/* * Copyright (c) 1997 - 2004 Kungliga Tekniska Högskolan * (Royal Institute of Technology, Stockholm, Sweden). * 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 RCSID("$Id: get_cred.c,v 1.91.4.3 2004/01/09 00:47:17 lha Exp $"); /* * 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, krb5_key_usage usage) { u_char *buf; size_t buf_size; size_t len; 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, usage /* 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 *key) { if(authdata->len) { size_t len; unsigned char *buf; krb5_crypto crypto; krb5_error_code ret; ASN1_MALLOC_ENCODE(AuthorizationData, buf, len, authdata, &len, ret); if (ret) return ret; ALLOC(req_body->enc_authorization_data, 1); if (req_body->enc_authorization_data == NULL) { free (buf); krb5_set_error_string(context, "malloc: out of memory"); return ENOMEM; } ret = krb5_crypto_init(context, key, 0, &crypto); if (ret) { free (buf); free (req_body->enc_authorization_data); return ret; } krb5_encrypt_EncryptedData(context, crypto, KRB5_KU_TGS_REQ_AUTH_DAT_SUBKEY, /* KRB5_KU_TGS_REQ_AUTH_DAT_SESSION? */ 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, krb5_keyblock **subkey, TGS_REQ *t, krb5_key_usage usage) { 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_string(context, "malloc: out of memory"); goto fail; } t->req_body.etype.val[0] = in_creds->session.keytype; } else { ret = krb5_init_etype(context, &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_string(context, "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_string(context, "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_string(context, "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_string(context, "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_string(context, "malloc: out of memory"); goto fail; } ALLOC_SEQ(t->padata, 1); if (t->padata->val == NULL) { ret = ENOMEM; krb5_set_error_string(context, "malloc: out of memory"); goto fail; } { krb5_auth_context ac; krb5_keyblock *key = NULL; ret = krb5_auth_con_init(context, &ac); if(ret) goto fail; if (krb5_config_get_bool_default(context, NULL, FALSE, "realms", krbtgt->server->realm, "tgs_require_subkey", NULL)) { ret = krb5_generate_subkey (context, &krbtgt->session, &key); if (ret) { krb5_auth_con_free (context, ac); goto fail; } ret = krb5_auth_con_setlocalsubkey(context, ac, key); if (ret) { if (key) krb5_free_keyblock (context, key); krb5_auth_con_free (context, ac); goto fail; } } ret = set_auth_data (context, &t->req_body, &in_creds->authdata, key); if (ret) { if (key) krb5_free_keyblock (context, key); krb5_auth_con_free (context, ac); goto fail; } ret = make_pa_tgs_req(context, ac, &t->req_body, t->padata->val, krbtgt, usage); if(ret) { if (key) krb5_free_keyblock (context, key); krb5_auth_con_free(context, ac); goto fail; } *subkey = key; krb5_auth_con_free(context, ac); } fail: 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 decrypt_tkt_with_subkey (krb5_context context, krb5_keyblock *key, krb5_key_usage usage, krb5_const_pointer subkey, krb5_kdc_rep *dec_rep) { krb5_error_code ret; krb5_data data; size_t size; krb5_crypto crypto; ret = krb5_crypto_init(context, key, 0, &crypto); if (ret) return ret; ret = krb5_decrypt_EncryptedData (context, crypto, usage, &dec_rep->kdc_rep.enc_part, &data); krb5_crypto_destroy(context, crypto); if(ret && subkey){ /* DCE compat -- try to decrypt with subkey */ ret = krb5_crypto_init(context, (krb5_keyblock*)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); krb5_crypto_destroy(context, crypto); } if (ret) return ret; ret = krb5_decode_EncASRepPart(context, data.data, data.length, &dec_rep->enc_part, &size); if (ret) ret = krb5_decode_EncTGSRepPart(context, data.data, data.length, &dec_rep->enc_part, &size); krb5_data_free (&data); return ret; } static krb5_error_code get_cred_kdc_usage(krb5_context context, krb5_ccache id, krb5_kdc_flags flags, krb5_addresses *addresses, krb5_creds *in_creds, krb5_creds *krbtgt, krb5_creds *out_creds, krb5_key_usage usage) { 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; u_char *buf = NULL; size_t buf_size; size_t len; Ticket second_ticket; krb5_generate_random_block(&nonce, sizeof(nonce)); nonce &= 0xffffffff; if(flags.b.enc_tkt_in_skey){ ret = decode_Ticket(in_creds->second_ticket.data, in_creds->second_ticket.length, &second_ticket, &len); if(ret) return ret; } ret = init_tgs_req (context, id, addresses, flags, flags.b.enc_tkt_in_skey ? &second_ticket : NULL, in_creds, krbtgt, nonce, &subkey, &req, usage); if(flags.b.enc_tkt_in_skey) free_Ticket(&second_ticket); if (ret) goto out; ASN1_MALLOC_ENCODE(TGS_REQ, buf, buf_size, &req, &enc.length, ret); if (ret) goto out; if(enc.length != buf_size) krb5_abortx(context, "internal error in ASN.1 encoder"); /* don't free addresses */ req.req_body.addresses = NULL; free_TGS_REQ(&req); enc.data = buf + buf_size - enc.length; if (ret) goto out; /* * Send and receive */ ret = krb5_sendto_kdc (context, &enc, &krbtgt->server->name.name_string.val[1], &resp); if(ret) goto out; memset(&rep, 0, sizeof(rep)); if(decode_TGS_REP(resp.data, resp.length, &rep.kdc_rep, &len) == 0){ ret = krb5_copy_principal(context, in_creds->client, &out_creds->client); if(ret) goto out; ret = krb5_copy_principal(context, in_creds->server, &out_creds->server); if(ret) goto out; /* this should go someplace else */ out_creds->times.endtime = in_creds->times.endtime; ret = _krb5_extract_ticket(context, &rep, out_creds, &krbtgt->session, NULL, KRB5_KU_TGS_REP_ENC_PART_SESSION, &krbtgt->addresses, nonce, TRUE, flags.b.request_anonymous, decrypt_tkt_with_subkey, subkey); krb5_free_kdc_rep(context, &rep); if (ret) goto out; } 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.data && ((char*)resp.data)[0] == 4) { ret = KRB5KRB_AP_ERR_V4_REPLY; krb5_clear_error_string(context); } else { ret = KRB5KRB_AP_ERR_MSG_TYPE; krb5_clear_error_string(context); } krb5_data_free(&resp); out: if(subkey){ krb5_free_keyblock_contents(context, subkey); free(subkey); } if (buf) free (buf); 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_creds *out_creds) { krb5_error_code ret; ret = get_cred_kdc_usage(context, id, flags, addresses, in_creds, krbtgt, out_creds, KRB5_KU_TGS_REQ_AUTH); if (ret == KRB5KRB_AP_ERR_BAD_INTEGRITY) { krb5_clear_error_string (context); ret = get_cred_kdc_usage(context, id, flags, addresses, in_creds, krbtgt, out_creds, KRB5_KU_AP_REQ_AUTH); } return ret; } /* same as above, just get local addresses first */ static krb5_error_code get_cred_kdc_la(krb5_context context, krb5_ccache id, krb5_kdc_flags flags, krb5_creds *in_creds, krb5_creds *krbtgt, krb5_creds *out_creds) { krb5_error_code ret; krb5_addresses addresses, *addrs = &addresses; krb5_get_all_client_addrs(context, &addresses); /* XXX this sucks. */ if(addresses.len == 0) addrs = NULL; ret = get_cred_kdc(context, id, flags, addrs, in_creds, krbtgt, out_creds); krb5_free_addresses(context, &addresses); return ret; } krb5_error_code 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_string(context, "malloc: out of memory"); return ENOMEM; } ret = _krb5_get_krbtgt (context, id, in_creds->server->realm, &krbtgt); if(ret) { free(*out_creds); return ret; } ret = get_cred_kdc(context, id, flags, addresses, in_creds, krbtgt, *out_creds); krb5_free_creds (context, krbtgt); if(ret) free(*out_creds); return ret; } 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; 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++; } krb5_clear_error_string(context); return KRB5_CC_NOTFOUND; } static krb5_error_code add_cred(krb5_context context, krb5_creds ***tgts, krb5_creds *tkt) { 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_string(context, "malloc: out of memory"); return ENOMEM; } *tgts = tmp; ret = krb5_copy_creds(context, tkt, &tmp[i]); tmp[i+1] = NULL; 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_from_kdc_flags(krb5_context context, krb5_kdc_flags flags, krb5_ccache ccache, krb5_creds *in_creds, krb5_creds **out_creds, krb5_creds ***ret_tgts) { krb5_error_code ret; krb5_creds *tgt, tmp_creds; krb5_const_realm client_realm, server_realm, try_realm; *out_creds = NULL; client_realm = *krb5_princ_realm(context, in_creds->client); server_realm = *krb5_princ_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; try_realm = krb5_config_get_string(context, NULL, "capaths", client_realm, server_realm, NULL); #if 1 /* XXX remove in future release */ if(try_realm == NULL) try_realm = krb5_config_get_string(context, NULL, "libdefaults", "capath", server_realm, NULL); #endif if (try_realm == NULL) try_realm = client_realm; 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; /* XXX try krb5_cc_retrieve_cred first? */ ret = find_cred(context, ccache, tmp_creds.server, *ret_tgts, &tgts); if(ret == 0){ *out_creds = calloc(1, sizeof(**out_creds)); if(*out_creds == NULL) { krb5_set_error_string(context, "malloc: out of memory"); ret = ENOMEM; } else { krb5_boolean noaddr; krb5_appdefault_boolean(context, NULL, tgts.server->realm, "no-addresses", FALSE, &noaddr); if (noaddr) ret = get_cred_kdc(context, ccache, flags, NULL, in_creds, &tgts, *out_creds); else ret = get_cred_kdc_la(context, ccache, flags, in_creds, &tgts, *out_creds); if (ret) { free (*out_creds); *out_creds = NULL; } } krb5_free_creds_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)) { krb5_clear_error_string (context); return KRB5_CC_NOTFOUND; } /* XXX this can loop forever */ while(1){ general_string tgt_inst; ret = get_cred_from_kdc_flags(context, flags, ccache, &tmp_creds, &tgt, ret_tgts); if(ret) { krb5_free_principal(context, tmp_creds.server); krb5_free_principal(context, tmp_creds.client); return ret; } ret = add_cred(context, ret_tgts, tgt); 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); 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) { krb5_set_error_string(context, "malloc: out of memory"); ret = ENOMEM; } else { krb5_boolean noaddr; krb5_appdefault_boolean(context, NULL, tgt->server->realm, "no-addresses", FALSE, &noaddr); if (noaddr) ret = get_cred_kdc (context, ccache, flags, NULL, in_creds, tgt, *out_creds); else ret = get_cred_kdc_la(context, ccache, flags, in_creds, tgt, *out_creds); if (ret) { free (*out_creds); *out_creds = NULL; } } krb5_free_creds(context, tgt); return ret; } krb5_error_code krb5_get_cred_from_kdc_opt(krb5_context context, krb5_ccache ccache, krb5_creds *in_creds, krb5_creds **out_creds, krb5_creds ***ret_tgts, krb5_flags flags) { krb5_kdc_flags f; f.i = flags; return get_cred_from_kdc_flags(context, f, ccache, in_creds, out_creds, ret_tgts); } krb5_error_code krb5_get_cred_from_kdc(krb5_context context, krb5_ccache ccache, krb5_creds *in_creds, krb5_creds **out_creds, krb5_creds ***ret_tgts) { return krb5_get_cred_from_kdc_opt(context, ccache, in_creds, out_creds, ret_tgts, 0); } krb5_error_code 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; *out_creds = NULL; res_creds = calloc(1, sizeof(*res_creds)); if (res_creds == NULL) { krb5_set_error_string(context, "malloc: out of memory"); return ENOMEM; } ret = krb5_cc_retrieve_cred(context, ccache, in_creds->session.keytype ? KRB5_TC_MATCH_KEYTYPE : 0, in_creds, res_creds); if(ret == 0) { *out_creds = res_creds; return 0; } free(res_creds); if(ret != KRB5_CC_END) return ret; if(options & KRB5_GC_CACHED) { krb5_clear_error_string (context); return KRB5_CC_NOTFOUND; } if(options & KRB5_GC_USER_USER) flags.b.enc_tkt_in_skey = 1; tgts = NULL; ret = get_cred_from_kdc_flags(context, flags, ccache, in_creds, 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 && flags.b.enc_tkt_in_skey == 0) krb5_cc_store_cred(context, ccache, *out_creds); return ret; } krb5_error_code 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); }