kdc/ca.c

   1 /*
   2  * Copyright (c) 2019 Kungliga Tekniska Högskolan
   3  * (Royal Institute of Technology, Stockholm, Sweden).
   4  * All rights reserved.
   5  *
   6  * Redistribution and use in source and binary forms, with or without
   7  * modification, are permitted provided that the following conditions
   8  * are met:
   9  *
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  *
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *    notice, this list of conditions and the following disclaimer in the
  15  *    documentation and/or other materials provided with the distribution.
  16  *
  17  * 3. Neither the name of the Institute nor the names of its contributors
  18  *    may be used to endorse or promote products derived from this software
  19  *    without specific prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
  22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
  25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  31  * SUCH DAMAGE.
  32  */
  33
  34 #include "kdc_locl.h"
  35 #include <hex.h>
  36 #include <rfc2459_asn1.h>
  37 #include "../lib/hx509/hx_locl.h"
  38
  39 #include <stdarg.h>
  40
  41 /*
  42  * This file implements a singular utility function `kdc_issue_certificate()'
  43  * for certificate issuance for kx509 and bx509, which takes a principal name,
  44  * an `hx509_request' resulting from parsing a CSR and possibly adding
  45  * SAN/EKU/KU extensions, the start/end times of request's authentication
  46  * method, and whether to include a full certificate chain in the result.
  47  */
  48
  49 /*
  50  * Get a configuration sub-tree for kx509 based on what's being requested and
  51  * by whom.
  52  *
  53  * We have a number of cases:
  54  *
  55  *  - default certificate (no CSR used, or no certificate extensions requested)
  56  *     - for client principals
  57  *     - for service principals
  58  *  - client certificate requested (CSR used and client-y SANs/EKUs requested)
  59  *  - server certificate requested (CSR used and server-y SANs/EKUs requested)
  60  *  - mixed client/server certificate requested (...)
  61  */
  62 static krb5_error_code
  63 get_cf(krb5_context context,
  64        const char *app_name,
  65        krb5_log_facility *logf,
  66        hx509_request req,
  67        krb5_principal cprinc,
  68        const krb5_config_binding **cf)
  69 {
  70     krb5_error_code ret = ENOTSUP;
  71     const char *realm = krb5_principal_get_realm(context, cprinc);
  72
  73     *cf = NULL;
  74     if (strcmp(app_name, "kdc") == 0)
  75         *cf = krb5_config_get_list(context, NULL, app_name, "realms", realm,
  76                                    "kx509", NULL);
  77     else
  78         *cf = krb5_config_get_list(context, NULL, app_name, "realms", realm,
  79                                    NULL);
  80     if (*cf)
  81         ret = 0;
  82     if (ret) {
  83         krb5_log_msg(context, logf, 3, NULL,
  84                      "No %s configuration for certification authority [%s] "
  85                      "realm %s -> kx509 -> ...", app_name,
  86                      strcmp(app_name, "bx509") == 0 ? "bx509" : "kx509",
  87                      realm);
  88         krb5_set_error_message(context, KRB5KDC_ERR_POLICY,
  89                 "No %s configuration for certification authority [%s] "
  90                 "realm %s -> kx509 -> ...", app_name,
  91                 strcmp(app_name, "bx509") == 0 ? "bx509" : "kx509",
  92                 realm);
  93     }
  94     return ret;
  95 }
  96
  97 /*
  98  * Build a certifate for `principal' and its CSR.
  99  */
 100 KDC_LIB_FUNCTION krb5_error_code KDC_LIB_CALL
 101 kdc_issue_certificate(krb5_context context,
 102                       const char *app_name,
 103                       krb5_log_facility *logf,
 104                       hx509_request req,
 105                       krb5_principal cprinc,
 106                       krb5_times *auth_times,
 107                       time_t req_life,
 108                       int send_chain,
 109                       hx509_certs *out)
 110 {
 111     const krb5_config_binding *cf;
 112     krb5_error_code ret = KRB5KDC_ERR_POLICY;
 113     KRB5PrincipalName cprinc2;
 114
 115     *out = NULL;
 116     cprinc2.principalName = cprinc->name;
 117     cprinc2.realm = cprinc->realm;
 118
 119     /* Get configuration */
 120     ret = get_cf(context, app_name, logf, req, cprinc, &cf);
 121     if (ret == 0)
 122         ret = _hx509_ca_issue_certificate(context->hx509ctx,
 123                                           (const heim_config_binding *)cf,
 124                                           logf, req, &cprinc2,
 125                                           auth_times->starttime,
 126                                           auth_times->endtime,
 127                                           req_life,
 128                                           send_chain,
 129                                           out);
 130     if (ret == EACCES)
 131         ret = KRB5KDC_ERR_POLICY;
 132     return (ret == EACCES) ? KRB5KDC_ERR_POLICY : ret;
 133 }