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
 211         || (num = ENGINE_ctrl(e, ENGINE_CTRL_GET_CMD_FROM_NAME,
 212                               0, (void *)cmd_name, NULL)) <= 0) {
 213         /*
 214          * If the command didn't *have* to be supported, we fake success.
 215          * This allows certain settings to be specified for multiple ENGINEs
 216          * and only require a change of ENGINE id (without having to
 217          * selectively apply settings). Eg. changing from a hardware device
 218          * back to the regular software ENGINE without editing the config
 219          * file, etc.
 220          */
 221         if (cmd_optional) {
 222             ERR_clear_error();
 223             return 1;
 224         }
 225         ENGINEerr(ENGINE_F_ENGINE_CTRL_CMD, ENGINE_R_INVALID_CMD_NAME);
 226         return 0;
 227     }
 228     /*
 229      * Force the result of the control command to 0 or 1, for the reasons
 230      * mentioned before.
 231      */
 232     if (ENGINE_ctrl(e, num, i, p, f) > 0)
 233         return 1;
 234     return 0;
 235 }
 236
 237 int ENGINE_ctrl_cmd_string(ENGINE *e, const char *cmd_name, const char *arg,
 238                            int cmd_optional)
 239 {
 240     int num, flags;
 241     long l;
 242     char *ptr;
 243
 244     if (e == NULL || cmd_name == NULL) {
 245         ENGINEerr(ENGINE_F_ENGINE_CTRL_CMD_STRING, ERR_R_PASSED_NULL_PARAMETER);
 246         return 0;
 247     }
 248     if (e->ctrl == NULL
 249         || (num = ENGINE_ctrl(e, ENGINE_CTRL_GET_CMD_FROM_NAME,
 250                               0, (void *)cmd_name, NULL)) <= 0) {
 251         /*
 252          * If the command didn't *have* to be supported, we fake success.
 253          * This allows certain settings to be specified for multiple ENGINEs
 254          * and only require a change of ENGINE id (without having to
 255          * selectively apply settings). Eg. changing from a hardware device
 256          * back to the regular software ENGINE without editing the config
 257          * file, etc.
 258          */
 259         if (cmd_optional) {
 260             ERR_clear_error();
 261             return 1;
 262         }
 263         ENGINEerr(ENGINE_F_ENGINE_CTRL_CMD_STRING, ENGINE_R_INVALID_CMD_NAME);
 264         return 0;
 265     }
 266     if (!ENGINE_cmd_is_executable(e, num)) {
 267         ENGINEerr(ENGINE_F_ENGINE_CTRL_CMD_STRING,
 268                   ENGINE_R_CMD_NOT_EXECUTABLE);
 269         return 0;
 270     }
 271
 272     flags = ENGINE_ctrl(e, ENGINE_CTRL_GET_CMD_FLAGS, num, NULL, NULL);
 273     if (flags < 0) {
 274         /*
 275          * Shouldn't happen, given that ENGINE_cmd_is_executable() returned
 276          * success.
 277          */
 278         ENGINEerr(ENGINE_F_ENGINE_CTRL_CMD_STRING,
 279                   ENGINE_R_INTERNAL_LIST_ERROR);
 280         return 0;
 281     }
 282     /*
 283      * If the command takes no input, there must be no input. And vice versa.
 284      */
 285     if (flags & ENGINE_CMD_FLAG_NO_INPUT) {
 286         if (arg != NULL) {
 287             ENGINEerr(ENGINE_F_ENGINE_CTRL_CMD_STRING,
 288                       ENGINE_R_COMMAND_TAKES_NO_INPUT);
 289             return 0;
 290         }
 291         /*
 292          * We deliberately force the result of ENGINE_ctrl() to 0 or 1 rather
 293          * than returning it as "return data". This is to ensure usage of
 294          * these commands is consistent across applications and that certain
 295          * applications don't understand it one way, and others another.
 296          */
 297         if (ENGINE_ctrl(e, num, 0, (void *)arg, NULL) > 0)
 298             return 1;
 299         return 0;
 300     }
 301     /* So, we require input */
 302     if (arg == NULL) {
 303         ENGINEerr(ENGINE_F_ENGINE_CTRL_CMD_STRING,
 304                   ENGINE_R_COMMAND_TAKES_INPUT);
 305         return 0;
 306     }
 307     /* If it takes string input, that's easy */
 308     if (flags & ENGINE_CMD_FLAG_STRING) {
 309         /* Same explanation as above */
 310         if (ENGINE_ctrl(e, num, 0, (void *)arg, NULL) > 0)
 311             return 1;
 312         return 0;
 313     }
 314     /*
 315      * If it doesn't take numeric either, then it is unsupported for use in a
 316      * config-setting situation, which is what this function is for. This
 317      * should never happen though, because ENGINE_cmd_is_executable() was
 318      * used.
 319      */
 320     if (!(flags & ENGINE_CMD_FLAG_NUMERIC)) {
 321         ENGINEerr(ENGINE_F_ENGINE_CTRL_CMD_STRING,
 322                   ENGINE_R_INTERNAL_LIST_ERROR);
 323         return 0;
 324     }
 325     l = strtol(arg, &ptr, 10);
 326     if ((arg == ptr) || (*ptr != '\0')) {
 327         ENGINEerr(ENGINE_F_ENGINE_CTRL_CMD_STRING,
 328                   ENGINE_R_ARGUMENT_IS_NOT_A_NUMBER);
 329         return 0;
 330     }
 331     /*
 332      * Force the result of the control command to 0 or 1, for the reasons
 333      * mentioned before.
 334      */
 335     if (ENGINE_ctrl(e, num, l, NULL, NULL) > 0)
 336         return 1;
 337     return 0;
 338 }