crypto/x509/x_pubkey.c

   1 /*
   2  * Copyright 1995-2021 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 /*
  11  * DSA low level APIs are deprecated for public use, but still ok for
  12  * internal use.
  13  */
  14 #include "internal/deprecated.h"
  15
  16 #include <stdio.h>
  17 #include "internal/cryptlib.h"
  18 #include <openssl/asn1t.h>
  19 #include <openssl/x509.h>
  20 #include "crypto/asn1.h"
  21 #include "crypto/evp.h"
  22 #include "crypto/x509.h"
  23 #include <openssl/rsa.h>
  24 #include <openssl/dsa.h>
  25 #include <openssl/encoder.h>
  26 #include "internal/provider.h"
  27
  28 struct X509_pubkey_st {
  29     X509_ALGOR *algor;
  30     ASN1_BIT_STRING *public_key;
  31     EVP_PKEY *pkey;
  32
  33     /* extra data for the callback, used by d2i_PUBKEY_ex */
  34     OSSL_LIB_CTX *libctx;
  35     char *propq;
  36 };
  37
  38 static int x509_pubkey_decode(EVP_PKEY **pk, const X509_PUBKEY *key);
  39
  40 static int x509_pubkey_set0_libctx(X509_PUBKEY *x, OSSL_LIB_CTX *libctx,
  41                                    const char *propq)
  42 {
  43     if (x != NULL) {
  44         x->libctx = libctx;
  45         OPENSSL_free(x->propq);
  46         x->propq = NULL;
  47         if (propq != NULL) {
  48             x->propq = OPENSSL_strdup(propq);
  49             if (x->propq == NULL)
  50                 return 0;
  51         }
  52     }
  53     return 1;
  54 }
  55
  56 /* Minor tweak to operation: free up EVP_PKEY */
  57 static int pubkey_cb(int operation, ASN1_VALUE **pval, const ASN1_ITEM *it,
  58                      void *exarg)
  59 {
  60     X509_PUBKEY *pubkey = (X509_PUBKEY *)*pval;
  61
  62     if (operation == ASN1_OP_FREE_POST) {
  63         OPENSSL_free(pubkey->propq);
  64         EVP_PKEY_free(pubkey->pkey);
  65     } else if (operation == ASN1_OP_D2I_POST) {
  66         /* Attempt to decode public key and cache in pubkey structure. */
  67         EVP_PKEY_free(pubkey->pkey);
  68         pubkey->pkey = NULL;
  69         /*
  70          * Opportunistically decode the key but remove any non fatal errors
  71          * from the queue. Subsequent explicit attempts to decode/use the key
  72          * will return an appropriate error.
  73          */
  74         ERR_set_mark();
  75         if (x509_pubkey_decode(&pubkey->pkey, pubkey) == -1) {
  76             ERR_clear_last_mark();
  77             return 0;
  78         }
  79         ERR_pop_to_mark();
  80     } else if (operation == ASN1_OP_DUP_POST) {
  81         X509_PUBKEY *old = exarg;
  82
  83         if (!x509_pubkey_set0_libctx(pubkey, old->libctx, old->propq))
  84             return 0;
  85     }
  86     return 1;
  87 }
  88
  89 ASN1_SEQUENCE_cb(X509_PUBKEY, pubkey_cb) = {
  90         ASN1_SIMPLE(X509_PUBKEY, algor, X509_ALGOR),
  91         ASN1_SIMPLE(X509_PUBKEY, public_key, ASN1_BIT_STRING)
  92 } ASN1_SEQUENCE_END_cb(X509_PUBKEY, X509_PUBKEY)
  93
  94 IMPLEMENT_ASN1_FUNCTIONS(X509_PUBKEY)
  95 IMPLEMENT_ASN1_DUP_FUNCTION(X509_PUBKEY)
  96
  97 /* TODO should better be called X509_PUBKEY_set1 */
  98 int X509_PUBKEY_set(X509_PUBKEY **x, EVP_PKEY *pkey)
  99 {
 100     X509_PUBKEY *pk = NULL;
 101
 102     if (x == NULL || pkey == NULL) {
 103         ERR_raise(ERR_LIB_X509, ERR_R_PASSED_NULL_PARAMETER);
 104         return 0;
 105     }
 106
 107     if (pkey->ameth != NULL) {
 108         if ((pk = X509_PUBKEY_new()) == NULL) {
 109             ERR_raise(ERR_LIB_X509, ERR_R_MALLOC_FAILURE);
 110             goto error;
 111         }
 112         if (pkey->ameth->pub_encode != NULL) {
 113             if (!pkey->ameth->pub_encode(pk, pkey)) {
 114                 ERR_raise(ERR_LIB_X509, X509_R_PUBLIC_KEY_ENCODE_ERROR);
 115                 goto error;
 116             }
 117         } else {
 118             ERR_raise(ERR_LIB_X509, X509_R_METHOD_NOT_SUPPORTED);
 119             goto error;
 120         }
 121     } else if (evp_pkey_is_provided(pkey)) {
 122         unsigned char *der = NULL;
 123         size_t derlen = 0;
 124         OSSL_ENCODER_CTX *ectx =
 125             OSSL_ENCODER_CTX_new_by_EVP_PKEY(pkey, EVP_PKEY_PUBLIC_KEY,
 126                                              "DER", "SubjectPublicKeyInfo",
 127                                              NULL);
 128
 129         if (OSSL_ENCODER_to_data(ectx, &der, &derlen)) {
 130             const unsigned char *pder = der;
 131
 132             pk = d2i_X509_PUBKEY(NULL, &pder, (long)derlen);
 133         }
 134
 135         OSSL_ENCODER_CTX_free(ectx);
 136         OPENSSL_free(der);
 137     }
 138
 139     if (pk == NULL) {
 140         ERR_raise(ERR_LIB_X509, X509_R_UNSUPPORTED_ALGORITHM);
 141         goto error;
 142     }
 143
 144     X509_PUBKEY_free(*x);
 145     if (!EVP_PKEY_up_ref(pkey)) {
 146         ERR_raise(ERR_LIB_X509, ERR_R_INTERNAL_ERROR);
 147         goto error;
 148     }
 149     *x = pk;
 150
 151     /*
 152      * pk->pkey is NULL when using the legacy routine, but is non-NULL when
 153      * going through the encoder, and for all intents and purposes, it's
 154      * a perfect copy of |pkey|, just not the same instance.  In that case,
 155      * we could simply return early, right here.
 156      * However, in the interest of being cautious leaning on paranoia, some
 157      * application might very well depend on the passed |pkey| being used
 158      * and none other, so we spend a few more cycles throwing away the newly
 159      * created |pk->pkey| and replace it with |pkey|.
 160      * TODO(3.0) Investigate if it's safe to change to simply return here
 161      * if |pk->pkey != NULL|.
 162      */
 163     if (pk->pkey != NULL)
 164         EVP_PKEY_free(pk->pkey);
 165
 166     pk->pkey = pkey;
 167     return 1;
 168
 169  error:
 170     X509_PUBKEY_free(pk);
 171     return 0;
 172 }
 173
 174 /*
 175  * Attempt to decode a public key.
 176  * Returns 1 on success, 0 for a decode failure and -1 for a fatal
 177  * error e.g. malloc failure.
 178  */
 179
 180
 181 static int x509_pubkey_decode(EVP_PKEY **ppkey, const X509_PUBKEY *key)
 182 {
 183     EVP_PKEY *pkey = EVP_PKEY_new();
 184
 185     if (pkey == NULL) {
 186         ERR_raise(ERR_LIB_X509, ERR_R_MALLOC_FAILURE);
 187         return -1;
 188     }
 189
 190     if (!EVP_PKEY_set_type(pkey, OBJ_obj2nid(key->algor->algorithm))) {
 191         ERR_raise(ERR_LIB_X509, X509_R_UNSUPPORTED_ALGORITHM);
 192         goto error;
 193     }
 194
 195     if (pkey->ameth->pub_decode) {
 196         /*
 197          * Treat any failure of pub_decode as a decode error. In
 198          * future we could have different return codes for decode
 199          * errors and fatal errors such as malloc failure.
 200          */
 201         if (!pkey->ameth->pub_decode(pkey, key))
 202             goto error;
 203     } else {
 204         ERR_raise(ERR_LIB_X509, X509_R_METHOD_NOT_SUPPORTED);
 205         goto error;
 206     }
 207
 208     *ppkey = pkey;
 209     return 1;
 210
 211  error:
 212     EVP_PKEY_free(pkey);
 213     return 0;
 214 }
 215
 216 EVP_PKEY *X509_PUBKEY_get0(const X509_PUBKEY *key)
 217 {
 218     EVP_PKEY *ret = NULL;
 219
 220     if (key == NULL || key->public_key == NULL)
 221         return NULL;
 222
 223     if (key->pkey != NULL)
 224         return key->pkey;
 225
 226     /*
 227      * When the key ASN.1 is initially parsed an attempt is made to
 228      * decode the public key and cache the EVP_PKEY structure. If this
 229      * operation fails the cached value will be NULL. Parsing continues
 230      * to allow parsing of unknown key types or unsupported forms.
 231      * We repeat the decode operation so the appropriate errors are left
 232      * in the queue.
 233      */
 234     x509_pubkey_decode(&ret, key);
 235     /* If decode doesn't fail something bad happened */
 236     if (ret != NULL) {
 237         ERR_raise(ERR_LIB_X509, ERR_R_INTERNAL_ERROR);
 238         EVP_PKEY_free(ret);
 239     }
 240
 241     return NULL;
 242 }
 243
 244 EVP_PKEY *X509_PUBKEY_get(const X509_PUBKEY *key)
 245 {
 246     EVP_PKEY *ret = X509_PUBKEY_get0(key);
 247
 248     if (ret != NULL && !EVP_PKEY_up_ref(ret)) {
 249         ERR_raise(ERR_LIB_X509, ERR_R_INTERNAL_ERROR);
 250         ret = NULL;
 251     }
 252     return ret;
 253 }
 254
 255 /*
 256  * Now three pseudo ASN1 routines that take an EVP_PKEY structure and encode
 257  * or decode as X509_PUBKEY
 258  */
 259
 260 EVP_PKEY *d2i_PUBKEY_ex(EVP_PKEY **a, const unsigned char **pp, long length,
 261                         OSSL_LIB_CTX *libctx, const char *propq)
 262 {
 263     X509_PUBKEY *xpk, *xpk2 = NULL, **pxpk = NULL;
 264     EVP_PKEY *pktmp = NULL;
 265     const unsigned char *q;
 266
 267     q = *pp;
 268
 269     /*
 270      * If libctx or propq are non-NULL, we take advantage of the reuse
 271      * feature.  It's not generally recommended, but is safe enough for
 272      * newly created structures.
 273      */
 274     if (libctx != NULL || propq != NULL) {
 275         xpk2 = OPENSSL_zalloc(sizeof(*xpk2));
 276         if (xpk2 == NULL) {
 277             ERR_raise(ERR_LIB_X509, ERR_R_MALLOC_FAILURE);
 278             return NULL;
 279         }
 280         if (!x509_pubkey_set0_libctx(xpk2, libctx, propq))
 281             goto end;
 282         pxpk = &xpk2;
 283     }
 284     xpk = d2i_X509_PUBKEY(pxpk, &q, length);
 285     if (xpk == NULL)
 286         goto end;
 287     pktmp = X509_PUBKEY_get(xpk);
 288     X509_PUBKEY_free(xpk);
 289     xpk2 = NULL;                 /* We know that xpk == xpk2 */
 290     if (pktmp == NULL)
 291         goto end;
 292     *pp = q;
 293     if (a != NULL) {
 294         EVP_PKEY_free(*a);
 295         *a = pktmp;
 296     }
 297  end:
 298     X509_PUBKEY_free(xpk2);
 299     return pktmp;
 300 }
 301
 302 EVP_PKEY *d2i_PUBKEY(EVP_PKEY **a, const unsigned char **pp, long length)
 303 {
 304     return d2i_PUBKEY_ex(a, pp, length, NULL, NULL);
 305 }
 306
 307 int i2d_PUBKEY(const EVP_PKEY *a, unsigned char **pp)
 308 {
 309     int ret = -1;
 310
 311     if (a == NULL)
 312         return 0;
 313     if (a->ameth != NULL) {
 314         X509_PUBKEY *xpk = NULL;
 315
 316         if ((xpk = X509_PUBKEY_new()) == NULL)
 317             return -1;
 318
 319         /* pub_encode() only encode parameters, not the key itself */
 320         if (a->ameth->pub_encode != NULL && a->ameth->pub_encode(xpk, a)) {
 321             xpk->pkey = (EVP_PKEY *)a;
 322             ret = i2d_X509_PUBKEY(xpk, pp);
 323             xpk->pkey = NULL;
 324         }
 325         X509_PUBKEY_free(xpk);
 326     } else if (a->keymgmt != NULL) {
 327         OSSL_ENCODER_CTX *ctx =
 328             OSSL_ENCODER_CTX_new_by_EVP_PKEY(a, EVP_PKEY_PUBLIC_KEY,
 329                                              "DER", "SubjectPublicKeyInfo",
 330                                              NULL);
 331         BIO *out = BIO_new(BIO_s_mem());
 332         BUF_MEM *buf = NULL;
 333
 334         if (OSSL_ENCODER_CTX_get_num_encoders(ctx) != 0
 335             && out != NULL
 336             && OSSL_ENCODER_to_bio(ctx, out)
 337             && BIO_get_mem_ptr(out, &buf) > 0) {
 338             ret = buf->length;
 339
 340             if (pp != NULL) {
 341                 if (*pp == NULL) {
 342                     *pp = (unsigned char *)buf->data;
 343                     buf->length = 0;
 344                     buf->data = NULL;
 345                 } else {
 346                     memcpy(*pp, buf->data, ret);
 347                     *pp += ret;
 348                 }
 349             }
 350         }
 351         BIO_free(out);
 352         OSSL_ENCODER_CTX_free(ctx);
 353     }
 354
 355     return ret;
 356 }
 357
 358 /*
 359  * The following are equivalents but which return RSA and DSA keys
 360  */
 361 RSA *d2i_RSA_PUBKEY(RSA **a, const unsigned char **pp, long length)
 362 {
 363     EVP_PKEY *pkey;
 364     RSA *key;
 365     const unsigned char *q;
 366
 367     q = *pp;
 368     pkey = d2i_PUBKEY(NULL, &q, length);
 369     if (pkey == NULL)
 370         return NULL;
 371     key = EVP_PKEY_get1_RSA(pkey);
 372     EVP_PKEY_free(pkey);
 373     if (key == NULL)
 374         return NULL;
 375     *pp = q;
 376     if (a != NULL) {
 377         RSA_free(*a);
 378         *a = key;
 379     }
 380     return key;
 381 }
 382
 383 int i2d_RSA_PUBKEY(const RSA *a, unsigned char **pp)
 384 {
 385     EVP_PKEY *pktmp;
 386     int ret;
 387     if (!a)
 388         return 0;
 389     pktmp = EVP_PKEY_new();
 390     if (pktmp == NULL) {
 391         ERR_raise(ERR_LIB_ASN1, ERR_R_MALLOC_FAILURE);
 392         return -1;
 393     }
 394     (void)EVP_PKEY_assign_RSA(pktmp, (RSA *)a);
 395     ret = i2d_PUBKEY(pktmp, pp);
 396     pktmp->pkey.ptr = NULL;
 397     EVP_PKEY_free(pktmp);
 398     return ret;
 399 }
 400
 401 #ifndef OPENSSL_NO_DSA
 402 DSA *d2i_DSA_PUBKEY(DSA **a, const unsigned char **pp, long length)
 403 {
 404     EVP_PKEY *pkey;
 405     DSA *key;
 406     const unsigned char *q;
 407
 408     q = *pp;
 409     pkey = d2i_PUBKEY(NULL, &q, length);
 410     if (pkey == NULL)
 411         return NULL;
 412     key = EVP_PKEY_get1_DSA(pkey);
 413     EVP_PKEY_free(pkey);
 414     if (key == NULL)
 415         return NULL;
 416     *pp = q;
 417     if (a != NULL) {
 418         DSA_free(*a);
 419         *a = key;
 420     }
 421     return key;
 422 }
 423
 424 int i2d_DSA_PUBKEY(const DSA *a, unsigned char **pp)
 425 {
 426     EVP_PKEY *pktmp;
 427     int ret;
 428     if (!a)
 429         return 0;
 430     pktmp = EVP_PKEY_new();
 431     if (pktmp == NULL) {
 432         ERR_raise(ERR_LIB_ASN1, ERR_R_MALLOC_FAILURE);
 433         return -1;
 434     }
 435     (void)EVP_PKEY_assign_DSA(pktmp, (DSA *)a);
 436     ret = i2d_PUBKEY(pktmp, pp);
 437     pktmp->pkey.ptr = NULL;
 438     EVP_PKEY_free(pktmp);
 439     return ret;
 440 }
 441 #endif
 442
 443 #ifndef OPENSSL_NO_EC
 444 EC_KEY *d2i_EC_PUBKEY(EC_KEY **a, const unsigned char **pp, long length)
 445 {
 446     EVP_PKEY *pkey;
 447     EC_KEY *key;
 448     const unsigned char *q;
 449
 450     q = *pp;
 451     pkey = d2i_PUBKEY(NULL, &q, length);
 452     if (pkey == NULL)
 453         return NULL;
 454     key = EVP_PKEY_get1_EC_KEY(pkey);
 455     EVP_PKEY_free(pkey);
 456     if (key == NULL)
 457         return NULL;
 458     *pp = q;
 459     if (a != NULL) {
 460         EC_KEY_free(*a);
 461         *a = key;
 462     }
 463     return key;
 464 }
 465
 466 int i2d_EC_PUBKEY(const EC_KEY *a, unsigned char **pp)
 467 {
 468     EVP_PKEY *pktmp;
 469     int ret;
 470
 471     if (a == NULL)
 472         return 0;
 473     if ((pktmp = EVP_PKEY_new()) == NULL) {
 474         ERR_raise(ERR_LIB_ASN1, ERR_R_MALLOC_FAILURE);
 475         return -1;
 476     }
 477     (void)EVP_PKEY_assign_EC_KEY(pktmp, (EC_KEY *)a);
 478     ret = i2d_PUBKEY(pktmp, pp);
 479     pktmp->pkey.ptr = NULL;
 480     EVP_PKEY_free(pktmp);
 481     return ret;
 482 }
 483 #endif
 484
 485 int X509_PUBKEY_set0_param(X509_PUBKEY *pub, ASN1_OBJECT *aobj,
 486                            int ptype, void *pval,
 487                            unsigned char *penc, int penclen)
 488 {
 489     if (!X509_ALGOR_set0(pub->algor, aobj, ptype, pval))
 490         return 0;
 491     if (penc) {
 492         OPENSSL_free(pub->public_key->data);
 493         pub->public_key->data = penc;
 494         pub->public_key->length = penclen;
 495         /* Set number of unused bits to zero */
 496         pub->public_key->flags &= ~(ASN1_STRING_FLAG_BITS_LEFT | 0x07);
 497         pub->public_key->flags |= ASN1_STRING_FLAG_BITS_LEFT;
 498     }
 499     return 1;
 500 }
 501
 502 int X509_PUBKEY_get0_param(ASN1_OBJECT **ppkalg,
 503                            const unsigned char **pk, int *ppklen,
 504                            X509_ALGOR **pa, const X509_PUBKEY *pub)
 505 {
 506     if (ppkalg)
 507         *ppkalg = pub->algor->algorithm;
 508     if (pk) {
 509         *pk = pub->public_key->data;
 510         *ppklen = pub->public_key->length;
 511     }
 512     if (pa)
 513         *pa = pub->algor;
 514     return 1;
 515 }
 516
 517 ASN1_BIT_STRING *X509_get0_pubkey_bitstr(const X509 *x)
 518 {
 519     if (x == NULL)
 520         return NULL;
 521     return x->cert_info.key->public_key;
 522 }
 523
 524 /* Returns 1 for equal, 0, for non-equal, < 0 on error */
 525 int X509_PUBKEY_eq(const X509_PUBKEY *a, const X509_PUBKEY *b)
 526 {
 527     X509_ALGOR *algA, *algB;
 528     EVP_PKEY *pA, *pB;
 529
 530     if (a == b)
 531         return 1;
 532     if (a == NULL || b == NULL)
 533         return 0;
 534     if (!X509_PUBKEY_get0_param(NULL, NULL, NULL, &algA, a) || algA == NULL
 535         || !X509_PUBKEY_get0_param(NULL, NULL, NULL, &algB, b) || algB == NULL)
 536         return -2;
 537     if (X509_ALGOR_cmp(algA, algB) != 0)
 538         return 0;
 539     if ((pA = X509_PUBKEY_get0(a)) == NULL
 540         || (pB = X509_PUBKEY_get0(b)) == NULL)
 541         return -2;
 542     return EVP_PKEY_eq(pA, pB);
 543 }
 544
 545 int X509_PUBKEY_get0_libctx(OSSL_LIB_CTX **plibctx, const char **ppropq,
 546                             const X509_PUBKEY *key)
 547 {
 548     if (plibctx)
 549         *plibctx = key->libctx;
 550     if (ppropq)
 551         *ppropq = key->propq;
 552     return 1;
 553 }