1/*
2 * Copyright 2001-2021 The OpenSSL Project Authors. All Rights Reserved.
3 *
4 * Licensed under the Apache License 2.0 (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/* We need to use some engine deprecated APIs */
11#define OPENSSL_SUPPRESS_DEPRECATED
12
13#include "eng_local.h"
14
15/*
16 * When querying a ENGINE-specific control command's 'description', this
17 * string is used if the ENGINE_CMD_DEFN has cmd_desc set to NULL.
18 */
19static const char *int_no_description = "";
20
21/*
22 * These internal functions handle 'CMD'-related control commands when the
23 * ENGINE in question has asked us to take care of it (ie. the ENGINE did not
24 * set the ENGINE_FLAGS_MANUAL_CMD_CTRL flag.
25 */
26
27static int int_ctrl_cmd_is_null(const ENGINE_CMD_DEFN *defn)
28{
29    if ((defn->cmd_num == 0) || (defn->cmd_name == NULL))
30        return 1;
31    return 0;
32}
33
34static int int_ctrl_cmd_by_name(const ENGINE_CMD_DEFN *defn, const char *s)
35{
36    int idx = 0;
37    while (!int_ctrl_cmd_is_null(defn) && (strcmp(defn->cmd_name, s) != 0)) {
38        idx++;
39        defn++;
40    }
41    if (int_ctrl_cmd_is_null(defn))
42        /* The given name wasn't found */
43        return -1;
44    return idx;
45}
46
47static int int_ctrl_cmd_by_num(const ENGINE_CMD_DEFN *defn, unsigned int num)
48{
49    int idx = 0;
50    /*
51     * NB: It is stipulated that 'cmd_defn' lists are ordered by cmd_num. So
52     * our searches don't need to take any longer than necessary.
53     */
54    while (!int_ctrl_cmd_is_null(defn) && (defn->cmd_num < num)) {
55        idx++;
56        defn++;
57    }
58    if (defn->cmd_num == num)
59        return idx;
60    /* The given cmd_num wasn't found */
61    return -1;
62}
63
64static int int_ctrl_helper(ENGINE *e, int cmd, long i, void *p,
65                           void (*f) (void))
66{
67    int idx;
68    char *s = (char *)p;
69    const ENGINE_CMD_DEFN *cdp;
70
71    /* Take care of the easy one first (eg. it requires no searches) */
72    if (cmd == ENGINE_CTRL_GET_FIRST_CMD_TYPE) {
73        if ((e->cmd_defns == NULL) || int_ctrl_cmd_is_null(e->cmd_defns))
74            return 0;
75        return e->cmd_defns->cmd_num;
76    }
77    /* One or two commands require that "p" be a valid string buffer */
78    if ((cmd == ENGINE_CTRL_GET_CMD_FROM_NAME) ||
79        (cmd == ENGINE_CTRL_GET_NAME_FROM_CMD) ||
80        (cmd == ENGINE_CTRL_GET_DESC_FROM_CMD)) {
81        if (s == NULL) {
82            ERR_raise(ERR_LIB_ENGINE, ERR_R_PASSED_NULL_PARAMETER);
83            return -1;
84        }
85    }
86    /* Now handle cmd_name -> cmd_num conversion */
87    if (cmd == ENGINE_CTRL_GET_CMD_FROM_NAME) {
88        if ((e->cmd_defns == NULL)
89            || ((idx = int_ctrl_cmd_by_name(e->cmd_defns, s)) < 0)) {
90            ERR_raise(ERR_LIB_ENGINE, ENGINE_R_INVALID_CMD_NAME);
91            return -1;
92        }
93        return e->cmd_defns[idx].cmd_num;
94    }
95    /*
96     * For the rest of the commands, the 'long' argument must specify a valid
97     * command number - so we need to conduct a search.
98     */
99    if ((e->cmd_defns == NULL)
100        || ((idx = int_ctrl_cmd_by_num(e->cmd_defns, (unsigned int)i)) < 0)) {
101        ERR_raise(ERR_LIB_ENGINE, ENGINE_R_INVALID_CMD_NUMBER);
102        return -1;
103    }
104    /* Now the logic splits depending on command type */
105    cdp = &e->cmd_defns[idx];
106    switch (cmd) {
107    case ENGINE_CTRL_GET_NEXT_CMD_TYPE:
108        cdp++;
109        return int_ctrl_cmd_is_null(cdp) ? 0 : cdp->cmd_num;
110    case ENGINE_CTRL_GET_NAME_LEN_FROM_CMD:
111        return strlen(cdp->cmd_name);
112    case ENGINE_CTRL_GET_NAME_FROM_CMD:
113        return strlen(strcpy(s, cdp->cmd_name));
114    case ENGINE_CTRL_GET_DESC_LEN_FROM_CMD:
115        return strlen(cdp->cmd_desc == NULL ? int_no_description
116                                            : cdp->cmd_desc);
117    case ENGINE_CTRL_GET_DESC_FROM_CMD:
118        return strlen(strcpy(s, cdp->cmd_desc == NULL ? int_no_description
119                                                      : cdp->cmd_desc));
120    case ENGINE_CTRL_GET_CMD_FLAGS:
121        return cdp->cmd_flags;
122    }
123    /* Shouldn't really be here ... */
124    ERR_raise(ERR_LIB_ENGINE, ENGINE_R_INTERNAL_LIST_ERROR);
125    return -1;
126}
127
128int ENGINE_ctrl(ENGINE *e, int cmd, long i, void *p, void (*f) (void))
129{
130    int ctrl_exists, ref_exists;
131    if (e == NULL) {
132        ERR_raise(ERR_LIB_ENGINE, ERR_R_PASSED_NULL_PARAMETER);
133        return 0;
134    }
135    if (!CRYPTO_THREAD_write_lock(global_engine_lock))
136        return 0;
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        ERR_raise(ERR_LIB_ENGINE, 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            ERR_raise(ERR_LIB_ENGINE, 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        ERR_raise(ERR_LIB_ENGINE, ENGINE_R_NO_CONTROL_FUNCTION);
176        return 0;
177    }
178    return e->ctrl(e, cmd, i, p, f);
179}
180
181int 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        ERR_raise(ERR_LIB_ENGINE, ENGINE_R_INVALID_CMD_NUMBER);
187        return 0;
188    }
189    if (!(flags & ENGINE_CMD_FLAG_NO_INPUT) &&
190        !(flags & ENGINE_CMD_FLAG_NUMERIC) &&
191        !(flags & ENGINE_CMD_FLAG_STRING))
192        return 0;
193    return 1;
194}
195
196int ENGINE_ctrl_cmd(ENGINE *e, const char *cmd_name,
197                    long i, void *p, void (*f) (void), int cmd_optional)
198{
199    int num;
200
201    if (e == NULL || cmd_name == NULL) {
202        ERR_raise(ERR_LIB_ENGINE, ERR_R_PASSED_NULL_PARAMETER);
203        return 0;
204    }
205    if (e->ctrl == NULL
206        || (num = ENGINE_ctrl(e, ENGINE_CTRL_GET_CMD_FROM_NAME,
207                              0, (void *)cmd_name, NULL)) <= 0) {
208        /*
209         * If the command didn't *have* to be supported, we fake success.
210         * This allows certain settings to be specified for multiple ENGINEs
211         * and only require a change of ENGINE id (without having to
212         * selectively apply settings). Eg. changing from a hardware device
213         * back to the regular software ENGINE without editing the config
214         * file, etc.
215         */
216        if (cmd_optional) {
217            ERR_clear_error();
218            return 1;
219        }
220        ERR_raise(ERR_LIB_ENGINE, ENGINE_R_INVALID_CMD_NAME);
221        return 0;
222    }
223    /*
224     * Force the result of the control command to 0 or 1, for the reasons
225     * mentioned before.
226     */
227    if (ENGINE_ctrl(e, num, i, p, f) > 0)
228        return 1;
229    return 0;
230}
231
232int ENGINE_ctrl_cmd_string(ENGINE *e, const char *cmd_name, const char *arg,
233                           int cmd_optional)
234{
235    int num, flags;
236    long l;
237    char *ptr;
238
239    if (e == NULL || cmd_name == NULL) {
240        ERR_raise(ERR_LIB_ENGINE, ERR_R_PASSED_NULL_PARAMETER);
241        return 0;
242    }
243    if (e->ctrl == NULL
244        || (num = ENGINE_ctrl(e, ENGINE_CTRL_GET_CMD_FROM_NAME,
245                              0, (void *)cmd_name, NULL)) <= 0) {
246        /*
247         * If the command didn't *have* to be supported, we fake success.
248         * This allows certain settings to be specified for multiple ENGINEs
249         * and only require a change of ENGINE id (without having to
250         * selectively apply settings). Eg. changing from a hardware device
251         * back to the regular software ENGINE without editing the config
252         * file, etc.
253         */
254        if (cmd_optional) {
255            ERR_clear_error();
256            return 1;
257        }
258        ERR_raise(ERR_LIB_ENGINE, ENGINE_R_INVALID_CMD_NAME);
259        return 0;
260    }
261    if (!ENGINE_cmd_is_executable(e, num)) {
262        ERR_raise(ERR_LIB_ENGINE, ENGINE_R_CMD_NOT_EXECUTABLE);
263        return 0;
264    }
265
266    flags = ENGINE_ctrl(e, ENGINE_CTRL_GET_CMD_FLAGS, num, NULL, NULL);
267    if (flags < 0) {
268        /*
269         * Shouldn't happen, given that ENGINE_cmd_is_executable() returned
270         * success.
271         */
272        ERR_raise(ERR_LIB_ENGINE, ENGINE_R_INTERNAL_LIST_ERROR);
273        return 0;
274    }
275    /*
276     * If the command takes no input, there must be no input. And vice versa.
277     */
278    if (flags & ENGINE_CMD_FLAG_NO_INPUT) {
279        if (arg != NULL) {
280            ERR_raise(ERR_LIB_ENGINE, 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        ERR_raise(ERR_LIB_ENGINE, ENGINE_R_COMMAND_TAKES_INPUT);
296        return 0;
297    }
298    /* If it takes string input, that's easy */
299    if (flags & ENGINE_CMD_FLAG_STRING) {
300        /* Same explanation as above */
301        if (ENGINE_ctrl(e, num, 0, (void *)arg, NULL) > 0)
302            return 1;
303        return 0;
304    }
305    /*
306     * If it doesn't take numeric either, then it is unsupported for use in a
307     * config-setting situation, which is what this function is for. This
308     * should never happen though, because ENGINE_cmd_is_executable() was
309     * used.
310     */
311    if (!(flags & ENGINE_CMD_FLAG_NUMERIC)) {
312        ERR_raise(ERR_LIB_ENGINE, ENGINE_R_INTERNAL_LIST_ERROR);
313        return 0;
314    }
315    l = strtol(arg, &ptr, 10);
316    if ((arg == ptr) || (*ptr != '\0')) {
317        ERR_raise(ERR_LIB_ENGINE, ENGINE_R_ARGUMENT_IS_NOT_A_NUMBER);
318        return 0;
319    }
320    /*
321     * Force the result of the control command to 0 or 1, for the reasons
322     * mentioned before.
323     */
324    if (ENGINE_ctrl(e, num, l, NULL, NULL) > 0)
325        return 1;
326    return 0;
327}
328