crypto/x509/x509_trs.c

   1 /* x509_trs.c */
   2 /*
   3  * Written by Dr Stephen N Henson (steve@openssl.org) for the OpenSSL project
   4  * 1999.
   5  */
   6 /* ====================================================================
   7  * Copyright (c) 1999 The OpenSSL Project.  All rights reserved.
   8  *
   9  * Redistribution and use in source and binary forms, with or without
  10  * modification, are permitted provided that the following conditions
  11  * are met:
  12  *
  13  * 1. Redistributions of source code must retain the above copyright
  14  *    notice, this list of conditions and the following disclaimer.
  15  *
  16  * 2. Redistributions in binary form must reproduce the above copyright
  17  *    notice, this list of conditions and the following disclaimer in
  18  *    the documentation and/or other materials provided with the
  19  *    distribution.
  20  *
  21  * 3. All advertising materials mentioning features or use of this
  22  *    software must display the following acknowledgment:
  23  *    "This product includes software developed by the OpenSSL Project
  24  *    for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"
  25  *
  26  * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
  27  *    endorse or promote products derived from this software without
  28  *    prior written permission. For written permission, please contact
  29  *    licensing@OpenSSL.org.
  30  *
  31  * 5. Products derived from this software may not be called "OpenSSL"
  32  *    nor may "OpenSSL" appear in their names without prior written
  33  *    permission of the OpenSSL Project.
  34  *
  35  * 6. Redistributions of any form whatsoever must retain the following
  36  *    acknowledgment:
  37  *    "This product includes software developed by the OpenSSL Project
  38  *    for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"
  39  *
  40  * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
  41  * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  42  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  43  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
  44  * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  45  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  46  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  47  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  48  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
  49  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  50  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
  51  * OF THE POSSIBILITY OF SUCH DAMAGE.
  52  * ====================================================================
  53  *
  54  * This product includes cryptographic software written by Eric Young
  55  * (eay@cryptsoft.com).  This product includes software written by Tim
  56  * Hudson (tjh@cryptsoft.com).
  57  *
  58  */
  59
  60 #include <stdio.h>
  61 #include "internal/cryptlib.h"
  62 #include <openssl/x509v3.h>
  63 #include "internal/x509_int.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 /*
  76  * WARNING: the following table should be kept in order of trust and without
  77  * any gaps so we can just subtract the minimum trust value to get an index
  78  * into the table
  79  */
  80
  81 static X509_TRUST trstandard[] = {
  82     {X509_TRUST_COMPAT, 0, trust_compat, "compatible", 0, NULL},
  83     {X509_TRUST_SSL_CLIENT, 0, trust_1oidany, "SSL Client", NID_client_auth,
  84      NULL},
  85     {X509_TRUST_SSL_SERVER, 0, trust_1oidany, "SSL Server", NID_server_auth,
  86      NULL},
  87     {X509_TRUST_EMAIL, 0, trust_1oidany, "S/MIME email", NID_email_protect,
  88      NULL},
  89     {X509_TRUST_OBJECT_SIGN, 0, trust_1oidany, "Object Signer", NID_code_sign,
  90      NULL},
  91     {X509_TRUST_OCSP_SIGN, 0, trust_1oid, "OCSP responder", NID_OCSP_sign,
  92      NULL},
  93     {X509_TRUST_OCSP_REQUEST, 0, trust_1oid, "OCSP request", NID_ad_OCSP,
  94      NULL},
  95     {X509_TRUST_TSA, 0, trust_1oidany, "TSA server", NID_time_stamp, NULL}
  96 };
  97
  98 #define X509_TRUST_COUNT        OSSL_NELEM(trstandard)
  99
 100 static STACK_OF(X509_TRUST) *trtable = NULL;
 101
 102 static int tr_cmp(const X509_TRUST *const *a, const X509_TRUST *const *b)
 103 {
 104     return (*a)->trust - (*b)->trust;
 105 }
 106
 107 int (*X509_TRUST_set_default(int (*trust) (int, X509 *, int))) (int, X509 *,
 108                                                                 int) {
 109     int (*oldtrust) (int, X509 *, int);
 110     oldtrust = default_trust;
 111     default_trust = trust;
 112     return oldtrust;
 113 }
 114
 115 int X509_check_trust(X509 *x, int id, int flags)
 116 {
 117     X509_TRUST *pt;
 118     int idx;
 119
 120     /* We get this as a default value */
 121     if (id == 0) {
 122         int rv;
 123         rv = obj_trust(NID_anyExtendedKeyUsage, x, 0);
 124         if (rv != X509_TRUST_UNTRUSTED)
 125             return rv;
 126         return trust_compat(NULL, x, 0);
 127     }
 128     idx = X509_TRUST_get_by_id(id);
 129     if (idx == -1)
 130         return default_trust(id, x, flags);
 131     pt = X509_TRUST_get0(idx);
 132     return pt->check_trust(pt, x, flags);
 133 }
 134
 135 int X509_TRUST_get_count(void)
 136 {
 137     if (!trtable)
 138         return X509_TRUST_COUNT;
 139     return sk_X509_TRUST_num(trtable) + X509_TRUST_COUNT;
 140 }
 141
 142 X509_TRUST *X509_TRUST_get0(int idx)
 143 {
 144     if (idx < 0)
 145         return NULL;
 146     if (idx < (int)X509_TRUST_COUNT)
 147         return trstandard + idx;
 148     return sk_X509_TRUST_value(trtable, idx - X509_TRUST_COUNT);
 149 }
 150
 151 int X509_TRUST_get_by_id(int id)
 152 {
 153     X509_TRUST tmp;
 154     int idx;
 155     if ((id >= X509_TRUST_MIN) && (id <= X509_TRUST_MAX))
 156         return id - X509_TRUST_MIN;
 157     tmp.trust = id;
 158     if (!trtable)
 159         return -1;
 160     idx = sk_X509_TRUST_find(trtable, &tmp);
 161     if (idx == -1)
 162         return -1;
 163     return idx + X509_TRUST_COUNT;
 164 }
 165
 166 int X509_TRUST_set(int *t, int trust)
 167 {
 168     if (X509_TRUST_get_by_id(trust) == -1) {
 169         X509err(X509_F_X509_TRUST_SET, X509_R_INVALID_TRUST);
 170         return 0;
 171     }
 172     *t = trust;
 173     return 1;
 174 }
 175
 176 int X509_TRUST_add(int id, int flags, int (*ck) (X509_TRUST *, X509 *, int),
 177                    char *name, int arg1, void *arg2)
 178 {
 179     int idx;
 180     X509_TRUST *trtmp;
 181     /*
 182      * This is set according to what we change: application can't set it
 183      */
 184     flags &= ~X509_TRUST_DYNAMIC;
 185     /* This will always be set for application modified trust entries */
 186     flags |= X509_TRUST_DYNAMIC_NAME;
 187     /* Get existing entry if any */
 188     idx = X509_TRUST_get_by_id(id);
 189     /* Need a new entry */
 190     if (idx == -1) {
 191         if ((trtmp = OPENSSL_malloc(sizeof(*trtmp))) == NULL) {
 192             X509err(X509_F_X509_TRUST_ADD, ERR_R_MALLOC_FAILURE);
 193             return 0;
 194         }
 195         trtmp->flags = X509_TRUST_DYNAMIC;
 196     } else
 197         trtmp = X509_TRUST_get0(idx);
 198
 199     /* OPENSSL_free existing name if dynamic */
 200     if (trtmp->flags & X509_TRUST_DYNAMIC_NAME)
 201         OPENSSL_free(trtmp->name);
 202     /* dup supplied name */
 203     if ((trtmp->name = OPENSSL_strdup(name)) == NULL) {
 204         X509err(X509_F_X509_TRUST_ADD, ERR_R_MALLOC_FAILURE);
 205         return 0;
 206     }
 207     /* Keep the dynamic flag of existing entry */
 208     trtmp->flags &= X509_TRUST_DYNAMIC;
 209     /* Set all other flags */
 210     trtmp->flags |= flags;
 211
 212     trtmp->trust = id;
 213     trtmp->check_trust = ck;
 214     trtmp->arg1 = arg1;
 215     trtmp->arg2 = arg2;
 216
 217     /* If its a new entry manage the dynamic table */
 218     if (idx == -1) {
 219         if (trtable == NULL
 220             && (trtable = sk_X509_TRUST_new(tr_cmp)) == NULL) {
 221             X509err(X509_F_X509_TRUST_ADD, ERR_R_MALLOC_FAILURE);
 222             return 0;
 223         }
 224         if (!sk_X509_TRUST_push(trtable, trtmp)) {
 225             X509err(X509_F_X509_TRUST_ADD, ERR_R_MALLOC_FAILURE);
 226             return 0;
 227         }
 228     }
 229     return 1;
 230 }
 231
 232 static void trtable_free(X509_TRUST *p)
 233 {
 234     if (!p)
 235         return;
 236     if (p->flags & X509_TRUST_DYNAMIC) {
 237         if (p->flags & X509_TRUST_DYNAMIC_NAME)
 238             OPENSSL_free(p->name);
 239         OPENSSL_free(p);
 240     }
 241 }
 242
 243 void X509_TRUST_cleanup(void)
 244 {
 245     unsigned int i;
 246     for (i = 0; i < X509_TRUST_COUNT; i++)
 247         trtable_free(trstandard + i);
 248     sk_X509_TRUST_pop_free(trtable, trtable_free);
 249     trtable = NULL;
 250 }
 251
 252 int X509_TRUST_get_flags(X509_TRUST *xp)
 253 {
 254     return xp->flags;
 255 }
 256
 257 char *X509_TRUST_get0_name(X509_TRUST *xp)
 258 {
 259     return xp->name;
 260 }
 261
 262 int X509_TRUST_get_trust(X509_TRUST *xp)
 263 {
 264     return xp->trust;
 265 }
 266
 267 static int trust_1oidany(X509_TRUST *trust, X509 *x, int flags)
 268 {
 269     if (x->aux && (x->aux->trust || x->aux->reject))
 270         return obj_trust(trust->arg1, x, flags);
 271     /*
 272      * we don't have any trust settings: for compatibility we return trusted
 273      * if it is self signed
 274      */
 275     return trust_compat(trust, x, flags);
 276 }
 277
 278 static int trust_1oid(X509_TRUST *trust, X509 *x, int flags)
 279 {
 280     if (x->aux)
 281         return obj_trust(trust->arg1, x, flags);
 282     return X509_TRUST_UNTRUSTED;
 283 }
 284
 285 static int trust_compat(X509_TRUST *trust, X509 *x, int flags)
 286 {
 287     X509_check_purpose(x, -1, 0);
 288     if (x->ex_flags & EXFLAG_SS)
 289         return X509_TRUST_TRUSTED;
 290     else
 291         return X509_TRUST_UNTRUSTED;
 292 }
 293
 294 static int obj_trust(int id, X509 *x, int flags)
 295 {
 296     ASN1_OBJECT *obj;
 297     int i;
 298     X509_CERT_AUX *ax;
 299     ax = x->aux;
 300     if (!ax)
 301         return X509_TRUST_UNTRUSTED;
 302     if (ax->reject) {
 303         for (i = 0; i < sk_ASN1_OBJECT_num(ax->reject); i++) {
 304             obj = sk_ASN1_OBJECT_value(ax->reject, i);
 305             if (OBJ_obj2nid(obj) == id)
 306                 return X509_TRUST_REJECTED;
 307         }
 308     }
 309     if (ax->trust) {
 310         for (i = 0; i < sk_ASN1_OBJECT_num(ax->trust); i++) {
 311             obj = sk_ASN1_OBJECT_value(ax->trust, i);
 312             if (OBJ_obj2nid(obj) == id)
 313                 return X509_TRUST_TRUSTED;
 314         }
 315         /*
 316          * Reject when explicit trust EKU are set and none match.
 317          *
 318          * Returning untrusted is enough for for full chains that end in
 319          * self-signed roots, because when explicit trust is specified it
 320          * suppresses the default blanket trust of self-signed objects.
 321          *
 322          * But for partial chains, this is not enough, because absent a similar
 323          * trust-self-signed policy, non matching EKUs are indistinguishable
 324          * from lack of EKU constraints.
 325          *
 326          * Therefore, failure to match any trusted purpose must trigger an
 327          * explicit reject.
 328          */
 329         return X509_TRUST_REJECTED;
 330     }
 331     return X509_TRUST_UNTRUSTED;
 332 }