crypto/evp/pmeth_gn.c

   1 /*
   2  * Copyright 2006-2020 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 <stdio.h>
  11 #include <stdlib.h>
  12 #include <openssl/core.h>
  13 #include <openssl/core_names.h>
  14 #include "internal/cryptlib.h"
  15 #include "internal/core.h"
  16 #include <openssl/objects.h>
  17 #include <openssl/evp.h>
  18 #include "crypto/bn.h"
  19 #include "crypto/asn1.h"
  20 #include "crypto/evp.h"
  21 #include "evp_local.h"
  22
  23 #if !defined(FIPS_MODULE) && !defined(OPENSSL_NO_EC)
  24 # define TMP_SM2_HACK
  25 #endif
  26
  27 /* TODO(3.0) remove when provider SM2 key generation is implemented */
  28 #ifdef TMP_SM2_HACK
  29 # include <openssl/ec.h>
  30 # include <openssl/serializer.h>
  31 # include "internal/sizes.h"
  32 #endif
  33
  34 static int gen_init(EVP_PKEY_CTX *ctx, int operation)
  35 {
  36     int ret = 0;
  37
  38     if (ctx == NULL)
  39         goto not_supported;
  40
  41     evp_pkey_ctx_free_old_ops(ctx);
  42     ctx->operation = operation;
  43
  44     if (ctx->keymgmt == NULL || ctx->keymgmt->gen_init == NULL)
  45         goto legacy;
  46
  47 /* TODO remove when provider SM2 key generation is implemented */
  48 #ifdef TMP_SM2_HACK
  49     if (ctx->pmeth != NULL && ctx->pmeth->pkey_id == EVP_PKEY_SM2)
  50         goto legacy;
  51 #endif
  52
  53     switch (operation) {
  54     case EVP_PKEY_OP_PARAMGEN:
  55         ctx->op.keymgmt.genctx =
  56             evp_keymgmt_gen_init(ctx->keymgmt,
  57                                  OSSL_KEYMGMT_SELECT_ALL_PARAMETERS);
  58         break;
  59     case EVP_PKEY_OP_KEYGEN:
  60         ctx->op.keymgmt.genctx =
  61             evp_keymgmt_gen_init(ctx->keymgmt, OSSL_KEYMGMT_SELECT_KEYPAIR);
  62         break;
  63     }
  64
  65     if (ctx->op.keymgmt.genctx == NULL)
  66         ERR_raise(ERR_LIB_EVP, EVP_R_INITIALIZATION_ERROR);
  67     else
  68         ret = 1;
  69     goto end;
  70
  71  legacy:
  72 #ifdef FIPS_MODULE
  73     goto not_supported;
  74 #else
  75     if (ctx->pmeth == NULL
  76         || (operation == EVP_PKEY_OP_PARAMGEN
  77             && ctx->pmeth->paramgen == NULL)
  78         || (operation == EVP_PKEY_OP_KEYGEN
  79             && ctx->pmeth->keygen == NULL))
  80         goto not_supported;
  81
  82     ret = 1;
  83     switch (operation) {
  84     case EVP_PKEY_OP_PARAMGEN:
  85         if (ctx->pmeth->paramgen_init != NULL)
  86             ret = ctx->pmeth->paramgen_init(ctx);
  87         break;
  88     case EVP_PKEY_OP_KEYGEN:
  89         if (ctx->pmeth->keygen_init != NULL)
  90             ret = ctx->pmeth->keygen_init(ctx);
  91         break;
  92     }
  93 #endif
  94
  95  end:
  96     if (ret <= 0 && ctx != NULL) {
  97         evp_pkey_ctx_free_old_ops(ctx);
  98         ctx->operation = EVP_PKEY_OP_UNDEFINED;
  99     }
 100     return ret;
 101
 102  not_supported:
 103     ERR_raise(ERR_LIB_EVP, EVP_R_OPERATION_NOT_SUPPORTED_FOR_THIS_KEYTYPE);
 104     ret = -2;
 105     goto end;
 106 }
 107
 108 int EVP_PKEY_paramgen_init(EVP_PKEY_CTX *ctx)
 109 {
 110     return gen_init(ctx, EVP_PKEY_OP_PARAMGEN);
 111 }
 112
 113 int EVP_PKEY_keygen_init(EVP_PKEY_CTX *ctx)
 114 {
 115     return gen_init(ctx, EVP_PKEY_OP_KEYGEN);
 116 }
 117
 118 static int ossl_callback_to_pkey_gencb(const OSSL_PARAM params[], void *arg)
 119 {
 120     EVP_PKEY_CTX *ctx = arg;
 121     const OSSL_PARAM *param = NULL;
 122     int p = -1, n = -1;
 123
 124     if (ctx->pkey_gencb == NULL)
 125         return 1;                /* No callback?  That's fine */
 126
 127     if ((param = OSSL_PARAM_locate_const(params, OSSL_GEN_PARAM_POTENTIAL))
 128         == NULL
 129         || !OSSL_PARAM_get_int(param, &p))
 130         return 0;
 131     if ((param = OSSL_PARAM_locate_const(params, OSSL_GEN_PARAM_ITERATION))
 132         == NULL
 133         || !OSSL_PARAM_get_int(param, &n))
 134         return 0;
 135
 136     ctx->keygen_info[0] = p;
 137     ctx->keygen_info[1] = n;
 138
 139     return ctx->pkey_gencb(ctx);
 140 }
 141
 142 int EVP_PKEY_gen(EVP_PKEY_CTX *ctx, EVP_PKEY **ppkey)
 143 {
 144     int ret = 0;
 145     OSSL_CALLBACK cb;
 146     EVP_PKEY *allocated_pkey = NULL;
 147     /* Legacy compatible keygen callback info, only used with provider impls */
 148     int gentmp[2];
 149
 150     if (ppkey == NULL)
 151         return -1;
 152
 153     if (ctx == NULL)
 154         goto not_supported;
 155
 156     if ((ctx->operation & EVP_PKEY_OP_TYPE_GEN) == 0)
 157         goto not_initialized;
 158
 159     if (*ppkey == NULL)
 160         *ppkey = allocated_pkey = EVP_PKEY_new();
 161
 162     if (*ppkey == NULL) {
 163         ERR_raise(ERR_LIB_EVP, ERR_R_MALLOC_FAILURE);
 164         return -1;
 165     }
 166
 167     if (ctx->op.keymgmt.genctx == NULL)
 168         goto legacy;
 169
 170     /*
 171      * Asssigning gentmp to ctx->keygen_info is something our legacy
 172      * implementations do.  Because the provider implementations aren't
 173      * allowed to reach into our EVP_PKEY_CTX, we need to provide similar
 174      * space for backward compatibility.  It's ok that we attach a local
 175      * variable, as it should only be useful in the calls down from here.
 176      * This is cleared as soon as it isn't useful any more, i.e. directly
 177      * after the evp_keymgmt_util_gen() call.
 178      */
 179     ctx->keygen_info = gentmp;
 180     ctx->keygen_info_count = 2;
 181
 182     ret = 1;
 183     if (ctx->pkey != NULL) {
 184         EVP_KEYMGMT *tmp_keymgmt = ctx->keymgmt;
 185         void *keydata =
 186             evp_pkey_export_to_provider(ctx->pkey, ctx->libctx,
 187                                         &tmp_keymgmt, ctx->propquery);
 188
 189         if (tmp_keymgmt == NULL)
 190             goto not_supported;
 191         /*
 192          * It's ok if keydata is NULL here.  The backend is expected to deal
 193          * with that as it sees fit.
 194          */
 195         ret = evp_keymgmt_gen_set_template(ctx->keymgmt,
 196                                            ctx->op.keymgmt.genctx, keydata);
 197     }
 198
 199     /*
 200      * the returned value from evp_keymgmt_util_gen() is cached in *ppkey,
 201      * so we so not need to save it, just check it.
 202      */
 203     ret = ret
 204         && (evp_keymgmt_util_gen(*ppkey, ctx->keymgmt, ctx->op.keymgmt.genctx,
 205                                  ossl_callback_to_pkey_gencb, ctx)
 206             != NULL);
 207
 208     ctx->keygen_info = NULL;
 209
 210 #ifndef FIPS_MODULE
 211     /* In case |*ppkey| was originally a legacy key */
 212     if (ret)
 213         evp_pkey_free_legacy(*ppkey);
 214 #endif
 215
 216 /* TODO remove when SM2 key have been cleanly separated from EC keys */
 217 #ifdef TMP_SM2_HACK
 218     /*
 219      * Legacy SM2 keys are implemented as EC_KEY with a twist.  The legacy
 220      * key generation detects the SM2 curve and "magically" changes the pkey
 221      * id accordingly.
 222      * Since we don't have SM2 in the provider implementation, we need to
 223      * downgrade the generated provider side key to a legacy one under the
 224      * same conditions.
 225      *
 226      * THIS IS AN UGLY BUT TEMPORARY HACK
 227      */
 228     {
 229         char curve_name[OSSL_MAX_NAME_SIZE] = "";
 230
 231         if (!EVP_PKEY_get_utf8_string_param(*ppkey, OSSL_PKEY_PARAM_EC_NAME,
 232                                             curve_name, sizeof(curve_name),
 233                                             NULL)
 234             || strcmp(curve_name, "SM2") != 0)
 235             goto end;
 236     }
 237
 238     if (!evp_pkey_downgrade(*ppkey)
 239         || !EVP_PKEY_set_alias_type(*ppkey, EVP_PKEY_SM2))
 240         ret = 0;
 241 #endif
 242     goto end;
 243
 244  legacy:
 245 #ifdef FIPS_MODULE
 246     goto not_supported;
 247 #else
 248     if (ctx->pkey && !evp_pkey_downgrade(ctx->pkey))
 249         goto not_accessible;
 250     switch (ctx->operation) {
 251     case EVP_PKEY_OP_PARAMGEN:
 252         ret = ctx->pmeth->paramgen(ctx, *ppkey);
 253         break;
 254     case EVP_PKEY_OP_KEYGEN:
 255         ret = ctx->pmeth->keygen(ctx, *ppkey);
 256         break;
 257     default:
 258         goto not_supported;
 259     }
 260 #endif
 261
 262  end:
 263     if (ret <= 0) {
 264         if (allocated_pkey != NULL)
 265             *ppkey = NULL;
 266         EVP_PKEY_free(allocated_pkey);
 267     }
 268     return ret;
 269
 270  not_supported:
 271     ERR_raise(ERR_LIB_EVP, EVP_R_OPERATION_NOT_SUPPORTED_FOR_THIS_KEYTYPE);
 272     ret = -2;
 273     goto end;
 274  not_initialized:
 275     ERR_raise(ERR_LIB_EVP, EVP_R_OPERATON_NOT_INITIALIZED);
 276     ret = -1;
 277     goto end;
 278 #ifndef FIPS_MODULE
 279  not_accessible:
 280     ERR_raise(ERR_LIB_EVP, EVP_R_INACCESSIBLE_DOMAIN_PARAMETERS);
 281     ret = -1;
 282     goto end;
 283 #endif
 284 }
 285
 286 int EVP_PKEY_paramgen(EVP_PKEY_CTX *ctx, EVP_PKEY **ppkey)
 287 {
 288     if (ctx->operation != EVP_PKEY_OP_PARAMGEN) {
 289         ERR_raise(ERR_LIB_EVP, EVP_R_OPERATON_NOT_INITIALIZED);
 290         return -1;
 291     }
 292     return EVP_PKEY_gen(ctx, ppkey);
 293 }
 294
 295 int EVP_PKEY_keygen(EVP_PKEY_CTX *ctx, EVP_PKEY **ppkey)
 296 {
 297     if (ctx->operation != EVP_PKEY_OP_KEYGEN) {
 298         ERR_raise(ERR_LIB_EVP, EVP_R_OPERATON_NOT_INITIALIZED);
 299         return -1;
 300     }
 301     return EVP_PKEY_gen(ctx, ppkey);
 302 }
 303
 304 void EVP_PKEY_CTX_set_cb(EVP_PKEY_CTX *ctx, EVP_PKEY_gen_cb *cb)
 305 {
 306     ctx->pkey_gencb = cb;
 307 }
 308
 309 EVP_PKEY_gen_cb *EVP_PKEY_CTX_get_cb(EVP_PKEY_CTX *ctx)
 310 {
 311     return ctx->pkey_gencb;
 312 }
 313
 314 /*
 315  * "translation callback" to call EVP_PKEY_CTX callbacks using BN_GENCB style
 316  * callbacks.
 317  */
 318
 319 static int trans_cb(int a, int b, BN_GENCB *gcb)
 320 {
 321     EVP_PKEY_CTX *ctx = BN_GENCB_get_arg(gcb);
 322     ctx->keygen_info[0] = a;
 323     ctx->keygen_info[1] = b;
 324     return ctx->pkey_gencb(ctx);
 325 }
 326
 327 void evp_pkey_set_cb_translate(BN_GENCB *cb, EVP_PKEY_CTX *ctx)
 328 {
 329     BN_GENCB_set(cb, trans_cb, ctx);
 330 }
 331
 332 int EVP_PKEY_CTX_get_keygen_info(EVP_PKEY_CTX *ctx, int idx)
 333 {
 334     if (idx == -1)
 335         return ctx->keygen_info_count;
 336     if (idx < 0 || idx > ctx->keygen_info_count)
 337         return 0;
 338     return ctx->keygen_info[idx];
 339 }
 340
 341 #ifndef FIPS_MODULE
 342
 343 EVP_PKEY *EVP_PKEY_new_mac_key(int type, ENGINE *e,
 344                                const unsigned char *key, int keylen)
 345 {
 346     EVP_PKEY_CTX *mac_ctx = NULL;
 347     EVP_PKEY *mac_key = NULL;
 348     mac_ctx = EVP_PKEY_CTX_new_id(type, e);
 349     if (!mac_ctx)
 350         return NULL;
 351     if (EVP_PKEY_keygen_init(mac_ctx) <= 0)
 352         goto merr;
 353     if (EVP_PKEY_CTX_set_mac_key(mac_ctx, key, keylen) <= 0)
 354         goto merr;
 355     if (EVP_PKEY_keygen(mac_ctx, &mac_key) <= 0)
 356         goto merr;
 357  merr:
 358     EVP_PKEY_CTX_free(mac_ctx);
 359     return mac_key;
 360 }
 361
 362 #endif /* FIPS_MODULE */
 363
 364 /*- All methods below can also be used in FIPS_MODULE */
 365
 366 static int fromdata_init(EVP_PKEY_CTX *ctx, int operation)
 367 {
 368     if (ctx == NULL || ctx->keytype == NULL)
 369         goto not_supported;
 370
 371     evp_pkey_ctx_free_old_ops(ctx);
 372     if (ctx->keymgmt == NULL)
 373         goto not_supported;
 374
 375     ctx->operation = operation;
 376     return 1;
 377
 378  not_supported:
 379     ctx->operation = EVP_PKEY_OP_UNDEFINED;
 380     ERR_raise(ERR_LIB_EVP, EVP_R_OPERATION_NOT_SUPPORTED_FOR_THIS_KEYTYPE);
 381     return -2;
 382 }
 383
 384 int EVP_PKEY_param_fromdata_init(EVP_PKEY_CTX *ctx)
 385 {
 386     return fromdata_init(ctx, EVP_PKEY_OP_PARAMFROMDATA);
 387 }
 388
 389 int EVP_PKEY_key_fromdata_init(EVP_PKEY_CTX *ctx)
 390 {
 391     return fromdata_init(ctx, EVP_PKEY_OP_KEYFROMDATA);
 392 }
 393
 394 int EVP_PKEY_fromdata(EVP_PKEY_CTX *ctx, EVP_PKEY **ppkey, OSSL_PARAM params[])
 395 {
 396     void *keydata = NULL;
 397     int selection;
 398
 399     if (ctx == NULL || (ctx->operation & EVP_PKEY_OP_TYPE_FROMDATA) == 0) {
 400         ERR_raise(ERR_LIB_EVP, EVP_R_OPERATION_NOT_SUPPORTED_FOR_THIS_KEYTYPE);
 401         return -2;
 402     }
 403
 404     if (ppkey == NULL)
 405         return -1;
 406
 407     if (*ppkey == NULL)
 408         *ppkey = EVP_PKEY_new();
 409
 410     if (*ppkey == NULL) {
 411         ERR_raise(ERR_LIB_EVP, ERR_R_MALLOC_FAILURE);
 412         return -1;
 413     }
 414
 415     if (ctx->operation == EVP_PKEY_OP_PARAMFROMDATA)
 416         selection = OSSL_KEYMGMT_SELECT_ALL_PARAMETERS;
 417     else
 418         selection = OSSL_KEYMGMT_SELECT_ALL;
 419     keydata = evp_keymgmt_util_fromdata(*ppkey, ctx->keymgmt, selection,
 420                                         params);
 421
 422     if (keydata == NULL)
 423         return 0;
 424     /* keydata is cached in *ppkey, so we need not bother with it further */
 425     return 1;
 426 }
 427
 428 /*
 429  * TODO(3.0) Re-evaluate the names, it's possible that we find these to be
 430  * better:
 431  *
 432  * EVP_PKEY_param_settable()
 433  * EVP_PKEY_param_gettable()
 434  */
 435 const OSSL_PARAM *EVP_PKEY_param_fromdata_settable(EVP_PKEY_CTX *ctx)
 436 {
 437     /* We call fromdata_init to get ctx->keymgmt populated */
 438     if (fromdata_init(ctx, EVP_PKEY_OP_UNDEFINED))
 439         return evp_keymgmt_import_types(ctx->keymgmt,
 440                                         OSSL_KEYMGMT_SELECT_ALL_PARAMETERS);
 441     return NULL;
 442 }
 443
 444 const OSSL_PARAM *EVP_PKEY_key_fromdata_settable(EVP_PKEY_CTX *ctx)
 445 {
 446     /* We call fromdata_init to get ctx->keymgmt populated */
 447     if (fromdata_init(ctx, EVP_PKEY_OP_UNDEFINED))
 448         return evp_keymgmt_import_types(ctx->keymgmt,
 449                                         OSSL_KEYMGMT_SELECT_ALL);
 450     return NULL;
 451 }