crypto/encode_decode/decoder_pkey.c

   1 /*
   2  * Copyright 2020-2021 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 <openssl/core_names.h>
  11 #include <openssl/core_object.h>
  12 #include <openssl/provider.h>
  13 #include <openssl/evp.h>
  14 #include <openssl/ui.h>
  15 #include <openssl/decoder.h>
  16 #include <openssl/safestack.h>
  17 #include <openssl/trace.h>
  18 #include "crypto/evp.h"
  19 #include "crypto/decoder.h"
  20 #include "crypto/evp/evp_local.h"
  21 #include "encoder_local.h"
  22 #include "internal/namemap.h"
  23
  24 int OSSL_DECODER_CTX_set_passphrase(OSSL_DECODER_CTX *ctx,
  25                                     const unsigned char *kstr,
  26                                     size_t klen)
  27 {
  28     return ossl_pw_set_passphrase(&ctx->pwdata, kstr, klen);
  29 }
  30
  31 int OSSL_DECODER_CTX_set_passphrase_ui(OSSL_DECODER_CTX *ctx,
  32                                        const UI_METHOD *ui_method,
  33                                        void *ui_data)
  34 {
  35     return ossl_pw_set_ui_method(&ctx->pwdata, ui_method, ui_data);
  36 }
  37
  38 int OSSL_DECODER_CTX_set_pem_password_cb(OSSL_DECODER_CTX *ctx,
  39                                          pem_password_cb *cb, void *cbarg)
  40 {
  41     return ossl_pw_set_pem_password_cb(&ctx->pwdata, cb, cbarg);
  42 }
  43
  44 int OSSL_DECODER_CTX_set_passphrase_cb(OSSL_DECODER_CTX *ctx,
  45                                        OSSL_PASSPHRASE_CALLBACK *cb,
  46                                        void *cbarg)
  47 {
  48     return ossl_pw_set_ossl_passphrase_cb(&ctx->pwdata, cb, cbarg);
  49 }
  50
  51 /*
  52  * Support for OSSL_DECODER_CTX_new_for_pkey:
  53  * The construct data, and collecting keymgmt information for it
  54  */
  55
  56 DEFINE_STACK_OF(EVP_KEYMGMT)
  57
  58 struct decoder_pkey_data_st {
  59     OSSL_LIB_CTX *libctx;
  60     char *propq;
  61     int selection;
  62
  63     STACK_OF(EVP_KEYMGMT) *keymgmts;
  64     char *object_type;           /* recorded object data type, may be NULL */
  65     void **object;               /* Where the result should end up */
  66 };
  67
  68 static int decoder_construct_pkey(OSSL_DECODER_INSTANCE *decoder_inst,
  69                                   const OSSL_PARAM *params,
  70                                   void *construct_data)
  71 {
  72     struct decoder_pkey_data_st *data = construct_data;
  73     OSSL_DECODER *decoder = OSSL_DECODER_INSTANCE_get_decoder(decoder_inst);
  74     void *decoderctx = OSSL_DECODER_INSTANCE_get_decoder_ctx(decoder_inst);
  75     const OSSL_PROVIDER *decoder_prov = OSSL_DECODER_get0_provider(decoder);
  76     EVP_KEYMGMT *keymgmt = NULL;
  77     const OSSL_PROVIDER *keymgmt_prov = NULL;
  78     int i, end;
  79     /*
  80      * |object_ref| points to a provider reference to an object, its exact
  81      * contents entirely opaque to us, but may be passed to any provider
  82      * function that expects this (such as OSSL_FUNC_keymgmt_load().
  83      *
  84      * This pointer is considered volatile, i.e. whatever it points at
  85      * is assumed to be freed as soon as this function returns.
  86      */
  87     void *object_ref = NULL;
  88     size_t object_ref_sz = 0;
  89     const OSSL_PARAM *p;
  90
  91     p = OSSL_PARAM_locate_const(params, OSSL_OBJECT_PARAM_DATA_TYPE);
  92     if (p != NULL) {
  93         char *object_type = NULL;
  94
  95         if (!OSSL_PARAM_get_utf8_string(p, &object_type, 0))
  96             return 0;
  97         OPENSSL_free(data->object_type);
  98         data->object_type = object_type;
  99     }
 100
 101     /*
 102      * For stuff that should end up in an EVP_PKEY, we only accept an object
 103      * reference for the moment.  This enforces that the key data itself
 104      * remains with the provider.
 105      */
 106     p = OSSL_PARAM_locate_const(params, OSSL_OBJECT_PARAM_REFERENCE);
 107     if (p == NULL || p->data_type != OSSL_PARAM_OCTET_STRING)
 108         return 0;
 109     object_ref = p->data;
 110     object_ref_sz = p->data_size;
 111
 112     /*
 113      * First, we try to find a keymgmt that comes from the same provider as
 114      * the decoder that passed the params.
 115      */
 116     end = sk_EVP_KEYMGMT_num(data->keymgmts);
 117     for (i = 0; i < end; i++) {
 118         keymgmt = sk_EVP_KEYMGMT_value(data->keymgmts, i);
 119         keymgmt_prov = EVP_KEYMGMT_get0_provider(keymgmt);
 120
 121         if (keymgmt_prov == decoder_prov
 122             && evp_keymgmt_has_load(keymgmt)
 123             && EVP_KEYMGMT_is_a(keymgmt, data->object_type))
 124             break;
 125     }
 126     if (i < end) {
 127         /* To allow it to be freed further down */
 128         if (!EVP_KEYMGMT_up_ref(keymgmt))
 129             return 0;
 130     } else if ((keymgmt = EVP_KEYMGMT_fetch(data->libctx,
 131                                             data->object_type,
 132                                             data->propq)) != NULL) {
 133         keymgmt_prov = EVP_KEYMGMT_get0_provider(keymgmt);
 134     }
 135
 136     if (keymgmt != NULL) {
 137         EVP_PKEY *pkey = NULL;
 138         void *keydata = NULL;
 139
 140         /*
 141          * If the EVP_KEYMGMT and the OSSL_DECODER are from the
 142          * same provider, we assume that the KEYMGMT has a key loading
 143          * function that can handle the provider reference we hold.
 144          *
 145          * Otherwise, we export from the decoder and import the
 146          * result in the keymgmt.
 147          */
 148         if (keymgmt_prov == decoder_prov) {
 149             keydata = evp_keymgmt_load(keymgmt, object_ref, object_ref_sz);
 150         } else {
 151             struct evp_keymgmt_util_try_import_data_st import_data;
 152
 153             import_data.keymgmt = keymgmt;
 154             import_data.keydata = NULL;
 155             import_data.selection = data->selection;
 156
 157             /*
 158              * No need to check for errors here, the value of
 159              * |import_data.keydata| is as much an indicator.
 160              */
 161             (void)decoder->export_object(decoderctx,
 162                                          object_ref, object_ref_sz,
 163                                          &evp_keymgmt_util_try_import,
 164                                          &import_data);
 165             keydata = import_data.keydata;
 166             import_data.keydata = NULL;
 167         }
 168
 169         if (keydata != NULL
 170             && (pkey = evp_keymgmt_util_make_pkey(keymgmt, keydata)) == NULL)
 171             evp_keymgmt_freedata(keymgmt, keydata);
 172
 173         *data->object = pkey;
 174
 175         /*
 176          * evp_keymgmt_util_make_pkey() increments the reference count when
 177          * assigning the EVP_PKEY, so we can free the keymgmt here.
 178          */
 179         EVP_KEYMGMT_free(keymgmt);
 180     }
 181     /*
 182      * We successfully looked through, |*ctx->object| determines if we
 183      * actually found something.
 184      */
 185     return (*data->object != NULL);
 186 }
 187
 188 static void decoder_clean_pkey_construct_arg(void *construct_data)
 189 {
 190     struct decoder_pkey_data_st *data = construct_data;
 191
 192     if (data != NULL) {
 193         sk_EVP_KEYMGMT_pop_free(data->keymgmts, EVP_KEYMGMT_free);
 194         OPENSSL_free(data->propq);
 195         OPENSSL_free(data->object_type);
 196         OPENSSL_free(data);
 197     }
 198 }
 199
 200 struct collect_data_st {
 201     OSSL_LIB_CTX *libctx;
 202     OSSL_DECODER_CTX *ctx;
 203
 204     const char *keytype; /* the keytype requested, if any */
 205     int keytype_id; /* if keytype_resolved is set, keymgmt name_id; else 0 */
 206     int sm2_id;     /* if keytype_resolved is set and EC, SM2 name_id; else 0 */
 207     int total;      /* number of matching results */
 208     char error_occurred;
 209     char keytype_resolved;
 210
 211     STACK_OF(EVP_KEYMGMT) *keymgmts;
 212 };
 213
 214 static void collect_decoder_keymgmt(EVP_KEYMGMT *keymgmt, OSSL_DECODER *decoder,
 215                                     void *provctx, struct collect_data_st *data)
 216 {
 217     void *decoderctx = NULL;
 218     OSSL_DECODER_INSTANCE *di = NULL;
 219
 220     /*
 221      * We already checked the EVP_KEYMGMT is applicable in check_keymgmt so we
 222      * don't check it again here.
 223      */
 224
 225     if (keymgmt->name_id != decoder->base.id)
 226         /* Mismatch is not an error, continue. */
 227         return;
 228
 229     if ((decoderctx = decoder->newctx(provctx)) == NULL) {
 230         data->error_occurred = 1;
 231         return;
 232     }
 233
 234     if ((di = ossl_decoder_instance_new(decoder, decoderctx)) == NULL) {
 235         decoder->freectx(decoderctx);
 236         data->error_occurred = 1;
 237         return;
 238     }
 239
 240     OSSL_TRACE_BEGIN(DECODER) {
 241         BIO_printf(trc_out,
 242                    "(ctx %p) Checking out decoder %p:\n"
 243                    "    %s with %s\n",
 244                    (void *)data->ctx, (void *)decoder,
 245                    OSSL_DECODER_get0_name(decoder),
 246                    OSSL_DECODER_get0_properties(decoder));
 247     } OSSL_TRACE_END(DECODER);
 248
 249     if (!ossl_decoder_ctx_add_decoder_inst(data->ctx, di)) {
 250         ossl_decoder_instance_free(di);
 251         data->error_occurred = 1;
 252         return;
 253     }
 254
 255     ++data->total;
 256 }
 257
 258 static void collect_decoder(OSSL_DECODER *decoder, void *arg)
 259 {
 260     struct collect_data_st *data = arg;
 261     STACK_OF(EVP_KEYMGMT) *keymgmts = data->keymgmts;
 262     int i, end_i;
 263     EVP_KEYMGMT *keymgmt;
 264     const OSSL_PROVIDER *prov;
 265     void *provctx;
 266
 267     if (data->error_occurred)
 268         return;
 269
 270     prov = OSSL_DECODER_get0_provider(decoder);
 271     provctx = OSSL_PROVIDER_get0_provider_ctx(prov);
 272
 273     /*
 274      * Either the caller didn't give us a selection, or if they did, the decoder
 275      * must tell us if it supports that selection to be accepted. If the decoder
 276      * doesn't have |does_selection|, it's seen as taking anything.
 277      */
 278     if (decoder->does_selection != NULL
 279             && !decoder->does_selection(provctx, data->ctx->selection))
 280         return;
 281
 282     OSSL_TRACE_BEGIN(DECODER) {
 283         BIO_printf(trc_out,
 284                    "(ctx %p) Checking out decoder %p:\n"
 285                    "    %s with %s\n",
 286                    (void *)data->ctx, (void *)decoder,
 287                    OSSL_DECODER_get0_name(decoder),
 288                    OSSL_DECODER_get0_properties(decoder));
 289     } OSSL_TRACE_END(DECODER);
 290
 291     end_i = sk_EVP_KEYMGMT_num(keymgmts);
 292     for (i = 0; i < end_i; ++i) {
 293         keymgmt = sk_EVP_KEYMGMT_value(keymgmts, i);
 294
 295         collect_decoder_keymgmt(keymgmt, decoder, provctx, data);
 296         if (data->error_occurred)
 297             return;
 298     }
 299 }
 300
 301 /*
 302  * Is this EVP_KEYMGMT applicable given the key type given in the call to
 303  * ossl_decoder_ctx_setup_for_pkey (if any)?
 304  */
 305 static int check_keymgmt(EVP_KEYMGMT *keymgmt, struct collect_data_st *data)
 306 {
 307     /* If no keytype was specified, everything matches. */
 308     if (data->keytype == NULL)
 309         return 1;
 310
 311     if (!data->keytype_resolved) {
 312         /* We haven't cached the IDs from the keytype string yet. */
 313         OSSL_NAMEMAP *namemap = ossl_namemap_stored(data->libctx);
 314         data->keytype_id = ossl_namemap_name2num(namemap, data->keytype);
 315
 316         /*
 317          * If keytype is a value ambiguously used for both EC and SM2,
 318          * collect the ID for SM2 as well.
 319          */
 320         if (data->keytype_id != 0
 321             && (strcmp(data->keytype, "id-ecPublicKey") == 0
 322                 || strcmp(data->keytype, "1.2.840.10045.2.1") == 0))
 323             data->sm2_id = ossl_namemap_name2num(namemap, "SM2");
 324
 325         /*
 326          * If keytype_id is zero the name was not found, but we still
 327          * set keytype_resolved to avoid trying all this again.
 328          */
 329         data->keytype_resolved = 1;
 330     }
 331
 332     /* Specified keytype could not be resolved, so nothing matches. */
 333     if (data->keytype_id == 0)
 334         return 0;
 335
 336     /* Does not match the keytype specified, so skip. */
 337     if (keymgmt->name_id != data->keytype_id
 338         && keymgmt->name_id != data->sm2_id)
 339         return 0;
 340
 341     return 1;
 342 }
 343
 344 static void collect_keymgmt(EVP_KEYMGMT *keymgmt, void *arg)
 345 {
 346     struct collect_data_st *data = arg;
 347
 348     if (!check_keymgmt(keymgmt, data))
 349         return;
 350
 351     /*
 352      * We have to ref EVP_KEYMGMT here because in the success case,
 353      * data->keymgmts is referenced by the constructor we register in the
 354      * OSSL_DECODER_CTX. The registered cleanup function
 355      * (decoder_clean_pkey_construct_arg) unrefs every element of the stack and
 356      * frees it.
 357      */
 358     if (!EVP_KEYMGMT_up_ref(keymgmt))
 359         return;
 360
 361     if (sk_EVP_KEYMGMT_push(data->keymgmts, keymgmt) <= 0) {
 362         EVP_KEYMGMT_free(keymgmt);
 363         data->error_occurred = 1;
 364     }
 365 }
 366
 367 /*
 368  * This function does the actual binding of decoders to the OSSL_DECODER_CTX. It
 369  * searches for decoders matching 'keytype', which is a string like "RSA", "DH",
 370  * etc. If 'keytype' is NULL, decoders for all keytypes are bound.
 371  */
 372 int ossl_decoder_ctx_setup_for_pkey(OSSL_DECODER_CTX *ctx,
 373                                     EVP_PKEY **pkey, const char *keytype,
 374                                     OSSL_LIB_CTX *libctx,
 375                                     const char *propquery)
 376 {
 377     int ok = 0;
 378     struct decoder_pkey_data_st *process_data = NULL;
 379     struct collect_data_st collect_data = { NULL };
 380     STACK_OF(EVP_KEYMGMT) *keymgmts = NULL;
 381
 382     OSSL_TRACE_BEGIN(DECODER) {
 383         const char *input_type = ctx->start_input_type;
 384         const char *input_structure = ctx->input_structure;
 385
 386         BIO_printf(trc_out,
 387                    "(ctx %p) Looking for decoders producing %s%s%s%s%s%s\n",
 388                    (void *)ctx,
 389                    keytype != NULL ? keytype : "",
 390                    keytype != NULL ? " keys" : "keys of any type",
 391                    input_type != NULL ? " from " : "",
 392                    input_type != NULL ? input_type : "",
 393                    input_structure != NULL ? " with " : "",
 394                    input_structure != NULL ? input_structure : "");
 395     } OSSL_TRACE_END(DECODER);
 396
 397     /* Allocate data. */
 398     if ((process_data = OPENSSL_zalloc(sizeof(*process_data))) == NULL
 399         || (propquery != NULL
 400             && (process_data->propq = OPENSSL_strdup(propquery)) == NULL)) {
 401         ERR_raise(ERR_LIB_OSSL_DECODER, ERR_R_MALLOC_FAILURE);
 402         goto err;
 403     }
 404
 405     /* Allocate our list of EVP_KEYMGMTs. */
 406     keymgmts = sk_EVP_KEYMGMT_new_null();
 407     if (keymgmts == NULL) {
 408         ERR_raise(ERR_LIB_OSSL_DECODER, ERR_R_MALLOC_FAILURE);
 409         goto err;
 410     }
 411
 412     process_data->object    = (void **)pkey;
 413     process_data->libctx    = libctx;
 414     process_data->selection = ctx->selection;
 415     process_data->keymgmts  = keymgmts;
 416
 417     /*
 418      * Enumerate all keymgmts into a stack.
 419      *
 420      * We could nest EVP_KEYMGMT_do_all_provided inside
 421      * OSSL_DECODER_do_all_provided or vice versa but these functions become
 422      * bottlenecks if called repeatedly, which is why we collect the
 423      * EVP_KEYMGMTs into a stack here and call both functions only once.
 424      *
 425      * We resolve the keytype string to a name ID so we don't have to resolve it
 426      * multiple times, avoiding repeated calls to EVP_KEYMGMT_is_a, which is a
 427      * performance bottleneck. However, we do this lazily on the first call to
 428      * collect_keymgmt made by EVP_KEYMGMT_do_all_provided, rather than do it
 429      * upfront, as this ensures that the names for all loaded providers have
 430      * been registered by the time we try to resolve the keytype string.
 431      */
 432     collect_data.ctx        = ctx;
 433     collect_data.libctx     = libctx;
 434     collect_data.keymgmts   = keymgmts;
 435     collect_data.keytype    = keytype;
 436     EVP_KEYMGMT_do_all_provided(libctx, collect_keymgmt, &collect_data);
 437
 438     if (collect_data.error_occurred)
 439         goto err;
 440
 441     /* Enumerate all matching decoders. */
 442     OSSL_DECODER_do_all_provided(libctx, collect_decoder, &collect_data);
 443
 444     if (collect_data.error_occurred)
 445         goto err;
 446
 447     OSSL_TRACE_BEGIN(DECODER) {
 448         BIO_printf(trc_out,
 449                    "(ctx %p) Got %d decoders producing keys\n",
 450                    (void *)ctx, collect_data.total);
 451     } OSSL_TRACE_END(DECODER);
 452
 453     /*
 454      * Finish initializing the decoder context. If one or more decoders matched
 455      * above then the number of decoders attached to the OSSL_DECODER_CTX will
 456      * be nonzero. Else nothing was found and we do nothing.
 457      */
 458     if (OSSL_DECODER_CTX_get_num_decoders(ctx) != 0) {
 459         if (!OSSL_DECODER_CTX_set_construct(ctx, decoder_construct_pkey)
 460             || !OSSL_DECODER_CTX_set_construct_data(ctx, process_data)
 461             || !OSSL_DECODER_CTX_set_cleanup(ctx,
 462                                              decoder_clean_pkey_construct_arg))
 463             goto err;
 464
 465         process_data = NULL; /* Avoid it being freed */
 466     }
 467
 468     ok = 1;
 469  err:
 470     decoder_clean_pkey_construct_arg(process_data);
 471     return ok;
 472 }
 473
 474 OSSL_DECODER_CTX *
 475 OSSL_DECODER_CTX_new_for_pkey(EVP_PKEY **pkey,
 476                               const char *input_type,
 477                               const char *input_structure,
 478                               const char *keytype, int selection,
 479                               OSSL_LIB_CTX *libctx, const char *propquery)
 480 {
 481     OSSL_DECODER_CTX *ctx = NULL;
 482
 483     if ((ctx = OSSL_DECODER_CTX_new()) == NULL) {
 484         ERR_raise(ERR_LIB_OSSL_DECODER, ERR_R_MALLOC_FAILURE);
 485         return NULL;
 486     }
 487
 488     OSSL_TRACE_BEGIN(DECODER) {
 489         BIO_printf(trc_out,
 490                    "(ctx %p) Looking for %s decoders with selection %d\n",
 491                    (void *)ctx, keytype, selection);
 492         BIO_printf(trc_out, "    input type: %s, input structure: %s\n",
 493                    input_type, input_structure);
 494     } OSSL_TRACE_END(DECODER);
 495
 496     if (OSSL_DECODER_CTX_set_input_type(ctx, input_type)
 497         && OSSL_DECODER_CTX_set_input_structure(ctx, input_structure)
 498         && OSSL_DECODER_CTX_set_selection(ctx, selection)
 499         && ossl_decoder_ctx_setup_for_pkey(ctx, pkey, keytype,
 500                                            libctx, propquery)
 501         && OSSL_DECODER_CTX_add_extra(ctx, libctx, propquery)) {
 502         OSSL_TRACE_BEGIN(DECODER) {
 503             BIO_printf(trc_out, "(ctx %p) Got %d decoders\n",
 504                        (void *)ctx, OSSL_DECODER_CTX_get_num_decoders(ctx));
 505         } OSSL_TRACE_END(DECODER);
 506         return ctx;
 507     }
 508
 509     OSSL_DECODER_CTX_free(ctx);
 510     return NULL;
 511 }