1/*
2 * Copyright 2019-2022 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 <openssl/core_names.h>
11#include "internal/cryptlib.h"
12#include "internal/nelem.h"
13#include "crypto/evp.h"
14#include "internal/core.h"
15#include "internal/provider.h"
16#include "evp_local.h"
17
18/*
19 * match_type() checks if two EVP_KEYMGMT are matching key types.  This
20 * function assumes that the caller has made all the necessary NULL checks.
21 */
22static int match_type(const EVP_KEYMGMT *keymgmt1, const EVP_KEYMGMT *keymgmt2)
23{
24    const char *name2 = EVP_KEYMGMT_get0_name(keymgmt2);
25
26    return EVP_KEYMGMT_is_a(keymgmt1, name2);
27}
28
29int evp_keymgmt_util_try_import(const OSSL_PARAM params[], void *arg)
30{
31    struct evp_keymgmt_util_try_import_data_st *data = arg;
32    int delete_on_error = 0;
33
34    /* Just in time creation of keydata */
35    if (data->keydata == NULL) {
36        if ((data->keydata = evp_keymgmt_newdata(data->keymgmt)) == NULL) {
37            ERR_raise(ERR_LIB_EVP, ERR_R_MALLOC_FAILURE);
38            return 0;
39        }
40        delete_on_error = 1;
41    }
42
43    /*
44     * It's fine if there was no data to transfer, we just end up with an
45     * empty destination key.
46     */
47    if (params[0].key == NULL)
48        return 1;
49
50    if (evp_keymgmt_import(data->keymgmt, data->keydata, data->selection,
51                           params))
52        return 1;
53    if (delete_on_error) {
54        evp_keymgmt_freedata(data->keymgmt, data->keydata);
55        data->keydata = NULL;
56    }
57    return 0;
58}
59
60int evp_keymgmt_util_assign_pkey(EVP_PKEY *pkey, EVP_KEYMGMT *keymgmt,
61                                 void *keydata)
62{
63    if (pkey == NULL || keymgmt == NULL || keydata == NULL
64        || !EVP_PKEY_set_type_by_keymgmt(pkey, keymgmt)) {
65        ERR_raise(ERR_LIB_EVP, ERR_R_INTERNAL_ERROR);
66        return 0;
67    }
68    pkey->keydata = keydata;
69    evp_keymgmt_util_cache_keyinfo(pkey);
70    return 1;
71}
72
73EVP_PKEY *evp_keymgmt_util_make_pkey(EVP_KEYMGMT *keymgmt, void *keydata)
74{
75    EVP_PKEY *pkey = NULL;
76
77    if (keymgmt == NULL
78        || keydata == NULL
79        || (pkey = EVP_PKEY_new()) == NULL
80        || !evp_keymgmt_util_assign_pkey(pkey, keymgmt, keydata)) {
81        EVP_PKEY_free(pkey);
82        return NULL;
83    }
84    return pkey;
85}
86
87int evp_keymgmt_util_export(const EVP_PKEY *pk, int selection,
88                            OSSL_CALLBACK *export_cb, void *export_cbarg)
89{
90    if (pk == NULL || export_cb == NULL)
91        return 0;
92    return evp_keymgmt_export(pk->keymgmt, pk->keydata, selection,
93                              export_cb, export_cbarg);
94}
95
96void *evp_keymgmt_util_export_to_provider(EVP_PKEY *pk, EVP_KEYMGMT *keymgmt,
97                                          int selection)
98{
99    struct evp_keymgmt_util_try_import_data_st import_data;
100    OP_CACHE_ELEM *op;
101
102    /* Export to where? */
103    if (keymgmt == NULL)
104        return NULL;
105
106    /* If we have an unassigned key, give up */
107    if (pk->keydata == NULL)
108        return NULL;
109
110    /*
111     * If |keymgmt| matches the "origin" |keymgmt|, there is no more to do.
112     * The "origin" is determined by the |keymgmt| pointers being identical
113     * or when the provider and the name ID match.  The latter case handles the
114     * situation where the fetch cache is flushed and a "new" key manager is
115     * created.
116     */
117    if (pk->keymgmt == keymgmt
118        || (pk->keymgmt->name_id == keymgmt->name_id
119            && pk->keymgmt->prov == keymgmt->prov))
120        return pk->keydata;
121
122    if (!CRYPTO_THREAD_read_lock(pk->lock))
123        return NULL;
124    /*
125     * If the provider native "origin" hasn't changed since last time, we
126     * try to find our keymgmt in the operation cache.  If it has changed
127     * and our keymgmt isn't found, we will clear the cache further down.
128     */
129    if (pk->dirty_cnt == pk->dirty_cnt_copy) {
130        /* If this key is already exported to |keymgmt|, no more to do */
131        op = evp_keymgmt_util_find_operation_cache(pk, keymgmt, selection);
132        if (op != NULL && op->keymgmt != NULL) {
133            void *ret = op->keydata;
134
135            CRYPTO_THREAD_unlock(pk->lock);
136            return ret;
137        }
138    }
139    CRYPTO_THREAD_unlock(pk->lock);
140
141    /* If the "origin" |keymgmt| doesn't support exporting, give up */
142    if (pk->keymgmt->export == NULL)
143        return NULL;
144
145    /*
146     * Make sure that the type of the keymgmt to export to matches the type
147     * of the "origin"
148     */
149    if (!ossl_assert(match_type(pk->keymgmt, keymgmt)))
150        return NULL;
151
152    /*
153     * We look at the already cached provider keys, and import from the
154     * first that supports it (i.e. use its export function), and export
155     * the imported data to the new provider.
156     */
157
158    /* Setup for the export callback */
159    import_data.keydata = NULL;  /* evp_keymgmt_util_try_import will create it */
160    import_data.keymgmt = keymgmt;
161    import_data.selection = selection;
162
163    /*
164     * The export function calls the callback (evp_keymgmt_util_try_import),
165     * which does the import for us.  If successful, we're done.
166     */
167    if (!evp_keymgmt_util_export(pk, selection,
168                                 &evp_keymgmt_util_try_import, &import_data))
169        /* If there was an error, bail out */
170        return NULL;
171
172    if (!CRYPTO_THREAD_write_lock(pk->lock)) {
173        evp_keymgmt_freedata(keymgmt, import_data.keydata);
174        return NULL;
175    }
176    /* Check to make sure some other thread didn't get there first */
177    op = evp_keymgmt_util_find_operation_cache(pk, keymgmt, selection);
178    if (op != NULL && op->keydata != NULL) {
179        void *ret = op->keydata;
180
181        CRYPTO_THREAD_unlock(pk->lock);
182
183        /*
184         * Another thread seemms to have already exported this so we abandon
185         * all the work we just did.
186         */
187        evp_keymgmt_freedata(keymgmt, import_data.keydata);
188
189        return ret;
190    }
191
192    /*
193     * If the dirty counter changed since last time, then clear the
194     * operation cache.  In that case, we know that |i| is zero.
195     */
196    if (pk->dirty_cnt != pk->dirty_cnt_copy)
197        evp_keymgmt_util_clear_operation_cache(pk, 0);
198
199    /* Add the new export to the operation cache */
200    if (!evp_keymgmt_util_cache_keydata(pk, keymgmt, import_data.keydata,
201                                        selection)) {
202        CRYPTO_THREAD_unlock(pk->lock);
203        evp_keymgmt_freedata(keymgmt, import_data.keydata);
204        return NULL;
205    }
206
207    /* Synchronize the dirty count */
208    pk->dirty_cnt_copy = pk->dirty_cnt;
209
210    CRYPTO_THREAD_unlock(pk->lock);
211
212    return import_data.keydata;
213}
214
215static void op_cache_free(OP_CACHE_ELEM *e)
216{
217    evp_keymgmt_freedata(e->keymgmt, e->keydata);
218    EVP_KEYMGMT_free(e->keymgmt);
219    OPENSSL_free(e);
220}
221
222int evp_keymgmt_util_clear_operation_cache(EVP_PKEY *pk, int locking)
223{
224    if (pk != NULL) {
225        if (locking && pk->lock != NULL && !CRYPTO_THREAD_write_lock(pk->lock))
226            return 0;
227        sk_OP_CACHE_ELEM_pop_free(pk->operation_cache, op_cache_free);
228        pk->operation_cache = NULL;
229        if (locking && pk->lock != NULL)
230            CRYPTO_THREAD_unlock(pk->lock);
231    }
232
233    return 1;
234}
235
236OP_CACHE_ELEM *evp_keymgmt_util_find_operation_cache(EVP_PKEY *pk,
237                                                     EVP_KEYMGMT *keymgmt,
238                                                     int selection)
239{
240    int i, end = sk_OP_CACHE_ELEM_num(pk->operation_cache);
241    OP_CACHE_ELEM *p;
242
243    /*
244     * A comparison and sk_P_CACHE_ELEM_find() are avoided to not cause
245     * problems when we've only a read lock.
246     */
247    for (i = 0; i < end; i++) {
248        p = sk_OP_CACHE_ELEM_value(pk->operation_cache, i);
249        if (keymgmt == p->keymgmt && (p->selection & selection) == selection)
250            return p;
251    }
252    return NULL;
253}
254
255int evp_keymgmt_util_cache_keydata(EVP_PKEY *pk, EVP_KEYMGMT *keymgmt,
256                                   void *keydata, int selection)
257{
258    OP_CACHE_ELEM *p = NULL;
259
260    if (keydata != NULL) {
261        if (pk->operation_cache == NULL) {
262            pk->operation_cache = sk_OP_CACHE_ELEM_new_null();
263            if (pk->operation_cache == NULL)
264                return 0;
265        }
266
267        p = OPENSSL_malloc(sizeof(*p));
268        if (p == NULL)
269            return 0;
270        p->keydata = keydata;
271        p->keymgmt = keymgmt;
272        p->selection = selection;
273
274        if (!EVP_KEYMGMT_up_ref(keymgmt)) {
275            OPENSSL_free(p);
276            return 0;
277        }
278
279        if (!sk_OP_CACHE_ELEM_push(pk->operation_cache, p)) {
280            EVP_KEYMGMT_free(keymgmt);
281            OPENSSL_free(p);
282            return 0;
283        }
284    }
285    return 1;
286}
287
288void evp_keymgmt_util_cache_keyinfo(EVP_PKEY *pk)
289{
290    /*
291     * Cache information about the provider "origin" key.
292     *
293     * This services functions like EVP_PKEY_get_size, EVP_PKEY_get_bits, etc
294     */
295    if (pk->keydata != NULL) {
296        int bits = 0;
297        int security_bits = 0;
298        int size = 0;
299        OSSL_PARAM params[4];
300
301        params[0] = OSSL_PARAM_construct_int(OSSL_PKEY_PARAM_BITS, &bits);
302        params[1] = OSSL_PARAM_construct_int(OSSL_PKEY_PARAM_SECURITY_BITS,
303                                             &security_bits);
304        params[2] = OSSL_PARAM_construct_int(OSSL_PKEY_PARAM_MAX_SIZE, &size);
305        params[3] = OSSL_PARAM_construct_end();
306        if (evp_keymgmt_get_params(pk->keymgmt, pk->keydata, params)) {
307            pk->cache.size = size;
308            pk->cache.bits = bits;
309            pk->cache.security_bits = security_bits;
310        }
311    }
312}
313
314void *evp_keymgmt_util_fromdata(EVP_PKEY *target, EVP_KEYMGMT *keymgmt,
315                                int selection, const OSSL_PARAM params[])
316{
317    void *keydata = NULL;
318
319    if ((keydata = evp_keymgmt_newdata(keymgmt)) == NULL
320        || !evp_keymgmt_import(keymgmt, keydata, selection, params)
321        || !evp_keymgmt_util_assign_pkey(target, keymgmt, keydata)) {
322        evp_keymgmt_freedata(keymgmt, keydata);
323        keydata = NULL;
324    }
325    return keydata;
326}
327
328int evp_keymgmt_util_has(EVP_PKEY *pk, int selection)
329{
330    /* Check if key is even assigned */
331    if (pk->keymgmt == NULL)
332        return 0;
333
334    return evp_keymgmt_has(pk->keymgmt, pk->keydata, selection);
335}
336
337/*
338 * evp_keymgmt_util_match() doesn't just look at the provider side "origin",
339 * but also in the operation cache to see if there's any common keymgmt that
340 * supplies OP_keymgmt_match.
341 *
342 * evp_keymgmt_util_match() adheres to the return values that EVP_PKEY_eq()
343 * and EVP_PKEY_parameters_eq() return, i.e.:
344 *
345 *  1   same key
346 *  0   not same key
347 * -1   not same key type
348 * -2   unsupported operation
349 */
350int evp_keymgmt_util_match(EVP_PKEY *pk1, EVP_PKEY *pk2, int selection)
351{
352    EVP_KEYMGMT *keymgmt1 = NULL, *keymgmt2 = NULL;
353    void *keydata1 = NULL, *keydata2 = NULL;
354
355    if (pk1 == NULL || pk2 == NULL) {
356        if (pk1 == NULL && pk2 == NULL)
357            return 1;
358        return 0;
359    }
360
361    keymgmt1 = pk1->keymgmt;
362    keydata1 = pk1->keydata;
363    keymgmt2 = pk2->keymgmt;
364    keydata2 = pk2->keydata;
365
366    if (keymgmt1 != keymgmt2) {
367        /*
368         * The condition for a successful cross export is that the
369         * keydata to be exported is NULL (typed, but otherwise empty
370         * EVP_PKEY), or that it was possible to export it with
371         * evp_keymgmt_util_export_to_provider().
372         *
373         * We use |ok| to determine if it's ok to cross export one way,
374         * but also to determine if we should attempt a cross export
375         * the other way.  There's no point doing it both ways.
376         */
377        int ok = 0;
378
379        /* Complex case, where the keymgmt differ */
380        if (keymgmt1 != NULL
381            && keymgmt2 != NULL
382            && !match_type(keymgmt1, keymgmt2)) {
383            ERR_raise(ERR_LIB_EVP, EVP_R_DIFFERENT_KEY_TYPES);
384            return -1;           /* Not the same type */
385        }
386
387        /*
388         * The key types are determined to match, so we try cross export,
389         * but only to keymgmt's that supply a matching function.
390         */
391        if (keymgmt2 != NULL
392            && keymgmt2->match != NULL) {
393            void *tmp_keydata = NULL;
394
395            ok = 1;
396            if (keydata1 != NULL) {
397                tmp_keydata =
398                    evp_keymgmt_util_export_to_provider(pk1, keymgmt2,
399                                                        selection);
400                ok = (tmp_keydata != NULL);
401            }
402            if (ok) {
403                keymgmt1 = keymgmt2;
404                keydata1 = tmp_keydata;
405            }
406        }
407        /*
408         * If we've successfully cross exported one way, there's no point
409         * doing it the other way, hence the |!ok| check.
410         */
411        if (!ok
412            && keymgmt1 != NULL
413            && keymgmt1->match != NULL) {
414            void *tmp_keydata = NULL;
415
416            ok = 1;
417            if (keydata2 != NULL) {
418                tmp_keydata =
419                    evp_keymgmt_util_export_to_provider(pk2, keymgmt1,
420                                                        selection);
421                ok = (tmp_keydata != NULL);
422            }
423            if (ok) {
424                keymgmt2 = keymgmt1;
425                keydata2 = tmp_keydata;
426            }
427        }
428    }
429
430    /* If we still don't have matching keymgmt implementations, we give up */
431    if (keymgmt1 != keymgmt2)
432        return -2;
433
434    /* If both keydata are NULL, then they're the same key */
435    if (keydata1 == NULL && keydata2 == NULL)
436        return 1;
437    /* If only one of the keydata is NULL, then they're different keys */
438    if (keydata1 == NULL || keydata2 == NULL)
439        return 0;
440    /* If both keydata are non-NULL, we let the backend decide */
441    return evp_keymgmt_match(keymgmt1, keydata1, keydata2, selection);
442}
443
444int evp_keymgmt_util_copy(EVP_PKEY *to, EVP_PKEY *from, int selection)
445{
446    /* Save copies of pointers we want to play with without affecting |to| */
447    EVP_KEYMGMT *to_keymgmt = to->keymgmt;
448    void *to_keydata = to->keydata, *alloc_keydata = NULL;
449
450    /* An unassigned key can't be copied */
451    if (from == NULL || from->keydata == NULL)
452        return 0;
453
454    /*
455     * If |to| is unassigned, ensure it gets the same KEYMGMT as |from|,
456     * Note that the final setting of KEYMGMT is done further down, with
457     * EVP_PKEY_set_type_by_keymgmt(); we don't want to do that prematurely.
458     */
459    if (to_keymgmt == NULL)
460        to_keymgmt = from->keymgmt;
461
462    if (to_keymgmt == from->keymgmt && to_keymgmt->dup != NULL
463        && to_keydata == NULL) {
464        to_keydata = alloc_keydata = evp_keymgmt_dup(to_keymgmt,
465                                                     from->keydata,
466                                                     selection);
467        if (to_keydata == NULL)
468            return 0;
469    } else if (match_type(to_keymgmt, from->keymgmt)) {
470        struct evp_keymgmt_util_try_import_data_st import_data;
471
472        import_data.keymgmt = to_keymgmt;
473        import_data.keydata = to_keydata;
474        import_data.selection = selection;
475
476        if (!evp_keymgmt_util_export(from, selection,
477                                     &evp_keymgmt_util_try_import,
478                                     &import_data))
479            return 0;
480
481        /*
482         * In case to_keydata was previously unallocated,
483         * evp_keymgmt_util_try_import() may have created it for us.
484         */
485        if (to_keydata == NULL)
486            to_keydata = alloc_keydata = import_data.keydata;
487    } else {
488        ERR_raise(ERR_LIB_EVP, EVP_R_DIFFERENT_KEY_TYPES);
489        return 0;
490    }
491
492    /*
493     * We only need to set the |to| type when its |keymgmt| isn't set.
494     * We can then just set its |keydata| to what we have, which might
495     * be exactly what it had when entering this function.
496     * This is a bit different from using evp_keymgmt_util_assign_pkey(),
497     * which isn't as careful with |to|'s original |keymgmt|, since it's
498     * meant to forcibly reassign an EVP_PKEY no matter what, which is
499     * why we don't use that one here.
500     */
501    if (to->keymgmt == NULL
502        && !EVP_PKEY_set_type_by_keymgmt(to, to_keymgmt)) {
503        evp_keymgmt_freedata(to_keymgmt, alloc_keydata);
504        return 0;
505    }
506    to->keydata = to_keydata;
507    evp_keymgmt_util_cache_keyinfo(to);
508
509    return 1;
510}
511
512void *evp_keymgmt_util_gen(EVP_PKEY *target, EVP_KEYMGMT *keymgmt,
513                           void *genctx, OSSL_CALLBACK *cb, void *cbarg)
514{
515    void *keydata = NULL;
516
517    if ((keydata = evp_keymgmt_gen(keymgmt, genctx, cb, cbarg)) == NULL
518        || !evp_keymgmt_util_assign_pkey(target, keymgmt, keydata)) {
519        evp_keymgmt_freedata(keymgmt, keydata);
520        keydata = NULL;
521    }
522
523    return keydata;
524}
525
526/*
527 * Returns the same numbers as EVP_PKEY_get_default_digest_name()
528 * When the string from the EVP_KEYMGMT implementation is "", we use
529 * SN_undef, since that corresponds to what EVP_PKEY_get_default_nid()
530 * returns for no digest.
531 */
532int evp_keymgmt_util_get_deflt_digest_name(EVP_KEYMGMT *keymgmt,
533                                           void *keydata,
534                                           char *mdname, size_t mdname_sz)
535{
536    OSSL_PARAM params[3];
537    char mddefault[100] = "";
538    char mdmandatory[100] = "";
539    char *result = NULL;
540    int rv = -2;
541
542    params[0] =
543        OSSL_PARAM_construct_utf8_string(OSSL_PKEY_PARAM_DEFAULT_DIGEST,
544                                         mddefault, sizeof(mddefault));
545    params[1] =
546        OSSL_PARAM_construct_utf8_string(OSSL_PKEY_PARAM_MANDATORY_DIGEST,
547                                         mdmandatory,
548                                         sizeof(mdmandatory));
549    params[2] = OSSL_PARAM_construct_end();
550
551    if (!evp_keymgmt_get_params(keymgmt, keydata, params))
552        return 0;
553
554    if (OSSL_PARAM_modified(params + 1)) {
555        if (params[1].return_size <= 1) /* Only a NUL byte */
556            result = SN_undef;
557        else
558            result = mdmandatory;
559        rv = 2;
560    } else if (OSSL_PARAM_modified(params)) {
561        if (params[0].return_size <= 1) /* Only a NUL byte */
562            result = SN_undef;
563        else
564            result = mddefault;
565        rv = 1;
566    }
567    if (rv > 0)
568        OPENSSL_strlcpy(mdname, result, mdname_sz);
569    return rv;
570}
571
572/*
573 * If |keymgmt| has the method function |query_operation_name|, use it to get
574 * the name of a supported operation identity.  Otherwise, return the keytype,
575 * assuming that it works as a default operation name.
576 */
577const char *evp_keymgmt_util_query_operation_name(EVP_KEYMGMT *keymgmt,
578                                                  int op_id)
579{
580    const char *name = NULL;
581
582    if (keymgmt != NULL) {
583        if (keymgmt->query_operation_name != NULL)
584            name = keymgmt->query_operation_name(op_id);
585        if (name == NULL)
586            name = EVP_KEYMGMT_get0_name(keymgmt);
587    }
588    return name;
589}
590