crypto/x509/x509_trs.c

   1 /*
   2  * Written by Dr Stephen N Henson (steve@openssl.org) for the OpenSSL project
   3  * 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 "internal/cryptlib.h"
  61 #include <openssl/x509v3.h>
  62 #include "internal/x509_int.h"
  63
  64 static int tr_cmp(const X509_TRUST *const *a, const X509_TRUST *const *b);
  65 static void trtable_free(X509_TRUST *p);
  66
  67 static int trust_1oidany(X509_TRUST *trust, X509 *x, int flags);
  68 static int trust_1oid(X509_TRUST *trust, X509 *x, int flags);
  69 static int trust_compat(X509_TRUST *trust, X509 *x, int flags);
  70
  71 static int obj_trust(int id, X509 *x, int flags);
  72 static int (*default_trust) (int id, X509 *x, int flags) = obj_trust;
  73
  74 /*
  75  * WARNING: the following table should be kept in order of trust and without
  76  * any gaps so we can just subtract the minimum trust value to get an index
  77  * 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,
  83      NULL},
  84     {X509_TRUST_SSL_SERVER, 0, trust_1oidany, "SSL Server", NID_server_auth,
  85      NULL},
  86     {X509_TRUST_EMAIL, 0, trust_1oidany, "S/MIME email", NID_email_protect,
  87      NULL},
  88     {X509_TRUST_OBJECT_SIGN, 0, trust_1oidany, "Object Signer", NID_code_sign,
  89      NULL},
  90     {X509_TRUST_OCSP_SIGN, 0, trust_1oid, "OCSP responder", NID_OCSP_sign,
  91      NULL},
  92     {X509_TRUST_OCSP_REQUEST, 0, trust_1oid, "OCSP request", NID_ad_OCSP,
  93      NULL},
  94     {X509_TRUST_TSA, 0, trust_1oidany, "TSA server", NID_time_stamp, NULL}
  95 };
  96
  97 #define X509_TRUST_COUNT        OSSL_NELEM(trstandard)
  98
  99 static STACK_OF(X509_TRUST) *trtable = NULL;
 100
 101 static int tr_cmp(const X509_TRUST *const *a, const X509_TRUST *const *b)
 102 {
 103     return (*a)->trust - (*b)->trust;
 104 }
 105
 106 int (*X509_TRUST_set_default(int (*trust) (int, X509 *, int))) (int, X509 *,
 107                                                                 int) {
 108     int (*oldtrust) (int, X509 *, int);
 109     oldtrust = default_trust;
 110     default_trust = trust;
 111     return oldtrust;
 112 }
 113
 114 int X509_check_trust(X509 *x, int id, int flags)
 115 {
 116     X509_TRUST *pt;
 117     int idx;
 118
 119     /* We get this as a default value */
 120     if (id == 0) {
 121         int rv;
 122         rv = obj_trust(NID_anyExtendedKeyUsage, x, 0);
 123         if (rv != X509_TRUST_UNTRUSTED)
 124             return rv;
 125         return trust_compat(NULL, x, 0);
 126     }
 127     idx = X509_TRUST_get_by_id(id);
 128     if (idx == -1)
 129         return default_trust(id, x, flags);
 130     pt = X509_TRUST_get0(idx);
 131     return pt->check_trust(pt, x, flags);
 132 }
 133
 134 int X509_TRUST_get_count(void)
 135 {
 136     if (!trtable)
 137         return X509_TRUST_COUNT;
 138     return sk_X509_TRUST_num(trtable) + X509_TRUST_COUNT;
 139 }
 140
 141 X509_TRUST *X509_TRUST_get0(int idx)
 142 {
 143     if (idx < 0)
 144         return NULL;
 145     if (idx < (int)X509_TRUST_COUNT)
 146         return trstandard + idx;
 147     return sk_X509_TRUST_value(trtable, idx - X509_TRUST_COUNT);
 148 }
 149
 150 int X509_TRUST_get_by_id(int id)
 151 {
 152     X509_TRUST tmp;
 153     int idx;
 154     if ((id >= X509_TRUST_MIN) && (id <= X509_TRUST_MAX))
 155         return id - X509_TRUST_MIN;
 156     tmp.trust = id;
 157     if (!trtable)
 158         return -1;
 159     idx = sk_X509_TRUST_find(trtable, &tmp);
 160     if (idx == -1)
 161         return -1;
 162     return idx + X509_TRUST_COUNT;
 163 }
 164
 165 int X509_TRUST_set(int *t, int trust)
 166 {
 167     if (X509_TRUST_get_by_id(trust) == -1) {
 168         X509err(X509_F_X509_TRUST_SET, X509_R_INVALID_TRUST);
 169         return 0;
 170     }
 171     *t = trust;
 172     return 1;
 173 }
 174
 175 int X509_TRUST_add(int id, int flags, int (*ck) (X509_TRUST *, X509 *, int),
 176                    char *name, int arg1, void *arg2)
 177 {
 178     int idx;
 179     X509_TRUST *trtmp;
 180     /*
 181      * This is set according to what we change: application can't set it
 182      */
 183     flags &= ~X509_TRUST_DYNAMIC;
 184     /* This will always be set for application modified trust entries */
 185     flags |= X509_TRUST_DYNAMIC_NAME;
 186     /* Get existing entry if any */
 187     idx = X509_TRUST_get_by_id(id);
 188     /* Need a new entry */
 189     if (idx == -1) {
 190         if ((trtmp = OPENSSL_malloc(sizeof(*trtmp))) == NULL) {
 191             X509err(X509_F_X509_TRUST_ADD, ERR_R_MALLOC_FAILURE);
 192             return 0;
 193         }
 194         trtmp->flags = X509_TRUST_DYNAMIC;
 195     } else
 196         trtmp = X509_TRUST_get0(idx);
 197
 198     /* OPENSSL_free existing name if dynamic */
 199     if (trtmp->flags & X509_TRUST_DYNAMIC_NAME)
 200         OPENSSL_free(trtmp->name);
 201     /* dup supplied name */
 202     if ((trtmp->name = OPENSSL_strdup(name)) == NULL) {
 203         X509err(X509_F_X509_TRUST_ADD, ERR_R_MALLOC_FAILURE);
 204         return 0;
 205     }
 206     /* Keep the dynamic flag of existing entry */
 207     trtmp->flags &= X509_TRUST_DYNAMIC;
 208     /* Set all other flags */
 209     trtmp->flags |= flags;
 210
 211     trtmp->trust = id;
 212     trtmp->check_trust = ck;
 213     trtmp->arg1 = arg1;
 214     trtmp->arg2 = arg2;
 215
 216     /* If its a new entry manage the dynamic table */
 217     if (idx == -1) {
 218         if (trtable == NULL
 219             && (trtable = sk_X509_TRUST_new(tr_cmp)) == NULL) {
 220             X509err(X509_F_X509_TRUST_ADD, ERR_R_MALLOC_FAILURE);
 221             return 0;
 222         }
 223         if (!sk_X509_TRUST_push(trtable, trtmp)) {
 224             X509err(X509_F_X509_TRUST_ADD, ERR_R_MALLOC_FAILURE);
 225             return 0;
 226         }
 227     }
 228     return 1;
 229 }
 230
 231 static void trtable_free(X509_TRUST *p)
 232 {
 233     if (!p)
 234         return;
 235     if (p->flags & X509_TRUST_DYNAMIC) {
 236         if (p->flags & X509_TRUST_DYNAMIC_NAME)
 237             OPENSSL_free(p->name);
 238         OPENSSL_free(p);
 239     }
 240 }
 241
 242 void X509_TRUST_cleanup(void)
 243 {
 244     unsigned int i;
 245     for (i = 0; i < X509_TRUST_COUNT; i++)
 246         trtable_free(trstandard + i);
 247     sk_X509_TRUST_pop_free(trtable, trtable_free);
 248     trtable = NULL;
 249 }
 250
 251 int X509_TRUST_get_flags(X509_TRUST *xp)
 252 {
 253     return xp->flags;
 254 }
 255
 256 char *X509_TRUST_get0_name(X509_TRUST *xp)
 257 {
 258     return xp->name;
 259 }
 260
 261 int X509_TRUST_get_trust(X509_TRUST *xp)
 262 {
 263     return xp->trust;
 264 }
 265
 266 static int trust_1oidany(X509_TRUST *trust, X509 *x, int flags)
 267 {
 268     if (x->aux && (x->aux->trust || x->aux->reject))
 269         return obj_trust(trust->arg1, x, flags);
 270     /*
 271      * we don't have any trust settings: for compatibility we return trusted
 272      * if it is self signed
 273      */
 274     return trust_compat(trust, x, flags);
 275 }
 276
 277 static int trust_1oid(X509_TRUST *trust, X509 *x, int flags)
 278 {
 279     if (x->aux && (x->aux->trust || x->aux->reject))
 280         return obj_trust(trust->arg1, x, flags);
 281     return X509_TRUST_UNTRUSTED;
 282 }
 283
 284 static int trust_compat(X509_TRUST *trust, X509 *x, int flags)
 285 {
 286     /* Call for side-effect of computing hash and caching extensions */
 287     X509_check_purpose(x, -1, 0);
 288     if ((flags & X509_TRUST_NO_SS_COMPAT) == 0 && 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     X509_CERT_AUX *ax = x->aux;
 297     int i;
 298
 299     if (!ax)
 300         return X509_TRUST_UNTRUSTED;
 301     if (ax->reject) {
 302         for (i = 0; i < sk_ASN1_OBJECT_num(ax->reject); i++) {
 303             ASN1_OBJECT *obj = sk_ASN1_OBJECT_value(ax->reject, i);
 304             int nid = OBJ_obj2nid(obj);
 305
 306             if (nid == id || nid == NID_anyExtendedKeyUsage)
 307                 return X509_TRUST_REJECTED;
 308         }
 309     }
 310     if (ax->trust) {
 311         for (i = 0; i < sk_ASN1_OBJECT_num(ax->trust); i++) {
 312             ASN1_OBJECT *obj = sk_ASN1_OBJECT_value(ax->trust, i);
 313             int nid = OBJ_obj2nid(obj);
 314
 315             if (nid == id || nid == NID_anyExtendedKeyUsage)
 316                 return X509_TRUST_TRUSTED;
 317         }
 318         /*
 319          * Reject when explicit trust EKU are set and none match.
 320          *
 321          * Returning untrusted is enough for for full chains that end in
 322          * self-signed roots, because when explicit trust is specified it
 323          * suppresses the default blanket trust of self-signed objects.
 324          *
 325          * But for partial chains, this is not enough, because absent a similar
 326          * trust-self-signed policy, non matching EKUs are indistinguishable
 327          * from lack of EKU constraints.
 328          *
 329          * Therefore, failure to match any trusted purpose must trigger an
 330          * explicit reject.
 331          */
 332         return X509_TRUST_REJECTED;
 333     }
 334     return X509_TRUST_UNTRUSTED;
 335 }