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
20DEFINE_STACK_OF(OSSL_PROVIDER)
21
22/* PROVIDER config module */
23
24typedef struct {
25    CRYPTO_RWLOCK *lock;
26    STACK_OF(OSSL_PROVIDER) *activated_providers;
27} PROVIDER_CONF_GLOBAL;
28
29static 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
45static 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
57static 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
64static 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 */
80static 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 */
161static 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
180static 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
200static 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
351static 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
378void 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