crypto/encode_decode/decoder_lib.c

   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/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
  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
 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
 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
 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
 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
 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
 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(OSSL_DECODER *decoder,
 214                                                  void *decoderctx)
 215 {
 216     OSSL_DECODER_INSTANCE *decoder_inst = NULL;
 217     const OSSL_PROVIDER *prov;
 218     OSSL_LIB_CTX *libctx;
 219     const OSSL_PROPERTY_LIST *props;
 220     const OSSL_PROPERTY_DEFINITION *prop;
 221
 222     if (!ossl_assert(decoder != NULL)) {
 223         ERR_raise(ERR_LIB_OSSL_DECODER, ERR_R_PASSED_NULL_PARAMETER);
 224         return 0;
 225     }
 226
 227     if ((decoder_inst = OPENSSL_zalloc(sizeof(*decoder_inst))) == NULL) {
 228         ERR_raise(ERR_LIB_OSSL_DECODER, ERR_R_MALLOC_FAILURE);
 229         return 0;
 230     }
 231     if (!OSSL_DECODER_up_ref(decoder)) {
 232         ERR_raise(ERR_LIB_OSSL_DECODER, ERR_R_INTERNAL_ERROR);
 233         goto err;
 234     }
 235
 236     prov = OSSL_DECODER_get0_provider(decoder);
 237     libctx = ossl_provider_libctx(prov);
 238     props = ossl_decoder_parsed_properties(decoder);
 239     if (props == NULL) {
 240         ERR_raise_data(ERR_LIB_OSSL_DECODER, ERR_R_INVALID_PROPERTY_DEFINITION,
 241                        "there are no property definitions with decoder %s",
 242                        OSSL_DECODER_get0_name(decoder));
 243         goto err;
 244     }
 245
 246     /* The "input" property is mandatory */
 247     prop = ossl_property_find_property(props, libctx, "input");
 248     decoder_inst->input_type = ossl_property_get_string_value(libctx, prop);
 249     decoder_inst->input_type_id = 0;
 250     if (decoder_inst->input_type == NULL) {
 251         ERR_raise_data(ERR_LIB_OSSL_DECODER, ERR_R_INVALID_PROPERTY_DEFINITION,
 252                        "the mandatory 'input' property is missing "
 253                        "for decoder %s (properties: %s)",
 254                        OSSL_DECODER_get0_name(decoder),
 255                        OSSL_DECODER_get0_properties(decoder));
 256         goto err;
 257     }
 258
 259     /* The "structure" property is optional */
 260     prop = ossl_property_find_property(props, libctx, "structure");
 261     if (prop != NULL) {
 262         decoder_inst->input_structure
 263             = ossl_property_get_string_value(libctx, prop);
 264     }
 265
 266     decoder_inst->decoder = decoder;
 267     decoder_inst->decoderctx = decoderctx;
 268     return decoder_inst;
 269  err:
 270     ossl_decoder_instance_free(decoder_inst);
 271     return NULL;
 272 }
 273
 274 void ossl_decoder_instance_free(OSSL_DECODER_INSTANCE *decoder_inst)
 275 {
 276     if (decoder_inst != NULL) {
 277         if (decoder_inst->decoder != NULL)
 278             decoder_inst->decoder->freectx(decoder_inst->decoderctx);
 279         decoder_inst->decoderctx = NULL;
 280         OSSL_DECODER_free(decoder_inst->decoder);
 281         decoder_inst->decoder = NULL;
 282         OPENSSL_free(decoder_inst);
 283     }
 284 }
 285
 286 int ossl_decoder_ctx_add_decoder_inst(OSSL_DECODER_CTX *ctx,
 287                                       OSSL_DECODER_INSTANCE *di)
 288 {
 289     int ok;
 290
 291     if (ctx->decoder_insts == NULL
 292         && (ctx->decoder_insts =
 293             sk_OSSL_DECODER_INSTANCE_new_null()) == NULL) {
 294         ERR_raise(ERR_LIB_OSSL_DECODER, ERR_R_MALLOC_FAILURE);
 295         return 0;
 296     }
 297
 298     ok = (sk_OSSL_DECODER_INSTANCE_push(ctx->decoder_insts, di) > 0);
 299     if (ok) {
 300         OSSL_TRACE_BEGIN(DECODER) {
 301             BIO_printf(trc_out,
 302                        "(ctx %p) Added decoder instance %p for decoder %p\n"
 303                        "    %s with %s\n",
 304                        (void *)ctx, (void *)di, (void *)di->decoder,
 305                        OSSL_DECODER_get0_name(di->decoder),
 306                        OSSL_DECODER_get0_properties(di->decoder));
 307         } OSSL_TRACE_END(DECODER);
 308     }
 309     return ok;
 310 }
 311
 312 int OSSL_DECODER_CTX_add_decoder(OSSL_DECODER_CTX *ctx, OSSL_DECODER *decoder)
 313 {
 314     OSSL_DECODER_INSTANCE *decoder_inst = NULL;
 315     const OSSL_PROVIDER *prov = NULL;
 316     void *decoderctx = NULL;
 317     void *provctx = NULL;
 318
 319     if (!ossl_assert(ctx != NULL) || !ossl_assert(decoder != NULL)) {
 320         ERR_raise(ERR_LIB_OSSL_DECODER, ERR_R_PASSED_NULL_PARAMETER);
 321         return 0;
 322     }
 323
 324     prov = OSSL_DECODER_get0_provider(decoder);
 325     provctx = OSSL_PROVIDER_get0_provider_ctx(prov);
 326
 327     if ((decoderctx = decoder->newctx(provctx)) == NULL
 328         || (decoder_inst =
 329             ossl_decoder_instance_new(decoder, decoderctx)) == NULL)
 330         goto err;
 331     /* Avoid double free of decoderctx on further errors */
 332     decoderctx = NULL;
 333
 334     if (!ossl_decoder_ctx_add_decoder_inst(ctx, decoder_inst))
 335         goto err;
 336
 337     return 1;
 338  err:
 339     ossl_decoder_instance_free(decoder_inst);
 340     if (decoderctx != NULL)
 341         decoder->freectx(decoderctx);
 342     return 0;
 343 }
 344
 345 struct collect_extra_decoder_data_st {
 346     OSSL_DECODER_CTX *ctx;
 347     const char *output_type;
 348     int output_type_id;
 349
 350     /*
 351      * 0 to check that the decoder's input type is the same as the decoder name
 352      * 1 to check that the decoder's input type differs from the decoder name
 353      */
 354     enum { IS_SAME = 0, IS_DIFFERENT = 1 } type_check;
 355     size_t w_prev_start, w_prev_end; /* "previous" decoders */
 356     size_t w_new_start, w_new_end;   /* "new" decoders */
 357 };
 358
 359 DEFINE_STACK_OF(OSSL_DECODER)
 360
 361 static void collect_all_decoders(OSSL_DECODER *decoder, void *arg)
 362 {
 363     STACK_OF(OSSL_DECODER) *skdecoders = arg;
 364
 365     if (OSSL_DECODER_up_ref(decoder))
 366         sk_OSSL_DECODER_push(skdecoders, decoder);
 367 }
 368
 369 static void collect_extra_decoder(OSSL_DECODER *decoder, void *arg)
 370 {
 371     struct collect_extra_decoder_data_st *data = arg;
 372     size_t j;
 373     const OSSL_PROVIDER *prov = OSSL_DECODER_get0_provider(decoder);
 374     void *provctx = OSSL_PROVIDER_get0_provider_ctx(prov);
 375
 376     if (ossl_decoder_fast_is_a(decoder, data->output_type, &data->output_type_id)) {
 377         void *decoderctx = NULL;
 378         OSSL_DECODER_INSTANCE *di = NULL;
 379
 380         OSSL_TRACE_BEGIN(DECODER) {
 381             BIO_printf(trc_out,
 382                        "(ctx %p) [%d] Checking out decoder %p:\n"
 383                        "    %s with %s\n",
 384                        (void *)data->ctx, data->type_check, (void *)decoder,
 385                        OSSL_DECODER_get0_name(decoder),
 386                        OSSL_DECODER_get0_properties(decoder));
 387         } OSSL_TRACE_END(DECODER);
 388
 389         /*
 390          * Check that we don't already have this decoder in our stack,
 391          * starting with the previous windows but also looking at what
 392          * we have added in the current window.
 393          */
 394         for (j = data->w_prev_start; j < data->w_new_end; j++) {
 395             OSSL_DECODER_INSTANCE *check_inst =
 396                 sk_OSSL_DECODER_INSTANCE_value(data->ctx->decoder_insts, j);
 397
 398             if (decoder->base.algodef == check_inst->decoder->base.algodef) {
 399                 /* We found it, so don't do anything more */
 400                 OSSL_TRACE_BEGIN(DECODER) {
 401                     BIO_printf(trc_out,
 402                                "    REJECTED: already exists in the chain\n");
 403                 } OSSL_TRACE_END(DECODER);
 404                 return;
 405             }
 406         }
 407
 408         if ((decoderctx = decoder->newctx(provctx)) == NULL)
 409             return;
 410
 411         if ((di = ossl_decoder_instance_new(decoder, decoderctx)) == NULL) {
 412             decoder->freectx(decoderctx);
 413             return;
 414         }
 415
 416         switch (data->type_check) {
 417         case IS_SAME:
 418             /* If it differs, this is not a decoder to add for now. */
 419             if (!ossl_decoder_fast_is_a(decoder,
 420                                         OSSL_DECODER_INSTANCE_get_input_type(di),
 421                                         &di->input_type_id)) {
 422                 ossl_decoder_instance_free(di);
 423                 OSSL_TRACE_BEGIN(DECODER) {
 424                     BIO_printf(trc_out,
 425                                "    REJECTED: input type doesn't match output type\n");
 426                 } OSSL_TRACE_END(DECODER);
 427                 return;
 428             }
 429             break;
 430         case IS_DIFFERENT:
 431             /* If it's the same, this is not a decoder to add for now. */
 432             if (ossl_decoder_fast_is_a(decoder,
 433                                        OSSL_DECODER_INSTANCE_get_input_type(di),
 434                                        &di->input_type_id)) {
 435                 ossl_decoder_instance_free(di);
 436                 OSSL_TRACE_BEGIN(DECODER) {
 437                     BIO_printf(trc_out,
 438                                "    REJECTED: input type matches output type\n");
 439                 } OSSL_TRACE_END(DECODER);
 440                 return;
 441             }
 442             break;
 443         }
 444
 445         /*
 446          * Apart from keeping w_new_end up to date, We don't care about
 447          * errors here.  If it doesn't collect, then it doesn't...
 448          */
 449         if (!ossl_decoder_ctx_add_decoder_inst(data->ctx, di)) {
 450             ossl_decoder_instance_free(di);
 451             return;
 452         }
 453
 454         data->w_new_end++;
 455     }
 456 }
 457
 458 int OSSL_DECODER_CTX_add_extra(OSSL_DECODER_CTX *ctx,
 459                                OSSL_LIB_CTX *libctx, const char *propq)
 460 {
 461     /*
 462      * This function goes through existing decoder methods in
 463      * |ctx->decoder_insts|, and tries to fetch new decoders that produce
 464      * what the existing ones want as input, and push those newly fetched
 465      * decoders on top of the same stack.
 466      * Then it does the same again, but looping over the newly fetched
 467      * decoders, until there are no more decoders to be fetched, or
 468      * when we have done this 10 times.
 469      *
 470      * we do this with sliding windows on the stack by keeping track of indexes
 471      * and of the end.
 472      *
 473      * +----------------+
 474      * |   DER to RSA   | <--- w_prev_start
 475      * +----------------+
 476      * |   DER to DSA   |
 477      * +----------------+
 478      * |   DER to DH    |
 479      * +----------------+
 480      * |   PEM to DER   | <--- w_prev_end, w_new_start
 481      * +----------------+
 482      *                    <--- w_new_end
 483      */
 484     struct collect_extra_decoder_data_st data;
 485     size_t depth = 0; /* Counts the number of iterations */
 486     size_t count; /* Calculates how many were added in each iteration */
 487     size_t numdecoders;
 488     STACK_OF(OSSL_DECODER) *skdecoders;
 489
 490     if (!ossl_assert(ctx != NULL)) {
 491         ERR_raise(ERR_LIB_OSSL_DECODER, ERR_R_PASSED_NULL_PARAMETER);
 492         return 0;
 493     }
 494
 495     /*
 496      * If there is no stack of OSSL_DECODER_INSTANCE, we have nothing
 497      * more to add.  That's fine.
 498      */
 499     if (ctx->decoder_insts == NULL)
 500         return 1;
 501
 502     OSSL_TRACE_BEGIN(DECODER) {
 503         BIO_printf(trc_out, "(ctx %p) Looking for extra decoders\n",
 504                    (void *)ctx);
 505     } OSSL_TRACE_END(DECODER);
 506
 507
 508     skdecoders = sk_OSSL_DECODER_new_null();
 509     if (skdecoders == NULL) {
 510         ERR_raise(ERR_LIB_OSSL_DECODER, ERR_R_MALLOC_FAILURE);
 511         return 0;
 512     }
 513     OSSL_DECODER_do_all_provided(libctx, collect_all_decoders, skdecoders);
 514     numdecoders = sk_OSSL_DECODER_num(skdecoders);
 515
 516     memset(&data, 0, sizeof(data));
 517     data.ctx = ctx;
 518     data.w_prev_start = 0;
 519     data.w_prev_end = sk_OSSL_DECODER_INSTANCE_num(ctx->decoder_insts);
 520     do {
 521         size_t i, j;
 522
 523         data.w_new_start = data.w_new_end = data.w_prev_end;
 524
 525         /*
 526          * Two iterations:
 527          * 0.  All decoders that have the same name as their input type.
 528          *     This allows for decoders that unwrap some data in a specific
 529          *     encoding, and pass the result on with the same encoding.
 530          * 1.  All decoders that a different name than their input type.
 531          */
 532         for (data.type_check = IS_SAME;
 533              data.type_check <= IS_DIFFERENT;
 534              data.type_check++) {
 535             for (i = data.w_prev_start; i < data.w_prev_end; i++) {
 536                 OSSL_DECODER_INSTANCE *decoder_inst =
 537                     sk_OSSL_DECODER_INSTANCE_value(ctx->decoder_insts, i);
 538
 539                 data.output_type
 540                     = OSSL_DECODER_INSTANCE_get_input_type(decoder_inst);
 541
 542                 data.output_type_id = 0;
 543
 544                 for (j = 0; j < numdecoders; j++)
 545                     collect_extra_decoder(sk_OSSL_DECODER_value(skdecoders, j),
 546                                           &data);
 547             }
 548         }
 549         /* How many were added in this iteration */
 550         count = data.w_new_end - data.w_new_start;
 551
 552         /* Slide the "previous decoder" windows */
 553         data.w_prev_start = data.w_new_start;
 554         data.w_prev_end = data.w_new_end;
 555
 556         depth++;
 557     } while (count != 0 && depth <= 10);
 558
 559     sk_OSSL_DECODER_pop_free(skdecoders, OSSL_DECODER_free);
 560     return 1;
 561 }
 562
 563 int OSSL_DECODER_CTX_get_num_decoders(OSSL_DECODER_CTX *ctx)
 564 {
 565     if (ctx == NULL || ctx->decoder_insts == NULL)
 566         return 0;
 567     return sk_OSSL_DECODER_INSTANCE_num(ctx->decoder_insts);
 568 }
 569
 570 int OSSL_DECODER_CTX_set_construct(OSSL_DECODER_CTX *ctx,
 571                                    OSSL_DECODER_CONSTRUCT *construct)
 572 {
 573     if (!ossl_assert(ctx != NULL)) {
 574         ERR_raise(ERR_LIB_OSSL_DECODER, ERR_R_PASSED_NULL_PARAMETER);
 575         return 0;
 576     }
 577     ctx->construct = construct;
 578     return 1;
 579 }
 580
 581 int OSSL_DECODER_CTX_set_construct_data(OSSL_DECODER_CTX *ctx,
 582                                         void *construct_data)
 583 {
 584     if (!ossl_assert(ctx != NULL)) {
 585         ERR_raise(ERR_LIB_OSSL_DECODER, ERR_R_PASSED_NULL_PARAMETER);
 586         return 0;
 587     }
 588     ctx->construct_data = construct_data;
 589     return 1;
 590 }
 591
 592 int OSSL_DECODER_CTX_set_cleanup(OSSL_DECODER_CTX *ctx,
 593                                  OSSL_DECODER_CLEANUP *cleanup)
 594 {
 595     if (!ossl_assert(ctx != NULL)) {
 596         ERR_raise(ERR_LIB_OSSL_DECODER, ERR_R_PASSED_NULL_PARAMETER);
 597         return 0;
 598     }
 599     ctx->cleanup = cleanup;
 600     return 1;
 601 }
 602
 603 OSSL_DECODER_CONSTRUCT *
 604 OSSL_DECODER_CTX_get_construct(OSSL_DECODER_CTX *ctx)
 605 {
 606     if (ctx == NULL)
 607         return NULL;
 608     return ctx->construct;
 609 }
 610
 611 void *OSSL_DECODER_CTX_get_construct_data(OSSL_DECODER_CTX *ctx)
 612 {
 613     if (ctx == NULL)
 614         return NULL;
 615     return ctx->construct_data;
 616 }
 617
 618 OSSL_DECODER_CLEANUP *
 619 OSSL_DECODER_CTX_get_cleanup(OSSL_DECODER_CTX *ctx)
 620 {
 621     if (ctx == NULL)
 622         return NULL;
 623     return ctx->cleanup;
 624 }
 625
 626 int OSSL_DECODER_export(OSSL_DECODER_INSTANCE *decoder_inst,
 627                         void *reference, size_t reference_sz,
 628                         OSSL_CALLBACK *export_cb, void *export_cbarg)
 629 {
 630     OSSL_DECODER *decoder = NULL;
 631     void *decoderctx = NULL;
 632
 633     if (!(ossl_assert(decoder_inst != NULL)
 634           && ossl_assert(reference != NULL)
 635           && ossl_assert(export_cb != NULL)
 636           && ossl_assert(export_cbarg != NULL))) {
 637         ERR_raise(ERR_LIB_OSSL_DECODER, ERR_R_PASSED_NULL_PARAMETER);
 638         return 0;
 639     }
 640
 641     decoder = OSSL_DECODER_INSTANCE_get_decoder(decoder_inst);
 642     decoderctx = OSSL_DECODER_INSTANCE_get_decoder_ctx(decoder_inst);
 643     return decoder->export_object(decoderctx, reference, reference_sz,
 644                                   export_cb, export_cbarg);
 645 }
 646
 647 OSSL_DECODER *
 648 OSSL_DECODER_INSTANCE_get_decoder(OSSL_DECODER_INSTANCE *decoder_inst)
 649 {
 650     if (decoder_inst == NULL)
 651         return NULL;
 652     return decoder_inst->decoder;
 653 }
 654
 655 void *
 656 OSSL_DECODER_INSTANCE_get_decoder_ctx(OSSL_DECODER_INSTANCE *decoder_inst)
 657 {
 658     if (decoder_inst == NULL)
 659         return NULL;
 660     return decoder_inst->decoderctx;
 661 }
 662
 663 const char *
 664 OSSL_DECODER_INSTANCE_get_input_type(OSSL_DECODER_INSTANCE *decoder_inst)
 665 {
 666     if (decoder_inst == NULL)
 667         return NULL;
 668     return decoder_inst->input_type;
 669 }
 670
 671 const char *
 672 OSSL_DECODER_INSTANCE_get_input_structure(OSSL_DECODER_INSTANCE *decoder_inst,
 673                                           int *was_set)
 674 {
 675     if (decoder_inst == NULL)
 676         return NULL;
 677     *was_set = decoder_inst->flag_input_structure_was_set;
 678     return decoder_inst->input_structure;
 679 }
 680
 681 static int decoder_process(const OSSL_PARAM params[], void *arg)
 682 {
 683     struct decoder_process_data_st *data = arg;
 684     OSSL_DECODER_CTX *ctx = data->ctx;
 685     OSSL_DECODER_INSTANCE *decoder_inst = NULL;
 686     OSSL_DECODER *decoder = NULL;
 687     OSSL_CORE_BIO *cbio = NULL;
 688     BIO *bio = data->bio;
 689     long loc;
 690     size_t i;
 691     int ok = 0;
 692     /* For recursions */
 693     struct decoder_process_data_st new_data;
 694     const char *data_type = NULL;
 695     const char *data_structure = NULL;
 696
 697     /*
 698      * This is an indicator up the call stack that something was indeed
 699      * decoded, leading to a recursive call of this function.
 700      */
 701     data->flag_next_level_called = 1;
 702
 703     memset(&new_data, 0, sizeof(new_data));
 704     new_data.ctx = data->ctx;
 705     new_data.recursion = data->recursion + 1;
 706
 707 #define LEVEL_STR ">>>>>>>>>>>>>>>>"
 708 #define LEVEL (new_data.recursion < sizeof(LEVEL_STR)                   \
 709                ? &LEVEL_STR[sizeof(LEVEL_STR) - new_data.recursion - 1] \
 710                : LEVEL_STR "...")
 711
 712     if (params == NULL) {
 713         /* First iteration, where we prepare for what is to come */
 714
 715         OSSL_TRACE_BEGIN(DECODER) {
 716             BIO_printf(trc_out,
 717                        "(ctx %p) starting to walk the decoder chain\n",
 718                        (void *)new_data.ctx);
 719         } OSSL_TRACE_END(DECODER);
 720
 721         data->current_decoder_inst_index =
 722             OSSL_DECODER_CTX_get_num_decoders(ctx);
 723
 724         bio = data->bio;
 725     } else {
 726         const OSSL_PARAM *p;
 727         const char *trace_data_structure;
 728
 729         decoder_inst =
 730             sk_OSSL_DECODER_INSTANCE_value(ctx->decoder_insts,
 731                                            data->current_decoder_inst_index);
 732         decoder = OSSL_DECODER_INSTANCE_get_decoder(decoder_inst);
 733
 734         data->flag_construct_called = 0;
 735         if (ctx->construct != NULL) {
 736             int rv;
 737
 738             OSSL_TRACE_BEGIN(DECODER) {
 739                 BIO_printf(trc_out,
 740                            "(ctx %p) %s Running constructor\n",
 741                            (void *)new_data.ctx, LEVEL);
 742             } OSSL_TRACE_END(DECODER);
 743
 744             rv = ctx->construct(decoder_inst, params, ctx->construct_data);
 745
 746             OSSL_TRACE_BEGIN(DECODER) {
 747                 BIO_printf(trc_out,
 748                            "(ctx %p) %s Running constructor => %d\n",
 749                            (void *)new_data.ctx, LEVEL, rv);
 750             } OSSL_TRACE_END(DECODER);
 751
 752             data->flag_construct_called = 1;
 753             ok = (rv > 0);
 754             if (ok)
 755                 goto end;
 756         }
 757
 758         /* The constructor didn't return success */
 759
 760         /*
 761          * so we try to use the object we got and feed it to any next
 762          * decoder that will take it.  Object references are not
 763          * allowed for this.
 764          * If this data isn't present, decoding has failed.
 765          */
 766
 767         p = OSSL_PARAM_locate_const(params, OSSL_OBJECT_PARAM_DATA);
 768         if (p == NULL || p->data_type != OSSL_PARAM_OCTET_STRING)
 769             goto end;
 770         new_data.bio = BIO_new_mem_buf(p->data, (int)p->data_size);
 771         if (new_data.bio == NULL)
 772             goto end;
 773         bio = new_data.bio;
 774
 775         /* Get the data type if there is one */
 776         p = OSSL_PARAM_locate_const(params, OSSL_OBJECT_PARAM_DATA_TYPE);
 777         if (p != NULL && !OSSL_PARAM_get_utf8_string_ptr(p, &data_type))
 778             goto end;
 779
 780         /* Get the data structure if there is one */
 781         p = OSSL_PARAM_locate_const(params, OSSL_OBJECT_PARAM_DATA_STRUCTURE);
 782         if (p != NULL && !OSSL_PARAM_get_utf8_string_ptr(p, &data_structure))
 783             goto end;
 784
 785         /*
 786          * If the data structure is "type-specific" and the data type is
 787          * given, we drop the data structure.  The reasoning is that the
 788          * data type is already enough to find the applicable next decoder,
 789          * so an additional "type-specific" data structure is extraneous.
 790          *
 791          * Furthermore, if the OSSL_DECODER caller asked for a type specific
 792          * structure under another name, such as "DH", we get a mismatch
 793          * if the data structure we just received is "type-specific".
 794          * There's only so much you can do without infusing this code with
 795          * too special knowledge.
 796          */
 797         trace_data_structure = data_structure;
 798         if (data_type != NULL && data_structure != NULL
 799             && OPENSSL_strcasecmp(data_structure, "type-specific") == 0)
 800             data_structure = NULL;
 801
 802         OSSL_TRACE_BEGIN(DECODER) {
 803             BIO_printf(trc_out,
 804                        "(ctx %p) %s incoming from previous decoder (%p):\n"
 805                        "    data type: %s, data structure: %s%s\n",
 806                        (void *)new_data.ctx, LEVEL, (void *)decoder,
 807                        data_type, trace_data_structure,
 808                        (trace_data_structure == data_structure
 809                         ? "" : " (dropped)"));
 810         } OSSL_TRACE_END(DECODER);
 811     }
 812
 813     /*
 814      * If we have no more decoders to look through at this point,
 815      * we failed
 816      */
 817     if (data->current_decoder_inst_index == 0)
 818         goto end;
 819
 820     if ((loc = BIO_tell(bio)) < 0) {
 821         ERR_raise(ERR_LIB_OSSL_DECODER, ERR_R_BIO_LIB);
 822         goto end;
 823     }
 824
 825     if ((cbio = ossl_core_bio_new_from_bio(bio)) == NULL) {
 826         ERR_raise(ERR_LIB_OSSL_DECODER, ERR_R_MALLOC_FAILURE);
 827         goto end;
 828     }
 829
 830     for (i = data->current_decoder_inst_index; i-- > 0;) {
 831         OSSL_DECODER_INSTANCE *new_decoder_inst =
 832             sk_OSSL_DECODER_INSTANCE_value(ctx->decoder_insts, i);
 833         OSSL_DECODER *new_decoder =
 834             OSSL_DECODER_INSTANCE_get_decoder(new_decoder_inst);
 835         void *new_decoderctx =
 836             OSSL_DECODER_INSTANCE_get_decoder_ctx(new_decoder_inst);
 837         const char *new_input_type =
 838             OSSL_DECODER_INSTANCE_get_input_type(new_decoder_inst);
 839         int n_i_s_was_set = 0;   /* We don't care here */
 840         const char *new_input_structure =
 841             OSSL_DECODER_INSTANCE_get_input_structure(new_decoder_inst,
 842                                                       &n_i_s_was_set);
 843
 844         OSSL_TRACE_BEGIN(DECODER) {
 845             BIO_printf(trc_out,
 846                        "(ctx %p) %s [%u] Considering decoder instance %p (decoder %p):\n"
 847                        "    %s with %s\n",
 848                        (void *)new_data.ctx, LEVEL, (unsigned int)i,
 849                        (void *)new_decoder_inst, (void *)new_decoder,
 850                        OSSL_DECODER_get0_name(new_decoder),
 851                        OSSL_DECODER_get0_properties(new_decoder));
 852         } OSSL_TRACE_END(DECODER);
 853
 854         /*
 855          * If |decoder| is NULL, it means we've just started, and the caller
 856          * may have specified what it expects the initial input to be.  If
 857          * that's the case, we do this extra check.
 858          */
 859         if (decoder == NULL && ctx->start_input_type != NULL
 860             && OPENSSL_strcasecmp(ctx->start_input_type, new_input_type) != 0) {
 861             OSSL_TRACE_BEGIN(DECODER) {
 862                 BIO_printf(trc_out,
 863                            "(ctx %p) %s [%u] the start input type '%s' doesn't match the input type of the considered decoder, skipping...\n",
 864                            (void *)new_data.ctx, LEVEL, (unsigned int)i,
 865                            ctx->start_input_type);
 866             } OSSL_TRACE_END(DECODER);
 867             continue;
 868         }
 869
 870         /*
 871          * If we have a previous decoder, we check that the input type
 872          * of the next to be used matches the type of this previous one.
 873          * |new_input_type| holds the value of the "input-type" parameter
 874          * for the decoder we're currently considering.
 875          */
 876         if (decoder != NULL && !ossl_decoder_fast_is_a(decoder, new_input_type,
 877                                                        &new_decoder_inst->input_type_id)) {
 878             OSSL_TRACE_BEGIN(DECODER) {
 879                 BIO_printf(trc_out,
 880                            "(ctx %p) %s [%u] the input type doesn't match the name of the previous decoder (%p), skipping...\n",
 881                            (void *)new_data.ctx, LEVEL, (unsigned int)i,
 882                            (void *)decoder);
 883             } OSSL_TRACE_END(DECODER);
 884             continue;
 885         }
 886
 887         /*
 888          * If the previous decoder gave us a data type, we check to see
 889          * if that matches the decoder we're currently considering.
 890          */
 891         if (data_type != NULL && !OSSL_DECODER_is_a(new_decoder, data_type)) {
 892             OSSL_TRACE_BEGIN(DECODER) {
 893                 BIO_printf(trc_out,
 894                            "(ctx %p) %s [%u] the previous decoder's data type doesn't match the name of the considered decoder, skipping...\n",
 895                            (void *)new_data.ctx, LEVEL, (unsigned int)i);
 896             } OSSL_TRACE_END(DECODER);
 897             continue;
 898         }
 899
 900         /*
 901          * If the previous decoder gave us a data structure name, we check
 902          * to see that it matches the input data structure of the decoder
 903          * we're currently considering.
 904          */
 905         if (data_structure != NULL
 906             && (new_input_structure == NULL
 907                 || OPENSSL_strcasecmp(data_structure,
 908                                       new_input_structure) != 0)) {
 909             OSSL_TRACE_BEGIN(DECODER) {
 910                 BIO_printf(trc_out,
 911                            "(ctx %p) %s [%u] the previous decoder's data structure doesn't match the input structure of the considered decoder, skipping...\n",
 912                            (void *)new_data.ctx, LEVEL, (unsigned int)i);
 913             } OSSL_TRACE_END(DECODER);
 914             continue;
 915         }
 916
 917         /*
 918          * If the decoder we're currently considering specifies a structure,
 919          * and this check hasn't already been done earlier in this chain of
 920          * decoder_process() calls, check that it matches the user provided
 921          * input structure, if one is given.
 922          */
 923         if (!data->flag_input_structure_checked
 924             && ctx->input_structure != NULL
 925             && new_input_structure != NULL) {
 926             data->flag_input_structure_checked = 1;
 927             if (OPENSSL_strcasecmp(new_input_structure,
 928                                    ctx->input_structure) != 0) {
 929                 OSSL_TRACE_BEGIN(DECODER) {
 930                     BIO_printf(trc_out,
 931                                "(ctx %p) %s [%u] the previous decoder's data structure doesn't match the input structure given by the user, skipping...\n",
 932                                (void *)new_data.ctx, LEVEL, (unsigned int)i);
 933                 } OSSL_TRACE_END(DECODER);
 934                 continue;
 935             }
 936         }
 937
 938         /*
 939          * Checking the return value of BIO_reset() or BIO_seek() is unsafe.
 940          * Furthermore, BIO_reset() is unsafe to use if the source BIO happens
 941          * to be a BIO_s_mem(), because the earlier BIO_tell() gives us zero
 942          * no matter where we are in the underlying buffer we're reading from.
 943          *
 944          * So, we simply do a BIO_seek(), and use BIO_tell() that we're back
 945          * at the same position.  This is a best effort attempt, but BIO_seek()
 946          * and BIO_tell() should come as a pair...
 947          */
 948         (void)BIO_seek(bio, loc);
 949         if (BIO_tell(bio) != loc)
 950             goto end;
 951
 952         /* Recurse */
 953         OSSL_TRACE_BEGIN(DECODER) {
 954             BIO_printf(trc_out,
 955                        "(ctx %p) %s [%u] Running decoder instance %p\n",
 956                        (void *)new_data.ctx, LEVEL, (unsigned int)i,
 957                        (void *)new_decoder_inst);
 958         } OSSL_TRACE_END(DECODER);
 959
 960         /*
 961          * We only care about errors reported from decoder implementations
 962          * if it returns false (i.e. there was a fatal error).
 963          */
 964         ERR_set_mark();
 965
 966         new_data.current_decoder_inst_index = i;
 967         new_data.flag_input_structure_checked
 968             = data->flag_input_structure_checked;
 969         ok = new_decoder->decode(new_decoderctx, cbio,
 970                                  new_data.ctx->selection,
 971                                  decoder_process, &new_data,
 972                                  ossl_pw_passphrase_callback_dec,
 973                                  &new_data.ctx->pwdata);
 974
 975         OSSL_TRACE_BEGIN(DECODER) {
 976             BIO_printf(trc_out,
 977                        "(ctx %p) %s [%u] Running decoder instance %p => %d"
 978                        " (recursed further: %s, construct called: %s)\n",
 979                        (void *)new_data.ctx, LEVEL, (unsigned int)i,
 980                        (void *)new_decoder_inst, ok,
 981                        new_data.flag_next_level_called ? "yes" : "no",
 982                        new_data.flag_construct_called ? "yes" : "no");
 983         } OSSL_TRACE_END(DECODER);
 984
 985         data->flag_construct_called = new_data.flag_construct_called;
 986
 987         /* Break on error or if we tried to construct an object already */
 988         if (!ok || data->flag_construct_called) {
 989             ERR_clear_last_mark();
 990             break;
 991         }
 992         ERR_pop_to_mark();
 993
 994         /*
 995          * Break if the decoder implementation that we called recursed, since
 996          * that indicates that it successfully decoded something.
 997          */
 998         if (new_data.flag_next_level_called)
 999             break;
1000     }
1001
1002  end:
1003     ossl_core_bio_free(cbio);
1004     BIO_free(new_data.bio);
1005     return ok;
1006 }