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     const ENGINE_CMD_DEFN *cdp;
  67
  68     /* Take care of the easy one first (eg. it requires no searches) */
  69     if (cmd == ENGINE_CTRL_GET_FIRST_CMD_TYPE) {
  70         if ((e->cmd_defns == NULL) || int_ctrl_cmd_is_null(e->cmd_defns))
  71             return 0;
  72         return e->cmd_defns->cmd_num;
  73     }
  74     /* One or two commands require that "p" be a valid string buffer */
  75     if ((cmd == ENGINE_CTRL_GET_CMD_FROM_NAME) ||
  76         (cmd == ENGINE_CTRL_GET_NAME_FROM_CMD) ||
  77         (cmd == ENGINE_CTRL_GET_DESC_FROM_CMD)) {
  78         if (s == NULL) {
  79             ENGINEerr(ENGINE_F_INT_CTRL_HELPER, ERR_R_PASSED_NULL_PARAMETER);
  80             return -1;
  81         }
  82     }
  83     /* Now handle cmd_name -> cmd_num conversion */
  84     if (cmd == ENGINE_CTRL_GET_CMD_FROM_NAME) {
  85         if ((e->cmd_defns == NULL)
  86             || ((idx = int_ctrl_cmd_by_name(e->cmd_defns, s)) < 0)) {
  87             ENGINEerr(ENGINE_F_INT_CTRL_HELPER, ENGINE_R_INVALID_CMD_NAME);
  88             return -1;
  89         }
  90         return e->cmd_defns[idx].cmd_num;
  91     }
  92     /*
  93      * For the rest of the commands, the 'long' argument must specify a valid
  94      * command number - so we need to conduct a search.
  95      */
  96     if ((e->cmd_defns == NULL)
  97         || ((idx = int_ctrl_cmd_by_num(e->cmd_defns, (unsigned int)i)) < 0)) {
  98         ENGINEerr(ENGINE_F_INT_CTRL_HELPER, ENGINE_R_INVALID_CMD_NUMBER);
  99         return -1;
 100     }
 101     /* Now the logic splits depending on command type */
 102     cdp = &e->cmd_defns[idx];
 103     switch (cmd) {
 104     case ENGINE_CTRL_GET_NEXT_CMD_TYPE:
 105         cdp++;
 106         return int_ctrl_cmd_is_null(cdp) ? 0 : cdp->cmd_num;
 107     case ENGINE_CTRL_GET_NAME_LEN_FROM_CMD:
 108         return strlen(cdp->cmd_name);
 109     case ENGINE_CTRL_GET_NAME_FROM_CMD:
 110         return strlen(strcpy(s, cdp->cmd_name));
 111     case ENGINE_CTRL_GET_DESC_LEN_FROM_CMD:
 112         return strlen(cdp->cmd_desc == NULL ? int_no_description
 113                                             : cdp->cmd_desc);
 114     case ENGINE_CTRL_GET_DESC_FROM_CMD:
 115         return strlen(strcpy(s, cdp->cmd_desc == NULL ? int_no_description
 116                                                       : cdp->cmd_desc));
 117     case ENGINE_CTRL_GET_CMD_FLAGS:
 118         return cdp->cmd_flags;
 119     }
 120     /* Shouldn't really be here ... */
 121     ENGINEerr(ENGINE_F_INT_CTRL_HELPER, ENGINE_R_INTERNAL_LIST_ERROR);
 122     return -1;
 123 }
 124
 125 int ENGINE_ctrl(ENGINE *e, int cmd, long i, void *p, void (*f) (void))
 126 {
 127     int ctrl_exists, ref_exists;
 128     if (e == NULL) {
 129         ENGINEerr(ENGINE_F_ENGINE_CTRL, ERR_R_PASSED_NULL_PARAMETER);
 130         return 0;
 131     }
 132     CRYPTO_THREAD_write_lock(global_engine_lock);
 133     ref_exists = ((e->struct_ref > 0) ? 1 : 0);
 134     CRYPTO_THREAD_unlock(global_engine_lock);
 135     ctrl_exists = ((e->ctrl == NULL) ? 0 : 1);
 136     if (!ref_exists) {
 137         ENGINEerr(ENGINE_F_ENGINE_CTRL, ENGINE_R_NO_REFERENCE);
 138         return 0;
 139     }
 140     /*
 141      * Intercept any "root-level" commands before trying to hand them on to
 142      * ctrl() handlers.
 143      */
 144     switch (cmd) {
 145     case ENGINE_CTRL_HAS_CTRL_FUNCTION:
 146         return ctrl_exists;
 147     case ENGINE_CTRL_GET_FIRST_CMD_TYPE:
 148     case ENGINE_CTRL_GET_NEXT_CMD_TYPE:
 149     case ENGINE_CTRL_GET_CMD_FROM_NAME:
 150     case ENGINE_CTRL_GET_NAME_LEN_FROM_CMD:
 151     case ENGINE_CTRL_GET_NAME_FROM_CMD:
 152     case ENGINE_CTRL_GET_DESC_LEN_FROM_CMD:
 153     case ENGINE_CTRL_GET_DESC_FROM_CMD:
 154     case ENGINE_CTRL_GET_CMD_FLAGS:
 155         if (ctrl_exists && !(e->flags & ENGINE_FLAGS_MANUAL_CMD_CTRL))
 156             return int_ctrl_helper(e, cmd, i, p, f);
 157         if (!ctrl_exists) {
 158             ENGINEerr(ENGINE_F_ENGINE_CTRL, ENGINE_R_NO_CONTROL_FUNCTION);
 159             /*
 160              * For these cmd-related functions, failure is indicated by a -1
 161              * return value (because 0 is used as a valid return in some
 162              * places).
 163              */
 164             return -1;
 165         }
 166     default:
 167         break;
 168     }
 169     /* Anything else requires a ctrl() handler to exist. */
 170     if (!ctrl_exists) {
 171         ENGINEerr(ENGINE_F_ENGINE_CTRL, ENGINE_R_NO_CONTROL_FUNCTION);
 172         return 0;
 173     }
 174     return e->ctrl(e, cmd, i, p, f);
 175 }
 176
 177 int ENGINE_cmd_is_executable(ENGINE *e, int cmd)
 178 {
 179     int flags;
 180     if ((flags =
 181          ENGINE_ctrl(e, ENGINE_CTRL_GET_CMD_FLAGS, cmd, NULL, NULL)) < 0) {
 182         ENGINEerr(ENGINE_F_ENGINE_CMD_IS_EXECUTABLE,
 183                   ENGINE_R_INVALID_CMD_NUMBER);
 184         return 0;
 185     }
 186     if (!(flags & ENGINE_CMD_FLAG_NO_INPUT) &&
 187         !(flags & ENGINE_CMD_FLAG_NUMERIC) &&
 188         !(flags & ENGINE_CMD_FLAG_STRING))
 189         return 0;
 190     return 1;
 191 }
 192
 193 int ENGINE_ctrl_cmd(ENGINE *e, const char *cmd_name,
 194                     long i, void *p, void (*f) (void), int cmd_optional)
 195 {
 196     int num;
 197
 198     if (e == NULL || cmd_name == NULL) {
 199         ENGINEerr(ENGINE_F_ENGINE_CTRL_CMD, ERR_R_PASSED_NULL_PARAMETER);
 200         return 0;
 201     }
 202     if (e->ctrl == NULL
 203         || (num = ENGINE_ctrl(e, ENGINE_CTRL_GET_CMD_FROM_NAME,
 204                               0, (void *)cmd_name, NULL)) <= 0) {
 205         /*
 206          * If the command didn't *have* to be supported, we fake success.
 207          * This allows certain settings to be specified for multiple ENGINEs
 208          * and only require a change of ENGINE id (without having to
 209          * selectively apply settings). Eg. changing from a hardware device
 210          * back to the regular software ENGINE without editing the config
 211          * file, etc.
 212          */
 213         if (cmd_optional) {
 214             ERR_clear_error();
 215             return 1;
 216         }
 217         ENGINEerr(ENGINE_F_ENGINE_CTRL_CMD, ENGINE_R_INVALID_CMD_NAME);
 218         return 0;
 219     }
 220     /*
 221      * Force the result of the control command to 0 or 1, for the reasons
 222      * mentioned before.
 223      */
 224     if (ENGINE_ctrl(e, num, i, p, f) > 0)
 225         return 1;
 226     return 0;
 227 }
 228
 229 int ENGINE_ctrl_cmd_string(ENGINE *e, const char *cmd_name, const char *arg,
 230                            int cmd_optional)
 231 {
 232     int num, flags;
 233     long l;
 234     char *ptr;
 235
 236     if (e == NULL || cmd_name == NULL) {
 237         ENGINEerr(ENGINE_F_ENGINE_CTRL_CMD_STRING, ERR_R_PASSED_NULL_PARAMETER);
 238         return 0;
 239     }
 240     if (e->ctrl == NULL
 241         || (num = ENGINE_ctrl(e, ENGINE_CTRL_GET_CMD_FROM_NAME,
 242                               0, (void *)cmd_name, NULL)) <= 0) {
 243         /*
 244          * If the command didn't *have* to be supported, we fake success.
 245          * This allows certain settings to be specified for multiple ENGINEs
 246          * and only require a change of ENGINE id (without having to
 247          * selectively apply settings). Eg. changing from a hardware device
 248          * back to the regular software ENGINE without editing the config
 249          * file, etc.
 250          */
 251         if (cmd_optional) {
 252             ERR_clear_error();
 253             return 1;
 254         }
 255         ENGINEerr(ENGINE_F_ENGINE_CTRL_CMD_STRING, ENGINE_R_INVALID_CMD_NAME);
 256         return 0;
 257     }
 258     if (!ENGINE_cmd_is_executable(e, num)) {
 259         ENGINEerr(ENGINE_F_ENGINE_CTRL_CMD_STRING,
 260                   ENGINE_R_CMD_NOT_EXECUTABLE);
 261         return 0;
 262     }
 263
 264     flags = ENGINE_ctrl(e, ENGINE_CTRL_GET_CMD_FLAGS, num, NULL, NULL);
 265     if (flags < 0) {
 266         /*
 267          * Shouldn't happen, given that ENGINE_cmd_is_executable() returned
 268          * success.
 269          */
 270         ENGINEerr(ENGINE_F_ENGINE_CTRL_CMD_STRING,
 271                   ENGINE_R_INTERNAL_LIST_ERROR);
 272         return 0;
 273     }
 274     /*
 275      * If the command takes no input, there must be no input. And vice versa.
 276      */
 277     if (flags & ENGINE_CMD_FLAG_NO_INPUT) {
 278         if (arg != NULL) {
 279             ENGINEerr(ENGINE_F_ENGINE_CTRL_CMD_STRING,
 280                       ENGINE_R_COMMAND_TAKES_NO_INPUT);
 281             return 0;
 282         }
 283         /*
 284          * We deliberately force the result of ENGINE_ctrl() to 0 or 1 rather
 285          * than returning it as "return data". This is to ensure usage of
 286          * these commands is consistent across applications and that certain
 287          * applications don't understand it one way, and others another.
 288          */
 289         if (ENGINE_ctrl(e, num, 0, (void *)arg, NULL) > 0)
 290             return 1;
 291         return 0;
 292     }
 293     /* So, we require input */
 294     if (arg == NULL) {
 295         ENGINEerr(ENGINE_F_ENGINE_CTRL_CMD_STRING,
 296                   ENGINE_R_COMMAND_TAKES_INPUT);
 297         return 0;
 298     }
 299     /* If it takes string input, that's easy */
 300     if (flags & ENGINE_CMD_FLAG_STRING) {
 301         /* Same explanation as above */
 302         if (ENGINE_ctrl(e, num, 0, (void *)arg, NULL) > 0)
 303             return 1;
 304         return 0;
 305     }
 306     /*
 307      * If it doesn't take numeric either, then it is unsupported for use in a
 308      * config-setting situation, which is what this function is for. This
 309      * should never happen though, because ENGINE_cmd_is_executable() was
 310      * used.
 311      */
 312     if (!(flags & ENGINE_CMD_FLAG_NUMERIC)) {
 313         ENGINEerr(ENGINE_F_ENGINE_CTRL_CMD_STRING,
 314                   ENGINE_R_INTERNAL_LIST_ERROR);
 315         return 0;
 316     }
 317     l = strtol(arg, &ptr, 10);
 318     if ((arg == ptr) || (*ptr != '\0')) {
 319         ENGINEerr(ENGINE_F_ENGINE_CTRL_CMD_STRING,
 320                   ENGINE_R_ARGUMENT_IS_NOT_A_NUMBER);
 321         return 0;
 322     }
 323     /*
 324      * Force the result of the control command to 0 or 1, for the reasons
 325      * mentioned before.
 326      */
 327     if (ENGINE_ctrl(e, num, l, NULL, NULL) > 0)
 328         return 1;
 329     return 0;
 330 }