providers/default/kdfs/x942kdf.c

   1 /*
   2  * Copyright 2019 The OpenSSL Project Authors. All Rights Reserved.
   3  * Copyright (c) 2019, Oracle and/or its affiliates.  All rights reserved.
   4  *
   5  * Licensed under the Apache License 2.0 (the "License").  You may not use
   6  * this file except in compliance with the License.  You can obtain a copy
   7  * in the file LICENSE in the source distribution or at
   8  * https://www.openssl.org/source/license.html
   9  */
  10
  11 #include "e_os.h"
  12
  13 #ifndef OPENSSL_NO_CMS
  14
  15 # include <stdlib.h>
  16 # include <stdarg.h>
  17 # include <string.h>
  18 # include <openssl/hmac.h>
  19 # include <openssl/cms.h>
  20 # include <openssl/evp.h>
  21 # include <openssl/kdf.h>
  22 # include <openssl/x509.h>
  23 # include <openssl/obj_mac.h>
  24 # include <openssl/core_names.h>
  25 # include "internal/cryptlib.h"
  26 # include "internal/numbers.h"
  27 # include "internal/evp_int.h"
  28 # include "internal/provider_ctx.h"
  29 # include "internal/providercommonerr.h"
  30 # include "internal/provider_algs.h"
  31
  32 # define X942KDF_MAX_INLEN (1 << 30)
  33
  34 static OSSL_OP_kdf_newctx_fn x942kdf_new;
  35 static OSSL_OP_kdf_freectx_fn x942kdf_free;
  36 static OSSL_OP_kdf_reset_fn x942kdf_reset;
  37 static OSSL_OP_kdf_derive_fn x942kdf_derive;
  38 static OSSL_OP_kdf_settable_ctx_params_fn x942kdf_settable_ctx_params;
  39 static OSSL_OP_kdf_set_ctx_params_fn x942kdf_set_ctx_params;
  40 static OSSL_OP_kdf_gettable_ctx_params_fn x942kdf_gettable_ctx_params;
  41 static OSSL_OP_kdf_get_ctx_params_fn x942kdf_get_ctx_params;
  42
  43 typedef struct {
  44     void *provctx;
  45     EVP_MD *md;
  46     unsigned char *secret;
  47     size_t secret_len;
  48     int cek_nid;
  49     unsigned char *ukm;
  50     size_t ukm_len;
  51     size_t dkm_len;
  52 } KDF_X942;
  53
  54 /* A table of allowed wrapping algorithms and the associated output lengths */
  55 static const struct {
  56     int nid;
  57     size_t keklen; /* size in bytes */
  58 } kek_algs[] = {
  59     { NID_id_smime_alg_CMS3DESwrap, 24 },
  60     { NID_id_smime_alg_CMSRC2wrap, 16 },
  61     { NID_id_aes128_wrap, 16 },
  62     { NID_id_aes192_wrap, 24 },
  63     { NID_id_aes256_wrap, 32 },
  64     { NID_id_camellia128_wrap, 16 },
  65     { NID_id_camellia192_wrap, 24 },
  66     { NID_id_camellia256_wrap, 32 }
  67 };
  68
  69 /* Skip past an ASN1 structure: for OBJECT skip content octets too */
  70 static int skip_asn1(unsigned char **pp, long *plen, int exptag)
  71 {
  72     int i, tag, xclass;
  73     long tmplen;
  74     const unsigned char *q = *pp;
  75
  76     i = ASN1_get_object(&q, &tmplen, &tag, &xclass, *plen);
  77     if ((i & 0x80) != 0 || tag != exptag || xclass != V_ASN1_UNIVERSAL)
  78         return 0;
  79     if (tag == V_ASN1_OBJECT)
  80         q += tmplen;
  81     *pp = (unsigned char *)q;
  82     *plen -= q - *pp;
  83     return 1;
  84 }
  85
  86 /*
  87  * Encode the other info structure.
  88  *
  89  *  RFC2631 Section 2.1.2 Contains the following definition for otherinfo
  90  *
  91  *  OtherInfo ::= SEQUENCE {
  92  *      keyInfo KeySpecificInfo,
  93  *      partyAInfo [0] OCTET STRING OPTIONAL,
  94  *      suppPubInfo [2] OCTET STRING
  95  *  }
  96  *
  97  *  KeySpecificInfo ::= SEQUENCE {
  98  *      algorithm OBJECT IDENTIFIER,
  99  *      counter OCTET STRING SIZE (4..4)
 100  *  }
 101  *
 102  * |nid| is the algorithm object identifier.
 103  * |keylen| is the length (in bytes) of the generated KEK. It is stored into
 104  * suppPubInfo (in bits).
 105  * |ukm| is the optional user keying material that is stored into partyAInfo. It
 106  * can be NULL.
 107  * |ukmlen| is the user keying material length (in bytes).
 108  * |der| is the returned encoded data. It must be freed by the caller.
 109  * |der_len| is the returned size of the encoded data.
 110  * |out_ctr| returns a pointer to the counter data which is embedded inside the
 111  * encoded data. This allows the counter bytes to be updated without re-encoding.
 112  *
 113  * Returns: 1 if successfully encoded, or 0 otherwise.
 114  * Assumptions: |der|, |der_len| & |out_ctr| are not NULL.
 115  */
 116 static int x942_encode_otherinfo(int nid, size_t keylen,
 117                                  const unsigned char *ukm, size_t ukmlen,
 118                                  unsigned char **der, size_t *der_len,
 119                                  unsigned char **out_ctr)
 120 {
 121     unsigned char *p, *encoded = NULL;
 122     int ret = 0, encoded_len;
 123     long tlen;
 124     /* "magic" value to check offset is sane */
 125     static unsigned char ctr[4] = { 0x00, 0x00, 0x00, 0x01 };
 126     X509_ALGOR *ksi = NULL;
 127     ASN1_OBJECT *alg_oid = NULL;
 128     ASN1_OCTET_STRING *ctr_oct = NULL, *ukm_oct = NULL;
 129
 130     /* set the KeySpecificInfo - which contains an algorithm oid and counter */
 131     ksi = X509_ALGOR_new();
 132     alg_oid = OBJ_dup(OBJ_nid2obj(nid));
 133     ctr_oct = ASN1_OCTET_STRING_new();
 134     if (ksi == NULL
 135         || alg_oid == NULL
 136         || ctr_oct == NULL
 137         || !ASN1_OCTET_STRING_set(ctr_oct, ctr, sizeof(ctr))
 138         || !X509_ALGOR_set0(ksi, alg_oid, V_ASN1_OCTET_STRING, ctr_oct))
 139         goto err;
 140     /* NULL these as they now belong to ksi */
 141     alg_oid = NULL;
 142     ctr_oct = NULL;
 143
 144     /* Set the optional partyAInfo */
 145     if (ukm != NULL) {
 146         ukm_oct = ASN1_OCTET_STRING_new();
 147         if (ukm_oct == NULL)
 148             goto err;
 149         ASN1_OCTET_STRING_set(ukm_oct, (unsigned char *)ukm, ukmlen);
 150     }
 151     /* Generate the OtherInfo DER data */
 152     encoded_len = CMS_SharedInfo_encode(&encoded, ksi, ukm_oct, keylen);
 153     if (encoded_len <= 0)
 154         goto err;
 155
 156     /* Parse the encoded data to find the offset of the counter data */
 157     p = encoded;
 158     tlen = (long)encoded_len;
 159     if (skip_asn1(&p, &tlen, V_ASN1_SEQUENCE)
 160         && skip_asn1(&p, &tlen, V_ASN1_SEQUENCE)
 161         && skip_asn1(&p, &tlen, V_ASN1_OBJECT)
 162         && skip_asn1(&p, &tlen, V_ASN1_OCTET_STRING)
 163         && CRYPTO_memcmp(p, ctr, 4) == 0) {
 164         *out_ctr = p;
 165         *der = encoded;
 166         *der_len = (size_t)encoded_len;
 167         ret = 1;
 168     }
 169 err:
 170     if (ret != 1)
 171         OPENSSL_free(encoded);
 172     ASN1_OCTET_STRING_free(ctr_oct);
 173     ASN1_OCTET_STRING_free(ukm_oct);
 174     ASN1_OBJECT_free(alg_oid);
 175     X509_ALGOR_free(ksi);
 176     return ret;
 177 }
 178
 179 static int x942kdf_hash_kdm(const EVP_MD *kdf_md,
 180                             const unsigned char *z, size_t z_len,
 181                             const unsigned char *other, size_t other_len,
 182                             unsigned char *ctr,
 183                             unsigned char *derived_key, size_t derived_key_len)
 184 {
 185     int ret = 0, hlen;
 186     size_t counter, out_len, len = derived_key_len;
 187     unsigned char mac[EVP_MAX_MD_SIZE];
 188     unsigned char *out = derived_key;
 189     EVP_MD_CTX *ctx = NULL, *ctx_init = NULL;
 190
 191     if (z_len > X942KDF_MAX_INLEN || other_len > X942KDF_MAX_INLEN
 192             || derived_key_len > X942KDF_MAX_INLEN
 193             || derived_key_len == 0) {
 194         ERR_raise(ERR_LIB_PROV, PROV_R_BAD_LENGTH);
 195         return 0;
 196     }
 197
 198     hlen = EVP_MD_size(kdf_md);
 199     if (hlen <= 0)
 200         return 0;
 201     out_len = (size_t)hlen;
 202
 203     ctx = EVP_MD_CTX_create();
 204     ctx_init = EVP_MD_CTX_create();
 205     if (ctx == NULL || ctx_init == NULL)
 206         goto end;
 207
 208     if (!EVP_DigestInit(ctx_init, kdf_md))
 209         goto end;
 210
 211     for (counter = 1;; counter++) {
 212         /* updating the ctr modifies 4 bytes in the 'other' buffer */
 213         ctr[0] = (unsigned char)((counter >> 24) & 0xff);
 214         ctr[1] = (unsigned char)((counter >> 16) & 0xff);
 215         ctr[2] = (unsigned char)((counter >> 8) & 0xff);
 216         ctr[3] = (unsigned char)(counter & 0xff);
 217
 218         if (!EVP_MD_CTX_copy_ex(ctx, ctx_init)
 219             || !EVP_DigestUpdate(ctx, z, z_len)
 220             || !EVP_DigestUpdate(ctx, other, other_len))
 221             goto end;
 222         if (len >= out_len) {
 223             if (!EVP_DigestFinal_ex(ctx, out, NULL))
 224                 goto end;
 225             out += out_len;
 226             len -= out_len;
 227             if (len == 0)
 228                 break;
 229         } else {
 230             if (!EVP_DigestFinal_ex(ctx, mac, NULL))
 231                 goto end;
 232             memcpy(out, mac, len);
 233             break;
 234         }
 235     }
 236     ret = 1;
 237 end:
 238     EVP_MD_CTX_free(ctx);
 239     EVP_MD_CTX_free(ctx_init);
 240     OPENSSL_cleanse(mac, sizeof(mac));
 241     return ret;
 242 }
 243
 244 static void *x942kdf_new(void *provctx)
 245 {
 246     KDF_X942 *ctx;
 247
 248     if ((ctx = OPENSSL_zalloc(sizeof(*ctx))) == NULL)
 249         ERR_raise(ERR_LIB_PROV, ERR_R_MALLOC_FAILURE);
 250     ctx->provctx = provctx;
 251     return ctx;
 252 }
 253
 254 static void x942kdf_reset(void *vctx)
 255 {
 256     KDF_X942 *ctx = (KDF_X942 *)vctx;
 257
 258     OPENSSL_clear_free(ctx->secret, ctx->secret_len);
 259     OPENSSL_clear_free(ctx->ukm, ctx->ukm_len);
 260     memset(ctx, 0, sizeof(*ctx));
 261 }
 262
 263 static void x942kdf_free(void *vctx)
 264 {
 265     KDF_X942 *ctx = (KDF_X942 *)vctx;
 266
 267     x942kdf_reset(ctx);
 268     EVP_MD_meth_free(ctx->md);
 269     OPENSSL_free(ctx);
 270 }
 271
 272 static int x942kdf_set_buffer(unsigned char **out, size_t *out_len,
 273                               const OSSL_PARAM *p)
 274 {
 275     if (p->data_size == 0 || p->data == NULL)
 276         return 1;
 277
 278     OPENSSL_free(*out);
 279     *out = NULL;
 280     return OSSL_PARAM_get_octet_string(p, (void **)out, 0, out_len);
 281 }
 282
 283 static size_t x942kdf_size(KDF_X942 *ctx)
 284 {
 285     int len;
 286
 287     if (ctx->md == NULL) {
 288         ERR_raise(ERR_LIB_PROV, PROV_R_MISSING_MESSAGE_DIGEST);
 289         return 0;
 290     }
 291     len = EVP_MD_size(ctx->md);
 292     return (len <= 0) ? 0 : (size_t)len;
 293 }
 294
 295 static int x942kdf_derive(void *vctx, unsigned char *key, size_t keylen)
 296 {
 297     KDF_X942 *ctx = (KDF_X942 *)vctx;
 298     int ret = 0;
 299     unsigned char *ctr;
 300     unsigned char *der = NULL;
 301     size_t der_len = 0;
 302
 303     if (ctx->secret == NULL) {
 304         ERR_raise(ERR_LIB_PROV, PROV_R_MISSING_SECRET);
 305         return 0;
 306     }
 307     if (ctx->md == NULL) {
 308         ERR_raise(ERR_LIB_PROV, PROV_R_MISSING_MESSAGE_DIGEST);
 309         return 0;
 310     }
 311     if (ctx->cek_nid == NID_undef) {
 312         ERR_raise(ERR_LIB_PROV, PROV_R_MISSING_CEK_ALG);
 313         return 0;
 314     }
 315     if (ctx->ukm != NULL && ctx->ukm_len >= X942KDF_MAX_INLEN) {
 316         /*
 317          * Note the ukm length MUST be 512 bits.
 318          * For backwards compatibility the old check is being done.
 319          */
 320         ERR_raise(ERR_LIB_PROV, PROV_R_INAVLID_UKM_LENGTH);
 321         return 0;
 322     }
 323     if (keylen != ctx->dkm_len) {
 324         ERR_raise(ERR_LIB_PROV, PROV_R_MISSING_CEK_ALG);
 325         return 0;
 326     }
 327     /* generate the otherinfo der */
 328     if (!x942_encode_otherinfo(ctx->cek_nid, ctx->dkm_len,
 329                                ctx->ukm, ctx->ukm_len,
 330                                &der, &der_len, &ctr)) {
 331         ERR_raise(ERR_LIB_PROV, PROV_R_BAD_ENCODING);
 332         return 0;
 333     }
 334     ret = x942kdf_hash_kdm(ctx->md, ctx->secret, ctx->secret_len,
 335                            der, der_len, ctr, key, keylen);
 336     OPENSSL_free(der);
 337     return ret;
 338 }
 339
 340 static int x942kdf_set_ctx_params(void *vctx, const OSSL_PARAM params[])
 341 {
 342     const OSSL_PARAM *p;
 343     KDF_X942 *ctx = vctx;
 344     EVP_MD *md;
 345     const char *properties = NULL;
 346     size_t i;
 347
 348     /* Grab search properties, this should be before the digest lookup */
 349     if ((p = OSSL_PARAM_locate_const(params, OSSL_KDF_PARAM_PROPERTIES))
 350         != NULL) {
 351         if (p->data_type != OSSL_PARAM_UTF8_STRING)
 352             return 0;
 353         properties = p->data;
 354     }
 355     /* Handle aliasing of digest parameter names */
 356     if ((p = OSSL_PARAM_locate_const(params, OSSL_KDF_PARAM_DIGEST)) != NULL) {
 357         if (p->data_type != OSSL_PARAM_UTF8_STRING)
 358             return 0;
 359         md = EVP_MD_fetch(PROV_LIBRARY_CONTEXT_OF(ctx->provctx), p->data,
 360                           properties);
 361         if (md == NULL) {
 362             ERR_raise(ERR_LIB_PROV, PROV_R_INVALID_DIGEST);
 363             return 0;
 364         }
 365         EVP_MD_meth_free(ctx->md);
 366         ctx->md = md;
 367     }
 368
 369     if ((p = OSSL_PARAM_locate_const(params, OSSL_KDF_PARAM_SECRET)) != NULL
 370         || (p = OSSL_PARAM_locate_const(params, OSSL_KDF_PARAM_KEY)) != NULL)
 371         if (!x942kdf_set_buffer(&ctx->secret, &ctx->secret_len, p))
 372             return 0;
 373
 374     if ((p = OSSL_PARAM_locate_const(params, OSSL_KDF_PARAM_UKM)) != NULL)
 375         if (!x942kdf_set_buffer(&ctx->ukm, &ctx->ukm_len, p))
 376             return 0;
 377
 378     if ((p = OSSL_PARAM_locate_const(params, OSSL_KDF_PARAM_CEK_ALG)) != NULL) {
 379         if (p->data_type != OSSL_PARAM_UTF8_STRING)
 380             return 0;
 381         ctx->cek_nid = OBJ_sn2nid(p->data);
 382         for (i = 0; i < OSSL_NELEM(kek_algs); i++)
 383             if (kek_algs[i].nid == ctx->cek_nid)
 384                 goto cek_found;
 385         ERR_raise(ERR_LIB_PROV, PROV_R_UNSUPPORTED_CEK_ALG);
 386         return 0;
 387 cek_found:
 388         ctx->dkm_len = kek_algs[i].keklen;
 389     }
 390     return 1;
 391 }
 392
 393 static const OSSL_PARAM *x942kdf_settable_ctx_params(void)
 394 {
 395     static const OSSL_PARAM known_settable_ctx_params[] = {
 396         OSSL_PARAM_utf8_string(OSSL_KDF_PARAM_PROPERTIES, NULL, 0),
 397         OSSL_PARAM_utf8_string(OSSL_KDF_PARAM_DIGEST, NULL, 0),
 398         OSSL_PARAM_octet_string(OSSL_KDF_PARAM_SECRET, NULL, 0),
 399         OSSL_PARAM_octet_string(OSSL_KDF_PARAM_KEY, NULL, 0),
 400         OSSL_PARAM_octet_string(OSSL_KDF_PARAM_UKM, NULL, 0),
 401         OSSL_PARAM_utf8_string(OSSL_KDF_PARAM_CEK_ALG, NULL, 0),
 402         OSSL_PARAM_END
 403     };
 404     return known_settable_ctx_params;
 405 }
 406
 407 static int x942kdf_get_ctx_params(void *vctx, OSSL_PARAM params[])
 408 {
 409     KDF_X942 *ctx = (KDF_X942 *)vctx;
 410     OSSL_PARAM *p;
 411
 412     if ((p = OSSL_PARAM_locate(params, OSSL_KDF_PARAM_SIZE)) != NULL)
 413         return OSSL_PARAM_set_size_t(p, x942kdf_size(ctx));
 414     return -2;
 415 }
 416
 417 static const OSSL_PARAM *x942kdf_gettable_ctx_params(void)
 418 {
 419     static const OSSL_PARAM known_gettable_ctx_params[] = {
 420         OSSL_PARAM_size_t(OSSL_KDF_PARAM_SIZE, NULL),
 421         OSSL_PARAM_END
 422     };
 423     return known_gettable_ctx_params;
 424 }
 425
 426 const OSSL_DISPATCH kdf_x942_kdf_functions[] = {
 427     { OSSL_FUNC_KDF_NEWCTX, (void(*)(void))x942kdf_new },
 428     { OSSL_FUNC_KDF_FREECTX, (void(*)(void))x942kdf_free },
 429     { OSSL_FUNC_KDF_RESET, (void(*)(void))x942kdf_reset },
 430     { OSSL_FUNC_KDF_DERIVE, (void(*)(void))x942kdf_derive },
 431     { OSSL_FUNC_KDF_SETTABLE_CTX_PARAMS,
 432       (void(*)(void))x942kdf_settable_ctx_params },
 433     { OSSL_FUNC_KDF_SET_CTX_PARAMS, (void(*)(void))x942kdf_set_ctx_params },
 434     { OSSL_FUNC_KDF_GETTABLE_CTX_PARAMS,
 435       (void(*)(void))x942kdf_gettable_ctx_params },
 436     { OSSL_FUNC_KDF_GET_CTX_PARAMS, (void(*)(void))x942kdf_get_ctx_params },
 437     { 0, NULL }
 438 };
 439
 440 #endif /* OPENSSL_NO_CMS */