crypto/x509/x_pubkey.c

   1 /*
   2  * Copyright 1995-2018 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/serializer.h>
  26
  27 struct X509_pubkey_st {
  28     X509_ALGOR *algor;
  29     ASN1_BIT_STRING *public_key;
  30     EVP_PKEY *pkey;
  31 };
  32
  33 static int x509_pubkey_decode(EVP_PKEY **pk, X509_PUBKEY *key);
  34
  35 /* Minor tweak to operation: free up EVP_PKEY */
  36 static int pubkey_cb(int operation, ASN1_VALUE **pval, const ASN1_ITEM *it,
  37                      void *exarg)
  38 {
  39     if (operation == ASN1_OP_FREE_POST) {
  40         X509_PUBKEY *pubkey = (X509_PUBKEY *)*pval;
  41         EVP_PKEY_free(pubkey->pkey);
  42     } else if (operation == ASN1_OP_D2I_POST) {
  43         /* Attempt to decode public key and cache in pubkey structure. */
  44         X509_PUBKEY *pubkey = (X509_PUBKEY *)*pval;
  45         EVP_PKEY_free(pubkey->pkey);
  46         pubkey->pkey = NULL;
  47         /*
  48          * Opportunistically decode the key but remove any non fatal errors
  49          * from the queue. Subsequent explicit attempts to decode/use the key
  50          * will return an appropriate error.
  51          */
  52         ERR_set_mark();
  53         if (x509_pubkey_decode(&pubkey->pkey, pubkey) == -1)
  54             return 0;
  55         ERR_pop_to_mark();
  56     }
  57     return 1;
  58 }
  59
  60 ASN1_SEQUENCE_cb(X509_PUBKEY, pubkey_cb) = {
  61         ASN1_SIMPLE(X509_PUBKEY, algor, X509_ALGOR),
  62         ASN1_SIMPLE(X509_PUBKEY, public_key, ASN1_BIT_STRING)
  63 } ASN1_SEQUENCE_END_cb(X509_PUBKEY, X509_PUBKEY)
  64
  65 IMPLEMENT_ASN1_FUNCTIONS(X509_PUBKEY)
  66 IMPLEMENT_ASN1_DUP_FUNCTION(X509_PUBKEY)
  67
  68 /* TODO should better be called X509_PUBKEY_set1 */
  69 int X509_PUBKEY_set(X509_PUBKEY **x, EVP_PKEY *pkey)
  70 {
  71     X509_PUBKEY *pk = NULL;
  72
  73     if (x == NULL)
  74         return 0;
  75
  76     if (pkey == NULL)
  77         goto unsupported;
  78
  79     if (pkey->ameth != NULL) {
  80         if ((pk = X509_PUBKEY_new()) == NULL) {
  81             X509err(X509_F_X509_PUBKEY_SET, ERR_R_MALLOC_FAILURE);
  82             goto error;
  83         }
  84         if (pkey->ameth->pub_encode != NULL) {
  85             if (!pkey->ameth->pub_encode(pk, pkey)) {
  86                 X509err(X509_F_X509_PUBKEY_SET,
  87                         X509_R_PUBLIC_KEY_ENCODE_ERROR);
  88                 goto error;
  89             }
  90         } else {
  91             X509err(X509_F_X509_PUBKEY_SET, X509_R_METHOD_NOT_SUPPORTED);
  92             goto error;
  93         }
  94     } else if (pkey->pkeys[0].keymgmt != NULL) {
  95         BIO *bmem = BIO_new(BIO_s_mem());
  96         const char *serprop = "format=der,type=public";
  97         OSSL_SERIALIZER_CTX *sctx =
  98             OSSL_SERIALIZER_CTX_new_by_EVP_PKEY(pkey, serprop);
  99
 100         if (OSSL_SERIALIZER_to_bio(sctx, bmem)) {
 101             const unsigned char *der = NULL;
 102             long derlen = BIO_get_mem_data(bmem, (char **)&der);
 103
 104             pk = d2i_X509_PUBKEY(NULL, &der, derlen);
 105         }
 106
 107         OSSL_SERIALIZER_CTX_free(sctx);
 108         BIO_free(bmem);
 109     }
 110
 111     if (pk == NULL)
 112         goto unsupported;
 113
 114     X509_PUBKEY_free(*x);
 115     if (!EVP_PKEY_up_ref(pkey)) {
 116         X509err(X509_F_X509_PUBKEY_SET, ERR_R_INTERNAL_ERROR);
 117         goto error;
 118     }
 119     *x = pk;
 120
 121     /*
 122      * pk->pkey is NULL when using the legacy routine, but is non-NULL when
 123      * going through the serializer, and for all intents and purposes, it's
 124      * a perfect copy of |pkey|, just not the same instance.  In that case,
 125      * we could simply return early, right here.
 126      * However, in the interest of being cautious leaning on paranoia, some
 127      * application might very well depend on the passed |pkey| being used
 128      * and none other, so we spend a few more cycles throwing away the newly
 129      * created |pk->pkey| and replace it with |pkey|.
 130      * TODO(3.0) Investigate if it's safe to change to simply return here
 131      * if |pk->pkey != NULL|.
 132      */
 133     if (pk->pkey != NULL)
 134         EVP_PKEY_free(pk->pkey);
 135
 136     pk->pkey = pkey;
 137     return 1;
 138
 139  unsupported:
 140     X509err(X509_F_X509_PUBKEY_SET, X509_R_UNSUPPORTED_ALGORITHM);
 141
 142  error:
 143     X509_PUBKEY_free(pk);
 144     return 0;
 145 }
 146
 147 /*
 148  * Attempt to decode a public key.
 149  * Returns 1 on success, 0 for a decode failure and -1 for a fatal
 150  * error e.g. malloc failure.
 151  */
 152
 153
 154 static int x509_pubkey_decode(EVP_PKEY **ppkey, X509_PUBKEY *key)
 155 {
 156     EVP_PKEY *pkey = EVP_PKEY_new();
 157
 158     if (pkey == NULL) {
 159         X509err(X509_F_X509_PUBKEY_DECODE, ERR_R_MALLOC_FAILURE);
 160         return -1;
 161     }
 162
 163     if (!EVP_PKEY_set_type(pkey, OBJ_obj2nid(key->algor->algorithm))) {
 164         X509err(X509_F_X509_PUBKEY_DECODE, X509_R_UNSUPPORTED_ALGORITHM);
 165         goto error;
 166     }
 167
 168     if (pkey->ameth->pub_decode) {
 169         /*
 170          * Treat any failure of pub_decode as a decode error. In
 171          * future we could have different return codes for decode
 172          * errors and fatal errors such as malloc failure.
 173          */
 174         if (!pkey->ameth->pub_decode(pkey, key)) {
 175             X509err(X509_F_X509_PUBKEY_DECODE, X509_R_PUBLIC_KEY_DECODE_ERROR);
 176             goto error;
 177         }
 178     } else {
 179         X509err(X509_F_X509_PUBKEY_DECODE, X509_R_METHOD_NOT_SUPPORTED);
 180         goto error;
 181     }
 182
 183     *ppkey = pkey;
 184     return 1;
 185
 186  error:
 187     EVP_PKEY_free(pkey);
 188     return 0;
 189 }
 190
 191 EVP_PKEY *X509_PUBKEY_get0(X509_PUBKEY *key)
 192 {
 193     EVP_PKEY *ret = NULL;
 194
 195     if (key == NULL || key->public_key == NULL)
 196         return NULL;
 197
 198     if (key->pkey != NULL)
 199         return key->pkey;
 200
 201     /*
 202      * When the key ASN.1 is initially parsed an attempt is made to
 203      * decode the public key and cache the EVP_PKEY structure. If this
 204      * operation fails the cached value will be NULL. Parsing continues
 205      * to allow parsing of unknown key types or unsupported forms.
 206      * We repeat the decode operation so the appropriate errors are left
 207      * in the queue.
 208      */
 209     x509_pubkey_decode(&ret, key);
 210     /* If decode doesn't fail something bad happened */
 211     if (ret != NULL) {
 212         X509err(X509_F_X509_PUBKEY_GET0, ERR_R_INTERNAL_ERROR);
 213         EVP_PKEY_free(ret);
 214     }
 215
 216     return NULL;
 217 }
 218
 219 EVP_PKEY *X509_PUBKEY_get(X509_PUBKEY *key)
 220 {
 221     EVP_PKEY *ret = X509_PUBKEY_get0(key);
 222     if (ret != NULL)
 223         EVP_PKEY_up_ref(ret);
 224     return ret;
 225 }
 226
 227 /*
 228  * Now two pseudo ASN1 routines that take an EVP_PKEY structure and encode or
 229  * decode as X509_PUBKEY
 230  */
 231
 232 EVP_PKEY *d2i_PUBKEY(EVP_PKEY **a, const unsigned char **pp, long length)
 233 {
 234     X509_PUBKEY *xpk;
 235     EVP_PKEY *pktmp;
 236     const unsigned char *q;
 237
 238     q = *pp;
 239     xpk = d2i_X509_PUBKEY(NULL, &q, length);
 240     if (xpk == NULL)
 241         return NULL;
 242     pktmp = X509_PUBKEY_get(xpk);
 243     X509_PUBKEY_free(xpk);
 244     if (pktmp == NULL)
 245         return NULL;
 246     *pp = q;
 247     if (a != NULL) {
 248         EVP_PKEY_free(*a);
 249         *a = pktmp;
 250     }
 251     return pktmp;
 252 }
 253
 254 int i2d_PUBKEY(const EVP_PKEY *a, unsigned char **pp)
 255 {
 256     X509_PUBKEY *xpk = NULL;
 257     int ret = -1;
 258
 259     if (a == NULL)
 260         return 0;
 261     if ((xpk = X509_PUBKEY_new()) == NULL)
 262         return -1;
 263     if (a->ameth != NULL && a->ameth->pub_encode != NULL
 264         && !a->ameth->pub_encode(xpk, a))
 265         goto error;
 266     xpk->pkey = (EVP_PKEY *)a;
 267     ret = i2d_X509_PUBKEY(xpk, pp);
 268     xpk->pkey = NULL;
 269  error:
 270     X509_PUBKEY_free(xpk);
 271     return ret;
 272 }
 273
 274 /*
 275  * The following are equivalents but which return RSA and DSA keys
 276  */
 277 #ifndef OPENSSL_NO_RSA
 278 RSA *d2i_RSA_PUBKEY(RSA **a, const unsigned char **pp, long length)
 279 {
 280     EVP_PKEY *pkey;
 281     RSA *key;
 282     const unsigned char *q;
 283
 284     q = *pp;
 285     pkey = d2i_PUBKEY(NULL, &q, length);
 286     if (pkey == NULL)
 287         return NULL;
 288     key = EVP_PKEY_get1_RSA(pkey);
 289     EVP_PKEY_free(pkey);
 290     if (key == NULL)
 291         return NULL;
 292     *pp = q;
 293     if (a != NULL) {
 294         RSA_free(*a);
 295         *a = key;
 296     }
 297     return key;
 298 }
 299
 300 int i2d_RSA_PUBKEY(const RSA *a, unsigned char **pp)
 301 {
 302     EVP_PKEY *pktmp;
 303     int ret;
 304     if (!a)
 305         return 0;
 306     pktmp = EVP_PKEY_new();
 307     if (pktmp == NULL) {
 308         ASN1err(ASN1_F_I2D_RSA_PUBKEY, ERR_R_MALLOC_FAILURE);
 309         return -1;
 310     }
 311     (void)EVP_PKEY_assign_RSA(pktmp, (RSA *)a);
 312     ret = i2d_PUBKEY(pktmp, pp);
 313     pktmp->pkey.ptr = NULL;
 314     EVP_PKEY_free(pktmp);
 315     return ret;
 316 }
 317 #endif
 318
 319 #ifndef OPENSSL_NO_DSA
 320 DSA *d2i_DSA_PUBKEY(DSA **a, const unsigned char **pp, long length)
 321 {
 322     EVP_PKEY *pkey;
 323     DSA *key;
 324     const unsigned char *q;
 325
 326     q = *pp;
 327     pkey = d2i_PUBKEY(NULL, &q, length);
 328     if (pkey == NULL)
 329         return NULL;
 330     key = EVP_PKEY_get1_DSA(pkey);
 331     EVP_PKEY_free(pkey);
 332     if (key == NULL)
 333         return NULL;
 334     *pp = q;
 335     if (a != NULL) {
 336         DSA_free(*a);
 337         *a = key;
 338     }
 339     return key;
 340 }
 341
 342 int i2d_DSA_PUBKEY(const DSA *a, unsigned char **pp)
 343 {
 344     EVP_PKEY *pktmp;
 345     int ret;
 346     if (!a)
 347         return 0;
 348     pktmp = EVP_PKEY_new();
 349     if (pktmp == NULL) {
 350         ASN1err(ASN1_F_I2D_DSA_PUBKEY, ERR_R_MALLOC_FAILURE);
 351         return -1;
 352     }
 353     (void)EVP_PKEY_assign_DSA(pktmp, (DSA *)a);
 354     ret = i2d_PUBKEY(pktmp, pp);
 355     pktmp->pkey.ptr = NULL;
 356     EVP_PKEY_free(pktmp);
 357     return ret;
 358 }
 359 #endif
 360
 361 #ifndef OPENSSL_NO_EC
 362 EC_KEY *d2i_EC_PUBKEY(EC_KEY **a, const unsigned char **pp, long length)
 363 {
 364     EVP_PKEY *pkey;
 365     EC_KEY *key;
 366     const unsigned char *q;
 367
 368     q = *pp;
 369     pkey = d2i_PUBKEY(NULL, &q, length);
 370     if (pkey == NULL)
 371         return NULL;
 372     key = EVP_PKEY_get1_EC_KEY(pkey);
 373     EVP_PKEY_free(pkey);
 374     if (key == NULL)
 375         return NULL;
 376     *pp = q;
 377     if (a != NULL) {
 378         EC_KEY_free(*a);
 379         *a = key;
 380     }
 381     return key;
 382 }
 383
 384 int i2d_EC_PUBKEY(const EC_KEY *a, unsigned char **pp)
 385 {
 386     EVP_PKEY *pktmp;
 387     int ret;
 388
 389     if (a == NULL)
 390         return 0;
 391     if ((pktmp = EVP_PKEY_new()) == NULL) {
 392         ASN1err(ASN1_F_I2D_EC_PUBKEY, ERR_R_MALLOC_FAILURE);
 393         return -1;
 394     }
 395     (void)EVP_PKEY_assign_EC_KEY(pktmp, (EC_KEY *)a);
 396     ret = i2d_PUBKEY(pktmp, pp);
 397     pktmp->pkey.ptr = NULL;
 398     EVP_PKEY_free(pktmp);
 399     return ret;
 400 }
 401 #endif
 402
 403 int X509_PUBKEY_set0_param(X509_PUBKEY *pub, ASN1_OBJECT *aobj,
 404                            int ptype, void *pval,
 405                            unsigned char *penc, int penclen)
 406 {
 407     if (!X509_ALGOR_set0(pub->algor, aobj, ptype, pval))
 408         return 0;
 409     if (penc) {
 410         OPENSSL_free(pub->public_key->data);
 411         pub->public_key->data = penc;
 412         pub->public_key->length = penclen;
 413         /* Set number of unused bits to zero */
 414         pub->public_key->flags &= ~(ASN1_STRING_FLAG_BITS_LEFT | 0x07);
 415         pub->public_key->flags |= ASN1_STRING_FLAG_BITS_LEFT;
 416     }
 417     return 1;
 418 }
 419
 420 int X509_PUBKEY_get0_param(ASN1_OBJECT **ppkalg,
 421                            const unsigned char **pk, int *ppklen,
 422                            X509_ALGOR **pa, X509_PUBKEY *pub)
 423 {
 424     if (ppkalg)
 425         *ppkalg = pub->algor->algorithm;
 426     if (pk) {
 427         *pk = pub->public_key->data;
 428         *ppklen = pub->public_key->length;
 429     }
 430     if (pa)
 431         *pa = pub->algor;
 432     return 1;
 433 }
 434
 435 ASN1_BIT_STRING *X509_get0_pubkey_bitstr(const X509 *x)
 436 {
 437     if (x == NULL)
 438         return NULL;
 439     return x->cert_info.key->public_key;
 440 }