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Member "openssl-1.1.1g/crypto/x509/x509_vfy.c" (21 Apr 2020, 104134 Bytes) of package /linux/misc/openssl-1.1.1g.tar.gz:


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    1 /*
    2  * Copyright 1995-2020 The OpenSSL Project Authors. All Rights Reserved.
    3  *
    4  * Licensed under the OpenSSL license (the "License").  You may not use
    5  * this file except in compliance with the License.  You can obtain a copy
    6  * in the file LICENSE in the source distribution or at
    7  * https://www.openssl.org/source/license.html
    8  */
    9 
   10 #include <stdio.h>
   11 #include <time.h>
   12 #include <errno.h>
   13 #include <limits.h>
   14 
   15 #include "crypto/ctype.h"
   16 #include "internal/cryptlib.h"
   17 #include <openssl/crypto.h>
   18 #include <openssl/buffer.h>
   19 #include <openssl/evp.h>
   20 #include <openssl/asn1.h>
   21 #include <openssl/x509.h>
   22 #include <openssl/x509v3.h>
   23 #include <openssl/objects.h>
   24 #include "internal/dane.h"
   25 #include "crypto/x509.h"
   26 #include "x509_local.h"
   27 
   28 /* CRL score values */
   29 
   30 /* No unhandled critical extensions */
   31 
   32 #define CRL_SCORE_NOCRITICAL    0x100
   33 
   34 /* certificate is within CRL scope */
   35 
   36 #define CRL_SCORE_SCOPE         0x080
   37 
   38 /* CRL times valid */
   39 
   40 #define CRL_SCORE_TIME          0x040
   41 
   42 /* Issuer name matches certificate */
   43 
   44 #define CRL_SCORE_ISSUER_NAME   0x020
   45 
   46 /* If this score or above CRL is probably valid */
   47 
   48 #define CRL_SCORE_VALID (CRL_SCORE_NOCRITICAL|CRL_SCORE_TIME|CRL_SCORE_SCOPE)
   49 
   50 /* CRL issuer is certificate issuer */
   51 
   52 #define CRL_SCORE_ISSUER_CERT   0x018
   53 
   54 /* CRL issuer is on certificate path */
   55 
   56 #define CRL_SCORE_SAME_PATH     0x008
   57 
   58 /* CRL issuer matches CRL AKID */
   59 
   60 #define CRL_SCORE_AKID          0x004
   61 
   62 /* Have a delta CRL with valid times */
   63 
   64 #define CRL_SCORE_TIME_DELTA    0x002
   65 
   66 static int build_chain(X509_STORE_CTX *ctx);
   67 static int verify_chain(X509_STORE_CTX *ctx);
   68 static int dane_verify(X509_STORE_CTX *ctx);
   69 static int null_callback(int ok, X509_STORE_CTX *e);
   70 static int check_issued(X509_STORE_CTX *ctx, X509 *x, X509 *issuer);
   71 static X509 *find_issuer(X509_STORE_CTX *ctx, STACK_OF(X509) *sk, X509 *x);
   72 static int check_chain_extensions(X509_STORE_CTX *ctx);
   73 static int check_name_constraints(X509_STORE_CTX *ctx);
   74 static int check_id(X509_STORE_CTX *ctx);
   75 static int check_trust(X509_STORE_CTX *ctx, int num_untrusted);
   76 static int check_revocation(X509_STORE_CTX *ctx);
   77 static int check_cert(X509_STORE_CTX *ctx);
   78 static int check_policy(X509_STORE_CTX *ctx);
   79 static int get_issuer_sk(X509 **issuer, X509_STORE_CTX *ctx, X509 *x);
   80 static int check_dane_issuer(X509_STORE_CTX *ctx, int depth);
   81 static int check_key_level(X509_STORE_CTX *ctx, X509 *cert);
   82 static int check_sig_level(X509_STORE_CTX *ctx, X509 *cert);
   83 
   84 static int get_crl_score(X509_STORE_CTX *ctx, X509 **pissuer,
   85                          unsigned int *preasons, X509_CRL *crl, X509 *x);
   86 static int get_crl_delta(X509_STORE_CTX *ctx,
   87                          X509_CRL **pcrl, X509_CRL **pdcrl, X509 *x);
   88 static void get_delta_sk(X509_STORE_CTX *ctx, X509_CRL **dcrl,
   89                          int *pcrl_score, X509_CRL *base,
   90                          STACK_OF(X509_CRL) *crls);
   91 static void crl_akid_check(X509_STORE_CTX *ctx, X509_CRL *crl, X509 **pissuer,
   92                            int *pcrl_score);
   93 static int crl_crldp_check(X509 *x, X509_CRL *crl, int crl_score,
   94                            unsigned int *preasons);
   95 static int check_crl_path(X509_STORE_CTX *ctx, X509 *x);
   96 static int check_crl_chain(X509_STORE_CTX *ctx,
   97                            STACK_OF(X509) *cert_path,
   98                            STACK_OF(X509) *crl_path);
   99 
  100 static int internal_verify(X509_STORE_CTX *ctx);
  101 
  102 static int null_callback(int ok, X509_STORE_CTX *e)
  103 {
  104     return ok;
  105 }
  106 
  107 /* Return 1 is a certificate is self signed */
  108 static int cert_self_signed(X509 *x)
  109 {
  110     if (X509_check_purpose(x, -1, 0) != 1)
  111         return 0;
  112     if (x->ex_flags & EXFLAG_SS)
  113         return 1;
  114     else
  115         return 0;
  116 }
  117 
  118 /* Given a certificate try and find an exact match in the store */
  119 
  120 static X509 *lookup_cert_match(X509_STORE_CTX *ctx, X509 *x)
  121 {
  122     STACK_OF(X509) *certs;
  123     X509 *xtmp = NULL;
  124     int i;
  125     /* Lookup all certs with matching subject name */
  126     certs = ctx->lookup_certs(ctx, X509_get_subject_name(x));
  127     if (certs == NULL)
  128         return NULL;
  129     /* Look for exact match */
  130     for (i = 0; i < sk_X509_num(certs); i++) {
  131         xtmp = sk_X509_value(certs, i);
  132         if (!X509_cmp(xtmp, x))
  133             break;
  134     }
  135     if (i < sk_X509_num(certs))
  136         X509_up_ref(xtmp);
  137     else
  138         xtmp = NULL;
  139     sk_X509_pop_free(certs, X509_free);
  140     return xtmp;
  141 }
  142 
  143 /*-
  144  * Inform the verify callback of an error.
  145  * If B<x> is not NULL it is the error cert, otherwise use the chain cert at
  146  * B<depth>.
  147  * If B<err> is not X509_V_OK, that's the error value, otherwise leave
  148  * unchanged (presumably set by the caller).
  149  *
  150  * Returns 0 to abort verification with an error, non-zero to continue.
  151  */
  152 static int verify_cb_cert(X509_STORE_CTX *ctx, X509 *x, int depth, int err)
  153 {
  154     ctx->error_depth = depth;
  155     ctx->current_cert = (x != NULL) ? x : sk_X509_value(ctx->chain, depth);
  156     if (err != X509_V_OK)
  157         ctx->error = err;
  158     return ctx->verify_cb(0, ctx);
  159 }
  160 
  161 /*-
  162  * Inform the verify callback of an error, CRL-specific variant.  Here, the
  163  * error depth and certificate are already set, we just specify the error
  164  * number.
  165  *
  166  * Returns 0 to abort verification with an error, non-zero to continue.
  167  */
  168 static int verify_cb_crl(X509_STORE_CTX *ctx, int err)
  169 {
  170     ctx->error = err;
  171     return ctx->verify_cb(0, ctx);
  172 }
  173 
  174 static int check_auth_level(X509_STORE_CTX *ctx)
  175 {
  176     int i;
  177     int num = sk_X509_num(ctx->chain);
  178 
  179     if (ctx->param->auth_level <= 0)
  180         return 1;
  181 
  182     for (i = 0; i < num; ++i) {
  183         X509 *cert = sk_X509_value(ctx->chain, i);
  184 
  185         /*
  186          * We've already checked the security of the leaf key, so here we only
  187          * check the security of issuer keys.
  188          */
  189         if (i > 0 && !check_key_level(ctx, cert) &&
  190             verify_cb_cert(ctx, cert, i, X509_V_ERR_CA_KEY_TOO_SMALL) == 0)
  191             return 0;
  192         /*
  193          * We also check the signature algorithm security of all certificates
  194          * except those of the trust anchor at index num-1.
  195          */
  196         if (i < num - 1 && !check_sig_level(ctx, cert) &&
  197             verify_cb_cert(ctx, cert, i, X509_V_ERR_CA_MD_TOO_WEAK) == 0)
  198             return 0;
  199     }
  200     return 1;
  201 }
  202 
  203 static int verify_chain(X509_STORE_CTX *ctx)
  204 {
  205     int err;
  206     int ok;
  207 
  208     /*
  209      * Before either returning with an error, or continuing with CRL checks,
  210      * instantiate chain public key parameters.
  211      */
  212     if ((ok = build_chain(ctx)) == 0 ||
  213         (ok = check_chain_extensions(ctx)) == 0 ||
  214         (ok = check_auth_level(ctx)) == 0 ||
  215         (ok = check_id(ctx)) == 0 || 1)
  216         X509_get_pubkey_parameters(NULL, ctx->chain);
  217     if (ok == 0 || (ok = ctx->check_revocation(ctx)) == 0)
  218         return ok;
  219 
  220     err = X509_chain_check_suiteb(&ctx->error_depth, NULL, ctx->chain,
  221                                   ctx->param->flags);
  222     if (err != X509_V_OK) {
  223         if ((ok = verify_cb_cert(ctx, NULL, ctx->error_depth, err)) == 0)
  224             return ok;
  225     }
  226 
  227     /* Verify chain signatures and expiration times */
  228     ok = (ctx->verify != NULL) ? ctx->verify(ctx) : internal_verify(ctx);
  229     if (!ok)
  230         return ok;
  231 
  232     if ((ok = check_name_constraints(ctx)) == 0)
  233         return ok;
  234 
  235 #ifndef OPENSSL_NO_RFC3779
  236     /* RFC 3779 path validation, now that CRL check has been done */
  237     if ((ok = X509v3_asid_validate_path(ctx)) == 0)
  238         return ok;
  239     if ((ok = X509v3_addr_validate_path(ctx)) == 0)
  240         return ok;
  241 #endif
  242 
  243     /* If we get this far evaluate policies */
  244     if (ctx->param->flags & X509_V_FLAG_POLICY_CHECK)
  245         ok = ctx->check_policy(ctx);
  246     return ok;
  247 }
  248 
  249 int X509_verify_cert(X509_STORE_CTX *ctx)
  250 {
  251     SSL_DANE *dane = ctx->dane;
  252     int ret;
  253 
  254     if (ctx->cert == NULL) {
  255         X509err(X509_F_X509_VERIFY_CERT, X509_R_NO_CERT_SET_FOR_US_TO_VERIFY);
  256         ctx->error = X509_V_ERR_INVALID_CALL;
  257         return -1;
  258     }
  259 
  260     if (ctx->chain != NULL) {
  261         /*
  262          * This X509_STORE_CTX has already been used to verify a cert. We
  263          * cannot do another one.
  264          */
  265         X509err(X509_F_X509_VERIFY_CERT, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
  266         ctx->error = X509_V_ERR_INVALID_CALL;
  267         return -1;
  268     }
  269 
  270     /*
  271      * first we make sure the chain we are going to build is present and that
  272      * the first entry is in place
  273      */
  274     if (((ctx->chain = sk_X509_new_null()) == NULL) ||
  275         (!sk_X509_push(ctx->chain, ctx->cert))) {
  276         X509err(X509_F_X509_VERIFY_CERT, ERR_R_MALLOC_FAILURE);
  277         ctx->error = X509_V_ERR_OUT_OF_MEM;
  278         return -1;
  279     }
  280     X509_up_ref(ctx->cert);
  281     ctx->num_untrusted = 1;
  282 
  283     /* If the peer's public key is too weak, we can stop early. */
  284     if (!check_key_level(ctx, ctx->cert) &&
  285         !verify_cb_cert(ctx, ctx->cert, 0, X509_V_ERR_EE_KEY_TOO_SMALL))
  286         return 0;
  287 
  288     if (DANETLS_ENABLED(dane))
  289         ret = dane_verify(ctx);
  290     else
  291         ret = verify_chain(ctx);
  292 
  293     /*
  294      * Safety-net.  If we are returning an error, we must also set ctx->error,
  295      * so that the chain is not considered verified should the error be ignored
  296      * (e.g. TLS with SSL_VERIFY_NONE).
  297      */
  298     if (ret <= 0 && ctx->error == X509_V_OK)
  299         ctx->error = X509_V_ERR_UNSPECIFIED;
  300     return ret;
  301 }
  302 
  303 /*
  304  * Given a STACK_OF(X509) find the issuer of cert (if any)
  305  */
  306 static X509 *find_issuer(X509_STORE_CTX *ctx, STACK_OF(X509) *sk, X509 *x)
  307 {
  308     int i;
  309     X509 *issuer, *rv = NULL;
  310 
  311     for (i = 0; i < sk_X509_num(sk); i++) {
  312         issuer = sk_X509_value(sk, i);
  313         if (ctx->check_issued(ctx, x, issuer)) {
  314             rv = issuer;
  315             if (x509_check_cert_time(ctx, rv, -1))
  316                 break;
  317         }
  318     }
  319     return rv;
  320 }
  321 
  322 /* Given a possible certificate and issuer check them */
  323 
  324 static int check_issued(X509_STORE_CTX *ctx, X509 *x, X509 *issuer)
  325 {
  326     int ret;
  327     if (x == issuer)
  328         return cert_self_signed(x);
  329     ret = X509_check_issued(issuer, x);
  330     if (ret == X509_V_OK) {
  331         int i;
  332         X509 *ch;
  333         /* Special case: single self signed certificate */
  334         if (cert_self_signed(x) && sk_X509_num(ctx->chain) == 1)
  335             return 1;
  336         for (i = 0; i < sk_X509_num(ctx->chain); i++) {
  337             ch = sk_X509_value(ctx->chain, i);
  338             if (ch == issuer || !X509_cmp(ch, issuer)) {
  339                 ret = X509_V_ERR_PATH_LOOP;
  340                 break;
  341             }
  342         }
  343     }
  344 
  345     return (ret == X509_V_OK);
  346 }
  347 
  348 /* Alternative lookup method: look from a STACK stored in other_ctx */
  349 
  350 static int get_issuer_sk(X509 **issuer, X509_STORE_CTX *ctx, X509 *x)
  351 {
  352     *issuer = find_issuer(ctx, ctx->other_ctx, x);
  353     if (*issuer) {
  354         X509_up_ref(*issuer);
  355         return 1;
  356     } else
  357         return 0;
  358 }
  359 
  360 static STACK_OF(X509) *lookup_certs_sk(X509_STORE_CTX *ctx, X509_NAME *nm)
  361 {
  362     STACK_OF(X509) *sk = NULL;
  363     X509 *x;
  364     int i;
  365 
  366     for (i = 0; i < sk_X509_num(ctx->other_ctx); i++) {
  367         x = sk_X509_value(ctx->other_ctx, i);
  368         if (X509_NAME_cmp(nm, X509_get_subject_name(x)) == 0) {
  369             if (sk == NULL)
  370                 sk = sk_X509_new_null();
  371             if (sk == NULL || sk_X509_push(sk, x) == 0) {
  372                 sk_X509_pop_free(sk, X509_free);
  373                 X509err(X509_F_LOOKUP_CERTS_SK, ERR_R_MALLOC_FAILURE);
  374                 ctx->error = X509_V_ERR_OUT_OF_MEM;
  375                 return NULL;
  376             }
  377             X509_up_ref(x);
  378         }
  379     }
  380     return sk;
  381 }
  382 
  383 /*
  384  * Check EE or CA certificate purpose.  For trusted certificates explicit local
  385  * auxiliary trust can be used to override EKU-restrictions.
  386  */
  387 static int check_purpose(X509_STORE_CTX *ctx, X509 *x, int purpose, int depth,
  388                          int must_be_ca)
  389 {
  390     int tr_ok = X509_TRUST_UNTRUSTED;
  391 
  392     /*
  393      * For trusted certificates we want to see whether any auxiliary trust
  394      * settings trump the purpose constraints.
  395      *
  396      * This is complicated by the fact that the trust ordinals in
  397      * ctx->param->trust are entirely independent of the purpose ordinals in
  398      * ctx->param->purpose!
  399      *
  400      * What connects them is their mutual initialization via calls from
  401      * X509_STORE_CTX_set_default() into X509_VERIFY_PARAM_lookup() which sets
  402      * related values of both param->trust and param->purpose.  It is however
  403      * typically possible to infer associated trust values from a purpose value
  404      * via the X509_PURPOSE API.
  405      *
  406      * Therefore, we can only check for trust overrides when the purpose we're
  407      * checking is the same as ctx->param->purpose and ctx->param->trust is
  408      * also set.
  409      */
  410     if (depth >= ctx->num_untrusted && purpose == ctx->param->purpose)
  411         tr_ok = X509_check_trust(x, ctx->param->trust, X509_TRUST_NO_SS_COMPAT);
  412 
  413     switch (tr_ok) {
  414     case X509_TRUST_TRUSTED:
  415         return 1;
  416     case X509_TRUST_REJECTED:
  417         break;
  418     default:
  419         switch (X509_check_purpose(x, purpose, must_be_ca > 0)) {
  420         case 1:
  421             return 1;
  422         case 0:
  423             break;
  424         default:
  425             if ((ctx->param->flags & X509_V_FLAG_X509_STRICT) == 0)
  426                 return 1;
  427         }
  428         break;
  429     }
  430 
  431     return verify_cb_cert(ctx, x, depth, X509_V_ERR_INVALID_PURPOSE);
  432 }
  433 
  434 /*
  435  * Check a certificate chains extensions for consistency with the supplied
  436  * purpose
  437  */
  438 
  439 static int check_chain_extensions(X509_STORE_CTX *ctx)
  440 {
  441     int i, must_be_ca, plen = 0;
  442     X509 *x;
  443     int proxy_path_length = 0;
  444     int purpose;
  445     int allow_proxy_certs;
  446     int num = sk_X509_num(ctx->chain);
  447 
  448     /*-
  449      *  must_be_ca can have 1 of 3 values:
  450      * -1: we accept both CA and non-CA certificates, to allow direct
  451      *     use of self-signed certificates (which are marked as CA).
  452      * 0:  we only accept non-CA certificates.  This is currently not
  453      *     used, but the possibility is present for future extensions.
  454      * 1:  we only accept CA certificates.  This is currently used for
  455      *     all certificates in the chain except the leaf certificate.
  456      */
  457     must_be_ca = -1;
  458 
  459     /* CRL path validation */
  460     if (ctx->parent) {
  461         allow_proxy_certs = 0;
  462         purpose = X509_PURPOSE_CRL_SIGN;
  463     } else {
  464         allow_proxy_certs =
  465             ! !(ctx->param->flags & X509_V_FLAG_ALLOW_PROXY_CERTS);
  466         purpose = ctx->param->purpose;
  467     }
  468 
  469     for (i = 0; i < num; i++) {
  470         int ret;
  471         x = sk_X509_value(ctx->chain, i);
  472         if (!(ctx->param->flags & X509_V_FLAG_IGNORE_CRITICAL)
  473             && (x->ex_flags & EXFLAG_CRITICAL)) {
  474             if (!verify_cb_cert(ctx, x, i,
  475                                 X509_V_ERR_UNHANDLED_CRITICAL_EXTENSION))
  476                 return 0;
  477         }
  478         if (!allow_proxy_certs && (x->ex_flags & EXFLAG_PROXY)) {
  479             if (!verify_cb_cert(ctx, x, i,
  480                                 X509_V_ERR_PROXY_CERTIFICATES_NOT_ALLOWED))
  481                 return 0;
  482         }
  483         ret = X509_check_ca(x);
  484         switch (must_be_ca) {
  485         case -1:
  486             if ((ctx->param->flags & X509_V_FLAG_X509_STRICT)
  487                 && (ret != 1) && (ret != 0)) {
  488                 ret = 0;
  489                 ctx->error = X509_V_ERR_INVALID_CA;
  490             } else
  491                 ret = 1;
  492             break;
  493         case 0:
  494             if (ret != 0) {
  495                 ret = 0;
  496                 ctx->error = X509_V_ERR_INVALID_NON_CA;
  497             } else
  498                 ret = 1;
  499             break;
  500         default:
  501             /* X509_V_FLAG_X509_STRICT is implicit for intermediate CAs */
  502             if ((ret == 0)
  503                 || ((i + 1 < num || ctx->param->flags & X509_V_FLAG_X509_STRICT)
  504                     && (ret != 1))) {
  505                 ret = 0;
  506                 ctx->error = X509_V_ERR_INVALID_CA;
  507             } else
  508                 ret = 1;
  509             break;
  510         }
  511         if ((x->ex_flags & EXFLAG_CA) == 0
  512             && x->ex_pathlen != -1
  513             && (ctx->param->flags & X509_V_FLAG_X509_STRICT)) {
  514             ctx->error = X509_V_ERR_INVALID_EXTENSION;
  515             ret = 0;
  516         }
  517         if (ret == 0 && !verify_cb_cert(ctx, x, i, X509_V_OK))
  518             return 0;
  519         /* check_purpose() makes the callback as needed */
  520         if (purpose > 0 && !check_purpose(ctx, x, purpose, i, must_be_ca))
  521             return 0;
  522         /* Check pathlen */
  523         if ((i > 1) && (x->ex_pathlen != -1)
  524             && (plen > (x->ex_pathlen + proxy_path_length))) {
  525             if (!verify_cb_cert(ctx, x, i, X509_V_ERR_PATH_LENGTH_EXCEEDED))
  526                 return 0;
  527         }
  528         /* Increment path length if not a self issued intermediate CA */
  529         if (i > 0 && (x->ex_flags & EXFLAG_SI) == 0)
  530             plen++;
  531         /*
  532          * If this certificate is a proxy certificate, the next certificate
  533          * must be another proxy certificate or a EE certificate.  If not,
  534          * the next certificate must be a CA certificate.
  535          */
  536         if (x->ex_flags & EXFLAG_PROXY) {
  537             /*
  538              * RFC3820, 4.1.3 (b)(1) stipulates that if pCPathLengthConstraint
  539              * is less than max_path_length, the former should be copied to
  540              * the latter, and 4.1.4 (a) stipulates that max_path_length
  541              * should be verified to be larger than zero and decrement it.
  542              *
  543              * Because we're checking the certs in the reverse order, we start
  544              * with verifying that proxy_path_length isn't larger than pcPLC,
  545              * and copy the latter to the former if it is, and finally,
  546              * increment proxy_path_length.
  547              */
  548             if (x->ex_pcpathlen != -1) {
  549                 if (proxy_path_length > x->ex_pcpathlen) {
  550                     if (!verify_cb_cert(ctx, x, i,
  551                                         X509_V_ERR_PROXY_PATH_LENGTH_EXCEEDED))
  552                         return 0;
  553                 }
  554                 proxy_path_length = x->ex_pcpathlen;
  555             }
  556             proxy_path_length++;
  557             must_be_ca = 0;
  558         } else
  559             must_be_ca = 1;
  560     }
  561     return 1;
  562 }
  563 
  564 static int has_san_id(X509 *x, int gtype)
  565 {
  566     int i;
  567     int ret = 0;
  568     GENERAL_NAMES *gs = X509_get_ext_d2i(x, NID_subject_alt_name, NULL, NULL);
  569 
  570     if (gs == NULL)
  571         return 0;
  572 
  573     for (i = 0; i < sk_GENERAL_NAME_num(gs); i++) {
  574         GENERAL_NAME *g = sk_GENERAL_NAME_value(gs, i);
  575 
  576         if (g->type == gtype) {
  577             ret = 1;
  578             break;
  579         }
  580     }
  581     GENERAL_NAMES_free(gs);
  582     return ret;
  583 }
  584 
  585 static int check_name_constraints(X509_STORE_CTX *ctx)
  586 {
  587     int i;
  588 
  589     /* Check name constraints for all certificates */
  590     for (i = sk_X509_num(ctx->chain) - 1; i >= 0; i--) {
  591         X509 *x = sk_X509_value(ctx->chain, i);
  592         int j;
  593 
  594         /* Ignore self issued certs unless last in chain */
  595         if (i && (x->ex_flags & EXFLAG_SI))
  596             continue;
  597 
  598         /*
  599          * Proxy certificates policy has an extra constraint, where the
  600          * certificate subject MUST be the issuer with a single CN entry
  601          * added.
  602          * (RFC 3820: 3.4, 4.1.3 (a)(4))
  603          */
  604         if (x->ex_flags & EXFLAG_PROXY) {
  605             X509_NAME *tmpsubject = X509_get_subject_name(x);
  606             X509_NAME *tmpissuer = X509_get_issuer_name(x);
  607             X509_NAME_ENTRY *tmpentry = NULL;
  608             int last_object_nid = 0;
  609             int err = X509_V_OK;
  610             int last_object_loc = X509_NAME_entry_count(tmpsubject) - 1;
  611 
  612             /* Check that there are at least two RDNs */
  613             if (last_object_loc < 1) {
  614                 err = X509_V_ERR_PROXY_SUBJECT_NAME_VIOLATION;
  615                 goto proxy_name_done;
  616             }
  617 
  618             /*
  619              * Check that there is exactly one more RDN in subject as
  620              * there is in issuer.
  621              */
  622             if (X509_NAME_entry_count(tmpsubject)
  623                 != X509_NAME_entry_count(tmpissuer) + 1) {
  624                 err = X509_V_ERR_PROXY_SUBJECT_NAME_VIOLATION;
  625                 goto proxy_name_done;
  626             }
  627 
  628             /*
  629              * Check that the last subject component isn't part of a
  630              * multivalued RDN
  631              */
  632             if (X509_NAME_ENTRY_set(X509_NAME_get_entry(tmpsubject,
  633                                                         last_object_loc))
  634                 == X509_NAME_ENTRY_set(X509_NAME_get_entry(tmpsubject,
  635                                                            last_object_loc - 1))) {
  636                 err = X509_V_ERR_PROXY_SUBJECT_NAME_VIOLATION;
  637                 goto proxy_name_done;
  638             }
  639 
  640             /*
  641              * Check that the last subject RDN is a commonName, and that
  642              * all the previous RDNs match the issuer exactly
  643              */
  644             tmpsubject = X509_NAME_dup(tmpsubject);
  645             if (tmpsubject == NULL) {
  646                 X509err(X509_F_CHECK_NAME_CONSTRAINTS, ERR_R_MALLOC_FAILURE);
  647                 ctx->error = X509_V_ERR_OUT_OF_MEM;
  648                 return 0;
  649             }
  650 
  651             tmpentry =
  652                 X509_NAME_delete_entry(tmpsubject, last_object_loc);
  653             last_object_nid =
  654                 OBJ_obj2nid(X509_NAME_ENTRY_get_object(tmpentry));
  655 
  656             if (last_object_nid != NID_commonName
  657                 || X509_NAME_cmp(tmpsubject, tmpissuer) != 0) {
  658                 err = X509_V_ERR_PROXY_SUBJECT_NAME_VIOLATION;
  659             }
  660 
  661             X509_NAME_ENTRY_free(tmpentry);
  662             X509_NAME_free(tmpsubject);
  663 
  664          proxy_name_done:
  665             if (err != X509_V_OK
  666                 && !verify_cb_cert(ctx, x, i, err))
  667                 return 0;
  668         }
  669 
  670         /*
  671          * Check against constraints for all certificates higher in chain
  672          * including trust anchor. Trust anchor not strictly speaking needed
  673          * but if it includes constraints it is to be assumed it expects them
  674          * to be obeyed.
  675          */
  676         for (j = sk_X509_num(ctx->chain) - 1; j > i; j--) {
  677             NAME_CONSTRAINTS *nc = sk_X509_value(ctx->chain, j)->nc;
  678 
  679             if (nc) {
  680                 int rv = NAME_CONSTRAINTS_check(x, nc);
  681 
  682                 /* If EE certificate check commonName too */
  683                 if (rv == X509_V_OK && i == 0
  684                     && (ctx->param->hostflags
  685                         & X509_CHECK_FLAG_NEVER_CHECK_SUBJECT) == 0
  686                     && ((ctx->param->hostflags
  687                          & X509_CHECK_FLAG_ALWAYS_CHECK_SUBJECT) != 0
  688                         || !has_san_id(x, GEN_DNS)))
  689                     rv = NAME_CONSTRAINTS_check_CN(x, nc);
  690 
  691                 switch (rv) {
  692                 case X509_V_OK:
  693                     break;
  694                 case X509_V_ERR_OUT_OF_MEM:
  695                     return 0;
  696                 default:
  697                     if (!verify_cb_cert(ctx, x, i, rv))
  698                         return 0;
  699                     break;
  700                 }
  701             }
  702         }
  703     }
  704     return 1;
  705 }
  706 
  707 static int check_id_error(X509_STORE_CTX *ctx, int errcode)
  708 {
  709     return verify_cb_cert(ctx, ctx->cert, 0, errcode);
  710 }
  711 
  712 static int check_hosts(X509 *x, X509_VERIFY_PARAM *vpm)
  713 {
  714     int i;
  715     int n = sk_OPENSSL_STRING_num(vpm->hosts);
  716     char *name;
  717 
  718     if (vpm->peername != NULL) {
  719         OPENSSL_free(vpm->peername);
  720         vpm->peername = NULL;
  721     }
  722     for (i = 0; i < n; ++i) {
  723         name = sk_OPENSSL_STRING_value(vpm->hosts, i);
  724         if (X509_check_host(x, name, 0, vpm->hostflags, &vpm->peername) > 0)
  725             return 1;
  726     }
  727     return n == 0;
  728 }
  729 
  730 static int check_id(X509_STORE_CTX *ctx)
  731 {
  732     X509_VERIFY_PARAM *vpm = ctx->param;
  733     X509 *x = ctx->cert;
  734     if (vpm->hosts && check_hosts(x, vpm) <= 0) {
  735         if (!check_id_error(ctx, X509_V_ERR_HOSTNAME_MISMATCH))
  736             return 0;
  737     }
  738     if (vpm->email && X509_check_email(x, vpm->email, vpm->emaillen, 0) <= 0) {
  739         if (!check_id_error(ctx, X509_V_ERR_EMAIL_MISMATCH))
  740             return 0;
  741     }
  742     if (vpm->ip && X509_check_ip(x, vpm->ip, vpm->iplen, 0) <= 0) {
  743         if (!check_id_error(ctx, X509_V_ERR_IP_ADDRESS_MISMATCH))
  744             return 0;
  745     }
  746     return 1;
  747 }
  748 
  749 static int check_trust(X509_STORE_CTX *ctx, int num_untrusted)
  750 {
  751     int i;
  752     X509 *x = NULL;
  753     X509 *mx;
  754     SSL_DANE *dane = ctx->dane;
  755     int num = sk_X509_num(ctx->chain);
  756     int trust;
  757 
  758     /*
  759      * Check for a DANE issuer at depth 1 or greater, if it is a DANE-TA(2)
  760      * match, we're done, otherwise we'll merely record the match depth.
  761      */
  762     if (DANETLS_HAS_TA(dane) && num_untrusted > 0 && num_untrusted < num) {
  763         switch (trust = check_dane_issuer(ctx, num_untrusted)) {
  764         case X509_TRUST_TRUSTED:
  765         case X509_TRUST_REJECTED:
  766             return trust;
  767         }
  768     }
  769 
  770     /*
  771      * Check trusted certificates in chain at depth num_untrusted and up.
  772      * Note, that depths 0..num_untrusted-1 may also contain trusted
  773      * certificates, but the caller is expected to have already checked those,
  774      * and wants to incrementally check just any added since.
  775      */
  776     for (i = num_untrusted; i < num; i++) {
  777         x = sk_X509_value(ctx->chain, i);
  778         trust = X509_check_trust(x, ctx->param->trust, 0);
  779         /* If explicitly trusted return trusted */
  780         if (trust == X509_TRUST_TRUSTED)
  781             goto trusted;
  782         if (trust == X509_TRUST_REJECTED)
  783             goto rejected;
  784     }
  785 
  786     /*
  787      * If we are looking at a trusted certificate, and accept partial chains,
  788      * the chain is PKIX trusted.
  789      */
  790     if (num_untrusted < num) {
  791         if (ctx->param->flags & X509_V_FLAG_PARTIAL_CHAIN)
  792             goto trusted;
  793         return X509_TRUST_UNTRUSTED;
  794     }
  795 
  796     if (num_untrusted == num && ctx->param->flags & X509_V_FLAG_PARTIAL_CHAIN) {
  797         /*
  798          * Last-resort call with no new trusted certificates, check the leaf
  799          * for a direct trust store match.
  800          */
  801         i = 0;
  802         x = sk_X509_value(ctx->chain, i);
  803         mx = lookup_cert_match(ctx, x);
  804         if (!mx)
  805             return X509_TRUST_UNTRUSTED;
  806 
  807         /*
  808          * Check explicit auxiliary trust/reject settings.  If none are set,
  809          * we'll accept X509_TRUST_UNTRUSTED when not self-signed.
  810          */
  811         trust = X509_check_trust(mx, ctx->param->trust, 0);
  812         if (trust == X509_TRUST_REJECTED) {
  813             X509_free(mx);
  814             goto rejected;
  815         }
  816 
  817         /* Replace leaf with trusted match */
  818         (void) sk_X509_set(ctx->chain, 0, mx);
  819         X509_free(x);
  820         ctx->num_untrusted = 0;
  821         goto trusted;
  822     }
  823 
  824     /*
  825      * If no trusted certs in chain at all return untrusted and allow
  826      * standard (no issuer cert) etc errors to be indicated.
  827      */
  828     return X509_TRUST_UNTRUSTED;
  829 
  830  rejected:
  831     if (!verify_cb_cert(ctx, x, i, X509_V_ERR_CERT_REJECTED))
  832         return X509_TRUST_REJECTED;
  833     return X509_TRUST_UNTRUSTED;
  834 
  835  trusted:
  836     if (!DANETLS_ENABLED(dane))
  837         return X509_TRUST_TRUSTED;
  838     if (dane->pdpth < 0)
  839         dane->pdpth = num_untrusted;
  840     /* With DANE, PKIX alone is not trusted until we have both */
  841     if (dane->mdpth >= 0)
  842         return X509_TRUST_TRUSTED;
  843     return X509_TRUST_UNTRUSTED;
  844 }
  845 
  846 static int check_revocation(X509_STORE_CTX *ctx)
  847 {
  848     int i = 0, last = 0, ok = 0;
  849     if (!(ctx->param->flags & X509_V_FLAG_CRL_CHECK))
  850         return 1;
  851     if (ctx->param->flags & X509_V_FLAG_CRL_CHECK_ALL)
  852         last = sk_X509_num(ctx->chain) - 1;
  853     else {
  854         /* If checking CRL paths this isn't the EE certificate */
  855         if (ctx->parent)
  856             return 1;
  857         last = 0;
  858     }
  859     for (i = 0; i <= last; i++) {
  860         ctx->error_depth = i;
  861         ok = check_cert(ctx);
  862         if (!ok)
  863             return ok;
  864     }
  865     return 1;
  866 }
  867 
  868 static int check_cert(X509_STORE_CTX *ctx)
  869 {
  870     X509_CRL *crl = NULL, *dcrl = NULL;
  871     int ok = 0;
  872     int cnum = ctx->error_depth;
  873     X509 *x = sk_X509_value(ctx->chain, cnum);
  874 
  875     ctx->current_cert = x;
  876     ctx->current_issuer = NULL;
  877     ctx->current_crl_score = 0;
  878     ctx->current_reasons = 0;
  879 
  880     if (x->ex_flags & EXFLAG_PROXY)
  881         return 1;
  882 
  883     while (ctx->current_reasons != CRLDP_ALL_REASONS) {
  884         unsigned int last_reasons = ctx->current_reasons;
  885 
  886         /* Try to retrieve relevant CRL */
  887         if (ctx->get_crl)
  888             ok = ctx->get_crl(ctx, &crl, x);
  889         else
  890             ok = get_crl_delta(ctx, &crl, &dcrl, x);
  891         /*
  892          * If error looking up CRL, nothing we can do except notify callback
  893          */
  894         if (!ok) {
  895             ok = verify_cb_crl(ctx, X509_V_ERR_UNABLE_TO_GET_CRL);
  896             goto done;
  897         }
  898         ctx->current_crl = crl;
  899         ok = ctx->check_crl(ctx, crl);
  900         if (!ok)
  901             goto done;
  902 
  903         if (dcrl) {
  904             ok = ctx->check_crl(ctx, dcrl);
  905             if (!ok)
  906                 goto done;
  907             ok = ctx->cert_crl(ctx, dcrl, x);
  908             if (!ok)
  909                 goto done;
  910         } else
  911             ok = 1;
  912 
  913         /* Don't look in full CRL if delta reason is removefromCRL */
  914         if (ok != 2) {
  915             ok = ctx->cert_crl(ctx, crl, x);
  916             if (!ok)
  917                 goto done;
  918         }
  919 
  920         X509_CRL_free(crl);
  921         X509_CRL_free(dcrl);
  922         crl = NULL;
  923         dcrl = NULL;
  924         /*
  925          * If reasons not updated we won't get anywhere by another iteration,
  926          * so exit loop.
  927          */
  928         if (last_reasons == ctx->current_reasons) {
  929             ok = verify_cb_crl(ctx, X509_V_ERR_UNABLE_TO_GET_CRL);
  930             goto done;
  931         }
  932     }
  933  done:
  934     X509_CRL_free(crl);
  935     X509_CRL_free(dcrl);
  936 
  937     ctx->current_crl = NULL;
  938     return ok;
  939 }
  940 
  941 /* Check CRL times against values in X509_STORE_CTX */
  942 
  943 static int check_crl_time(X509_STORE_CTX *ctx, X509_CRL *crl, int notify)
  944 {
  945     time_t *ptime;
  946     int i;
  947 
  948     if (notify)
  949         ctx->current_crl = crl;
  950     if (ctx->param->flags & X509_V_FLAG_USE_CHECK_TIME)
  951         ptime = &ctx->param->check_time;
  952     else if (ctx->param->flags & X509_V_FLAG_NO_CHECK_TIME)
  953         return 1;
  954     else
  955         ptime = NULL;
  956 
  957     i = X509_cmp_time(X509_CRL_get0_lastUpdate(crl), ptime);
  958     if (i == 0) {
  959         if (!notify)
  960             return 0;
  961         if (!verify_cb_crl(ctx, X509_V_ERR_ERROR_IN_CRL_LAST_UPDATE_FIELD))
  962             return 0;
  963     }
  964 
  965     if (i > 0) {
  966         if (!notify)
  967             return 0;
  968         if (!verify_cb_crl(ctx, X509_V_ERR_CRL_NOT_YET_VALID))
  969             return 0;
  970     }
  971 
  972     if (X509_CRL_get0_nextUpdate(crl)) {
  973         i = X509_cmp_time(X509_CRL_get0_nextUpdate(crl), ptime);
  974 
  975         if (i == 0) {
  976             if (!notify)
  977                 return 0;
  978             if (!verify_cb_crl(ctx, X509_V_ERR_ERROR_IN_CRL_NEXT_UPDATE_FIELD))
  979                 return 0;
  980         }
  981         /* Ignore expiry of base CRL is delta is valid */
  982         if ((i < 0) && !(ctx->current_crl_score & CRL_SCORE_TIME_DELTA)) {
  983             if (!notify)
  984                 return 0;
  985             if (!verify_cb_crl(ctx, X509_V_ERR_CRL_HAS_EXPIRED))
  986                 return 0;
  987         }
  988     }
  989 
  990     if (notify)
  991         ctx->current_crl = NULL;
  992 
  993     return 1;
  994 }
  995 
  996 static int get_crl_sk(X509_STORE_CTX *ctx, X509_CRL **pcrl, X509_CRL **pdcrl,
  997                       X509 **pissuer, int *pscore, unsigned int *preasons,
  998                       STACK_OF(X509_CRL) *crls)
  999 {
 1000     int i, crl_score, best_score = *pscore;
 1001     unsigned int reasons, best_reasons = 0;
 1002     X509 *x = ctx->current_cert;
 1003     X509_CRL *crl, *best_crl = NULL;
 1004     X509 *crl_issuer = NULL, *best_crl_issuer = NULL;
 1005 
 1006     for (i = 0; i < sk_X509_CRL_num(crls); i++) {
 1007         crl = sk_X509_CRL_value(crls, i);
 1008         reasons = *preasons;
 1009         crl_score = get_crl_score(ctx, &crl_issuer, &reasons, crl, x);
 1010         if (crl_score < best_score || crl_score == 0)
 1011             continue;
 1012         /* If current CRL is equivalent use it if it is newer */
 1013         if (crl_score == best_score && best_crl != NULL) {
 1014             int day, sec;
 1015             if (ASN1_TIME_diff(&day, &sec, X509_CRL_get0_lastUpdate(best_crl),
 1016                                X509_CRL_get0_lastUpdate(crl)) == 0)
 1017                 continue;
 1018             /*
 1019              * ASN1_TIME_diff never returns inconsistent signs for |day|
 1020              * and |sec|.
 1021              */
 1022             if (day <= 0 && sec <= 0)
 1023                 continue;
 1024         }
 1025         best_crl = crl;
 1026         best_crl_issuer = crl_issuer;
 1027         best_score = crl_score;
 1028         best_reasons = reasons;
 1029     }
 1030 
 1031     if (best_crl) {
 1032         X509_CRL_free(*pcrl);
 1033         *pcrl = best_crl;
 1034         *pissuer = best_crl_issuer;
 1035         *pscore = best_score;
 1036         *preasons = best_reasons;
 1037         X509_CRL_up_ref(best_crl);
 1038         X509_CRL_free(*pdcrl);
 1039         *pdcrl = NULL;
 1040         get_delta_sk(ctx, pdcrl, pscore, best_crl, crls);
 1041     }
 1042 
 1043     if (best_score >= CRL_SCORE_VALID)
 1044         return 1;
 1045 
 1046     return 0;
 1047 }
 1048 
 1049 /*
 1050  * Compare two CRL extensions for delta checking purposes. They should be
 1051  * both present or both absent. If both present all fields must be identical.
 1052  */
 1053 
 1054 static int crl_extension_match(X509_CRL *a, X509_CRL *b, int nid)
 1055 {
 1056     ASN1_OCTET_STRING *exta, *extb;
 1057     int i;
 1058     i = X509_CRL_get_ext_by_NID(a, nid, -1);
 1059     if (i >= 0) {
 1060         /* Can't have multiple occurrences */
 1061         if (X509_CRL_get_ext_by_NID(a, nid, i) != -1)
 1062             return 0;
 1063         exta = X509_EXTENSION_get_data(X509_CRL_get_ext(a, i));
 1064     } else
 1065         exta = NULL;
 1066 
 1067     i = X509_CRL_get_ext_by_NID(b, nid, -1);
 1068 
 1069     if (i >= 0) {
 1070 
 1071         if (X509_CRL_get_ext_by_NID(b, nid, i) != -1)
 1072             return 0;
 1073         extb = X509_EXTENSION_get_data(X509_CRL_get_ext(b, i));
 1074     } else
 1075         extb = NULL;
 1076 
 1077     if (!exta && !extb)
 1078         return 1;
 1079 
 1080     if (!exta || !extb)
 1081         return 0;
 1082 
 1083     if (ASN1_OCTET_STRING_cmp(exta, extb))
 1084         return 0;
 1085 
 1086     return 1;
 1087 }
 1088 
 1089 /* See if a base and delta are compatible */
 1090 
 1091 static int check_delta_base(X509_CRL *delta, X509_CRL *base)
 1092 {
 1093     /* Delta CRL must be a delta */
 1094     if (!delta->base_crl_number)
 1095         return 0;
 1096     /* Base must have a CRL number */
 1097     if (!base->crl_number)
 1098         return 0;
 1099     /* Issuer names must match */
 1100     if (X509_NAME_cmp(X509_CRL_get_issuer(base), X509_CRL_get_issuer(delta)))
 1101         return 0;
 1102     /* AKID and IDP must match */
 1103     if (!crl_extension_match(delta, base, NID_authority_key_identifier))
 1104         return 0;
 1105     if (!crl_extension_match(delta, base, NID_issuing_distribution_point))
 1106         return 0;
 1107     /* Delta CRL base number must not exceed Full CRL number. */
 1108     if (ASN1_INTEGER_cmp(delta->base_crl_number, base->crl_number) > 0)
 1109         return 0;
 1110     /* Delta CRL number must exceed full CRL number */
 1111     if (ASN1_INTEGER_cmp(delta->crl_number, base->crl_number) > 0)
 1112         return 1;
 1113     return 0;
 1114 }
 1115 
 1116 /*
 1117  * For a given base CRL find a delta... maybe extend to delta scoring or
 1118  * retrieve a chain of deltas...
 1119  */
 1120 
 1121 static void get_delta_sk(X509_STORE_CTX *ctx, X509_CRL **dcrl, int *pscore,
 1122                          X509_CRL *base, STACK_OF(X509_CRL) *crls)
 1123 {
 1124     X509_CRL *delta;
 1125     int i;
 1126     if (!(ctx->param->flags & X509_V_FLAG_USE_DELTAS))
 1127         return;
 1128     if (!((ctx->current_cert->ex_flags | base->flags) & EXFLAG_FRESHEST))
 1129         return;
 1130     for (i = 0; i < sk_X509_CRL_num(crls); i++) {
 1131         delta = sk_X509_CRL_value(crls, i);
 1132         if (check_delta_base(delta, base)) {
 1133             if (check_crl_time(ctx, delta, 0))
 1134                 *pscore |= CRL_SCORE_TIME_DELTA;
 1135             X509_CRL_up_ref(delta);
 1136             *dcrl = delta;
 1137             return;
 1138         }
 1139     }
 1140     *dcrl = NULL;
 1141 }
 1142 
 1143 /*
 1144  * For a given CRL return how suitable it is for the supplied certificate
 1145  * 'x'. The return value is a mask of several criteria. If the issuer is not
 1146  * the certificate issuer this is returned in *pissuer. The reasons mask is
 1147  * also used to determine if the CRL is suitable: if no new reasons the CRL
 1148  * is rejected, otherwise reasons is updated.
 1149  */
 1150 
 1151 static int get_crl_score(X509_STORE_CTX *ctx, X509 **pissuer,
 1152                          unsigned int *preasons, X509_CRL *crl, X509 *x)
 1153 {
 1154 
 1155     int crl_score = 0;
 1156     unsigned int tmp_reasons = *preasons, crl_reasons;
 1157 
 1158     /* First see if we can reject CRL straight away */
 1159 
 1160     /* Invalid IDP cannot be processed */
 1161     if (crl->idp_flags & IDP_INVALID)
 1162         return 0;
 1163     /* Reason codes or indirect CRLs need extended CRL support */
 1164     if (!(ctx->param->flags & X509_V_FLAG_EXTENDED_CRL_SUPPORT)) {
 1165         if (crl->idp_flags & (IDP_INDIRECT | IDP_REASONS))
 1166             return 0;
 1167     } else if (crl->idp_flags & IDP_REASONS) {
 1168         /* If no new reasons reject */
 1169         if (!(crl->idp_reasons & ~tmp_reasons))
 1170             return 0;
 1171     }
 1172     /* Don't process deltas at this stage */
 1173     else if (crl->base_crl_number)
 1174         return 0;
 1175     /* If issuer name doesn't match certificate need indirect CRL */
 1176     if (X509_NAME_cmp(X509_get_issuer_name(x), X509_CRL_get_issuer(crl))) {
 1177         if (!(crl->idp_flags & IDP_INDIRECT))
 1178             return 0;
 1179     } else
 1180         crl_score |= CRL_SCORE_ISSUER_NAME;
 1181 
 1182     if (!(crl->flags & EXFLAG_CRITICAL))
 1183         crl_score |= CRL_SCORE_NOCRITICAL;
 1184 
 1185     /* Check expiry */
 1186     if (check_crl_time(ctx, crl, 0))
 1187         crl_score |= CRL_SCORE_TIME;
 1188 
 1189     /* Check authority key ID and locate certificate issuer */
 1190     crl_akid_check(ctx, crl, pissuer, &crl_score);
 1191 
 1192     /* If we can't locate certificate issuer at this point forget it */
 1193 
 1194     if (!(crl_score & CRL_SCORE_AKID))
 1195         return 0;
 1196 
 1197     /* Check cert for matching CRL distribution points */
 1198 
 1199     if (crl_crldp_check(x, crl, crl_score, &crl_reasons)) {
 1200         /* If no new reasons reject */
 1201         if (!(crl_reasons & ~tmp_reasons))
 1202             return 0;
 1203         tmp_reasons |= crl_reasons;
 1204         crl_score |= CRL_SCORE_SCOPE;
 1205     }
 1206 
 1207     *preasons = tmp_reasons;
 1208 
 1209     return crl_score;
 1210 
 1211 }
 1212 
 1213 static void crl_akid_check(X509_STORE_CTX *ctx, X509_CRL *crl,
 1214                            X509 **pissuer, int *pcrl_score)
 1215 {
 1216     X509 *crl_issuer = NULL;
 1217     X509_NAME *cnm = X509_CRL_get_issuer(crl);
 1218     int cidx = ctx->error_depth;
 1219     int i;
 1220 
 1221     if (cidx != sk_X509_num(ctx->chain) - 1)
 1222         cidx++;
 1223 
 1224     crl_issuer = sk_X509_value(ctx->chain, cidx);
 1225 
 1226     if (X509_check_akid(crl_issuer, crl->akid) == X509_V_OK) {
 1227         if (*pcrl_score & CRL_SCORE_ISSUER_NAME) {
 1228             *pcrl_score |= CRL_SCORE_AKID | CRL_SCORE_ISSUER_CERT;
 1229             *pissuer = crl_issuer;
 1230             return;
 1231         }
 1232     }
 1233 
 1234     for (cidx++; cidx < sk_X509_num(ctx->chain); cidx++) {
 1235         crl_issuer = sk_X509_value(ctx->chain, cidx);
 1236         if (X509_NAME_cmp(X509_get_subject_name(crl_issuer), cnm))
 1237             continue;
 1238         if (X509_check_akid(crl_issuer, crl->akid) == X509_V_OK) {
 1239             *pcrl_score |= CRL_SCORE_AKID | CRL_SCORE_SAME_PATH;
 1240             *pissuer = crl_issuer;
 1241             return;
 1242         }
 1243     }
 1244 
 1245     /* Anything else needs extended CRL support */
 1246 
 1247     if (!(ctx->param->flags & X509_V_FLAG_EXTENDED_CRL_SUPPORT))
 1248         return;
 1249 
 1250     /*
 1251      * Otherwise the CRL issuer is not on the path. Look for it in the set of
 1252      * untrusted certificates.
 1253      */
 1254     for (i = 0; i < sk_X509_num(ctx->untrusted); i++) {
 1255         crl_issuer = sk_X509_value(ctx->untrusted, i);
 1256         if (X509_NAME_cmp(X509_get_subject_name(crl_issuer), cnm))
 1257             continue;
 1258         if (X509_check_akid(crl_issuer, crl->akid) == X509_V_OK) {
 1259             *pissuer = crl_issuer;
 1260             *pcrl_score |= CRL_SCORE_AKID;
 1261             return;
 1262         }
 1263     }
 1264 }
 1265 
 1266 /*
 1267  * Check the path of a CRL issuer certificate. This creates a new
 1268  * X509_STORE_CTX and populates it with most of the parameters from the
 1269  * parent. This could be optimised somewhat since a lot of path checking will
 1270  * be duplicated by the parent, but this will rarely be used in practice.
 1271  */
 1272 
 1273 static int check_crl_path(X509_STORE_CTX *ctx, X509 *x)
 1274 {
 1275     X509_STORE_CTX crl_ctx;
 1276     int ret;
 1277 
 1278     /* Don't allow recursive CRL path validation */
 1279     if (ctx->parent)
 1280         return 0;
 1281     if (!X509_STORE_CTX_init(&crl_ctx, ctx->ctx, x, ctx->untrusted))
 1282         return -1;
 1283 
 1284     crl_ctx.crls = ctx->crls;
 1285     /* Copy verify params across */
 1286     X509_STORE_CTX_set0_param(&crl_ctx, ctx->param);
 1287 
 1288     crl_ctx.parent = ctx;
 1289     crl_ctx.verify_cb = ctx->verify_cb;
 1290 
 1291     /* Verify CRL issuer */
 1292     ret = X509_verify_cert(&crl_ctx);
 1293     if (ret <= 0)
 1294         goto err;
 1295 
 1296     /* Check chain is acceptable */
 1297     ret = check_crl_chain(ctx, ctx->chain, crl_ctx.chain);
 1298  err:
 1299     X509_STORE_CTX_cleanup(&crl_ctx);
 1300     return ret;
 1301 }
 1302 
 1303 /*
 1304  * RFC3280 says nothing about the relationship between CRL path and
 1305  * certificate path, which could lead to situations where a certificate could
 1306  * be revoked or validated by a CA not authorised to do so. RFC5280 is more
 1307  * strict and states that the two paths must end in the same trust anchor,
 1308  * though some discussions remain... until this is resolved we use the
 1309  * RFC5280 version
 1310  */
 1311 
 1312 static int check_crl_chain(X509_STORE_CTX *ctx,
 1313                            STACK_OF(X509) *cert_path,
 1314                            STACK_OF(X509) *crl_path)
 1315 {
 1316     X509 *cert_ta, *crl_ta;
 1317     cert_ta = sk_X509_value(cert_path, sk_X509_num(cert_path) - 1);
 1318     crl_ta = sk_X509_value(crl_path, sk_X509_num(crl_path) - 1);
 1319     if (!X509_cmp(cert_ta, crl_ta))
 1320         return 1;
 1321     return 0;
 1322 }
 1323 
 1324 /*-
 1325  * Check for match between two dist point names: three separate cases.
 1326  * 1. Both are relative names and compare X509_NAME types.
 1327  * 2. One full, one relative. Compare X509_NAME to GENERAL_NAMES.
 1328  * 3. Both are full names and compare two GENERAL_NAMES.
 1329  * 4. One is NULL: automatic match.
 1330  */
 1331 
 1332 static int idp_check_dp(DIST_POINT_NAME *a, DIST_POINT_NAME *b)
 1333 {
 1334     X509_NAME *nm = NULL;
 1335     GENERAL_NAMES *gens = NULL;
 1336     GENERAL_NAME *gena, *genb;
 1337     int i, j;
 1338     if (!a || !b)
 1339         return 1;
 1340     if (a->type == 1) {
 1341         if (!a->dpname)
 1342             return 0;
 1343         /* Case 1: two X509_NAME */
 1344         if (b->type == 1) {
 1345             if (!b->dpname)
 1346                 return 0;
 1347             if (!X509_NAME_cmp(a->dpname, b->dpname))
 1348                 return 1;
 1349             else
 1350                 return 0;
 1351         }
 1352         /* Case 2: set name and GENERAL_NAMES appropriately */
 1353         nm = a->dpname;
 1354         gens = b->name.fullname;
 1355     } else if (b->type == 1) {
 1356         if (!b->dpname)
 1357             return 0;
 1358         /* Case 2: set name and GENERAL_NAMES appropriately */
 1359         gens = a->name.fullname;
 1360         nm = b->dpname;
 1361     }
 1362 
 1363     /* Handle case 2 with one GENERAL_NAMES and one X509_NAME */
 1364     if (nm) {
 1365         for (i = 0; i < sk_GENERAL_NAME_num(gens); i++) {
 1366             gena = sk_GENERAL_NAME_value(gens, i);
 1367             if (gena->type != GEN_DIRNAME)
 1368                 continue;
 1369             if (!X509_NAME_cmp(nm, gena->d.directoryName))
 1370                 return 1;
 1371         }
 1372         return 0;
 1373     }
 1374 
 1375     /* Else case 3: two GENERAL_NAMES */
 1376 
 1377     for (i = 0; i < sk_GENERAL_NAME_num(a->name.fullname); i++) {
 1378         gena = sk_GENERAL_NAME_value(a->name.fullname, i);
 1379         for (j = 0; j < sk_GENERAL_NAME_num(b->name.fullname); j++) {
 1380             genb = sk_GENERAL_NAME_value(b->name.fullname, j);
 1381             if (!GENERAL_NAME_cmp(gena, genb))
 1382                 return 1;
 1383         }
 1384     }
 1385 
 1386     return 0;
 1387 
 1388 }
 1389 
 1390 static int crldp_check_crlissuer(DIST_POINT *dp, X509_CRL *crl, int crl_score)
 1391 {
 1392     int i;
 1393     X509_NAME *nm = X509_CRL_get_issuer(crl);
 1394     /* If no CRLissuer return is successful iff don't need a match */
 1395     if (!dp->CRLissuer)
 1396         return ! !(crl_score & CRL_SCORE_ISSUER_NAME);
 1397     for (i = 0; i < sk_GENERAL_NAME_num(dp->CRLissuer); i++) {
 1398         GENERAL_NAME *gen = sk_GENERAL_NAME_value(dp->CRLissuer, i);
 1399         if (gen->type != GEN_DIRNAME)
 1400             continue;
 1401         if (!X509_NAME_cmp(gen->d.directoryName, nm))
 1402             return 1;
 1403     }
 1404     return 0;
 1405 }
 1406 
 1407 /* Check CRLDP and IDP */
 1408 
 1409 static int crl_crldp_check(X509 *x, X509_CRL *crl, int crl_score,
 1410                            unsigned int *preasons)
 1411 {
 1412     int i;
 1413     if (crl->idp_flags & IDP_ONLYATTR)
 1414         return 0;
 1415     if (x->ex_flags & EXFLAG_CA) {
 1416         if (crl->idp_flags & IDP_ONLYUSER)
 1417             return 0;
 1418     } else {
 1419         if (crl->idp_flags & IDP_ONLYCA)
 1420             return 0;
 1421     }
 1422     *preasons = crl->idp_reasons;
 1423     for (i = 0; i < sk_DIST_POINT_num(x->crldp); i++) {
 1424         DIST_POINT *dp = sk_DIST_POINT_value(x->crldp, i);
 1425         if (crldp_check_crlissuer(dp, crl, crl_score)) {
 1426             if (!crl->idp || idp_check_dp(dp->distpoint, crl->idp->distpoint)) {
 1427                 *preasons &= dp->dp_reasons;
 1428                 return 1;
 1429             }
 1430         }
 1431     }
 1432     if ((!crl->idp || !crl->idp->distpoint)
 1433         && (crl_score & CRL_SCORE_ISSUER_NAME))
 1434         return 1;
 1435     return 0;
 1436 }
 1437 
 1438 /*
 1439  * Retrieve CRL corresponding to current certificate. If deltas enabled try
 1440  * to find a delta CRL too
 1441  */
 1442 
 1443 static int get_crl_delta(X509_STORE_CTX *ctx,
 1444                          X509_CRL **pcrl, X509_CRL **pdcrl, X509 *x)
 1445 {
 1446     int ok;
 1447     X509 *issuer = NULL;
 1448     int crl_score = 0;
 1449     unsigned int reasons;
 1450     X509_CRL *crl = NULL, *dcrl = NULL;
 1451     STACK_OF(X509_CRL) *skcrl;
 1452     X509_NAME *nm = X509_get_issuer_name(x);
 1453 
 1454     reasons = ctx->current_reasons;
 1455     ok = get_crl_sk(ctx, &crl, &dcrl,
 1456                     &issuer, &crl_score, &reasons, ctx->crls);
 1457     if (ok)
 1458         goto done;
 1459 
 1460     /* Lookup CRLs from store */
 1461 
 1462     skcrl = ctx->lookup_crls(ctx, nm);
 1463 
 1464     /* If no CRLs found and a near match from get_crl_sk use that */
 1465     if (!skcrl && crl)
 1466         goto done;
 1467 
 1468     get_crl_sk(ctx, &crl, &dcrl, &issuer, &crl_score, &reasons, skcrl);
 1469 
 1470     sk_X509_CRL_pop_free(skcrl, X509_CRL_free);
 1471 
 1472  done:
 1473     /* If we got any kind of CRL use it and return success */
 1474     if (crl) {
 1475         ctx->current_issuer = issuer;
 1476         ctx->current_crl_score = crl_score;
 1477         ctx->current_reasons = reasons;
 1478         *pcrl = crl;
 1479         *pdcrl = dcrl;
 1480         return 1;
 1481     }
 1482     return 0;
 1483 }
 1484 
 1485 /* Check CRL validity */
 1486 static int check_crl(X509_STORE_CTX *ctx, X509_CRL *crl)
 1487 {
 1488     X509 *issuer = NULL;
 1489     EVP_PKEY *ikey = NULL;
 1490     int cnum = ctx->error_depth;
 1491     int chnum = sk_X509_num(ctx->chain) - 1;
 1492 
 1493     /* if we have an alternative CRL issuer cert use that */
 1494     if (ctx->current_issuer)
 1495         issuer = ctx->current_issuer;
 1496     /*
 1497      * Else find CRL issuer: if not last certificate then issuer is next
 1498      * certificate in chain.
 1499      */
 1500     else if (cnum < chnum)
 1501         issuer = sk_X509_value(ctx->chain, cnum + 1);
 1502     else {
 1503         issuer = sk_X509_value(ctx->chain, chnum);
 1504         /* If not self signed, can't check signature */
 1505         if (!ctx->check_issued(ctx, issuer, issuer) &&
 1506             !verify_cb_crl(ctx, X509_V_ERR_UNABLE_TO_GET_CRL_ISSUER))
 1507             return 0;
 1508     }
 1509 
 1510     if (issuer == NULL)
 1511         return 1;
 1512 
 1513     /*
 1514      * Skip most tests for deltas because they have already been done
 1515      */
 1516     if (!crl->base_crl_number) {
 1517         /* Check for cRLSign bit if keyUsage present */
 1518         if ((issuer->ex_flags & EXFLAG_KUSAGE) &&
 1519             !(issuer->ex_kusage & KU_CRL_SIGN) &&
 1520             !verify_cb_crl(ctx, X509_V_ERR_KEYUSAGE_NO_CRL_SIGN))
 1521             return 0;
 1522 
 1523         if (!(ctx->current_crl_score & CRL_SCORE_SCOPE) &&
 1524             !verify_cb_crl(ctx, X509_V_ERR_DIFFERENT_CRL_SCOPE))
 1525             return 0;
 1526 
 1527         if (!(ctx->current_crl_score & CRL_SCORE_SAME_PATH) &&
 1528             check_crl_path(ctx, ctx->current_issuer) <= 0 &&
 1529             !verify_cb_crl(ctx, X509_V_ERR_CRL_PATH_VALIDATION_ERROR))
 1530             return 0;
 1531 
 1532         if ((crl->idp_flags & IDP_INVALID) &&
 1533             !verify_cb_crl(ctx, X509_V_ERR_INVALID_EXTENSION))
 1534             return 0;
 1535     }
 1536 
 1537     if (!(ctx->current_crl_score & CRL_SCORE_TIME) &&
 1538         !check_crl_time(ctx, crl, 1))
 1539         return 0;
 1540 
 1541     /* Attempt to get issuer certificate public key */
 1542     ikey = X509_get0_pubkey(issuer);
 1543 
 1544     if (!ikey &&
 1545         !verify_cb_crl(ctx, X509_V_ERR_UNABLE_TO_DECODE_ISSUER_PUBLIC_KEY))
 1546         return 0;
 1547 
 1548     if (ikey) {
 1549         int rv = X509_CRL_check_suiteb(crl, ikey, ctx->param->flags);
 1550 
 1551         if (rv != X509_V_OK && !verify_cb_crl(ctx, rv))
 1552             return 0;
 1553         /* Verify CRL signature */
 1554         if (X509_CRL_verify(crl, ikey) <= 0 &&
 1555             !verify_cb_crl(ctx, X509_V_ERR_CRL_SIGNATURE_FAILURE))
 1556             return 0;
 1557     }
 1558     return 1;
 1559 }
 1560 
 1561 /* Check certificate against CRL */
 1562 static int cert_crl(X509_STORE_CTX *ctx, X509_CRL *crl, X509 *x)
 1563 {
 1564     X509_REVOKED *rev;
 1565 
 1566     /*
 1567      * The rules changed for this... previously if a CRL contained unhandled
 1568      * critical extensions it could still be used to indicate a certificate
 1569      * was revoked. This has since been changed since critical extensions can
 1570      * change the meaning of CRL entries.
 1571      */
 1572     if (!(ctx->param->flags & X509_V_FLAG_IGNORE_CRITICAL)
 1573         && (crl->flags & EXFLAG_CRITICAL) &&
 1574         !verify_cb_crl(ctx, X509_V_ERR_UNHANDLED_CRITICAL_CRL_EXTENSION))
 1575         return 0;
 1576     /*
 1577      * Look for serial number of certificate in CRL.  If found, make sure
 1578      * reason is not removeFromCRL.
 1579      */
 1580     if (X509_CRL_get0_by_cert(crl, &rev, x)) {
 1581         if (rev->reason == CRL_REASON_REMOVE_FROM_CRL)
 1582             return 2;
 1583         if (!verify_cb_crl(ctx, X509_V_ERR_CERT_REVOKED))
 1584             return 0;
 1585     }
 1586 
 1587     return 1;
 1588 }
 1589 
 1590 static int check_policy(X509_STORE_CTX *ctx)
 1591 {
 1592     int ret;
 1593 
 1594     if (ctx->parent)
 1595         return 1;
 1596     /*
 1597      * With DANE, the trust anchor might be a bare public key, not a
 1598      * certificate!  In that case our chain does not have the trust anchor
 1599      * certificate as a top-most element.  This comports well with RFC5280
 1600      * chain verification, since there too, the trust anchor is not part of the
 1601      * chain to be verified.  In particular, X509_policy_check() does not look
 1602      * at the TA cert, but assumes that it is present as the top-most chain
 1603      * element.  We therefore temporarily push a NULL cert onto the chain if it
 1604      * was verified via a bare public key, and pop it off right after the
 1605      * X509_policy_check() call.
 1606      */
 1607     if (ctx->bare_ta_signed && !sk_X509_push(ctx->chain, NULL)) {
 1608         X509err(X509_F_CHECK_POLICY, ERR_R_MALLOC_FAILURE);
 1609         ctx->error = X509_V_ERR_OUT_OF_MEM;
 1610         return 0;
 1611     }
 1612     ret = X509_policy_check(&ctx->tree, &ctx->explicit_policy, ctx->chain,
 1613                             ctx->param->policies, ctx->param->flags);
 1614     if (ctx->bare_ta_signed)
 1615         sk_X509_pop(ctx->chain);
 1616 
 1617     if (ret == X509_PCY_TREE_INTERNAL) {
 1618         X509err(X509_F_CHECK_POLICY, ERR_R_MALLOC_FAILURE);
 1619         ctx->error = X509_V_ERR_OUT_OF_MEM;
 1620         return 0;
 1621     }
 1622     /* Invalid or inconsistent extensions */
 1623     if (ret == X509_PCY_TREE_INVALID) {
 1624         int i;
 1625 
 1626         /* Locate certificates with bad extensions and notify callback. */
 1627         for (i = 1; i < sk_X509_num(ctx->chain); i++) {
 1628             X509 *x = sk_X509_value(ctx->chain, i);
 1629 
 1630             if (!(x->ex_flags & EXFLAG_INVALID_POLICY))
 1631                 continue;
 1632             if (!verify_cb_cert(ctx, x, i,
 1633                                 X509_V_ERR_INVALID_POLICY_EXTENSION))
 1634                 return 0;
 1635         }
 1636         return 1;
 1637     }
 1638     if (ret == X509_PCY_TREE_FAILURE) {
 1639         ctx->current_cert = NULL;
 1640         ctx->error = X509_V_ERR_NO_EXPLICIT_POLICY;
 1641         return ctx->verify_cb(0, ctx);
 1642     }
 1643     if (ret != X509_PCY_TREE_VALID) {
 1644         X509err(X509_F_CHECK_POLICY, ERR_R_INTERNAL_ERROR);
 1645         return 0;
 1646     }
 1647 
 1648     if (ctx->param->flags & X509_V_FLAG_NOTIFY_POLICY) {
 1649         ctx->current_cert = NULL;
 1650         /*
 1651          * Verification errors need to be "sticky", a callback may have allowed
 1652          * an SSL handshake to continue despite an error, and we must then
 1653          * remain in an error state.  Therefore, we MUST NOT clear earlier
 1654          * verification errors by setting the error to X509_V_OK.
 1655          */
 1656         if (!ctx->verify_cb(2, ctx))
 1657             return 0;
 1658     }
 1659 
 1660     return 1;
 1661 }
 1662 
 1663 /*-
 1664  * Check certificate validity times.
 1665  * If depth >= 0, invoke verification callbacks on error, otherwise just return
 1666  * the validation status.
 1667  *
 1668  * Return 1 on success, 0 otherwise.
 1669  */
 1670 int x509_check_cert_time(X509_STORE_CTX *ctx, X509 *x, int depth)
 1671 {
 1672     time_t *ptime;
 1673     int i;
 1674 
 1675     if (ctx->param->flags & X509_V_FLAG_USE_CHECK_TIME)
 1676         ptime = &ctx->param->check_time;
 1677     else if (ctx->param->flags & X509_V_FLAG_NO_CHECK_TIME)
 1678         return 1;
 1679     else
 1680         ptime = NULL;
 1681 
 1682     i = X509_cmp_time(X509_get0_notBefore(x), ptime);
 1683     if (i >= 0 && depth < 0)
 1684         return 0;
 1685     if (i == 0 && !verify_cb_cert(ctx, x, depth,
 1686                                   X509_V_ERR_ERROR_IN_CERT_NOT_BEFORE_FIELD))
 1687         return 0;
 1688     if (i > 0 && !verify_cb_cert(ctx, x, depth, X509_V_ERR_CERT_NOT_YET_VALID))
 1689         return 0;
 1690 
 1691     i = X509_cmp_time(X509_get0_notAfter(x), ptime);
 1692     if (i <= 0 && depth < 0)
 1693         return 0;
 1694     if (i == 0 && !verify_cb_cert(ctx, x, depth,
 1695                                   X509_V_ERR_ERROR_IN_CERT_NOT_AFTER_FIELD))
 1696         return 0;
 1697     if (i < 0 && !verify_cb_cert(ctx, x, depth, X509_V_ERR_CERT_HAS_EXPIRED))
 1698         return 0;
 1699     return 1;
 1700 }
 1701 
 1702 static int internal_verify(X509_STORE_CTX *ctx)
 1703 {
 1704     int n = sk_X509_num(ctx->chain) - 1;
 1705     X509 *xi = sk_X509_value(ctx->chain, n);
 1706     X509 *xs;
 1707 
 1708     /*
 1709      * With DANE-verified bare public key TA signatures, it remains only to
 1710      * check the timestamps of the top certificate.  We report the issuer as
 1711      * NULL, since all we have is a bare key.
 1712      */
 1713     if (ctx->bare_ta_signed) {
 1714         xs = xi;
 1715         xi = NULL;
 1716         goto check_cert;
 1717     }
 1718 
 1719     if (ctx->check_issued(ctx, xi, xi))
 1720         xs = xi;
 1721     else {
 1722         if (ctx->param->flags & X509_V_FLAG_PARTIAL_CHAIN) {
 1723             xs = xi;
 1724             goto check_cert;
 1725         }
 1726         if (n <= 0)
 1727             return verify_cb_cert(ctx, xi, 0,
 1728                                   X509_V_ERR_UNABLE_TO_VERIFY_LEAF_SIGNATURE);
 1729         n--;
 1730         ctx->error_depth = n;
 1731         xs = sk_X509_value(ctx->chain, n);
 1732     }
 1733 
 1734     /*
 1735      * Do not clear ctx->error=0, it must be "sticky", only the user's callback
 1736      * is allowed to reset errors (at its own peril).
 1737      */
 1738     while (n >= 0) {
 1739         EVP_PKEY *pkey;
 1740 
 1741         /*
 1742          * Skip signature check for self signed certificates unless explicitly
 1743          * asked for.  It doesn't add any security and just wastes time.  If
 1744          * the issuer's public key is unusable, report the issuer certificate
 1745          * and its depth (rather than the depth of the subject).
 1746          */
 1747         if (xs != xi || (ctx->param->flags & X509_V_FLAG_CHECK_SS_SIGNATURE)) {
 1748             if ((pkey = X509_get0_pubkey(xi)) == NULL) {
 1749                 if (!verify_cb_cert(ctx, xi, xi != xs ? n+1 : n,
 1750                         X509_V_ERR_UNABLE_TO_DECODE_ISSUER_PUBLIC_KEY))
 1751                     return 0;
 1752             } else if (X509_verify(xs, pkey) <= 0) {
 1753                 if (!verify_cb_cert(ctx, xs, n,
 1754                                     X509_V_ERR_CERT_SIGNATURE_FAILURE))
 1755                     return 0;
 1756             }
 1757         }
 1758 
 1759  check_cert:
 1760         /* Calls verify callback as needed */
 1761         if (!x509_check_cert_time(ctx, xs, n))
 1762             return 0;
 1763 
 1764         /*
 1765          * Signal success at this depth.  However, the previous error (if any)
 1766          * is retained.
 1767          */
 1768         ctx->current_issuer = xi;
 1769         ctx->current_cert = xs;
 1770         ctx->error_depth = n;
 1771         if (!ctx->verify_cb(1, ctx))
 1772             return 0;
 1773 
 1774         if (--n >= 0) {
 1775             xi = xs;
 1776             xs = sk_X509_value(ctx->chain, n);
 1777         }
 1778     }
 1779     return 1;
 1780 }
 1781 
 1782 int X509_cmp_current_time(const ASN1_TIME *ctm)
 1783 {
 1784     return X509_cmp_time(ctm, NULL);
 1785 }
 1786 
 1787 int X509_cmp_time(const ASN1_TIME *ctm, time_t *cmp_time)
 1788 {
 1789     static const size_t utctime_length = sizeof("YYMMDDHHMMSSZ") - 1;
 1790     static const size_t generalizedtime_length = sizeof("YYYYMMDDHHMMSSZ") - 1;
 1791     ASN1_TIME *asn1_cmp_time = NULL;
 1792     int i, day, sec, ret = 0;
 1793 #ifdef CHARSET_EBCDIC
 1794     const char upper_z = 0x5A;
 1795 #else
 1796     const char upper_z = 'Z';
 1797 #endif
 1798     /*
 1799      * Note that ASN.1 allows much more slack in the time format than RFC5280.
 1800      * In RFC5280, the representation is fixed:
 1801      * UTCTime: YYMMDDHHMMSSZ
 1802      * GeneralizedTime: YYYYMMDDHHMMSSZ
 1803      *
 1804      * We do NOT currently enforce the following RFC 5280 requirement:
 1805      * "CAs conforming to this profile MUST always encode certificate
 1806      *  validity dates through the year 2049 as UTCTime; certificate validity
 1807      *  dates in 2050 or later MUST be encoded as GeneralizedTime."
 1808      */
 1809     switch (ctm->type) {
 1810     case V_ASN1_UTCTIME:
 1811         if (ctm->length != (int)(utctime_length))
 1812             return 0;
 1813         break;
 1814     case V_ASN1_GENERALIZEDTIME:
 1815         if (ctm->length != (int)(generalizedtime_length))
 1816             return 0;
 1817         break;
 1818     default:
 1819         return 0;
 1820     }
 1821 
 1822     /**
 1823      * Verify the format: the ASN.1 functions we use below allow a more
 1824      * flexible format than what's mandated by RFC 5280.
 1825      * Digit and date ranges will be verified in the conversion methods.
 1826      */
 1827     for (i = 0; i < ctm->length - 1; i++) {
 1828         if (!ascii_isdigit(ctm->data[i]))
 1829             return 0;
 1830     }
 1831     if (ctm->data[ctm->length - 1] != upper_z)
 1832         return 0;
 1833 
 1834     /*
 1835      * There is ASN1_UTCTIME_cmp_time_t but no
 1836      * ASN1_GENERALIZEDTIME_cmp_time_t or ASN1_TIME_cmp_time_t,
 1837      * so we go through ASN.1
 1838      */
 1839     asn1_cmp_time = X509_time_adj(NULL, 0, cmp_time);
 1840     if (asn1_cmp_time == NULL)
 1841         goto err;
 1842     if (!ASN1_TIME_diff(&day, &sec, ctm, asn1_cmp_time))
 1843         goto err;
 1844 
 1845     /*
 1846      * X509_cmp_time comparison is <=.
 1847      * The return value 0 is reserved for errors.
 1848      */
 1849     ret = (day >= 0 && sec >= 0) ? -1 : 1;
 1850 
 1851  err:
 1852     ASN1_TIME_free(asn1_cmp_time);
 1853     return ret;
 1854 }
 1855 
 1856 ASN1_TIME *X509_gmtime_adj(ASN1_TIME *s, long adj)
 1857 {
 1858     return X509_time_adj(s, adj, NULL);
 1859 }
 1860 
 1861 ASN1_TIME *X509_time_adj(ASN1_TIME *s, long offset_sec, time_t *in_tm)
 1862 {
 1863     return X509_time_adj_ex(s, 0, offset_sec, in_tm);
 1864 }
 1865 
 1866 ASN1_TIME *X509_time_adj_ex(ASN1_TIME *s,
 1867                             int offset_day, long offset_sec, time_t *in_tm)
 1868 {
 1869     time_t t;
 1870 
 1871     if (in_tm)
 1872         t = *in_tm;
 1873     else
 1874         time(&t);
 1875 
 1876     if (s && !(s->flags & ASN1_STRING_FLAG_MSTRING)) {
 1877         if (s->type == V_ASN1_UTCTIME)
 1878             return ASN1_UTCTIME_adj(s, t, offset_day, offset_sec);
 1879         if (s->type == V_ASN1_GENERALIZEDTIME)
 1880             return ASN1_GENERALIZEDTIME_adj(s, t, offset_day, offset_sec);
 1881     }
 1882     return ASN1_TIME_adj(s, t, offset_day, offset_sec);
 1883 }
 1884 
 1885 int X509_get_pubkey_parameters(EVP_PKEY *pkey, STACK_OF(X509) *chain)
 1886 {
 1887     EVP_PKEY *ktmp = NULL, *ktmp2;
 1888     int i, j;
 1889 
 1890     if ((pkey != NULL) && !EVP_PKEY_missing_parameters(pkey))
 1891         return 1;
 1892 
 1893     for (i = 0; i < sk_X509_num(chain); i++) {
 1894         ktmp = X509_get0_pubkey(sk_X509_value(chain, i));
 1895         if (ktmp == NULL) {
 1896             X509err(X509_F_X509_GET_PUBKEY_PARAMETERS,
 1897                     X509_R_UNABLE_TO_GET_CERTS_PUBLIC_KEY);
 1898             return 0;
 1899         }
 1900         if (!EVP_PKEY_missing_parameters(ktmp))
 1901             break;
 1902     }
 1903     if (ktmp == NULL) {
 1904         X509err(X509_F_X509_GET_PUBKEY_PARAMETERS,
 1905                 X509_R_UNABLE_TO_FIND_PARAMETERS_IN_CHAIN);
 1906         return 0;
 1907     }
 1908 
 1909     /* first, populate the other certs */
 1910     for (j = i - 1; j >= 0; j--) {
 1911         ktmp2 = X509_get0_pubkey(sk_X509_value(chain, j));
 1912         EVP_PKEY_copy_parameters(ktmp2, ktmp);
 1913     }
 1914 
 1915     if (pkey != NULL)
 1916         EVP_PKEY_copy_parameters(pkey, ktmp);
 1917     return 1;
 1918 }
 1919 
 1920 /* Make a delta CRL as the diff between two full CRLs */
 1921 
 1922 X509_CRL *X509_CRL_diff(X509_CRL *base, X509_CRL *newer,
 1923                         EVP_PKEY *skey, const EVP_MD *md, unsigned int flags)
 1924 {
 1925     X509_CRL *crl = NULL;
 1926     int i;
 1927     STACK_OF(X509_REVOKED) *revs = NULL;
 1928     /* CRLs can't be delta already */
 1929     if (base->base_crl_number || newer->base_crl_number) {
 1930         X509err(X509_F_X509_CRL_DIFF, X509_R_CRL_ALREADY_DELTA);
 1931         return NULL;
 1932     }
 1933     /* Base and new CRL must have a CRL number */
 1934     if (!base->crl_number || !newer->crl_number) {
 1935         X509err(X509_F_X509_CRL_DIFF, X509_R_NO_CRL_NUMBER);
 1936         return NULL;
 1937     }
 1938     /* Issuer names must match */
 1939     if (X509_NAME_cmp(X509_CRL_get_issuer(base), X509_CRL_get_issuer(newer))) {
 1940         X509err(X509_F_X509_CRL_DIFF, X509_R_ISSUER_MISMATCH);
 1941         return NULL;
 1942     }
 1943     /* AKID and IDP must match */
 1944     if (!crl_extension_match(base, newer, NID_authority_key_identifier)) {
 1945         X509err(X509_F_X509_CRL_DIFF, X509_R_AKID_MISMATCH);
 1946         return NULL;
 1947     }
 1948     if (!crl_extension_match(base, newer, NID_issuing_distribution_point)) {
 1949         X509err(X509_F_X509_CRL_DIFF, X509_R_IDP_MISMATCH);
 1950         return NULL;
 1951     }
 1952     /* Newer CRL number must exceed full CRL number */
 1953     if (ASN1_INTEGER_cmp(newer->crl_number, base->crl_number) <= 0) {
 1954         X509err(X509_F_X509_CRL_DIFF, X509_R_NEWER_CRL_NOT_NEWER);
 1955         return NULL;
 1956     }
 1957     /* CRLs must verify */
 1958     if (skey && (X509_CRL_verify(base, skey) <= 0 ||
 1959                  X509_CRL_verify(newer, skey) <= 0)) {
 1960         X509err(X509_F_X509_CRL_DIFF, X509_R_CRL_VERIFY_FAILURE);
 1961         return NULL;
 1962     }
 1963     /* Create new CRL */
 1964     crl = X509_CRL_new();
 1965     if (crl == NULL || !X509_CRL_set_version(crl, 1))
 1966         goto memerr;
 1967     /* Set issuer name */
 1968     if (!X509_CRL_set_issuer_name(crl, X509_CRL_get_issuer(newer)))
 1969         goto memerr;
 1970 
 1971     if (!X509_CRL_set1_lastUpdate(crl, X509_CRL_get0_lastUpdate(newer)))
 1972         goto memerr;
 1973     if (!X509_CRL_set1_nextUpdate(crl, X509_CRL_get0_nextUpdate(newer)))
 1974         goto memerr;
 1975 
 1976     /* Set base CRL number: must be critical */
 1977 
 1978     if (!X509_CRL_add1_ext_i2d(crl, NID_delta_crl, base->crl_number, 1, 0))
 1979         goto memerr;
 1980 
 1981     /*
 1982      * Copy extensions across from newest CRL to delta: this will set CRL
 1983      * number to correct value too.
 1984      */
 1985 
 1986     for (i = 0; i < X509_CRL_get_ext_count(newer); i++) {
 1987         X509_EXTENSION *ext;
 1988         ext = X509_CRL_get_ext(newer, i);
 1989         if (!X509_CRL_add_ext(crl, ext, -1))
 1990             goto memerr;
 1991     }
 1992 
 1993     /* Go through revoked entries, copying as needed */
 1994 
 1995     revs = X509_CRL_get_REVOKED(newer);
 1996 
 1997     for (i = 0; i < sk_X509_REVOKED_num(revs); i++) {
 1998         X509_REVOKED *rvn, *rvtmp;
 1999         rvn = sk_X509_REVOKED_value(revs, i);
 2000         /*
 2001          * Add only if not also in base. TODO: need something cleverer here
 2002          * for some more complex CRLs covering multiple CAs.
 2003          */
 2004         if (!X509_CRL_get0_by_serial(base, &rvtmp, &rvn->serialNumber)) {
 2005             rvtmp = X509_REVOKED_dup(rvn);
 2006             if (!rvtmp)
 2007                 goto memerr;
 2008             if (!X509_CRL_add0_revoked(crl, rvtmp)) {
 2009                 X509_REVOKED_free(rvtmp);
 2010                 goto memerr;
 2011             }
 2012         }
 2013     }
 2014     /* TODO: optionally prune deleted entries */
 2015 
 2016     if (skey && md && !X509_CRL_sign(crl, skey, md))
 2017         goto memerr;
 2018 
 2019     return crl;
 2020 
 2021  memerr:
 2022     X509err(X509_F_X509_CRL_DIFF, ERR_R_MALLOC_FAILURE);
 2023     X509_CRL_free(crl);
 2024     return NULL;
 2025 }
 2026 
 2027 int X509_STORE_CTX_set_ex_data(X509_STORE_CTX *ctx, int idx, void *data)
 2028 {
 2029     return CRYPTO_set_ex_data(&ctx->ex_data, idx, data);
 2030 }
 2031 
 2032 void *X509_STORE_CTX_get_ex_data(X509_STORE_CTX *ctx, int idx)
 2033 {
 2034     return CRYPTO_get_ex_data(&ctx->ex_data, idx);
 2035 }
 2036 
 2037 int X509_STORE_CTX_get_error(X509_STORE_CTX *ctx)
 2038 {
 2039     return ctx->error;
 2040 }
 2041 
 2042 void X509_STORE_CTX_set_error(X509_STORE_CTX *ctx, int err)
 2043 {
 2044     ctx->error = err;
 2045 }
 2046 
 2047 int X509_STORE_CTX_get_error_depth(X509_STORE_CTX *ctx)
 2048 {
 2049     return ctx->error_depth;
 2050 }
 2051 
 2052 void X509_STORE_CTX_set_error_depth(X509_STORE_CTX *ctx, int depth)
 2053 {
 2054     ctx->error_depth = depth;
 2055 }
 2056 
 2057 X509 *X509_STORE_CTX_get_current_cert(X509_STORE_CTX *ctx)
 2058 {
 2059     return ctx->current_cert;
 2060 }
 2061 
 2062 void X509_STORE_CTX_set_current_cert(X509_STORE_CTX *ctx, X509 *x)
 2063 {
 2064     ctx->current_cert = x;
 2065 }
 2066 
 2067 STACK_OF(X509) *X509_STORE_CTX_get0_chain(X509_STORE_CTX *ctx)
 2068 {
 2069     return ctx->chain;
 2070 }
 2071 
 2072 STACK_OF(X509) *X509_STORE_CTX_get1_chain(X509_STORE_CTX *ctx)
 2073 {
 2074     if (!ctx->chain)
 2075         return NULL;
 2076     return X509_chain_up_ref(ctx->chain);
 2077 }
 2078 
 2079 X509 *X509_STORE_CTX_get0_current_issuer(X509_STORE_CTX *ctx)
 2080 {
 2081     return ctx->current_issuer;
 2082 }
 2083 
 2084 X509_CRL *X509_STORE_CTX_get0_current_crl(X509_STORE_CTX *ctx)
 2085 {
 2086     return ctx->current_crl;
 2087 }
 2088 
 2089 X509_STORE_CTX *X509_STORE_CTX_get0_parent_ctx(X509_STORE_CTX *ctx)
 2090 {
 2091     return ctx->parent;
 2092 }
 2093 
 2094 void X509_STORE_CTX_set_cert(X509_STORE_CTX *ctx, X509 *x)
 2095 {
 2096     ctx->cert = x;
 2097 }
 2098 
 2099 void X509_STORE_CTX_set0_crls(X509_STORE_CTX *ctx, STACK_OF(X509_CRL) *sk)
 2100 {
 2101     ctx->crls = sk;
 2102 }
 2103 
 2104 int X509_STORE_CTX_set_purpose(X509_STORE_CTX *ctx, int purpose)
 2105 {
 2106     /*
 2107      * XXX: Why isn't this function always used to set the associated trust?
 2108      * Should there even be a VPM->trust field at all?  Or should the trust
 2109      * always be inferred from the purpose by X509_STORE_CTX_init().
 2110      */
 2111     return X509_STORE_CTX_purpose_inherit(ctx, 0, purpose, 0);
 2112 }
 2113 
 2114 int X509_STORE_CTX_set_trust(X509_STORE_CTX *ctx, int trust)
 2115 {
 2116     /*
 2117      * XXX: See above, this function would only be needed when the default
 2118      * trust for the purpose needs an override in a corner case.
 2119      */
 2120     return X509_STORE_CTX_purpose_inherit(ctx, 0, 0, trust);
 2121 }
 2122 
 2123 /*
 2124  * This function is used to set the X509_STORE_CTX purpose and trust values.
 2125  * This is intended to be used when another structure has its own trust and
 2126  * purpose values which (if set) will be inherited by the ctx. If they aren't
 2127  * set then we will usually have a default purpose in mind which should then
 2128  * be used to set the trust value. An example of this is SSL use: an SSL
 2129  * structure will have its own purpose and trust settings which the
 2130  * application can set: if they aren't set then we use the default of SSL
 2131  * client/server.
 2132  */
 2133 
 2134 int X509_STORE_CTX_purpose_inherit(X509_STORE_CTX *ctx, int def_purpose,
 2135                                    int purpose, int trust)
 2136 {
 2137     int idx;
 2138     /* If purpose not set use default */
 2139     if (!purpose)
 2140         purpose = def_purpose;
 2141     /* If we have a purpose then check it is valid */
 2142     if (purpose) {
 2143         X509_PURPOSE *ptmp;
 2144         idx = X509_PURPOSE_get_by_id(purpose);
 2145         if (idx == -1) {
 2146             X509err(X509_F_X509_STORE_CTX_PURPOSE_INHERIT,
 2147                     X509_R_UNKNOWN_PURPOSE_ID);
 2148             return 0;
 2149         }
 2150         ptmp = X509_PURPOSE_get0(idx);
 2151         if (ptmp->trust == X509_TRUST_DEFAULT) {
 2152             idx = X509_PURPOSE_get_by_id(def_purpose);
 2153             /*
 2154              * XXX: In the two callers above def_purpose is always 0, which is
 2155              * not a known value, so idx will always be -1.  How is the
 2156              * X509_TRUST_DEFAULT case actually supposed to be handled?
 2157              */
 2158             if (idx == -1) {
 2159                 X509err(X509_F_X509_STORE_CTX_PURPOSE_INHERIT,
 2160                         X509_R_UNKNOWN_PURPOSE_ID);
 2161                 return 0;
 2162             }
 2163             ptmp = X509_PURPOSE_get0(idx);
 2164         }
 2165         /* If trust not set then get from purpose default */
 2166         if (!trust)
 2167             trust = ptmp->trust;
 2168     }
 2169     if (trust) {
 2170         idx = X509_TRUST_get_by_id(trust);
 2171         if (idx == -1) {
 2172             X509err(X509_F_X509_STORE_CTX_PURPOSE_INHERIT,
 2173                     X509_R_UNKNOWN_TRUST_ID);
 2174             return 0;
 2175         }
 2176     }
 2177 
 2178     if (purpose && !ctx->param->purpose)
 2179         ctx->param->purpose = purpose;
 2180     if (trust && !ctx->param->trust)
 2181         ctx->param->trust = trust;
 2182     return 1;
 2183 }
 2184 
 2185 X509_STORE_CTX *X509_STORE_CTX_new(void)
 2186 {
 2187     X509_STORE_CTX *ctx = OPENSSL_zalloc(sizeof(*ctx));
 2188 
 2189     if (ctx == NULL) {
 2190         X509err(X509_F_X509_STORE_CTX_NEW, ERR_R_MALLOC_FAILURE);
 2191         return NULL;
 2192     }
 2193     return ctx;
 2194 }
 2195 
 2196 void X509_STORE_CTX_free(X509_STORE_CTX *ctx)
 2197 {
 2198     if (ctx == NULL)
 2199         return;
 2200 
 2201     X509_STORE_CTX_cleanup(ctx);
 2202     OPENSSL_free(ctx);
 2203 }
 2204 
 2205 int X509_STORE_CTX_init(X509_STORE_CTX *ctx, X509_STORE *store, X509 *x509,
 2206                         STACK_OF(X509) *chain)
 2207 {
 2208     int ret = 1;
 2209 
 2210     ctx->ctx = store;
 2211     ctx->cert = x509;
 2212     ctx->untrusted = chain;
 2213     ctx->crls = NULL;
 2214     ctx->num_untrusted = 0;
 2215     ctx->other_ctx = NULL;
 2216     ctx->valid = 0;
 2217     ctx->chain = NULL;
 2218     ctx->error = 0;
 2219     ctx->explicit_policy = 0;
 2220     ctx->error_depth = 0;
 2221     ctx->current_cert = NULL;
 2222     ctx->current_issuer = NULL;
 2223     ctx->current_crl = NULL;
 2224     ctx->current_crl_score = 0;
 2225     ctx->current_reasons = 0;
 2226     ctx->tree = NULL;
 2227     ctx->parent = NULL;
 2228     ctx->dane = NULL;
 2229     ctx->bare_ta_signed = 0;
 2230     /* Zero ex_data to make sure we're cleanup-safe */
 2231     memset(&ctx->ex_data, 0, sizeof(ctx->ex_data));
 2232 
 2233     /* store->cleanup is always 0 in OpenSSL, if set must be idempotent */
 2234     if (store)
 2235         ctx->cleanup = store->cleanup;
 2236     else
 2237         ctx->cleanup = 0;
 2238 
 2239     if (store && store->check_issued)
 2240         ctx->check_issued = store->check_issued;
 2241     else
 2242         ctx->check_issued = check_issued;
 2243 
 2244     if (store && store->get_issuer)
 2245         ctx->get_issuer = store->get_issuer;
 2246     else
 2247         ctx->get_issuer = X509_STORE_CTX_get1_issuer;
 2248 
 2249     if (store && store->verify_cb)
 2250         ctx->verify_cb = store->verify_cb;
 2251     else
 2252         ctx->verify_cb = null_callback;
 2253 
 2254     if (store && store->verify)
 2255         ctx->verify = store->verify;
 2256     else
 2257         ctx->verify = internal_verify;
 2258 
 2259     if (store && store->check_revocation)
 2260         ctx->check_revocation = store->check_revocation;
 2261     else
 2262         ctx->check_revocation = check_revocation;
 2263 
 2264     if (store && store->get_crl)
 2265         ctx->get_crl = store->get_crl;
 2266     else
 2267         ctx->get_crl = NULL;
 2268 
 2269     if (store && store->check_crl)
 2270         ctx->check_crl = store->check_crl;
 2271     else
 2272         ctx->check_crl = check_crl;
 2273 
 2274     if (store && store->cert_crl)
 2275         ctx->cert_crl = store->cert_crl;
 2276     else
 2277         ctx->cert_crl = cert_crl;
 2278 
 2279     if (store && store->check_policy)
 2280         ctx->check_policy = store->check_policy;
 2281     else
 2282         ctx->check_policy = check_policy;
 2283 
 2284     if (store && store->lookup_certs)
 2285         ctx->lookup_certs = store->lookup_certs;
 2286     else
 2287         ctx->lookup_certs = X509_STORE_CTX_get1_certs;
 2288 
 2289     if (store && store->lookup_crls)
 2290         ctx->lookup_crls = store->lookup_crls;
 2291     else
 2292         ctx->lookup_crls = X509_STORE_CTX_get1_crls;
 2293 
 2294     ctx->param = X509_VERIFY_PARAM_new();
 2295     if (ctx->param == NULL) {
 2296         X509err(X509_F_X509_STORE_CTX_INIT, ERR_R_MALLOC_FAILURE);
 2297         goto err;
 2298     }
 2299 
 2300     /*
 2301      * Inherit callbacks and flags from X509_STORE if not set use defaults.
 2302      */
 2303     if (store)
 2304         ret = X509_VERIFY_PARAM_inherit(ctx->param, store->param);
 2305     else
 2306         ctx->param->inh_flags |= X509_VP_FLAG_DEFAULT | X509_VP_FLAG_ONCE;
 2307 
 2308     if (ret)
 2309         ret = X509_VERIFY_PARAM_inherit(ctx->param,
 2310                                         X509_VERIFY_PARAM_lookup("default"));
 2311 
 2312     if (ret == 0) {
 2313         X509err(X509_F_X509_STORE_CTX_INIT, ERR_R_MALLOC_FAILURE);
 2314         goto err;
 2315     }
 2316 
 2317     /*
 2318      * XXX: For now, continue to inherit trust from VPM, but infer from the
 2319      * purpose if this still yields the default value.
 2320      */
 2321     if (ctx->param->trust == X509_TRUST_DEFAULT) {
 2322         int idx = X509_PURPOSE_get_by_id(ctx->param->purpose);
 2323         X509_PURPOSE *xp = X509_PURPOSE_get0(idx);
 2324 
 2325         if (xp != NULL)
 2326             ctx->param->trust = X509_PURPOSE_get_trust(xp);
 2327     }
 2328 
 2329     if (CRYPTO_new_ex_data(CRYPTO_EX_INDEX_X509_STORE_CTX, ctx,
 2330                            &ctx->ex_data))
 2331         return 1;
 2332     X509err(X509_F_X509_STORE_CTX_INIT, ERR_R_MALLOC_FAILURE);
 2333 
 2334  err:
 2335     /*
 2336      * On error clean up allocated storage, if the store context was not
 2337      * allocated with X509_STORE_CTX_new() this is our last chance to do so.
 2338      */
 2339     X509_STORE_CTX_cleanup(ctx);
 2340     return 0;
 2341 }
 2342 
 2343 /*
 2344  * Set alternative lookup method: just a STACK of trusted certificates. This
 2345  * avoids X509_STORE nastiness where it isn't needed.
 2346  */
 2347 void X509_STORE_CTX_set0_trusted_stack(X509_STORE_CTX *ctx, STACK_OF(X509) *sk)
 2348 {
 2349     ctx->other_ctx = sk;
 2350     ctx->get_issuer = get_issuer_sk;
 2351     ctx->lookup_certs = lookup_certs_sk;
 2352 }
 2353 
 2354 void X509_STORE_CTX_cleanup(X509_STORE_CTX *ctx)
 2355 {
 2356     /*
 2357      * We need to be idempotent because, unfortunately, free() also calls
 2358      * cleanup(), so the natural call sequence new(), init(), cleanup(), free()
 2359      * calls cleanup() for the same object twice!  Thus we must zero the
 2360      * pointers below after they're freed!
 2361      */
 2362     /* Seems to always be 0 in OpenSSL, do this at most once. */
 2363     if (ctx->cleanup != NULL) {
 2364         ctx->cleanup(ctx);
 2365         ctx->cleanup = NULL;
 2366     }
 2367     if (ctx->param != NULL) {
 2368         if (ctx->parent == NULL)
 2369             X509_VERIFY_PARAM_free(ctx->param);
 2370         ctx->param = NULL;
 2371     }
 2372     X509_policy_tree_free(ctx->tree);
 2373     ctx->tree = NULL;
 2374     sk_X509_pop_free(ctx->chain, X509_free);
 2375     ctx->chain = NULL;
 2376     CRYPTO_free_ex_data(CRYPTO_EX_INDEX_X509_STORE_CTX, ctx, &(ctx->ex_data));
 2377     memset(&ctx->ex_data, 0, sizeof(ctx->ex_data));
 2378 }
 2379 
 2380 void X509_STORE_CTX_set_depth(X509_STORE_CTX *ctx, int depth)
 2381 {
 2382     X509_VERIFY_PARAM_set_depth(ctx->param, depth);
 2383 }
 2384 
 2385 void X509_STORE_CTX_set_flags(X509_STORE_CTX *ctx, unsigned long flags)
 2386 {
 2387     X509_VERIFY_PARAM_set_flags(ctx->param, flags);
 2388 }
 2389 
 2390 void X509_STORE_CTX_set_time(X509_STORE_CTX *ctx, unsigned long flags,
 2391                              time_t t)
 2392 {
 2393     X509_VERIFY_PARAM_set_time(ctx->param, t);
 2394 }
 2395 
 2396 X509 *X509_STORE_CTX_get0_cert(X509_STORE_CTX *ctx)
 2397 {
 2398     return ctx->cert;
 2399 }
 2400 
 2401 STACK_OF(X509) *X509_STORE_CTX_get0_untrusted(X509_STORE_CTX *ctx)
 2402 {
 2403     return ctx->untrusted;
 2404 }
 2405 
 2406 void X509_STORE_CTX_set0_untrusted(X509_STORE_CTX *ctx, STACK_OF(X509) *sk)
 2407 {
 2408     ctx->untrusted = sk;
 2409 }
 2410 
 2411 void X509_STORE_CTX_set0_verified_chain(X509_STORE_CTX *ctx, STACK_OF(X509) *sk)
 2412 {
 2413     sk_X509_pop_free(ctx->chain, X509_free);
 2414     ctx->chain = sk;
 2415 }
 2416 
 2417 void X509_STORE_CTX_set_verify_cb(X509_STORE_CTX *ctx,
 2418                                   X509_STORE_CTX_verify_cb verify_cb)
 2419 {
 2420     ctx->verify_cb = verify_cb;
 2421 }
 2422 
 2423 X509_STORE_CTX_verify_cb X509_STORE_CTX_get_verify_cb(X509_STORE_CTX *ctx)
 2424 {
 2425     return ctx->verify_cb;
 2426 }
 2427 
 2428 void X509_STORE_CTX_set_verify(X509_STORE_CTX *ctx,
 2429                                X509_STORE_CTX_verify_fn verify)
 2430 {
 2431     ctx->verify = verify;
 2432 }
 2433 
 2434 X509_STORE_CTX_verify_fn X509_STORE_CTX_get_verify(X509_STORE_CTX *ctx)
 2435 {
 2436     return ctx->verify;
 2437 }
 2438 
 2439 X509_STORE_CTX_get_issuer_fn X509_STORE_CTX_get_get_issuer(X509_STORE_CTX *ctx)
 2440 {
 2441     return ctx->get_issuer;
 2442 }
 2443 
 2444 X509_STORE_CTX_check_issued_fn X509_STORE_CTX_get_check_issued(X509_STORE_CTX *ctx)
 2445 {
 2446     return ctx->check_issued;
 2447 }
 2448 
 2449 X509_STORE_CTX_check_revocation_fn X509_STORE_CTX_get_check_revocation(X509_STORE_CTX *ctx)
 2450 {
 2451     return ctx->check_revocation;
 2452 }
 2453 
 2454 X509_STORE_CTX_get_crl_fn X509_STORE_CTX_get_get_crl(X509_STORE_CTX *ctx)
 2455 {
 2456     return ctx->get_crl;
 2457 }
 2458 
 2459 X509_STORE_CTX_check_crl_fn X509_STORE_CTX_get_check_crl(X509_STORE_CTX *ctx)
 2460 {
 2461     return ctx->check_crl;
 2462 }
 2463 
 2464 X509_STORE_CTX_cert_crl_fn X509_STORE_CTX_get_cert_crl(X509_STORE_CTX *ctx)
 2465 {
 2466     return ctx->cert_crl;
 2467 }
 2468 
 2469 X509_STORE_CTX_check_policy_fn X509_STORE_CTX_get_check_policy(X509_STORE_CTX *ctx)
 2470 {
 2471     return ctx->check_policy;
 2472 }
 2473 
 2474 X509_STORE_CTX_lookup_certs_fn X509_STORE_CTX_get_lookup_certs(X509_STORE_CTX *ctx)
 2475 {
 2476     return ctx->lookup_certs;
 2477 }
 2478 
 2479 X509_STORE_CTX_lookup_crls_fn X509_STORE_CTX_get_lookup_crls(X509_STORE_CTX *ctx)
 2480 {
 2481     return ctx->lookup_crls;
 2482 }
 2483 
 2484 X509_STORE_CTX_cleanup_fn X509_STORE_CTX_get_cleanup(X509_STORE_CTX *ctx)
 2485 {
 2486     return ctx->cleanup;
 2487 }
 2488 
 2489 X509_POLICY_TREE *X509_STORE_CTX_get0_policy_tree(X509_STORE_CTX *ctx)
 2490 {
 2491     return ctx->tree;
 2492 }
 2493 
 2494 int X509_STORE_CTX_get_explicit_policy(X509_STORE_CTX *ctx)
 2495 {
 2496     return ctx->explicit_policy;
 2497 }
 2498 
 2499 int X509_STORE_CTX_get_num_untrusted(X509_STORE_CTX *ctx)
 2500 {
 2501     return ctx->num_untrusted;
 2502 }
 2503 
 2504 int X509_STORE_CTX_set_default(X509_STORE_CTX *ctx, const char *name)
 2505 {
 2506     const X509_VERIFY_PARAM *param;
 2507     param = X509_VERIFY_PARAM_lookup(name);
 2508     if (!param)
 2509         return 0;
 2510     return X509_VERIFY_PARAM_inherit(ctx->param, param);
 2511 }
 2512 
 2513 X509_VERIFY_PARAM *X509_STORE_CTX_get0_param(X509_STORE_CTX *ctx)
 2514 {
 2515     return ctx->param;
 2516 }
 2517 
 2518 void X509_STORE_CTX_set0_param(X509_STORE_CTX *ctx, X509_VERIFY_PARAM *param)
 2519 {
 2520     X509_VERIFY_PARAM_free(ctx->param);
 2521     ctx->param = param;
 2522 }
 2523 
 2524 void X509_STORE_CTX_set0_dane(X509_STORE_CTX *ctx, SSL_DANE *dane)
 2525 {
 2526     ctx->dane = dane;
 2527 }
 2528 
 2529 static unsigned char *dane_i2d(
 2530     X509 *cert,
 2531     uint8_t selector,
 2532     unsigned int *i2dlen)
 2533 {
 2534     unsigned char *buf = NULL;
 2535     int len;
 2536 
 2537     /*
 2538      * Extract ASN.1 DER form of certificate or public key.
 2539      */
 2540     switch (selector) {
 2541     case DANETLS_SELECTOR_CERT:
 2542         len = i2d_X509(cert, &buf);
 2543         break;
 2544     case DANETLS_SELECTOR_SPKI:
 2545         len = i2d_X509_PUBKEY(X509_get_X509_PUBKEY(cert), &buf);
 2546         break;
 2547     default:
 2548         X509err(X509_F_DANE_I2D, X509_R_BAD_SELECTOR);
 2549         return NULL;
 2550     }
 2551 
 2552     if (len < 0 || buf == NULL) {
 2553         X509err(X509_F_DANE_I2D, ERR_R_MALLOC_FAILURE);
 2554         return NULL;
 2555     }
 2556 
 2557     *i2dlen = (unsigned int)len;
 2558     return buf;
 2559 }
 2560 
 2561 #define DANETLS_NONE 256        /* impossible uint8_t */
 2562 
 2563 static int dane_match(X509_STORE_CTX *ctx, X509 *cert, int depth)
 2564 {
 2565     SSL_DANE *dane = ctx->dane;
 2566     unsigned usage = DANETLS_NONE;
 2567     unsigned selector = DANETLS_NONE;
 2568     unsigned ordinal = DANETLS_NONE;
 2569     unsigned mtype = DANETLS_NONE;
 2570     unsigned char *i2dbuf = NULL;
 2571     unsigned int i2dlen = 0;
 2572     unsigned char mdbuf[EVP_MAX_MD_SIZE];
 2573     unsigned char *cmpbuf = NULL;
 2574     unsigned int cmplen = 0;
 2575     int i;
 2576     int recnum;
 2577     int matched = 0;
 2578     danetls_record *t = NULL;
 2579     uint32_t mask;
 2580 
 2581     mask = (depth == 0) ? DANETLS_EE_MASK : DANETLS_TA_MASK;
 2582 
 2583     /*
 2584      * The trust store is not applicable with DANE-TA(2)
 2585      */
 2586     if (depth >= ctx->num_untrusted)
 2587         mask &= DANETLS_PKIX_MASK;
 2588 
 2589     /*
 2590      * If we've previously matched a PKIX-?? record, no need to test any
 2591      * further PKIX-?? records, it remains to just build the PKIX chain.
 2592      * Had the match been a DANE-?? record, we'd be done already.
 2593      */
 2594     if (dane->mdpth >= 0)
 2595         mask &= ~DANETLS_PKIX_MASK;
 2596 
 2597     /*-
 2598      * https://tools.ietf.org/html/rfc7671#section-5.1
 2599      * https://tools.ietf.org/html/rfc7671#section-5.2
 2600      * https://tools.ietf.org/html/rfc7671#section-5.3
 2601      * https://tools.ietf.org/html/rfc7671#section-5.4
 2602      *
 2603      * We handle DANE-EE(3) records first as they require no chain building
 2604      * and no expiration or hostname checks.  We also process digests with
 2605      * higher ordinals first and ignore lower priorities except Full(0) which
 2606      * is always processed (last).  If none match, we then process PKIX-EE(1).
 2607      *
 2608      * NOTE: This relies on DANE usages sorting before the corresponding PKIX
 2609      * usages in SSL_dane_tlsa_add(), and also on descending sorting of digest
 2610      * priorities.  See twin comment in ssl/ssl_lib.c.
 2611      *
 2612      * We expect that most TLSA RRsets will have just a single usage, so we
 2613      * don't go out of our way to cache multiple selector-specific i2d buffers
 2614      * across usages, but if the selector happens to remain the same as switch
 2615      * usages, that's OK.  Thus, a set of "3 1 1", "3 0 1", "1 1 1", "1 0 1",
 2616      * records would result in us generating each of the certificate and public
 2617      * key DER forms twice, but more typically we'd just see multiple "3 1 1"
 2618      * or multiple "3 0 1" records.
 2619      *
 2620      * As soon as we find a match at any given depth, we stop, because either
 2621      * we've matched a DANE-?? record and the peer is authenticated, or, after
 2622      * exhausting all DANE-?? records, we've matched a PKIX-?? record, which is
 2623      * sufficient for DANE, and what remains to do is ordinary PKIX validation.
 2624      */
 2625     recnum = (dane->umask & mask) ? sk_danetls_record_num(dane->trecs) : 0;
 2626     for (i = 0; matched == 0 && i < recnum; ++i) {
 2627         t = sk_danetls_record_value(dane->trecs, i);
 2628         if ((DANETLS_USAGE_BIT(t->usage) & mask) == 0)
 2629             continue;
 2630         if (t->usage != usage) {
 2631             usage = t->usage;
 2632 
 2633             /* Reset digest agility for each usage/selector pair */
 2634             mtype = DANETLS_NONE;
 2635             ordinal = dane->dctx->mdord[t->mtype];
 2636         }
 2637         if (t->selector != selector) {
 2638             selector = t->selector;
 2639 
 2640             /* Update per-selector state */
 2641             OPENSSL_free(i2dbuf);
 2642             i2dbuf = dane_i2d(cert, selector, &i2dlen);
 2643             if (i2dbuf == NULL)
 2644                 return -1;
 2645 
 2646             /* Reset digest agility for each usage/selector pair */
 2647             mtype = DANETLS_NONE;
 2648             ordinal = dane->dctx->mdord[t->mtype];
 2649         } else if (t->mtype != DANETLS_MATCHING_FULL) {
 2650             /*-
 2651              * Digest agility:
 2652              *
 2653              *     <https://tools.ietf.org/html/rfc7671#section-9>
 2654              *
 2655              * For a fixed selector, after processing all records with the
 2656              * highest mtype ordinal, ignore all mtypes with lower ordinals
 2657              * other than "Full".
 2658              */
 2659             if (dane->dctx->mdord[t->mtype] < ordinal)
 2660                 continue;
 2661         }
 2662 
 2663         /*
 2664          * Each time we hit a (new selector or) mtype, re-compute the relevant
 2665          * digest, more complex caching is not worth the code space.
 2666          */
 2667         if (t->mtype != mtype) {
 2668             const EVP_MD *md = dane->dctx->mdevp[mtype = t->mtype];
 2669             cmpbuf = i2dbuf;
 2670             cmplen = i2dlen;
 2671 
 2672             if (md != NULL) {
 2673                 cmpbuf = mdbuf;
 2674                 if (!EVP_Digest(i2dbuf, i2dlen, cmpbuf, &cmplen, md, 0)) {
 2675                     matched = -1;
 2676                     break;
 2677                 }
 2678             }
 2679         }
 2680 
 2681         /*
 2682          * Squirrel away the certificate and depth if we have a match.  Any
 2683          * DANE match is dispositive, but with PKIX we still need to build a
 2684          * full chain.
 2685          */
 2686         if (cmplen == t->dlen &&
 2687             memcmp(cmpbuf, t->data, cmplen) == 0) {
 2688             if (DANETLS_USAGE_BIT(usage) & DANETLS_DANE_MASK)
 2689                 matched = 1;
 2690             if (matched || dane->mdpth < 0) {
 2691                 dane->mdpth = depth;
 2692                 dane->mtlsa = t;
 2693                 OPENSSL_free(dane->mcert);
 2694                 dane->mcert = cert;
 2695                 X509_up_ref(cert);
 2696             }
 2697             break;
 2698         }
 2699     }
 2700 
 2701     /* Clear the one-element DER cache */
 2702     OPENSSL_free(i2dbuf);
 2703     return matched;
 2704 }
 2705 
 2706 static int check_dane_issuer(X509_STORE_CTX *ctx, int depth)
 2707 {
 2708     SSL_DANE *dane = ctx->dane;
 2709     int matched = 0;
 2710     X509 *cert;
 2711 
 2712     if (!DANETLS_HAS_TA(dane) || depth == 0)
 2713         return  X509_TRUST_UNTRUSTED;
 2714 
 2715     /*
 2716      * Record any DANE trust-anchor matches, for the first depth to test, if
 2717      * there's one at that depth. (This'll be false for length 1 chains looking
 2718      * for an exact match for the leaf certificate).
 2719      */
 2720     cert = sk_X509_value(ctx->chain, depth);
 2721     if (cert != NULL && (matched = dane_match(ctx, cert, depth)) < 0)
 2722         return  X509_TRUST_REJECTED;
 2723     if (matched > 0) {
 2724         ctx->num_untrusted = depth - 1;
 2725         return  X509_TRUST_TRUSTED;
 2726     }
 2727 
 2728     return  X509_TRUST_UNTRUSTED;
 2729 }
 2730 
 2731 static int check_dane_pkeys(X509_STORE_CTX *ctx)
 2732 {
 2733     SSL_DANE *dane = ctx->dane;
 2734     danetls_record *t;
 2735     int num = ctx->num_untrusted;
 2736     X509 *cert = sk_X509_value(ctx->chain, num - 1);
 2737     int recnum = sk_danetls_record_num(dane->trecs);
 2738     int i;
 2739 
 2740     for (i = 0; i < recnum; ++i) {
 2741         t = sk_danetls_record_value(dane->trecs, i);
 2742         if (t->usage != DANETLS_USAGE_DANE_TA ||
 2743             t->selector != DANETLS_SELECTOR_SPKI ||
 2744             t->mtype != DANETLS_MATCHING_FULL ||
 2745             X509_verify(cert, t->spki) <= 0)
 2746             continue;
 2747 
 2748         /* Clear any PKIX-?? matches that failed to extend to a full chain */
 2749         X509_free(dane->mcert);
 2750         dane->mcert = NULL;
 2751 
 2752         /* Record match via a bare TA public key */
 2753         ctx->bare_ta_signed = 1;
 2754         dane->mdpth = num - 1;
 2755         dane->mtlsa = t;
 2756 
 2757         /* Prune any excess chain certificates */
 2758         num = sk_X509_num(ctx->chain);
 2759         for (; num > ctx->num_untrusted; --num)
 2760             X509_free(sk_X509_pop(ctx->chain));
 2761 
 2762         return X509_TRUST_TRUSTED;
 2763     }
 2764 
 2765     return X509_TRUST_UNTRUSTED;
 2766 }
 2767 
 2768 static void dane_reset(SSL_DANE *dane)
 2769 {
 2770     /*
 2771      * Reset state to verify another chain, or clear after failure.
 2772      */
 2773     X509_free(dane->mcert);
 2774     dane->mcert = NULL;
 2775     dane->mtlsa = NULL;
 2776     dane->mdpth = -1;
 2777     dane->pdpth = -1;
 2778 }
 2779 
 2780 static int check_leaf_suiteb(X509_STORE_CTX *ctx, X509 *cert)
 2781 {
 2782     int err = X509_chain_check_suiteb(NULL, cert, NULL, ctx->param->flags);
 2783 
 2784     if (err == X509_V_OK)
 2785         return 1;
 2786     return verify_cb_cert(ctx, cert, 0, err);
 2787 }
 2788 
 2789 static int dane_verify(X509_STORE_CTX *ctx)
 2790 {
 2791     X509 *cert = ctx->cert;
 2792     SSL_DANE *dane = ctx->dane;
 2793     int matched;
 2794     int done;
 2795 
 2796     dane_reset(dane);
 2797 
 2798     /*-
 2799      * When testing the leaf certificate, if we match a DANE-EE(3) record,
 2800      * dane_match() returns 1 and we're done.  If however we match a PKIX-EE(1)
 2801      * record, the match depth and matching TLSA record are recorded, but the
 2802      * return value is 0, because we still need to find a PKIX trust-anchor.
 2803      * Therefore, when DANE authentication is enabled (required), we're done
 2804      * if:
 2805      *   + matched < 0, internal error.
 2806      *   + matched == 1, we matched a DANE-EE(3) record
 2807      *   + matched == 0, mdepth < 0 (no PKIX-EE match) and there are no
 2808      *     DANE-TA(2) or PKIX-TA(0) to test.
 2809      */
 2810     matched = dane_match(ctx, ctx->cert, 0);
 2811     done = matched != 0 || (!DANETLS_HAS_TA(dane) && dane->mdpth < 0);
 2812 
 2813     if (done)
 2814         X509_get_pubkey_parameters(NULL, ctx->chain);
 2815 
 2816     if (matched > 0) {
 2817         /* Callback invoked as needed */
 2818         if (!check_leaf_suiteb(ctx, cert))
 2819             return 0;
 2820         /* Callback invoked as needed */
 2821         if ((dane->flags & DANE_FLAG_NO_DANE_EE_NAMECHECKS) == 0 &&
 2822             !check_id(ctx))
 2823             return 0;
 2824         /* Bypass internal_verify(), issue depth 0 success callback */
 2825         ctx->error_depth = 0;
 2826         ctx->current_cert = cert;
 2827         return ctx->verify_cb(1, ctx);
 2828     }
 2829 
 2830     if (matched < 0) {
 2831         ctx->error_depth = 0;
 2832         ctx->current_cert = cert;
 2833         ctx->error = X509_V_ERR_OUT_OF_MEM;
 2834         return -1;
 2835     }
 2836 
 2837     if (done) {
 2838         /* Fail early, TA-based success is not possible */
 2839         if (!check_leaf_suiteb(ctx, cert))
 2840             return 0;
 2841         return verify_cb_cert(ctx, cert, 0, X509_V_ERR_DANE_NO_MATCH);
 2842     }
 2843 
 2844     /*
 2845      * Chain verification for usages 0/1/2.  TLSA record matching of depth > 0
 2846      * certificates happens in-line with building the rest of the chain.
 2847      */
 2848     return verify_chain(ctx);
 2849 }
 2850 
 2851 /* Get issuer, without duplicate suppression */
 2852 static int get_issuer(X509 **issuer, X509_STORE_CTX *ctx, X509 *cert)
 2853 {
 2854     STACK_OF(X509) *saved_chain = ctx->chain;
 2855     int ok;
 2856 
 2857     ctx->chain = NULL;
 2858     ok = ctx->get_issuer(issuer, ctx, cert);
 2859     ctx->chain = saved_chain;
 2860 
 2861     return ok;
 2862 }
 2863 
 2864 static int build_chain(X509_STORE_CTX *ctx)
 2865 {
 2866     SSL_DANE *dane = ctx->dane;
 2867     int num = sk_X509_num(ctx->chain);
 2868     X509 *cert = sk_X509_value(ctx->chain, num - 1);
 2869     int ss = cert_self_signed(cert);
 2870     STACK_OF(X509) *sktmp = NULL;
 2871     unsigned int search;
 2872     int may_trusted = 0;
 2873     int may_alternate = 0;
 2874     int trust = X509_TRUST_UNTRUSTED;
 2875     int alt_untrusted = 0;
 2876     int depth;
 2877     int ok = 0;
 2878     int i;
 2879 
 2880     /* Our chain starts with a single untrusted element. */
 2881     if (!ossl_assert(num == 1 && ctx->num_untrusted == num))  {
 2882         X509err(X509_F_BUILD_CHAIN, ERR_R_INTERNAL_ERROR);
 2883         ctx->error = X509_V_ERR_UNSPECIFIED;
 2884         return 0;
 2885     }
 2886 
 2887 #define S_DOUNTRUSTED      (1 << 0)     /* Search untrusted chain */
 2888 #define S_DOTRUSTED        (1 << 1)     /* Search trusted store */
 2889 #define S_DOALTERNATE      (1 << 2)     /* Retry with pruned alternate chain */
 2890     /*
 2891      * Set up search policy, untrusted if possible, trusted-first if enabled.
 2892      * If we're doing DANE and not doing PKIX-TA/PKIX-EE, we never look in the
 2893      * trust_store, otherwise we might look there first.  If not trusted-first,
 2894      * and alternate chains are not disabled, try building an alternate chain
 2895      * if no luck with untrusted first.
 2896      */
 2897     search = (ctx->untrusted != NULL) ? S_DOUNTRUSTED : 0;
 2898     if (DANETLS_HAS_PKIX(dane) || !DANETLS_HAS_DANE(dane)) {
 2899         if (search == 0 || ctx->param->flags & X509_V_FLAG_TRUSTED_FIRST)
 2900             search |= S_DOTRUSTED;
 2901         else if (!(ctx->param->flags & X509_V_FLAG_NO_ALT_CHAINS))
 2902             may_alternate = 1;
 2903         may_trusted = 1;
 2904     }
 2905 
 2906     /*
 2907      * Shallow-copy the stack of untrusted certificates (with TLS, this is
 2908      * typically the content of the peer's certificate message) so can make
 2909      * multiple passes over it, while free to remove elements as we go.
 2910      */
 2911     if (ctx->untrusted && (sktmp = sk_X509_dup(ctx->untrusted)) == NULL) {
 2912         X509err(X509_F_BUILD_CHAIN, ERR_R_MALLOC_FAILURE);
 2913         ctx->error = X509_V_ERR_OUT_OF_MEM;
 2914         return 0;
 2915     }
 2916 
 2917     /*
 2918      * If we got any "DANE-TA(2) Cert(0) Full(0)" trust-anchors from DNS, add
 2919      * them to our working copy of the untrusted certificate stack.  Since the
 2920      * caller of X509_STORE_CTX_init() may have provided only a leaf cert with
 2921      * no corresponding stack of untrusted certificates, we may need to create
 2922      * an empty stack first.  [ At present only the ssl library provides DANE
 2923      * support, and ssl_verify_cert_chain() always provides a non-null stack
 2924      * containing at least the leaf certificate, but we must be prepared for
 2925      * this to change. ]
 2926      */
 2927     if (DANETLS_ENABLED(dane) && dane->certs != NULL) {
 2928         if (sktmp == NULL && (sktmp = sk_X509_new_null()) == NULL) {
 2929             X509err(X509_F_BUILD_CHAIN, ERR_R_MALLOC_FAILURE);
 2930             ctx->error = X509_V_ERR_OUT_OF_MEM;
 2931             return 0;
 2932         }
 2933         for (i = 0; i < sk_X509_num(dane->certs); ++i) {
 2934             if (!sk_X509_push(sktmp, sk_X509_value(dane->certs, i))) {
 2935                 sk_X509_free(sktmp);
 2936                 X509err(X509_F_BUILD_CHAIN, ERR_R_MALLOC_FAILURE);
 2937                 ctx->error = X509_V_ERR_OUT_OF_MEM;
 2938                 return 0;
 2939             }
 2940         }
 2941     }
 2942 
 2943     /*
 2944      * Still absurdly large, but arithmetically safe, a lower hard upper bound
 2945      * might be reasonable.
 2946      */
 2947     if (ctx->param->depth > INT_MAX/2)
 2948         ctx->param->depth = INT_MAX/2;
 2949 
 2950     /*
 2951      * Try to Extend the chain until we reach an ultimately trusted issuer.
 2952      * Build chains up to one longer the limit, later fail if we hit the limit,
 2953      * with an X509_V_ERR_CERT_CHAIN_TOO_LONG error code.
 2954      */
 2955     depth = ctx->param->depth + 1;
 2956 
 2957     while (search != 0) {
 2958         X509 *x;
 2959         X509 *xtmp = NULL;
 2960 
 2961         /*
 2962          * Look in the trust store if enabled for first lookup, or we've run
 2963          * out of untrusted issuers and search here is not disabled.  When we
 2964          * reach the depth limit, we stop extending the chain, if by that point
 2965          * we've not found a trust-anchor, any trusted chain would be too long.
 2966          *
 2967          * The error reported to the application verify callback is at the
 2968          * maximal valid depth with the current certificate equal to the last
 2969          * not ultimately-trusted issuer.  For example, with verify_depth = 0,
 2970          * the callback will report errors at depth=1 when the immediate issuer
 2971          * of the leaf certificate is not a trust anchor.  No attempt will be
 2972          * made to locate an issuer for that certificate, since such a chain
 2973          * would be a-priori too long.
 2974          */
 2975         if ((search & S_DOTRUSTED) != 0) {
 2976             i = num = sk_X509_num(ctx->chain);
 2977             if ((search & S_DOALTERNATE) != 0) {
 2978                 /*
 2979                  * As high up the chain as we can, look for an alternative
 2980                  * trusted issuer of an untrusted certificate that currently
 2981                  * has an untrusted issuer.  We use the alt_untrusted variable
 2982                  * to track how far up the chain we find the first match.  It
 2983                  * is only if and when we find a match, that we prune the chain
 2984                  * and reset ctx->num_untrusted to the reduced count of
 2985                  * untrusted certificates.  While we're searching for such a
 2986                  * match (which may never be found), it is neither safe nor
 2987                  * wise to preemptively modify either the chain or
 2988                  * ctx->num_untrusted.
 2989                  *
 2990                  * Note, like ctx->num_untrusted, alt_untrusted is a count of
 2991                  * untrusted certificates, not a "depth".
 2992                  */
 2993                 i = alt_untrusted;
 2994             }
 2995             x = sk_X509_value(ctx->chain, i-1);
 2996 
 2997             ok = (depth < num) ? 0 : get_issuer(&xtmp, ctx, x);
 2998 
 2999             if (ok < 0) {
 3000                 trust = X509_TRUST_REJECTED;
 3001                 ctx->error = X509_V_ERR_STORE_LOOKUP;
 3002                 search = 0;
 3003                 continue;
 3004             }
 3005 
 3006             if (ok > 0) {
 3007                 /*
 3008                  * Alternative trusted issuer for a mid-chain untrusted cert?
 3009                  * Pop the untrusted cert's successors and retry.  We might now
 3010                  * be able to complete a valid chain via the trust store.  Note
 3011                  * that despite the current trust-store match we might still
 3012                  * fail complete the chain to a suitable trust-anchor, in which
 3013                  * case we may prune some more untrusted certificates and try
 3014                  * again.  Thus the S_DOALTERNATE bit may yet be turned on
 3015                  * again with an even shorter untrusted chain!
 3016                  *
 3017                  * If in the process we threw away our matching PKIX-TA trust
 3018                  * anchor, reset DANE trust.  We might find a suitable trusted
 3019                  * certificate among the ones from the trust store.
 3020                  */
 3021                 if ((search & S_DOALTERNATE) != 0) {
 3022                     if (!ossl_assert(num > i && i > 0 && ss == 0)) {
 3023                         X509err(X509_F_BUILD_CHAIN, ERR_R_INTERNAL_ERROR);
 3024                         X509_free(xtmp);
 3025                         trust = X509_TRUST_REJECTED;
 3026                         ctx->error = X509_V_ERR_UNSPECIFIED;
 3027                         search = 0;
 3028                         continue;
 3029                     }
 3030                     search &= ~S_DOALTERNATE;
 3031                     for (; num > i; --num)
 3032                         X509_free(sk_X509_pop(ctx->chain));
 3033                     ctx->num_untrusted = num;
 3034 
 3035                     if (DANETLS_ENABLED(dane) &&
 3036                         dane->mdpth >= ctx->num_untrusted) {
 3037                         dane->mdpth = -1;
 3038                         X509_free(dane->mcert);
 3039                         dane->mcert = NULL;
 3040                     }
 3041                     if (DANETLS_ENABLED(dane) &&
 3042                         dane->pdpth >= ctx->num_untrusted)
 3043                         dane->pdpth = -1;
 3044                 }
 3045 
 3046                 /*
 3047                  * Self-signed untrusted certificates get replaced by their
 3048                  * trusted matching issuer.  Otherwise, grow the chain.
 3049                  */
 3050                 if (ss == 0) {
 3051                     if (!sk_X509_push(ctx->chain, x = xtmp)) {
 3052                         X509_free(xtmp);
 3053                         X509err(X509_F_BUILD_CHAIN, ERR_R_MALLOC_FAILURE);
 3054                         trust = X509_TRUST_REJECTED;
 3055                         ctx->error = X509_V_ERR_OUT_OF_MEM;
 3056                         search = 0;
 3057                         continue;
 3058                     }
 3059                     ss = cert_self_signed(x);
 3060                 } else if (num == ctx->num_untrusted) {
 3061                     /*
 3062                      * We have a self-signed certificate that has the same
 3063                      * subject name (and perhaps keyid and/or serial number) as
 3064                      * a trust-anchor.  We must have an exact match to avoid
 3065                      * possible impersonation via key substitution etc.
 3066                      */
 3067                     if (X509_cmp(x, xtmp) != 0) {
 3068                         /* Self-signed untrusted mimic. */
 3069                         X509_free(xtmp);
 3070                         ok = 0;
 3071                     } else {
 3072                         X509_free(x);
 3073                         ctx->num_untrusted = --num;
 3074                         (void) sk_X509_set(ctx->chain, num, x = xtmp);
 3075                     }
 3076                 }
 3077 
 3078                 /*
 3079                  * We've added a new trusted certificate to the chain, recheck
 3080                  * trust.  If not done, and not self-signed look deeper.
 3081                  * Whether or not we're doing "trusted first", we no longer
 3082                  * look for untrusted certificates from the peer's chain.
 3083                  *
 3084                  * At this point ctx->num_trusted and num must reflect the
 3085                  * correct number of untrusted certificates, since the DANE
 3086                  * logic in check_trust() depends on distinguishing CAs from
 3087                  * "the wire" from CAs from the trust store.  In particular, the
 3088                  * certificate at depth "num" should be the new trusted
 3089                  * certificate with ctx->num_untrusted <= num.
 3090                  */
 3091                 if (ok) {
 3092                     if (!ossl_assert(ctx->num_untrusted <= num)) {
 3093                         X509err(X509_F_BUILD_CHAIN, ERR_R_INTERNAL_ERROR);
 3094                         trust = X509_TRUST_REJECTED;
 3095                         ctx->error = X509_V_ERR_UNSPECIFIED;
 3096                         search = 0;
 3097                         continue;
 3098                     }
 3099                     search &= ~S_DOUNTRUSTED;
 3100                     switch (trust = check_trust(ctx, num)) {
 3101                     case X509_TRUST_TRUSTED:
 3102                     case X509_TRUST_REJECTED:
 3103                         search = 0;
 3104                         continue;
 3105                     }
 3106                     if (ss == 0)
 3107                         continue;
 3108                 }
 3109             }
 3110 
 3111             /*
 3112              * No dispositive decision, and either self-signed or no match, if
 3113              * we were doing untrusted-first, and alt-chains are not disabled,
 3114              * do that, by repeatedly losing one untrusted element at a time,
 3115              * and trying to extend the shorted chain.
 3116              */
 3117             if ((search & S_DOUNTRUSTED) == 0) {
 3118                 /* Continue search for a trusted issuer of a shorter chain? */
 3119                 if ((search & S_DOALTERNATE) != 0 && --alt_untrusted > 0)
 3120                     continue;
 3121                 /* Still no luck and no fallbacks left? */
 3122                 if (!may_alternate || (search & S_DOALTERNATE) != 0 ||
 3123                     ctx->num_untrusted < 2)
 3124                     break;
 3125                 /* Search for a trusted issuer of a shorter chain */
 3126                 search |= S_DOALTERNATE;
 3127                 alt_untrusted = ctx->num_untrusted - 1;
 3128                 ss = 0;
 3129             }
 3130         }
 3131 
 3132         /*
 3133          * Extend chain with peer-provided certificates
 3134          */
 3135         if ((search & S_DOUNTRUSTED) != 0) {
 3136             num = sk_X509_num(ctx->chain);
 3137             if (!ossl_assert(num == ctx->num_untrusted)) {
 3138                 X509err(X509_F_BUILD_CHAIN, ERR_R_INTERNAL_ERROR);
 3139                 trust = X509_TRUST_REJECTED;
 3140                 ctx->error = X509_V_ERR_UNSPECIFIED;
 3141                 search = 0;
 3142                 continue;
 3143             }
 3144             x = sk_X509_value(ctx->chain, num-1);
 3145 
 3146             /*
 3147              * Once we run out of untrusted issuers, we stop looking for more
 3148              * and start looking only in the trust store if enabled.
 3149              */
 3150             xtmp = (ss || depth < num) ? NULL : find_issuer(ctx, sktmp, x);
 3151             if (xtmp == NULL) {
 3152                 search &= ~S_DOUNTRUSTED;
 3153                 if (may_trusted)
 3154                     search |= S_DOTRUSTED;
 3155                 continue;
 3156             }
 3157 
 3158             /* Drop this issuer from future consideration */
 3159             (void) sk_X509_delete_ptr(sktmp, xtmp);
 3160 
 3161             if (!sk_X509_push(ctx->chain, xtmp)) {
 3162                 X509err(X509_F_BUILD_CHAIN, ERR_R_MALLOC_FAILURE);
 3163                 trust = X509_TRUST_REJECTED;
 3164                 ctx->error = X509_V_ERR_OUT_OF_MEM;
 3165                 search = 0;
 3166                 continue;
 3167             }
 3168 
 3169             X509_up_ref(x = xtmp);
 3170             ++ctx->num_untrusted;
 3171             ss = cert_self_signed(xtmp);
 3172 
 3173             /*
 3174              * Check for DANE-TA trust of the topmost untrusted certificate.
 3175              */
 3176             switch (trust = check_dane_issuer(ctx, ctx->num_untrusted - 1)) {
 3177             case X509_TRUST_TRUSTED:
 3178             case X509_TRUST_REJECTED:
 3179                 search = 0;
 3180                 continue;
 3181             }
 3182         }
 3183     }
 3184     sk_X509_free(sktmp);
 3185 
 3186     /*
 3187      * Last chance to make a trusted chain, either bare DANE-TA public-key
 3188      * signers, or else direct leaf PKIX trust.
 3189      */
 3190     num = sk_X509_num(ctx->chain);
 3191     if (num <= depth) {
 3192         if (trust == X509_TRUST_UNTRUSTED && DANETLS_HAS_DANE_TA(dane))
 3193             trust = check_dane_pkeys(ctx);
 3194         if (trust == X509_TRUST_UNTRUSTED && num == ctx->num_untrusted)
 3195             trust = check_trust(ctx, num);
 3196     }
 3197 
 3198     switch (trust) {
 3199     case X509_TRUST_TRUSTED:
 3200         return 1;
 3201     case X509_TRUST_REJECTED:
 3202         /* Callback already issued */
 3203         return 0;
 3204     case X509_TRUST_UNTRUSTED:
 3205     default:
 3206         num = sk_X509_num(ctx->chain);
 3207         if (num > depth)
 3208             return verify_cb_cert(ctx, NULL, num-1,
 3209                                   X509_V_ERR_CERT_CHAIN_TOO_LONG);
 3210         if (DANETLS_ENABLED(dane) &&
 3211             (!DANETLS_HAS_PKIX(dane) || dane->pdpth >= 0))
 3212             return verify_cb_cert(ctx, NULL, num-1, X509_V_ERR_DANE_NO_MATCH);
 3213         if (ss && sk_X509_num(ctx->chain) == 1)
 3214             return verify_cb_cert(ctx, NULL, num-1,
 3215                                   X509_V_ERR_DEPTH_ZERO_SELF_SIGNED_CERT);
 3216         if (ss)
 3217             return verify_cb_cert(ctx, NULL, num-1,
 3218                                   X509_V_ERR_SELF_SIGNED_CERT_IN_CHAIN);
 3219         if (ctx->num_untrusted < num)
 3220             return verify_cb_cert(ctx, NULL, num-1,
 3221                                   X509_V_ERR_UNABLE_TO_GET_ISSUER_CERT);
 3222         return verify_cb_cert(ctx, NULL, num-1,
 3223                               X509_V_ERR_UNABLE_TO_GET_ISSUER_CERT_LOCALLY);
 3224     }
 3225 }
 3226 
 3227 static const int minbits_table[] = { 80, 112, 128, 192, 256 };
 3228 static const int NUM_AUTH_LEVELS = OSSL_NELEM(minbits_table);
 3229 
 3230 /*
 3231  * Check whether the public key of ``cert`` meets the security level of
 3232  * ``ctx``.
 3233  *
 3234  * Returns 1 on success, 0 otherwise.
 3235  */
 3236 static int check_key_level(X509_STORE_CTX *ctx, X509 *cert)
 3237 {
 3238     EVP_PKEY *pkey = X509_get0_pubkey(cert);
 3239     int level = ctx->param->auth_level;
 3240 
 3241     /*
 3242      * At security level zero, return without checking for a supported public
 3243      * key type.  Some engines support key types not understood outside the
 3244      * engine, and we only need to understand the key when enforcing a security
 3245      * floor.
 3246      */
 3247     if (level <= 0)
 3248         return 1;
 3249 
 3250     /* Unsupported or malformed keys are not secure */
 3251     if (pkey == NULL)
 3252         return 0;
 3253 
 3254     if (level > NUM_AUTH_LEVELS)
 3255         level = NUM_AUTH_LEVELS;
 3256 
 3257     return EVP_PKEY_security_bits(pkey) >= minbits_table[level - 1];
 3258 }
 3259 
 3260 /*
 3261  * Check whether the signature digest algorithm of ``cert`` meets the security
 3262  * level of ``ctx``.  Should not be checked for trust anchors (whether
 3263  * self-signed or otherwise).
 3264  *
 3265  * Returns 1 on success, 0 otherwise.
 3266  */
 3267 static int check_sig_level(X509_STORE_CTX *ctx, X509 *cert)
 3268 {
 3269     int secbits = -1;
 3270     int level = ctx->param->auth_level;
 3271 
 3272     if (level <= 0)
 3273         return 1;
 3274     if (level > NUM_AUTH_LEVELS)
 3275         level = NUM_AUTH_LEVELS;
 3276 
 3277     if (!X509_get_signature_info(cert, NULL, NULL, &secbits, NULL))
 3278         return 0;
 3279 
 3280     return secbits >= minbits_table[level - 1];
 3281 }