mark all block comments that need format preserving so that

[thirdparty/openssl.git] / crypto / x509 / x509_vfy.c

/* crypto/x509/x509_vfy.c */
/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
 * All rights reserved.
 *
 * This package is an SSL implementation written
 * by Eric Young (eay@cryptsoft.com).
 * The implementation was written so as to conform with Netscapes SSL.
 * 
 * This library is free for commercial and non-commercial use as long as
 * the following conditions are aheared to.  The following conditions
 * apply to all code found in this distribution, be it the RC4, RSA,
 * lhash, DES, etc., code; not just the SSL code.  The SSL documentation
 * included with this distribution is covered by the same copyright terms
 * except that the holder is Tim Hudson (tjh@cryptsoft.com).
 * 
 * Copyright remains Eric Young's, and as such any Copyright notices in
 * the code are not to be removed.
 * If this package is used in a product, Eric Young should be given attribution
 * as the author of the parts of the library used.
 * This can be in the form of a textual message at program startup or
 * in documentation (online or textual) provided with the package.
 * 
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *    "This product includes cryptographic software written by
 *     Eric Young (eay@cryptsoft.com)"
 *    The word 'cryptographic' can be left out if the rouines from the library
 *    being used are not cryptographic related :-).
 * 4. If you include any Windows specific code (or a derivative thereof) from 
 *    the apps directory (application code) you must include an acknowledgement:
 *    "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
 * 
 * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 * 
 * The licence and distribution terms for any publically available version or
 * derivative of this code cannot be changed.  i.e. this code cannot simply be
 * copied and put under another distribution licence
 * [including the GNU Public Licence.]
 */

#include <stdio.h>
#include <time.h>
#include <errno.h>

#include "cryptlib.h"
#include <openssl/crypto.h>
#include <openssl/lhash.h>
#include <openssl/buffer.h>
#include <openssl/evp.h>
#include <openssl/asn1.h>
#include <openssl/x509.h>
#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;


static int null_callback(int ok, X509_STORE_CTX *e)
        {
        return ok;
        }

#if 0
static int x509_subject_cmp(X509 **a, X509 **b)
        {
        return X509_subject_name_cmp(*a,*b);
        }
#endif

int X509_verify_cert(X509_STORE_CTX *ctx)
        {
        X509 *x,*xtmp,*chain_ss=NULL;
        int bad_chain = 0;
        X509_VERIFY_PARAM *param = ctx->param;
        int depth,i,ok=0;
        int num;
        int (*cb)(int xok,X509_STORE_CTX *xctx);
        STACK_OF(X509) *sktmp=NULL;
        if (ctx->cert == NULL)
                {
                X509err(X509_F_X509_VERIFY_CERT,X509_R_NO_CERT_SET_FOR_US_TO_VERIFY);
                return -1;
                }

        cb=ctx->verify_cb;

        /* first we make sure the chain we are going to build is
         * present and that the first entry is in place */
        if (ctx->chain == NULL)
                {
                if (    ((ctx->chain=sk_X509_new_null()) == NULL) ||
                        (!sk_X509_push(ctx->chain,ctx->cert)))
                        {
                        X509err(X509_F_X509_VERIFY_CERT,ERR_R_MALLOC_FAILURE);
                        goto end;
                        }
                CRYPTO_add(&ctx->cert->references,1,CRYPTO_LOCK_X509);
                ctx->last_untrusted=1;
                }

        /* We use a temporary STACK so we can chop and hack at it */
        if (ctx->untrusted != NULL
            && (sktmp=sk_X509_dup(ctx->untrusted)) == NULL)
                {
                X509err(X509_F_X509_VERIFY_CERT,ERR_R_MALLOC_FAILURE);
                goto end;
                }

        num=sk_X509_num(ctx->chain);
        x=sk_X509_value(ctx->chain,num-1);
        depth=param->depth;


        for (;;)
                {
                /* If we have enough, we break */
                if (depth < num) break; /* FIXME: If this happens, we should take
                                         * note of it and, if appropriate, use the
                                         * X509_V_ERR_CERT_CHAIN_TOO_LONG error
                                         * code later.
                                         */

                /* If we are self signed, we break */
                if (ctx->check_issued(ctx, x,x)) break;

                /* If we were passed a cert chain, use it first */
                if (ctx->untrusted != NULL)
                        {
                        xtmp=find_issuer(ctx, sktmp,x);
                        if (xtmp != NULL)
                                {
                                if (!sk_X509_push(ctx->chain,xtmp))
                                        {
                                        X509err(X509_F_X509_VERIFY_CERT,ERR_R_MALLOC_FAILURE);
                                        goto end;
                                        }
                                CRYPTO_add(&xtmp->references,1,CRYPTO_LOCK_X509);
                                (void)sk_X509_delete_ptr(sktmp,xtmp);
                                ctx->last_untrusted++;
                                x=xtmp;
                                num++;
                                /* reparse the full chain for
                                 * the next one */
                                continue;
                                }
                        }
                break;
                }

        /* at this point, chain should contain a list of untrusted
         * certificates.  We now need to add at least one trusted one,
         * if possible, otherwise we complain. */

        /* Examine last certificate in chain and see if it
         * is self signed.
         */

        i=sk_X509_num(ctx->chain);
        x=sk_X509_value(ctx->chain,i-1);
        if (ctx->check_issued(ctx, x, x))
                {
                /* we have a self signed certificate */
                if (sk_X509_num(ctx->chain) == 1)
                        {
                        /* We have a single self signed certificate: see if
                         * we can find it in the store. We must have an exact
                         * match to avoid possible impersonation.
                         */
                        ok = ctx->get_issuer(&xtmp, ctx, x);
                        if ((ok <= 0) || X509_cmp(x, xtmp)) 
                                {
                                ctx->error=X509_V_ERR_DEPTH_ZERO_SELF_SIGNED_CERT;
                                ctx->current_cert=x;
                                ctx->error_depth=i-1;
                                if (ok == 1) X509_free(xtmp);
                                bad_chain = 1;
                                ok=cb(0,ctx);
                                if (!ok) goto end;
                                }
                        else 
                                {
                                /* We have a match: replace certificate with store version
                                 * so we get any trust settings.
                                 */
                                X509_free(x);
                                x = xtmp;
                                (void)sk_X509_set(ctx->chain, i - 1, x);
                                ctx->last_untrusted=0;
                                }
                        }
                else
                        {
                        /* extract and save self signed certificate for later use */
                        chain_ss=sk_X509_pop(ctx->chain);
                        ctx->last_untrusted--;
                        num--;
                        x=sk_X509_value(ctx->chain,num-1);
                        }
                }

        /* We now lookup certs from the certificate store */
        for (;;)
                {
                /* If we have enough, we break */
                if (depth < num) break;

                /* If we are self signed, we break */
                if (ctx->check_issued(ctx,x,x)) break;

                ok = ctx->get_issuer(&xtmp, ctx, x);

                if (ok < 0) return ok;
                if (ok == 0) break;

                x = xtmp;
                if (!sk_X509_push(ctx->chain,x))
                        {
                        X509_free(xtmp);
                        X509err(X509_F_X509_VERIFY_CERT,ERR_R_MALLOC_FAILURE);
                        return 0;
                        }
                num++;
                }

        /* we now have our chain, lets check it... */

        /* Is last certificate looked up self signed? */
        if (!ctx->check_issued(ctx,x,x))
                {
                if ((chain_ss == NULL) || !ctx->check_issued(ctx, x, chain_ss))
                        {
                        if (ctx->last_untrusted >= num)
                                ctx->error=X509_V_ERR_UNABLE_TO_GET_ISSUER_CERT_LOCALLY;
                        else
                                ctx->error=X509_V_ERR_UNABLE_TO_GET_ISSUER_CERT;
                        ctx->current_cert=x;
                        }
                else
                        {

                        sk_X509_push(ctx->chain,chain_ss);
                        num++;
                        ctx->last_untrusted=num;
                        ctx->current_cert=chain_ss;
                        ctx->error=X509_V_ERR_SELF_SIGNED_CERT_IN_CHAIN;
                        chain_ss=NULL;
                        }

                ctx->error_depth=num-1;
                bad_chain = 1;
                ok=cb(0,ctx);
                if (!ok) goto end;
                }

        /* We have the chain complete: now we need to check its purpose */
        ok = check_chain_extensions(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);

        if (!ok) goto end;

        /* We may as well copy down any DSA parameters that are required */
        X509_get_pubkey_parameters(NULL,ctx->chain);

        /* Check revocation status: we do this after copying parameters
         * because they may be needed for CRL signature verification.
         */

        ok = ctx->check_revocation(ctx);
        if(!ok) goto end;

        /* At this point, we have a chain and need to verify it */
        if (ctx->verify != NULL)
                ok=ctx->verify(ctx);
        else
                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);
        if(!ok) goto end;
        if (0)
                {
end:
                X509_get_pubkey_parameters(NULL,ctx->chain);
                }
        if (sktmp != NULL) sk_X509_free(sktmp);
        if (chain_ss != NULL) X509_free(chain_ss);
        return ok;
        }


/* Given a STACK_OF(X509) find the issuer of cert (if any)
 */

static X509 *find_issuer(X509_STORE_CTX *ctx, STACK_OF(X509) *sk, X509 *x)
{
        int i;
        X509 *issuer;
        for (i = 0; i < sk_X509_num(sk); i++)
                {
                issuer = sk_X509_value(sk, i);
                if (ctx->check_issued(ctx, x, issuer))
                        return issuer;
                }
        return NULL;
}

/* Given a possible certificate and issuer check them */

static int check_issued(X509_STORE_CTX *ctx, X509 *x, X509 *issuer)
{
        int ret;
        ret = X509_check_issued(issuer, x);
        if (ret == X509_V_OK)
                return 1;
        /* If we haven't asked for issuer errors don't set ctx */
        if (!(ctx->param->flags & X509_V_FLAG_CB_ISSUER_CHECK))
                return 0;

        ctx->error = ret;
        ctx->current_cert = x;
        ctx->current_issuer = issuer;
        return ctx->verify_cb(0, ctx);
        return 0;
}

/* Alternative lookup method: look from a STACK stored in other_ctx */

static int get_issuer_sk(X509 **issuer, X509_STORE_CTX *ctx, X509 *x)
{
        *issuer = find_issuer(ctx, ctx->other_ctx, x);
        if (*issuer)
                {
                CRYPTO_add(&(*issuer)->references,1,CRYPTO_LOCK_X509);
                return 1;
                }
        else
                return 0;
}
        

/* Check a certificate chains extensions for consistency
 * with the supplied purpose
 */

static int check_chain_extensions(X509_STORE_CTX *ctx)
{
#ifdef OPENSSL_NO_CHAIN_VERIFY
        return 1;
#else
        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 purpose;
        int allow_proxy_certs;
        cb=ctx->verify_cb;

        /* must_be_ca can have 1 of 3 values:
           -1: we accept both CA and non-CA certificates, to allow direct
               use of self-signed certificates (which are marked as CA).
           0:  we only accept non-CA certificates.  This is currently not
               used, but the possibility is present for future extensions.
           1:  we only accept CA certificates.  This is currently used for
               all certificates in the chain except the leaf certificate.
        */
        must_be_ca = -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++)
                {
                int ret;
                x = sk_X509_value(ctx->chain, i);
                if (!(ctx->param->flags & X509_V_FLAG_IGNORE_CRITICAL)
                        && (x->ex_flags & EXFLAG_CRITICAL))
                        {
                        ctx->error = X509_V_ERR_UNHANDLED_CRITICAL_EXTENSION;
                        ctx->error_depth = i;
                        ctx->current_cert = x;
                        ok=cb(0,ctx);
                        if (!ok) goto end;
                        }
                if (!allow_proxy_certs && (x->ex_flags & EXFLAG_PROXY))
                        {
                        ctx->error = X509_V_ERR_PROXY_CERTIFICATES_NOT_ALLOWED;
                        ctx->error_depth = i;
                        ctx->current_cert = x;
                        ok=cb(0,ctx);
                        if (!ok) goto end;
                        }
                ret = X509_check_ca(x);
                switch(must_be_ca)
                        {
                case -1:
                        if ((ctx->param->flags & X509_V_FLAG_X509_STRICT)
                                && (ret != 1) && (ret != 0))
                                {
                                ret = 0;
                                ctx->error = X509_V_ERR_INVALID_CA;
                                }
                        else
                                ret = 1;
                        break;
                case 0:
                        if (ret != 0)
                                {
                                ret = 0;
                                ctx->error = X509_V_ERR_INVALID_NON_CA;
                                }
                        else
                                ret = 1;
                        break;
                default:
                        if ((ret == 0)
                                || ((ctx->param->flags & X509_V_FLAG_X509_STRICT)
                                        && (ret != 1)))
                                {
                                ret = 0;
                                ctx->error = X509_V_ERR_INVALID_CA;
                                }
                        else
                                ret = 1;
                        break;
                        }
                if (ret == 0)
                        {
                        ctx->error_depth = i;
                        ctx->current_cert = x;
                        ok=cb(0,ctx);
                        if (!ok) goto end;
                        }
                if (ctx->param->purpose > 0)
                        {
                        ret = X509_check_purpose(x, purpose, must_be_ca > 0);
                        if ((ret == 0)
                                || ((ctx->param->flags & X509_V_FLAG_X509_STRICT)
                                        && (ret != 1)))
                                {
                                ctx->error = X509_V_ERR_INVALID_PURPOSE;
                                ctx->error_depth = i;
                                ctx->current_cert = x;
                                ok=cb(0,ctx);
                                if (!ok) goto end;
                                }
                        }
                /* 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;
                        ctx->current_cert = x;
                        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
                   CA certificate.  */
                if (x->ex_flags & EXFLAG_PROXY)
                        {
                        if (x->ex_pcpathlen != -1 && i > x->ex_pcpathlen)
                                {
                                ctx->error =
                                        X509_V_ERR_PROXY_PATH_LENGTH_EXCEEDED;
                                ctx->error_depth = i;
                                ctx->current_cert = x;
                                ok=cb(0,ctx);
                                if (!ok) goto end;
                                }
                        proxy_path_length++;
                        must_be_ca = 0;
                        }
                else
                        must_be_ca = 1;
                }
        ok = 1;
 end:
        return ok;
#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
        return 1;
#else
        int i, ok;
        X509 *x;
        int (*cb)(int xok,X509_STORE_CTX *xctx);
        cb=ctx->verify_cb;
/* For now just check the last certificate in the chain */
        i = sk_X509_num(ctx->chain) - 1;
        x = sk_X509_value(ctx->chain, i);
        ok = X509_check_trust(x, ctx->param->trust, 0);
        if (ok == X509_TRUST_TRUSTED)
                return 1;
        ctx->error_depth = i;
        ctx->current_cert = x;
        if (ok == X509_TRUST_REJECTED)
                ctx->error = X509_V_ERR_CERT_REJECTED;
        else
                ctx->error = X509_V_ERR_CERT_UNTRUSTED;
        ok = cb(0, ctx);
        return ok;
#endif
}

static int check_revocation(X509_STORE_CTX *ctx)
        {
        int i, last, ok;
        if (!(ctx->param->flags & X509_V_FLAG_CRL_CHECK))
                return 1;
        if (ctx->param->flags & X509_V_FLAG_CRL_CHECK_ALL)
                last = sk_X509_num(ctx->chain) - 1;
        else
                {
                /* If checking CRL paths this isn't the EE certificate */
                if (ctx->parent)
                        return 1;
                last = 0;
                }
        for(i = 0; i <= last; i++)
                {
                ctx->error_depth = i;
                ok = check_cert(ctx);
                if (!ok) return ok;
                }
        return 1;
        }

static int check_cert(X509_STORE_CTX *ctx)
        {
        X509_CRL *crl = NULL, *dcrl = NULL;
        X509 *x;
        int ok, cnum;
        unsigned int last_reasons;
        cnum = ctx->error_depth;
        x = sk_X509_value(ctx->chain, cnum);
        ctx->current_cert = x;
        ctx->current_issuer = NULL;
        ctx->current_crl_score = 0;
        ctx->current_reasons = 0;
        while (ctx->current_reasons != CRLDP_ALL_REASONS)
                {
                last_reasons = ctx->current_reasons;
                /* 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;
                /* If reasons not updated we wont get anywhere by
                 * another iteration, so exit loop.
                 */
                if (last_reasons == ctx->current_reasons)
                        {
                        ctx->error = X509_V_ERR_UNABLE_TO_GET_CRL;
                        ok = ctx->verify_cb(0, ctx);
                        goto err;
                        }
                }
        err:
        X509_CRL_free(crl);
        X509_CRL_free(dcrl);

        ctx->current_crl = NULL;
        return ok;

        }

/* Check CRL times against values in X509_STORE_CTX */

static int check_crl_time(X509_STORE_CTX *ctx, X509_CRL *crl, int notify)
        {
        time_t *ptime;
        int i;
        if (notify)
                ctx->current_crl = crl;
        if (ctx->param->flags & X509_V_FLAG_USE_CHECK_TIME)
                ptime = &ctx->param->check_time;
        else
                ptime = NULL;

        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 (!ctx->verify_cb(0, ctx))
                        return 0;
                }

        if (i > 0)
                {
                if (!notify)
                        return 0;
                ctx->error=X509_V_ERR_CRL_NOT_YET_VALID;
                if (!ctx->verify_cb(0, ctx))
                        return 0;
                }

        if(X509_CRL_get_nextUpdate(crl))
                {
                i=X509_cmp_time(X509_CRL_get_nextUpdate(crl), ptime);

                if (i == 0)
                        {
                        if (!notify)
                                return 0;
                        ctx->error=X509_V_ERR_ERROR_IN_CRL_NEXT_UPDATE_FIELD;
                        if (!ctx->verify_cb(0, ctx))
                                return 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 (!ctx->verify_cb(0, ctx))
                                return 0;
                        }
                }

        if (notify)
                ctx->current_crl = NULL;

        return 1;
        }

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, 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);
                reasons = *preasons;
                crl_score = get_crl_score(ctx, &crl_issuer, &reasons, crl, x);

                if (crl_score > best_score)
                        {
                        best_crl = crl;
                        best_crl_issuer = crl_issuer;
                        best_score = crl_score;
                        best_reasons = reasons;
                        }
                }

        if (best_crl)
                {
                if (*pcrl)
                        X509_CRL_free(*pcrl);
                *pcrl = best_crl;
                *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;
        }

/* 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 crl_extension_match(X509_CRL *a, X509_CRL *b, int nid)
        {
        ASN1_OCTET_STRING *exta, *extb;
        int i;
        i = X509_CRL_get_ext_by_NID(a, nid, -1);
        if (i >= 0)
                {
                /* 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, -1);

        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;

        }

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 (*pcrl_score & CRL_SCORE_ISSUER_NAME)
                        {
                        *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 <= 0)
                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;

        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)
                {
                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 */
static int check_crl(X509_STORE_CTX *ctx, X509_CRL *crl)
        {
        X509 *issuer = NULL;
        EVP_PKEY *ikey = NULL;
        int ok = 0, chnum, cnum;
        cnum = ctx->error_depth;
        chnum = sk_X509_num(ctx->chain) - 1;
        /* 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.
         */
        else if (cnum < chnum)
                issuer = sk_X509_value(ctx->chain, cnum + 1);
        else
                {
                issuer = sk_X509_value(ctx->chain, chnum);
                /* If not self signed, can't check signature */
                if(!ctx->check_issued(ctx, issuer, issuer))
                        {
                        ctx->error = X509_V_ERR_UNABLE_TO_GET_CRL_ISSUER;
                        ok = ctx->verify_cb(0, ctx);
                        if(!ok) goto err;
                        }
                }

        if(issuer)
                {
                /* Skip most tests for deltas because they have already
                 * been done
                 */
                if (!crl->base_crl_number)
                        {
                        /* 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) <= 0)
                                        {
                                        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 */
                ikey = X509_get_pubkey(issuer);

                if(!ikey)
                        {
                        ctx->error=X509_V_ERR_UNABLE_TO_DECODE_ISSUER_PUBLIC_KEY;
                        ok = ctx->verify_cb(0, ctx);
                        if (!ok) goto err;
                        }
                else
                        {
                        /* Verify CRL signature */
                        if(X509_CRL_verify(crl, ikey) <= 0)
                                {
                                ctx->error=X509_V_ERR_CRL_SIGNATURE_FAILURE;
                                ok = ctx->verify_cb(0, ctx);
                                if (!ok) goto err;
                                }
                        }
                }

        ok = 1;

        err:
        EVP_PKEY_free(ikey);
        return ok;
        }

/* Check certificate against CRL */
static int cert_crl(X509_STORE_CTX *ctx, X509_CRL *crl, X509 *x)
        {
        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 (!(ctx->param->flags & X509_V_FLAG_IGNORE_CRITICAL)
                && (crl->flags & EXFLAG_CRITICAL))
                {
                ctx->error = X509_V_ERR_UNHANDLED_CRITICAL_CRL_EXTENSION;
                ok = ctx->verify_cb(0, ctx);
                if(!ok)
                        return 0;
                }
        /* Look for serial number of certificate in CRL
         * If found make sure reason is not removeFromCRL.
         */
        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;
                }

        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)
                {
                X509err(X509_F_CHECK_POLICY,ERR_R_MALLOC_FAILURE);
                return 0;
                }
        /* Invalid or inconsistent extensions */
        if (ret == -1)
                {
                /* Locate certificates with bad extensions and notify
                 * callback.
                 */
                X509 *x;
                int i;
                for (i = 1; i < sk_X509_num(ctx->chain); i++)
                        {
                        x = sk_X509_value(ctx->chain, i);
                        if (!(x->ex_flags & EXFLAG_INVALID_POLICY))
                                continue;
                        ctx->current_cert = x;
                        ctx->error = X509_V_ERR_INVALID_POLICY_EXTENSION;
                        if(!ctx->verify_cb(0, ctx))
                                return 0;
                        }
                return 1;
                }
        if (ret == -2)
                {
                ctx->current_cert = NULL;
                ctx->error = X509_V_ERR_NO_EXPLICIT_POLICY;
                return ctx->verify_cb(0, ctx);
                }

        if (ctx->param->flags & X509_V_FLAG_NOTIFY_POLICY)
                {
                ctx->current_cert = NULL;
                ctx->error = X509_V_OK;
                if (!ctx->verify_cb(2, ctx))
                        return 0;
                }

        return 1;
        }

static int check_cert_time(X509_STORE_CTX *ctx, X509 *x)
        {
        time_t *ptime;
        int i;

        if (ctx->param->flags & X509_V_FLAG_USE_CHECK_TIME)
                ptime = &ctx->param->check_time;
        else
                ptime = NULL;

        i=X509_cmp_time(X509_get_notBefore(x), ptime);
        if (i == 0)
                {
                ctx->error=X509_V_ERR_ERROR_IN_CERT_NOT_BEFORE_FIELD;
                ctx->current_cert=x;
                if (!ctx->verify_cb(0, ctx))
                        return 0;
                }

        if (i > 0)
                {
                ctx->error=X509_V_ERR_CERT_NOT_YET_VALID;
                ctx->current_cert=x;
                if (!ctx->verify_cb(0, ctx))
                        return 0;
                }

        i=X509_cmp_time(X509_get_notAfter(x), ptime);
        if (i == 0)
                {
                ctx->error=X509_V_ERR_ERROR_IN_CERT_NOT_AFTER_FIELD;
                ctx->current_cert=x;
                if (!ctx->verify_cb(0, ctx))
                        return 0;
                }

        if (i < 0)
                {
                ctx->error=X509_V_ERR_CERT_HAS_EXPIRED;
                ctx->current_cert=x;
                if (!ctx->verify_cb(0, ctx))
                        return 0;
                }

        return 1;
        }

static int internal_verify(X509_STORE_CTX *ctx)
        {
        int ok=0,n;
        X509 *xs,*xi;
        EVP_PKEY *pkey=NULL;
        int (*cb)(int xok,X509_STORE_CTX *xctx);

        cb=ctx->verify_cb;

        n=sk_X509_num(ctx->chain);
        ctx->error_depth=n-1;
        n--;
        xi=sk_X509_value(ctx->chain,n);

        if (ctx->check_issued(ctx, xi, xi))
                xs=xi;
        else
                {
                if (n <= 0)
                        {
                        ctx->error=X509_V_ERR_UNABLE_TO_VERIFY_LEAF_SIGNATURE;
                        ctx->current_cert=xi;
                        ok=cb(0,ctx);
                        goto end;
                        }
                else
                        {
                        n--;
                        ctx->error_depth=n;
                        xs=sk_X509_value(ctx->chain,n);
                        }
                }

/*      ctx->error=0;  not needed */
        while (n >= 0)
                {
                ctx->error_depth=n;

                /* Skip signature check for self signed certificates unless
                 * explicitly asked for. It doesn't add any security and
                 * just wastes time.
                 */
                if (!xs->valid && (xs != xi || (ctx->param->flags & X509_V_FLAG_CHECK_SS_SIGNATURE)))
                        {
                        if ((pkey=X509_get_pubkey(xi)) == NULL)
                                {
                                ctx->error=X509_V_ERR_UNABLE_TO_DECODE_ISSUER_PUBLIC_KEY;
                                ctx->current_cert=xi;
                                ok=(*cb)(0,ctx);
                                if (!ok) goto end;
                                }
                        else if (X509_verify(xs,pkey) <= 0)
                                {
                                ctx->error=X509_V_ERR_CERT_SIGNATURE_FAILURE;
                                ctx->current_cert=xs;
                                ok=(*cb)(0,ctx);
                                if (!ok)
                                        {
                                        EVP_PKEY_free(pkey);
                                        goto end;
                                        }
                                }
                        EVP_PKEY_free(pkey);
                        pkey=NULL;
                        }

                xs->valid = 1;

                ok = check_cert_time(ctx, xs);
                if (!ok)
                        goto end;

                /* The last error (if any) is still in the error value */
                ctx->current_issuer=xi;
                ctx->current_cert=xs;
                ok=(*cb)(1,ctx);
                if (!ok) goto end;

                n--;
                if (n >= 0)
                        {
                        xi=xs;
                        xs=sk_X509_value(ctx->chain,n);
                        }
                }
        ok=1;
end:
        return ok;
        }

int X509_cmp_current_time(const ASN1_TIME *ctm)
{
        return X509_cmp_time(ctm, NULL);
}

int X509_cmp_time(const ASN1_TIME *ctm, time_t *cmp_time)
        {
        char *str;
        ASN1_TIME atm;
        long offset;
        char buff1[24],buff2[24],*p;
        int i,j;

        p=buff1;
        i=ctm->length;
        str=(char *)ctm->data;
        if (ctm->type == V_ASN1_UTCTIME)
                {
                if ((i < 11) || (i > 17)) return 0;
                memcpy(p,str,10);
                p+=10;
                str+=10;
                }
        else
                {
                if (i < 13) return 0;
                memcpy(p,str,12);
                p+=12;
                str+=12;
                }

        if ((*str == 'Z') || (*str == '-') || (*str == '+'))
                { *(p++)='0'; *(p++)='0'; }
        else
                { 
                *(p++)= *(str++);
                *(p++)= *(str++);
                /* Skip any fractional seconds... */
                if (*str == '.')
                        {
                        str++;
                        while ((*str >= '0') && (*str <= '9')) str++;
                        }
                
                }
        *(p++)='Z';
        *(p++)='\0';

        if (*str == 'Z')
                offset=0;
        else
                {
                if ((*str != '+') && (*str != '-'))
                        return 0;
                offset=((str[1]-'0')*10+(str[2]-'0'))*60;
                offset+=(str[3]-'0')*10+(str[4]-'0');
                if (*str == '-')
                        offset= -offset;
                }
        atm.type=ctm->type;
        atm.flags = 0;
        atm.length=sizeof(buff2);
        atm.data=(unsigned char *)buff2;

        if (X509_time_adj(&atm, offset*60, cmp_time) == NULL)
                return 0;

        if (ctm->type == V_ASN1_UTCTIME)
                {
                i=(buff1[0]-'0')*10+(buff1[1]-'0');
                if (i < 50) i+=100; /* cf. RFC 2459 */
                j=(buff2[0]-'0')*10+(buff2[1]-'0');
                if (j < 50) j+=100;

                if (i < j) return -1;
                if (i > j) return 1;
                }
        i=strcmp(buff1,buff2);
        if (i == 0) /* wait a second then return younger :-) */
                return -1;
        else
                return i;
        }

ASN1_TIME *X509_gmtime_adj(ASN1_TIME *s, long adj)
{
        return X509_time_adj(s, adj, NULL);
}

ASN1_TIME *X509_time_adj(ASN1_TIME *s, long offset_sec, time_t *in_tm)
        {
        return X509_time_adj_ex(s, 0, offset_sec, in_tm);
        }

ASN1_TIME *X509_time_adj_ex(ASN1_TIME *s,
                                int offset_day, long offset_sec, time_t *in_tm)
        {
        time_t t;

        if (in_tm) t = *in_tm;
        else time(&t);

        if (s && !(s->flags & ASN1_STRING_FLAG_MSTRING))
                {
                if (s->type == V_ASN1_UTCTIME)
                        return ASN1_UTCTIME_adj(s,t, offset_day, offset_sec);
                if (s->type == V_ASN1_GENERALIZEDTIME)
                        return ASN1_GENERALIZEDTIME_adj(s, t, offset_day,
                                                                offset_sec);
                }
        return ASN1_TIME_adj(s, t, offset_day, offset_sec);
        }

int X509_get_pubkey_parameters(EVP_PKEY *pkey, STACK_OF(X509) *chain)
        {
        EVP_PKEY *ktmp=NULL,*ktmp2;
        int i,j;

        if ((pkey != NULL) && !EVP_PKEY_missing_parameters(pkey)) return 1;

        for (i=0; i<sk_X509_num(chain); i++)
                {
                ktmp=X509_get_pubkey(sk_X509_value(chain,i));
                if (ktmp == NULL)
                        {
                        X509err(X509_F_X509_GET_PUBKEY_PARAMETERS,X509_R_UNABLE_TO_GET_CERTS_PUBLIC_KEY);
                        return 0;
                        }
                if (!EVP_PKEY_missing_parameters(ktmp))
                        break;
                else
                        {
                        EVP_PKEY_free(ktmp);
                        ktmp=NULL;
                        }
                }
        if (ktmp == NULL)
                {
                X509err(X509_F_X509_GET_PUBKEY_PARAMETERS,X509_R_UNABLE_TO_FIND_PARAMETERS_IN_CHAIN);
                return 0;
                }

        /* first, populate the other certs */
        for (j=i-1; j >= 0; j--)
                {
                ktmp2=X509_get_pubkey(sk_X509_value(chain,j));
                EVP_PKEY_copy_parameters(ktmp2,ktmp);
                EVP_PKEY_free(ktmp2);
                }
        
        if (pkey != NULL) EVP_PKEY_copy_parameters(pkey,ktmp);
        EVP_PKEY_free(ktmp);
        return 1;
        }

int X509_STORE_CTX_get_ex_new_index(long argl, void *argp, CRYPTO_EX_new *new_func,
             CRYPTO_EX_dup *dup_func, CRYPTO_EX_free *free_func)
        {
        /* This function is (usually) called only once, by
         * SSL_get_ex_data_X509_STORE_CTX_idx (ssl/ssl_cert.c). */
        return CRYPTO_get_ex_new_index(CRYPTO_EX_INDEX_X509_STORE_CTX, argl, argp,
                        new_func, dup_func, free_func);
        }

int X509_STORE_CTX_set_ex_data(X509_STORE_CTX *ctx, int idx, void *data)
        {
        return CRYPTO_set_ex_data(&ctx->ex_data,idx,data);
        }

void *X509_STORE_CTX_get_ex_data(X509_STORE_CTX *ctx, int idx)
        {
        return CRYPTO_get_ex_data(&ctx->ex_data,idx);
        }

int X509_STORE_CTX_get_error(X509_STORE_CTX *ctx)
        {
        return ctx->error;
        }

void X509_STORE_CTX_set_error(X509_STORE_CTX *ctx, int err)
        {
        ctx->error=err;
        }

int X509_STORE_CTX_get_error_depth(X509_STORE_CTX *ctx)
        {
        return ctx->error_depth;
        }

X509 *X509_STORE_CTX_get_current_cert(X509_STORE_CTX *ctx)
        {
        return ctx->current_cert;
        }

STACK_OF(X509) *X509_STORE_CTX_get_chain(X509_STORE_CTX *ctx)
        {
        return ctx->chain;
        }

STACK_OF(X509) *X509_STORE_CTX_get1_chain(X509_STORE_CTX *ctx)
        {
        int i;
        X509 *x;
        STACK_OF(X509) *chain;
        if (!ctx->chain || !(chain = sk_X509_dup(ctx->chain))) return NULL;
        for (i = 0; i < sk_X509_num(chain); i++)
                {
                x = sk_X509_value(chain, i);
                CRYPTO_add(&x->references, 1, CRYPTO_LOCK_X509);
                }
        return chain;
        }

X509 *X509_STORE_CTX_get0_current_issuer(X509_STORE_CTX *ctx)
        {
        return ctx->current_issuer;
        }

X509_CRL *X509_STORE_CTX_get0_current_crl(X509_STORE_CTX *ctx)
        {
        return ctx->current_crl;
        }

X509_STORE_CTX *X509_STORE_CTX_get0_parent_ctx(X509_STORE_CTX *ctx)
        {
        return ctx->parent;
        }

void X509_STORE_CTX_set_cert(X509_STORE_CTX *ctx, X509 *x)
        {
        ctx->cert=x;
        }

void X509_STORE_CTX_set_chain(X509_STORE_CTX *ctx, STACK_OF(X509) *sk)
        {
        ctx->untrusted=sk;
        }

void X509_STORE_CTX_set0_crls(X509_STORE_CTX *ctx, STACK_OF(X509_CRL) *sk)
        {
        ctx->crls=sk;
        }

int X509_STORE_CTX_set_purpose(X509_STORE_CTX *ctx, int purpose)
        {
        return X509_STORE_CTX_purpose_inherit(ctx, 0, purpose, 0);
        }

int X509_STORE_CTX_set_trust(X509_STORE_CTX *ctx, int trust)
        {
        return X509_STORE_CTX_purpose_inherit(ctx, 0, 0, trust);
        }

/* This function is used to set the X509_STORE_CTX purpose and trust
 * values. This is intended to be used when another structure has its
 * own trust and purpose values which (if set) will be inherited by
 * the ctx. If they aren't set then we will usually have a default
 * purpose in mind which should then be used to set the trust value.
 * An example of this is SSL use: an SSL structure will have its own
 * purpose and trust settings which the application can set: if they
 * aren't set then we use the default of SSL client/server.
 */

int X509_STORE_CTX_purpose_inherit(X509_STORE_CTX *ctx, int def_purpose,
                                int purpose, int trust)
{
        int idx;
        /* If purpose not set use default */
        if (!purpose) purpose = def_purpose;
        /* If we have a purpose then check it is valid */
        if (purpose)
                {
                X509_PURPOSE *ptmp;
                idx = X509_PURPOSE_get_by_id(purpose);
                if (idx == -1)
                        {
                        X509err(X509_F_X509_STORE_CTX_PURPOSE_INHERIT,
                                                X509_R_UNKNOWN_PURPOSE_ID);
                        return 0;
                        }
                ptmp = X509_PURPOSE_get0(idx);
                if (ptmp->trust == X509_TRUST_DEFAULT)
                        {
                        idx = X509_PURPOSE_get_by_id(def_purpose);
                        if (idx == -1)
                                {
                                X509err(X509_F_X509_STORE_CTX_PURPOSE_INHERIT,
                                                X509_R_UNKNOWN_PURPOSE_ID);
                                return 0;
                                }
                        ptmp = X509_PURPOSE_get0(idx);
                        }
                /* If trust not set then get from purpose default */
                if (!trust) trust = ptmp->trust;
                }
        if (trust)
                {
                idx = X509_TRUST_get_by_id(trust);
                if (idx == -1)
                        {
                        X509err(X509_F_X509_STORE_CTX_PURPOSE_INHERIT,
                                                X509_R_UNKNOWN_TRUST_ID);
                        return 0;
                        }
                }

        if (purpose && !ctx->param->purpose) ctx->param->purpose = purpose;
        if (trust && !ctx->param->trust) ctx->param->trust = trust;
        return 1;
}

X509_STORE_CTX *X509_STORE_CTX_new(void)
{
        X509_STORE_CTX *ctx;
        ctx = (X509_STORE_CTX *)OPENSSL_malloc(sizeof(X509_STORE_CTX));
        if (!ctx)
                {
                X509err(X509_F_X509_STORE_CTX_NEW,ERR_R_MALLOC_FAILURE);
                return NULL;
                }
        memset(ctx, 0, sizeof(X509_STORE_CTX));
        return ctx;
}

void X509_STORE_CTX_free(X509_STORE_CTX *ctx)
{
        X509_STORE_CTX_cleanup(ctx);
        OPENSSL_free(ctx);
}

int X509_STORE_CTX_init(X509_STORE_CTX *ctx, X509_STORE *store, X509 *x509,
             STACK_OF(X509) *chain)
        {
        int ret = 1;
        ctx->ctx=store;
        ctx->current_method=0;
        ctx->cert=x509;
        ctx->untrusted=chain;
        ctx->crls = NULL;
        ctx->last_untrusted=0;
        ctx->other_ctx=NULL;
        ctx->valid=0;
        ctx->chain=NULL;
        ctx->error=0;
        ctx->explicit_policy=0;
        ctx->error_depth=0;
        ctx->current_cert=NULL;
        ctx->current_issuer=NULL;
        ctx->current_crl=NULL;
        ctx->current_crl_score=0;
        ctx->current_reasons=0;
        ctx->tree = NULL;
        ctx->parent = NULL;

        ctx->param = X509_VERIFY_PARAM_new();

        if (!ctx->param)
                {
                X509err(X509_F_X509_STORE_CTX_INIT,ERR_R_MALLOC_FAILURE);
                return 0;
                }

        /* Inherit callbacks and flags from X509_STORE if not set
         * use defaults.
         */


        if (store)
                ret = X509_VERIFY_PARAM_inherit(ctx->param, store->param);
        else
                ctx->param->inh_flags |= X509_VP_FLAG_DEFAULT|X509_VP_FLAG_ONCE;

        if (store)
                {
                ctx->verify_cb = store->verify_cb;
                ctx->cleanup = store->cleanup;
                }
        else
                ctx->cleanup = 0;

        if (ret)
                ret = X509_VERIFY_PARAM_inherit(ctx->param,
                                        X509_VERIFY_PARAM_lookup("default"));

        if (ret == 0)
                {
                X509err(X509_F_X509_STORE_CTX_INIT,ERR_R_MALLOC_FAILURE);
                return 0;
                }

        if (store && store->check_issued)
                ctx->check_issued = store->check_issued;
        else
                ctx->check_issued = check_issued;

        if (store && store->get_issuer)
                ctx->get_issuer = store->get_issuer;
        else
                ctx->get_issuer = X509_STORE_CTX_get1_issuer;

        if (store && store->verify_cb)
                ctx->verify_cb = store->verify_cb;
        else
                ctx->verify_cb = null_callback;

        if (store && store->verify)
                ctx->verify = store->verify;
        else
                ctx->verify = internal_verify;

        if (store && store->check_revocation)
                ctx->check_revocation = store->check_revocation;
        else
                ctx->check_revocation = check_revocation;

        if (store && store->get_crl)
                ctx->get_crl = store->get_crl;
        else
                ctx->get_crl = NULL;

        if (store && store->check_crl)
                ctx->check_crl = store->check_crl;
        else
                ctx->check_crl = check_crl;

        if (store && store->cert_crl)
                ctx->cert_crl = store->cert_crl;
        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;


        /* This memset() can't make any sense anyway, so it's removed. As
         * X509_STORE_CTX_cleanup does a proper "free" on the ex_data, we put a
         * corresponding "new" here and remove this bogus initialisation. */
        /* memset(&(ctx->ex_data),0,sizeof(CRYPTO_EX_DATA)); */
        if(!CRYPTO_new_ex_data(CRYPTO_EX_INDEX_X509_STORE_CTX, ctx,
                                &(ctx->ex_data)))
                {
                OPENSSL_free(ctx);
                X509err(X509_F_X509_STORE_CTX_INIT,ERR_R_MALLOC_FAILURE);
                return 0;
                }
        return 1;
        }

/* Set alternative lookup method: just a STACK of trusted certificates.
 * This avoids X509_STORE nastiness where it isn't needed.
 */

void X509_STORE_CTX_trusted_stack(X509_STORE_CTX *ctx, STACK_OF(X509) *sk)
{
        ctx->other_ctx = sk;
        ctx->get_issuer = get_issuer_sk;
}

void X509_STORE_CTX_cleanup(X509_STORE_CTX *ctx)
        {
        if (ctx->cleanup) ctx->cleanup(ctx);
        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);
                ctx->chain=NULL;
                }
        CRYPTO_free_ex_data(CRYPTO_EX_INDEX_X509_STORE_CTX, ctx, &(ctx->ex_data));
        memset(&ctx->ex_data,0,sizeof(CRYPTO_EX_DATA));
        }

void X509_STORE_CTX_set_depth(X509_STORE_CTX *ctx, int depth)
        {
        X509_VERIFY_PARAM_set_depth(ctx->param, depth);
        }

void X509_STORE_CTX_set_flags(X509_STORE_CTX *ctx, unsigned long flags)
        {
        X509_VERIFY_PARAM_set_flags(ctx->param, flags);
        }

void X509_STORE_CTX_set_time(X509_STORE_CTX *ctx, unsigned long flags, time_t t)
        {
        X509_VERIFY_PARAM_set_time(ctx->param, t);
        }

void X509_STORE_CTX_set_verify_cb(X509_STORE_CTX *ctx,
                                  int (*verify_cb)(int, X509_STORE_CTX *))
        {
        ctx->verify_cb=verify_cb;
        }

X509_POLICY_TREE *X509_STORE_CTX_get0_policy_tree(X509_STORE_CTX *ctx)
        {
        return ctx->tree;
        }

int X509_STORE_CTX_get_explicit_policy(X509_STORE_CTX *ctx)
        {
        return ctx->explicit_policy;
        }

int X509_STORE_CTX_set_default(X509_STORE_CTX *ctx, const char *name)
        {
        const X509_VERIFY_PARAM *param;
        param = X509_VERIFY_PARAM_lookup(name);
        if (!param)
                return 0;
        return X509_VERIFY_PARAM_inherit(ctx->param, param);
        }

X509_VERIFY_PARAM *X509_STORE_CTX_get0_param(X509_STORE_CTX *ctx)
        {
        return ctx->param;
        }

void X509_STORE_CTX_set0_param(X509_STORE_CTX *ctx, X509_VERIFY_PARAM *param)
        {
        if (ctx->param)
                X509_VERIFY_PARAM_free(ctx->param);
        ctx->param = param;
        }

IMPLEMENT_STACK_OF(X509)
IMPLEMENT_ASN1_SET_OF(X509)

IMPLEMENT_STACK_OF(X509_NAME)

IMPLEMENT_STACK_OF(X509_ATTRIBUTE)
IMPLEMENT_ASN1_SET_OF(X509_ATTRIBUTE)