Tidy up CRL handling by checking for critical extensions when it is
[openssl.git] / crypto / x509 / x509_vfy.c
index 57113672328165652e4cb6ffb1b2dbdb8c38d95f..d1aa3dafd6d378f830e304173dd48c376a794681 100644 (file)
@@ -78,6 +78,8 @@ static int check_trust(X509_STORE_CTX *ctx);
 static int check_revocation(X509_STORE_CTX *ctx);
 static int check_cert(X509_STORE_CTX *ctx);
 static int check_policy(X509_STORE_CTX *ctx);
+static int crl_akid_check(X509_STORE_CTX *ctx, AUTHORITY_KEYID *akid);
+static int idp_check_scope(X509 *x, X509_CRL *crl);
 static int internal_verify(X509_STORE_CTX *ctx);
 const char *X509_version="X.509" OPENSSL_VERSION_PTEXT;
 
@@ -649,30 +651,81 @@ static int check_crl_time(X509_STORE_CTX *ctx, X509_CRL *crl, int notify)
        return 1;
        }
 
-/* Lookup CRLs from the supplied list. Look for matching isser name
- * and validity. If we can't find a valid CRL return the last one
- * with matching name. This gives more meaningful error codes. Otherwise
- * we'd get a CRL not found error if a CRL existed with matching name but
- * was invalid.
+/* Based on a set of possible CRLs decide which one is best suited
+ * to handle the current certificate. This is determined by a number
+ * of criteria. If any of the "must" criteria is not satisfied then
+ * the candidate CRL is rejected. If all "must" and all "should" are
+ * satisfied the CRL is accepted. If no CRL satisfies all criteria then
+ * a "best CRL" is used to provide some meaningful error information.
+ *
+ * CRL issuer name must match "nm" if not NULL.
+ * If IDP is present:
+ *   a. it must be consistent.
+ *   b. onlyuser, onlyCA, onlyAA should match certificate being checked.
+ *   c. indirectCRL must be FALSE.
+ *   d. onlysomereason must be absent.
+ *   e. if name present a DP in certificate CRLDP must match.
+ * If AKID present it should match certificate AKID.
+ * Check time should fall between lastUpdate and nextUpdate.
  */
 
+/* IDP name field matches CRLDP or IDP name not present */
+#define CRL_SCORE_SCOPE                4
+/* AKID present and matches cert, or AKID not present */
+#define CRL_SCORE_AKID         2
+/* times OK */
+#define CRL_SCORE_TIME         1
+
+#define CRL_SCORE_ALL          7
+
+/* IDP flags which cause a CRL to be rejected */
+
+#define IDP_REJECT     (IDP_INVALID|IDP_INDIRECT|IDP_REASONS)
+
 static int get_crl_sk(X509_STORE_CTX *ctx, X509_CRL **pcrl,
                        X509_NAME *nm, STACK_OF(X509_CRL) *crls)
        {
-       int i;
+       int i, crl_score, best_score = -1;
        X509_CRL *crl, *best_crl = NULL;
        for (i = 0; i < sk_X509_CRL_num(crls); i++)
                {
+               crl_score = 0;
                crl = sk_X509_CRL_value(crls, i);
-               if (X509_NAME_cmp(nm, X509_CRL_get_issuer(crl)))
+               if (nm && X509_NAME_cmp(nm, X509_CRL_get_issuer(crl)))
                        continue;
                if (check_crl_time(ctx, crl, 0))
+                       crl_score |= CRL_SCORE_TIME;
+
+               if (crl->idp_flags & IDP_PRESENT)
+                       {
+                       if (crl->idp_flags & IDP_REJECT)
+                               continue;
+                       if (idp_check_scope(ctx->current_cert, crl))
+                               crl_score |= CRL_SCORE_SCOPE;
+                       }
+               else
+                       crl_score |= CRL_SCORE_SCOPE;
+
+               if (crl->akid)
+                       {
+                       if (crl_akid_check(ctx, crl->akid))
+                               crl_score |= CRL_SCORE_AKID;
+                       }
+               else
+                       crl_score |= CRL_SCORE_AKID;
+
+               if (crl_score == CRL_SCORE_ALL)
                        {
                        *pcrl = crl;
-                       CRYPTO_add(&crl->references, 1, CRYPTO_LOCK_X509);
+                       CRYPTO_add(&crl->references, 1, CRYPTO_LOCK_X509_CRL);
                        return 1;
                        }
-               best_crl = crl;
+
+               if (crl_score > best_score)
+                       {
+                       best_crl = crl;
+                       best_score = crl_score;
+                       }
                }
        if (best_crl)
                {
@@ -683,14 +736,76 @@ static int get_crl_sk(X509_STORE_CTX *ctx, X509_CRL **pcrl,
        return 0;
        }
 
-/* Retrieve CRL corresponding to certificate: currently just a
- * subject lookup: maybe use AKID later...
+static int crl_akid_check(X509_STORE_CTX *ctx, AUTHORITY_KEYID *akid)
+       {
+       int cidx = ctx->error_depth;
+       if (cidx != sk_X509_num(ctx->chain) - 1)
+               cidx++;
+       if (X509_check_akid(sk_X509_value(ctx->chain, cidx), akid) == X509_V_OK)
+               return 1;
+       return 0;
+       }
+
+
+/* Check IDP name matches at least one CRLDP name */
+
+static int idp_check_scope(X509 *x, X509_CRL *crl)
+       {
+       int i, j, k;
+       GENERAL_NAMES *inames, *dnames;
+       if (crl->idp_flags & IDP_ONLYATTR)
+               return 0;
+       if (x->ex_flags & EXFLAG_CA)
+               {
+               if (crl->idp_flags & IDP_ONLYUSER)
+                       return 0;
+               }
+       else
+               {
+               if (crl->idp_flags & IDP_ONLYCA)
+                       return 0;
+               }
+       if (!crl->idp->distpoint)
+               return 1;
+       if (crl->idp->distpoint->type != 0)
+               return 1;
+       if (!x->crldp)
+               return 0;
+       inames = crl->idp->distpoint->name.fullname;
+       for (i = 0; i < sk_GENERAL_NAME_num(inames); i++)
+               {
+               GENERAL_NAME *igen = sk_GENERAL_NAME_value(inames, i);
+               for (j = 0; j < sk_DIST_POINT_num(x->crldp); j++)
+                       {
+                       DIST_POINT *dp = sk_DIST_POINT_value(x->crldp, j);
+                       /* We don't handle these at present */
+                       if (dp->reasons || dp->CRLissuer)
+                               continue;
+                       if (!dp->distpoint || (dp->distpoint->type != 0))
+                               continue;
+                       dnames = dp->distpoint->name.fullname;
+                       for (k = 0; k < sk_GENERAL_NAME_num(dnames); k++)
+                               {
+                               GENERAL_NAME *cgen =
+                                       sk_GENERAL_NAME_value(dnames, k);
+                               if (!GENERAL_NAME_cmp(igen, cgen))
+                                       return 1;
+                               }
+                       }
+               }
+       return 0;
+       }
+
+/* Retrieve CRL corresponding to current certificate. Currently only
+ * one CRL is retrieved. Multiple CRLs may be needed if we handle
+ * CRLs partitioned on reason code later.
  */
+       
 static int get_crl(X509_STORE_CTX *ctx, X509_CRL **pcrl, X509 *x)
        {
        int ok;
        X509_CRL *crl = NULL;
-       X509_OBJECT xobj;
+       STACK_OF(X509_CRL) *skcrl;
        X509_NAME *nm;
        nm = X509_get_issuer_name(x);
        ok = get_crl_sk(ctx, &crl, nm, ctx->crls);
@@ -700,11 +815,13 @@ static int get_crl(X509_STORE_CTX *ctx, X509_CRL **pcrl, X509 *x)
                return 1;
                }
 
-       ok = X509_STORE_get_by_subject(ctx, X509_LU_CRL, nm, &xobj);
+       /* Lookup CRLs from store */
 
-       if (!ok)
+       skcrl = ctx->lookup_crls(ctx, nm);
+
+       /* If no CRLs found and a near match from get_crl_sk use that */
+       if (!skcrl)
                {
-               /* If we got a near match from get_crl_sk use that */
                if (crl)
                        {
                        *pcrl = crl;
@@ -713,10 +830,18 @@ static int get_crl(X509_STORE_CTX *ctx, X509_CRL **pcrl, X509 *x)
                return 0;
                }
 
-       *pcrl = xobj.data.crl;
+       get_crl_sk(ctx, &crl, NULL, skcrl);
+
+       sk_X509_CRL_pop_free(skcrl, X509_CRL_free);
+
+       /* If we got any kind of CRL use it and return success */
        if (crl)
-               X509_CRL_free(crl);
-       return 1;
+               {
+               *pcrl = crl;
+               return 1;
+               }
+
+       return 0;
        }
 
 /* Check CRL validity */
@@ -755,6 +880,28 @@ static int check_crl(X509_STORE_CTX *ctx, X509_CRL *crl)
                        if(!ok) goto err;
                        }
 
+               if (crl->idp_flags & IDP_PRESENT)
+                       {
+                       if (crl->idp_flags & IDP_INVALID)
+                               {
+                               ctx->error = X509_V_ERR_INVALID_EXTENSION;
+                               ok = ctx->verify_cb(0, ctx);
+                               if(!ok) goto err;
+                               }
+                       if (crl->idp_flags & (IDP_REASONS|IDP_INDIRECT))
+                               {
+                               ctx->error = X509_V_ERR_UNSUPPORTED_EXTENSION_FEATURE;
+                               ok = ctx->verify_cb(0, ctx);
+                               if(!ok) goto err;
+                               }
+                       if (!idp_check_scope(ctx->current_cert, crl))
+                               {
+                               ctx->error = X509_V_ERR_DIFFERENT_CRL_SCOPE;
+                               ok = ctx->verify_cb(0, ctx);
+                               if(!ok) goto err;
+                               }
+                       }
+
                /* Attempt to get issuer certificate public key */
                ikey = X509_get_pubkey(issuer);
 
@@ -790,56 +937,29 @@ static int check_crl(X509_STORE_CTX *ctx, X509_CRL *crl)
 /* Check certificate against CRL */
 static int cert_crl(X509_STORE_CTX *ctx, X509_CRL *crl, X509 *x)
        {
-       int idx, ok;
-       X509_REVOKED rtmp;
-       STACK_OF(X509_EXTENSION) *exts;
-       X509_EXTENSION *ext;
-       /* Look for serial number of certificate in CRL */
-       rtmp.serialNumber = X509_get_serialNumber(x);
-       /* Sort revoked into serial number order if not already sorted.
-        * Do this under a lock to avoid race condition.
-        */
-       if (!sk_X509_REVOKED_is_sorted(crl->crl->revoked))
-               {
-               CRYPTO_w_lock(CRYPTO_LOCK_X509_CRL);
-               sk_X509_REVOKED_sort(crl->crl->revoked);
-               CRYPTO_w_unlock(CRYPTO_LOCK_X509_CRL);
-               }
-       idx = sk_X509_REVOKED_find(crl->crl->revoked, &rtmp);
-       /* If found assume revoked: want something cleverer than
+       int ok;
+       /* Look for serial number of certificate in CRL
+        * If found assume revoked: want something cleverer than
         * this to handle entry extensions in V2 CRLs.
         */
-       if(idx >= 0)
+       if (X509_CRL_get0_by_serial(crl, NULL, X509_get_serialNumber(x)) > 0)
                {
                ctx->error = X509_V_ERR_CERT_REVOKED;
                ok = ctx->verify_cb(0, ctx);
-               if (!ok) return 0;
+               if (!ok)
+                       return 0;
                }
 
-       if (ctx->param->flags & X509_V_FLAG_IGNORE_CRITICAL)
-               return 1;
-
-       /* See if we have any critical CRL extensions: since we
-        * currently don't handle any CRL extensions the CRL must be
-        * rejected. 
-        * This code accesses the X509_CRL structure directly: applications
-        * shouldn't do this.
-        */
-
-       exts = crl->crl->extensions;
-
-       for (idx = 0; idx < sk_X509_EXTENSION_num(exts); idx++)
+       if (crl->flags & EXFLAG_CRITICAL)
                {
-               ext = sk_X509_EXTENSION_value(exts, idx);
-               if (ext->critical > 0)
-                       {
-                       ctx->error =
-                               X509_V_ERR_UNHANDLED_CRITICAL_CRL_EXTENSION;
-                       ok = ctx->verify_cb(0, ctx);
-                       if(!ok) return 0;
-                       break;
-                       }
+               if (ctx->param->flags & X509_V_FLAG_IGNORE_CRITICAL)
+                       return 1;
+               ctx->error = X509_V_ERR_UNHANDLED_CRITICAL_CRL_EXTENSION;
+               ok = ctx->verify_cb(0, ctx);
+               if(!ok)
+                       return 0;
                }
+
        return 1;
        }
 
@@ -1081,7 +1201,7 @@ int X509_cmp_time(ASN1_TIME *ctm, time_t *cmp_time)
                offset=0;
        else
                {
-               if ((*str != '+') && (str[5] != '-'))
+               if ((*str != '+') && (*str != '-'))
                        return 0;
                offset=((str[1]-'0')*10+(str[2]-'0'))*60;
                offset+=(str[3]-'0')*10+(str[4]-'0');
@@ -1430,6 +1550,16 @@ int X509_STORE_CTX_init(X509_STORE_CTX *ctx, X509_STORE *store, X509 *x509,
        else
                ctx->cert_crl = cert_crl;
 
+       if (store && store->lookup_certs)
+               ctx->lookup_certs = store->lookup_certs;
+       else
+               ctx->lookup_certs = X509_STORE_get1_certs;
+
+       if (store && store->lookup_crls)
+               ctx->lookup_crls = store->lookup_crls;
+       else
+               ctx->lookup_crls = X509_STORE_get1_crls;
+
        ctx->check_policy = check_policy;