1 /* $OpenBSD: eng_ctrl.c,v 1.11 2017/01/29 17:49:23 beck Exp $ */
2 /* ====================================================================
3  * Copyright (c) 1999-2001 The OpenSSL Project.  All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  *
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer.
11  *
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in
14  *    the documentation and/or other materials provided with the
15  *    distribution.
16  *
17  * 3. All advertising materials mentioning features or use of this
18  *    software must display the following acknowledgment:
19  *    "This product includes software developed by the OpenSSL Project
20  *    for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"
21  *
22  * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
23  *    endorse or promote products derived from this software without
24  *    prior written permission. For written permission, please contact
25  *    licensing@OpenSSL.org.
26  *
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28  *    nor may "OpenSSL" appear in their names without prior written
29  *    permission of the OpenSSL Project.
30  *
31  * 6. Redistributions of any form whatsoever must retain the following
32  *    acknowledgment:
33  *    "This product includes software developed by the OpenSSL Project
34  *    for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"
35  *
36  * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
37  * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
38  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
39  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
40  * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
41  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
42  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
43  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
44  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
45  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
46  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
47  * OF THE POSSIBILITY OF SUCH DAMAGE.
48  * ====================================================================
49  *
50  * This product includes cryptographic software written by Eric Young
51  * (eay@cryptsoft.com).  This product includes software written by Tim
52  * Hudson (tjh@cryptsoft.com).
53  *
54  */
55 
56 #include <string.h>
57 
58 #include <openssl/err.h>
59 
60 #include "eng_int.h"
61 
62 /* When querying a ENGINE-specific control command's 'description', this string
63  * is used if the ENGINE_CMD_DEFN has cmd_desc set to NULL. */
64 static const char *int_no_description = "";
65 
66 /* These internal functions handle 'CMD'-related control commands when the
67  * ENGINE in question has asked us to take care of it (ie. the ENGINE did not
68  * set the ENGINE_FLAGS_MANUAL_CMD_CTRL flag. */
69 
70 static int
71 int_ctrl_cmd_is_null(const ENGINE_CMD_DEFN *defn)
72 {
73 	if ((defn->cmd_num == 0) || (defn->cmd_name == NULL))
74 		return 1;
75 	return 0;
76 }
77 
78 static int
79 int_ctrl_cmd_by_name(const ENGINE_CMD_DEFN *defn, const char *s)
80 {
81 	int idx = 0;
82 	while (!int_ctrl_cmd_is_null(defn) &&
83 	    (strcmp(defn->cmd_name, s) != 0)) {
84 		idx++;
85 		defn++;
86 	}
87 	if (int_ctrl_cmd_is_null(defn))
88 		/* The given name wasn't found */
89 		return -1;
90 	return idx;
91 }
92 
93 static int
94 int_ctrl_cmd_by_num(const ENGINE_CMD_DEFN *defn, unsigned int num)
95 {
96 	int idx = 0;
97 	/* NB: It is stipulated that 'cmd_defn' lists are ordered by cmd_num. So
98 	 * our searches don't need to take any longer than necessary. */
99 	while (!int_ctrl_cmd_is_null(defn) && (defn->cmd_num < num)) {
100 		idx++;
101 		defn++;
102 	}
103 	if (defn->cmd_num == num)
104 		return idx;
105 	/* The given cmd_num wasn't found */
106 	return -1;
107 }
108 
109 static int
110 int_ctrl_helper(ENGINE *e, int cmd, long i, void *p, void (*f)(void))
111 {
112 	int idx;
113 	int ret;
114 	char *s = (char *)p;
115 
116 	/* Take care of the easy one first (eg. it requires no searches) */
117 	if (cmd == ENGINE_CTRL_GET_FIRST_CMD_TYPE) {
118 		if ((e->cmd_defns == NULL) ||
119 		    int_ctrl_cmd_is_null(e->cmd_defns))
120 			return 0;
121 		return e->cmd_defns->cmd_num;
122 	}
123 	/* One or two commands require that "p" be a valid string buffer */
124 	if ((cmd == ENGINE_CTRL_GET_CMD_FROM_NAME) ||
125 	    (cmd == ENGINE_CTRL_GET_NAME_FROM_CMD) ||
126 	    (cmd == ENGINE_CTRL_GET_DESC_FROM_CMD)) {
127 		if (s == NULL) {
128 			ENGINEerror(ERR_R_PASSED_NULL_PARAMETER);
129 			return -1;
130 		}
131 	}
132 	/* Now handle cmd_name -> cmd_num conversion */
133 	if (cmd == ENGINE_CTRL_GET_CMD_FROM_NAME) {
134 		if ((e->cmd_defns == NULL) ||
135 		    ((idx = int_ctrl_cmd_by_name(e->cmd_defns, s)) < 0)) {
136 			ENGINEerror(ENGINE_R_INVALID_CMD_NAME);
137 			return -1;
138 		}
139 		return e->cmd_defns[idx].cmd_num;
140 	}
141 	/* For the rest of the commands, the 'long' argument must specify a
142 	 * valie command number - so we need to conduct a search. */
143 	if ((e->cmd_defns == NULL) ||
144 	    ((idx = int_ctrl_cmd_by_num(e->cmd_defns, (unsigned int)i)) < 0)) {
145 		ENGINEerror(ENGINE_R_INVALID_CMD_NUMBER);
146 		return -1;
147 	}
148 	/* Now the logic splits depending on command type */
149 	switch (cmd) {
150 	case ENGINE_CTRL_GET_NEXT_CMD_TYPE:
151 		idx++;
152 		if (int_ctrl_cmd_is_null(e->cmd_defns + idx))
153 			/* end-of-list */
154 			return 0;
155 		else
156 			return e->cmd_defns[idx].cmd_num;
157 	case ENGINE_CTRL_GET_NAME_LEN_FROM_CMD:
158 		return strlen(e->cmd_defns[idx].cmd_name);
159 	case ENGINE_CTRL_GET_NAME_FROM_CMD:
160 		ret = snprintf(s, strlen(e->cmd_defns[idx].cmd_name) + 1,
161 		    "%s", e->cmd_defns[idx].cmd_name);
162 		if (ret >= (strlen(e->cmd_defns[idx].cmd_name) + 1))
163 			ret = -1;
164 		return ret;
165 	case ENGINE_CTRL_GET_DESC_LEN_FROM_CMD:
166 		if (e->cmd_defns[idx].cmd_desc)
167 			return strlen(e->cmd_defns[idx].cmd_desc);
168 		return strlen(int_no_description);
169 	case ENGINE_CTRL_GET_DESC_FROM_CMD:
170 		if (e->cmd_defns[idx].cmd_desc) {
171 			ret = snprintf(s,
172 			    strlen(e->cmd_defns[idx].cmd_desc) + 1,
173 			    "%s", e->cmd_defns[idx].cmd_desc);
174 			if (ret >= strlen(e->cmd_defns[idx].cmd_desc) + 1)
175 				ret = -1;
176 			return ret;
177 		}
178 		ret = snprintf(s, strlen(int_no_description) + 1, "%s",
179 		    int_no_description);
180 		if (ret >= strlen(int_no_description) + 1)
181 			ret = -1;
182 		return ret;
183 	case ENGINE_CTRL_GET_CMD_FLAGS:
184 		return e->cmd_defns[idx].cmd_flags;
185 	}
186 
187 	/* Shouldn't really be here ... */
188 	ENGINEerror(ENGINE_R_INTERNAL_LIST_ERROR);
189 	return -1;
190 }
191 
192 int
193 ENGINE_ctrl(ENGINE *e, int cmd, long i, void *p, void (*f)(void))
194 {
195 	int ctrl_exists, ref_exists;
196 
197 	if (e == NULL) {
198 		ENGINEerror(ERR_R_PASSED_NULL_PARAMETER);
199 		return 0;
200 	}
201 	CRYPTO_w_lock(CRYPTO_LOCK_ENGINE);
202 	ref_exists = ((e->struct_ref > 0) ? 1 : 0);
203 	CRYPTO_w_unlock(CRYPTO_LOCK_ENGINE);
204 	ctrl_exists = ((e->ctrl == NULL) ? 0 : 1);
205 	if (!ref_exists) {
206 		ENGINEerror(ENGINE_R_NO_REFERENCE);
207 		return 0;
208 	}
209 	/* Intercept any "root-level" commands before trying to hand them on to
210 	 * ctrl() handlers. */
211 	switch (cmd) {
212 	case ENGINE_CTRL_HAS_CTRL_FUNCTION:
213 		return ctrl_exists;
214 	case ENGINE_CTRL_GET_FIRST_CMD_TYPE:
215 	case ENGINE_CTRL_GET_NEXT_CMD_TYPE:
216 	case ENGINE_CTRL_GET_CMD_FROM_NAME:
217 	case ENGINE_CTRL_GET_NAME_LEN_FROM_CMD:
218 	case ENGINE_CTRL_GET_NAME_FROM_CMD:
219 	case ENGINE_CTRL_GET_DESC_LEN_FROM_CMD:
220 	case ENGINE_CTRL_GET_DESC_FROM_CMD:
221 	case ENGINE_CTRL_GET_CMD_FLAGS:
222 		if (ctrl_exists && !(e->flags & ENGINE_FLAGS_MANUAL_CMD_CTRL))
223 			return int_ctrl_helper(e, cmd, i, p, f);
224 		if (!ctrl_exists) {
225 			ENGINEerror(ENGINE_R_NO_CONTROL_FUNCTION);
226 			/* For these cmd-related functions, failure is indicated
227 			 * by a -1 return value (because 0 is used as a valid
228 			 * return in some places). */
229 			return -1;
230 		}
231 	default:
232 		break;
233 	}
234 	/* Anything else requires a ctrl() handler to exist. */
235 	if (!ctrl_exists) {
236 		ENGINEerror(ENGINE_R_NO_CONTROL_FUNCTION);
237 		return 0;
238 	}
239 	return e->ctrl(e, cmd, i, p, f);
240 }
241 
242 int
243 ENGINE_cmd_is_executable(ENGINE *e, int cmd)
244 {
245 	int flags;
246 
247 	if ((flags = ENGINE_ctrl(e, ENGINE_CTRL_GET_CMD_FLAGS, cmd,
248 	    NULL, NULL)) < 0) {
249 		ENGINEerror(ENGINE_R_INVALID_CMD_NUMBER);
250 		return 0;
251 	}
252 	if (!(flags & ENGINE_CMD_FLAG_NO_INPUT) &&
253 	    !(flags & ENGINE_CMD_FLAG_NUMERIC) &&
254 	    !(flags & ENGINE_CMD_FLAG_STRING))
255 		return 0;
256 	return 1;
257 }
258 
259 int
260 ENGINE_ctrl_cmd(ENGINE *e, const char *cmd_name, long i, void *p,
261     void (*f)(void), int cmd_optional)
262 {
263 	int num;
264 
265 	if ((e == NULL) || (cmd_name == NULL)) {
266 		ENGINEerror(ERR_R_PASSED_NULL_PARAMETER);
267 		return 0;
268 	}
269 	if ((e->ctrl == NULL) ||
270 	    ((num = ENGINE_ctrl(e, ENGINE_CTRL_GET_CMD_FROM_NAME,
271 	    0, (void *)cmd_name, NULL)) <= 0)) {
272 		/* If the command didn't *have* to be supported, we fake
273 		 * success. This allows certain settings to be specified for
274 		 * multiple ENGINEs and only require a change of ENGINE id
275 		 * (without having to selectively apply settings). Eg. changing
276 		 * from a hardware device back to the regular software ENGINE
277 		 * without editing the config file, etc. */
278 		if (cmd_optional) {
279 			ERR_clear_error();
280 			return 1;
281 		}
282 		ENGINEerror(ENGINE_R_INVALID_CMD_NAME);
283 		return 0;
284 	}
285 
286 	/* Force the result of the control command to 0 or 1, for the reasons
287 	 * mentioned before. */
288 	if (ENGINE_ctrl(e, num, i, p, f) > 0)
289 		return 1;
290 
291 	return 0;
292 }
293 
294 int
295 ENGINE_ctrl_cmd_string(ENGINE *e, const char *cmd_name, const char *arg,
296     int cmd_optional)
297 {
298 	int num, flags;
299 	long l;
300 	char *ptr;
301 
302 	if ((e == NULL) || (cmd_name == NULL)) {
303 		ENGINEerror(ERR_R_PASSED_NULL_PARAMETER);
304 		return 0;
305 	}
306 	if ((e->ctrl == NULL) ||
307 	    ((num = ENGINE_ctrl(e, ENGINE_CTRL_GET_CMD_FROM_NAME, 0,
308 	    (void *)cmd_name, NULL)) <= 0)) {
309 		/* If the command didn't *have* to be supported, we fake
310 		 * success. This allows certain settings to be specified for
311 		 * multiple ENGINEs and only require a change of ENGINE id
312 		 * (without having to selectively apply settings). Eg. changing
313 		 * from a hardware device back to the regular software ENGINE
314 		 * without editing the config file, etc. */
315 		if (cmd_optional) {
316 			ERR_clear_error();
317 			return 1;
318 		}
319 		ENGINEerror(ENGINE_R_INVALID_CMD_NAME);
320 		return 0;
321 	}
322 	if (!ENGINE_cmd_is_executable(e, num)) {
323 		ENGINEerror(ENGINE_R_CMD_NOT_EXECUTABLE);
324 		return 0;
325 	}
326 	if ((flags = ENGINE_ctrl(e, ENGINE_CTRL_GET_CMD_FLAGS, num,
327 	    NULL, NULL)) < 0) {
328 		/* Shouldn't happen, given that ENGINE_cmd_is_executable()
329 		 * returned success. */
330 		ENGINEerror(ENGINE_R_INTERNAL_LIST_ERROR);
331 		return 0;
332 	}
333 	/* If the command takes no input, there must be no input. And vice
334 	 * versa. */
335 	if (flags & ENGINE_CMD_FLAG_NO_INPUT) {
336 		if (arg != NULL) {
337 			ENGINEerror(ENGINE_R_COMMAND_TAKES_NO_INPUT);
338 			return 0;
339 		}
340 		/* We deliberately force the result of ENGINE_ctrl() to 0 or 1
341 		 * rather than returning it as "return data". This is to ensure
342 		 * usage of these commands is consistent across applications and
343 		 * that certain applications don't understand it one way, and
344 		 * others another. */
345 		if (ENGINE_ctrl(e, num, 0, (void *)arg, NULL) > 0)
346 			return 1;
347 		return 0;
348 	}
349 	/* So, we require input */
350 	if (arg == NULL) {
351 		ENGINEerror(ENGINE_R_COMMAND_TAKES_INPUT);
352 		return 0;
353 	}
354 	/* If it takes string input, that's easy */
355 	if (flags & ENGINE_CMD_FLAG_STRING) {
356 		/* Same explanation as above */
357 		if (ENGINE_ctrl(e, num, 0, (void *)arg, NULL) > 0)
358 			return 1;
359 		return 0;
360 	}
361 	/* If it doesn't take numeric either, then it is unsupported for use in
362 	 * a config-setting situation, which is what this function is for. This
363 	 * should never happen though, because ENGINE_cmd_is_executable() was
364 	 * used. */
365 	if (!(flags & ENGINE_CMD_FLAG_NUMERIC)) {
366 		ENGINEerror(ENGINE_R_INTERNAL_LIST_ERROR);
367 		return 0;
368 	}
369 	l = strtol(arg, &ptr, 10);
370 	if ((arg == ptr) || (*ptr != '\0')) {
371 		ENGINEerror(ENGINE_R_ARGUMENT_IS_NOT_A_NUMBER);
372 		return 0;
373 	}
374 	/* Force the result of the control command to 0 or 1, for the reasons
375 	 * mentioned before. */
376 	if (ENGINE_ctrl(e, num, l, NULL, NULL) > 0)
377 		return 1;
378 	return 0;
379 }
380