providers/implementations/signature/dsa.c

   1 /*
   2  * Copyright 2019 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 <string.h>
  11
  12 #include <openssl/crypto.h>
  13 #include <openssl/core_numbers.h>
  14 #include <openssl/core_names.h>
  15 #include <openssl/err.h>
  16 #include <openssl/dsa.h>
  17 #include <openssl/params.h>
  18 #include <openssl/evp.h>
  19 #include "internal/nelem.h"
  20 #include "internal/sizes.h"
  21 #include "prov/providercommonerr.h"
  22 #include "prov/implementations.h"
  23 #include "prov/provider_ctx.h"
  24 #include "crypto/dsa.h"
  25
  26 static OSSL_OP_signature_newctx_fn dsa_newctx;
  27 static OSSL_OP_signature_sign_init_fn dsa_signature_init;
  28 static OSSL_OP_signature_verify_init_fn dsa_signature_init;
  29 static OSSL_OP_signature_sign_fn dsa_sign;
  30 static OSSL_OP_signature_verify_fn dsa_verify;
  31 static OSSL_OP_signature_digest_sign_init_fn dsa_digest_signverify_init;
  32 static OSSL_OP_signature_digest_sign_update_fn dsa_digest_signverify_update;
  33 static OSSL_OP_signature_digest_sign_final_fn dsa_digest_sign_final;
  34 static OSSL_OP_signature_digest_verify_init_fn dsa_digest_signverify_init;
  35 static OSSL_OP_signature_digest_verify_update_fn dsa_digest_signverify_update;
  36 static OSSL_OP_signature_digest_verify_final_fn dsa_digest_verify_final;
  37 static OSSL_OP_signature_freectx_fn dsa_freectx;
  38 static OSSL_OP_signature_dupctx_fn dsa_dupctx;
  39 static OSSL_OP_signature_get_ctx_params_fn dsa_get_ctx_params;
  40 static OSSL_OP_signature_gettable_ctx_params_fn dsa_gettable_ctx_params;
  41 static OSSL_OP_signature_set_ctx_params_fn dsa_set_ctx_params;
  42 static OSSL_OP_signature_settable_ctx_params_fn dsa_settable_ctx_params;
  43 static OSSL_OP_signature_get_ctx_md_params_fn dsa_get_ctx_md_params;
  44 static OSSL_OP_signature_gettable_ctx_md_params_fn dsa_gettable_ctx_md_params;
  45 static OSSL_OP_signature_set_ctx_md_params_fn dsa_set_ctx_md_params;
  46 static OSSL_OP_signature_settable_ctx_md_params_fn dsa_settable_ctx_md_params;
  47
  48 /*
  49  * What's passed as an actual key is defined by the KEYMGMT interface.
  50  * We happen to know that our KEYMGMT simply passes DSA structures, so
  51  * we use that here too.
  52  */
  53
  54 typedef struct {
  55     OPENSSL_CTX *libctx;
  56     DSA *dsa;
  57     size_t mdsize;
  58     char mdname[OSSL_MAX_NAME_SIZE];
  59
  60     /* The Algorithm Identifier of the combined signature agorithm */
  61     unsigned char aid[OSSL_MAX_ALGORITHM_ID_SIZE];
  62     size_t  aid_len;
  63
  64     /* main digest */
  65     EVP_MD *md;
  66     EVP_MD_CTX *mdctx;
  67 } PROV_DSA_CTX;
  68
  69 static void *dsa_newctx(void *provctx)
  70 {
  71     PROV_DSA_CTX *pdsactx = OPENSSL_zalloc(sizeof(PROV_DSA_CTX));
  72
  73     if (pdsactx == NULL)
  74         return NULL;
  75
  76     pdsactx->libctx = PROV_LIBRARY_CONTEXT_OF(provctx);
  77     return pdsactx;
  78 }
  79
  80 static int dsa_signature_init(void *vpdsactx, void *vdsa)
  81 {
  82     PROV_DSA_CTX *pdsactx = (PROV_DSA_CTX *)vpdsactx;
  83
  84     if (pdsactx == NULL || vdsa == NULL || !DSA_up_ref(vdsa))
  85         return 0;
  86     DSA_free(pdsactx->dsa);
  87     pdsactx->dsa = vdsa;
  88     return 1;
  89 }
  90
  91 static int dsa_sign(void *vpdsactx, unsigned char *sig, size_t *siglen,
  92                     size_t sigsize, const unsigned char *tbs, size_t tbslen)
  93 {
  94     PROV_DSA_CTX *pdsactx = (PROV_DSA_CTX *)vpdsactx;
  95     int ret;
  96     unsigned int sltmp;
  97     size_t dsasize = DSA_size(pdsactx->dsa);
  98
  99     if (sig == NULL) {
 100         *siglen = dsasize;
 101         return 1;
 102     }
 103
 104     if (sigsize < (size_t)dsasize)
 105         return 0;
 106
 107     if (pdsactx->mdsize != 0 && tbslen != pdsactx->mdsize)
 108         return 0;
 109
 110     ret = dsa_sign_int(pdsactx->libctx, 0, tbs, tbslen, sig, &sltmp,
 111                        pdsactx->dsa);
 112     if (ret <= 0)
 113         return 0;
 114
 115     *siglen = sltmp;
 116     return 1;
 117 }
 118
 119 static int dsa_verify(void *vpdsactx, const unsigned char *sig, size_t siglen,
 120                       const unsigned char *tbs, size_t tbslen)
 121 {
 122     PROV_DSA_CTX *pdsactx = (PROV_DSA_CTX *)vpdsactx;
 123
 124     if (pdsactx->mdsize != 0 && tbslen != pdsactx->mdsize)
 125         return 0;
 126
 127     return DSA_verify(0, tbs, tbslen, sig, siglen, pdsactx->dsa);
 128 }
 129
 130 static int get_md_nid(const EVP_MD *md)
 131 {
 132     /*
 133      * Because the DSA library deals with NIDs, we need to translate.
 134      * We do so using EVP_MD_is_a(), and therefore need a name to NID
 135      * map.
 136      */
 137     static const OSSL_ITEM name_to_nid[] = {
 138         { NID_sha1,   OSSL_DIGEST_NAME_SHA1   },
 139         { NID_sha224, OSSL_DIGEST_NAME_SHA2_224 },
 140         { NID_sha256, OSSL_DIGEST_NAME_SHA2_256 },
 141         { NID_sha384, OSSL_DIGEST_NAME_SHA2_384 },
 142         { NID_sha512, OSSL_DIGEST_NAME_SHA2_512 },
 143         { NID_sha3_224, OSSL_DIGEST_NAME_SHA3_224 },
 144         { NID_sha3_256, OSSL_DIGEST_NAME_SHA3_256 },
 145         { NID_sha3_384, OSSL_DIGEST_NAME_SHA3_384 },
 146         { NID_sha3_512, OSSL_DIGEST_NAME_SHA3_512 },
 147     };
 148     size_t i;
 149     int mdnid = NID_undef;
 150
 151     if (md == NULL)
 152         goto end;
 153
 154     for (i = 0; i < OSSL_NELEM(name_to_nid); i++) {
 155         if (EVP_MD_is_a(md, name_to_nid[i].ptr)) {
 156             mdnid = (int)name_to_nid[i].id;
 157             break;
 158         }
 159     }
 160
 161     if (mdnid == NID_undef)
 162         ERR_raise(ERR_LIB_PROV, PROV_R_INVALID_DIGEST);
 163
 164  end:
 165     return mdnid;
 166 }
 167
 168 static int dsa_digest_signverify_init(void *vpdsactx, const char *mdname,
 169                                       const char *props, void *vdsa)
 170 {
 171     PROV_DSA_CTX *pdsactx = (PROV_DSA_CTX *)vpdsactx;
 172     size_t algorithmidentifier_len = 0;
 173     const unsigned char *algorithmidentifier;
 174
 175     EVP_MD_CTX_free(pdsactx->mdctx);
 176     EVP_MD_free(pdsactx->md);
 177     pdsactx->mdctx = NULL;
 178     pdsactx->mdsize = 0;
 179     pdsactx->md = NULL;
 180
 181     if (!dsa_signature_init(vpdsactx, vdsa))
 182         return 0;
 183
 184     pdsactx->md = EVP_MD_fetch(pdsactx->libctx, mdname, props);
 185     algorithmidentifier =
 186         dsa_algorithmidentifier_encoding(get_md_nid(pdsactx->md),
 187                                          &algorithmidentifier_len);
 188
 189     if (algorithmidentifier == NULL)
 190         goto error;
 191
 192     pdsactx->mdsize = EVP_MD_size(pdsactx->md);
 193     pdsactx->mdctx = EVP_MD_CTX_new();
 194     if (pdsactx->mdctx == NULL)
 195         goto error;
 196
 197     memcpy(pdsactx->aid, algorithmidentifier, algorithmidentifier_len);
 198     pdsactx->aid_len = algorithmidentifier_len;
 199
 200     if (!EVP_DigestInit_ex(pdsactx->mdctx, pdsactx->md, NULL))
 201         goto error;
 202
 203     return 1;
 204
 205  error:
 206     EVP_MD_CTX_free(pdsactx->mdctx);
 207     EVP_MD_free(pdsactx->md);
 208     pdsactx->mdctx = NULL;
 209     pdsactx->md = NULL;
 210     return 0;
 211 }
 212
 213 int dsa_digest_signverify_update(void *vpdsactx, const unsigned char *data,
 214                                  size_t datalen)
 215 {
 216     PROV_DSA_CTX *pdsactx = (PROV_DSA_CTX *)vpdsactx;
 217
 218     if (pdsactx == NULL || pdsactx->mdctx == NULL)
 219         return 0;
 220
 221     return EVP_DigestUpdate(pdsactx->mdctx, data, datalen);
 222 }
 223
 224 int dsa_digest_sign_final(void *vpdsactx, unsigned char *sig, size_t *siglen,
 225                           size_t sigsize)
 226 {
 227     PROV_DSA_CTX *pdsactx = (PROV_DSA_CTX *)vpdsactx;
 228     unsigned char digest[EVP_MAX_MD_SIZE];
 229     unsigned int dlen = 0;
 230
 231     if (pdsactx == NULL || pdsactx->mdctx == NULL)
 232         return 0;
 233
 234     /*
 235      * If sig is NULL then we're just finding out the sig size. Other fields
 236      * are ignored. Defer to dsa_sign.
 237      */
 238     if (sig != NULL) {
 239         /*
 240          * TODO(3.0): There is the possibility that some externally provided
 241          * digests exceed EVP_MAX_MD_SIZE. We should probably handle that somehow -
 242          * but that problem is much larger than just in DSA.
 243          */
 244         if (!EVP_DigestFinal_ex(pdsactx->mdctx, digest, &dlen))
 245             return 0;
 246     }
 247
 248     return dsa_sign(vpdsactx, sig, siglen, sigsize, digest, (size_t)dlen);
 249 }
 250
 251
 252 int dsa_digest_verify_final(void *vpdsactx, const unsigned char *sig,
 253                             size_t siglen)
 254 {
 255     PROV_DSA_CTX *pdsactx = (PROV_DSA_CTX *)vpdsactx;
 256     unsigned char digest[EVP_MAX_MD_SIZE];
 257     unsigned int dlen = 0;
 258
 259     if (pdsactx == NULL || pdsactx->mdctx == NULL)
 260         return 0;
 261
 262     /*
 263      * TODO(3.0): There is the possibility that some externally provided
 264      * digests exceed EVP_MAX_MD_SIZE. We should probably handle that somehow -
 265      * but that problem is much larger than just in DSA.
 266      */
 267     if (!EVP_DigestFinal_ex(pdsactx->mdctx, digest, &dlen))
 268         return 0;
 269
 270     return dsa_verify(vpdsactx, sig, siglen, digest, (size_t)dlen);
 271 }
 272
 273 static void dsa_freectx(void *vpdsactx)
 274 {
 275     PROV_DSA_CTX *pdsactx = (PROV_DSA_CTX *)vpdsactx;
 276
 277     DSA_free(pdsactx->dsa);
 278     EVP_MD_CTX_free(pdsactx->mdctx);
 279     EVP_MD_free(pdsactx->md);
 280
 281     OPENSSL_free(pdsactx);
 282 }
 283
 284 static void *dsa_dupctx(void *vpdsactx)
 285 {
 286     PROV_DSA_CTX *srcctx = (PROV_DSA_CTX *)vpdsactx;
 287     PROV_DSA_CTX *dstctx;
 288
 289     dstctx = OPENSSL_zalloc(sizeof(*srcctx));
 290     if (dstctx == NULL)
 291         return NULL;
 292
 293     *dstctx = *srcctx;
 294     dstctx->dsa = NULL;
 295     dstctx->md = NULL;
 296     dstctx->mdctx = NULL;
 297
 298     if (srcctx->dsa != NULL && !DSA_up_ref(srcctx->dsa))
 299         goto err;
 300     dstctx->dsa = srcctx->dsa;
 301
 302     if (srcctx->md != NULL && !EVP_MD_up_ref(srcctx->md))
 303         goto err;
 304     dstctx->md = srcctx->md;
 305
 306     if (srcctx->mdctx != NULL) {
 307         dstctx->mdctx = EVP_MD_CTX_new();
 308         if (dstctx->mdctx == NULL
 309                 || !EVP_MD_CTX_copy_ex(dstctx->mdctx, srcctx->mdctx))
 310             goto err;
 311     }
 312
 313     return dstctx;
 314  err:
 315     dsa_freectx(dstctx);
 316     return NULL;
 317 }
 318
 319 static int dsa_get_ctx_params(void *vpdsactx, OSSL_PARAM *params)
 320 {
 321     PROV_DSA_CTX *pdsactx = (PROV_DSA_CTX *)vpdsactx;
 322     OSSL_PARAM *p;
 323
 324     if (pdsactx == NULL || params == NULL)
 325         return 0;
 326
 327     p = OSSL_PARAM_locate(params, OSSL_SIGNATURE_PARAM_ALGORITHM_ID);
 328     if (p != NULL
 329         && !OSSL_PARAM_set_octet_string(p, pdsactx->aid, pdsactx->aid_len))
 330         return 0;
 331
 332     p = OSSL_PARAM_locate(params, OSSL_SIGNATURE_PARAM_DIGEST);
 333     if (p != NULL && !OSSL_PARAM_set_utf8_string(p, pdsactx->md == NULL
 334                                                     ? pdsactx->mdname
 335                                                     : EVP_MD_name(pdsactx->md)))
 336         return 0;
 337
 338     return 1;
 339 }
 340
 341 static const OSSL_PARAM known_gettable_ctx_params[] = {
 342     OSSL_PARAM_octet_string(OSSL_SIGNATURE_PARAM_ALGORITHM_ID, NULL, 0),
 343     OSSL_PARAM_utf8_string(OSSL_SIGNATURE_PARAM_DIGEST, NULL, 0),
 344     OSSL_PARAM_END
 345 };
 346
 347 static const OSSL_PARAM *dsa_gettable_ctx_params(void)
 348 {
 349     return known_gettable_ctx_params;
 350 }
 351
 352 static int dsa_set_ctx_params(void *vpdsactx, const OSSL_PARAM params[])
 353 {
 354     PROV_DSA_CTX *pdsactx = (PROV_DSA_CTX *)vpdsactx;
 355     const OSSL_PARAM *p;
 356     char *mdname;
 357
 358     if (pdsactx == NULL || params == NULL)
 359         return 0;
 360
 361     if (pdsactx->md != NULL) {
 362         /*
 363          * You cannot set the digest name/size when doing a DigestSign or
 364          * DigestVerify.
 365          */
 366         return 1;
 367     }
 368
 369     /*
 370      * We never actually use the mdname, but we do support getting it later.
 371      * This can be useful for applications that want to know the MD that they
 372      * previously set.
 373      */
 374     p = OSSL_PARAM_locate_const(params, OSSL_SIGNATURE_PARAM_DIGEST);
 375     mdname = pdsactx->mdname;
 376     if (p != NULL
 377             && !OSSL_PARAM_get_utf8_string(p, &mdname, sizeof(pdsactx->mdname)))
 378         return 0;
 379
 380     return 1;
 381 }
 382
 383 static const OSSL_PARAM known_settable_ctx_params[] = {
 384     OSSL_PARAM_utf8_string(OSSL_SIGNATURE_PARAM_DIGEST, NULL, 0),
 385     OSSL_PARAM_END
 386 };
 387
 388 static const OSSL_PARAM *dsa_settable_ctx_params(void)
 389 {
 390     /*
 391      * TODO(3.0): Should this function return a different set of settable ctx
 392      * params if the ctx is being used for a DigestSign/DigestVerify? In that
 393      * case it is not allowed to set the digest size/digest name because the
 394      * digest is explicitly set as part of the init.
 395      */
 396     return known_settable_ctx_params;
 397 }
 398
 399 static int dsa_get_ctx_md_params(void *vpdsactx, OSSL_PARAM *params)
 400 {
 401     PROV_DSA_CTX *pdsactx = (PROV_DSA_CTX *)vpdsactx;
 402
 403     if (pdsactx->mdctx == NULL)
 404         return 0;
 405
 406     return EVP_MD_CTX_get_params(pdsactx->mdctx, params);
 407 }
 408
 409 static const OSSL_PARAM *dsa_gettable_ctx_md_params(void *vpdsactx)
 410 {
 411     PROV_DSA_CTX *pdsactx = (PROV_DSA_CTX *)vpdsactx;
 412
 413     if (pdsactx->md == NULL)
 414         return 0;
 415
 416     return EVP_MD_gettable_ctx_params(pdsactx->md);
 417 }
 418
 419 static int dsa_set_ctx_md_params(void *vpdsactx, const OSSL_PARAM params[])
 420 {
 421     PROV_DSA_CTX *pdsactx = (PROV_DSA_CTX *)vpdsactx;
 422
 423     if (pdsactx->mdctx == NULL)
 424         return 0;
 425
 426     return EVP_MD_CTX_set_params(pdsactx->mdctx, params);
 427 }
 428
 429 static const OSSL_PARAM *dsa_settable_ctx_md_params(void *vpdsactx)
 430 {
 431     PROV_DSA_CTX *pdsactx = (PROV_DSA_CTX *)vpdsactx;
 432
 433     if (pdsactx->md == NULL)
 434         return 0;
 435
 436     return EVP_MD_settable_ctx_params(pdsactx->md);
 437 }
 438
 439 const OSSL_DISPATCH dsa_signature_functions[] = {
 440     { OSSL_FUNC_SIGNATURE_NEWCTX, (void (*)(void))dsa_newctx },
 441     { OSSL_FUNC_SIGNATURE_SIGN_INIT, (void (*)(void))dsa_signature_init },
 442     { OSSL_FUNC_SIGNATURE_SIGN, (void (*)(void))dsa_sign },
 443     { OSSL_FUNC_SIGNATURE_VERIFY_INIT, (void (*)(void))dsa_signature_init },
 444     { OSSL_FUNC_SIGNATURE_VERIFY, (void (*)(void))dsa_verify },
 445     { OSSL_FUNC_SIGNATURE_DIGEST_SIGN_INIT,
 446       (void (*)(void))dsa_digest_signverify_init },
 447     { OSSL_FUNC_SIGNATURE_DIGEST_SIGN_UPDATE,
 448       (void (*)(void))dsa_digest_signverify_update },
 449     { OSSL_FUNC_SIGNATURE_DIGEST_SIGN_FINAL,
 450       (void (*)(void))dsa_digest_sign_final },
 451     { OSSL_FUNC_SIGNATURE_DIGEST_VERIFY_INIT,
 452       (void (*)(void))dsa_digest_signverify_init },
 453     { OSSL_FUNC_SIGNATURE_DIGEST_VERIFY_UPDATE,
 454       (void (*)(void))dsa_digest_signverify_update },
 455     { OSSL_FUNC_SIGNATURE_DIGEST_VERIFY_FINAL,
 456       (void (*)(void))dsa_digest_verify_final },
 457     { OSSL_FUNC_SIGNATURE_FREECTX, (void (*)(void))dsa_freectx },
 458     { OSSL_FUNC_SIGNATURE_DUPCTX, (void (*)(void))dsa_dupctx },
 459     { OSSL_FUNC_SIGNATURE_GET_CTX_PARAMS, (void (*)(void))dsa_get_ctx_params },
 460     { OSSL_FUNC_SIGNATURE_GETTABLE_CTX_PARAMS,
 461       (void (*)(void))dsa_gettable_ctx_params },
 462     { OSSL_FUNC_SIGNATURE_SET_CTX_PARAMS, (void (*)(void))dsa_set_ctx_params },
 463     { OSSL_FUNC_SIGNATURE_SETTABLE_CTX_PARAMS,
 464       (void (*)(void))dsa_settable_ctx_params },
 465     { OSSL_FUNC_SIGNATURE_GET_CTX_MD_PARAMS,
 466       (void (*)(void))dsa_get_ctx_md_params },
 467     { OSSL_FUNC_SIGNATURE_GETTABLE_CTX_MD_PARAMS,
 468       (void (*)(void))dsa_gettable_ctx_md_params },
 469     { OSSL_FUNC_SIGNATURE_SET_CTX_MD_PARAMS,
 470       (void (*)(void))dsa_set_ctx_md_params },
 471     { OSSL_FUNC_SIGNATURE_SETTABLE_CTX_MD_PARAMS,
 472       (void (*)(void))dsa_settable_ctx_md_params },
 473     { 0, NULL }
 474 };