Fix some style issues...
[openssl.git] / 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     /* Take care of the easy one first (eg. it requires no searches) */
67     if (cmd == ENGINE_CTRL_GET_FIRST_CMD_TYPE) {
68         if ((e->cmd_defns == NULL) || int_ctrl_cmd_is_null(e->cmd_defns))
69             return 0;
70         return e->cmd_defns->cmd_num;
71     }
72     /* One or two commands require that "p" be a valid string buffer */
73     if ((cmd == ENGINE_CTRL_GET_CMD_FROM_NAME) ||
74         (cmd == ENGINE_CTRL_GET_NAME_FROM_CMD) ||
75         (cmd == ENGINE_CTRL_GET_DESC_FROM_CMD)) {
76         if (s == NULL) {
77             ENGINEerr(ENGINE_F_INT_CTRL_HELPER, ERR_R_PASSED_NULL_PARAMETER);
78             return -1;
79         }
80     }
81     /* Now handle cmd_name -> cmd_num conversion */
82     if (cmd == ENGINE_CTRL_GET_CMD_FROM_NAME) {
83         if ((e->cmd_defns == NULL)
84             || ((idx = int_ctrl_cmd_by_name(e->cmd_defns, s)) < 0)) {
85             ENGINEerr(ENGINE_F_INT_CTRL_HELPER, ENGINE_R_INVALID_CMD_NAME);
86             return -1;
87         }
88         return e->cmd_defns[idx].cmd_num;
89     }
90     /*
91      * For the rest of the commands, the 'long' argument must specify a valid
92      * command number - so we need to conduct a search.
93      */
94     if ((e->cmd_defns == NULL) || ((idx = int_ctrl_cmd_by_num(e->cmd_defns,
95                                                               (unsigned int)
96                                                               i)) < 0)) {
97         ENGINEerr(ENGINE_F_INT_CTRL_HELPER, ENGINE_R_INVALID_CMD_NUMBER);
98         return -1;
99     }
100     /* Now the logic splits depending on command type */
101     switch (cmd) {
102     case ENGINE_CTRL_GET_NEXT_CMD_TYPE:
103         idx++;
104         if (int_ctrl_cmd_is_null(e->cmd_defns + idx))
105             /* end-of-list */
106             return 0;
107         else
108             return e->cmd_defns[idx].cmd_num;
109     case ENGINE_CTRL_GET_NAME_LEN_FROM_CMD:
110         return strlen(e->cmd_defns[idx].cmd_name);
111     case ENGINE_CTRL_GET_NAME_FROM_CMD:
112         return BIO_snprintf(s, strlen(e->cmd_defns[idx].cmd_name) + 1,
113                             "%s", e->cmd_defns[idx].cmd_name);
114     case ENGINE_CTRL_GET_DESC_LEN_FROM_CMD:
115         if (e->cmd_defns[idx].cmd_desc)
116             return strlen(e->cmd_defns[idx].cmd_desc);
117         return strlen(int_no_description);
118     case ENGINE_CTRL_GET_DESC_FROM_CMD:
119         if (e->cmd_defns[idx].cmd_desc)
120             return BIO_snprintf(s,
121                                 strlen(e->cmd_defns[idx].cmd_desc) + 1,
122                                 "%s", e->cmd_defns[idx].cmd_desc);
123         return BIO_snprintf(s, strlen(int_no_description) + 1, "%s",
124                             int_no_description);
125     case ENGINE_CTRL_GET_CMD_FLAGS:
126         return e->cmd_defns[idx].cmd_flags;
127     }
128     /* Shouldn't really be here ... */
129     ENGINEerr(ENGINE_F_INT_CTRL_HELPER, ENGINE_R_INTERNAL_LIST_ERROR);
130     return -1;
131 }
132
133 int ENGINE_ctrl(ENGINE *e, int cmd, long i, void *p, void (*f) (void))
134 {
135     int ctrl_exists, ref_exists;
136     if (e == NULL) {
137         ENGINEerr(ENGINE_F_ENGINE_CTRL, ERR_R_PASSED_NULL_PARAMETER);
138         return 0;
139     }
140     CRYPTO_THREAD_write_lock(global_engine_lock);
141     ref_exists = ((e->struct_ref > 0) ? 1 : 0);
142     CRYPTO_THREAD_unlock(global_engine_lock);
143     ctrl_exists = ((e->ctrl == NULL) ? 0 : 1);
144     if (!ref_exists) {
145         ENGINEerr(ENGINE_F_ENGINE_CTRL, ENGINE_R_NO_REFERENCE);
146         return 0;
147     }
148     /*
149      * Intercept any "root-level" commands before trying to hand them on to
150      * ctrl() handlers.
151      */
152     switch (cmd) {
153     case ENGINE_CTRL_HAS_CTRL_FUNCTION:
154         return ctrl_exists;
155     case ENGINE_CTRL_GET_FIRST_CMD_TYPE:
156     case ENGINE_CTRL_GET_NEXT_CMD_TYPE:
157     case ENGINE_CTRL_GET_CMD_FROM_NAME:
158     case ENGINE_CTRL_GET_NAME_LEN_FROM_CMD:
159     case ENGINE_CTRL_GET_NAME_FROM_CMD:
160     case ENGINE_CTRL_GET_DESC_LEN_FROM_CMD:
161     case ENGINE_CTRL_GET_DESC_FROM_CMD:
162     case ENGINE_CTRL_GET_CMD_FLAGS:
163         if (ctrl_exists && !(e->flags & ENGINE_FLAGS_MANUAL_CMD_CTRL))
164             return int_ctrl_helper(e, cmd, i, p, f);
165         if (!ctrl_exists) {
166             ENGINEerr(ENGINE_F_ENGINE_CTRL, ENGINE_R_NO_CONTROL_FUNCTION);
167             /*
168              * For these cmd-related functions, failure is indicated by a -1
169              * return value (because 0 is used as a valid return in some
170              * places).
171              */
172             return -1;
173         }
174     default:
175         break;
176     }
177     /* Anything else requires a ctrl() handler to exist. */
178     if (!ctrl_exists) {
179         ENGINEerr(ENGINE_F_ENGINE_CTRL, ENGINE_R_NO_CONTROL_FUNCTION);
180         return 0;
181     }
182     return e->ctrl(e, cmd, i, p, f);
183 }
184
185 int ENGINE_cmd_is_executable(ENGINE *e, int cmd)
186 {
187     int flags;
188     if ((flags =
189          ENGINE_ctrl(e, ENGINE_CTRL_GET_CMD_FLAGS, cmd, NULL, NULL)) < 0) {
190         ENGINEerr(ENGINE_F_ENGINE_CMD_IS_EXECUTABLE,
191                   ENGINE_R_INVALID_CMD_NUMBER);
192         return 0;
193     }
194     if (!(flags & ENGINE_CMD_FLAG_NO_INPUT) &&
195         !(flags & ENGINE_CMD_FLAG_NUMERIC) &&
196         !(flags & ENGINE_CMD_FLAG_STRING))
197         return 0;
198     return 1;
199 }
200
201 int ENGINE_ctrl_cmd(ENGINE *e, const char *cmd_name,
202                     long i, void *p, void (*f) (void), int cmd_optional)
203 {
204     int num;
205
206     if (e == NULL || cmd_name == NULL) {
207         ENGINEerr(ENGINE_F_ENGINE_CTRL_CMD, ERR_R_PASSED_NULL_PARAMETER);
208         return 0;
209     }
210     if (e->ctrl == NULL
211         || (num = ENGINE_ctrl(e, ENGINE_CTRL_GET_CMD_FROM_NAME,
212                               0, (void *)cmd_name, NULL)) <= 0) {
213         /*
214          * If the command didn't *have* to be supported, we fake success.
215          * This allows certain settings to be specified for multiple ENGINEs
216          * and only require a change of ENGINE id (without having to
217          * selectively apply settings). Eg. changing from a hardware device
218          * back to the regular software ENGINE without editing the config
219          * file, etc.
220          */
221         if (cmd_optional) {
222             ERR_clear_error();
223             return 1;
224         }
225         ENGINEerr(ENGINE_F_ENGINE_CTRL_CMD, ENGINE_R_INVALID_CMD_NAME);
226         return 0;
227     }
228     /*
229      * Force the result of the control command to 0 or 1, for the reasons
230      * mentioned before.
231      */
232     if (ENGINE_ctrl(e, num, i, p, f) > 0)
233         return 1;
234     return 0;
235 }
236
237 int ENGINE_ctrl_cmd_string(ENGINE *e, const char *cmd_name, const char *arg,
238                            int cmd_optional)
239 {
240     int num, flags;
241     long l;
242     char *ptr;
243
244     if (e == NULL || cmd_name == NULL) {
245         ENGINEerr(ENGINE_F_ENGINE_CTRL_CMD_STRING, ERR_R_PASSED_NULL_PARAMETER);
246         return 0;
247     }
248     if (e->ctrl == NULL
249         || (num = ENGINE_ctrl(e, ENGINE_CTRL_GET_CMD_FROM_NAME,
250                               0, (void *)cmd_name, NULL)) <= 0) {
251         /*
252          * If the command didn't *have* to be supported, we fake success.
253          * This allows certain settings to be specified for multiple ENGINEs
254          * and only require a change of ENGINE id (without having to
255          * selectively apply settings). Eg. changing from a hardware device
256          * back to the regular software ENGINE without editing the config
257          * file, etc.
258          */
259         if (cmd_optional) {
260             ERR_clear_error();
261             return 1;
262         }
263         ENGINEerr(ENGINE_F_ENGINE_CTRL_CMD_STRING, ENGINE_R_INVALID_CMD_NAME);
264         return 0;
265     }
266     if (!ENGINE_cmd_is_executable(e, num)) {
267         ENGINEerr(ENGINE_F_ENGINE_CTRL_CMD_STRING,
268                   ENGINE_R_CMD_NOT_EXECUTABLE);
269         return 0;
270     }
271
272     flags = ENGINE_ctrl(e, ENGINE_CTRL_GET_CMD_FLAGS, num, NULL, NULL);
273     if (flags < 0) {
274         /*
275          * Shouldn't happen, given that ENGINE_cmd_is_executable() returned
276          * success.
277          */
278         ENGINEerr(ENGINE_F_ENGINE_CTRL_CMD_STRING,
279                   ENGINE_R_INTERNAL_LIST_ERROR);
280         return 0;
281     }
282     /*
283      * If the command takes no input, there must be no input. And vice versa.
284      */
285     if (flags & ENGINE_CMD_FLAG_NO_INPUT) {
286         if (arg != NULL) {
287             ENGINEerr(ENGINE_F_ENGINE_CTRL_CMD_STRING,
288                       ENGINE_R_COMMAND_TAKES_NO_INPUT);
289             return 0;
290         }
291         /*
292          * We deliberately force the result of ENGINE_ctrl() to 0 or 1 rather
293          * than returning it as "return data". This is to ensure usage of
294          * these commands is consistent across applications and that certain
295          * applications don't understand it one way, and others another.
296          */
297         if (ENGINE_ctrl(e, num, 0, (void *)arg, NULL) > 0)
298             return 1;
299         return 0;
300     }
301     /* So, we require input */
302     if (arg == NULL) {
303         ENGINEerr(ENGINE_F_ENGINE_CTRL_CMD_STRING,
304                   ENGINE_R_COMMAND_TAKES_INPUT);
305         return 0;
306     }
307     /* If it takes string input, that's easy */
308     if (flags & ENGINE_CMD_FLAG_STRING) {
309         /* Same explanation as above */
310         if (ENGINE_ctrl(e, num, 0, (void *)arg, NULL) > 0)
311             return 1;
312         return 0;
313     }
314     /*
315      * If it doesn't take numeric either, then it is unsupported for use in a
316      * config-setting situation, which is what this function is for. This
317      * should never happen though, because ENGINE_cmd_is_executable() was
318      * used.
319      */
320     if (!(flags & ENGINE_CMD_FLAG_NUMERIC)) {
321         ENGINEerr(ENGINE_F_ENGINE_CTRL_CMD_STRING,
322                   ENGINE_R_INTERNAL_LIST_ERROR);
323         return 0;
324     }
325     l = strtol(arg, &ptr, 10);
326     if ((arg == ptr) || (*ptr != '\0')) {
327         ENGINEerr(ENGINE_F_ENGINE_CTRL_CMD_STRING,
328                   ENGINE_R_ARGUMENT_IS_NOT_A_NUMBER);
329         return 0;
330     }
331     /*
332      * Force the result of the control command to 0 or 1, for the reasons
333      * mentioned before.
334      */
335     if (ENGINE_ctrl(e, num, l, NULL, NULL) > 0)
336         return 1;
337     return 0;
338 }