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_local.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 */
16static 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
24static 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
31static 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
44static 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
61static 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
125int 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
177int 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
193int 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
229int 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}
331