/* $NetBSD: get_cred.c,v 1.3.8.1 2023/08/11 13:40:01 martin Exp $ */ /* * 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 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); return krb5_enomem(context); } 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 = krb5_enomem(context); 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; t->req_body.kdc_options.forwardable = krbtgt->flags.b.forwardable; t->req_body.kdc_options.renewable = krbtgt->flags.b.renewable; t->req_body.kdc_options.proxiable = krbtgt->flags.b.proxiable; 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 = krb5_enomem(context); 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; if (krbtgt->times.starttime) { ALLOC(t->req_body.from, 1); if(t->req_body.from == NULL){ ret = krb5_enomem(context); goto fail; } *t->req_body.from = in_creds->times.starttime; } /* 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 = krb5_enomem(context); goto fail; } *t->req_body.till = in_creds->times.endtime; if (t->req_body.kdc_options.renewable && krbtgt->times.renew_till) { ALLOC(t->req_body.rtime, 1); if(t->req_body.rtime == NULL){ ret = krb5_enomem(context); goto fail; } *t->req_body.rtime = in_creds->times.renew_till; } t->req_body.nonce = nonce; if(second_ticket){ ALLOC(t->req_body.additional_tickets, 1); if (t->req_body.additional_tickets == NULL) { ret = krb5_enomem(context); goto fail; } ALLOC_SEQ(t->req_body.additional_tickets, 1); if (t->req_body.additional_tickets->val == NULL) { ret = krb5_enomem(context); 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 = krb5_enomem(context); goto fail; } ALLOC_SEQ(t->padata, 1 + padata->len); if (t->padata->val == NULL) { ret = krb5_enomem(context); 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_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL _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; } /* * The forwardable TGT might not be the start TGT, in which case, it is * generally, but not always already cached. Just in case, get it again if * lost. */ ret = krb5_get_credentials(context, 0, 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 = {0}; 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; 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.cname_in_addl_tkt || impersonate_principal) eflags |= EXTRACT_TICKET_ALLOW_CNAME_MISMATCH; if (flags.b.request_anonymous) eflags |= EXTRACT_TICKET_MATCH_ANON; ret = _krb5_extract_ticket(context, &rep, out_creds, &krbtgt->session, NULL, 0, &krbtgt->addresses, nonce, eflags, NULL, 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) return krb5_enomem(context); 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; const char *err; char *str; err = krb5_get_error_message(context, code); ret = krb5_unparse_name(context, p, &str); if(ret) { krb5_clear_error_message(context); return code; } krb5_set_error_message(context, code, N_("%s (%s)", ""), err, 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; krb5_timeofday(context, &mcreds.times.endtime); ret = krb5_cc_retrieve_cred(context, id, KRB5_TC_DONT_MATCH_REALM | KRB5_TC_MATCH_TIMES, &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) return krb5_enomem(context); *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 = NULL; krb5_creds tmp_creds; krb5_const_realm client_realm, server_realm; int ok_as_delegate = 1; *out_creds = calloc(1, sizeof(**out_creds)); if (*out_creds == NULL) return krb5_enomem(context); memset(&tmp_creds, 0, sizeof(tmp_creds)); client_realm = krb5_principal_get_realm(context, in_creds->client); server_realm = krb5_principal_get_realm(context, in_creds->server); ret = krb5_copy_principal(context, in_creds->client, &tmp_creds.client); if (ret) goto out; ret = krb5_make_principal(context, &tmp_creds.server, try_realm, KRB5_TGS_NAME, server_realm, NULL); if (ret) goto out; { krb5_creds tgts; /* * If we have krbtgt/server_realm@try_realm cached, use it and we're * done. */ 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; } ret = get_cred_kdc_address(context, ccache, flags, NULL, in_creds, &tgts, impersonate_principal, second_ticket, *out_creds); krb5_free_cred_contents(context, &tgts); if (ret == 0 && !krb5_principal_compare(context, in_creds->server, (*out_creds)->server)) { ret = KRB5KDC_ERR_S_PRINCIPAL_UNKNOWN; } if (ret == 0 && ok_as_delegate == 0) (*out_creds)->flags.b.ok_as_delegate = 0; goto out; } } if (krb5_realm_compare(context, in_creds->client, in_creds->server)) { ret = not_found(context, in_creds->server, KRB5_CC_NOTFOUND); goto out; } /* * XXX This can loop forever, plus we recurse, so we can't just keep a * count here. The count would have to get passed around by reference. * * The KDCs check for transit loops for us, and capath data is finite, so * in fact we'll fall out of this loop at some point. We should do our own * transit loop checking (like get_cred_kdc_referral()), and we should * impose a max number of iterations altogether. But barring malicious or * broken KDCs, this is good enough. */ while (1) { heim_general_string tgt_inst; ret = get_cred_kdc_capath(context, flags, ccache, &tmp_creds, NULL, NULL, &tgt, ret_tgts); if (ret) goto out; /* * 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) goto out; 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) goto out; ret = krb5_free_creds(context, tgt); tgt = NULL; if (ret) goto out; } ret = get_cred_kdc_address(context, ccache, flags, NULL, in_creds, tgt, impersonate_principal, second_ticket, *out_creds); if (ret == 0 && !krb5_principal_compare(context, in_creds->server, (*out_creds)->server)) { krb5_free_cred_contents(context, *out_creds); ret = KRB5KDC_ERR_S_PRINCIPAL_UNKNOWN; } if (ret == 0 && ok_as_delegate == 0) (*out_creds)->flags.b.ok_as_delegate = 0; out: if (ret) { krb5_free_creds(context, *out_creds); *out_creds = NULL; } if (tmp_creds.server) krb5_free_principal(context, tmp_creds.server); if (tmp_creds.client) krb5_free_principal(context, tmp_creds.client); if (tgt) 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; } /* * Get a service ticket from a KDC by chasing referrals from a start realm. * * All referral TGTs produced in the process are thrown away when we're done. * We don't store them, and we don't allow other search mechanisms (capaths) to * use referral TGTs produced here. */ 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_realm start_realm = NULL; krb5_data config_start_realm; krb5_error_code ret; krb5_creds tgt, referral, ticket; krb5_creds **referral_tgts = NULL; /* used for loop detection */ int loop = 0; int ok_as_delegate = 1; size_t i; 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; ret = krb5_cc_get_config(context, ccache, NULL, "start_realm", &config_start_realm); if (ret == 0) { start_realm = strndup(config_start_realm.data, config_start_realm.length); krb5_data_free(&config_start_realm); } else { start_realm = strdup(krb5_principal_get_realm(context, in_creds->client)); } if (start_realm == NULL) return krb5_enomem(context); /* find tgt for the clients base realm */ { krb5_principal tgtname; ret = krb5_make_principal(context, &tgtname, start_realm, KRB5_TGS_NAME, start_realm, NULL); if (ret) { free(start_realm); return ret; } ret = find_cred(context, ccache, tgtname, NULL, &tgt); krb5_free_principal(context, tgtname); if (ret) { free(start_realm); return ret; } } referral = *in_creds; ret = krb5_copy_principal(context, in_creds->server, &referral.server); if (ret) { krb5_free_cred_contents(context, &tgt); free(start_realm); return ret; } ret = krb5_principal_set_realm(context, referral.server, start_realm); free(start_realm); start_realm = NULL; 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 contrained deleg */ if (impersonate_principal == NULL || flags.b.cname_in_addl_tkt) { krb5_cc_clear_mcred(&mcreds); mcreds.server = referral.server; krb5_timeofday(context, &mcreds.times.endtime); ret = krb5_cc_retrieve_cred(context, ccache, KRB5_TC_MATCH_TIMES, &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 = referral_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; } _krb5_debug(context, 6, "get_cred_kdc_referral: got referral " "to %s from %s", referral_realm, referral.server->realm); ret = add_cred(context, &ticket, &referral_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: for (i = 0; referral_tgts && referral_tgts[i]; i++) krb5_free_creds(context, referral_tgts[i]); free(referral_tgts); 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_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL _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 == 0) { context->kdc_sec_offset = offset; context->kdc_usec_offset = 0; } if (strcmp(in_creds->server->realm, "") != 0) { /* * Non-empty realm? Try capaths first. We might have local * policy (capaths) to honor. */ ret = get_cred_kdc_capath(context, flags, ccache, in_creds, impersonate_principal, second_ticket, out_creds, ret_tgts); if (ret == 0) return ret; } /* Otherwise try referrals */ return get_cred_kdc_referral(context, flags, ccache, in_creds, impersonate_principal, second_ticket, out_creds); } static krb5_error_code check_cc(krb5_context context, krb5_flags options, krb5_ccache ccache, krb5_creds *in_creds, krb5_creds *out_creds) { krb5_error_code ret; krb5_timestamp now; krb5_creds mcreds = *in_creds; krb5_timeofday(context, &now); if (!(options & KRB5_GC_EXPIRED_OK) && mcreds.times.endtime < now) { mcreds.times.renew_till = 0; krb5_timeofday(context, &mcreds.times.endtime); options |= KRB5_TC_MATCH_TIMES; } if (mcreds.server->name.name_type == KRB5_NT_SRV_HST_NEEDS_CANON) { /* Avoid name canonicalization in krb5_cc_retrieve_cred() */ krb5_principal_set_type(context, mcreds.server, KRB5_NT_SRV_HST); } if (options & KRB5_GC_ANONYMOUS) { ret = krb5_make_principal(context, &mcreds.client, krb5_principal_get_realm(context, mcreds.client), KRB5_WELLKNOWN_NAME, KRB5_ANON_NAME, NULL); if (ret) return ret; } ret = krb5_cc_retrieve_cred(context, ccache, (options & (KRB5_TC_DONT_MATCH_REALM | KRB5_TC_MATCH_KEYTYPE | KRB5_TC_MATCH_TIMES)), &mcreds, out_creds); if (options & KRB5_GC_ANONYMOUS) krb5_free_principal(context, mcreds.client); return ret; } static void store_cred(krb5_context context, krb5_ccache ccache, krb5_const_principal server_princ, krb5_creds *creds) { if (!krb5_principal_compare(context, creds->server, server_princ)) { krb5_principal tmp_princ = creds->server; /* * Store the cred with the pre-canon server princ first so it * can be found quickly in the future. */ creds->server = (krb5_principal)server_princ; krb5_cc_store_cred(context, ccache, creds); creds->server = tmp_princ; /* Then store again with the canonicalized server princ */ } krb5_cc_store_cred(context, ccache, creds); } 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_name_canon_iterator name_canon_iter = NULL; krb5_name_canon_rule_options rule_opts; krb5_const_principal try_princ = NULL; krb5_principal save_princ = in_creds->server; krb5_creds **tgts; krb5_creds *res_creds; int i; if (_krb5_have_debug(context, 5)) { char *unparsed; ret = krb5_unparse_name(context, in_creds->server, &unparsed); if (ret) { _krb5_debug(context, 5, "krb5_get_creds: unable to display " "requested service principal"); } else { _krb5_debug(context, 5, "krb5_get_creds: requesting a ticket " "for %s", unparsed); free(unparsed); } } if (in_creds->session.keytype) { ret = krb5_enctype_valid(context, in_creds->session.keytype); if (ret) return ret; options |= KRB5_TC_MATCH_KEYTYPE; } *out_creds = NULL; res_creds = calloc(1, sizeof(*res_creds)); if (res_creds == NULL) return krb5_enomem(context); ret = krb5_name_canon_iterator_start(context, in_creds->server, &name_canon_iter); if (ret) return ret; next_rule: krb5_free_cred_contents(context, res_creds); memset(res_creds, 0, sizeof (*res_creds)); ret = krb5_name_canon_iterate(context, &name_canon_iter, &try_princ, &rule_opts); in_creds->server = rk_UNCONST(try_princ); if (ret) goto out; if (name_canon_iter == NULL) { if (options & KRB5_GC_CACHED) ret = KRB5_CC_NOTFOUND; else ret = KRB5KDC_ERR_S_PRINCIPAL_UNKNOWN; goto out; } ret = check_cc(context, options, ccache, in_creds, res_creds); if (ret == 0) { *out_creds = res_creds; res_creds = NULL; goto out; } else if(ret != KRB5_CC_END) { goto out; } if (options & KRB5_GC_CACHED) goto next_rule; 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++) { if ((options & KRB5_GC_NO_STORE) == 0) krb5_cc_store_cred(context, ccache, tgts[i]); krb5_free_creds(context, tgts[i]); } free(tgts); /* We don't yet have TGS w/ FAST, so we can't protect KBR-ERRORs */ if (ret == KRB5KDC_ERR_S_PRINCIPAL_UNKNOWN && !(rule_opts & KRB5_NCRO_USE_FAST)) goto next_rule; if(ret == 0 && (options & KRB5_GC_NO_STORE) == 0) store_cred(context, ccache, in_creds->server, *out_creds); if (ret == 0 && _krb5_have_debug(context, 5)) { char *unparsed; ret = krb5_unparse_name(context, (*out_creds)->server, &unparsed); if (ret) { _krb5_debug(context, 5, "krb5_get_creds: unable to display " "service principal"); } else { _krb5_debug(context, 5, "krb5_get_creds: got a ticket for %s", unparsed); free(unparsed); } } out: in_creds->server = save_princ; krb5_free_creds(context, res_creds); krb5_free_name_canon_iterator(context, name_canon_iter); if (ret) return not_found(context, in_creds->server, ret); return 0; } 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) return krb5_enomem(context); 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) return krb5_enomem(context); 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; krb5_const_principal try_princ = NULL; krb5_name_canon_iterator name_canon_iter = NULL; krb5_name_canon_rule_options rule_opts; int i; int type; const char *comp; memset(&in_creds, 0, sizeof(in_creds)); in_creds.server = rk_UNCONST(inprinc); if (_krb5_have_debug(context, 5)) { char *unparsed; ret = krb5_unparse_name(context, in_creds.server, &unparsed); if (ret) { _krb5_debug(context, 5, "krb5_get_creds: unable to display " "requested service principal"); } else { _krb5_debug(context, 5, "krb5_get_creds: requesting a ticket " "for %s", unparsed); free(unparsed); } } if (opt && opt->enctype) { ret = krb5_enctype_valid(context, opt->enctype); if (ret) return ret; } 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); return krb5_enomem(context); } if (opt && opt->enctype) { in_creds.session.keytype = opt->enctype; options |= KRB5_TC_MATCH_KEYTYPE; } ret = krb5_name_canon_iterator_start(context, in_creds.server, &name_canon_iter); if (ret) goto out; next_rule: ret = krb5_name_canon_iterate(context, &name_canon_iter, &try_princ, &rule_opts); in_creds.server = rk_UNCONST(try_princ); if (ret) goto out; if (name_canon_iter == NULL) { if (options & KRB5_GC_CACHED) ret = KRB5_CC_NOTFOUND; else ret = KRB5KDC_ERR_S_PRINCIPAL_UNKNOWN; goto out; } ret = check_cc(context, options, ccache, &in_creds, res_creds); if (ret == 0) { *out_creds = res_creds; res_creds = NULL; goto out; } else if (ret != KRB5_CC_END) { goto out; } if (options & KRB5_GC_CACHED) goto next_rule; type = krb5_principal_get_type(context, try_princ); comp = krb5_principal_get_comp_string(context, try_princ, 0); if ((type == KRB5_NT_SRV_HST || type == KRB5_NT_UNKNOWN) && comp != NULL && strcmp(comp, "host") == 0) flags.b.canonicalize = 1; if (rule_opts & KRB5_NCRO_NO_REFERRALS) flags.b.canonicalize = 0; else flags.b.canonicalize = (options & KRB5_GC_CANONICALIZE) ? 1 : 0; 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.cname_in_addl_tkt = 1; if (options & KRB5_GC_ANONYMOUS) flags.b.request_anonymous = 1; tgts = NULL; ret = _krb5_get_cred_kdc_any(context, flags, ccache, &in_creds, opt ? opt->self : 0, opt ? opt->ticket : 0, out_creds, &tgts); for (i = 0; tgts && tgts[i]; i++) { if ((options & KRB5_GC_NO_STORE) == 0) krb5_cc_store_cred(context, ccache, tgts[i]); krb5_free_creds(context, tgts[i]); } free(tgts); /* We don't yet have TGS w/ FAST, so we can't protect KBR-ERRORs */ if (ret == KRB5KDC_ERR_S_PRINCIPAL_UNKNOWN && !(rule_opts & KRB5_NCRO_USE_FAST)) goto next_rule; if (ret == 0 && (options & KRB5_GC_NO_STORE) == 0) store_cred(context, ccache, inprinc, *out_creds); if (ret == 0 && _krb5_have_debug(context, 5)) { char *unparsed; ret = krb5_unparse_name(context, (*out_creds)->server, &unparsed); if (ret) { _krb5_debug(context, 5, "krb5_get_creds: unable to display " "service principal"); } else { _krb5_debug(context, 5, "krb5_get_creds: got a ticket for %s", unparsed); free(unparsed); } } out: krb5_free_creds(context, res_creds); krb5_free_principal(context, in_creds.client); krb5_free_name_canon_iterator(context, name_canon_iter); if (ret) return not_found(context, inprinc, 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; }