lib/libcrypto/x509/x509_trs.c

   1 /* $OpenBSD: x509_trs.c,v 1.23 2018/05/18 18:40:38 tb Exp $ */
   2 /* Written by Dr Stephen N Henson (steve@openssl.org) for the OpenSSL
   3  * project 1999.
   4  */
   5 /* ====================================================================
   6  * Copyright (c) 1999 The OpenSSL Project.  All rights reserved.
   7  *
   8  * Redistribution and use in source and binary forms, with or without
   9  * modification, are permitted provided that the following conditions
  10  * are met:
  11  *
  12  * 1. Redistributions of source code must retain the above copyright
  13  *    notice, this list of conditions and the following disclaimer.
  14  *
  15  * 2. Redistributions in binary form must reproduce the above copyright
  16  *    notice, this list of conditions and the following disclaimer in
  17  *    the documentation and/or other materials provided with the
  18  *    distribution.
  19  *
  20  * 3. All advertising materials mentioning features or use of this
  21  *    software must display the following acknowledgment:
  22  *    "This product includes software developed by the OpenSSL Project
  23  *    for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"
  24  *
  25  * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
  26  *    endorse or promote products derived from this software without
  27  *    prior written permission. For written permission, please contact
  28  *    licensing@OpenSSL.org.
  29  *
  30  * 5. Products derived from this software may not be called "OpenSSL"
  31  *    nor may "OpenSSL" appear in their names without prior written
  32  *    permission of the OpenSSL Project.
  33  *
  34  * 6. Redistributions of any form whatsoever must retain the following
  35  *    acknowledgment:
  36  *    "This product includes software developed by the OpenSSL Project
  37  *    for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"
  38  *
  39  * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
  40  * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  41  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  42  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
  43  * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  44  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  45  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  46  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  47  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
  48  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  49  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
  50  * OF THE POSSIBILITY OF SUCH DAMAGE.
  51  * ====================================================================
  52  *
  53  * This product includes cryptographic software written by Eric Young
  54  * (eay@cryptsoft.com).  This product includes software written by Tim
  55  * Hudson (tjh@cryptsoft.com).
  56  *
  57  */
  58
  59 #include <stdio.h>
  60 #include <string.h>
  61
  62 #include <openssl/err.h>
  63 #include <openssl/x509v3.h>
  64
  65 static int tr_cmp(const X509_TRUST * const *a, const X509_TRUST * const *b);
  66 static void trtable_free(X509_TRUST *p);
  67
  68 static int trust_1oidany(X509_TRUST *trust, X509 *x, int flags);
  69 static int trust_1oid(X509_TRUST *trust, X509 *x, int flags);
  70 static int trust_compat(X509_TRUST *trust, X509 *x, int flags);
  71
  72 static int obj_trust(int id, X509 *x, int flags);
  73 static int (*default_trust)(int id, X509 *x, int flags) = obj_trust;
  74
  75 /* WARNING: the following table should be kept in order of trust
  76  * and without any gaps so we can just subtract the minimum trust
  77  * value to get an index into the table
  78  */
  79
  80 static X509_TRUST trstandard[] = {
  81         {X509_TRUST_COMPAT, 0, trust_compat, "compatible", 0, NULL},
  82         {X509_TRUST_SSL_CLIENT, 0, trust_1oidany, "SSL Client", NID_client_auth, NULL},
  83         {X509_TRUST_SSL_SERVER, 0, trust_1oidany, "SSL Server", NID_server_auth, NULL},
  84         {X509_TRUST_EMAIL, 0, trust_1oidany, "S/MIME email", NID_email_protect, NULL},
  85         {X509_TRUST_OBJECT_SIGN, 0, trust_1oidany, "Object Signer", NID_code_sign, NULL},
  86         {X509_TRUST_OCSP_SIGN, 0, trust_1oid, "OCSP responder", NID_OCSP_sign, NULL},
  87         {X509_TRUST_OCSP_REQUEST, 0, trust_1oid, "OCSP request", NID_ad_OCSP, NULL},
  88         {X509_TRUST_TSA, 0, trust_1oidany, "TSA server", NID_time_stamp, NULL}
  89 };
  90
  91 #define X509_TRUST_COUNT        (sizeof(trstandard)/sizeof(X509_TRUST))
  92
  93 static STACK_OF(X509_TRUST) *trtable = NULL;
  94
  95 static int
  96 tr_cmp(const X509_TRUST * const *a, const X509_TRUST * const *b)
  97 {
  98         return (*a)->trust - (*b)->trust;
  99 }
 100
 101 int
 102 (*X509_TRUST_set_default(int (*trust)(int , X509 *, int)))(int, X509 *, int)
 103 {
 104         int (*oldtrust)(int , X509 *, int);
 105
 106         oldtrust = default_trust;
 107         default_trust = trust;
 108         return oldtrust;
 109 }
 110
 111 int
 112 X509_check_trust(X509 *x, int id, int flags)
 113 {
 114         X509_TRUST *pt;
 115         int idx;
 116
 117         if (id == -1)
 118                 return 1;
 119         /*
 120          * XXX beck/jsing This enables self signed certs to be trusted for
 121          * an unspecified id/trust flag value (this is NOT the
 122          * X509_TRUST_DEFAULT), which was the longstanding
 123          * openssl behaviour. boringssl does not have this behaviour.
 124          *
 125          * This should be revisited, but changing the default "not default"
 126          * may break things.
 127          */
 128         if (id == 0) {
 129                 int rv;
 130                 rv = obj_trust(NID_anyExtendedKeyUsage, x, 0);
 131                 if (rv != X509_TRUST_UNTRUSTED)
 132                         return rv;
 133                 return trust_compat(NULL, x, 0);
 134         }
 135         idx = X509_TRUST_get_by_id(id);
 136         if (idx == -1)
 137                 return default_trust(id, x, flags);
 138         pt = X509_TRUST_get0(idx);
 139         return pt->check_trust(pt, x, flags);
 140 }
 141
 142 int
 143 X509_TRUST_get_count(void)
 144 {
 145         if (!trtable)
 146                 return X509_TRUST_COUNT;
 147         return sk_X509_TRUST_num(trtable) + X509_TRUST_COUNT;
 148 }
 149
 150 X509_TRUST *
 151 X509_TRUST_get0(int idx)
 152 {
 153         if (idx < 0)
 154                 return NULL;
 155         if (idx < (int)X509_TRUST_COUNT)
 156                 return trstandard + idx;
 157         return sk_X509_TRUST_value(trtable, idx - X509_TRUST_COUNT);
 158 }
 159
 160 int
 161 X509_TRUST_get_by_id(int id)
 162 {
 163         X509_TRUST tmp;
 164         int idx;
 165
 166         if ((id >= X509_TRUST_MIN) && (id <= X509_TRUST_MAX))
 167                 return id - X509_TRUST_MIN;
 168         tmp.trust = id;
 169         if (!trtable)
 170                 return -1;
 171         idx = sk_X509_TRUST_find(trtable, &tmp);
 172         if (idx == -1)
 173                 return -1;
 174         return idx + X509_TRUST_COUNT;
 175 }
 176
 177 int
 178 X509_TRUST_set(int *t, int trust)
 179 {
 180         if (X509_TRUST_get_by_id(trust) == -1) {
 181                 X509error(X509_R_INVALID_TRUST);
 182                 return 0;
 183         }
 184         *t = trust;
 185         return 1;
 186 }
 187
 188 int
 189 X509_TRUST_add(int id, int flags, int (*ck)(X509_TRUST *, X509 *, int),
 190     const char *name, int arg1, void *arg2)
 191 {
 192         int idx;
 193         X509_TRUST *trtmp;
 194         char *name_dup;
 195
 196         /* This is set according to what we change: application can't set it */
 197         flags &= ~X509_TRUST_DYNAMIC;
 198         /* This will always be set for application modified trust entries */
 199         flags |= X509_TRUST_DYNAMIC_NAME;
 200         /* Get existing entry if any */
 201         idx = X509_TRUST_get_by_id(id);
 202         /* Need a new entry */
 203         if (idx == -1) {
 204                 if (!(trtmp = malloc(sizeof(X509_TRUST)))) {
 205                         X509error(ERR_R_MALLOC_FAILURE);
 206                         return 0;
 207                 }
 208                 trtmp->flags = X509_TRUST_DYNAMIC;
 209         } else {
 210                 trtmp = X509_TRUST_get0(idx);
 211                 if (trtmp == NULL) {
 212                         X509error(X509_R_INVALID_TRUST);
 213                         return 0;
 214                 }
 215         }
 216
 217         if ((name_dup = strdup(name)) == NULL)
 218                 goto err;
 219
 220         /* free existing name if dynamic */
 221         if (trtmp->flags & X509_TRUST_DYNAMIC_NAME)
 222                 free(trtmp->name);
 223         /* dup supplied name */
 224         trtmp->name = name_dup;
 225         /* Keep the dynamic flag of existing entry */
 226         trtmp->flags &= X509_TRUST_DYNAMIC;
 227         /* Set all other flags */
 228         trtmp->flags |= flags;
 229
 230         trtmp->trust = id;
 231         trtmp->check_trust = ck;
 232         trtmp->arg1 = arg1;
 233         trtmp->arg2 = arg2;
 234
 235         /* If it's a new entry, manage the dynamic table */
 236         if (idx == -1) {
 237                 if (trtable == NULL &&
 238                     (trtable = sk_X509_TRUST_new(tr_cmp)) == NULL)
 239                         goto err;
 240                 if (sk_X509_TRUST_push(trtable, trtmp) == 0)
 241                         goto err;
 242         }
 243         return 1;
 244
 245 err:
 246         free(name_dup);
 247         if (idx == -1)
 248                 free(trtmp);
 249         X509error(ERR_R_MALLOC_FAILURE);
 250         return 0;
 251 }
 252
 253 static void
 254 trtable_free(X509_TRUST *p)
 255 {
 256         if (!p)
 257                 return;
 258         if (p->flags & X509_TRUST_DYNAMIC) {
 259                 if (p->flags & X509_TRUST_DYNAMIC_NAME)
 260                         free(p->name);
 261                 free(p);
 262         }
 263 }
 264
 265 void
 266 X509_TRUST_cleanup(void)
 267 {
 268         unsigned int i;
 269
 270         for (i = 0; i < X509_TRUST_COUNT; i++)
 271                 trtable_free(trstandard + i);
 272         sk_X509_TRUST_pop_free(trtable, trtable_free);
 273         trtable = NULL;
 274 }
 275
 276 int
 277 X509_TRUST_get_flags(const X509_TRUST *xp)
 278 {
 279         return xp->flags;
 280 }
 281
 282 char *
 283 X509_TRUST_get0_name(const X509_TRUST *xp)
 284 {
 285         return xp->name;
 286 }
 287
 288 int
 289 X509_TRUST_get_trust(const X509_TRUST *xp)
 290 {
 291         return xp->trust;
 292 }
 293
 294 static int
 295 trust_1oidany(X509_TRUST *trust, X509 *x, int flags)
 296 {
 297         if (x->aux && (x->aux->trust || x->aux->reject))
 298                 return obj_trust(trust->arg1, x, flags);
 299         /* we don't have any trust settings: for compatibility
 300          * we return trusted if it is self signed
 301          */
 302         return trust_compat(trust, x, flags);
 303 }
 304
 305 static int
 306 trust_1oid(X509_TRUST *trust, X509 *x, int flags)
 307 {
 308         if (x->aux)
 309                 return obj_trust(trust->arg1, x, flags);
 310         return X509_TRUST_UNTRUSTED;
 311 }
 312
 313 static int
 314 trust_compat(X509_TRUST *trust, X509 *x, int flags)
 315 {
 316         X509_check_purpose(x, -1, 0);
 317         if (x->ex_flags & EXFLAG_SS)
 318                 return X509_TRUST_TRUSTED;
 319         else
 320                 return X509_TRUST_UNTRUSTED;
 321 }
 322
 323 static int
 324 obj_trust(int id, X509 *x, int flags)
 325 {
 326         ASN1_OBJECT *obj;
 327         int i;
 328         X509_CERT_AUX *ax;
 329
 330         ax = x->aux;
 331         if (!ax)
 332                 return X509_TRUST_UNTRUSTED;
 333         if (ax->reject) {
 334                 for (i = 0; i < sk_ASN1_OBJECT_num(ax->reject); i++) {
 335                         obj = sk_ASN1_OBJECT_value(ax->reject, i);
 336                         if (OBJ_obj2nid(obj) == id)
 337                                 return X509_TRUST_REJECTED;
 338                 }
 339         }
 340         if (ax->trust) {
 341                 for (i = 0; i < sk_ASN1_OBJECT_num(ax->trust); i++) {
 342                         obj = sk_ASN1_OBJECT_value(ax->trust, i);
 343                         if (OBJ_obj2nid(obj) == id)
 344                                 return X509_TRUST_TRUSTED;
 345                 }
 346         }
 347         return X509_TRUST_UNTRUSTED;
 348 }