1 /*
2  * Copyright 2019-2023 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 <assert.h>
11 #include <openssl/crypto.h>
12 #include <openssl/core_dispatch.h>
13 #include <openssl/core_names.h>
14 #include <openssl/provider.h>
15 #include <openssl/evp.h>
16 #include "internal/provider.h"
17 #include "internal/cryptlib.h"
18 #include "crypto/evp.h"
19 
20 DEFINE_STACK_OF(OSSL_PROVIDER)
21 
22 struct child_prov_globals {
23     const OSSL_CORE_HANDLE *handle;
24     const OSSL_CORE_HANDLE *curr_prov;
25     CRYPTO_RWLOCK *lock;
26     OSSL_FUNC_core_get_libctx_fn *c_get_libctx;
27     OSSL_FUNC_provider_register_child_cb_fn *c_provider_register_child_cb;
28     OSSL_FUNC_provider_deregister_child_cb_fn *c_provider_deregister_child_cb;
29     OSSL_FUNC_provider_name_fn *c_prov_name;
30     OSSL_FUNC_provider_get0_provider_ctx_fn *c_prov_get0_provider_ctx;
31     OSSL_FUNC_provider_get0_dispatch_fn *c_prov_get0_dispatch;
32     OSSL_FUNC_provider_up_ref_fn *c_prov_up_ref;
33     OSSL_FUNC_provider_free_fn *c_prov_free;
34 };
35 
child_prov_ossl_ctx_new(OSSL_LIB_CTX * libctx)36 static void *child_prov_ossl_ctx_new(OSSL_LIB_CTX *libctx)
37 {
38     return OPENSSL_zalloc(sizeof(struct child_prov_globals));
39 }
40 
child_prov_ossl_ctx_free(void * vgbl)41 static void child_prov_ossl_ctx_free(void *vgbl)
42 {
43     struct child_prov_globals *gbl = vgbl;
44 
45     CRYPTO_THREAD_lock_free(gbl->lock);
46     OPENSSL_free(gbl);
47 }
48 
49 static const OSSL_LIB_CTX_METHOD child_prov_ossl_ctx_method = {
50     OSSL_LIB_CTX_METHOD_LOW_PRIORITY,
51     child_prov_ossl_ctx_new,
52     child_prov_ossl_ctx_free,
53 };
54 
55 static OSSL_provider_init_fn ossl_child_provider_init;
56 
ossl_child_provider_init(const OSSL_CORE_HANDLE * handle,const OSSL_DISPATCH * in,const OSSL_DISPATCH ** out,void ** provctx)57 static int ossl_child_provider_init(const OSSL_CORE_HANDLE *handle,
58                                     const OSSL_DISPATCH *in,
59                                     const OSSL_DISPATCH **out,
60                                     void **provctx)
61 {
62     OSSL_FUNC_core_get_libctx_fn *c_get_libctx = NULL;
63     OSSL_LIB_CTX *ctx;
64     struct child_prov_globals *gbl;
65 
66     for (; in->function_id != 0; in++) {
67         switch (in->function_id) {
68         case OSSL_FUNC_CORE_GET_LIBCTX:
69             c_get_libctx = OSSL_FUNC_core_get_libctx(in);
70             break;
71         default:
72             /* Just ignore anything we don't understand */
73             break;
74         }
75     }
76 
77     if (c_get_libctx == NULL)
78         return 0;
79 
80     /*
81      * We need an OSSL_LIB_CTX but c_get_libctx returns OPENSSL_CORE_CTX. We are
82      * a built-in provider and so we can get away with this cast. Normal
83      * providers can't do this.
84      */
85     ctx = (OSSL_LIB_CTX *)c_get_libctx(handle);
86 
87     gbl = ossl_lib_ctx_get_data(ctx, OSSL_LIB_CTX_CHILD_PROVIDER_INDEX,
88                                 &child_prov_ossl_ctx_method);
89     if (gbl == NULL)
90         return 0;
91 
92     *provctx = gbl->c_prov_get0_provider_ctx(gbl->curr_prov);
93     *out = gbl->c_prov_get0_dispatch(gbl->curr_prov);
94 
95     return 1;
96 }
97 
provider_create_child_cb(const OSSL_CORE_HANDLE * prov,void * cbdata)98 static int provider_create_child_cb(const OSSL_CORE_HANDLE *prov, void *cbdata)
99 {
100     OSSL_LIB_CTX *ctx = cbdata;
101     struct child_prov_globals *gbl;
102     const char *provname;
103     OSSL_PROVIDER *cprov;
104     int ret = 0;
105 
106     gbl = ossl_lib_ctx_get_data(ctx, OSSL_LIB_CTX_CHILD_PROVIDER_INDEX,
107                                 &child_prov_ossl_ctx_method);
108     if (gbl == NULL)
109         return 0;
110 
111     if (!CRYPTO_THREAD_write_lock(gbl->lock))
112         return 0;
113 
114     provname = gbl->c_prov_name(prov);
115 
116     /*
117      * We're operating under a lock so we can store the "current" provider in
118      * the global data.
119      */
120     gbl->curr_prov = prov;
121 
122     if ((cprov = ossl_provider_find(ctx, provname, 1)) != NULL) {
123         /*
124          * We free the newly created ref. We rely on the provider sticking around
125          * in the provider store.
126          */
127         ossl_provider_free(cprov);
128 
129         /*
130          * The provider already exists. It could be a previously created child,
131          * or it could have been explicitly loaded. If explicitly loaded we
132          * ignore it - i.e. we don't start treating it like a child.
133          */
134         if (!ossl_provider_activate(cprov, 0, 1))
135             goto err;
136     } else {
137         /*
138          * Create it - passing 1 as final param so we don't try and recursively
139          * init children
140          */
141         if ((cprov = ossl_provider_new(ctx, provname, ossl_child_provider_init,
142                                        1)) == NULL)
143             goto err;
144 
145         if (!ossl_provider_activate(cprov, 0, 0)) {
146             ossl_provider_free(cprov);
147             goto err;
148         }
149 
150         if (!ossl_provider_set_child(cprov, prov)
151             || !ossl_provider_add_to_store(cprov, NULL, 0)) {
152             ossl_provider_deactivate(cprov, 0);
153             ossl_provider_free(cprov);
154             goto err;
155         }
156     }
157 
158     ret = 1;
159  err:
160     CRYPTO_THREAD_unlock(gbl->lock);
161     return ret;
162 }
163 
provider_remove_child_cb(const OSSL_CORE_HANDLE * prov,void * cbdata)164 static int provider_remove_child_cb(const OSSL_CORE_HANDLE *prov, void *cbdata)
165 {
166     OSSL_LIB_CTX *ctx = cbdata;
167     struct child_prov_globals *gbl;
168     const char *provname;
169     OSSL_PROVIDER *cprov;
170 
171     gbl = ossl_lib_ctx_get_data(ctx, OSSL_LIB_CTX_CHILD_PROVIDER_INDEX,
172                                 &child_prov_ossl_ctx_method);
173     if (gbl == NULL)
174         return 0;
175 
176     provname = gbl->c_prov_name(prov);
177     cprov = ossl_provider_find(ctx, provname, 1);
178     if (cprov == NULL)
179         return 0;
180     /*
181      * ossl_provider_find ups the ref count, so we free it again here. We can
182      * rely on the provider store reference count.
183      */
184     ossl_provider_free(cprov);
185     if (ossl_provider_is_child(cprov)
186             && !ossl_provider_deactivate(cprov, 1))
187         return 0;
188 
189     return 1;
190 }
191 
provider_global_props_cb(const char * props,void * cbdata)192 static int provider_global_props_cb(const char *props, void *cbdata)
193 {
194     OSSL_LIB_CTX *ctx = cbdata;
195 
196     return evp_set_default_properties_int(ctx, props, 0, 1);
197 }
198 
ossl_provider_init_as_child(OSSL_LIB_CTX * ctx,const OSSL_CORE_HANDLE * handle,const OSSL_DISPATCH * in)199 int ossl_provider_init_as_child(OSSL_LIB_CTX *ctx,
200                                 const OSSL_CORE_HANDLE *handle,
201                                 const OSSL_DISPATCH *in)
202 {
203     struct child_prov_globals *gbl;
204 
205     if (ctx == NULL)
206         return 0;
207 
208     gbl = ossl_lib_ctx_get_data(ctx, OSSL_LIB_CTX_CHILD_PROVIDER_INDEX,
209                                 &child_prov_ossl_ctx_method);
210     if (gbl == NULL)
211         return 0;
212 
213     gbl->handle = handle;
214     for (; in->function_id != 0; in++) {
215         switch (in->function_id) {
216         case OSSL_FUNC_CORE_GET_LIBCTX:
217             gbl->c_get_libctx = OSSL_FUNC_core_get_libctx(in);
218             break;
219         case OSSL_FUNC_PROVIDER_REGISTER_CHILD_CB:
220             gbl->c_provider_register_child_cb
221                 = OSSL_FUNC_provider_register_child_cb(in);
222             break;
223         case OSSL_FUNC_PROVIDER_DEREGISTER_CHILD_CB:
224             gbl->c_provider_deregister_child_cb
225                 = OSSL_FUNC_provider_deregister_child_cb(in);
226             break;
227         case OSSL_FUNC_PROVIDER_NAME:
228             gbl->c_prov_name = OSSL_FUNC_provider_name(in);
229             break;
230         case OSSL_FUNC_PROVIDER_GET0_PROVIDER_CTX:
231             gbl->c_prov_get0_provider_ctx
232                 = OSSL_FUNC_provider_get0_provider_ctx(in);
233             break;
234         case OSSL_FUNC_PROVIDER_GET0_DISPATCH:
235             gbl->c_prov_get0_dispatch = OSSL_FUNC_provider_get0_dispatch(in);
236             break;
237         case OSSL_FUNC_PROVIDER_UP_REF:
238             gbl->c_prov_up_ref
239                 = OSSL_FUNC_provider_up_ref(in);
240             break;
241         case OSSL_FUNC_PROVIDER_FREE:
242             gbl->c_prov_free = OSSL_FUNC_provider_free(in);
243             break;
244         default:
245             /* Just ignore anything we don't understand */
246             break;
247         }
248     }
249 
250     if (gbl->c_get_libctx == NULL
251             || gbl->c_provider_register_child_cb == NULL
252             || gbl->c_prov_name == NULL
253             || gbl->c_prov_get0_provider_ctx == NULL
254             || gbl->c_prov_get0_dispatch == NULL
255             || gbl->c_prov_up_ref == NULL
256             || gbl->c_prov_free == NULL)
257         return 0;
258 
259     gbl->lock = CRYPTO_THREAD_lock_new();
260     if (gbl->lock == NULL)
261         return 0;
262 
263     if (!gbl->c_provider_register_child_cb(gbl->handle,
264                                            provider_create_child_cb,
265                                            provider_remove_child_cb,
266                                            provider_global_props_cb,
267                                            ctx))
268         return 0;
269 
270     return 1;
271 }
272 
ossl_provider_deinit_child(OSSL_LIB_CTX * ctx)273 void ossl_provider_deinit_child(OSSL_LIB_CTX *ctx)
274 {
275     struct child_prov_globals *gbl
276         = ossl_lib_ctx_get_data(ctx, OSSL_LIB_CTX_CHILD_PROVIDER_INDEX,
277                                 &child_prov_ossl_ctx_method);
278     if (gbl == NULL)
279         return;
280 
281     gbl->c_provider_deregister_child_cb(gbl->handle);
282 }
283 
284 /*
285  * ossl_provider_up_ref_parent() and ossl_provider_free_parent() do
286  * nothing in "self-referencing" child providers, i.e. when the parent
287  * of the child provider is the same as the provider where this child
288  * provider was created.
289  * This allows the teardown function in the parent provider to be called
290  * at the correct moment.
291  * For child providers in other providers, the reference count is done to
292  * ensure that cross referencing is recorded.  These should be cleared up
293  * through that providers teardown, as part of freeing its child libctx.
294  */
295 
ossl_provider_up_ref_parent(OSSL_PROVIDER * prov,int activate)296 int ossl_provider_up_ref_parent(OSSL_PROVIDER *prov, int activate)
297 {
298     struct child_prov_globals *gbl;
299     const OSSL_CORE_HANDLE *parent_handle;
300 
301     gbl = ossl_lib_ctx_get_data(ossl_provider_libctx(prov),
302                                 OSSL_LIB_CTX_CHILD_PROVIDER_INDEX,
303                                 &child_prov_ossl_ctx_method);
304     if (gbl == NULL)
305         return 0;
306 
307     parent_handle = ossl_provider_get_parent(prov);
308     if (parent_handle == gbl->handle)
309         return 1;
310     return gbl->c_prov_up_ref(parent_handle, activate);
311 }
312 
ossl_provider_free_parent(OSSL_PROVIDER * prov,int deactivate)313 int ossl_provider_free_parent(OSSL_PROVIDER *prov, int deactivate)
314 {
315     struct child_prov_globals *gbl;
316     const OSSL_CORE_HANDLE *parent_handle;
317 
318     gbl = ossl_lib_ctx_get_data(ossl_provider_libctx(prov),
319                                 OSSL_LIB_CTX_CHILD_PROVIDER_INDEX,
320                                 &child_prov_ossl_ctx_method);
321     if (gbl == NULL)
322         return 0;
323 
324     parent_handle = ossl_provider_get_parent(prov);
325     if (parent_handle == gbl->handle)
326         return 1;
327     return gbl->c_prov_free(ossl_provider_get_parent(prov), deactivate);
328 }
329