xref: /freebsd/crypto/openssl/crypto/encode_decode/decoder_lib.c (revision e7be843b4a162e68651d3911f0357ed464915629)
1 /*
2  * Copyright 2020-2025 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/bio.h>
12 #include <openssl/params.h>
13 #include <openssl/provider.h>
14 #include <openssl/evperr.h>
15 #include <openssl/ecerr.h>
16 #include <openssl/pkcs12err.h>
17 #include <openssl/x509err.h>
18 #include <openssl/trace.h>
19 #include "internal/bio.h"
20 #include "internal/provider.h"
21 #include "internal/namemap.h"
22 #include "crypto/decoder.h"
23 #include "encoder_local.h"
24 #include "internal/e_os.h"
25 
26 struct decoder_process_data_st {
27     OSSL_DECODER_CTX *ctx;
28 
29     /* Current BIO */
30     BIO *bio;
31 
32     /* Index of the current decoder instance to be processed */
33     size_t current_decoder_inst_index;
34     /* For tracing, count recursion level */
35     size_t recursion;
36 
37     /*-
38      * Flags
39      */
40     unsigned int flag_next_level_called : 1;
41     unsigned int flag_construct_called : 1;
42     unsigned int flag_input_structure_checked : 1;
43 };
44 
45 static int decoder_process(const OSSL_PARAM params[], void *arg);
46 
OSSL_DECODER_from_bio(OSSL_DECODER_CTX * ctx,BIO * in)47 int OSSL_DECODER_from_bio(OSSL_DECODER_CTX *ctx, BIO *in)
48 {
49     struct decoder_process_data_st data;
50     int ok = 0;
51     BIO *new_bio = NULL;
52     unsigned long lasterr;
53 
54     if (in == NULL) {
55         ERR_raise(ERR_LIB_OSSL_DECODER, ERR_R_PASSED_NULL_PARAMETER);
56         return 0;
57     }
58 
59     if (OSSL_DECODER_CTX_get_num_decoders(ctx) == 0) {
60         ERR_raise_data(ERR_LIB_OSSL_DECODER, OSSL_DECODER_R_DECODER_NOT_FOUND,
61                        "No decoders were found. For standard decoders you need "
62                        "at least one of the default or base providers "
63                        "available. Did you forget to load them?");
64         return 0;
65     }
66 
67     lasterr = ERR_peek_last_error();
68 
69     if (BIO_tell(in) < 0) {
70         new_bio = BIO_new(BIO_f_readbuffer());
71         if (new_bio == NULL)
72             return 0;
73         in = BIO_push(new_bio, in);
74     }
75     memset(&data, 0, sizeof(data));
76     data.ctx = ctx;
77     data.bio = in;
78 
79     /* Enable passphrase caching */
80     (void)ossl_pw_enable_passphrase_caching(&ctx->pwdata);
81 
82     ok = decoder_process(NULL, &data);
83 
84     if (!data.flag_construct_called) {
85         const char *spaces
86             = ctx->start_input_type != NULL && ctx->input_structure != NULL
87             ? " " : "";
88         const char *input_type_label
89             = ctx->start_input_type != NULL ? "Input type: " : "";
90         const char *input_structure_label
91             = ctx->input_structure != NULL ? "Input structure: " : "";
92         const char *comma
93             = ctx->start_input_type != NULL && ctx->input_structure != NULL
94             ? ", " : "";
95         const char *input_type
96             = ctx->start_input_type != NULL ? ctx->start_input_type : "";
97         const char *input_structure
98             = ctx->input_structure != NULL ? ctx->input_structure : "";
99 
100         if (ERR_peek_last_error() == lasterr || ERR_peek_error() == 0)
101             /* Prevent spurious decoding error but add at least something */
102             ERR_raise_data(ERR_LIB_OSSL_DECODER, ERR_R_UNSUPPORTED,
103                            "No supported data to decode. %s%s%s%s%s%s",
104                            spaces, input_type_label, input_type, comma,
105                            input_structure_label, input_structure);
106         ok = 0;
107     }
108 
109     /* Clear any internally cached passphrase */
110     (void)ossl_pw_clear_passphrase_cache(&ctx->pwdata);
111 
112     if (new_bio != NULL) {
113         BIO_pop(new_bio);
114         BIO_free(new_bio);
115     }
116     return ok;
117 }
118 
119 #ifndef OPENSSL_NO_STDIO
bio_from_file(FILE * fp)120 static BIO *bio_from_file(FILE *fp)
121 {
122     BIO *b;
123 
124     if ((b = BIO_new(BIO_s_file())) == NULL) {
125         ERR_raise(ERR_LIB_OSSL_DECODER, ERR_R_BIO_LIB);
126         return NULL;
127     }
128     BIO_set_fp(b, fp, BIO_NOCLOSE);
129     return b;
130 }
131 
OSSL_DECODER_from_fp(OSSL_DECODER_CTX * ctx,FILE * fp)132 int OSSL_DECODER_from_fp(OSSL_DECODER_CTX *ctx, FILE *fp)
133 {
134     BIO *b = bio_from_file(fp);
135     int ret = 0;
136 
137     if (b != NULL)
138         ret = OSSL_DECODER_from_bio(ctx, b);
139 
140     BIO_free(b);
141     return ret;
142 }
143 #endif
144 
OSSL_DECODER_from_data(OSSL_DECODER_CTX * ctx,const unsigned char ** pdata,size_t * pdata_len)145 int OSSL_DECODER_from_data(OSSL_DECODER_CTX *ctx, const unsigned char **pdata,
146                            size_t *pdata_len)
147 {
148     BIO *membio;
149     int ret = 0;
150 
151     if (pdata == NULL || *pdata == NULL || pdata_len == NULL) {
152         ERR_raise(ERR_LIB_OSSL_DECODER, ERR_R_PASSED_NULL_PARAMETER);
153         return 0;
154     }
155 
156     membio = BIO_new_mem_buf(*pdata, (int)*pdata_len);
157     if (OSSL_DECODER_from_bio(ctx, membio)) {
158         *pdata_len = (size_t)BIO_get_mem_data(membio, pdata);
159         ret = 1;
160     }
161     BIO_free(membio);
162 
163     return ret;
164 }
165 
OSSL_DECODER_CTX_set_selection(OSSL_DECODER_CTX * ctx,int selection)166 int OSSL_DECODER_CTX_set_selection(OSSL_DECODER_CTX *ctx, int selection)
167 {
168     if (!ossl_assert(ctx != NULL)) {
169         ERR_raise(ERR_LIB_OSSL_DECODER, ERR_R_PASSED_NULL_PARAMETER);
170         return 0;
171     }
172 
173     /*
174      * 0 is a valid selection, and means that the caller leaves
175      * it to code to discover what the selection is.
176      */
177     ctx->selection = selection;
178     return 1;
179 }
180 
OSSL_DECODER_CTX_set_input_type(OSSL_DECODER_CTX * ctx,const char * input_type)181 int OSSL_DECODER_CTX_set_input_type(OSSL_DECODER_CTX *ctx,
182                                     const char *input_type)
183 {
184     if (!ossl_assert(ctx != NULL)) {
185         ERR_raise(ERR_LIB_OSSL_DECODER, ERR_R_PASSED_NULL_PARAMETER);
186         return 0;
187     }
188 
189     /*
190      * NULL is a valid starting input type, and means that the caller leaves
191      * it to code to discover what the starting input type is.
192      */
193     ctx->start_input_type = input_type;
194     return 1;
195 }
196 
OSSL_DECODER_CTX_set_input_structure(OSSL_DECODER_CTX * ctx,const char * input_structure)197 int OSSL_DECODER_CTX_set_input_structure(OSSL_DECODER_CTX *ctx,
198                                          const char *input_structure)
199 {
200     if (!ossl_assert(ctx != NULL)) {
201         ERR_raise(ERR_LIB_OSSL_DECODER, ERR_R_PASSED_NULL_PARAMETER);
202         return 0;
203     }
204 
205     /*
206      * NULL is a valid starting input structure, and means that the caller
207      * leaves it to code to discover what the starting input structure is.
208      */
209     ctx->input_structure = input_structure;
210     return 1;
211 }
212 
213 OSSL_DECODER_INSTANCE *
ossl_decoder_instance_new_forprov(OSSL_DECODER * decoder,void * provctx,const char * input_structure)214 ossl_decoder_instance_new_forprov(OSSL_DECODER *decoder, void *provctx,
215                                   const char *input_structure)
216 {
217     void *decoderctx;
218 
219     if (!ossl_assert(decoder != NULL)) {
220         ERR_raise(ERR_LIB_OSSL_DECODER, ERR_R_PASSED_NULL_PARAMETER);
221         return 0;
222     }
223 
224     decoderctx = decoder->newctx(provctx);
225     if (decoderctx == NULL)
226         return 0;
227     if (input_structure != NULL && decoder->set_ctx_params != NULL) {
228         OSSL_PARAM params[] = { OSSL_PARAM_END, OSSL_PARAM_END };
229 
230         params[0] =
231             OSSL_PARAM_construct_utf8_string(OSSL_OBJECT_PARAM_DATA_STRUCTURE,
232                                              (char *)input_structure, 0);
233         if (!decoder->set_ctx_params(decoderctx, params)) {
234             decoder->freectx(decoderctx);
235             return 0;
236         }
237     }
238     return ossl_decoder_instance_new(decoder, decoderctx);
239 }
240 
ossl_decoder_instance_new(OSSL_DECODER * decoder,void * decoderctx)241 OSSL_DECODER_INSTANCE *ossl_decoder_instance_new(OSSL_DECODER *decoder,
242                                                  void *decoderctx)
243 {
244     OSSL_DECODER_INSTANCE *decoder_inst = NULL;
245     const OSSL_PROVIDER *prov;
246     OSSL_LIB_CTX *libctx;
247     const OSSL_PROPERTY_LIST *props;
248     const OSSL_PROPERTY_DEFINITION *prop;
249 
250     if (!ossl_assert(decoder != NULL)) {
251         ERR_raise(ERR_LIB_OSSL_DECODER, ERR_R_PASSED_NULL_PARAMETER);
252         return 0;
253     }
254 
255     if ((decoder_inst = OPENSSL_zalloc(sizeof(*decoder_inst))) == NULL)
256         return 0;
257 
258     prov = OSSL_DECODER_get0_provider(decoder);
259     libctx = ossl_provider_libctx(prov);
260     props = ossl_decoder_parsed_properties(decoder);
261     if (props == NULL) {
262         ERR_raise_data(ERR_LIB_OSSL_DECODER, ERR_R_INVALID_PROPERTY_DEFINITION,
263                        "there are no property definitions with decoder %s",
264                        OSSL_DECODER_get0_name(decoder));
265         goto err;
266     }
267 
268     /* The "input" property is mandatory */
269     prop = ossl_property_find_property(props, libctx, "input");
270     decoder_inst->input_type = ossl_property_get_string_value(libctx, prop);
271     decoder_inst->input_type_id = 0;
272     if (decoder_inst->input_type == NULL) {
273         ERR_raise_data(ERR_LIB_OSSL_DECODER, ERR_R_INVALID_PROPERTY_DEFINITION,
274                        "the mandatory 'input' property is missing "
275                        "for decoder %s (properties: %s)",
276                        OSSL_DECODER_get0_name(decoder),
277                        OSSL_DECODER_get0_properties(decoder));
278         goto err;
279     }
280 
281     /* The "structure" property is optional */
282     prop = ossl_property_find_property(props, libctx, "structure");
283     if (prop != NULL) {
284         decoder_inst->input_structure
285             = ossl_property_get_string_value(libctx, prop);
286     }
287 
288     if (!OSSL_DECODER_up_ref(decoder)) {
289         ERR_raise(ERR_LIB_OSSL_DECODER, ERR_R_INTERNAL_ERROR);
290         goto err;
291     }
292     decoder_inst->decoder = decoder;
293     decoder_inst->decoderctx = decoderctx;
294     return decoder_inst;
295  err:
296     ossl_decoder_instance_free(decoder_inst);
297     return NULL;
298 }
299 
ossl_decoder_instance_free(OSSL_DECODER_INSTANCE * decoder_inst)300 void ossl_decoder_instance_free(OSSL_DECODER_INSTANCE *decoder_inst)
301 {
302     if (decoder_inst != NULL) {
303         if (decoder_inst->decoder != NULL)
304             decoder_inst->decoder->freectx(decoder_inst->decoderctx);
305         decoder_inst->decoderctx = NULL;
306         OSSL_DECODER_free(decoder_inst->decoder);
307         decoder_inst->decoder = NULL;
308         OPENSSL_free(decoder_inst);
309     }
310 }
311 
ossl_decoder_instance_dup(const OSSL_DECODER_INSTANCE * src)312 OSSL_DECODER_INSTANCE *ossl_decoder_instance_dup(const OSSL_DECODER_INSTANCE *src)
313 {
314     OSSL_DECODER_INSTANCE *dest;
315     const OSSL_PROVIDER *prov;
316     void *provctx;
317 
318     if ((dest = OPENSSL_zalloc(sizeof(*dest))) == NULL)
319         return NULL;
320 
321     *dest = *src;
322     if (!OSSL_DECODER_up_ref(dest->decoder)) {
323         ERR_raise(ERR_LIB_OSSL_DECODER, ERR_R_INTERNAL_ERROR);
324         goto err;
325     }
326     prov = OSSL_DECODER_get0_provider(dest->decoder);
327     provctx = OSSL_PROVIDER_get0_provider_ctx(prov);
328 
329     dest->decoderctx = dest->decoder->newctx(provctx);
330     if (dest->decoderctx == NULL) {
331         ERR_raise(ERR_LIB_OSSL_DECODER, ERR_R_INTERNAL_ERROR);
332         OSSL_DECODER_free(dest->decoder);
333         goto err;
334     }
335 
336     return dest;
337 
338  err:
339     OPENSSL_free(dest);
340     return NULL;
341 }
342 
ossl_decoder_ctx_set_harderr(OSSL_DECODER_CTX * ctx)343 void ossl_decoder_ctx_set_harderr(OSSL_DECODER_CTX *ctx)
344 {
345     ctx->harderr = 1;
346 }
347 
ossl_decoder_ctx_get_harderr(const OSSL_DECODER_CTX * ctx)348 int ossl_decoder_ctx_get_harderr(const OSSL_DECODER_CTX *ctx)
349 {
350     return ctx->harderr;
351 }
352 
ossl_decoder_ctx_add_decoder_inst(OSSL_DECODER_CTX * ctx,OSSL_DECODER_INSTANCE * di)353 int ossl_decoder_ctx_add_decoder_inst(OSSL_DECODER_CTX *ctx,
354                                       OSSL_DECODER_INSTANCE *di)
355 {
356     int ok;
357 
358     if (ctx->decoder_insts == NULL
359         && (ctx->decoder_insts =
360             sk_OSSL_DECODER_INSTANCE_new_null()) == NULL) {
361         ERR_raise(ERR_LIB_OSSL_DECODER, ERR_R_CRYPTO_LIB);
362         return 0;
363     }
364 
365     ok = (sk_OSSL_DECODER_INSTANCE_push(ctx->decoder_insts, di) > 0);
366     if (ok) {
367         OSSL_TRACE_BEGIN(DECODER) {
368             BIO_printf(trc_out,
369                        "(ctx %p) Added decoder instance %p for decoder %p\n"
370                        "    %s with %s\n",
371                        (void *)ctx, (void *)di, (void *)di->decoder,
372                        OSSL_DECODER_get0_name(di->decoder),
373                        OSSL_DECODER_get0_properties(di->decoder));
374         } OSSL_TRACE_END(DECODER);
375     }
376     return ok;
377 }
378 
OSSL_DECODER_CTX_add_decoder(OSSL_DECODER_CTX * ctx,OSSL_DECODER * decoder)379 int OSSL_DECODER_CTX_add_decoder(OSSL_DECODER_CTX *ctx, OSSL_DECODER *decoder)
380 {
381     OSSL_DECODER_INSTANCE *decoder_inst = NULL;
382     const OSSL_PROVIDER *prov = NULL;
383     void *decoderctx = NULL;
384     void *provctx = NULL;
385 
386     if (!ossl_assert(ctx != NULL) || !ossl_assert(decoder != NULL)) {
387         ERR_raise(ERR_LIB_OSSL_DECODER, ERR_R_PASSED_NULL_PARAMETER);
388         return 0;
389     }
390 
391     prov = OSSL_DECODER_get0_provider(decoder);
392     provctx = OSSL_PROVIDER_get0_provider_ctx(prov);
393 
394     if ((decoderctx = decoder->newctx(provctx)) == NULL
395         || (decoder_inst =
396             ossl_decoder_instance_new(decoder, decoderctx)) == NULL)
397         goto err;
398     /* Avoid double free of decoderctx on further errors */
399     decoderctx = NULL;
400 
401     if (!ossl_decoder_ctx_add_decoder_inst(ctx, decoder_inst))
402         goto err;
403 
404     return 1;
405  err:
406     ossl_decoder_instance_free(decoder_inst);
407     if (decoderctx != NULL)
408         decoder->freectx(decoderctx);
409     return 0;
410 }
411 
412 struct collect_extra_decoder_data_st {
413     OSSL_DECODER_CTX *ctx;
414     const char *output_type;
415     int output_type_id;
416 
417     /*
418      * 0 to check that the decoder's input type is the same as the decoder name
419      * 1 to check that the decoder's input type differs from the decoder name
420      */
421     enum { IS_SAME = 0, IS_DIFFERENT = 1 } type_check;
422     size_t w_prev_start, w_prev_end; /* "previous" decoders */
423     size_t w_new_start, w_new_end;   /* "new" decoders */
424 };
425 
DEFINE_STACK_OF(OSSL_DECODER)426 DEFINE_STACK_OF(OSSL_DECODER)
427 
428 static void collect_all_decoders(OSSL_DECODER *decoder, void *arg)
429 {
430     STACK_OF(OSSL_DECODER) *skdecoders = arg;
431 
432     if (OSSL_DECODER_up_ref(decoder)
433             && !sk_OSSL_DECODER_push(skdecoders, decoder))
434         OSSL_DECODER_free(decoder);
435 }
436 
collect_extra_decoder(OSSL_DECODER * decoder,void * arg)437 static void collect_extra_decoder(OSSL_DECODER *decoder, void *arg)
438 {
439     struct collect_extra_decoder_data_st *data = arg;
440     size_t j;
441     const OSSL_PROVIDER *prov = OSSL_DECODER_get0_provider(decoder);
442     void *provctx = OSSL_PROVIDER_get0_provider_ctx(prov);
443 
444     if (ossl_decoder_fast_is_a(decoder, data->output_type, &data->output_type_id)) {
445         void *decoderctx = NULL;
446         OSSL_DECODER_INSTANCE *di = NULL;
447 
448         OSSL_TRACE_BEGIN(DECODER) {
449             BIO_printf(trc_out,
450                        "(ctx %p) [%d] Checking out decoder %p:\n"
451                        "    %s with %s\n",
452                        (void *)data->ctx, data->type_check, (void *)decoder,
453                        OSSL_DECODER_get0_name(decoder),
454                        OSSL_DECODER_get0_properties(decoder));
455         } OSSL_TRACE_END(DECODER);
456 
457         /*
458          * Check that we don't already have this decoder in our stack,
459          * starting with the previous windows but also looking at what
460          * we have added in the current window.
461          */
462         for (j = data->w_prev_start; j < data->w_new_end; j++) {
463             OSSL_DECODER_INSTANCE *check_inst =
464                 sk_OSSL_DECODER_INSTANCE_value(data->ctx->decoder_insts, j);
465 
466             if (decoder->base.algodef == check_inst->decoder->base.algodef) {
467                 /* We found it, so don't do anything more */
468                 OSSL_TRACE_BEGIN(DECODER) {
469                     BIO_printf(trc_out,
470                                "    REJECTED: already exists in the chain\n");
471                 } OSSL_TRACE_END(DECODER);
472                 return;
473             }
474         }
475 
476         if ((decoderctx = decoder->newctx(provctx)) == NULL)
477             return;
478 
479         if (decoder->set_ctx_params != NULL
480             && data->ctx->input_structure != NULL) {
481             OSSL_PARAM params[] = { OSSL_PARAM_END, OSSL_PARAM_END };
482             const char *str = data->ctx->input_structure;
483 
484             params[0] =
485                 OSSL_PARAM_construct_utf8_string(OSSL_OBJECT_PARAM_DATA_STRUCTURE,
486                                                  (char *)str, 0);
487             if (!decoder->set_ctx_params(decoderctx, params)) {
488                 decoder->freectx(decoderctx);
489                 return;
490             }
491         }
492 
493         if ((di = ossl_decoder_instance_new(decoder, decoderctx)) == NULL) {
494             decoder->freectx(decoderctx);
495             return;
496         }
497 
498         switch (data->type_check) {
499         case IS_SAME:
500             /* If it differs, this is not a decoder to add for now. */
501             if (!ossl_decoder_fast_is_a(decoder,
502                                         OSSL_DECODER_INSTANCE_get_input_type(di),
503                                         &di->input_type_id)) {
504                 ossl_decoder_instance_free(di);
505                 OSSL_TRACE_BEGIN(DECODER) {
506                     BIO_printf(trc_out,
507                                "    REJECTED: input type doesn't match output type\n");
508                 } OSSL_TRACE_END(DECODER);
509                 return;
510             }
511             break;
512         case IS_DIFFERENT:
513             /* If it's the same, this is not a decoder to add for now. */
514             if (ossl_decoder_fast_is_a(decoder,
515                                        OSSL_DECODER_INSTANCE_get_input_type(di),
516                                        &di->input_type_id)) {
517                 ossl_decoder_instance_free(di);
518                 OSSL_TRACE_BEGIN(DECODER) {
519                     BIO_printf(trc_out,
520                                "    REJECTED: input type matches output type\n");
521                 } OSSL_TRACE_END(DECODER);
522                 return;
523             }
524             break;
525         }
526 
527         /*
528          * Apart from keeping w_new_end up to date, We don't care about
529          * errors here.  If it doesn't collect, then it doesn't...
530          */
531         if (!ossl_decoder_ctx_add_decoder_inst(data->ctx, di)) {
532             ossl_decoder_instance_free(di);
533             return;
534         }
535 
536         data->w_new_end++;
537     }
538 }
539 
OSSL_DECODER_CTX_add_extra(OSSL_DECODER_CTX * ctx,OSSL_LIB_CTX * libctx,const char * propq)540 int OSSL_DECODER_CTX_add_extra(OSSL_DECODER_CTX *ctx,
541                                OSSL_LIB_CTX *libctx, const char *propq)
542 {
543     /*
544      * This function goes through existing decoder methods in
545      * |ctx->decoder_insts|, and tries to fetch new decoders that produce
546      * what the existing ones want as input, and push those newly fetched
547      * decoders on top of the same stack.
548      * Then it does the same again, but looping over the newly fetched
549      * decoders, until there are no more decoders to be fetched, or
550      * when we have done this 10 times.
551      *
552      * we do this with sliding windows on the stack by keeping track of indexes
553      * and of the end.
554      *
555      * +----------------+
556      * |   DER to RSA   | <--- w_prev_start
557      * +----------------+
558      * |   DER to DSA   |
559      * +----------------+
560      * |   DER to DH    |
561      * +----------------+
562      * |   PEM to DER   | <--- w_prev_end, w_new_start
563      * +----------------+
564      *                    <--- w_new_end
565      */
566     struct collect_extra_decoder_data_st data;
567     size_t depth = 0; /* Counts the number of iterations */
568     size_t count; /* Calculates how many were added in each iteration */
569     size_t numdecoders;
570     STACK_OF(OSSL_DECODER) *skdecoders;
571 
572     if (!ossl_assert(ctx != NULL)) {
573         ERR_raise(ERR_LIB_OSSL_DECODER, ERR_R_PASSED_NULL_PARAMETER);
574         return 0;
575     }
576 
577     /*
578      * If there is no stack of OSSL_DECODER_INSTANCE, we have nothing
579      * more to add.  That's fine.
580      */
581     if (ctx->decoder_insts == NULL)
582         return 1;
583 
584     OSSL_TRACE_BEGIN(DECODER) {
585         BIO_printf(trc_out, "(ctx %p) Looking for extra decoders\n",
586                    (void *)ctx);
587     } OSSL_TRACE_END(DECODER);
588 
589 
590     skdecoders = sk_OSSL_DECODER_new_null();
591     if (skdecoders == NULL) {
592         ERR_raise(ERR_LIB_OSSL_DECODER, ERR_R_CRYPTO_LIB);
593         return 0;
594     }
595     OSSL_DECODER_do_all_provided(libctx, collect_all_decoders, skdecoders);
596     numdecoders = sk_OSSL_DECODER_num(skdecoders);
597 
598     memset(&data, 0, sizeof(data));
599     data.ctx = ctx;
600     data.w_prev_start = 0;
601     data.w_prev_end = sk_OSSL_DECODER_INSTANCE_num(ctx->decoder_insts);
602     do {
603         size_t i, j;
604 
605         data.w_new_start = data.w_new_end = data.w_prev_end;
606 
607         /*
608          * Two iterations:
609          * 0.  All decoders that have the same name as their input type.
610          *     This allows for decoders that unwrap some data in a specific
611          *     encoding, and pass the result on with the same encoding.
612          * 1.  All decoders that a different name than their input type.
613          */
614         for (data.type_check = IS_SAME;
615              data.type_check <= IS_DIFFERENT;
616              data.type_check++) {
617             for (i = data.w_prev_start; i < data.w_prev_end; i++) {
618                 OSSL_DECODER_INSTANCE *decoder_inst =
619                     sk_OSSL_DECODER_INSTANCE_value(ctx->decoder_insts, i);
620 
621                 data.output_type
622                     = OSSL_DECODER_INSTANCE_get_input_type(decoder_inst);
623 
624                 data.output_type_id = 0;
625 
626                 for (j = 0; j < numdecoders; j++)
627                     collect_extra_decoder(sk_OSSL_DECODER_value(skdecoders, j),
628                                           &data);
629             }
630         }
631         /* How many were added in this iteration */
632         count = data.w_new_end - data.w_new_start;
633 
634         /* Slide the "previous decoder" windows */
635         data.w_prev_start = data.w_new_start;
636         data.w_prev_end = data.w_new_end;
637 
638         depth++;
639     } while (count != 0 && depth <= 10);
640 
641     sk_OSSL_DECODER_pop_free(skdecoders, OSSL_DECODER_free);
642     return 1;
643 }
644 
OSSL_DECODER_CTX_get_num_decoders(OSSL_DECODER_CTX * ctx)645 int OSSL_DECODER_CTX_get_num_decoders(OSSL_DECODER_CTX *ctx)
646 {
647     if (ctx == NULL || ctx->decoder_insts == NULL)
648         return 0;
649     return sk_OSSL_DECODER_INSTANCE_num(ctx->decoder_insts);
650 }
651 
OSSL_DECODER_CTX_set_construct(OSSL_DECODER_CTX * ctx,OSSL_DECODER_CONSTRUCT * construct)652 int OSSL_DECODER_CTX_set_construct(OSSL_DECODER_CTX *ctx,
653                                    OSSL_DECODER_CONSTRUCT *construct)
654 {
655     if (!ossl_assert(ctx != NULL)) {
656         ERR_raise(ERR_LIB_OSSL_DECODER, ERR_R_PASSED_NULL_PARAMETER);
657         return 0;
658     }
659     ctx->construct = construct;
660     return 1;
661 }
662 
OSSL_DECODER_CTX_set_construct_data(OSSL_DECODER_CTX * ctx,void * construct_data)663 int OSSL_DECODER_CTX_set_construct_data(OSSL_DECODER_CTX *ctx,
664                                         void *construct_data)
665 {
666     if (!ossl_assert(ctx != NULL)) {
667         ERR_raise(ERR_LIB_OSSL_DECODER, ERR_R_PASSED_NULL_PARAMETER);
668         return 0;
669     }
670     ctx->construct_data = construct_data;
671     return 1;
672 }
673 
OSSL_DECODER_CTX_set_cleanup(OSSL_DECODER_CTX * ctx,OSSL_DECODER_CLEANUP * cleanup)674 int OSSL_DECODER_CTX_set_cleanup(OSSL_DECODER_CTX *ctx,
675                                  OSSL_DECODER_CLEANUP *cleanup)
676 {
677     if (!ossl_assert(ctx != NULL)) {
678         ERR_raise(ERR_LIB_OSSL_DECODER, ERR_R_PASSED_NULL_PARAMETER);
679         return 0;
680     }
681     ctx->cleanup = cleanup;
682     return 1;
683 }
684 
685 OSSL_DECODER_CONSTRUCT *
OSSL_DECODER_CTX_get_construct(OSSL_DECODER_CTX * ctx)686 OSSL_DECODER_CTX_get_construct(OSSL_DECODER_CTX *ctx)
687 {
688     if (ctx == NULL)
689         return NULL;
690     return ctx->construct;
691 }
692 
OSSL_DECODER_CTX_get_construct_data(OSSL_DECODER_CTX * ctx)693 void *OSSL_DECODER_CTX_get_construct_data(OSSL_DECODER_CTX *ctx)
694 {
695     if (ctx == NULL)
696         return NULL;
697     return ctx->construct_data;
698 }
699 
700 OSSL_DECODER_CLEANUP *
OSSL_DECODER_CTX_get_cleanup(OSSL_DECODER_CTX * ctx)701 OSSL_DECODER_CTX_get_cleanup(OSSL_DECODER_CTX *ctx)
702 {
703     if (ctx == NULL)
704         return NULL;
705     return ctx->cleanup;
706 }
707 
OSSL_DECODER_export(OSSL_DECODER_INSTANCE * decoder_inst,void * reference,size_t reference_sz,OSSL_CALLBACK * export_cb,void * export_cbarg)708 int OSSL_DECODER_export(OSSL_DECODER_INSTANCE *decoder_inst,
709                         void *reference, size_t reference_sz,
710                         OSSL_CALLBACK *export_cb, void *export_cbarg)
711 {
712     OSSL_DECODER *decoder = NULL;
713     void *decoderctx = NULL;
714 
715     if (!(ossl_assert(decoder_inst != NULL)
716           && ossl_assert(reference != NULL)
717           && ossl_assert(export_cb != NULL)
718           && ossl_assert(export_cbarg != NULL))) {
719         ERR_raise(ERR_LIB_OSSL_DECODER, ERR_R_PASSED_NULL_PARAMETER);
720         return 0;
721     }
722 
723     decoder = OSSL_DECODER_INSTANCE_get_decoder(decoder_inst);
724     decoderctx = OSSL_DECODER_INSTANCE_get_decoder_ctx(decoder_inst);
725     return decoder->export_object(decoderctx, reference, reference_sz,
726                                   export_cb, export_cbarg);
727 }
728 
729 OSSL_DECODER *
OSSL_DECODER_INSTANCE_get_decoder(OSSL_DECODER_INSTANCE * decoder_inst)730 OSSL_DECODER_INSTANCE_get_decoder(OSSL_DECODER_INSTANCE *decoder_inst)
731 {
732     if (decoder_inst == NULL)
733         return NULL;
734     return decoder_inst->decoder;
735 }
736 
737 void *
OSSL_DECODER_INSTANCE_get_decoder_ctx(OSSL_DECODER_INSTANCE * decoder_inst)738 OSSL_DECODER_INSTANCE_get_decoder_ctx(OSSL_DECODER_INSTANCE *decoder_inst)
739 {
740     if (decoder_inst == NULL)
741         return NULL;
742     return decoder_inst->decoderctx;
743 }
744 
745 const char *
OSSL_DECODER_INSTANCE_get_input_type(OSSL_DECODER_INSTANCE * decoder_inst)746 OSSL_DECODER_INSTANCE_get_input_type(OSSL_DECODER_INSTANCE *decoder_inst)
747 {
748     if (decoder_inst == NULL)
749         return NULL;
750     return decoder_inst->input_type;
751 }
752 
753 const char *
OSSL_DECODER_INSTANCE_get_input_structure(OSSL_DECODER_INSTANCE * decoder_inst,int * was_set)754 OSSL_DECODER_INSTANCE_get_input_structure(OSSL_DECODER_INSTANCE *decoder_inst,
755                                           int *was_set)
756 {
757     if (decoder_inst == NULL)
758         return NULL;
759     *was_set = decoder_inst->flag_input_structure_was_set;
760     return decoder_inst->input_structure;
761 }
762 
decoder_process(const OSSL_PARAM params[],void * arg)763 static int decoder_process(const OSSL_PARAM params[], void *arg)
764 {
765     struct decoder_process_data_st *data = arg;
766     OSSL_DECODER_CTX *ctx = data->ctx;
767     OSSL_DECODER_INSTANCE *decoder_inst = NULL;
768     OSSL_DECODER *decoder = NULL;
769     OSSL_CORE_BIO *cbio = NULL;
770     BIO *bio = data->bio;
771     long loc;
772     size_t i;
773     int ok = 0;
774     /* For recursions */
775     struct decoder_process_data_st new_data;
776     const char *data_type = NULL;
777     const char *data_structure = NULL;
778     /* Saved to restore on return, mutated in PEM->DER transition. */
779     const char *start_input_type = ctx->start_input_type;
780 
781     /*
782      * This is an indicator up the call stack that something was indeed
783      * decoded, leading to a recursive call of this function.
784      */
785     data->flag_next_level_called = 1;
786 
787     memset(&new_data, 0, sizeof(new_data));
788     new_data.ctx = data->ctx;
789     new_data.recursion = data->recursion + 1;
790 
791 #define LEVEL_STR ">>>>>>>>>>>>>>>>"
792 #define LEVEL (new_data.recursion < sizeof(LEVEL_STR)                   \
793                ? &LEVEL_STR[sizeof(LEVEL_STR) - new_data.recursion - 1] \
794                : LEVEL_STR "...")
795 
796     if (params == NULL) {
797         /* First iteration, where we prepare for what is to come */
798 
799         OSSL_TRACE_BEGIN(DECODER) {
800             BIO_printf(trc_out,
801                        "(ctx %p) starting to walk the decoder chain\n",
802                        (void *)new_data.ctx);
803         } OSSL_TRACE_END(DECODER);
804 
805         data->current_decoder_inst_index =
806             OSSL_DECODER_CTX_get_num_decoders(ctx);
807 
808         bio = data->bio;
809     } else {
810         const OSSL_PARAM *p;
811         const char *trace_data_structure;
812 
813         decoder_inst =
814             sk_OSSL_DECODER_INSTANCE_value(ctx->decoder_insts,
815                                            data->current_decoder_inst_index);
816         decoder = OSSL_DECODER_INSTANCE_get_decoder(decoder_inst);
817 
818         data->flag_construct_called = 0;
819         if (ctx->construct != NULL) {
820             int rv;
821 
822             OSSL_TRACE_BEGIN(DECODER) {
823                 BIO_printf(trc_out,
824                            "(ctx %p) %s Running constructor\n",
825                            (void *)new_data.ctx, LEVEL);
826             } OSSL_TRACE_END(DECODER);
827 
828             rv = ctx->construct(decoder_inst, params, ctx->construct_data);
829 
830             OSSL_TRACE_BEGIN(DECODER) {
831                 BIO_printf(trc_out,
832                            "(ctx %p) %s Running constructor => %d\n",
833                            (void *)new_data.ctx, LEVEL, rv);
834             } OSSL_TRACE_END(DECODER);
835 
836             ok = (rv > 0);
837             if (ok) {
838                 data->flag_construct_called = 1;
839                 goto end;
840             }
841         }
842 
843         /* The constructor didn't return success */
844 
845         /*
846          * so we try to use the object we got and feed it to any next
847          * decoder that will take it.  Object references are not
848          * allowed for this.
849          * If this data isn't present, decoding has failed.
850          */
851 
852         p = OSSL_PARAM_locate_const(params, OSSL_OBJECT_PARAM_DATA);
853         if (p == NULL || p->data_type != OSSL_PARAM_OCTET_STRING)
854             goto end;
855         new_data.bio = BIO_new_mem_buf(p->data, (int)p->data_size);
856         if (new_data.bio == NULL)
857             goto end;
858         bio = new_data.bio;
859 
860         /* Get the data type if there is one */
861         p = OSSL_PARAM_locate_const(params, OSSL_OBJECT_PARAM_DATA_TYPE);
862         if (p != NULL && !OSSL_PARAM_get_utf8_string_ptr(p, &data_type))
863             goto end;
864 
865         /* Get the data structure if there is one */
866         p = OSSL_PARAM_locate_const(params, OSSL_OBJECT_PARAM_DATA_STRUCTURE);
867         if (p != NULL && !OSSL_PARAM_get_utf8_string_ptr(p, &data_structure))
868             goto end;
869 
870         /* Get the new input type if there is one */
871         p = OSSL_PARAM_locate_const(params, OSSL_OBJECT_PARAM_INPUT_TYPE);
872         if (p != NULL) {
873             if (!OSSL_PARAM_get_utf8_string_ptr(p, &ctx->start_input_type))
874                 goto end;
875             /*
876              * When switching PKCS8 from PEM to DER we decrypt the data if needed
877              * and then determine the algorithm OID.  Likewise, with SPKI, only
878              * this time sans decryption.
879              */
880             if (ctx->input_structure != NULL
881                 && (OPENSSL_strcasecmp(ctx->input_structure, "SubjectPublicKeyInfo") == 0
882                     || OPENSSL_strcasecmp(data_structure, "PrivateKeyInfo") == 0
883                     || OPENSSL_strcasecmp(ctx->input_structure, "PrivateKeyInfo") == 0))
884                 data->flag_input_structure_checked = 1;
885         }
886 
887         /*
888          * If the data structure is "type-specific" and the data type is
889          * given, we drop the data structure.  The reasoning is that the
890          * data type is already enough to find the applicable next decoder,
891          * so an additional "type-specific" data structure is extraneous.
892          *
893          * Furthermore, if the OSSL_DECODER caller asked for a type specific
894          * structure under another name, such as "DH", we get a mismatch
895          * if the data structure we just received is "type-specific".
896          * There's only so much you can do without infusing this code with
897          * too special knowledge.
898          */
899         trace_data_structure = data_structure;
900         if (data_type != NULL && data_structure != NULL
901             && OPENSSL_strcasecmp(data_structure, "type-specific") == 0)
902             data_structure = NULL;
903 
904         OSSL_TRACE_BEGIN(DECODER) {
905             BIO_printf(trc_out,
906                        "(ctx %p) %s incoming from previous decoder (%p):\n"
907                        "    data type: %s, data structure: %s%s\n",
908                        (void *)new_data.ctx, LEVEL, (void *)decoder,
909                        data_type, trace_data_structure,
910                        (trace_data_structure == data_structure
911                         ? "" : " (dropped)"));
912         } OSSL_TRACE_END(DECODER);
913     }
914 
915     /*
916      * If we have no more decoders to look through at this point,
917      * we failed
918      */
919     if (data->current_decoder_inst_index == 0)
920         goto end;
921 
922     if ((loc = BIO_tell(bio)) < 0) {
923         ERR_raise(ERR_LIB_OSSL_DECODER, ERR_R_BIO_LIB);
924         goto end;
925     }
926 
927     if ((cbio = ossl_core_bio_new_from_bio(bio)) == NULL) {
928         ERR_raise(ERR_LIB_OSSL_DECODER, ERR_R_BIO_LIB);
929         goto end;
930     }
931 
932     for (i = data->current_decoder_inst_index; i-- > 0;) {
933         OSSL_DECODER_INSTANCE *new_decoder_inst =
934             sk_OSSL_DECODER_INSTANCE_value(ctx->decoder_insts, i);
935         OSSL_DECODER *new_decoder =
936             OSSL_DECODER_INSTANCE_get_decoder(new_decoder_inst);
937         const char *new_decoder_name = NULL;
938         void *new_decoderctx =
939             OSSL_DECODER_INSTANCE_get_decoder_ctx(new_decoder_inst);
940         const char *new_input_type =
941             OSSL_DECODER_INSTANCE_get_input_type(new_decoder_inst);
942         int n_i_s_was_set = 0;   /* We don't care here */
943         const char *new_input_structure =
944             OSSL_DECODER_INSTANCE_get_input_structure(new_decoder_inst,
945                                                       &n_i_s_was_set);
946 
947         OSSL_TRACE_BEGIN(DECODER) {
948             new_decoder_name = OSSL_DECODER_get0_name(new_decoder);
949             BIO_printf(trc_out,
950                        "(ctx %p) %s [%u] Considering decoder instance %p (decoder %p):\n"
951                        "    %s with %s\n",
952                        (void *)new_data.ctx, LEVEL, (unsigned int)i,
953                        (void *)new_decoder_inst, (void *)new_decoder,
954                        new_decoder_name,
955                        OSSL_DECODER_get0_properties(new_decoder));
956         } OSSL_TRACE_END(DECODER);
957 
958         /*
959          * If |decoder| is NULL, it means we've just started, and the caller
960          * may have specified what it expects the initial input to be.  If
961          * that's the case, we do this extra check.
962          */
963         if (decoder == NULL && ctx->start_input_type != NULL
964             && OPENSSL_strcasecmp(ctx->start_input_type, new_input_type) != 0) {
965             OSSL_TRACE_BEGIN(DECODER) {
966                 BIO_printf(trc_out,
967                            "(ctx %p) %s [%u] the start input type '%s' doesn't match the input type of the considered decoder, skipping...\n",
968                            (void *)new_data.ctx, LEVEL, (unsigned int)i,
969                            ctx->start_input_type);
970             } OSSL_TRACE_END(DECODER);
971             continue;
972         }
973 
974         /*
975          * If we have a previous decoder, we check that the input type
976          * of the next to be used matches the type of this previous one.
977          * |new_input_type| holds the value of the "input-type" parameter
978          * for the decoder we're currently considering.
979          */
980         if (decoder != NULL && !ossl_decoder_fast_is_a(decoder, new_input_type,
981                                                        &new_decoder_inst->input_type_id)) {
982             OSSL_TRACE_BEGIN(DECODER) {
983                 BIO_printf(trc_out,
984                            "(ctx %p) %s [%u] the input type doesn't match the name of the previous decoder (%p), skipping...\n",
985                            (void *)new_data.ctx, LEVEL, (unsigned int)i,
986                            (void *)decoder);
987             } OSSL_TRACE_END(DECODER);
988             continue;
989         }
990 
991         /*
992          * If the previous decoder gave us a data type, we check to see
993          * if that matches the decoder we're currently considering.
994          */
995         if (data_type != NULL && !OSSL_DECODER_is_a(new_decoder, data_type)) {
996             OSSL_TRACE_BEGIN(DECODER) {
997                 BIO_printf(trc_out,
998                            "(ctx %p) %s [%u] the previous decoder's data type doesn't match the name of the considered decoder, skipping...\n",
999                            (void *)new_data.ctx, LEVEL, (unsigned int)i);
1000             } OSSL_TRACE_END(DECODER);
1001             continue;
1002         }
1003 
1004         /*
1005          * If the previous decoder gave us a data structure name, we check
1006          * to see that it matches the input data structure of the decoder
1007          * we're currently considering.
1008          */
1009         if (data_structure != NULL
1010             && (new_input_structure == NULL
1011                 || OPENSSL_strcasecmp(data_structure,
1012                                       new_input_structure) != 0)) {
1013             OSSL_TRACE_BEGIN(DECODER) {
1014                 BIO_printf(trc_out,
1015                            "(ctx %p) %s [%u] the previous decoder's data structure doesn't match the input structure of the considered decoder, skipping...\n",
1016                            (void *)new_data.ctx, LEVEL, (unsigned int)i);
1017             } OSSL_TRACE_END(DECODER);
1018             continue;
1019         }
1020 
1021         /*
1022          * If the decoder we're currently considering specifies a structure,
1023          * and this check hasn't already been done earlier in this chain of
1024          * decoder_process() calls, check that it matches the user provided
1025          * input structure, if one is given.
1026          */
1027         if (!data->flag_input_structure_checked
1028             && ctx->input_structure != NULL
1029             && new_input_structure != NULL) {
1030             data->flag_input_structure_checked = 1;
1031             if (OPENSSL_strcasecmp(new_input_structure,
1032                                    ctx->input_structure) != 0) {
1033                 OSSL_TRACE_BEGIN(DECODER) {
1034                     BIO_printf(trc_out,
1035                                "(ctx %p) %s [%u] the previous decoder's data structure doesn't match the input structure given by the user, skipping...\n",
1036                                (void *)new_data.ctx, LEVEL, (unsigned int)i);
1037                 } OSSL_TRACE_END(DECODER);
1038                 continue;
1039             }
1040         }
1041 
1042         /*
1043          * Checking the return value of BIO_reset() or BIO_seek() is unsafe.
1044          * Furthermore, BIO_reset() is unsafe to use if the source BIO happens
1045          * to be a BIO_s_mem(), because the earlier BIO_tell() gives us zero
1046          * no matter where we are in the underlying buffer we're reading from.
1047          *
1048          * So, we simply do a BIO_seek(), and use BIO_tell() that we're back
1049          * at the same position.  This is a best effort attempt, but BIO_seek()
1050          * and BIO_tell() should come as a pair...
1051          */
1052         (void)BIO_seek(bio, loc);
1053         if (BIO_tell(bio) != loc)
1054             goto end;
1055 
1056         /* Recurse */
1057         OSSL_TRACE_BEGIN(DECODER) {
1058             BIO_printf(trc_out,
1059                        "(ctx %p) %s [%u] Running decoder instance %s (%p)\n",
1060                        (void *)new_data.ctx, LEVEL, (unsigned int)i,
1061                        new_decoder_name, (void *)new_decoder_inst);
1062         } OSSL_TRACE_END(DECODER);
1063 
1064         /*
1065          * We only care about errors reported from decoder implementations
1066          * if it returns false (i.e. there was a fatal error).
1067          */
1068         ERR_set_mark();
1069 
1070         new_data.current_decoder_inst_index = i;
1071         new_data.flag_input_structure_checked
1072             = data->flag_input_structure_checked;
1073         ok = new_decoder->decode(new_decoderctx, cbio,
1074                                  new_data.ctx->selection,
1075                                  decoder_process, &new_data,
1076                                  ossl_pw_passphrase_callback_dec,
1077                                  &new_data.ctx->pwdata);
1078 
1079         OSSL_TRACE_BEGIN(DECODER) {
1080             BIO_printf(trc_out,
1081                        "(ctx %p) %s [%u] Running decoder instance %s (%p) => %d"
1082                        " (recursed further: %s, construct called: %s)\n",
1083                        (void *)new_data.ctx, LEVEL, (unsigned int)i,
1084                        new_decoder_name, (void *)new_decoder_inst, ok,
1085                        new_data.flag_next_level_called ? "yes" : "no",
1086                        new_data.flag_construct_called ? "yes" : "no");
1087         } OSSL_TRACE_END(DECODER);
1088 
1089         data->flag_construct_called = new_data.flag_construct_called;
1090 
1091         /* Break on error or if we tried to construct an object already */
1092         if (!ok || data->flag_construct_called) {
1093             ERR_clear_last_mark();
1094             break;
1095         }
1096         ERR_pop_to_mark();
1097 
1098         /*
1099          * Break if the decoder implementation that we called recursed, since
1100          * that indicates that it successfully decoded something.
1101          */
1102         if (new_data.flag_next_level_called)
1103             break;
1104     }
1105 
1106  end:
1107     ossl_core_bio_free(cbio);
1108     BIO_free(new_data.bio);
1109     ctx->start_input_type = start_input_type;
1110     return ok;
1111 }
1112