xref: /freebsd/crypto/openssl/crypto/provider_conf.c (revision e0c4386e7e71d93b0edc0c8fa156263fc4a8b0b6)
1 /*
2  * Copyright 2019-2021 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 #include <string.h>
11 #include <openssl/trace.h>
12 #include <openssl/err.h>
13 #include <openssl/conf.h>
14 #include <openssl/safestack.h>
15 #include <openssl/provider.h>
16 #include "internal/provider.h"
17 #include "internal/cryptlib.h"
18 #include "provider_local.h"
19 
20 DEFINE_STACK_OF(OSSL_PROVIDER)
21 
22 /* PROVIDER config module */
23 
24 typedef struct {
25     CRYPTO_RWLOCK *lock;
26     STACK_OF(OSSL_PROVIDER) *activated_providers;
27 } PROVIDER_CONF_GLOBAL;
28 
prov_conf_ossl_ctx_new(OSSL_LIB_CTX * libctx)29 static void *prov_conf_ossl_ctx_new(OSSL_LIB_CTX *libctx)
30 {
31     PROVIDER_CONF_GLOBAL *pcgbl = OPENSSL_zalloc(sizeof(*pcgbl));
32 
33     if (pcgbl == NULL)
34         return NULL;
35 
36     pcgbl->lock = CRYPTO_THREAD_lock_new();
37     if (pcgbl->lock == NULL) {
38         OPENSSL_free(pcgbl);
39         return NULL;
40     }
41 
42     return pcgbl;
43 }
44 
prov_conf_ossl_ctx_free(void * vpcgbl)45 static void prov_conf_ossl_ctx_free(void *vpcgbl)
46 {
47     PROVIDER_CONF_GLOBAL *pcgbl = vpcgbl;
48 
49     sk_OSSL_PROVIDER_pop_free(pcgbl->activated_providers,
50                               ossl_provider_free);
51 
52     OSSL_TRACE(CONF, "Cleaned up providers\n");
53     CRYPTO_THREAD_lock_free(pcgbl->lock);
54     OPENSSL_free(pcgbl);
55 }
56 
57 static const OSSL_LIB_CTX_METHOD provider_conf_ossl_ctx_method = {
58     /* Must be freed before the provider store is freed */
59     OSSL_LIB_CTX_METHOD_PRIORITY_2,
60     prov_conf_ossl_ctx_new,
61     prov_conf_ossl_ctx_free,
62 };
63 
skip_dot(const char * name)64 static const char *skip_dot(const char *name)
65 {
66     const char *p = strchr(name, '.');
67 
68     if (p != NULL)
69         return p + 1;
70     return name;
71 }
72 
73 /*
74  * Parse the provider params section
75  * Returns:
76  * 1 for success
77  * 0 for non-fatal errors
78  * < 0 for fatal errors
79  */
provider_conf_params_internal(OSSL_PROVIDER * prov,OSSL_PROVIDER_INFO * provinfo,const char * name,const char * value,const CONF * cnf,STACK_OF (OPENSSL_CSTRING)* visited)80 static int provider_conf_params_internal(OSSL_PROVIDER *prov,
81                                          OSSL_PROVIDER_INFO *provinfo,
82                                          const char *name, const char *value,
83                                          const CONF *cnf,
84                                          STACK_OF(OPENSSL_CSTRING) *visited)
85 {
86     STACK_OF(CONF_VALUE) *sect;
87     int ok = 1;
88     int rc = 0;
89 
90     sect = NCONF_get_section(cnf, value);
91     if (sect != NULL) {
92         int i;
93         char buffer[512];
94         size_t buffer_len = 0;
95 
96         OSSL_TRACE1(CONF, "Provider params: start section %s\n", value);
97 
98         /*
99          * Check to see if the provided section value has already
100          * been visited.  If it has, then we have a recursive lookup
101          * in the configuration which isn't valid.  As such we should error
102          * out
103          */
104         for (i = 0; i < sk_OPENSSL_CSTRING_num(visited); i++) {
105             if (sk_OPENSSL_CSTRING_value(visited, i) == value) {
106                 ERR_raise(ERR_LIB_CONF, CONF_R_RECURSIVE_SECTION_REFERENCE);
107                 return -1;
108             }
109         }
110 
111         /*
112          * We've not visited this node yet, so record it on the stack
113          */
114         if (!sk_OPENSSL_CSTRING_push(visited, value))
115             return -1;
116 
117         if (name != NULL) {
118             OPENSSL_strlcpy(buffer, name, sizeof(buffer));
119             OPENSSL_strlcat(buffer, ".", sizeof(buffer));
120             buffer_len = strlen(buffer);
121         }
122 
123         for (i = 0; i < sk_CONF_VALUE_num(sect); i++) {
124             CONF_VALUE *sectconf = sk_CONF_VALUE_value(sect, i);
125 
126             if (buffer_len + strlen(sectconf->name) >= sizeof(buffer)) {
127                 sk_OPENSSL_CSTRING_pop(visited);
128                 return -1;
129             }
130             buffer[buffer_len] = '\0';
131             OPENSSL_strlcat(buffer, sectconf->name, sizeof(buffer));
132             rc = provider_conf_params_internal(prov, provinfo, buffer,
133                                                sectconf->value, cnf, visited);
134             if (rc < 0) {
135                 sk_OPENSSL_CSTRING_pop(visited);
136                 return rc;
137             }
138         }
139         sk_OPENSSL_CSTRING_pop(visited);
140 
141         OSSL_TRACE1(CONF, "Provider params: finish section %s\n", value);
142     } else {
143         OSSL_TRACE2(CONF, "Provider params: %s = %s\n", name, value);
144         if (prov != NULL)
145             ok = ossl_provider_add_parameter(prov, name, value);
146         else
147             ok = ossl_provider_info_add_parameter(provinfo, name, value);
148     }
149 
150     return ok;
151 }
152 
153 /*
154  * recursively parse the provider configuration section
155  * of the config file.
156  * Returns
157  * 1 on success
158  * 0 on non-fatal error
159  * < 0 on fatal errors
160  */
provider_conf_params(OSSL_PROVIDER * prov,OSSL_PROVIDER_INFO * provinfo,const char * name,const char * value,const CONF * cnf)161 static int provider_conf_params(OSSL_PROVIDER *prov,
162                                 OSSL_PROVIDER_INFO *provinfo,
163                                 const char *name, const char *value,
164                                 const CONF *cnf)
165 {
166     int rc;
167     STACK_OF(OPENSSL_CSTRING) *visited = sk_OPENSSL_CSTRING_new_null();
168 
169     if (visited == NULL)
170         return -1;
171 
172     rc = provider_conf_params_internal(prov, provinfo, name,
173                                        value, cnf, visited);
174 
175     sk_OPENSSL_CSTRING_free(visited);
176 
177     return rc;
178 }
179 
prov_already_activated(const char * name,STACK_OF (OSSL_PROVIDER)* activated)180 static int prov_already_activated(const char *name,
181                                   STACK_OF(OSSL_PROVIDER) *activated)
182 {
183     int i, max;
184 
185     if (activated == NULL)
186         return 0;
187 
188     max = sk_OSSL_PROVIDER_num(activated);
189     for (i = 0; i < max; i++) {
190         OSSL_PROVIDER *tstprov = sk_OSSL_PROVIDER_value(activated, i);
191 
192         if (strcmp(OSSL_PROVIDER_get0_name(tstprov), name) == 0) {
193             return 1;
194         }
195     }
196 
197     return 0;
198 }
199 
provider_conf_load(OSSL_LIB_CTX * libctx,const char * name,const char * value,const CONF * cnf)200 static int provider_conf_load(OSSL_LIB_CTX *libctx, const char *name,
201                               const char *value, const CONF *cnf)
202 {
203     int i;
204     STACK_OF(CONF_VALUE) *ecmds;
205     int soft = 0;
206     OSSL_PROVIDER *prov = NULL, *actual = NULL;
207     const char *path = NULL;
208     long activate = 0;
209     int ok = 0;
210     int added = 0;
211 
212     name = skip_dot(name);
213     OSSL_TRACE1(CONF, "Configuring provider %s\n", name);
214     /* Value is a section containing PROVIDER commands */
215     ecmds = NCONF_get_section(cnf, value);
216 
217     if (!ecmds) {
218         ERR_raise_data(ERR_LIB_CRYPTO, CRYPTO_R_PROVIDER_SECTION_ERROR,
219                        "section=%s not found", value);
220         return 0;
221     }
222 
223     /* Find the needed data first */
224     for (i = 0; i < sk_CONF_VALUE_num(ecmds); i++) {
225         CONF_VALUE *ecmd = sk_CONF_VALUE_value(ecmds, i);
226         const char *confname = skip_dot(ecmd->name);
227         const char *confvalue = ecmd->value;
228 
229         OSSL_TRACE2(CONF, "Provider command: %s = %s\n",
230                     confname, confvalue);
231 
232         /* First handle some special pseudo confs */
233 
234         /* Override provider name to use */
235         if (strcmp(confname, "identity") == 0)
236             name = confvalue;
237         else if (strcmp(confname, "soft_load") == 0)
238             soft = 1;
239         /* Load a dynamic PROVIDER */
240         else if (strcmp(confname, "module") == 0)
241             path = confvalue;
242         else if (strcmp(confname, "activate") == 0)
243             activate = 1;
244     }
245 
246     if (activate) {
247         PROVIDER_CONF_GLOBAL *pcgbl
248             = ossl_lib_ctx_get_data(libctx, OSSL_LIB_CTX_PROVIDER_CONF_INDEX,
249                                     &provider_conf_ossl_ctx_method);
250 
251         if (pcgbl == NULL || !CRYPTO_THREAD_write_lock(pcgbl->lock)) {
252             ERR_raise(ERR_LIB_CRYPTO, ERR_R_INTERNAL_ERROR);
253             return 0;
254         }
255         if (!prov_already_activated(name, pcgbl->activated_providers)) {
256             /*
257             * There is an attempt to activate a provider, so we should disable
258             * loading of fallbacks. Otherwise a misconfiguration could mean the
259             * intended provider does not get loaded. Subsequent fetches could
260             * then fallback to the default provider - which may be the wrong
261             * thing.
262             */
263             if (!ossl_provider_disable_fallback_loading(libctx)) {
264                 CRYPTO_THREAD_unlock(pcgbl->lock);
265                 ERR_raise(ERR_LIB_CRYPTO, ERR_R_INTERNAL_ERROR);
266                 return 0;
267             }
268             prov = ossl_provider_find(libctx, name, 1);
269             if (prov == NULL)
270                 prov = ossl_provider_new(libctx, name, NULL, 1);
271             if (prov == NULL) {
272                 CRYPTO_THREAD_unlock(pcgbl->lock);
273                 if (soft)
274                     ERR_clear_error();
275                 return 0;
276             }
277 
278             if (path != NULL)
279                 ossl_provider_set_module_path(prov, path);
280 
281             ok = provider_conf_params(prov, NULL, NULL, value, cnf);
282 
283             if (ok > 0) {
284                 if (!ossl_provider_activate(prov, 1, 0)) {
285                     ok = 0;
286                 } else if (!ossl_provider_add_to_store(prov, &actual, 0)) {
287                     ossl_provider_deactivate(prov, 1);
288                     ok = 0;
289                 } else if (actual != prov
290                            && !ossl_provider_activate(actual, 1, 0)) {
291                     ossl_provider_free(actual);
292                     ok = 0;
293                 } else {
294                     if (pcgbl->activated_providers == NULL)
295                         pcgbl->activated_providers = sk_OSSL_PROVIDER_new_null();
296                     if (pcgbl->activated_providers == NULL
297                         || !sk_OSSL_PROVIDER_push(pcgbl->activated_providers,
298                                                   actual)) {
299                         ossl_provider_deactivate(actual, 1);
300                         ossl_provider_free(actual);
301                         ok = 0;
302                     } else {
303                         ok = 1;
304                     }
305                 }
306             }
307             if (ok <= 0)
308                 ossl_provider_free(prov);
309         }
310         CRYPTO_THREAD_unlock(pcgbl->lock);
311     } else {
312         OSSL_PROVIDER_INFO entry;
313 
314         memset(&entry, 0, sizeof(entry));
315         ok = 1;
316         if (name != NULL) {
317             entry.name = OPENSSL_strdup(name);
318             if (entry.name == NULL) {
319                 ERR_raise(ERR_LIB_CRYPTO, ERR_R_MALLOC_FAILURE);
320                 ok = 0;
321             }
322         }
323         if (ok && path != NULL) {
324             entry.path = OPENSSL_strdup(path);
325             if (entry.path == NULL) {
326                 ERR_raise(ERR_LIB_CRYPTO, ERR_R_MALLOC_FAILURE);
327                 ok = 0;
328             }
329         }
330         if (ok)
331             ok = provider_conf_params(NULL, &entry, NULL, value, cnf);
332         if (ok >= 1 && (entry.path != NULL || entry.parameters != NULL)) {
333             ok = ossl_provider_info_add_to_store(libctx, &entry);
334             added = 1;
335         }
336         if (added == 0)
337             ossl_provider_info_clear(&entry);
338     }
339 
340     /*
341      * Provider activation returns a tristate:
342      * 1 for successful activation
343      * 0 for non-fatal activation failure
344      * < 0 for fatal activation failure
345      * We return success (1) for activation, (1) for non-fatal activation
346      * failure, and (0) for fatal activation failure
347      */
348     return ok >= 0;
349 }
350 
provider_conf_init(CONF_IMODULE * md,const CONF * cnf)351 static int provider_conf_init(CONF_IMODULE *md, const CONF *cnf)
352 {
353     STACK_OF(CONF_VALUE) *elist;
354     CONF_VALUE *cval;
355     int i;
356 
357     OSSL_TRACE1(CONF, "Loading providers module: section %s\n",
358                 CONF_imodule_get_value(md));
359 
360     /* Value is a section containing PROVIDERs to configure */
361     elist = NCONF_get_section(cnf, CONF_imodule_get_value(md));
362 
363     if (!elist) {
364         ERR_raise(ERR_LIB_CRYPTO, CRYPTO_R_PROVIDER_SECTION_ERROR);
365         return 0;
366     }
367 
368     for (i = 0; i < sk_CONF_VALUE_num(elist); i++) {
369         cval = sk_CONF_VALUE_value(elist, i);
370         if (!provider_conf_load(NCONF_get0_libctx((CONF *)cnf),
371                                 cval->name, cval->value, cnf))
372             return 0;
373     }
374 
375     return 1;
376 }
377 
ossl_provider_add_conf_module(void)378 void ossl_provider_add_conf_module(void)
379 {
380     OSSL_TRACE(CONF, "Adding config module 'providers'\n");
381     CONF_module_add("providers", provider_conf_init, NULL);
382 }
383