Fix build warnings.
[openssl.git] / crypto / x509 / x509_vfy.c
index 637e2b6142c57ffbd52cda0eca8bb86be19cbbdb..6f3274c3a20bb95790a88819761ba652482496d6 100644 (file)
 #include <openssl/x509v3.h>
 #include <openssl/objects.h>
 
+/* CRL score values */
+
+/* No unhandled critical extensions */
+
+#define CRL_SCORE_NOCRITICAL   0x100
+
+/* certificate is within CRL scope */
+
+#define CRL_SCORE_SCOPE                0x080
+
+/* CRL times valid */
+
+#define CRL_SCORE_TIME         0x040
+
+/* Issuer name matches certificate */
+
+#define CRL_SCORE_ISSUER_NAME  0x020
+
+/* If this score or above CRL is probably valid */
+
+#define CRL_SCORE_VALID (CRL_SCORE_NOCRITICAL|CRL_SCORE_TIME|CRL_SCORE_SCOPE)
+
+/* CRL issuer is certificate issuer */
+
+#define CRL_SCORE_ISSUER_CERT  0x018
+
+/* CRL issuer is on certificate path */
+
+#define CRL_SCORE_SAME_PATH    0x008
+
+/* CRL issuer matches CRL AKID */
+
+#define CRL_SCORE_AKID         0x004
+
+/* Have a delta CRL with valid times */
+
+#define CRL_SCORE_TIME_DELTA   0x002
+
 static int null_callback(int ok,X509_STORE_CTX *e);
 static int check_issued(X509_STORE_CTX *ctx, X509 *x, X509 *issuer);
 static X509 *find_issuer(X509_STORE_CTX *ctx, STACK_OF(X509) *sk, X509 *x);
 static int check_chain_extensions(X509_STORE_CTX *ctx);
+static int check_name_constraints(X509_STORE_CTX *ctx);
 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 get_crl_score(X509_STORE_CTX *ctx, X509 **pissuer,
+                       unsigned int *preasons,
+                       X509_CRL *crl, X509 *x);
+static int get_crl_delta(X509_STORE_CTX *ctx,
+                               X509_CRL **pcrl, X509_CRL **pdcrl, X509 *x);
+static void get_delta_sk(X509_STORE_CTX *ctx, X509_CRL **dcrl, int *pcrl_score,
+                       X509_CRL *base, STACK_OF(X509_CRL) *crls);
+static void crl_akid_check(X509_STORE_CTX *ctx, X509_CRL *crl,
+                               X509 **pissuer, int *pcrl_score);
+static int crl_crldp_check(X509 *x, X509_CRL *crl, int crl_score,
+                               unsigned int *preasons);
+static int check_crl_path(X509_STORE_CTX *ctx, X509 *x);
+static int check_crl_chain(X509_STORE_CTX *ctx,
+                       STACK_OF(X509) *cert_path,
+                       STACK_OF(X509) *crl_path);
+
 static int internal_verify(X509_STORE_CTX *ctx);
-const char *X509_version="X.509" OPENSSL_VERSION_PTEXT;
+const char X509_version[]="X.509" OPENSSL_VERSION_PTEXT;
 
 
 static int null_callback(int ok, X509_STORE_CTX *e)
@@ -164,7 +220,7 @@ int X509_verify_cert(X509_STORE_CTX *ctx)
                                        goto end;
                                        }
                                CRYPTO_add(&xtmp->references,1,CRYPTO_LOCK_X509);
-                               sk_X509_delete_ptr(sktmp,xtmp);
+                               (void)sk_X509_delete_ptr(sktmp,xtmp);
                                ctx->last_untrusted++;
                                x=xtmp;
                                num++;
@@ -214,7 +270,7 @@ int X509_verify_cert(X509_STORE_CTX *ctx)
                                 */
                                X509_free(x);
                                x = xtmp;
-                               sk_X509_set(ctx->chain, i - 1, x);
+                               (void)sk_X509_set(ctx->chain, i - 1, x);
                                ctx->last_untrusted=0;
                                }
                        }
@@ -289,6 +345,12 @@ int X509_verify_cert(X509_STORE_CTX *ctx)
 
        if (!ok) goto end;
 
+       /* Check name constraints */
+
+       ok = check_name_constraints(ctx);
+       
+       if (!ok) goto end;
+
        /* The chain extensions are OK: check trust */
 
        if (param->trust > 0) ok = check_trust(ctx);
@@ -312,6 +374,14 @@ int X509_verify_cert(X509_STORE_CTX *ctx)
                ok=internal_verify(ctx);
        if(!ok) goto end;
 
+#ifndef OPENSSL_NO_RFC3779
+       /* RFC 3779 path validation, now that CRL check has been done */
+       ok = v3_asid_validate_path(ctx);
+       if (!ok) goto end;
+       ok = v3_addr_validate_path(ctx);
+       if (!ok) goto end;
+#endif
+
        /* If we get this far evaluate policies */
        if (!bad_chain && (ctx->param->flags & X509_V_FLAG_POLICY_CHECK))
                ok = ctx->check_policy(ctx);
@@ -386,12 +456,12 @@ static int check_chain_extensions(X509_STORE_CTX *ctx)
 #ifdef OPENSSL_NO_CHAIN_VERIFY
        return 1;
 #else
-       int i, ok=0, must_be_ca;
+       int i, ok=0, must_be_ca, plen = 0;
        X509 *x;
        int (*cb)(int xok,X509_STORE_CTX *xctx);
        int proxy_path_length = 0;
-       int allow_proxy_certs =
-               !!(ctx->param->flags & X509_V_FLAG_ALLOW_PROXY_CERTS);
+       int purpose;
+       int allow_proxy_certs;
        cb=ctx->verify_cb;
 
        /* must_be_ca can have 1 of 3 values:
@@ -404,10 +474,22 @@ static int check_chain_extensions(X509_STORE_CTX *ctx)
        */
        must_be_ca = -1;
 
-       /* A hack to keep people who don't want to modify their software
-          happy */
-       if (getenv("OPENSSL_ALLOW_PROXY_CERTS"))
-               allow_proxy_certs = 1;
+       /* CRL path validation */
+       if (ctx->parent)
+               {
+               allow_proxy_certs = 0;
+               purpose = X509_PURPOSE_CRL_SIGN;
+               }
+       else
+               {
+               allow_proxy_certs =
+                       !!(ctx->param->flags & X509_V_FLAG_ALLOW_PROXY_CERTS);
+               /* A hack to keep people who don't want to modify their
+                  software happy */
+               if (getenv("OPENSSL_ALLOW_PROXY_CERTS"))
+                       allow_proxy_certs = 1;
+               purpose = ctx->param->purpose;
+               }
 
        /* Check all untrusted certificates */
        for (i = 0; i < ctx->last_untrusted; i++)
@@ -474,8 +556,7 @@ static int check_chain_extensions(X509_STORE_CTX *ctx)
                        }
                if (ctx->param->purpose > 0)
                        {
-                       ret = X509_check_purpose(x, ctx->param->purpose,
-                               must_be_ca > 0);
+                       ret = X509_check_purpose(x, purpose, must_be_ca > 0);
                        if ((ret == 0)
                                || ((ctx->param->flags & X509_V_FLAG_X509_STRICT)
                                        && (ret != 1)))
@@ -487,9 +568,10 @@ static int check_chain_extensions(X509_STORE_CTX *ctx)
                                if (!ok) goto end;
                                }
                        }
-               /* Check pathlen */
-               if ((i > 1) && (x->ex_pathlen != -1)
-                          && (i > (x->ex_pathlen + proxy_path_length + 1)))
+               /* Check pathlen if not self issued */
+               if ((i > 1) && !(x->ex_flags & EXFLAG_SI)
+                          && (x->ex_pathlen != -1)
+                          && (plen > (x->ex_pathlen + proxy_path_length + 1)))
                        {
                        ctx->error = X509_V_ERR_PATH_LENGTH_EXCEEDED;
                        ctx->error_depth = i;
@@ -497,6 +579,9 @@ static int check_chain_extensions(X509_STORE_CTX *ctx)
                        ok=cb(0,ctx);
                        if (!ok) goto end;
                        }
+               /* Increment path length if not self issued */
+               if (!(x->ex_flags & EXFLAG_SI))
+                       plen++;
                /* If this certificate is a proxy certificate, the next
                   certificate must be another proxy certificate or a EE
                   certificate.  If not, the next certificate must be a
@@ -524,6 +609,42 @@ static int check_chain_extensions(X509_STORE_CTX *ctx)
 #endif
 }
 
+static int check_name_constraints(X509_STORE_CTX *ctx)
+       {
+       X509 *x;
+       int i, j, rv;
+       /* Check name constraints for all certificates */
+       for (i = sk_X509_num(ctx->chain) - 1; i >= 0; i--)
+               {
+               x = sk_X509_value(ctx->chain, i);
+               /* Ignore self issued certs unless last in chain */
+               if (i && (x->ex_flags & EXFLAG_SI))
+                       continue;
+               /* Check against constraints for all certificates higher in
+                * chain including trust anchor. Trust anchor not strictly
+                * speaking needed but if it includes constraints it is to be
+                * assumed it expects them to be obeyed.
+                */
+               for (j = sk_X509_num(ctx->chain) - 1; j > i; j--)
+                       {
+                       NAME_CONSTRAINTS *nc = sk_X509_value(ctx->chain, j)->nc;
+                       if (nc)
+                               {
+                               rv = NAME_CONSTRAINTS_check(x, nc);
+                               if (rv != X509_V_OK)
+                                       {
+                                       ctx->error = rv;
+                                       ctx->error_depth = i;
+                                       ctx->current_cert = x;
+                                       if (!ctx->verify_cb(0,ctx))
+                                               return 0;
+                                       }
+                               }
+                       }
+               }
+       return 1;
+       }
+
 static int check_trust(X509_STORE_CTX *ctx)
 {
 #ifdef OPENSSL_NO_CHAIN_VERIFY
@@ -570,30 +691,65 @@ static int check_revocation(X509_STORE_CTX *ctx)
 
 static int check_cert(X509_STORE_CTX *ctx)
        {
-       X509_CRL *crl = NULL;
+       X509_CRL *crl = NULL, *dcrl = NULL;
        X509 *x;
        int ok, cnum;
        cnum = ctx->error_depth;
        x = sk_X509_value(ctx->chain, cnum);
        ctx->current_cert = x;
-       /* Try to retrieve relevant CRL */
-       ok = ctx->get_crl(ctx, &crl, x);
-       /* If error looking up CRL, nothing we can do except
-        * notify callback
-        */
-       if(!ok)
+       ctx->current_issuer = NULL;
+       ctx->current_reasons = 0;
+       while (ctx->current_reasons != CRLDP_ALL_REASONS)
                {
-               ctx->error = X509_V_ERR_UNABLE_TO_GET_CRL;
-               ok = ctx->verify_cb(0, ctx);
-               goto err;
+               /* Try to retrieve relevant CRL */
+               if (ctx->get_crl)
+                       ok = ctx->get_crl(ctx, &crl, x);
+               else
+                       ok = get_crl_delta(ctx, &crl, &dcrl, x);
+               /* If error looking up CRL, nothing we can do except
+                * notify callback
+                */
+               if(!ok)
+                       {
+                       ctx->error = X509_V_ERR_UNABLE_TO_GET_CRL;
+                       ok = ctx->verify_cb(0, ctx);
+                       goto err;
+                       }
+               ctx->current_crl = crl;
+               ok = ctx->check_crl(ctx, crl);
+               if (!ok)
+                       goto err;
+
+               if (dcrl)
+                       {
+                       ok = ctx->check_crl(ctx, dcrl);
+                       if (!ok)
+                               goto err;
+                       ok = ctx->cert_crl(ctx, dcrl, x);
+                       if (!ok)
+                               goto err;
+                       }
+               else
+                       ok = 1;
+
+               /* Don't look in full CRL if delta reason is removefromCRL */
+               if (ok != 2)
+                       {
+                       ok = ctx->cert_crl(ctx, crl, x);
+                       if (!ok)
+                               goto err;
+                       }
+
+               X509_CRL_free(crl);
+               X509_CRL_free(dcrl);
+               crl = NULL;
+               dcrl = NULL;
                }
-       ctx->current_crl = crl;
-       ok = ctx->check_crl(ctx, crl);
-       if (!ok) goto err;
-       ok = ctx->cert_crl(ctx, crl, x);
        err:
-       ctx->current_crl = NULL;
        X509_CRL_free(crl);
+       X509_CRL_free(dcrl);
+
+       ctx->current_crl = NULL;
        return ok;
 
        }
@@ -604,7 +760,8 @@ static int check_crl_time(X509_STORE_CTX *ctx, X509_CRL *crl, int notify)
        {
        time_t *ptime;
        int i;
-       ctx->current_crl = crl;
+       if (notify)
+               ctx->current_crl = crl;
        if (ctx->param->flags & X509_V_FLAG_USE_CHECK_TIME)
                ptime = &ctx->param->check_time;
        else
@@ -613,15 +770,19 @@ static int check_crl_time(X509_STORE_CTX *ctx, X509_CRL *crl, int notify)
        i=X509_cmp_time(X509_CRL_get_lastUpdate(crl), ptime);
        if (i == 0)
                {
+               if (!notify)
+                       return 0;
                ctx->error=X509_V_ERR_ERROR_IN_CRL_LAST_UPDATE_FIELD;
-               if (!notify || !ctx->verify_cb(0, ctx))
+               if (!ctx->verify_cb(0, ctx))
                        return 0;
                }
 
        if (i > 0)
                {
+               if (!notify)
+                       return 0;
                ctx->error=X509_V_ERR_CRL_NOT_YET_VALID;
-               if (!notify || !ctx->verify_cb(0, ctx))
+               if (!ctx->verify_cb(0, ctx))
                        return 0;
                }
 
@@ -631,92 +792,545 @@ static int check_crl_time(X509_STORE_CTX *ctx, X509_CRL *crl, int notify)
 
                if (i == 0)
                        {
+                       if (!notify)
+                               return 0;
                        ctx->error=X509_V_ERR_ERROR_IN_CRL_NEXT_UPDATE_FIELD;
-                       if (!notify || !ctx->verify_cb(0, ctx))
+                       if (!ctx->verify_cb(0, ctx))
                                return 0;
                        }
-
-               if (i < 0)
+               /* Ignore expiry of base CRL is delta is valid */
+               if ((i < 0) && !(ctx->current_crl_score & CRL_SCORE_TIME_DELTA))
                        {
+                       if (!notify)
+                               return 0;
                        ctx->error=X509_V_ERR_CRL_HAS_EXPIRED;
-                       if (!notify || !ctx->verify_cb(0, ctx))
+                       if (!ctx->verify_cb(0, ctx))
                                return 0;
                        }
                }
 
-       ctx->current_crl = NULL;
+       if (notify)
+               ctx->current_crl = NULL;
 
        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.
- */
-
-static int get_crl_sk(X509_STORE_CTX *ctx, X509_CRL **pcrl,
-                       X509_NAME *nm, STACK_OF(X509_CRL) *crls)
+static int get_crl_sk(X509_STORE_CTX *ctx, X509_CRL **pcrl, X509_CRL **pdcrl,
+                       X509 **pissuer, int *pscore, unsigned int *preasons,
+                       STACK_OF(X509_CRL) *crls)
        {
-       int i;
+       int i, crl_score, best_score = *pscore;
+       unsigned int reasons, best_reasons = 0;
+       X509 *x = ctx->current_cert;
        X509_CRL *crl, *best_crl = NULL;
+       X509 *crl_issuer = NULL, *best_crl_issuer = NULL;
+
        for (i = 0; i < sk_X509_CRL_num(crls); i++)
                {
                crl = sk_X509_CRL_value(crls, i);
-               if (X509_NAME_cmp(nm, X509_CRL_get_issuer(crl)))
-                       continue;
-               if (check_crl_time(ctx, crl, 0))
+               reasons = *preasons;
+               crl_score = get_crl_score(ctx, &crl_issuer, &reasons, crl, x);
+
+               if (crl_score > best_score)
                        {
-                       *pcrl = crl;
-                       CRYPTO_add(&crl->references, 1, CRYPTO_LOCK_X509);
-                       return 1;
+                       best_crl = crl;
+                       best_crl_issuer = crl_issuer;
+                       best_score = crl_score;
+                       best_reasons = reasons;
                        }
-               best_crl = crl;
                }
+
        if (best_crl)
                {
+               if (*pcrl)
+                       X509_CRL_free(*pcrl);
                *pcrl = best_crl;
-               CRYPTO_add(&best_crl->references, 1, CRYPTO_LOCK_X509);
+               *pissuer = best_crl_issuer;
+               *pscore = best_score;
+               *preasons = best_reasons;
+               CRYPTO_add(&best_crl->references, 1, CRYPTO_LOCK_X509_CRL);
+               if (*pdcrl)
+                       {
+                       X509_CRL_free(*pdcrl);
+                       *pdcrl = NULL;
+                       }
+               get_delta_sk(ctx, pdcrl, pscore, best_crl, crls);
                }
-               
+
+       if (best_score >= CRL_SCORE_VALID)
+               return 1;
+
        return 0;
        }
 
-/* Retrieve CRL corresponding to certificate: currently just a
- * subject lookup: maybe use AKID later...
+/* Compare two CRL extensions for delta checking purposes. They should be
+ * both present or both absent. If both present all fields must be identical.
  */
-static int get_crl(X509_STORE_CTX *ctx, X509_CRL **pcrl, X509 *x)
+
+static int crl_extension_match(X509_CRL *a, X509_CRL *b, int nid)
        {
-       int ok;
-       X509_CRL *crl = NULL;
-       X509_OBJECT xobj;
-       X509_NAME *nm;
-       nm = X509_get_issuer_name(x);
-       ok = get_crl_sk(ctx, &crl, nm, ctx->crls);
-       if (ok)
+       ASN1_OCTET_STRING *exta, *extb;
+       int i;
+       i = X509_CRL_get_ext_by_NID(a, nid, 0);
+       if (i >= 0)
                {
-               *pcrl = crl;
+               /* Can't have multiple occurrences */
+               if (X509_CRL_get_ext_by_NID(a, nid, i) != -1)
+                       return 0;
+               exta = X509_EXTENSION_get_data(X509_CRL_get_ext(a, i));
+               }
+       else
+               exta = NULL;
+
+       i = X509_CRL_get_ext_by_NID(b, nid, 0);
+
+       if (i >= 0)
+               {
+
+               if (X509_CRL_get_ext_by_NID(b, nid, i) != -1)
+                       return 0;
+               extb = X509_EXTENSION_get_data(X509_CRL_get_ext(b, i));
+               }
+       else
+               extb = NULL;
+
+       if (!exta && !extb)
                return 1;
+
+       if (!exta || !extb)
+               return 0;
+
+
+       if (ASN1_OCTET_STRING_cmp(exta, extb))
+               return 0;
+
+       return 1;
+       }
+
+/* See if a base and delta are compatible */
+
+static int check_delta_base(X509_CRL *delta, X509_CRL *base)
+       {
+       /* Delta CRL must be a delta */
+       if (!delta->base_crl_number)
+                       return 0;
+       /* Base must have a CRL number */
+       if (!base->crl_number)
+                       return 0;
+       /* Issuer names must match */
+       if (X509_NAME_cmp(X509_CRL_get_issuer(base),
+                               X509_CRL_get_issuer(delta)))
+               return 0;
+       /* AKID and IDP must match */
+       if (!crl_extension_match(delta, base, NID_authority_key_identifier))
+                       return 0;
+       if (!crl_extension_match(delta, base, NID_issuing_distribution_point))
+                       return 0;
+       /* Delta CRL base number must not exceed Full CRL number. */
+       if (ASN1_INTEGER_cmp(delta->base_crl_number, base->crl_number) > 0)
+                       return 0;
+       /* Delta CRL number must exceed full CRL number */
+       if (ASN1_INTEGER_cmp(delta->crl_number, base->crl_number) > 0)
+                       return 1;
+       return 0;
+       }
+
+/* For a given base CRL find a delta... maybe extend to delta scoring
+ * or retrieve a chain of deltas...
+ */
+
+static void get_delta_sk(X509_STORE_CTX *ctx, X509_CRL **dcrl, int *pscore,
+                       X509_CRL *base, STACK_OF(X509_CRL) *crls)
+       {
+       X509_CRL *delta;
+       int i;
+       if (!(ctx->param->flags & X509_V_FLAG_USE_DELTAS))
+               return;
+       if (!((ctx->current_cert->ex_flags | base->flags) & EXFLAG_FRESHEST))
+               return;
+       for (i = 0; i < sk_X509_CRL_num(crls); i++)
+               {
+               delta = sk_X509_CRL_value(crls, i);
+               if (check_delta_base(delta, base))
+                       {
+                       if (check_crl_time(ctx, delta, 0))
+                               *pscore |= CRL_SCORE_TIME_DELTA;
+                       CRYPTO_add(&delta->references, 1, CRYPTO_LOCK_X509_CRL);
+                       *dcrl = delta;
+                       return;
+                       }
+               }
+       *dcrl = NULL;
+       }
+
+/* For a given CRL return how suitable it is for the supplied certificate 'x'.
+ * The return value is a mask of several criteria.
+ * If the issuer is not the certificate issuer this is returned in *pissuer.
+ * The reasons mask is also used to determine if the CRL is suitable: if
+ * no new reasons the CRL is rejected, otherwise reasons is updated.
+ */
+
+static int get_crl_score(X509_STORE_CTX *ctx, X509 **pissuer,
+                       unsigned int *preasons,
+                       X509_CRL *crl, X509 *x)
+       {
+
+       int crl_score = 0;
+       unsigned int tmp_reasons = *preasons, crl_reasons;
+
+       /* First see if we can reject CRL straight away */
+
+       /* Invalid IDP cannot be processed */
+       if (crl->idp_flags & IDP_INVALID)
+               return 0;
+       /* Reason codes or indirect CRLs need extended CRL support */
+       if (!(ctx->param->flags & X509_V_FLAG_EXTENDED_CRL_SUPPORT))
+               {
+               if (crl->idp_flags & (IDP_INDIRECT | IDP_REASONS))
+                       return 0;
+               }
+       else if (crl->idp_flags & IDP_REASONS)
+               {
+               /* If no new reasons reject */
+               if (!(crl->idp_reasons & ~tmp_reasons))
+                       return 0;
+               }
+       /* Don't process deltas at this stage */
+       else if (crl->base_crl_number)
+               return 0;
+       /* If issuer name doesn't match certificate need indirect CRL */
+       if (X509_NAME_cmp(X509_get_issuer_name(x), X509_CRL_get_issuer(crl)))
+               {
+               if (!(crl->idp_flags & IDP_INDIRECT))
+                       return 0;
                }
+       else
+               crl_score |= CRL_SCORE_ISSUER_NAME;
+
+       if (!(crl->flags & EXFLAG_CRITICAL))
+               crl_score |= CRL_SCORE_NOCRITICAL;
+
+       /* Check expiry */
+       if (check_crl_time(ctx, crl, 0))
+               crl_score |= CRL_SCORE_TIME;
+
+       /* Check authority key ID and locate certificate issuer */
+       crl_akid_check(ctx, crl, pissuer, &crl_score);
+
+       /* If we can't locate certificate issuer at this point forget it */
+
+       if (!(crl_score & CRL_SCORE_AKID))
+               return 0;
+
+       /* Check cert for matching CRL distribution points */
+
+       if (crl_crldp_check(x, crl, crl_score, &crl_reasons))
+               {
+               /* If no new reasons reject */
+               if (!(crl_reasons & ~tmp_reasons))
+                       return 0;
+               tmp_reasons |= crl_reasons;
+               crl_score |= CRL_SCORE_SCOPE;
+               }
+
+       *preasons = tmp_reasons;
+
+       return crl_score;
 
-       ok = X509_STORE_get_by_subject(ctx, X509_LU_CRL, nm, &xobj);
+       }
 
-       if (!ok)
+static void crl_akid_check(X509_STORE_CTX *ctx, X509_CRL *crl,
+                               X509 **pissuer, int *pcrl_score)
+       {
+       X509 *crl_issuer = NULL;
+       X509_NAME *cnm = X509_CRL_get_issuer(crl);
+       int cidx = ctx->error_depth;
+       int i;
+
+       if (cidx != sk_X509_num(ctx->chain) - 1)
+               cidx++;
+
+       crl_issuer = sk_X509_value(ctx->chain, cidx);
+
+       if (X509_check_akid(crl_issuer, crl->akid) == X509_V_OK)
                {
-               /* If we got a near match from get_crl_sk use that */
-               if (crl)
+               if (*pcrl_score & CRL_SCORE_ISSUER_NAME)
                        {
-                       *pcrl = crl;
-                       return 1;
+                       *pcrl_score |= CRL_SCORE_AKID|CRL_SCORE_ISSUER_CERT;
+                       *pissuer = crl_issuer;
+                       return;
+                       }
+               }
+
+       for (cidx++; cidx < sk_X509_num(ctx->chain); cidx++)
+               {
+               crl_issuer = sk_X509_value(ctx->chain, cidx);
+               if (X509_NAME_cmp(X509_get_subject_name(crl_issuer), cnm))
+                       continue;
+               if (X509_check_akid(crl_issuer, crl->akid) == X509_V_OK)
+                       {
+                       *pcrl_score |= CRL_SCORE_AKID|CRL_SCORE_SAME_PATH;
+                       *pissuer = crl_issuer;
+                       return;
                        }
+               }
+
+       /* Anything else needs extended CRL support */
+
+       if (!(ctx->param->flags & X509_V_FLAG_EXTENDED_CRL_SUPPORT))
+               return;
+
+       /* Otherwise the CRL issuer is not on the path. Look for it in the
+        * set of untrusted certificates.
+        */
+       for (i = 0; i < sk_X509_num(ctx->untrusted); i++)
+               {
+               crl_issuer = sk_X509_value(ctx->untrusted, i);
+               if (X509_NAME_cmp(X509_get_subject_name(crl_issuer), cnm))
+                       continue;
+               if (X509_check_akid(crl_issuer, crl->akid) == X509_V_OK)
+                       {
+                       *pissuer = crl_issuer;
+                       *pcrl_score |= CRL_SCORE_AKID;
+                       return;
+                       }
+               }
+       }
+
+/* Check the path of a CRL issuer certificate. This creates a new
+ * X509_STORE_CTX and populates it with most of the parameters from the
+ * parent. This could be optimised somewhat since a lot of path checking
+ * will be duplicated by the parent, but this will rarely be used in 
+ * practice.
+ */
+
+static int check_crl_path(X509_STORE_CTX *ctx, X509 *x)
+       {
+       X509_STORE_CTX crl_ctx;
+       int ret;
+       /* Don't allow recursive CRL path validation */
+       if (ctx->parent)
                return 0;
+       if (!X509_STORE_CTX_init(&crl_ctx, ctx->ctx, x, ctx->untrusted))
+               return -1;
+
+       crl_ctx.crls = ctx->crls;
+       /* Copy verify params across */
+       X509_STORE_CTX_set0_param(&crl_ctx, ctx->param);
+
+       crl_ctx.parent = ctx;
+       crl_ctx.verify_cb = ctx->verify_cb;
+
+       /* Verify CRL issuer */
+       ret = X509_verify_cert(&crl_ctx);
+
+       if (!ret)
+               goto err;
+
+       /* Check chain is acceptable */
+
+       ret = check_crl_chain(ctx, ctx->chain, crl_ctx.chain);
+       err:
+       X509_STORE_CTX_cleanup(&crl_ctx);
+       return ret;
+       }
+
+/* RFC3280 says nothing about the relationship between CRL path
+ * and certificate path, which could lead to situations where a
+ * certificate could be revoked or validated by a CA not authorised
+ * to do so. RFC5280 is more strict and states that the two paths must
+ * end in the same trust anchor, though some discussions remain...
+ * until this is resolved we use the RFC5280 version
+ */
+
+static int check_crl_chain(X509_STORE_CTX *ctx,
+                       STACK_OF(X509) *cert_path,
+                       STACK_OF(X509) *crl_path)
+       {
+       X509 *cert_ta, *crl_ta;
+       cert_ta = sk_X509_value(cert_path, sk_X509_num(cert_path) - 1);
+       crl_ta = sk_X509_value(crl_path, sk_X509_num(crl_path) - 1);
+       if (!X509_cmp(cert_ta, crl_ta))
+               return 1;
+       return 0;
+       }
+
+/* Check for match between two dist point names: three separate cases.
+ * 1. Both are relative names and compare X509_NAME types.
+ * 2. One full, one relative. Compare X509_NAME to GENERAL_NAMES.
+ * 3. Both are full names and compare two GENERAL_NAMES.
+ * 4. One is NULL: automatic match.
+ */
+
+
+static int idp_check_dp(DIST_POINT_NAME *a, DIST_POINT_NAME *b)
+       {
+       X509_NAME *nm = NULL;
+       GENERAL_NAMES *gens = NULL;
+       GENERAL_NAME *gena, *genb;
+       int i, j;
+       if (!a || !b)
+               return 1;
+       if (a->type == 1)
+               {
+               if (!a->dpname)
+                       return 0;
+               /* Case 1: two X509_NAME */
+               if (b->type == 1)
+                       {
+                       if (!b->dpname)
+                               return 0;
+                       if (!X509_NAME_cmp(a->dpname, b->dpname))
+                               return 1;
+                       else
+                               return 0;
+                       }
+               /* Case 2: set name and GENERAL_NAMES appropriately */
+               nm = a->dpname;
+               gens = b->name.fullname;
+               }
+       else if (b->type == 1)
+               {
+               if (!b->dpname)
+                       return 0;
+               /* Case 2: set name and GENERAL_NAMES appropriately */
+               gens = a->name.fullname;
+               nm = b->dpname;
+               }
+
+       /* Handle case 2 with one GENERAL_NAMES and one X509_NAME */
+       if (nm)
+               {
+               for (i = 0; i < sk_GENERAL_NAME_num(gens); i++)
+                       {
+                       gena = sk_GENERAL_NAME_value(gens, i);  
+                       if (gena->type != GEN_DIRNAME)
+                               continue;
+                       if (!X509_NAME_cmp(nm, gena->d.directoryName))
+                               return 1;
+                       }
+               return 0;
+               }
+
+       /* Else case 3: two GENERAL_NAMES */
+
+       for (i = 0; i < sk_GENERAL_NAME_num(a->name.fullname); i++)
+               {
+               gena = sk_GENERAL_NAME_value(a->name.fullname, i);
+               for (j = 0; j < sk_GENERAL_NAME_num(b->name.fullname); j++)
+                       {
+                       genb = sk_GENERAL_NAME_value(b->name.fullname, j);
+                       if (!GENERAL_NAME_cmp(gena, genb))
+                               return 1;
+                       }
+               }
+
+       return 0;
+
+       }
+
+static int crldp_check_crlissuer(DIST_POINT *dp, X509_CRL *crl, int crl_score)
+       {
+       int i;
+       X509_NAME *nm = X509_CRL_get_issuer(crl);
+       /* If no CRLissuer return is successful iff don't need a match */
+       if (!dp->CRLissuer)
+               return !!(crl_score & CRL_SCORE_ISSUER_NAME);
+       for (i = 0; i < sk_GENERAL_NAME_num(dp->CRLissuer); i++)
+               {
+               GENERAL_NAME *gen = sk_GENERAL_NAME_value(dp->CRLissuer, i);
+               if (gen->type != GEN_DIRNAME)
+                       continue;
+               if (!X509_NAME_cmp(gen->d.directoryName, nm))
+                       return 1;
+               }
+       return 0;
+       }
+
+/* Check CRLDP and IDP */
+
+static int crl_crldp_check(X509 *x, X509_CRL *crl, int crl_score,
+                               unsigned int *preasons)
+       {
+       int i;
+       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;
+               }
+       *preasons = crl->idp_reasons;
+       for (i = 0; i < sk_DIST_POINT_num(x->crldp); i++)
+               {
+               DIST_POINT *dp = sk_DIST_POINT_value(x->crldp, i);
+               if (crldp_check_crlissuer(dp, crl, crl_score))
+                       {
+                       if (!crl->idp ||
+                            idp_check_dp(dp->distpoint, crl->idp->distpoint))
+                               {
+                               *preasons &= dp->dp_reasons;
+                               return 1;
+                               }
+                       }
                }
+       if ((!crl->idp || !crl->idp->distpoint) && (crl_score & CRL_SCORE_ISSUER_NAME))
+               return 1;
+       return 0;
+       }
+
+/* Retrieve CRL corresponding to current certificate.
+ * If deltas enabled try to find a delta CRL too
+ */
+       
+static int get_crl_delta(X509_STORE_CTX *ctx,
+                               X509_CRL **pcrl, X509_CRL **pdcrl, X509 *x)
+       {
+       int ok;
+       X509 *issuer = NULL;
+       int crl_score = 0;
+       unsigned int reasons;
+       X509_CRL *crl = NULL, *dcrl = NULL;
+       STACK_OF(X509_CRL) *skcrl;
+       X509_NAME *nm = X509_get_issuer_name(x);
+       reasons = ctx->current_reasons;
+       ok = get_crl_sk(ctx, &crl, &dcrl, 
+                               &issuer, &crl_score, &reasons, ctx->crls);
+
+       if (ok)
+               goto done;
+
+       /* Lookup CRLs from store */
+
+       skcrl = ctx->lookup_crls(ctx, nm);
+
+       /* If no CRLs found and a near match from get_crl_sk use that */
+       if (!skcrl && crl)
+               goto done;
 
-       *pcrl = xobj.data.crl;
+       get_crl_sk(ctx, &crl, &dcrl, &issuer, &crl_score, &reasons, skcrl);
+
+       sk_X509_CRL_pop_free(skcrl, X509_CRL_free);
+
+       done:
+
+       /* If we got any kind of CRL use it and return success */
        if (crl)
-               X509_CRL_free(crl);
-       return 1;
+               {
+               ctx->current_issuer = issuer;
+               ctx->current_crl_score = crl_score;
+               ctx->current_reasons = reasons;
+               *pcrl = crl;
+               *pdcrl = dcrl;
+               return 1;
+               }
+
+       return 0;
        }
 
 /* Check CRL validity */
@@ -727,10 +1341,14 @@ static int check_crl(X509_STORE_CTX *ctx, X509_CRL *crl)
        int ok = 0, chnum, cnum;
        cnum = ctx->error_depth;
        chnum = sk_X509_num(ctx->chain) - 1;
-       /* Find CRL issuer: if not last certificate then issuer
+       /* if we have an alternative CRL issuer cert use that */
+       if (ctx->current_issuer)
+               issuer = ctx->current_issuer;
+
+       /* Else find CRL issuer: if not last certificate then issuer
         * is next certificate in chain.
         */
-       if(cnum < chnum)
+       else if (cnum < chnum)
                issuer = sk_X509_value(ctx->chain, cnum + 1);
        else
                {
@@ -746,13 +1364,52 @@ static int check_crl(X509_STORE_CTX *ctx, X509_CRL *crl)
 
        if(issuer)
                {
-               /* Check for cRLSign bit if keyUsage present */
-               if ((issuer->ex_flags & EXFLAG_KUSAGE) &&
-                       !(issuer->ex_kusage & KU_CRL_SIGN))
+               /* Skip most tests for deltas because they have already
+                * been done
+                */
+               if (!crl->base_crl_number)
                        {
-                       ctx->error = X509_V_ERR_KEYUSAGE_NO_CRL_SIGN;
-                       ok = ctx->verify_cb(0, ctx);
-                       if(!ok) goto err;
+                       /* Check for cRLSign bit if keyUsage present */
+                       if ((issuer->ex_flags & EXFLAG_KUSAGE) &&
+                               !(issuer->ex_kusage & KU_CRL_SIGN))
+                               {
+                               ctx->error = X509_V_ERR_KEYUSAGE_NO_CRL_SIGN;
+                               ok = ctx->verify_cb(0, ctx);
+                               if(!ok) goto err;
+                               }
+
+                       if (!(ctx->current_crl_score & CRL_SCORE_SCOPE))
+                               {
+                               ctx->error = X509_V_ERR_DIFFERENT_CRL_SCOPE;
+                               ok = ctx->verify_cb(0, ctx);
+                               if(!ok) goto err;
+                               }
+
+                       if (!(ctx->current_crl_score & CRL_SCORE_SAME_PATH))
+                               {
+                               if (!check_crl_path(ctx, ctx->current_issuer))
+                                       {
+                                       ctx->error = X509_V_ERR_CRL_PATH_VALIDATION_ERROR;
+                                       ok = ctx->verify_cb(0, ctx);
+                                       if(!ok) goto err;
+                                       }
+                               }
+
+                       if (crl->idp_flags & IDP_INVALID)
+                               {
+                               ctx->error = X509_V_ERR_INVALID_EXTENSION;
+                               ok = ctx->verify_cb(0, ctx);
+                               if(!ok) goto err;
+                               }
+
+
+                       }
+
+               if (!(ctx->current_crl_score & CRL_SCORE_TIME))
+                       {
+                       ok = check_crl_time(ctx, crl, 1);
+                       if (!ok)
+                               goto err;
                        }
 
                /* Attempt to get issuer certificate public key */
@@ -776,9 +1433,6 @@ static int check_crl(X509_STORE_CTX *ctx, X509_CRL *crl)
                        }
                }
 
-       if (!check_crl_time(ctx, crl, 1))
-               goto err;
-
        ok = 1;
 
        err:
@@ -789,62 +1443,43 @@ 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))
+       int ok;
+       X509_REVOKED *rev;
+       /* The rules changed for this... previously if a CRL contained
+        * unhandled critical extensions it could still be used to indicate
+        * a certificate was revoked. This has since been changed since 
+        * critical extension can change the meaning of CRL entries.
+        */
+       if (crl->flags & EXFLAG_CRITICAL)
                {
-               CRYPTO_w_lock(CRYPTO_LOCK_X509_CRL);
-               sk_X509_REVOKED_sort(crl->crl->revoked);
-               CRYPTO_w_unlock(CRYPTO_LOCK_X509_CRL);
+               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;
                }
-       idx = sk_X509_REVOKED_find(crl->crl->revoked, &rtmp);
-       /* If found assume revoked: want something cleverer than
-        * this to handle entry extensions in V2 CRLs.
+       /* Look for serial number of certificate in CRL
+        * If found make sure reason is not removeFromCRL.
         */
-       if(idx >= 0)
+       if (X509_CRL_get0_by_cert(crl, &rev, x))
                {
+               if (rev->reason == CRL_REASON_REMOVE_FROM_CRL)
+                       return 2;
                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++)
-               {
-               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;
-                       }
-               }
        return 1;
        }
 
 static int check_policy(X509_STORE_CTX *ctx)
        {
        int ret;
+       if (ctx->parent)
+               return 1;
        ret = X509_policy_check(&ctx->tree, &ctx->explicit_policy, ctx->chain,
                                ctx->param->policies, ctx->param->flags);
        if (ret == 0)
@@ -867,7 +1502,8 @@ static int check_policy(X509_STORE_CTX *ctx)
                                continue;
                        ctx->current_cert = x;
                        ctx->error = X509_V_ERR_INVALID_POLICY_EXTENSION;
-                       ret = ctx->verify_cb(0, ctx);
+                       if(!ctx->verify_cb(0, ctx))
+                               return 0;
                        }
                return 1;
                }
@@ -1006,7 +1642,8 @@ static int internal_verify(X509_STORE_CTX *ctx)
 
                xs->valid = 1;
 
-               if (!check_cert_time(ctx, xs))
+               ok = check_cert_time(ctx, xs);
+               if (!ok)
                        goto end;
 
                /* The last error (if any) is still in the error value */
@@ -1027,12 +1664,12 @@ end:
        return ok;
        }
 
-int X509_cmp_current_time(ASN1_TIME *ctm)
+int X509_cmp_current_time(const ASN1_TIME *ctm)
 {
        return X509_cmp_time(ctm, NULL);
 }
 
-int X509_cmp_time(ASN1_TIME *ctm, time_t *cmp_time)
+int X509_cmp_time(const ASN1_TIME *ctm, time_t *cmp_time)
        {
        char *str;
        ASN1_TIME atm;
@@ -1079,7 +1716,7 @@ 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');
@@ -1351,6 +1988,7 @@ int X509_STORE_CTX_init(X509_STORE_CTX *ctx, X509_STORE *store, X509 *x509,
        ctx->current_cert=NULL;
        ctx->current_issuer=NULL;
        ctx->tree = NULL;
+       ctx->parent = NULL;
 
        ctx->param = X509_VERIFY_PARAM_new();
 
@@ -1416,7 +2054,7 @@ int X509_STORE_CTX_init(X509_STORE_CTX *ctx, X509_STORE *store, X509 *x509,
        if (store && store->get_crl)
                ctx->get_crl = store->get_crl;
        else
-               ctx->get_crl = get_crl;
+               ctx->get_crl = NULL;
 
        if (store && store->check_crl)
                ctx->check_crl = store->check_crl;
@@ -1428,6 +2066,16 @@ 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;
 
 
@@ -1458,9 +2106,17 @@ void X509_STORE_CTX_trusted_stack(X509_STORE_CTX *ctx, STACK_OF(X509) *sk)
 void X509_STORE_CTX_cleanup(X509_STORE_CTX *ctx)
        {
        if (ctx->cleanup) ctx->cleanup(ctx);
-       X509_VERIFY_PARAM_free(ctx->param);
-       if (ctx->tree)
+       if (ctx->param != NULL)
+               {
+               if (ctx->parent == NULL)
+                       X509_VERIFY_PARAM_free(ctx->param);
+               ctx->param=NULL;
+               }
+       if (ctx->tree != NULL)
+               {
                X509_policy_tree_free(ctx->tree);
+               ctx->tree=NULL;
+               }
        if (ctx->chain != NULL)
                {
                sk_X509_pop_free(ctx->chain,X509_free);