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 #include <stdio.h>
  11 #include "internal/cryptlib.h"
  12 #include <openssl/asn1t.h>
  13 #include <openssl/x509.h>
  14 #include "crypto/asn1.h"
  15 #include "crypto/evp.h"
  16 #include "crypto/x509.h"
  17 #include <openssl/rsa.h>
  18 #include <openssl/dsa.h>
  19
  20 struct X509_pubkey_st {
  21     X509_ALGOR *algor;
  22     ASN1_BIT_STRING *public_key;
  23     EVP_PKEY *pkey;
  24 };
  25
  26 static int x509_pubkey_decode(EVP_PKEY **pk, X509_PUBKEY *key);
  27
  28 /* Minor tweak to operation: free up EVP_PKEY */
  29 static int pubkey_cb(int operation, ASN1_VALUE **pval, const ASN1_ITEM *it,
  30                      void *exarg)
  31 {
  32     if (operation == ASN1_OP_FREE_POST) {
  33         X509_PUBKEY *pubkey = (X509_PUBKEY *)*pval;
  34         EVP_PKEY_free(pubkey->pkey);
  35     } else if (operation == ASN1_OP_D2I_POST) {
  36         /* Attempt to decode public key and cache in pubkey structure. */
  37         X509_PUBKEY *pubkey = (X509_PUBKEY *)*pval;
  38         EVP_PKEY_free(pubkey->pkey);
  39         pubkey->pkey = NULL;
  40         /*
  41          * Opportunistically decode the key but remove any non fatal errors
  42          * from the queue. Subsequent explicit attempts to decode/use the key
  43          * will return an appropriate error.
  44          */
  45         ERR_set_mark();
  46         if (x509_pubkey_decode(&pubkey->pkey, pubkey) == -1)
  47             return 0;
  48         ERR_pop_to_mark();
  49     }
  50     return 1;
  51 }
  52
  53 ASN1_SEQUENCE_cb(X509_PUBKEY, pubkey_cb) = {
  54         ASN1_SIMPLE(X509_PUBKEY, algor, X509_ALGOR),
  55         ASN1_SIMPLE(X509_PUBKEY, public_key, ASN1_BIT_STRING)
  56 } ASN1_SEQUENCE_END_cb(X509_PUBKEY, X509_PUBKEY)
  57
  58 IMPLEMENT_ASN1_FUNCTIONS(X509_PUBKEY)
  59 IMPLEMENT_ASN1_DUP_FUNCTION(X509_PUBKEY)
  60
  61 /* TODO should better be called X509_PUBKEY_set1 */
  62 int X509_PUBKEY_set(X509_PUBKEY **x, EVP_PKEY *pkey)
  63 {
  64     X509_PUBKEY *pk = NULL;
  65
  66     if (x == NULL)
  67         return 0;
  68
  69     if ((pk = X509_PUBKEY_new()) == NULL)
  70         goto error;
  71
  72     if (pkey != NULL && pkey->ameth) {
  73         if (pkey->ameth->pub_encode) {
  74             if (!pkey->ameth->pub_encode(pk, pkey)) {
  75                 X509err(X509_F_X509_PUBKEY_SET,
  76                         X509_R_PUBLIC_KEY_ENCODE_ERROR);
  77                 goto error;
  78             }
  79         } else {
  80             X509err(X509_F_X509_PUBKEY_SET, X509_R_METHOD_NOT_SUPPORTED);
  81             goto error;
  82         }
  83     } else {
  84         X509err(X509_F_X509_PUBKEY_SET, X509_R_UNSUPPORTED_ALGORITHM);
  85         goto error;
  86     }
  87
  88     X509_PUBKEY_free(*x);
  89     *x = pk;
  90     pk->pkey = pkey;
  91     return EVP_PKEY_up_ref(pkey);
  92
  93  error:
  94     X509_PUBKEY_free(pk);
  95     return 0;
  96 }
  97
  98 /*
  99  * Attempt to decode a public key.
 100  * Returns 1 on success, 0 for a decode failure and -1 for a fatal
 101  * error e.g. malloc failure.
 102  */
 103
 104
 105 static int x509_pubkey_decode(EVP_PKEY **ppkey, X509_PUBKEY *key)
 106 {
 107     EVP_PKEY *pkey = EVP_PKEY_new();
 108
 109     if (pkey == NULL) {
 110         X509err(X509_F_X509_PUBKEY_DECODE, ERR_R_MALLOC_FAILURE);
 111         return -1;
 112     }
 113
 114     if (!EVP_PKEY_set_type(pkey, OBJ_obj2nid(key->algor->algorithm))) {
 115         X509err(X509_F_X509_PUBKEY_DECODE, X509_R_UNSUPPORTED_ALGORITHM);
 116         goto error;
 117     }
 118
 119     if (pkey->ameth->pub_decode) {
 120         /*
 121          * Treat any failure of pub_decode as a decode error. In
 122          * future we could have different return codes for decode
 123          * errors and fatal errors such as malloc failure.
 124          */
 125         if (!pkey->ameth->pub_decode(pkey, key)) {
 126             X509err(X509_F_X509_PUBKEY_DECODE, X509_R_PUBLIC_KEY_DECODE_ERROR);
 127             goto error;
 128         }
 129     } else {
 130         X509err(X509_F_X509_PUBKEY_DECODE, X509_R_METHOD_NOT_SUPPORTED);
 131         goto error;
 132     }
 133
 134     *ppkey = pkey;
 135     return 1;
 136
 137  error:
 138     EVP_PKEY_free(pkey);
 139     return 0;
 140 }
 141
 142 EVP_PKEY *X509_PUBKEY_get0(X509_PUBKEY *key)
 143 {
 144     EVP_PKEY *ret = NULL;
 145
 146     if (key == NULL || key->public_key == NULL)
 147         return NULL;
 148
 149     if (key->pkey != NULL)
 150         return key->pkey;
 151
 152     /*
 153      * When the key ASN.1 is initially parsed an attempt is made to
 154      * decode the public key and cache the EVP_PKEY structure. If this
 155      * operation fails the cached value will be NULL. Parsing continues
 156      * to allow parsing of unknown key types or unsupported forms.
 157      * We repeat the decode operation so the appropriate errors are left
 158      * in the queue.
 159      */
 160     x509_pubkey_decode(&ret, key);
 161     /* If decode doesn't fail something bad happened */
 162     if (ret != NULL) {
 163         X509err(X509_F_X509_PUBKEY_GET0, ERR_R_INTERNAL_ERROR);
 164         EVP_PKEY_free(ret);
 165     }
 166
 167     return NULL;
 168 }
 169
 170 EVP_PKEY *X509_PUBKEY_get(X509_PUBKEY *key)
 171 {
 172     EVP_PKEY *ret = X509_PUBKEY_get0(key);
 173     if (ret != NULL)
 174         EVP_PKEY_up_ref(ret);
 175     return ret;
 176 }
 177
 178 /*
 179  * Now two pseudo ASN1 routines that take an EVP_PKEY structure and encode or
 180  * decode as X509_PUBKEY
 181  */
 182
 183 EVP_PKEY *d2i_PUBKEY(EVP_PKEY **a, const unsigned char **pp, long length)
 184 {
 185     X509_PUBKEY *xpk;
 186     EVP_PKEY *pktmp;
 187     const unsigned char *q;
 188
 189     q = *pp;
 190     xpk = d2i_X509_PUBKEY(NULL, &q, length);
 191     if (xpk == NULL)
 192         return NULL;
 193     pktmp = X509_PUBKEY_get(xpk);
 194     X509_PUBKEY_free(xpk);
 195     if (pktmp == NULL)
 196         return NULL;
 197     *pp = q;
 198     if (a != NULL) {
 199         EVP_PKEY_free(*a);
 200         *a = pktmp;
 201     }
 202     return pktmp;
 203 }
 204
 205 int i2d_PUBKEY(const EVP_PKEY *a, unsigned char **pp)
 206 {
 207     X509_PUBKEY *xpk = NULL;
 208     int ret = -1;
 209
 210     if (a == NULL)
 211         return 0;
 212     if ((xpk = X509_PUBKEY_new()) == NULL)
 213         return -1;
 214     if (a->ameth != NULL && a->ameth->pub_encode != NULL
 215         && !a->ameth->pub_encode(xpk, a))
 216         goto error;
 217     xpk->pkey = (EVP_PKEY *)a;
 218     ret = i2d_X509_PUBKEY(xpk, pp);
 219     xpk->pkey = NULL;
 220  error:
 221     X509_PUBKEY_free(xpk);
 222     return ret;
 223 }
 224
 225 /*
 226  * The following are equivalents but which return RSA and DSA keys
 227  */
 228 #ifndef OPENSSL_NO_RSA
 229 RSA *d2i_RSA_PUBKEY(RSA **a, const unsigned char **pp, long length)
 230 {
 231     EVP_PKEY *pkey;
 232     RSA *key;
 233     const unsigned char *q;
 234
 235     q = *pp;
 236     pkey = d2i_PUBKEY(NULL, &q, length);
 237     if (pkey == NULL)
 238         return NULL;
 239     key = EVP_PKEY_get1_RSA(pkey);
 240     EVP_PKEY_free(pkey);
 241     if (key == NULL)
 242         return NULL;
 243     *pp = q;
 244     if (a != NULL) {
 245         RSA_free(*a);
 246         *a = key;
 247     }
 248     return key;
 249 }
 250
 251 int i2d_RSA_PUBKEY(const RSA *a, unsigned char **pp)
 252 {
 253     EVP_PKEY *pktmp;
 254     int ret;
 255     if (!a)
 256         return 0;
 257     pktmp = EVP_PKEY_new();
 258     if (pktmp == NULL) {
 259         ASN1err(ASN1_F_I2D_RSA_PUBKEY, ERR_R_MALLOC_FAILURE);
 260         return -1;
 261     }
 262     (void)EVP_PKEY_assign_RSA(pktmp, (RSA *)a);
 263     ret = i2d_PUBKEY(pktmp, pp);
 264     pktmp->pkey.ptr = NULL;
 265     EVP_PKEY_free(pktmp);
 266     return ret;
 267 }
 268 #endif
 269
 270 #ifndef OPENSSL_NO_DSA
 271 DSA *d2i_DSA_PUBKEY(DSA **a, const unsigned char **pp, long length)
 272 {
 273     EVP_PKEY *pkey;
 274     DSA *key;
 275     const unsigned char *q;
 276
 277     q = *pp;
 278     pkey = d2i_PUBKEY(NULL, &q, length);
 279     if (pkey == NULL)
 280         return NULL;
 281     key = EVP_PKEY_get1_DSA(pkey);
 282     EVP_PKEY_free(pkey);
 283     if (key == NULL)
 284         return NULL;
 285     *pp = q;
 286     if (a != NULL) {
 287         DSA_free(*a);
 288         *a = key;
 289     }
 290     return key;
 291 }
 292
 293 int i2d_DSA_PUBKEY(const DSA *a, unsigned char **pp)
 294 {
 295     EVP_PKEY *pktmp;
 296     int ret;
 297     if (!a)
 298         return 0;
 299     pktmp = EVP_PKEY_new();
 300     if (pktmp == NULL) {
 301         ASN1err(ASN1_F_I2D_DSA_PUBKEY, ERR_R_MALLOC_FAILURE);
 302         return -1;
 303     }
 304     (void)EVP_PKEY_assign_DSA(pktmp, (DSA *)a);
 305     ret = i2d_PUBKEY(pktmp, pp);
 306     pktmp->pkey.ptr = NULL;
 307     EVP_PKEY_free(pktmp);
 308     return ret;
 309 }
 310 #endif
 311
 312 #ifndef OPENSSL_NO_EC
 313 EC_KEY *d2i_EC_PUBKEY(EC_KEY **a, const unsigned char **pp, long length)
 314 {
 315     EVP_PKEY *pkey;
 316     EC_KEY *key;
 317     const unsigned char *q;
 318
 319     q = *pp;
 320     pkey = d2i_PUBKEY(NULL, &q, length);
 321     if (pkey == NULL)
 322         return NULL;
 323     key = EVP_PKEY_get1_EC_KEY(pkey);
 324     EVP_PKEY_free(pkey);
 325     if (key == NULL)
 326         return NULL;
 327     *pp = q;
 328     if (a != NULL) {
 329         EC_KEY_free(*a);
 330         *a = key;
 331     }
 332     return key;
 333 }
 334
 335 int i2d_EC_PUBKEY(const EC_KEY *a, unsigned char **pp)
 336 {
 337     EVP_PKEY *pktmp;
 338     int ret;
 339
 340     if (a == NULL)
 341         return 0;
 342     if ((pktmp = EVP_PKEY_new()) == NULL) {
 343         ASN1err(ASN1_F_I2D_EC_PUBKEY, ERR_R_MALLOC_FAILURE);
 344         return -1;
 345     }
 346     (void)EVP_PKEY_assign_EC_KEY(pktmp, (EC_KEY *)a);
 347     ret = i2d_PUBKEY(pktmp, pp);
 348     pktmp->pkey.ptr = NULL;
 349     EVP_PKEY_free(pktmp);
 350     return ret;
 351 }
 352 #endif
 353
 354 int X509_PUBKEY_set0_param(X509_PUBKEY *pub, ASN1_OBJECT *aobj,
 355                            int ptype, void *pval,
 356                            unsigned char *penc, int penclen)
 357 {
 358     if (!X509_ALGOR_set0(pub->algor, aobj, ptype, pval))
 359         return 0;
 360     if (penc) {
 361         OPENSSL_free(pub->public_key->data);
 362         pub->public_key->data = penc;
 363         pub->public_key->length = penclen;
 364         /* Set number of unused bits to zero */
 365         pub->public_key->flags &= ~(ASN1_STRING_FLAG_BITS_LEFT | 0x07);
 366         pub->public_key->flags |= ASN1_STRING_FLAG_BITS_LEFT;
 367     }
 368     return 1;
 369 }
 370
 371 int X509_PUBKEY_get0_param(ASN1_OBJECT **ppkalg,
 372                            const unsigned char **pk, int *ppklen,
 373                            X509_ALGOR **pa, X509_PUBKEY *pub)
 374 {
 375     if (ppkalg)
 376         *ppkalg = pub->algor->algorithm;
 377     if (pk) {
 378         *pk = pub->public_key->data;
 379         *ppklen = pub->public_key->length;
 380     }
 381     if (pa)
 382         *pa = pub->algor;
 383     return 1;
 384 }
 385
 386 ASN1_BIT_STRING *X509_get0_pubkey_bitstr(const X509 *x)
 387 {
 388     if (x == NULL)
 389         return NULL;
 390     return x->cert_info.key->public_key;
 391 }