1 /*
2  * Copyright 2020-2022 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 <openssl/core_object.h>
12 #include <openssl/provider.h>
13 #include <openssl/evp.h>
14 #include <openssl/ui.h>
15 #include <openssl/decoder.h>
16 #include <openssl/safestack.h>
17 #include <openssl/trace.h>
18 #include "crypto/evp.h"
19 #include "crypto/decoder.h"
20 #include "encoder_local.h"
21 
OSSL_DECODER_CTX_set_passphrase(OSSL_DECODER_CTX * ctx,const unsigned char * kstr,size_t klen)22 int OSSL_DECODER_CTX_set_passphrase(OSSL_DECODER_CTX *ctx,
23                                     const unsigned char *kstr,
24                                     size_t klen)
25 {
26     return ossl_pw_set_passphrase(&ctx->pwdata, kstr, klen);
27 }
28 
OSSL_DECODER_CTX_set_passphrase_ui(OSSL_DECODER_CTX * ctx,const UI_METHOD * ui_method,void * ui_data)29 int OSSL_DECODER_CTX_set_passphrase_ui(OSSL_DECODER_CTX *ctx,
30                                        const UI_METHOD *ui_method,
31                                        void *ui_data)
32 {
33     return ossl_pw_set_ui_method(&ctx->pwdata, ui_method, ui_data);
34 }
35 
OSSL_DECODER_CTX_set_pem_password_cb(OSSL_DECODER_CTX * ctx,pem_password_cb * cb,void * cbarg)36 int OSSL_DECODER_CTX_set_pem_password_cb(OSSL_DECODER_CTX *ctx,
37                                          pem_password_cb *cb, void *cbarg)
38 {
39     return ossl_pw_set_pem_password_cb(&ctx->pwdata, cb, cbarg);
40 }
41 
OSSL_DECODER_CTX_set_passphrase_cb(OSSL_DECODER_CTX * ctx,OSSL_PASSPHRASE_CALLBACK * cb,void * cbarg)42 int OSSL_DECODER_CTX_set_passphrase_cb(OSSL_DECODER_CTX *ctx,
43                                        OSSL_PASSPHRASE_CALLBACK *cb,
44                                        void *cbarg)
45 {
46     return ossl_pw_set_ossl_passphrase_cb(&ctx->pwdata, cb, cbarg);
47 }
48 
49 /*
50  * Support for OSSL_DECODER_CTX_new_for_pkey:
51  * The construct data, and collecting keymgmt information for it
52  */
53 
54 DEFINE_STACK_OF(EVP_KEYMGMT)
55 
56 struct decoder_pkey_data_st {
57     OSSL_LIB_CTX *libctx;
58     char *propq;
59     int selection;
60 
61     STACK_OF(EVP_KEYMGMT) *keymgmts;
62     char *object_type;           /* recorded object data type, may be NULL */
63     void **object;               /* Where the result should end up */
64 };
65 
decoder_construct_pkey(OSSL_DECODER_INSTANCE * decoder_inst,const OSSL_PARAM * params,void * construct_data)66 static int decoder_construct_pkey(OSSL_DECODER_INSTANCE *decoder_inst,
67                                   const OSSL_PARAM *params,
68                                   void *construct_data)
69 {
70     struct decoder_pkey_data_st *data = construct_data;
71     OSSL_DECODER *decoder = OSSL_DECODER_INSTANCE_get_decoder(decoder_inst);
72     void *decoderctx = OSSL_DECODER_INSTANCE_get_decoder_ctx(decoder_inst);
73     const OSSL_PROVIDER *decoder_prov = OSSL_DECODER_get0_provider(decoder);
74     EVP_KEYMGMT *keymgmt = NULL;
75     const OSSL_PROVIDER *keymgmt_prov = NULL;
76     int i, end;
77     /*
78      * |object_ref| points to a provider reference to an object, its exact
79      * contents entirely opaque to us, but may be passed to any provider
80      * function that expects this (such as OSSL_FUNC_keymgmt_load().
81      *
82      * This pointer is considered volatile, i.e. whatever it points at
83      * is assumed to be freed as soon as this function returns.
84      */
85     void *object_ref = NULL;
86     size_t object_ref_sz = 0;
87     const OSSL_PARAM *p;
88 
89     p = OSSL_PARAM_locate_const(params, OSSL_OBJECT_PARAM_DATA_TYPE);
90     if (p != NULL) {
91         char *object_type = NULL;
92 
93         if (!OSSL_PARAM_get_utf8_string(p, &object_type, 0))
94             return 0;
95         OPENSSL_free(data->object_type);
96         data->object_type = object_type;
97     }
98 
99     /*
100      * For stuff that should end up in an EVP_PKEY, we only accept an object
101      * reference for the moment.  This enforces that the key data itself
102      * remains with the provider.
103      */
104     p = OSSL_PARAM_locate_const(params, OSSL_OBJECT_PARAM_REFERENCE);
105     if (p == NULL || p->data_type != OSSL_PARAM_OCTET_STRING)
106         return 0;
107     object_ref = p->data;
108     object_ref_sz = p->data_size;
109 
110     /*
111      * First, we try to find a keymgmt that comes from the same provider as
112      * the decoder that passed the params.
113      */
114     end = sk_EVP_KEYMGMT_num(data->keymgmts);
115     for (i = 0; i < end; i++) {
116         keymgmt = sk_EVP_KEYMGMT_value(data->keymgmts, i);
117         keymgmt_prov = EVP_KEYMGMT_get0_provider(keymgmt);
118 
119         if (keymgmt_prov == decoder_prov
120             && evp_keymgmt_has_load(keymgmt)
121             && EVP_KEYMGMT_is_a(keymgmt, data->object_type))
122             break;
123     }
124     if (i < end) {
125         /* To allow it to be freed further down */
126         if (!EVP_KEYMGMT_up_ref(keymgmt))
127             return 0;
128     } else if ((keymgmt = EVP_KEYMGMT_fetch(data->libctx,
129                                             data->object_type,
130                                             data->propq)) != NULL) {
131         keymgmt_prov = EVP_KEYMGMT_get0_provider(keymgmt);
132     }
133 
134     if (keymgmt != NULL) {
135         EVP_PKEY *pkey = NULL;
136         void *keydata = NULL;
137 
138         /*
139          * If the EVP_KEYMGMT and the OSSL_DECODER are from the
140          * same provider, we assume that the KEYMGMT has a key loading
141          * function that can handle the provider reference we hold.
142          *
143          * Otherwise, we export from the decoder and import the
144          * result in the keymgmt.
145          */
146         if (keymgmt_prov == decoder_prov) {
147             keydata = evp_keymgmt_load(keymgmt, object_ref, object_ref_sz);
148         } else {
149             struct evp_keymgmt_util_try_import_data_st import_data;
150 
151             import_data.keymgmt = keymgmt;
152             import_data.keydata = NULL;
153             import_data.selection = data->selection;
154 
155             /*
156              * No need to check for errors here, the value of
157              * |import_data.keydata| is as much an indicator.
158              */
159             (void)decoder->export_object(decoderctx,
160                                          object_ref, object_ref_sz,
161                                          &evp_keymgmt_util_try_import,
162                                          &import_data);
163             keydata = import_data.keydata;
164             import_data.keydata = NULL;
165         }
166 
167         if (keydata != NULL
168             && (pkey = evp_keymgmt_util_make_pkey(keymgmt, keydata)) == NULL)
169             evp_keymgmt_freedata(keymgmt, keydata);
170 
171         *data->object = pkey;
172 
173         /*
174          * evp_keymgmt_util_make_pkey() increments the reference count when
175          * assigning the EVP_PKEY, so we can free the keymgmt here.
176          */
177         EVP_KEYMGMT_free(keymgmt);
178     }
179     /*
180      * We successfully looked through, |*ctx->object| determines if we
181      * actually found something.
182      */
183     return (*data->object != NULL);
184 }
185 
decoder_clean_pkey_construct_arg(void * construct_data)186 static void decoder_clean_pkey_construct_arg(void *construct_data)
187 {
188     struct decoder_pkey_data_st *data = construct_data;
189 
190     if (data != NULL) {
191         sk_EVP_KEYMGMT_pop_free(data->keymgmts, EVP_KEYMGMT_free);
192         OPENSSL_free(data->propq);
193         OPENSSL_free(data->object_type);
194         OPENSSL_free(data);
195     }
196 }
197 
collect_name(const char * name,void * arg)198 static void collect_name(const char *name, void *arg)
199 {
200     STACK_OF(OPENSSL_CSTRING) *names = arg;
201 
202     sk_OPENSSL_CSTRING_push(names, name);
203 }
204 
collect_keymgmt(EVP_KEYMGMT * keymgmt,void * arg)205 static void collect_keymgmt(EVP_KEYMGMT *keymgmt, void *arg)
206 {
207     STACK_OF(EVP_KEYMGMT) *keymgmts = arg;
208 
209     if (!EVP_KEYMGMT_up_ref(keymgmt) /* ref++ */)
210         return;
211     if (sk_EVP_KEYMGMT_push(keymgmts, keymgmt) <= 0) {
212         EVP_KEYMGMT_free(keymgmt);   /* ref-- */
213         return;
214     }
215 }
216 
217 struct collect_decoder_data_st {
218     STACK_OF(OPENSSL_CSTRING) *names;
219     OSSL_DECODER_CTX *ctx;
220 
221     int total;
222     unsigned int error_occurred:1;
223 };
224 
collect_decoder(OSSL_DECODER * decoder,void * arg)225 static void collect_decoder(OSSL_DECODER *decoder, void *arg)
226 {
227     struct collect_decoder_data_st *data = arg;
228     size_t i, end_i;
229     const OSSL_PROVIDER *prov = OSSL_DECODER_get0_provider(decoder);
230     void *provctx = OSSL_PROVIDER_get0_provider_ctx(prov);
231 
232     if (data->error_occurred)
233         return;
234 
235     if (data->names == NULL) {
236         data->error_occurred = 1;
237         return;
238     }
239 
240     /*
241      * Either the caller didn't give a selection, or if they did,
242      * the decoder must tell us if it supports that selection to
243      * be accepted.  If the decoder doesn't have |does_selection|,
244      * it's seen as taking anything.
245      */
246     if (decoder->does_selection != NULL
247             && !decoder->does_selection(provctx, data->ctx->selection))
248         return;
249 
250     OSSL_TRACE_BEGIN(DECODER) {
251         BIO_printf(trc_out,
252                    "(ctx %p) Checking out decoder %p:\n"
253                    "    %s with %s\n",
254                    (void *)data->ctx, (void *)decoder,
255                    OSSL_DECODER_get0_name(decoder),
256                    OSSL_DECODER_get0_properties(decoder));
257     } OSSL_TRACE_END(DECODER);
258 
259     end_i = sk_OPENSSL_CSTRING_num(data->names);
260     for (i = 0; i < end_i; i++) {
261         const char *name = sk_OPENSSL_CSTRING_value(data->names, i);
262 
263         if (OSSL_DECODER_is_a(decoder, name)) {
264             void *decoderctx = NULL;
265             OSSL_DECODER_INSTANCE *di = NULL;
266 
267             if ((decoderctx = decoder->newctx(provctx)) == NULL) {
268                 data->error_occurred = 1;
269                 return;
270             }
271             if ((di = ossl_decoder_instance_new(decoder, decoderctx)) == NULL) {
272                 decoder->freectx(decoderctx);
273                 data->error_occurred = 1;
274                 return;
275             }
276 
277             OSSL_TRACE_BEGIN(DECODER) {
278                 BIO_printf(trc_out,
279                            "(ctx %p) Checking out decoder %p:\n"
280                            "    %s with %s\n",
281                            (void *)data->ctx, (void *)decoder,
282                            OSSL_DECODER_get0_name(decoder),
283                            OSSL_DECODER_get0_properties(decoder));
284             } OSSL_TRACE_END(DECODER);
285 
286             if (!ossl_decoder_ctx_add_decoder_inst(data->ctx, di)) {
287                 ossl_decoder_instance_free(di);
288                 data->error_occurred = 1;
289                 return;
290             }
291             data->total++;
292 
293             /* Success */
294             return;
295         }
296     }
297 
298     /* Decoder not suitable - but not a fatal error */
299     data->error_occurred = 0;
300 }
301 
ossl_decoder_ctx_setup_for_pkey(OSSL_DECODER_CTX * ctx,EVP_PKEY ** pkey,const char * keytype,OSSL_LIB_CTX * libctx,const char * propquery)302 int ossl_decoder_ctx_setup_for_pkey(OSSL_DECODER_CTX *ctx,
303                                     EVP_PKEY **pkey, const char *keytype,
304                                     OSSL_LIB_CTX *libctx,
305                                     const char *propquery)
306 {
307     struct decoder_pkey_data_st *process_data = NULL;
308     STACK_OF(OPENSSL_CSTRING) *names = NULL;
309     const char *input_type = ctx->start_input_type;
310     const char *input_structure = ctx->input_structure;
311     int ok = 0;
312     int isecoid = 0;
313     int i, end;
314 
315     if (keytype != NULL
316             && (strcmp(keytype, "id-ecPublicKey") == 0
317                 || strcmp(keytype, "1.2.840.10045.2.1") == 0))
318         isecoid = 1;
319 
320     OSSL_TRACE_BEGIN(DECODER) {
321         BIO_printf(trc_out,
322                    "(ctx %p) Looking for decoders producing %s%s%s%s%s%s\n",
323                    (void *)ctx,
324                    keytype != NULL ? keytype : "",
325                    keytype != NULL ? " keys" : "keys of any type",
326                    input_type != NULL ? " from " : "",
327                    input_type != NULL ? input_type : "",
328                    input_structure != NULL ? " with " : "",
329                    input_structure != NULL ? input_structure : "");
330     } OSSL_TRACE_END(DECODER);
331 
332     if ((process_data = OPENSSL_zalloc(sizeof(*process_data))) == NULL
333         || (propquery != NULL
334             && (process_data->propq = OPENSSL_strdup(propquery)) == NULL)
335         || (process_data->keymgmts = sk_EVP_KEYMGMT_new_null()) == NULL
336         || (names = sk_OPENSSL_CSTRING_new_null()) == NULL) {
337         ERR_raise(ERR_LIB_OSSL_DECODER, ERR_R_MALLOC_FAILURE);
338         goto err;
339     }
340 
341     process_data->object = (void **)pkey;
342     process_data->libctx = libctx;
343     process_data->selection = ctx->selection;
344 
345     /* First, find all keymgmts to form goals */
346     EVP_KEYMGMT_do_all_provided(libctx, collect_keymgmt,
347                                 process_data->keymgmts);
348 
349     /* Then, we collect all the keymgmt names */
350     end = sk_EVP_KEYMGMT_num(process_data->keymgmts);
351     for (i = 0; i < end; i++) {
352         EVP_KEYMGMT *keymgmt = sk_EVP_KEYMGMT_value(process_data->keymgmts, i);
353 
354         /*
355          * If the key type is given by the caller, we only use the matching
356          * KEYMGMTs, otherwise we use them all.
357          * We have to special case SM2 here because of its abuse of the EC OID.
358          * The EC OID can be used to identify an EC key or an SM2 key - so if
359          * we have seen that OID we try both key types
360          */
361         if (keytype == NULL
362                 || EVP_KEYMGMT_is_a(keymgmt, keytype)
363                 || (isecoid && EVP_KEYMGMT_is_a(keymgmt, "SM2"))) {
364             if (!EVP_KEYMGMT_names_do_all(keymgmt, collect_name, names)) {
365                 ERR_raise(ERR_LIB_OSSL_DECODER, ERR_R_INTERNAL_ERROR);
366                 goto err;
367             }
368         }
369     }
370 
371     OSSL_TRACE_BEGIN(DECODER) {
372         end = sk_OPENSSL_CSTRING_num(names);
373         BIO_printf(trc_out,
374                    "    Found %d keytypes (possibly with duplicates)",
375                    end);
376         for (i = 0; i < end; i++)
377             BIO_printf(trc_out, "%s%s",
378                        i == 0 ? ": " : ", ",
379                        sk_OPENSSL_CSTRING_value(names, i));
380         BIO_printf(trc_out, "\n");
381     } OSSL_TRACE_END(DECODER);
382 
383     /*
384      * Finally, find all decoders that have any keymgmt of the collected
385      * keymgmt names
386      */
387     {
388         struct collect_decoder_data_st collect_decoder_data = { NULL, };
389 
390         collect_decoder_data.names = names;
391         collect_decoder_data.ctx = ctx;
392         OSSL_DECODER_do_all_provided(libctx,
393                                      collect_decoder, &collect_decoder_data);
394         sk_OPENSSL_CSTRING_free(names);
395         names = NULL;
396 
397         if (collect_decoder_data.error_occurred)
398             goto err;
399 
400         OSSL_TRACE_BEGIN(DECODER) {
401             BIO_printf(trc_out,
402                        "(ctx %p) Got %d decoders producing keys\n",
403                        (void *)ctx, collect_decoder_data.total);
404         } OSSL_TRACE_END(DECODER);
405     }
406 
407     if (OSSL_DECODER_CTX_get_num_decoders(ctx) != 0) {
408         if (!OSSL_DECODER_CTX_set_construct(ctx, decoder_construct_pkey)
409             || !OSSL_DECODER_CTX_set_construct_data(ctx, process_data)
410             || !OSSL_DECODER_CTX_set_cleanup(ctx,
411                                              decoder_clean_pkey_construct_arg))
412             goto err;
413 
414         process_data = NULL; /* Avoid it being freed */
415     }
416 
417     ok = 1;
418  err:
419     decoder_clean_pkey_construct_arg(process_data);
420     sk_OPENSSL_CSTRING_free(names);
421 
422     return ok;
423 }
424 
425 OSSL_DECODER_CTX *
OSSL_DECODER_CTX_new_for_pkey(EVP_PKEY ** pkey,const char * input_type,const char * input_structure,const char * keytype,int selection,OSSL_LIB_CTX * libctx,const char * propquery)426 OSSL_DECODER_CTX_new_for_pkey(EVP_PKEY **pkey,
427                               const char *input_type,
428                               const char *input_structure,
429                               const char *keytype, int selection,
430                               OSSL_LIB_CTX *libctx, const char *propquery)
431 {
432     OSSL_DECODER_CTX *ctx = NULL;
433 
434     if ((ctx = OSSL_DECODER_CTX_new()) == NULL) {
435         ERR_raise(ERR_LIB_OSSL_DECODER, ERR_R_MALLOC_FAILURE);
436         return NULL;
437     }
438 
439     OSSL_TRACE_BEGIN(DECODER) {
440         BIO_printf(trc_out,
441                    "(ctx %p) Looking for %s decoders with selection %d\n",
442                    (void *)ctx, keytype, selection);
443         BIO_printf(trc_out, "    input type: %s, input structure: %s\n",
444                    input_type, input_structure);
445     } OSSL_TRACE_END(DECODER);
446 
447     if (OSSL_DECODER_CTX_set_input_type(ctx, input_type)
448         && OSSL_DECODER_CTX_set_input_structure(ctx, input_structure)
449         && OSSL_DECODER_CTX_set_selection(ctx, selection)
450         && ossl_decoder_ctx_setup_for_pkey(ctx, pkey, keytype,
451                                            libctx, propquery)
452         && OSSL_DECODER_CTX_add_extra(ctx, libctx, propquery)) {
453         OSSL_TRACE_BEGIN(DECODER) {
454             BIO_printf(trc_out, "(ctx %p) Got %d decoders\n",
455                        (void *)ctx, OSSL_DECODER_CTX_get_num_decoders(ctx));
456         } OSSL_TRACE_END(DECODER);
457         return ctx;
458     }
459 
460     OSSL_DECODER_CTX_free(ctx);
461     return NULL;
462 }
463