/*
 * Copyright (c) 1997 - 2008 Kungliga Tekniska Högskolan
 * (Royal Institute of Technology, Stockholm, Sweden).
 * All rights reserved.
 *
 * Portions Copyright (c) 2009 Apple Inc. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * 3. Neither the name of the Institute nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include "krb5_locl.h"
#include <assert.h>

static krb5_error_code
get_cred_kdc_capath(krb5_context, krb5_kdc_flags,
                    krb5_ccache, krb5_creds *, krb5_principal,
                    Ticket *, krb5_creds **, krb5_creds ***);

/*
 * Take the `body' and encode it into `padata' using the credentials
 * in `creds'.
 */

static krb5_error_code
make_pa_tgs_req(krb5_context context,
                krb5_auth_context ac,
                KDC_REQ_BODY *body,
                PA_DATA *padata,
                krb5_creds *creds)
{
    u_char *buf;
    size_t buf_size;
    size_t len = 0;
    krb5_data in_data;
    krb5_error_code ret;

    ASN1_MALLOC_ENCODE(KDC_REQ_BODY, buf, buf_size, body, &len, ret);
    if (ret)
        goto out;
    if(buf_size != len)
        krb5_abortx(context, "internal error in ASN.1 encoder");

    in_data.length = len;
    in_data.data   = buf;
    ret = _krb5_mk_req_internal(context, &ac, 0, &in_data, creds,
                                &padata->padata_value,
                                KRB5_KU_TGS_REQ_AUTH_CKSUM,
                                KRB5_KU_TGS_REQ_AUTH);
 out:
    free (buf);
    if(ret)
        return ret;
    padata->padata_type = KRB5_PADATA_TGS_REQ;
    return 0;
}

/*
 * Set the `enc-authorization-data' in `req_body' based on `authdata'
 */

static krb5_error_code
set_auth_data (krb5_context context,
               KDC_REQ_BODY *req_body,
               krb5_authdata *authdata,
               krb5_keyblock *subkey)
{
    if(authdata->len) {
        size_t len = 0, buf_size;
        unsigned char *buf;
        krb5_crypto crypto;
        krb5_error_code ret;

        ASN1_MALLOC_ENCODE(AuthorizationData, buf, buf_size, authdata,
                           &len, ret);
        if (ret)
            return ret;
        if (buf_size != len)
            krb5_abortx(context, "internal error in ASN.1 encoder");

        ALLOC(req_body->enc_authorization_data, 1);
        if (req_body->enc_authorization_data == NULL) {
            free (buf);
            krb5_set_error_message(context, ENOMEM,
                                   N_("malloc: out of memory", ""));
            return ENOMEM;
        }
        ret = krb5_crypto_init(context, subkey, 0, &crypto);
        if (ret) {
            free (buf);
            free (req_body->enc_authorization_data);
            req_body->enc_authorization_data = NULL;
            return ret;
        }
        krb5_encrypt_EncryptedData(context,
                                   crypto,
                                   KRB5_KU_TGS_REQ_AUTH_DAT_SUBKEY,
                                   buf,
                                   len,
                                   0,
                                   req_body->enc_authorization_data);
        free (buf);
        krb5_crypto_destroy(context, crypto);
    } else {
        req_body->enc_authorization_data = NULL;
    }
    return 0;
}

/*
 * Create a tgs-req in `t' with `addresses', `flags', `second_ticket'
 * (if not-NULL), `in_creds', `krbtgt', and returning the generated
 * subkey in `subkey'.
 */

static krb5_error_code
init_tgs_req (krb5_context context,
              krb5_ccache ccache,
              krb5_addresses *addresses,
              krb5_kdc_flags flags,
              Ticket *second_ticket,
              krb5_creds *in_creds,
              krb5_creds *krbtgt,
              unsigned nonce,
              const METHOD_DATA *padata,
              krb5_keyblock **subkey,
              TGS_REQ *t)
{
    krb5_auth_context ac = NULL;
    krb5_error_code ret = 0;

    memset(t, 0, sizeof(*t));
    t->pvno = 5;
    t->msg_type = krb_tgs_req;
    if (in_creds->session.keytype) {
        ALLOC_SEQ(&t->req_body.etype, 1);
        if(t->req_body.etype.val == NULL) {
            ret = ENOMEM;
            krb5_set_error_message(context, ret,
                                   N_("malloc: out of memory", ""));
            goto fail;
        }
        t->req_body.etype.val[0] = in_creds->session.keytype;
    } else {
        ret = _krb5_init_etype(context,
                               KRB5_PDU_TGS_REQUEST,
                               &t->req_body.etype.len,
                               &t->req_body.etype.val,
                               NULL);
    }
    if (ret)
        goto fail;
    t->req_body.addresses = addresses;
    t->req_body.kdc_options = flags.b;
    ret = copy_Realm(&in_creds->server->realm, &t->req_body.realm);
    if (ret)
        goto fail;
    ALLOC(t->req_body.sname, 1);
    if (t->req_body.sname == NULL) {
        ret = ENOMEM;
        krb5_set_error_message(context, ret, N_("malloc: out of memory", ""));
        goto fail;
    }

    /* some versions of some code might require that the client be
       present in TGS-REQs, but this is clearly against the spec */

    ret = copy_PrincipalName(&in_creds->server->name, t->req_body.sname);
    if (ret)
        goto fail;

    /* req_body.till should be NULL if there is no endtime specified,
       but old MIT code (like DCE secd) doesn't like that */
    ALLOC(t->req_body.till, 1);
    if(t->req_body.till == NULL){
        ret = ENOMEM;
        krb5_set_error_message(context, ret, N_("malloc: out of memory", ""));
        goto fail;
    }
    *t->req_body.till = in_creds->times.endtime;

    t->req_body.nonce = nonce;
    if(second_ticket){
        ALLOC(t->req_body.additional_tickets, 1);
        if (t->req_body.additional_tickets == NULL) {
            ret = ENOMEM;
            krb5_set_error_message(context, ret,
                                   N_("malloc: out of memory", ""));
            goto fail;
        }
        ALLOC_SEQ(t->req_body.additional_tickets, 1);
        if (t->req_body.additional_tickets->val == NULL) {
            ret = ENOMEM;
            krb5_set_error_message(context, ret,
                                   N_("malloc: out of memory", ""));
            goto fail;
        }
        ret = copy_Ticket(second_ticket, t->req_body.additional_tickets->val);
        if (ret)
            goto fail;
    }
    ALLOC(t->padata, 1);
    if (t->padata == NULL) {
        ret = ENOMEM;
        krb5_set_error_message(context, ret, N_("malloc: out of memory", ""));
        goto fail;
    }
    ALLOC_SEQ(t->padata, 1 + padata->len);
    if (t->padata->val == NULL) {
        ret = ENOMEM;
        krb5_set_error_message(context, ret, N_("malloc: out of memory", ""));
        goto fail;
    }
    {
        size_t i;
        for (i = 0; i < padata->len; i++) {
            ret = copy_PA_DATA(&padata->val[i], &t->padata->val[i + 1]);
            if (ret) {
                krb5_set_error_message(context, ret,
                                       N_("malloc: out of memory", ""));
                goto fail;
            }
        }
    }

    ret = krb5_auth_con_init(context, &ac);
    if(ret)
        goto fail;

    ret = krb5_auth_con_generatelocalsubkey(context, ac, &krbtgt->session);
    if (ret)
        goto fail;

    ret = set_auth_data (context, &t->req_body, &in_creds->authdata,
                         ac->local_subkey);
    if (ret)
        goto fail;

    ret = make_pa_tgs_req(context,
                          ac,
                          &t->req_body,
                          &t->padata->val[0],
                          krbtgt);
    if(ret)
        goto fail;

    ret = krb5_auth_con_getlocalsubkey(context, ac, subkey);
    if (ret)
        goto fail;

fail:
    if (ac)
        krb5_auth_con_free(context, ac);
    if (ret) {
        t->req_body.addresses = NULL;
        free_TGS_REQ (t);
    }
    return ret;
}

krb5_error_code
_krb5_get_krbtgt(krb5_context context,
                 krb5_ccache  id,
                 krb5_realm realm,
                 krb5_creds **cred)
{
    krb5_error_code ret;
    krb5_creds tmp_cred;

    memset(&tmp_cred, 0, sizeof(tmp_cred));

    ret = krb5_cc_get_principal(context, id, &tmp_cred.client);
    if (ret)
        return ret;

    ret = krb5_make_principal(context,
                              &tmp_cred.server,
                              realm,
                              KRB5_TGS_NAME,
                              realm,
                              NULL);
    if(ret) {
        krb5_free_principal(context, tmp_cred.client);
        return ret;
    }
    ret = krb5_get_credentials(context,
                               KRB5_GC_CACHED,
                               id,
                               &tmp_cred,
                               cred);
    krb5_free_principal(context, tmp_cred.client);
    krb5_free_principal(context, tmp_cred.server);
    if(ret)
        return ret;
    return 0;
}

/* DCE compatible decrypt proc */
static krb5_error_code KRB5_CALLCONV
decrypt_tkt_with_subkey (krb5_context context,
                         krb5_keyblock *key,
                         krb5_key_usage usage,
                         krb5_const_pointer skey,
                         krb5_kdc_rep *dec_rep)
{
    const krb5_keyblock *subkey = skey;
    krb5_error_code ret = 0;
    krb5_data data;
    size_t size;
    krb5_crypto crypto;

    assert(usage == 0);

    krb5_data_zero(&data);

    /*
     * start out with trying with subkey if we have one
     */
    if (subkey) {
        ret = krb5_crypto_init(context, subkey, 0, &crypto);
        if (ret)
            return ret;
        ret = krb5_decrypt_EncryptedData (context,
                                          crypto,
                                          KRB5_KU_TGS_REP_ENC_PART_SUB_KEY,
                                          &dec_rep->kdc_rep.enc_part,
                                          &data);
        /*
         * If the is Windows 2000 DC, we need to retry with key usage
         * 8 when doing ARCFOUR.
         */
        if (ret && subkey->keytype == ETYPE_ARCFOUR_HMAC_MD5) {
            ret = krb5_decrypt_EncryptedData(context,
                                             crypto,
                                             8,
                                             &dec_rep->kdc_rep.enc_part,
                                             &data);
        }
        krb5_crypto_destroy(context, crypto);
    }
    if (subkey == NULL || ret) {
        ret = krb5_crypto_init(context, key, 0, &crypto);
        if (ret)
            return ret;
        ret = krb5_decrypt_EncryptedData (context,
                                          crypto,
                                          KRB5_KU_TGS_REP_ENC_PART_SESSION,
                                          &dec_rep->kdc_rep.enc_part,
                                          &data);
        krb5_crypto_destroy(context, crypto);
    }
    if (ret)
        return ret;

    ret = decode_EncASRepPart(data.data,
                              data.length,
                              &dec_rep->enc_part,
                              &size);
    if (ret)
        ret = decode_EncTGSRepPart(data.data,
                                   data.length,
                                   &dec_rep->enc_part,
                                   &size);
    if (ret)
      krb5_set_error_message(context, ret,
                             N_("Failed to decode encpart in ticket", ""));
    krb5_data_free (&data);
    return ret;
}

static krb5_error_code
get_cred_kdc(krb5_context context,
             krb5_ccache id,
             krb5_kdc_flags flags,
             krb5_addresses *addresses,
             krb5_creds *in_creds,
             krb5_creds *krbtgt,
             krb5_principal impersonate_principal,
             Ticket *second_ticket,
             krb5_creds *out_creds)
{
    TGS_REQ req;
    krb5_data enc;
    krb5_data resp;
    krb5_kdc_rep rep;
    KRB_ERROR error;
    krb5_error_code ret;
    unsigned nonce;
    krb5_keyblock *subkey = NULL;
    size_t len = 0;
    Ticket second_ticket_data;
    METHOD_DATA padata;

    krb5_data_zero(&resp);
    krb5_data_zero(&enc);
    padata.val = NULL;
    padata.len = 0;

    krb5_generate_random_block(&nonce, sizeof(nonce));
    nonce &= 0xffffffff;

    if(flags.b.enc_tkt_in_skey && second_ticket == NULL){
        ret = decode_Ticket(in_creds->second_ticket.data,
                            in_creds->second_ticket.length,
                            &second_ticket_data, &len);
        if(ret)
            return ret;
        second_ticket = &second_ticket_data;
    }


    if (impersonate_principal) {
        krb5_crypto crypto;
        PA_S4U2Self self;
        krb5_data data;
        void *buf;
        size_t size = 0;

        self.name = impersonate_principal->name;
        self.realm = impersonate_principal->realm;
        self.auth = estrdup("Kerberos");

        ret = _krb5_s4u2self_to_checksumdata(context, &self, &data);
        if (ret) {
            free(self.auth);
            goto out;
        }

        ret = krb5_crypto_init(context, &krbtgt->session, 0, &crypto);
        if (ret) {
            free(self.auth);
            krb5_data_free(&data);
            goto out;
        }

        ret = krb5_create_checksum(context,
                                   crypto,
                                   KRB5_KU_OTHER_CKSUM,
                                   0,
                                   data.data,
                                   data.length,
                                   &self.cksum);
        krb5_crypto_destroy(context, crypto);
        krb5_data_free(&data);
        if (ret) {
            free(self.auth);
            goto out;
        }

        ASN1_MALLOC_ENCODE(PA_S4U2Self, buf, len, &self, &size, ret);
        free(self.auth);
        free_Checksum(&self.cksum);
        if (ret)
            goto out;
        if (len != size)
            krb5_abortx(context, "internal asn1 error");

        ret = krb5_padata_add(context, &padata, KRB5_PADATA_FOR_USER, buf, len);
        if (ret)
            goto out;
    }

    ret = init_tgs_req (context,
                        id,
                        addresses,
                        flags,
                        second_ticket,
                        in_creds,
                        krbtgt,
                        nonce,
                        &padata,
                        &subkey,
                        &req);
    if (ret)
        goto out;

    ASN1_MALLOC_ENCODE(TGS_REQ, enc.data, enc.length, &req, &len, ret);
    if (ret)
        goto out;
    if(enc.length != len)
        krb5_abortx(context, "internal error in ASN.1 encoder");

    /* don't free addresses */
    req.req_body.addresses = NULL;
    free_TGS_REQ(&req);

    /*
     * Send and receive
     */
    {
        krb5_sendto_ctx stctx;
        ret = krb5_sendto_ctx_alloc(context, &stctx);
        if (ret)
            return ret;
        krb5_sendto_ctx_set_func(stctx, _krb5_kdc_retry, NULL);

        ret = krb5_sendto_context (context, stctx, &enc,
                                   krbtgt->server->name.name_string.val[1],
                                   &resp);
        krb5_sendto_ctx_free(context, stctx);
    }
    if(ret)
        goto out;

    memset(&rep, 0, sizeof(rep));
    if(decode_TGS_REP(resp.data, resp.length, &rep.kdc_rep, &len) == 0) {
        unsigned eflags = 0;

        ret = krb5_copy_principal(context,
                                  in_creds->client,
                                  &out_creds->client);
        if(ret)
            goto out2;
        ret = krb5_copy_principal(context,
                                  in_creds->server,
                                  &out_creds->server);
        if(ret)
            goto out2;
        /* this should go someplace else */
        out_creds->times.endtime = in_creds->times.endtime;

        /* XXX should do better testing */
        if (flags.b.constrained_delegation || impersonate_principal)
            eflags |= EXTRACT_TICKET_ALLOW_CNAME_MISMATCH;

        ret = _krb5_extract_ticket(context,
                                   &rep,
                                   out_creds,
                                   &krbtgt->session,
                                   NULL,
                                   0,
                                   &krbtgt->addresses,
                                   nonce,
                                   eflags,
                                   decrypt_tkt_with_subkey,
                                   subkey);
    out2:
        krb5_free_kdc_rep(context, &rep);
    } else if(krb5_rd_error(context, &resp, &error) == 0) {
        ret = krb5_error_from_rd_error(context, &error, in_creds);
        krb5_free_error_contents(context, &error);
    } else if(resp.length > 0 && ((char*)resp.data)[0] == 4) {
        ret = KRB5KRB_AP_ERR_V4_REPLY;
        krb5_clear_error_message(context);
    } else {
        ret = KRB5KRB_AP_ERR_MSG_TYPE;
        krb5_clear_error_message(context);
    }

out:
    if (second_ticket == &second_ticket_data)
        free_Ticket(&second_ticket_data);
    free_METHOD_DATA(&padata);
    krb5_data_free(&resp);
    krb5_data_free(&enc);
    if(subkey)
        krb5_free_keyblock(context, subkey);
    return ret;

}

/*
 * same as above, just get local addresses first if the krbtgt have
 * them and the realm is not addressless
 */

static krb5_error_code
get_cred_kdc_address(krb5_context context,
                     krb5_ccache id,
                     krb5_kdc_flags flags,
                     krb5_addresses *addrs,
                     krb5_creds *in_creds,
                     krb5_creds *krbtgt,
                     krb5_principal impersonate_principal,
                     Ticket *second_ticket,
                     krb5_creds *out_creds)
{
    krb5_error_code ret;
    krb5_addresses addresses = { 0, NULL };

    /*
     * Inherit the address-ness of the krbtgt if the address is not
     * specified.
     */

    if (addrs == NULL && krbtgt->addresses.len != 0) {
        krb5_boolean noaddr;

        krb5_appdefault_boolean(context, NULL, krbtgt->server->realm,
                                "no-addresses", FALSE, &noaddr);

        if (!noaddr) {
            krb5_get_all_client_addrs(context, &addresses);
            /* XXX this sucks. */
            addrs = &addresses;
            if(addresses.len == 0)
                addrs = NULL;
        }
    }
    ret = get_cred_kdc(context, id, flags, addrs, in_creds,
                       krbtgt, impersonate_principal,
                       second_ticket, out_creds);
    krb5_free_addresses(context, &addresses);
    return ret;
}

KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
krb5_get_kdc_cred(krb5_context context,
                  krb5_ccache id,
                  krb5_kdc_flags flags,
                  krb5_addresses *addresses,
                  Ticket  *second_ticket,
                  krb5_creds *in_creds,
                  krb5_creds **out_creds
                  )
{
    krb5_error_code ret;
    krb5_creds *krbtgt;

    *out_creds = calloc(1, sizeof(**out_creds));
    if(*out_creds == NULL) {
        krb5_set_error_message(context, ENOMEM,
                               N_("malloc: out of memory", ""));
        return ENOMEM;
    }
    ret = _krb5_get_krbtgt (context,
                            id,
                            in_creds->server->realm,
                            &krbtgt);
    if(ret) {
        free(*out_creds);
        *out_creds = NULL;
        return ret;
    }
    ret = get_cred_kdc(context, id, flags, addresses,
                       in_creds, krbtgt, NULL, NULL, *out_creds);
    krb5_free_creds (context, krbtgt);
    if(ret) {
        free(*out_creds);
        *out_creds = NULL;
    }
    return ret;
}

static int
not_found(krb5_context context, krb5_const_principal p, krb5_error_code code)
{
    krb5_error_code ret;
    char *str;

    ret = krb5_unparse_name(context, p, &str);
    if(ret) {
        krb5_clear_error_message(context);
        return code;
    }
    krb5_set_error_message(context, code,
                           N_("Matching credential (%s) not found", ""), str);
    free(str);
    return code;
}

static krb5_error_code
find_cred(krb5_context context,
          krb5_ccache id,
          krb5_principal server,
          krb5_creds **tgts,
          krb5_creds *out_creds)
{
    krb5_error_code ret;
    krb5_creds mcreds;

    krb5_cc_clear_mcred(&mcreds);
    mcreds.server = server;
    ret = krb5_cc_retrieve_cred(context, id, KRB5_TC_DONT_MATCH_REALM,
                                &mcreds, out_creds);
    if(ret == 0)
        return 0;
    while(tgts && *tgts){
        if(krb5_compare_creds(context, KRB5_TC_DONT_MATCH_REALM,
                              &mcreds, *tgts)){
            ret = krb5_copy_creds_contents(context, *tgts, out_creds);
            return ret;
        }
        tgts++;
    }
    return not_found(context, server, KRB5_CC_NOTFOUND);
}

static krb5_error_code
add_cred(krb5_context context, krb5_creds const *tkt, krb5_creds ***tgts)
{
    int i;
    krb5_error_code ret;
    krb5_creds **tmp = *tgts;

    for(i = 0; tmp && tmp[i]; i++); /* XXX */
    tmp = realloc(tmp, (i+2)*sizeof(*tmp));
    if(tmp == NULL) {
        krb5_set_error_message(context, ENOMEM,
                               N_("malloc: out of memory", ""));
        return ENOMEM;
    }
    *tgts = tmp;
    ret = krb5_copy_creds(context, tkt, &tmp[i]);
    tmp[i+1] = NULL;
    return ret;
}

static krb5_error_code
get_cred_kdc_capath_worker(krb5_context context,
                           krb5_kdc_flags flags,
                           krb5_ccache ccache,
                           krb5_creds *in_creds,
                           krb5_const_realm try_realm,
                           krb5_principal impersonate_principal,
                           Ticket *second_ticket,
                           krb5_creds **out_creds,
                           krb5_creds ***ret_tgts)
{
    krb5_error_code ret;
    krb5_creds *tgt, tmp_creds;
    krb5_const_realm client_realm, server_realm;
    int ok_as_delegate = 1;

    *out_creds = NULL;

    client_realm = krb5_principal_get_realm(context, in_creds->client);
    server_realm = krb5_principal_get_realm(context, in_creds->server);
    memset(&tmp_creds, 0, sizeof(tmp_creds));
    ret = krb5_copy_principal(context, in_creds->client, &tmp_creds.client);
    if(ret)
        return ret;

    ret = krb5_make_principal(context,
                              &tmp_creds.server,
                              try_realm,
                              KRB5_TGS_NAME,
                              server_realm,
                              NULL);
    if(ret){
        krb5_free_principal(context, tmp_creds.client);
        return ret;
    }
    {
        krb5_creds tgts;

        ret = find_cred(context, ccache, tmp_creds.server,
                        *ret_tgts, &tgts);
        if(ret == 0){
            /* only allow implicit ok_as_delegate if the realm is the clients realm */
            if (strcmp(try_realm, client_realm) != 0 || strcmp(try_realm, server_realm) != 0)
                ok_as_delegate = tgts.flags.b.ok_as_delegate;

            *out_creds = calloc(1, sizeof(**out_creds));
            if(*out_creds == NULL) {
                ret = ENOMEM;
                krb5_set_error_message(context, ret,
                                       N_("malloc: out of memory", ""));
            } else {
                ret = get_cred_kdc_address(context, ccache, flags, NULL,
                                           in_creds, &tgts,
                                           impersonate_principal,
                                           second_ticket,
                                           *out_creds);
                if (ret) {
                    free (*out_creds);
                    *out_creds = NULL;
                } else if (ok_as_delegate == 0)
                    (*out_creds)->flags.b.ok_as_delegate = 0;
            }
            krb5_free_cred_contents(context, &tgts);
            krb5_free_principal(context, tmp_creds.server);
            krb5_free_principal(context, tmp_creds.client);
            return ret;
        }
    }
    if(krb5_realm_compare(context, in_creds->client, in_creds->server))
        return not_found(context, in_creds->server, KRB5_CC_NOTFOUND);

    /* XXX this can loop forever */
    while(1){
        heim_general_string tgt_inst;

        ret = get_cred_kdc_capath(context, flags, ccache, &tmp_creds,
                                  NULL, NULL, &tgt, ret_tgts);
        if(ret) {
            krb5_free_principal(context, tmp_creds.server);
            krb5_free_principal(context, tmp_creds.client);
            return ret;
        }
        /*
         * if either of the chain or the ok_as_delegate was stripped
         * by the kdc, make sure we strip it too.
         */
        if (ok_as_delegate == 0 || tgt->flags.b.ok_as_delegate == 0) {
            ok_as_delegate = 0;
            tgt->flags.b.ok_as_delegate = 0;
        }

        ret = add_cred(context, tgt, ret_tgts);
        if(ret) {
            krb5_free_principal(context, tmp_creds.server);
            krb5_free_principal(context, tmp_creds.client);
            return ret;
        }
        tgt_inst = tgt->server->name.name_string.val[1];
        if(strcmp(tgt_inst, server_realm) == 0)
            break;
        krb5_free_principal(context, tmp_creds.server);
        tmp_creds.server = NULL;
        ret = krb5_make_principal(context, &tmp_creds.server,
                                  tgt_inst, KRB5_TGS_NAME, server_realm, NULL);
        if(ret) {
            krb5_free_principal(context, tmp_creds.server);
            krb5_free_principal(context, tmp_creds.client);
            return ret;
        }
        ret = krb5_free_creds(context, tgt);
        if(ret) {
            krb5_free_principal(context, tmp_creds.server);
            krb5_free_principal(context, tmp_creds.client);
            return ret;
        }
    }

    krb5_free_principal(context, tmp_creds.server);
    krb5_free_principal(context, tmp_creds.client);
    *out_creds = calloc(1, sizeof(**out_creds));
    if(*out_creds == NULL) {
        ret = ENOMEM;
        krb5_set_error_message(context, ret, N_("malloc: out of memory", ""));
    } else {
        ret = get_cred_kdc_address (context, ccache, flags, NULL,
                                    in_creds, tgt, impersonate_principal,
                                    second_ticket, *out_creds);
        if (ret) {
            free (*out_creds);
            *out_creds = NULL;
        }
    }
    krb5_free_creds(context, tgt);
    return ret;
}

/*
get_cred(server)
        creds = cc_get_cred(server)
        if(creds) return creds
        tgt = cc_get_cred(krbtgt/server_realm@any_realm)
        if(tgt)
                return get_cred_tgt(server, tgt)
        if(client_realm == server_realm)
                return NULL
        tgt = get_cred(krbtgt/server_realm@client_realm)
        while(tgt_inst != server_realm)
                tgt = get_cred(krbtgt/server_realm@tgt_inst)
        return get_cred_tgt(server, tgt)
        */

static krb5_error_code
get_cred_kdc_capath(krb5_context context,
                    krb5_kdc_flags flags,
                    krb5_ccache ccache,
                    krb5_creds *in_creds,
                    krb5_principal impersonate_principal,
                    Ticket *second_ticket,
                    krb5_creds **out_creds,
                    krb5_creds ***ret_tgts)
{
    krb5_error_code ret;
    krb5_const_realm client_realm, server_realm, try_realm;

    client_realm = krb5_principal_get_realm(context, in_creds->client);
    server_realm = krb5_principal_get_realm(context, in_creds->server);

    try_realm = client_realm;
    ret = get_cred_kdc_capath_worker(context, flags, ccache, in_creds, try_realm,
                                     impersonate_principal, second_ticket, out_creds,
                                     ret_tgts);

    if (ret == KRB5KDC_ERR_S_PRINCIPAL_UNKNOWN) {
        try_realm = krb5_config_get_string(context, NULL, "capaths",
                                           client_realm, server_realm, NULL);

        if (try_realm != NULL && strcmp(try_realm, client_realm)) {
            ret = get_cred_kdc_capath_worker(context, flags, ccache, in_creds,
                                             try_realm, impersonate_principal,
                                             second_ticket, out_creds, ret_tgts);
        }
    }

    return ret;
}

static krb5_error_code
get_cred_kdc_referral(krb5_context context,
                      krb5_kdc_flags flags,
                      krb5_ccache ccache,
                      krb5_creds *in_creds,
                      krb5_principal impersonate_principal,
                      Ticket *second_ticket,
                      krb5_creds **out_creds,
                      krb5_creds ***ret_tgts)
{
    krb5_const_realm client_realm;
    krb5_error_code ret;
    krb5_creds tgt, referral, ticket;
    int loop = 0;
    int ok_as_delegate = 1;

    if (in_creds->server->name.name_string.len < 2 && !flags.b.canonicalize) {
        krb5_set_error_message(context, KRB5KDC_ERR_PATH_NOT_ACCEPTED,
                               N_("Name too short to do referals, skipping", ""));
        return KRB5KDC_ERR_PATH_NOT_ACCEPTED;
    }

    memset(&tgt, 0, sizeof(tgt));
    memset(&ticket, 0, sizeof(ticket));

    flags.b.canonicalize = 1;

    *out_creds = NULL;

    client_realm = krb5_principal_get_realm(context, in_creds->client);

    /* find tgt for the clients base realm */
    {
        krb5_principal tgtname;

        ret = krb5_make_principal(context, &tgtname,
                                  client_realm,
                                  KRB5_TGS_NAME,
                                  client_realm,
                                  NULL);
        if(ret)
            return ret;

        ret = find_cred(context, ccache, tgtname, *ret_tgts, &tgt);
        krb5_free_principal(context, tgtname);
        if (ret)
            return ret;
    }

    referral = *in_creds;
    ret = krb5_copy_principal(context, in_creds->server, &referral.server);
    if (ret) {
        krb5_free_cred_contents(context, &tgt);
        return ret;
    }
    ret = krb5_principal_set_realm(context, referral.server, client_realm);
    if (ret) {
        krb5_free_cred_contents(context, &tgt);
        krb5_free_principal(context, referral.server);
        return ret;
    }

    while (loop++ < 17) {
        krb5_creds **tickets;
        krb5_creds mcreds;
        char *referral_realm;

        /* Use cache if we are not doing impersonation or contrainte deleg */
        if (impersonate_principal == NULL || flags.b.constrained_delegation) {
            krb5_cc_clear_mcred(&mcreds);
            mcreds.server = referral.server;
            ret = krb5_cc_retrieve_cred(context, ccache, 0, &mcreds, &ticket);
        } else
            ret = EINVAL;

        if (ret) {
            ret = get_cred_kdc_address(context, ccache, flags, NULL,
                                       &referral, &tgt, impersonate_principal,
                                       second_ticket, &ticket);
            if (ret)
                goto out;
        }

        /* Did we get the right ticket ? */
        if (krb5_principal_compare_any_realm(context,
                                             referral.server,
                                             ticket.server))
            break;

        if (!krb5_principal_is_krbtgt(context, ticket.server)) {
            krb5_set_error_message(context, KRB5KRB_AP_ERR_NOT_US,
                                   N_("Got back an non krbtgt "
                                      "ticket referrals", ""));
            ret = KRB5KRB_AP_ERR_NOT_US;
            goto out;
        }

        referral_realm = ticket.server->name.name_string.val[1];

        /* check that there are no referrals loops */
        tickets = *ret_tgts;

        krb5_cc_clear_mcred(&mcreds);
        mcreds.server = ticket.server;

        while(tickets && *tickets){
            if(krb5_compare_creds(context,
                                  KRB5_TC_DONT_MATCH_REALM,
                                  &mcreds,
                                  *tickets))
            {
                krb5_set_error_message(context, KRB5_GET_IN_TKT_LOOP,
                                       N_("Referral from %s "
                                          "loops back to realm %s", ""),
                                       tgt.server->realm,
                                       referral_realm);
                ret = KRB5_GET_IN_TKT_LOOP;
                goto out;
            }
            tickets++;
        }

        /*
         * if either of the chain or the ok_as_delegate was stripped
         * by the kdc, make sure we strip it too.
         */

        if (ok_as_delegate == 0 || ticket.flags.b.ok_as_delegate == 0) {
            ok_as_delegate = 0;
            ticket.flags.b.ok_as_delegate = 0;
        }

        ret = add_cred(context, &ticket, ret_tgts);
        if (ret)
            goto out;

        /* try realm in the referral */
        ret = krb5_principal_set_realm(context,
                                       referral.server,
                                       referral_realm);
        krb5_free_cred_contents(context, &tgt);
        tgt = ticket;
        memset(&ticket, 0, sizeof(ticket));
        if (ret)
            goto out;
    }

    ret = krb5_copy_creds(context, &ticket, out_creds);

out:
    krb5_free_principal(context, referral.server);
    krb5_free_cred_contents(context, &tgt);
    krb5_free_cred_contents(context, &ticket);
    return ret;
}


/*
 * Glue function between referrals version and old client chasing
 * codebase.
 */

krb5_error_code
_krb5_get_cred_kdc_any(krb5_context context,
                       krb5_kdc_flags flags,
                       krb5_ccache ccache,
                       krb5_creds *in_creds,
                       krb5_principal impersonate_principal,
                       Ticket *second_ticket,
                       krb5_creds **out_creds,
                       krb5_creds ***ret_tgts)
{
    krb5_error_code ret;
    krb5_deltat offset;

    ret = krb5_cc_get_kdc_offset(context, ccache, &offset);
    if (ret) {
        context->kdc_sec_offset = offset;
        context->kdc_usec_offset = 0;
    }

    ret = get_cred_kdc_referral(context,
                                flags,
                                ccache,
                                in_creds,
                                impersonate_principal,
                                second_ticket,
                                out_creds,
                                ret_tgts);
    if (ret == 0 || flags.b.canonicalize)
        return ret;
    return get_cred_kdc_capath(context,
                                flags,
                                ccache,
                                in_creds,
                                impersonate_principal,
                                second_ticket,
                                out_creds,
                                ret_tgts);
}


KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
krb5_get_credentials_with_flags(krb5_context context,
                                krb5_flags options,
                                krb5_kdc_flags flags,
                                krb5_ccache ccache,
                                krb5_creds *in_creds,
                                krb5_creds **out_creds)
{
    krb5_error_code ret;
    krb5_creds **tgts;
    krb5_creds *res_creds;
    int i;

    if (in_creds->session.keytype) {
        ret = krb5_enctype_valid(context, in_creds->session.keytype);
        if (ret)
            return ret;
    }

    *out_creds = NULL;
    res_creds = calloc(1, sizeof(*res_creds));
    if (res_creds == NULL) {
        krb5_set_error_message(context, ENOMEM,
                               N_("malloc: out of memory", ""));
        return ENOMEM;
    }

    if (in_creds->session.keytype)
        options |= KRB5_TC_MATCH_KEYTYPE;

    /*
     * If we got a credential, check if credential is expired before
     * returning it.
     */
    ret = krb5_cc_retrieve_cred(context,
                                ccache,
                                in_creds->session.keytype ?
                                KRB5_TC_MATCH_KEYTYPE : 0,
                                in_creds, res_creds);
    /*
     * If we got a credential, check if credential is expired before
     * returning it, but only if KRB5_GC_EXPIRED_OK is not set.
     */
    if (ret == 0) {
        krb5_timestamp timeret;

        /* If expired ok, don't bother checking */
        if(options & KRB5_GC_EXPIRED_OK) {
            *out_creds = res_creds;
            return 0;
        }

        krb5_timeofday(context, &timeret);
        if(res_creds->times.endtime > timeret) {
            *out_creds = res_creds;
            return 0;
        }
        if(options & KRB5_GC_CACHED)
            krb5_cc_remove_cred(context, ccache, 0, res_creds);

    } else if(ret != KRB5_CC_END) {
        free(res_creds);
        return ret;
    }
    free(res_creds);
    if(options & KRB5_GC_CACHED)
        return not_found(context, in_creds->server, KRB5_CC_NOTFOUND);

    if(options & KRB5_GC_USER_USER)
        flags.b.enc_tkt_in_skey = 1;
    if (flags.b.enc_tkt_in_skey)
        options |= KRB5_GC_NO_STORE;

    tgts = NULL;
    ret = _krb5_get_cred_kdc_any(context, flags, ccache,
                                 in_creds, NULL, NULL, out_creds, &tgts);
    for(i = 0; tgts && tgts[i]; i++) {
        krb5_cc_store_cred(context, ccache, tgts[i]);
        krb5_free_creds(context, tgts[i]);
    }
    free(tgts);
    if(ret == 0 && (options & KRB5_GC_NO_STORE) == 0)
        krb5_cc_store_cred(context, ccache, *out_creds);
    return ret;
}

KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
krb5_get_credentials(krb5_context context,
                     krb5_flags options,
                     krb5_ccache ccache,
                     krb5_creds *in_creds,
                     krb5_creds **out_creds)
{
    krb5_kdc_flags flags;
    flags.i = 0;
    return krb5_get_credentials_with_flags(context, options, flags,
                                           ccache, in_creds, out_creds);
}

struct krb5_get_creds_opt_data {
    krb5_principal self;
    krb5_flags options;
    krb5_enctype enctype;
    Ticket *ticket;
};


KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
krb5_get_creds_opt_alloc(krb5_context context, krb5_get_creds_opt *opt)
{
    *opt = calloc(1, sizeof(**opt));
    if (*opt == NULL) {
        krb5_set_error_message(context, ENOMEM,
                               N_("malloc: out of memory", ""));
        return ENOMEM;
    }
    return 0;
}

KRB5_LIB_FUNCTION void KRB5_LIB_CALL
krb5_get_creds_opt_free(krb5_context context, krb5_get_creds_opt opt)
{
    if (opt->self)
        krb5_free_principal(context, opt->self);
    if (opt->ticket) {
        free_Ticket(opt->ticket);
        free(opt->ticket);
    }
    memset(opt, 0, sizeof(*opt));
    free(opt);
}

KRB5_LIB_FUNCTION void KRB5_LIB_CALL
krb5_get_creds_opt_set_options(krb5_context context,
                               krb5_get_creds_opt opt,
                               krb5_flags options)
{
    opt->options = options;
}

KRB5_LIB_FUNCTION void KRB5_LIB_CALL
krb5_get_creds_opt_add_options(krb5_context context,
                               krb5_get_creds_opt opt,
                               krb5_flags options)
{
    opt->options |= options;
}

KRB5_LIB_FUNCTION void KRB5_LIB_CALL
krb5_get_creds_opt_set_enctype(krb5_context context,
                               krb5_get_creds_opt opt,
                               krb5_enctype enctype)
{
    opt->enctype = enctype;
}

KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
krb5_get_creds_opt_set_impersonate(krb5_context context,
                                   krb5_get_creds_opt opt,
                                   krb5_const_principal self)
{
    if (opt->self)
        krb5_free_principal(context, opt->self);
    return krb5_copy_principal(context, self, &opt->self);
}

KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
krb5_get_creds_opt_set_ticket(krb5_context context,
                              krb5_get_creds_opt opt,
                              const Ticket *ticket)
{
    if (opt->ticket) {
        free_Ticket(opt->ticket);
        free(opt->ticket);
        opt->ticket = NULL;
    }
    if (ticket) {
        krb5_error_code ret;

        opt->ticket = malloc(sizeof(*ticket));
        if (opt->ticket == NULL) {
            krb5_set_error_message(context, ENOMEM,
                                   N_("malloc: out of memory", ""));
            return ENOMEM;
        }
        ret = copy_Ticket(ticket, opt->ticket);
        if (ret) {
            free(opt->ticket);
            opt->ticket = NULL;
            krb5_set_error_message(context, ret,
                                   N_("malloc: out of memory", ""));
            return ret;
        }
    }
    return 0;
}



KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
krb5_get_creds(krb5_context context,
               krb5_get_creds_opt opt,
               krb5_ccache ccache,
               krb5_const_principal inprinc,
               krb5_creds **out_creds)
{
    krb5_kdc_flags flags;
    krb5_flags options;
    krb5_creds in_creds;
    krb5_error_code ret;
    krb5_creds **tgts;
    krb5_creds *res_creds;
    int i;

    if (opt && opt->enctype) {
        ret = krb5_enctype_valid(context, opt->enctype);
        if (ret)
            return ret;
    }

    memset(&in_creds, 0, sizeof(in_creds));
    in_creds.server = rk_UNCONST(inprinc);

    ret = krb5_cc_get_principal(context, ccache, &in_creds.client);
    if (ret)
        return ret;

    if (opt)
        options = opt->options;
    else
        options = 0;
    flags.i = 0;

    *out_creds = NULL;
    res_creds = calloc(1, sizeof(*res_creds));
    if (res_creds == NULL) {
        krb5_free_principal(context, in_creds.client);
        krb5_set_error_message(context, ENOMEM,
                               N_("malloc: out of memory", ""));
        return ENOMEM;
    }

    if (opt && opt->enctype) {
        in_creds.session.keytype = opt->enctype;
        options |= KRB5_TC_MATCH_KEYTYPE;
    }

    /*
     * If we got a credential, check if credential is expired before
     * returning it.
     */
    ret = krb5_cc_retrieve_cred(context,
                                ccache,
                                options & KRB5_TC_MATCH_KEYTYPE,
                                &in_creds, res_creds);
    /*
     * If we got a credential, check if credential is expired before
     * returning it, but only if KRB5_GC_EXPIRED_OK is not set.
     */
    if (ret == 0) {
        krb5_timestamp timeret;

        /* If expired ok, don't bother checking */
        if(options & KRB5_GC_EXPIRED_OK) {
            *out_creds = res_creds;
            krb5_free_principal(context, in_creds.client);
            goto out;
        }

        krb5_timeofday(context, &timeret);
        if(res_creds->times.endtime > timeret) {
            *out_creds = res_creds;
            krb5_free_principal(context, in_creds.client);
            goto out;
        }
        if(options & KRB5_GC_CACHED)
            krb5_cc_remove_cred(context, ccache, 0, res_creds);

    } else if(ret != KRB5_CC_END) {
        free(res_creds);
        krb5_free_principal(context, in_creds.client);
        goto out;
    }
    free(res_creds);
    if(options & KRB5_GC_CACHED) {
        krb5_free_principal(context, in_creds.client);
        ret = not_found(context, in_creds.server, KRB5_CC_NOTFOUND);
        goto out;
    }
    if(options & KRB5_GC_USER_USER) {
        flags.b.enc_tkt_in_skey = 1;
        options |= KRB5_GC_NO_STORE;
    }
    if (options & KRB5_GC_FORWARDABLE)
        flags.b.forwardable = 1;
    if (options & KRB5_GC_NO_TRANSIT_CHECK)
        flags.b.disable_transited_check = 1;
    if (options & KRB5_GC_CONSTRAINED_DELEGATION) {
        flags.b.request_anonymous = 1; /* XXX ARGH confusion */
        flags.b.constrained_delegation = 1;
    }
    if (options & KRB5_GC_CANONICALIZE)
        flags.b.canonicalize = 1;

    tgts = NULL;
    ret = _krb5_get_cred_kdc_any(context, flags, ccache,
                                 &in_creds, opt->self, opt->ticket,
                                 out_creds, &tgts);
    krb5_free_principal(context, in_creds.client);
    for(i = 0; tgts && tgts[i]; i++) {
        krb5_cc_store_cred(context, ccache, tgts[i]);
        krb5_free_creds(context, tgts[i]);
    }
    free(tgts);
    if(ret == 0 && (options & KRB5_GC_NO_STORE) == 0)
        krb5_cc_store_cred(context, ccache, *out_creds);

 out:
    _krb5_debug(context, 5, "krb5_get_creds: ret = %d", ret);

    return ret;
}

/*
 *
 */

KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
krb5_get_renewed_creds(krb5_context context,
                       krb5_creds *creds,
                       krb5_const_principal client,
                       krb5_ccache ccache,
                       const char *in_tkt_service)
{
    krb5_error_code ret;
    krb5_kdc_flags flags;
    krb5_creds in, *template, *out = NULL;

    memset(&in, 0, sizeof(in));
    memset(creds, 0, sizeof(*creds));

    ret = krb5_copy_principal(context, client, &in.client);
    if (ret)
        return ret;

    if (in_tkt_service) {
        ret = krb5_parse_name(context, in_tkt_service, &in.server);
        if (ret) {
            krb5_free_principal(context, in.client);
            return ret;
        }
    } else {
        const char *realm = krb5_principal_get_realm(context, client);

        ret = krb5_make_principal(context, &in.server, realm, KRB5_TGS_NAME,
                                  realm, NULL);
        if (ret) {
            krb5_free_principal(context, in.client);
            return ret;
        }
    }

    flags.i = 0;
    flags.b.renewable = flags.b.renew = 1;

    /*
     * Get template from old credential cache for the same entry, if
     * this failes, no worries.
     */
    ret = krb5_get_credentials(context, KRB5_GC_CACHED, ccache, &in, &template);
    if (ret == 0) {
        flags.b.forwardable = template->flags.b.forwardable;
        flags.b.proxiable = template->flags.b.proxiable;
        krb5_free_creds (context, template);
    }

    ret = krb5_get_kdc_cred(context, ccache, flags, NULL, NULL, &in, &out);
    krb5_free_principal(context, in.client);
    krb5_free_principal(context, in.server);
    if (ret)
        return ret;

    ret = krb5_copy_creds_contents(context, out, creds);
    krb5_free_creds(context, out);

    return ret;
}