1 /* $OpenBSD: eng_ctrl.c,v 1.9 2014/07/10 13:58:22 jsing 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.
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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 			ENGINEerr(ENGINE_F_INT_CTRL_HELPER,
129 			    ERR_R_PASSED_NULL_PARAMETER);
130 			return -1;
131 		}
132 	}
133 	/* Now handle cmd_name -> cmd_num conversion */
134 	if (cmd == ENGINE_CTRL_GET_CMD_FROM_NAME) {
135 		if ((e->cmd_defns == NULL) ||
136 		    ((idx = int_ctrl_cmd_by_name(e->cmd_defns, s)) < 0)) {
137 			ENGINEerr(ENGINE_F_INT_CTRL_HELPER,
138 			    ENGINE_R_INVALID_CMD_NAME);
139 			return -1;
140 		}
141 		return e->cmd_defns[idx].cmd_num;
142 	}
143 	/* For the rest of the commands, the 'long' argument must specify a
144 	 * valie command number - so we need to conduct a search. */
145 	if ((e->cmd_defns == NULL) ||
146 	    ((idx = int_ctrl_cmd_by_num(e->cmd_defns, (unsigned int)i)) < 0)) {
147 		ENGINEerr(ENGINE_F_INT_CTRL_HELPER,
148 		    ENGINE_R_INVALID_CMD_NUMBER);
149 		return -1;
150 	}
151 	/* Now the logic splits depending on command type */
152 	switch (cmd) {
153 	case ENGINE_CTRL_GET_NEXT_CMD_TYPE:
154 		idx++;
155 		if (int_ctrl_cmd_is_null(e->cmd_defns + idx))
156 			/* end-of-list */
157 			return 0;
158 		else
159 			return e->cmd_defns[idx].cmd_num;
160 	case ENGINE_CTRL_GET_NAME_LEN_FROM_CMD:
161 		return strlen(e->cmd_defns[idx].cmd_name);
162 	case ENGINE_CTRL_GET_NAME_FROM_CMD:
163 		ret = snprintf(s, strlen(e->cmd_defns[idx].cmd_name) + 1,
164 		    "%s", e->cmd_defns[idx].cmd_name);
165 		if (ret >= (strlen(e->cmd_defns[idx].cmd_name) + 1))
166 			ret = -1;
167 		return ret;
168 	case ENGINE_CTRL_GET_DESC_LEN_FROM_CMD:
169 		if (e->cmd_defns[idx].cmd_desc)
170 			return strlen(e->cmd_defns[idx].cmd_desc);
171 		return strlen(int_no_description);
172 	case ENGINE_CTRL_GET_DESC_FROM_CMD:
173 		if (e->cmd_defns[idx].cmd_desc) {
174 			ret = snprintf(s,
175 			    strlen(e->cmd_defns[idx].cmd_desc) + 1,
176 			    "%s", e->cmd_defns[idx].cmd_desc);
177 			if (ret >= strlen(e->cmd_defns[idx].cmd_desc) + 1)
178 				ret = -1;
179 			return ret;
180 		}
181 		ret = snprintf(s, strlen(int_no_description) + 1, "%s",
182 		    int_no_description);
183 		if (ret >= strlen(int_no_description) + 1)
184 			ret = -1;
185 		return ret;
186 	case ENGINE_CTRL_GET_CMD_FLAGS:
187 		return e->cmd_defns[idx].cmd_flags;
188 	}
189 
190 	/* Shouldn't really be here ... */
191 	ENGINEerr(ENGINE_F_INT_CTRL_HELPER, ENGINE_R_INTERNAL_LIST_ERROR);
192 	return -1;
193 }
194 
195 int
196 ENGINE_ctrl(ENGINE *e, int cmd, long i, void *p, void (*f)(void))
197 {
198 	int ctrl_exists, ref_exists;
199 
200 	if (e == NULL) {
201 		ENGINEerr(ENGINE_F_ENGINE_CTRL, ERR_R_PASSED_NULL_PARAMETER);
202 		return 0;
203 	}
204 	CRYPTO_w_lock(CRYPTO_LOCK_ENGINE);
205 	ref_exists = ((e->struct_ref > 0) ? 1 : 0);
206 	CRYPTO_w_unlock(CRYPTO_LOCK_ENGINE);
207 	ctrl_exists = ((e->ctrl == NULL) ? 0 : 1);
208 	if (!ref_exists) {
209 		ENGINEerr(ENGINE_F_ENGINE_CTRL, ENGINE_R_NO_REFERENCE);
210 		return 0;
211 	}
212 	/* Intercept any "root-level" commands before trying to hand them on to
213 	 * ctrl() handlers. */
214 	switch (cmd) {
215 	case ENGINE_CTRL_HAS_CTRL_FUNCTION:
216 		return ctrl_exists;
217 	case ENGINE_CTRL_GET_FIRST_CMD_TYPE:
218 	case ENGINE_CTRL_GET_NEXT_CMD_TYPE:
219 	case ENGINE_CTRL_GET_CMD_FROM_NAME:
220 	case ENGINE_CTRL_GET_NAME_LEN_FROM_CMD:
221 	case ENGINE_CTRL_GET_NAME_FROM_CMD:
222 	case ENGINE_CTRL_GET_DESC_LEN_FROM_CMD:
223 	case ENGINE_CTRL_GET_DESC_FROM_CMD:
224 	case ENGINE_CTRL_GET_CMD_FLAGS:
225 		if (ctrl_exists && !(e->flags & ENGINE_FLAGS_MANUAL_CMD_CTRL))
226 			return int_ctrl_helper(e, cmd, i, p, f);
227 		if (!ctrl_exists) {
228 			ENGINEerr(ENGINE_F_ENGINE_CTRL,
229 			    ENGINE_R_NO_CONTROL_FUNCTION);
230 			/* For these cmd-related functions, failure is indicated
231 			 * by a -1 return value (because 0 is used as a valid
232 			 * return in some places). */
233 			return -1;
234 		}
235 	default:
236 		break;
237 	}
238 	/* Anything else requires a ctrl() handler to exist. */
239 	if (!ctrl_exists) {
240 		ENGINEerr(ENGINE_F_ENGINE_CTRL, ENGINE_R_NO_CONTROL_FUNCTION);
241 		return 0;
242 	}
243 	return e->ctrl(e, cmd, i, p, f);
244 }
245 
246 int
247 ENGINE_cmd_is_executable(ENGINE *e, int cmd)
248 {
249 	int flags;
250 
251 	if ((flags = ENGINE_ctrl(e, ENGINE_CTRL_GET_CMD_FLAGS, cmd,
252 	    NULL, NULL)) < 0) {
253 		ENGINEerr(ENGINE_F_ENGINE_CMD_IS_EXECUTABLE,
254 		    ENGINE_R_INVALID_CMD_NUMBER);
255 		return 0;
256 	}
257 	if (!(flags & ENGINE_CMD_FLAG_NO_INPUT) &&
258 	    !(flags & ENGINE_CMD_FLAG_NUMERIC) &&
259 	    !(flags & ENGINE_CMD_FLAG_STRING))
260 		return 0;
261 	return 1;
262 }
263 
264 int
265 ENGINE_ctrl_cmd(ENGINE *e, const char *cmd_name, long i, void *p,
266     void (*f)(void), int cmd_optional)
267 {
268 	int num;
269 
270 	if ((e == NULL) || (cmd_name == NULL)) {
271 		ENGINEerr(ENGINE_F_ENGINE_CTRL_CMD,
272 		    ERR_R_PASSED_NULL_PARAMETER);
273 		return 0;
274 	}
275 	if ((e->ctrl == NULL) ||
276 	    ((num = ENGINE_ctrl(e, ENGINE_CTRL_GET_CMD_FROM_NAME,
277 	    0, (void *)cmd_name, NULL)) <= 0)) {
278 		/* If the command didn't *have* to be supported, we fake
279 		 * success. This allows certain settings to be specified for
280 		 * multiple ENGINEs and only require a change of ENGINE id
281 		 * (without having to selectively apply settings). Eg. changing
282 		 * from a hardware device back to the regular software ENGINE
283 		 * without editing the config file, etc. */
284 		if (cmd_optional) {
285 			ERR_clear_error();
286 			return 1;
287 		}
288 		ENGINEerr(ENGINE_F_ENGINE_CTRL_CMD, ENGINE_R_INVALID_CMD_NAME);
289 		return 0;
290 	}
291 
292 	/* Force the result of the control command to 0 or 1, for the reasons
293 	 * mentioned before. */
294 	if (ENGINE_ctrl(e, num, i, p, f) > 0)
295 		return 1;
296 
297 	return 0;
298 }
299 
300 int
301 ENGINE_ctrl_cmd_string(ENGINE *e, const char *cmd_name, const char *arg,
302     int cmd_optional)
303 {
304 	int num, flags;
305 	long l;
306 	char *ptr;
307 
308 	if ((e == NULL) || (cmd_name == NULL)) {
309 		ENGINEerr(ENGINE_F_ENGINE_CTRL_CMD_STRING,
310 		    ERR_R_PASSED_NULL_PARAMETER);
311 		return 0;
312 	}
313 	if ((e->ctrl == NULL) ||
314 	    ((num = ENGINE_ctrl(e, ENGINE_CTRL_GET_CMD_FROM_NAME, 0,
315 	    (void *)cmd_name, NULL)) <= 0)) {
316 		/* If the command didn't *have* to be supported, we fake
317 		 * success. This allows certain settings to be specified for
318 		 * multiple ENGINEs and only require a change of ENGINE id
319 		 * (without having to selectively apply settings). Eg. changing
320 		 * from a hardware device back to the regular software ENGINE
321 		 * without editing the config file, etc. */
322 		if (cmd_optional) {
323 			ERR_clear_error();
324 			return 1;
325 		}
326 		ENGINEerr(ENGINE_F_ENGINE_CTRL_CMD_STRING,
327 		    ENGINE_R_INVALID_CMD_NAME);
328 		return 0;
329 	}
330 	if (!ENGINE_cmd_is_executable(e, num)) {
331 		ENGINEerr(ENGINE_F_ENGINE_CTRL_CMD_STRING,
332 		    ENGINE_R_CMD_NOT_EXECUTABLE);
333 		return 0;
334 	}
335 	if ((flags = ENGINE_ctrl(e, ENGINE_CTRL_GET_CMD_FLAGS, num,
336 	    NULL, NULL)) < 0) {
337 		/* Shouldn't happen, given that ENGINE_cmd_is_executable()
338 		 * returned success. */
339 		ENGINEerr(ENGINE_F_ENGINE_CTRL_CMD_STRING,
340 		    ENGINE_R_INTERNAL_LIST_ERROR);
341 		return 0;
342 	}
343 	/* If the command takes no input, there must be no input. And vice
344 	 * versa. */
345 	if (flags & ENGINE_CMD_FLAG_NO_INPUT) {
346 		if (arg != NULL) {
347 			ENGINEerr(ENGINE_F_ENGINE_CTRL_CMD_STRING,
348 			    ENGINE_R_COMMAND_TAKES_NO_INPUT);
349 			return 0;
350 		}
351 		/* We deliberately force the result of ENGINE_ctrl() to 0 or 1
352 		 * rather than returning it as "return data". This is to ensure
353 		 * usage of these commands is consistent across applications and
354 		 * that certain applications don't understand it one way, and
355 		 * others another. */
356 		if (ENGINE_ctrl(e, num, 0, (void *)arg, NULL) > 0)
357 			return 1;
358 		return 0;
359 	}
360 	/* So, we require input */
361 	if (arg == NULL) {
362 		ENGINEerr(ENGINE_F_ENGINE_CTRL_CMD_STRING,
363 		    ENGINE_R_COMMAND_TAKES_INPUT);
364 		return 0;
365 	}
366 	/* If it takes string input, that's easy */
367 	if (flags & ENGINE_CMD_FLAG_STRING) {
368 		/* Same explanation as above */
369 		if (ENGINE_ctrl(e, num, 0, (void *)arg, NULL) > 0)
370 			return 1;
371 		return 0;
372 	}
373 	/* If it doesn't take numeric either, then it is unsupported for use in
374 	 * a config-setting situation, which is what this function is for. This
375 	 * should never happen though, because ENGINE_cmd_is_executable() was
376 	 * used. */
377 	if (!(flags & ENGINE_CMD_FLAG_NUMERIC)) {
378 		ENGINEerr(ENGINE_F_ENGINE_CTRL_CMD_STRING,
379 		    ENGINE_R_INTERNAL_LIST_ERROR);
380 		return 0;
381 	}
382 	l = strtol(arg, &ptr, 10);
383 	if ((arg == ptr) || (*ptr != '\0')) {
384 		ENGINEerr(ENGINE_F_ENGINE_CTRL_CMD_STRING,
385 		    ENGINE_R_ARGUMENT_IS_NOT_A_NUMBER);
386 		return 0;
387 	}
388 	/* Force the result of the control command to 0 or 1, for the reasons
389 	 * mentioned before. */
390 	if (ENGINE_ctrl(e, num, l, NULL, NULL) > 0)
391 		return 1;
392 	return 0;
393 }
394