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 "e_os.h"                /* strcasecmp on Windows */
11 #include <openssl/err.h>
12 #include <openssl/ui.h>
13 #include <openssl/params.h>
14 #include <openssl/encoder.h>
15 #include <openssl/core_names.h>
16 #include <openssl/provider.h>
17 #include <openssl/safestack.h>
18 #include <openssl/trace.h>
19 #include "internal/provider.h"
20 #include "internal/property.h"
21 #include "crypto/evp.h"
22 #include "encoder_local.h"
23 
DEFINE_STACK_OF(OSSL_ENCODER)24 DEFINE_STACK_OF(OSSL_ENCODER)
25 
26 int OSSL_ENCODER_CTX_set_cipher(OSSL_ENCODER_CTX *ctx,
27                                 const char *cipher_name,
28                                 const char *propquery)
29 {
30     OSSL_PARAM params[] = { OSSL_PARAM_END, OSSL_PARAM_END, OSSL_PARAM_END };
31 
32     params[0] =
33         OSSL_PARAM_construct_utf8_string(OSSL_ENCODER_PARAM_CIPHER,
34                                          (void *)cipher_name, 0);
35     params[1] =
36         OSSL_PARAM_construct_utf8_string(OSSL_ENCODER_PARAM_PROPERTIES,
37                                          (void *)propquery, 0);
38 
39     return OSSL_ENCODER_CTX_set_params(ctx, params);
40 }
41 
OSSL_ENCODER_CTX_set_passphrase(OSSL_ENCODER_CTX * ctx,const unsigned char * kstr,size_t klen)42 int OSSL_ENCODER_CTX_set_passphrase(OSSL_ENCODER_CTX *ctx,
43                                     const unsigned char *kstr,
44                                     size_t klen)
45 {
46     return ossl_pw_set_passphrase(&ctx->pwdata, kstr, klen);
47 }
48 
OSSL_ENCODER_CTX_set_passphrase_ui(OSSL_ENCODER_CTX * ctx,const UI_METHOD * ui_method,void * ui_data)49 int OSSL_ENCODER_CTX_set_passphrase_ui(OSSL_ENCODER_CTX *ctx,
50                                        const UI_METHOD *ui_method,
51                                        void *ui_data)
52 {
53     return ossl_pw_set_ui_method(&ctx->pwdata, ui_method, ui_data);
54 }
55 
OSSL_ENCODER_CTX_set_pem_password_cb(OSSL_ENCODER_CTX * ctx,pem_password_cb * cb,void * cbarg)56 int OSSL_ENCODER_CTX_set_pem_password_cb(OSSL_ENCODER_CTX *ctx,
57                                          pem_password_cb *cb, void *cbarg)
58 {
59     return ossl_pw_set_pem_password_cb(&ctx->pwdata, cb, cbarg);
60 }
61 
OSSL_ENCODER_CTX_set_passphrase_cb(OSSL_ENCODER_CTX * ctx,OSSL_PASSPHRASE_CALLBACK * cb,void * cbarg)62 int OSSL_ENCODER_CTX_set_passphrase_cb(OSSL_ENCODER_CTX *ctx,
63                                        OSSL_PASSPHRASE_CALLBACK *cb,
64                                        void *cbarg)
65 {
66     return ossl_pw_set_ossl_passphrase_cb(&ctx->pwdata, cb, cbarg);
67 }
68 
69 /*
70  * Support for OSSL_ENCODER_CTX_new_for_type:
71  * finding a suitable encoder
72  */
73 
74 struct collected_encoder_st {
75     STACK_OF(OPENSSL_CSTRING) *names;
76     const char *output_structure;
77     const char *output_type;
78 
79     const OSSL_PROVIDER *keymgmt_prov;
80     OSSL_ENCODER_CTX *ctx;
81     unsigned int flag_find_same_provider:1;
82 
83     int error_occurred;
84 };
85 
collect_encoder(OSSL_ENCODER * encoder,void * arg)86 static void collect_encoder(OSSL_ENCODER *encoder, void *arg)
87 {
88     struct collected_encoder_st *data = arg;
89     size_t i, end_i;
90 
91     if (data->error_occurred)
92         return;
93 
94     data->error_occurred = 1;     /* Assume the worst */
95 
96     if (data->names == NULL)
97         return;
98 
99     end_i = sk_OPENSSL_CSTRING_num(data->names);
100     for (i = 0; i < end_i; i++) {
101         const char *name = sk_OPENSSL_CSTRING_value(data->names, i);
102         const OSSL_PROVIDER *prov = OSSL_ENCODER_get0_provider(encoder);
103         void *provctx = OSSL_PROVIDER_get0_provider_ctx(prov);
104 
105         /*
106          * collect_encoder() is called in two passes, one where the encoders
107          * from the same provider as the keymgmt are looked up, and one where
108          * the other encoders are looked up.  |data->flag_find_same_provider|
109          * tells us which pass we're in.
110          */
111         if ((data->keymgmt_prov == prov) != data->flag_find_same_provider)
112             continue;
113 
114         if (!OSSL_ENCODER_is_a(encoder, name)
115             || (encoder->does_selection != NULL
116                 && !encoder->does_selection(provctx, data->ctx->selection))
117             || (data->keymgmt_prov != prov
118                 && encoder->import_object == NULL))
119             continue;
120 
121         /* Only add each encoder implementation once */
122         if (OSSL_ENCODER_CTX_add_encoder(data->ctx, encoder))
123             break;
124     }
125 
126     data->error_occurred = 0;         /* All is good now */
127 }
128 
129 struct collected_names_st {
130     STACK_OF(OPENSSL_CSTRING) *names;
131     unsigned int error_occurred:1;
132 };
133 
collect_name(const char * name,void * arg)134 static void collect_name(const char *name, void *arg)
135 {
136     struct collected_names_st *data = arg;
137 
138     if (data->error_occurred)
139         return;
140 
141     data->error_occurred = 1;         /* Assume the worst */
142 
143     if (sk_OPENSSL_CSTRING_push(data->names, name) <= 0)
144         return;
145 
146     data->error_occurred = 0;         /* All is good now */
147 }
148 
149 /*
150  * Support for OSSL_ENCODER_to_bio:
151  * writing callback for the OSSL_PARAM (the implementation doesn't have
152  * intimate knowledge of the provider side object)
153  */
154 
155 struct construct_data_st {
156     const EVP_PKEY *pk;
157     int selection;
158 
159     OSSL_ENCODER_INSTANCE *encoder_inst;
160     const void *obj;
161     void *constructed_obj;
162 };
163 
encoder_import_cb(const OSSL_PARAM params[],void * arg)164 static int encoder_import_cb(const OSSL_PARAM params[], void *arg)
165 {
166     struct construct_data_st *construct_data = arg;
167     OSSL_ENCODER_INSTANCE *encoder_inst = construct_data->encoder_inst;
168     OSSL_ENCODER *encoder = OSSL_ENCODER_INSTANCE_get_encoder(encoder_inst);
169     void *encoderctx = OSSL_ENCODER_INSTANCE_get_encoder_ctx(encoder_inst);
170 
171     construct_data->constructed_obj =
172         encoder->import_object(encoderctx, construct_data->selection, params);
173 
174     return (construct_data->constructed_obj != NULL);
175 }
176 
177 static const void *
encoder_construct_pkey(OSSL_ENCODER_INSTANCE * encoder_inst,void * arg)178 encoder_construct_pkey(OSSL_ENCODER_INSTANCE *encoder_inst, void *arg)
179 {
180     struct construct_data_st *data = arg;
181 
182     if (data->obj == NULL) {
183         OSSL_ENCODER *encoder =
184             OSSL_ENCODER_INSTANCE_get_encoder(encoder_inst);
185         const EVP_PKEY *pk = data->pk;
186         const OSSL_PROVIDER *k_prov = EVP_KEYMGMT_get0_provider(pk->keymgmt);
187         const OSSL_PROVIDER *e_prov = OSSL_ENCODER_get0_provider(encoder);
188 
189         if (k_prov != e_prov) {
190             data->encoder_inst = encoder_inst;
191 
192             if (!evp_keymgmt_export(pk->keymgmt, pk->keydata, data->selection,
193                                     &encoder_import_cb, data))
194                 return NULL;
195             data->obj = data->constructed_obj;
196         } else {
197             data->obj = pk->keydata;
198         }
199     }
200 
201     return data->obj;
202 }
203 
encoder_destruct_pkey(void * arg)204 static void encoder_destruct_pkey(void *arg)
205 {
206     struct construct_data_st *data = arg;
207 
208     if (data->encoder_inst != NULL) {
209         OSSL_ENCODER *encoder =
210             OSSL_ENCODER_INSTANCE_get_encoder(data->encoder_inst);
211 
212         encoder->free_object(data->constructed_obj);
213     }
214     data->constructed_obj = NULL;
215 }
216 
217 /*
218  * OSSL_ENCODER_CTX_new_for_pkey() returns a ctx with no encoder if
219  * it couldn't find a suitable encoder.  This allows a caller to detect if
220  * a suitable encoder was found, with OSSL_ENCODER_CTX_get_num_encoder(),
221  * and to use fallback methods if the result is NULL.
222  */
ossl_encoder_ctx_setup_for_pkey(OSSL_ENCODER_CTX * ctx,const EVP_PKEY * pkey,int selection,const char * propquery)223 static int ossl_encoder_ctx_setup_for_pkey(OSSL_ENCODER_CTX *ctx,
224                                            const EVP_PKEY *pkey,
225                                            int selection,
226                                            const char *propquery)
227 {
228     struct construct_data_st *data = NULL;
229     const OSSL_PROVIDER *prov = NULL;
230     OSSL_LIB_CTX *libctx = NULL;
231     int ok = 0;
232 
233     if (!ossl_assert(ctx != NULL) || !ossl_assert(pkey != NULL)) {
234         ERR_raise(ERR_LIB_OSSL_ENCODER, ERR_R_PASSED_NULL_PARAMETER);
235         return 0;
236     }
237 
238     if (evp_pkey_is_provided(pkey)) {
239         prov = EVP_KEYMGMT_get0_provider(pkey->keymgmt);
240         libctx = ossl_provider_libctx(prov);
241     }
242 
243     if (pkey->keymgmt != NULL) {
244         struct collected_encoder_st encoder_data;
245         struct collected_names_st keymgmt_data;
246 
247         if ((data = OPENSSL_zalloc(sizeof(*data))) == NULL) {
248             ERR_raise(ERR_LIB_OSSL_ENCODER, ERR_R_MALLOC_FAILURE);
249             goto err;
250         }
251 
252         /*
253          * Select the first encoder implementations in two steps.
254          * First, collect the keymgmt names, then the encoders that match.
255          */
256         keymgmt_data.names = sk_OPENSSL_CSTRING_new_null();
257         keymgmt_data.error_occurred = 0;
258         EVP_KEYMGMT_names_do_all(pkey->keymgmt, collect_name, &keymgmt_data);
259         if (keymgmt_data.error_occurred) {
260             sk_OPENSSL_CSTRING_free(keymgmt_data.names);
261             goto err;
262         }
263 
264         encoder_data.names = keymgmt_data.names;
265         encoder_data.output_type = ctx->output_type;
266         encoder_data.output_structure = ctx->output_structure;
267         encoder_data.error_occurred = 0;
268         encoder_data.keymgmt_prov = prov;
269         encoder_data.ctx = ctx;
270 
271         /*
272          * Place the encoders with the a different provider as the keymgmt
273          * last (the chain is processed in reverse order)
274          */
275         encoder_data.flag_find_same_provider = 0;
276         OSSL_ENCODER_do_all_provided(libctx, collect_encoder, &encoder_data);
277 
278         /*
279          * Place the encoders with the same provider as the keymgmt first
280          * (the chain is processed in reverse order)
281          */
282         encoder_data.flag_find_same_provider = 1;
283         OSSL_ENCODER_do_all_provided(libctx, collect_encoder, &encoder_data);
284 
285         sk_OPENSSL_CSTRING_free(keymgmt_data.names);
286         if (encoder_data.error_occurred) {
287             ERR_raise(ERR_LIB_OSSL_ENCODER, ERR_R_MALLOC_FAILURE);
288             goto err;
289         }
290     }
291 
292     if (data != NULL && OSSL_ENCODER_CTX_get_num_encoders(ctx) != 0) {
293         if (!OSSL_ENCODER_CTX_set_construct(ctx, encoder_construct_pkey)
294             || !OSSL_ENCODER_CTX_set_construct_data(ctx, data)
295             || !OSSL_ENCODER_CTX_set_cleanup(ctx, encoder_destruct_pkey))
296             goto err;
297 
298         data->pk = pkey;
299         data->selection = selection;
300 
301         data = NULL;             /* Avoid it being freed */
302     }
303 
304     ok = 1;
305  err:
306     if (data != NULL) {
307         OSSL_ENCODER_CTX_set_construct_data(ctx, NULL);
308         OPENSSL_free(data);
309     }
310     return ok;
311 }
312 
OSSL_ENCODER_CTX_new_for_pkey(const EVP_PKEY * pkey,int selection,const char * output_type,const char * output_struct,const char * propquery)313 OSSL_ENCODER_CTX *OSSL_ENCODER_CTX_new_for_pkey(const EVP_PKEY *pkey,
314                                                 int selection,
315                                                 const char *output_type,
316                                                 const char *output_struct,
317                                                 const char *propquery)
318 {
319     OSSL_ENCODER_CTX *ctx = NULL;
320     OSSL_LIB_CTX *libctx = NULL;
321 
322     if (pkey == NULL) {
323         ERR_raise(ERR_LIB_OSSL_ENCODER, ERR_R_PASSED_NULL_PARAMETER);
324         return NULL;
325     }
326 
327     if (!evp_pkey_is_assigned(pkey)) {
328         ERR_raise_data(ERR_LIB_OSSL_ENCODER, ERR_R_PASSED_INVALID_ARGUMENT,
329                        "The passed EVP_PKEY must be assigned a key");
330         return NULL;
331     }
332 
333     if ((ctx = OSSL_ENCODER_CTX_new()) == NULL) {
334         ERR_raise(ERR_LIB_OSSL_ENCODER, ERR_R_MALLOC_FAILURE);
335         return NULL;
336     }
337 
338     if (evp_pkey_is_provided(pkey)) {
339         const OSSL_PROVIDER *prov = EVP_KEYMGMT_get0_provider(pkey->keymgmt);
340 
341         libctx = ossl_provider_libctx(prov);
342     }
343 
344     OSSL_TRACE_BEGIN(ENCODER) {
345         BIO_printf(trc_out,
346                    "(ctx %p) Looking for %s encoders with selection %d\n",
347                    (void *)ctx, EVP_PKEY_get0_type_name(pkey), selection);
348         BIO_printf(trc_out, "    output type: %s, output structure: %s\n",
349                    output_type, output_struct);
350     } OSSL_TRACE_END(ENCODER);
351 
352     if (OSSL_ENCODER_CTX_set_output_type(ctx, output_type)
353         && (output_struct == NULL
354             || OSSL_ENCODER_CTX_set_output_structure(ctx, output_struct))
355         && OSSL_ENCODER_CTX_set_selection(ctx, selection)
356         && ossl_encoder_ctx_setup_for_pkey(ctx, pkey, selection, propquery)
357         && OSSL_ENCODER_CTX_add_extra(ctx, libctx, propquery)) {
358         OSSL_PARAM params[2] = { OSSL_PARAM_END, OSSL_PARAM_END };
359         int save_parameters = pkey->save_parameters;
360 
361         params[0] = OSSL_PARAM_construct_int(OSSL_ENCODER_PARAM_SAVE_PARAMETERS,
362                                              &save_parameters);
363         /* ignoring error as this is only auxiliary parameter */
364         (void)OSSL_ENCODER_CTX_set_params(ctx, params);
365 
366         OSSL_TRACE_BEGIN(ENCODER) {
367             BIO_printf(trc_out, "(ctx %p) Got %d encoders\n",
368                        (void *)ctx, OSSL_ENCODER_CTX_get_num_encoders(ctx));
369         } OSSL_TRACE_END(ENCODER);
370         return ctx;
371     }
372 
373     OSSL_ENCODER_CTX_free(ctx);
374     return NULL;
375 }
376