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 "internal/asn1_int.h"
  15 #include "internal/evp_int.h"
  16 #include "internal/x509_int.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
  60 int X509_PUBKEY_set(X509_PUBKEY **x, EVP_PKEY *pkey)
  61 {
  62     X509_PUBKEY *pk = NULL;
  63
  64     if (x == NULL)
  65         return 0;
  66
  67     if ((pk = X509_PUBKEY_new()) == NULL)
  68         goto error;
  69
  70     if (pkey->ameth) {
  71         if (pkey->ameth->pub_encode) {
  72             if (!pkey->ameth->pub_encode(pk, pkey)) {
  73                 X509err(X509_F_X509_PUBKEY_SET,
  74                         X509_R_PUBLIC_KEY_ENCODE_ERROR);
  75                 goto error;
  76             }
  77         } else {
  78             X509err(X509_F_X509_PUBKEY_SET, X509_R_METHOD_NOT_SUPPORTED);
  79             goto error;
  80         }
  81     } else {
  82         X509err(X509_F_X509_PUBKEY_SET, X509_R_UNSUPPORTED_ALGORITHM);
  83         goto error;
  84     }
  85
  86     X509_PUBKEY_free(*x);
  87     *x = pk;
  88     pk->pkey = pkey;
  89     EVP_PKEY_up_ref(pkey);
  90     return 1;
  91
  92  error:
  93     X509_PUBKEY_free(pk);
  94     return 0;
  95 }
  96
  97 /*
  98  * Attempt to decode a public key.
  99  * Returns 1 on success, 0 for a decode failure and -1 for a fatal
 100  * error e.g. malloc failure.
 101  */
 102
 103
 104 static int x509_pubkey_decode(EVP_PKEY **ppkey, X509_PUBKEY *key)
 105 {
 106     EVP_PKEY *pkey = EVP_PKEY_new();
 107
 108     if (pkey == NULL) {
 109         X509err(X509_F_X509_PUBKEY_DECODE, ERR_R_MALLOC_FAILURE);
 110         return -1;
 111     }
 112
 113     if (!EVP_PKEY_set_type(pkey, OBJ_obj2nid(key->algor->algorithm))) {
 114         X509err(X509_F_X509_PUBKEY_DECODE, X509_R_UNSUPPORTED_ALGORITHM);
 115         goto error;
 116     }
 117
 118     if (pkey->ameth->pub_decode) {
 119         /*
 120          * Treat any failure of pub_decode as a decode error. In
 121          * future we could have different return codes for decode
 122          * errors and fatal errors such as malloc failure.
 123          */
 124         if (!pkey->ameth->pub_decode(pkey, key)) {
 125             X509err(X509_F_X509_PUBKEY_DECODE, X509_R_PUBLIC_KEY_DECODE_ERROR);
 126             goto error;
 127         }
 128     } else {
 129         X509err(X509_F_X509_PUBKEY_DECODE, X509_R_METHOD_NOT_SUPPORTED);
 130         goto error;
 131     }
 132
 133     *ppkey = pkey;
 134     return 1;
 135
 136  error:
 137     EVP_PKEY_free(pkey);
 138     return 0;
 139 }
 140
 141 EVP_PKEY *X509_PUBKEY_get0(X509_PUBKEY *key)
 142 {
 143     EVP_PKEY *ret = NULL;
 144
 145     if (key == NULL || key->public_key == NULL)
 146         return NULL;
 147
 148     if (key->pkey != NULL)
 149         return key->pkey;
 150
 151     /*
 152      * When the key ASN.1 is initially parsed an attempt is made to
 153      * decode the public key and cache the EVP_PKEY structure. If this
 154      * operation fails the cached value will be NULL. Parsing continues
 155      * to allow parsing of unknown key types or unsupported forms.
 156      * We repeat the decode operation so the appropriate errors are left
 157      * in the queue.
 158      */
 159     x509_pubkey_decode(&ret, key);
 160     /* If decode doesn't fail something bad happened */
 161     if (ret != NULL) {
 162         X509err(X509_F_X509_PUBKEY_GET0, ERR_R_INTERNAL_ERROR);
 163         EVP_PKEY_free(ret);
 164     }
 165
 166     return NULL;
 167 }
 168
 169 EVP_PKEY *X509_PUBKEY_get(X509_PUBKEY *key)
 170 {
 171     EVP_PKEY *ret = X509_PUBKEY_get0(key);
 172     if (ret != NULL)
 173         EVP_PKEY_up_ref(ret);
 174     return ret;
 175 }
 176
 177 /*
 178  * Now two pseudo ASN1 routines that take an EVP_PKEY structure and encode or
 179  * decode as X509_PUBKEY
 180  */
 181
 182 EVP_PKEY *d2i_PUBKEY(EVP_PKEY **a, const unsigned char **pp, long length)
 183 {
 184     X509_PUBKEY *xpk;
 185     EVP_PKEY *pktmp;
 186     const unsigned char *q;
 187     q = *pp;
 188     xpk = d2i_X509_PUBKEY(NULL, &q, length);
 189     if (!xpk)
 190         return NULL;
 191     pktmp = X509_PUBKEY_get(xpk);
 192     X509_PUBKEY_free(xpk);
 193     if (!pktmp)
 194         return NULL;
 195     *pp = q;
 196     if (a) {
 197         EVP_PKEY_free(*a);
 198         *a = pktmp;
 199     }
 200     return pktmp;
 201 }
 202
 203 int i2d_PUBKEY(EVP_PKEY *a, unsigned char **pp)
 204 {
 205     X509_PUBKEY *xpk = NULL;
 206     int ret;
 207     if (!a)
 208         return 0;
 209     if (!X509_PUBKEY_set(&xpk, a))
 210         return -1;
 211     ret = i2d_X509_PUBKEY(xpk, pp);
 212     X509_PUBKEY_free(xpk);
 213     return ret;
 214 }
 215
 216 /*
 217  * The following are equivalents but which return RSA and DSA keys
 218  */
 219 #ifndef OPENSSL_NO_RSA
 220 RSA *d2i_RSA_PUBKEY(RSA **a, const unsigned char **pp, long length)
 221 {
 222     EVP_PKEY *pkey;
 223     RSA *key;
 224     const unsigned char *q;
 225     q = *pp;
 226     pkey = d2i_PUBKEY(NULL, &q, length);
 227     if (!pkey)
 228         return NULL;
 229     key = EVP_PKEY_get1_RSA(pkey);
 230     EVP_PKEY_free(pkey);
 231     if (!key)
 232         return NULL;
 233     *pp = q;
 234     if (a) {
 235         RSA_free(*a);
 236         *a = key;
 237     }
 238     return key;
 239 }
 240
 241 int i2d_RSA_PUBKEY(RSA *a, unsigned char **pp)
 242 {
 243     EVP_PKEY *pktmp;
 244     int ret;
 245     if (!a)
 246         return 0;
 247     pktmp = EVP_PKEY_new();
 248     if (pktmp == NULL) {
 249         ASN1err(ASN1_F_I2D_RSA_PUBKEY, ERR_R_MALLOC_FAILURE);
 250         return -1;
 251     }
 252     EVP_PKEY_set1_RSA(pktmp, a);
 253     ret = i2d_PUBKEY(pktmp, pp);
 254     EVP_PKEY_free(pktmp);
 255     return ret;
 256 }
 257 #endif
 258
 259 #ifndef OPENSSL_NO_DSA
 260 DSA *d2i_DSA_PUBKEY(DSA **a, const unsigned char **pp, long length)
 261 {
 262     EVP_PKEY *pkey;
 263     DSA *key;
 264     const unsigned char *q;
 265     q = *pp;
 266     pkey = d2i_PUBKEY(NULL, &q, length);
 267     if (!pkey)
 268         return NULL;
 269     key = EVP_PKEY_get1_DSA(pkey);
 270     EVP_PKEY_free(pkey);
 271     if (!key)
 272         return NULL;
 273     *pp = q;
 274     if (a) {
 275         DSA_free(*a);
 276         *a = key;
 277     }
 278     return key;
 279 }
 280
 281 int i2d_DSA_PUBKEY(DSA *a, unsigned char **pp)
 282 {
 283     EVP_PKEY *pktmp;
 284     int ret;
 285     if (!a)
 286         return 0;
 287     pktmp = EVP_PKEY_new();
 288     if (pktmp == NULL) {
 289         ASN1err(ASN1_F_I2D_DSA_PUBKEY, ERR_R_MALLOC_FAILURE);
 290         return -1;
 291     }
 292     EVP_PKEY_set1_DSA(pktmp, a);
 293     ret = i2d_PUBKEY(pktmp, pp);
 294     EVP_PKEY_free(pktmp);
 295     return ret;
 296 }
 297 #endif
 298
 299 #ifndef OPENSSL_NO_EC
 300 EC_KEY *d2i_EC_PUBKEY(EC_KEY **a, const unsigned char **pp, long length)
 301 {
 302     EVP_PKEY *pkey;
 303     EC_KEY *key;
 304     const unsigned char *q;
 305     q = *pp;
 306     pkey = d2i_PUBKEY(NULL, &q, length);
 307     if (!pkey)
 308         return NULL;
 309     key = EVP_PKEY_get1_EC_KEY(pkey);
 310     EVP_PKEY_free(pkey);
 311     if (!key)
 312         return NULL;
 313     *pp = q;
 314     if (a) {
 315         EC_KEY_free(*a);
 316         *a = key;
 317     }
 318     return key;
 319 }
 320
 321 int i2d_EC_PUBKEY(EC_KEY *a, unsigned char **pp)
 322 {
 323     EVP_PKEY *pktmp;
 324     int ret;
 325     if (!a)
 326         return 0;
 327     if ((pktmp = EVP_PKEY_new()) == NULL) {
 328         ASN1err(ASN1_F_I2D_EC_PUBKEY, ERR_R_MALLOC_FAILURE);
 329         return -1;
 330     }
 331     EVP_PKEY_set1_EC_KEY(pktmp, a);
 332     ret = i2d_PUBKEY(pktmp, pp);
 333     EVP_PKEY_free(pktmp);
 334     return ret;
 335 }
 336 #endif
 337
 338 int X509_PUBKEY_set0_param(X509_PUBKEY *pub, ASN1_OBJECT *aobj,
 339                            int ptype, void *pval,
 340                            unsigned char *penc, int penclen)
 341 {
 342     if (!X509_ALGOR_set0(pub->algor, aobj, ptype, pval))
 343         return 0;
 344     if (penc) {
 345         OPENSSL_free(pub->public_key->data);
 346         pub->public_key->data = penc;
 347         pub->public_key->length = penclen;
 348         /* Set number of unused bits to zero */
 349         pub->public_key->flags &= ~(ASN1_STRING_FLAG_BITS_LEFT | 0x07);
 350         pub->public_key->flags |= ASN1_STRING_FLAG_BITS_LEFT;
 351     }
 352     return 1;
 353 }
 354
 355 int X509_PUBKEY_get0_param(ASN1_OBJECT **ppkalg,
 356                            const unsigned char **pk, int *ppklen,
 357                            X509_ALGOR **pa, X509_PUBKEY *pub)
 358 {
 359     if (ppkalg)
 360         *ppkalg = pub->algor->algorithm;
 361     if (pk) {
 362         *pk = pub->public_key->data;
 363         *ppklen = pub->public_key->length;
 364     }
 365     if (pa)
 366         *pa = pub->algor;
 367     return 1;
 368 }
 369
 370 ASN1_BIT_STRING *X509_get0_pubkey_bitstr(const X509 *x)
 371 {
 372     if (x == NULL)
 373         return NULL;
 374     return x->cert_info.key->public_key;
 375 }