                       ENGINE_R_COMMAND_TAKES_NO_INPUT);
 285             return 0;
 286         }
 287         /*
 288          * We deliberately force the result of ENGINE_ctrl() to 0 or 1 rather
 289          * than returning it as "return data". This is to ensure usage of
 290          * these commands is consistent across applications and that certain
 291          * applications don't understand it one way, and others another.
 292          */
 293         if (ENGINE_ctrl(e, num, 0, (void *)arg, NULL) > 0)
 294             return 1;
 295         return 0;
 296     }
 297     /* So, we require input */
 298     if (arg == NULL) {
 299         ENGINEerr(ENGINE_F_ENGINE_CTRL_CMD_STRING,
 300                   ENGINE_R_COMMAND_TAKES_INPUT);
 301         return 0;
 302     }
 303     /* If it takes string input, that's easy */
 304     if (flags & ENGINE_CMD_FLAG_STRING) {
 305         /* Same explanation as above */
 306         if (ENGINE_ctrl(e, num, 0, (void *)arg, NULL) > 0)
 307             return 1;
 308         return 0;
 309     }
 310     /*
 311      * If it doesn't take numeric either, then it is unsupported for use in a
 312      * config-setting situation, which is what this function is for. This
 313      * should never happen though, because ENGINE_cmd_is_executable() was
 314      * used.
 315      */
 316     if (!(flags & ENGINE_CMD_FLAG_NUMERIC)) {
 317         ENGINEerr(ENGINE_F_ENGINE_CTRL_CMD_STRING,
 318                   ENGINE_R_INTERNAL_LIST_ERROR);
 319         return 0;
 320     }
 321     l = strtol(arg, &ptr, 10);
 322     if ((arg == ptr) || (*ptr != '\0')) {
 323         ENGINEerr(ENGINE_F_ENGINE_CTRL_CMD_STRING,
 324                   ENGINE_R_ARGUMENT_IS_NOT_A_NUMBER);
 325         return 0;
 326     }
 327     /*
 328      * Force the result of the control command to 0 or 1, for the reasons
 329      * mentioned before.
 330      */
 331     if (ENGINE_ctrl(e, num, l, NULL, NULL) > 0)
 332         return 1;
 333     return 0;
 334 }