diff options
Diffstat (limited to 'third_party/heimdal/lib/krb5/rd_req.c')
| -rw-r--r-- | third_party/heimdal/lib/krb5/rd_req.c | 1107 |
1 files changed, 1107 insertions, 0 deletions
diff --git a/third_party/heimdal/lib/krb5/rd_req.c b/third_party/heimdal/lib/krb5/rd_req.c new file mode 100644 index 0000000..012cfef --- /dev/null +++ b/third_party/heimdal/lib/krb5/rd_req.c @@ -0,0 +1,1107 @@ + +/* + * Copyright (c) 1997 - 2007 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 "krb5_locl.h" + +static krb5_error_code +decrypt_tkt_enc_part (krb5_context context, + krb5_keyblock *key, + EncryptedData *enc_part, + EncTicketPart *decr_part) +{ + krb5_error_code ret; + krb5_data plain; + size_t len; + krb5_crypto crypto; + + ret = krb5_crypto_init(context, key, 0, &crypto); + if (ret) + return ret; + ret = krb5_decrypt_EncryptedData (context, + crypto, + KRB5_KU_TICKET, + enc_part, + &plain); + krb5_crypto_destroy(context, crypto); + if (ret) + return ret; + + ret = decode_EncTicketPart(plain.data, plain.length, decr_part, &len); + if (ret) + krb5_set_error_message(context, ret, + N_("Failed to decode encrypted " + "ticket part", "")); + krb5_data_free (&plain); + return ret; +} + +static krb5_error_code +decrypt_authenticator (krb5_context context, + EncryptionKey *key, + EncryptedData *enc_part, + Authenticator *authenticator, + krb5_key_usage usage) +{ + krb5_error_code ret; + krb5_data plain; + size_t len; + krb5_crypto crypto; + + ret = krb5_crypto_init(context, key, 0, &crypto); + if (ret) + return ret; + ret = krb5_decrypt_EncryptedData (context, + crypto, + usage /* KRB5_KU_AP_REQ_AUTH */, + enc_part, + &plain); + /* for backwards compatibility, also try the old usage */ + if (ret && usage == KRB5_KU_TGS_REQ_AUTH) + ret = krb5_decrypt_EncryptedData (context, + crypto, + KRB5_KU_AP_REQ_AUTH, + enc_part, + &plain); + krb5_crypto_destroy(context, crypto); + if (ret) + return ret; + + ret = decode_Authenticator(plain.data, plain.length, + authenticator, &len); + krb5_data_free (&plain); + return ret; +} + +KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL +krb5_decode_ap_req(krb5_context context, + const krb5_data *inbuf, + krb5_ap_req *ap_req) +{ + krb5_error_code ret; + size_t len; + ret = decode_AP_REQ(inbuf->data, inbuf->length, ap_req, &len); + if (ret) + return ret; + if (ap_req->pvno != 5){ + free_AP_REQ(ap_req); + krb5_clear_error_message (context); + return KRB5KRB_AP_ERR_BADVERSION; + } + if (ap_req->msg_type != krb_ap_req){ + free_AP_REQ(ap_req); + krb5_clear_error_message (context); + return KRB5KRB_AP_ERR_MSG_TYPE; + } + if (ap_req->ticket.tkt_vno != 5){ + free_AP_REQ(ap_req); + krb5_clear_error_message (context); + return KRB5KRB_AP_ERR_BADVERSION; + } + return 0; +} + +static krb5_error_code +check_transited(krb5_context context, Ticket *ticket, EncTicketPart *enc) +{ + char **realms; + unsigned int num_realms, n; + krb5_error_code ret; + + /* + * Windows 2000 and 2003 uses this inside their TGT so it's normaly + * not seen by others, however, samba4 joined with a Windows AD as + * a Domain Controller gets exposed to this. + */ + if(enc->transited.tr_type == 0 && enc->transited.contents.length == 0) + return 0; + + if(enc->transited.tr_type != domain_X500_Compress) + return KRB5KDC_ERR_TRTYPE_NOSUPP; + + if(enc->transited.contents.length == 0) + return 0; + + ret = krb5_domain_x500_decode(context, enc->transited.contents, + &realms, &num_realms, + enc->crealm, + ticket->realm); + if(ret) + return ret; + ret = krb5_check_transited(context, enc->crealm, + ticket->realm, + realms, num_realms, NULL); + for (n = 0; n < num_realms; n++) + free(realms[n]); + free(realms); + return ret; +} + +static krb5_error_code +find_etypelist(krb5_context context, + krb5_auth_context auth_context, + EtypeList *etypes) +{ + krb5_error_code ret; + krb5_data data; + + ret = _krb5_get_ad(context, auth_context->authenticator->authorization_data, NULL, KRB5_AUTHDATA_GSS_API_ETYPE_NEGOTIATION, &data); + if (ret) + return 0; + + ret = decode_EtypeList(data.data, data.length, etypes, NULL); + krb5_data_free(&data); + if (ret) + krb5_clear_error_message(context); + + return ret; +} + +KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL +krb5_decrypt_ticket(krb5_context context, + Ticket *ticket, + krb5_keyblock *key, + EncTicketPart *out, + krb5_flags flags) +{ + EncTicketPart t; + krb5_error_code ret; + ret = decrypt_tkt_enc_part (context, key, &ticket->enc_part, &t); + if (ret) + return ret; + + { + krb5_timestamp now; + time_t start = t.authtime; + + krb5_timeofday (context, &now); + if(t.starttime) + start = *t.starttime; + if(start - now > context->max_skew + || (t.flags.invalid + && !(flags & KRB5_VERIFY_AP_REQ_IGNORE_INVALID))) { + free_EncTicketPart(&t); + krb5_clear_error_message (context); + return KRB5KRB_AP_ERR_TKT_NYV; + } + if(now - t.endtime > context->max_skew) { + free_EncTicketPart(&t); + krb5_clear_error_message (context); + return KRB5KRB_AP_ERR_TKT_EXPIRED; + } + + if(!t.flags.transited_policy_checked) { + ret = check_transited(context, ticket, &t); + if(ret) { + free_EncTicketPart(&t); + return ret; + } + } + } + + if(out) + *out = t; + else + free_EncTicketPart(&t); + return 0; +} + +KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL +krb5_verify_authenticator_checksum(krb5_context context, + krb5_auth_context ac, + void *data, + size_t len) +{ + krb5_error_code ret; + krb5_keyblock *key = NULL; + krb5_authenticator authenticator; + krb5_crypto crypto; + + ret = krb5_auth_con_getauthenticator(context, ac, &authenticator); + if (ret) + return ret; + if (authenticator->cksum == NULL) { + ret = -17; + goto out; + } + ret = krb5_auth_con_getkey(context, ac, &key); + if (ret) + goto out; + ret = krb5_crypto_init(context, key, 0, &crypto); + if (ret) + goto out; + + _krb5_crypto_set_flags(context, crypto, KRB5_CRYPTO_FLAG_ALLOW_UNKEYED_CHECKSUM); + ret = krb5_verify_checksum(context, crypto, + KRB5_KU_AP_REQ_AUTH_CKSUM, + data, len, authenticator->cksum); + krb5_crypto_destroy(context, crypto); +out: + krb5_free_authenticator(context, &authenticator); + krb5_free_keyblock(context, key); + return ret; +} + + +KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL +krb5_verify_ap_req(krb5_context context, + krb5_auth_context *auth_context, + krb5_ap_req *ap_req, + krb5_const_principal server, + krb5_keyblock *keyblock, + krb5_flags flags, + krb5_flags *ap_req_options, + krb5_ticket **ticket) +{ + return krb5_verify_ap_req2 (context, + auth_context, + ap_req, + server, + keyblock, + flags, + ap_req_options, + ticket, + KRB5_KU_AP_REQ_AUTH); +} + +KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL +krb5_verify_ap_req2(krb5_context context, + krb5_auth_context *auth_context, + krb5_ap_req *ap_req, + krb5_const_principal server, + krb5_keyblock *keyblock, + krb5_flags flags, + krb5_flags *ap_req_options, + krb5_ticket **ticket, + krb5_key_usage usage) +{ + krb5_ticket *t; + krb5_auth_context ac; + krb5_error_code ret; + EtypeList etypes; + int badaddr = 0; + + memset(&etypes, 0, sizeof(etypes)); + + if (ticket) + *ticket = NULL; + + if (auth_context && *auth_context) { + ac = *auth_context; + } else { + ret = krb5_auth_con_init (context, &ac); + if (ret) + return ret; + } + + t = calloc(1, sizeof(*t)); + if (t == NULL) { + ret = krb5_enomem(context); + goto out; + } + + if (ap_req->ap_options.use_session_key && ac->keyblock){ + ret = krb5_decrypt_ticket(context, &ap_req->ticket, + ac->keyblock, + &t->ticket, + flags); + krb5_free_keyblock(context, ac->keyblock); + ac->keyblock = NULL; + }else + ret = krb5_decrypt_ticket(context, &ap_req->ticket, + keyblock, + &t->ticket, + flags); + + if(ret) + goto out; + + ret = _krb5_principalname2krb5_principal(context, + &t->server, + ap_req->ticket.sname, + ap_req->ticket.realm); + if (ret) goto out; + + ret = decrypt_authenticator (context, + &t->ticket.key, + &ap_req->authenticator, + ac->authenticator, + usage); + if (ret) + goto out; + + { + krb5_principal p1, p2; + krb5_boolean res; + + _krb5_principalname2krb5_principal(context, + &p1, + ac->authenticator->cname, + ac->authenticator->crealm); + _krb5_principalname2krb5_principal(context, + &p2, + t->ticket.cname, + t->ticket.crealm); + res = krb5_principal_compare (context, p1, p2); + krb5_free_principal (context, p1); + krb5_free_principal (context, p2); + if (!res) { + ret = KRB5KRB_AP_ERR_BADMATCH; + krb5_clear_error_message (context); + goto out; + } + } + + /* + * The ticket authenticates the client, and conveys naming attributes that + * we want to expose in GSS using RFC6680 APIs. + * + * So we same the ticket enc-part in the client's krb5_principal object + * (note though that the session key will be absent in that copy of the + * ticket enc-part). + */ + ret = _krb5_ticket2krb5_principal(context, &t->client, &t->ticket, + ac->authenticator->authorization_data); + if (ret) goto out; + + t->client->nameattrs->peer_realm = + calloc(1, sizeof(t->client->nameattrs->peer_realm[0])); + if (t->client->nameattrs->peer_realm == NULL) { + ret = krb5_enomem(context); + goto out; + } + ret = copy_Realm(&ap_req->ticket.realm, t->client->nameattrs->peer_realm); + if (ret) goto out; + + /* check addresses */ + + if (t->ticket.caddr + && ac->remote_address + && !krb5_address_search (context, + ac->remote_address, + t->ticket.caddr)) { + /* + * Hack alert. If KRB5_VERIFY_AP_REQ_IGNORE_ADDRS and the client's + * address didn't check out then we'll return KRB5KRB_AP_ERR_BADADDR + * even on success, and we'll let the caller figure it out because + * `*ticket != NULL' or `*auth_context != NULL'. + */ + if ((flags & KRB5_VERIFY_AP_REQ_IGNORE_ADDRS)) { + badaddr = 1; + } else { + ret = KRB5KRB_AP_ERR_BADADDR; + krb5_clear_error_message(context); + goto out; + } + } + + /* check timestamp in authenticator */ + { + krb5_timestamp now; + + krb5_timeofday (context, &now); + + if (krb5_time_abs(ac->authenticator->ctime, now) > context->max_skew) { + ret = KRB5KRB_AP_ERR_SKEW; + krb5_clear_error_message (context); + goto out; + } + } + + if (ac->authenticator->seq_number) + krb5_auth_con_setremoteseqnumber(context, ac, + *ac->authenticator->seq_number); + + /* XXX - Xor sequence numbers */ + + if (ac->authenticator->subkey) { + ret = krb5_auth_con_setremotesubkey(context, ac, + ac->authenticator->subkey); + if (ret) + goto out; + } + + ret = find_etypelist(context, ac, &etypes); + if (ret) + goto out; + + ac->keytype = ETYPE_NULL; + + if (etypes.val) { + size_t i; + + for (i = 0; i < etypes.len; i++) { + if (krb5_enctype_valid(context, etypes.val[i]) == 0) { + ac->keytype = etypes.val[i]; + break; + } + } + } + + /* save key */ + ret = krb5_copy_keyblock(context, &t->ticket.key, &ac->keyblock); + if (ret) goto out; + + if (ap_req_options) { + *ap_req_options = 0; + if (ac->keytype != ETYPE_NULL) + *ap_req_options |= AP_OPTS_USE_SUBKEY; + if (ap_req->ap_options.use_session_key) + *ap_req_options |= AP_OPTS_USE_SESSION_KEY; + if (ap_req->ap_options.mutual_required) + *ap_req_options |= AP_OPTS_MUTUAL_REQUIRED; + } + + if(ticket) + *ticket = t; + else + krb5_free_ticket (context, t); + if (auth_context) { + if (*auth_context == NULL) + *auth_context = ac; + } else + krb5_auth_con_free (context, ac); + free_EtypeList(&etypes); + + if (badaddr) { + krb5_clear_error_message(context); + return KRB5KRB_AP_ERR_BADADDR; + } + return 0; + out: + free_EtypeList(&etypes); + if (t) + krb5_free_ticket (context, t); + if (auth_context == NULL || *auth_context == NULL) + krb5_auth_con_free (context, ac); + return ret; +} + +/* + * + */ + +struct krb5_rd_req_in_ctx_data { + krb5_keytab keytab; + krb5_keyblock *keyblock; + krb5_boolean check_pac; +}; + +struct krb5_rd_req_out_ctx_data { + krb5_keyblock *keyblock; + krb5_flags ap_req_options; + krb5_ticket *ticket; + krb5_principal server; +}; + +/** + * Allocate a krb5_rd_req_in_ctx as an input parameter to + * krb5_rd_req_ctx(). The caller should free the context with + * krb5_rd_req_in_ctx_free() when done with the context. + * + * @param context Keberos 5 context. + * @param ctx in ctx to krb5_rd_req_ctx(). + * + * @return Kerberos 5 error code, see krb5_get_error_message(). + * + * @ingroup krb5_auth + */ + +KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL +krb5_rd_req_in_ctx_alloc(krb5_context context, krb5_rd_req_in_ctx *ctx) +{ + *ctx = calloc(1, sizeof(**ctx)); + if (*ctx == NULL) + return krb5_enomem(context); + (*ctx)->check_pac = (context->flags & KRB5_CTX_F_CHECK_PAC) ? 1 : 0; + return 0; +} + +/** + * Set the keytab that krb5_rd_req_ctx() will use. + * + * @param context Keberos 5 context. + * @param in in ctx to krb5_rd_req_ctx(). + * @param keytab keytab that krb5_rd_req_ctx() will use, only copy the + * pointer, so the caller must free they keytab after + * krb5_rd_req_in_ctx_free() is called. + * + * @return Kerberos 5 error code, see krb5_get_error_message(). + * + * @ingroup krb5_auth + */ + +KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL +krb5_rd_req_in_set_keytab(krb5_context context, + krb5_rd_req_in_ctx in, + krb5_keytab keytab) +{ + in->keytab = keytab; + return 0; +} + +/** + * Set if krb5_rq_red() is going to check the Windows PAC or not + * + * @param context Keberos 5 context. + * @param in krb5_rd_req_in_ctx to check the option on. + * @param flag flag to select if to check the pac (TRUE) or not (FALSE). + * + * @return Kerberos 5 error code, see krb5_get_error_message(). + * + * @ingroup krb5_auth + */ + +KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL +krb5_rd_req_in_set_pac_check(krb5_context context, + krb5_rd_req_in_ctx in, + krb5_boolean flag) +{ + in->check_pac = flag; + return 0; +} + + +KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL +krb5_rd_req_in_set_keyblock(krb5_context context, + krb5_rd_req_in_ctx in, + krb5_keyblock *keyblock) +{ + in->keyblock = keyblock; /* XXX should make copy */ + return 0; +} + +KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL +krb5_rd_req_out_get_ap_req_options(krb5_context context, + krb5_rd_req_out_ctx out, + krb5_flags *ap_req_options) +{ + *ap_req_options = out->ap_req_options; + return 0; +} + +KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL +krb5_rd_req_out_get_ticket(krb5_context context, + krb5_rd_req_out_ctx out, + krb5_ticket **ticket) +{ + return krb5_copy_ticket(context, out->ticket, ticket); +} + +KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL +krb5_rd_req_out_get_keyblock(krb5_context context, + krb5_rd_req_out_ctx out, + krb5_keyblock **keyblock) +{ + return krb5_copy_keyblock(context, out->keyblock, keyblock); +} + +/** + * Get the principal that was used in the request from the + * client. Might not match whats in the ticket if krb5_rd_req_ctx() + * searched in the keytab for a matching key. + * + * @param context a Kerberos 5 context. + * @param out a krb5_rd_req_out_ctx from krb5_rd_req_ctx(). + * @param principal return principal, free with krb5_free_principal(). + * + * @ingroup krb5_auth + */ + +KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL +krb5_rd_req_out_get_server(krb5_context context, + krb5_rd_req_out_ctx out, + krb5_principal *principal) +{ + return krb5_copy_principal(context, out->server, principal); +} + +KRB5_LIB_FUNCTION void KRB5_LIB_CALL +krb5_rd_req_in_ctx_free(krb5_context context, krb5_rd_req_in_ctx ctx) +{ + free(ctx); +} + +/** + * Free the krb5_rd_req_out_ctx. + * + * @param context Keberos 5 context. + * @param ctx krb5_rd_req_out_ctx context to free. + * + * @ingroup krb5_auth + */ + +KRB5_LIB_FUNCTION void KRB5_LIB_CALL +krb5_rd_req_out_ctx_free(krb5_context context, krb5_rd_req_out_ctx ctx) +{ + if (ctx->ticket) + krb5_free_ticket(context, ctx->ticket); + if (ctx->keyblock) + krb5_free_keyblock(context, ctx->keyblock); + if (ctx->server) + krb5_free_principal(context, ctx->server); + free(ctx); +} + +/** + * Process an AP_REQ message. + * + * @param context Kerberos 5 context. + * @param auth_context authentication context of the peer. + * @param inbuf the AP_REQ message, obtained for example with krb5_read_message(). + * @param server server principal. + * @param keytab server keytab. + * @param ap_req_options set to the AP_REQ options. See the AP_OPTS_* defines. + * @param ticket on success, set to the authenticated client credentials. + * Must be deallocated with krb5_free_ticket(). If not + * interested, pass a NULL value. + * + * @return 0 to indicate success. Otherwise a Kerberos error code is + * returned, see krb5_get_error_message(). + */ +KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL +krb5_rd_req(krb5_context context, + krb5_auth_context *auth_context, + const krb5_data *inbuf, + krb5_const_principal server, + krb5_keytab keytab, + krb5_flags *ap_req_options, + krb5_ticket **ticket) +{ + krb5_error_code ret; + krb5_rd_req_in_ctx in; + krb5_rd_req_out_ctx out; + + ret = krb5_rd_req_in_ctx_alloc(context, &in); + if (ret) + return ret; + + ret = krb5_rd_req_in_set_keytab(context, in, keytab); + if (ret) { + krb5_rd_req_in_ctx_free(context, in); + return ret; + } + + ret = krb5_rd_req_ctx(context, auth_context, inbuf, server, in, &out); + krb5_rd_req_in_ctx_free(context, in); + if (ret) + return ret; + + if (ap_req_options) + *ap_req_options = out->ap_req_options; + if (ticket) { + ret = krb5_copy_ticket(context, out->ticket, ticket); + if (ret) + goto out; + } + +out: + krb5_rd_req_out_ctx_free(context, out); + return ret; +} + +/* + * + */ + +KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL +krb5_rd_req_with_keyblock(krb5_context context, + krb5_auth_context *auth_context, + const krb5_data *inbuf, + krb5_const_principal server, + krb5_keyblock *keyblock, + krb5_flags *ap_req_options, + krb5_ticket **ticket) +{ + krb5_error_code ret; + krb5_rd_req_in_ctx in; + krb5_rd_req_out_ctx out; + + ret = krb5_rd_req_in_ctx_alloc(context, &in); + if (ret) + return ret; + + ret = krb5_rd_req_in_set_keyblock(context, in, keyblock); + if (ret) { + krb5_rd_req_in_ctx_free(context, in); + return ret; + } + + ret = krb5_rd_req_ctx(context, auth_context, inbuf, server, in, &out); + krb5_rd_req_in_ctx_free(context, in); + if (ret) + return ret; + + if (ap_req_options) + *ap_req_options = out->ap_req_options; + if (ticket) { + ret = krb5_copy_ticket(context, out->ticket, ticket); + if (ret) + goto out; + } + +out: + krb5_rd_req_out_ctx_free(context, out); + return ret; +} + +/* + * + */ + +static krb5_error_code +get_key_from_keytab(krb5_context context, + krb5_ap_req *ap_req, + krb5_const_principal server, + krb5_keytab keytab, + krb5_keyblock **out_key) +{ + krb5_keytab_entry entry; + krb5_error_code ret; + int kvno; + krb5_keytab real_keytab; + + if(keytab == NULL) + krb5_kt_default(context, &real_keytab); + else + real_keytab = keytab; + + if (ap_req->ticket.enc_part.kvno) + kvno = *ap_req->ticket.enc_part.kvno; + else + kvno = 0; + + ret = krb5_kt_get_entry (context, + real_keytab, + server, + kvno, + ap_req->ticket.enc_part.etype, + &entry); + if(ret == 0) { + ret = krb5_copy_keyblock(context, &entry.keyblock, out_key); + krb5_kt_free_entry(context, &entry); + } + if(keytab == NULL) + krb5_kt_close(context, real_keytab); + + return ret; +} + +/** + * The core server function that verify application authentication + * requests from clients. + * + * @param context Keberos 5 context. + * @param auth_context the authentication context, can be NULL, then + * default values for the authentication context will used. + * @param inbuf the (AP-REQ) authentication buffer + * + * @param server the server to authenticate to. If NULL the function + * will try to find any available credential in the keytab + * that will verify the reply. The function will prefer the + * server specified in the AP-REQ, but if + * there is no mach, it will try all keytab entries for a + * match. This has serious performance issues for large keytabs. + * + * @param inctx control the behavior of the function, if NULL, the + * default behavior is used. + * @param outctx the return outctx, free with krb5_rd_req_out_ctx_free(). + * @return Kerberos 5 error code, see krb5_get_error_message(). + * + * @ingroup krb5_auth + */ + +KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL +krb5_rd_req_ctx(krb5_context context, + krb5_auth_context *auth_context, + const krb5_data *inbuf, + krb5_const_principal server, + krb5_rd_req_in_ctx inctx, + krb5_rd_req_out_ctx *outctx) +{ + krb5_error_code ret; + krb5_ap_req ap_req; + krb5_rd_req_out_ctx o = NULL; + krb5_keytab id = NULL, keytab = NULL; + krb5_principal service = NULL; + + if (outctx) + *outctx = NULL; + + o = calloc(1, sizeof(*o)); + if (o == NULL) + return krb5_enomem(context); + + if (*auth_context == NULL) { + ret = krb5_auth_con_init(context, auth_context); + if (ret) + goto out; + } + + ret = krb5_decode_ap_req(context, inbuf, &ap_req); + if(ret) + goto out; + + /* Save the principal that was in the request */ + ret = _krb5_principalname2krb5_principal(context, + &o->server, + ap_req.ticket.sname, + ap_req.ticket.realm); + if (ret) + goto out; + + if (ap_req.ap_options.use_session_key && + (*auth_context)->keyblock == NULL) { + ret = KRB5KRB_AP_ERR_NOKEY; + krb5_set_error_message(context, ret, + N_("krb5_rd_req: user to user auth " + "without session key given", "")); + goto out; + } + + if (inctx && inctx->keytab) + id = inctx->keytab; + + if((*auth_context)->keyblock){ + ret = krb5_copy_keyblock(context, + (*auth_context)->keyblock, + &o->keyblock); + if (ret) + goto out; + } else if(inctx && inctx->keyblock){ + ret = krb5_copy_keyblock(context, + inctx->keyblock, + &o->keyblock); + if (ret) + goto out; + } else { + + if(id == NULL) { + krb5_kt_default(context, &keytab); + id = keytab; + } + if (id == NULL) + goto out; + + if (server == NULL) { + ret = _krb5_principalname2krb5_principal(context, + &service, + ap_req.ticket.sname, + ap_req.ticket.realm); + if (ret) + goto out; + server = service; + } + + ret = get_key_from_keytab(context, + &ap_req, + server, + id, + &o->keyblock); + if (ret) { + /* If caller specified a server, fail. */ + if (service == NULL && (context->flags & KRB5_CTX_F_RD_REQ_IGNORE) == 0) + goto out; + /* Otherwise, fall back to iterating over the keytab. This + * have serious performace issues for larger keytab. + */ + o->keyblock = NULL; + } + } + + if (o->keyblock) { + /* + * We got an exact keymatch, use that. + */ + + ret = krb5_verify_ap_req2(context, + auth_context, + &ap_req, + server, + o->keyblock, + 0, + &o->ap_req_options, + &o->ticket, + KRB5_KU_AP_REQ_AUTH); + + if (ret) + goto out; + + } else { + /* + * Interate over keytab to find a key that can decrypt the request. + */ + + krb5_keytab_entry entry; + krb5_kt_cursor cursor; + int done = 0, kvno = 0; + + memset(&cursor, 0, sizeof(cursor)); + + if (ap_req.ticket.enc_part.kvno) + kvno = *ap_req.ticket.enc_part.kvno; + + ret = krb5_kt_start_seq_get(context, id, &cursor); + if (ret) + goto out; + + done = 0; + while (!done) { + krb5_principal p; + + ret = krb5_kt_next_entry(context, id, &entry, &cursor); + if (ret) { + _krb5_kt_principal_not_found(context, ret, id, o->server, + ap_req.ticket.enc_part.etype, + kvno); + break; + } + + if (entry.keyblock.keytype != ap_req.ticket.enc_part.etype) { + krb5_kt_free_entry (context, &entry); + continue; + } + + ret = krb5_verify_ap_req2(context, + auth_context, + &ap_req, + server, + &entry.keyblock, + 0, + &o->ap_req_options, + &o->ticket, + KRB5_KU_AP_REQ_AUTH); + if (ret) { + krb5_kt_free_entry (context, &entry); + continue; + } + + /* + * Found a match, save the keyblock for PAC processing, + * and update the service principal in the ticket to match + * whatever is in the keytab. + */ + + ret = krb5_copy_keyblock(context, + &entry.keyblock, + &o->keyblock); + if (ret) { + krb5_kt_free_entry (context, &entry); + break; + } + + ret = krb5_copy_principal(context, entry.principal, &p); + if (ret) { + krb5_kt_free_entry (context, &entry); + break; + } + krb5_free_principal(context, o->ticket->server); + o->ticket->server = p; + + krb5_kt_free_entry (context, &entry); + + done = 1; + } + krb5_kt_end_seq_get (context, id, &cursor); + if (ret) + goto out; + } + + if (krb5_ticket_get_authorization_data_type(context, o->ticket, + KRB5_AUTHDATA_KDC_ISSUED, + NULL) == 0) + o->ticket->client->nameattrs->kdc_issued_verified = 1; + + /* If there is a PAC, verify its server signature */ + if (inctx == NULL || inctx->check_pac) { + krb5_pac pac; + krb5_data data; + + ret = krb5_ticket_get_authorization_data_type(context, + o->ticket, + KRB5_AUTHDATA_WIN2K_PAC, + &data); + if (ret == 0) { + ret = krb5_pac_parse(context, data.data, data.length, &pac); + krb5_data_free(&data); + if (ret) + goto out; + + ret = krb5_pac_verify(context, + pac, + o->ticket->ticket.authtime, + o->ticket->client, + o->keyblock, + NULL); + if (ret == 0) + o->ticket->client->nameattrs->pac_verified = 1; + if (ret == 0 && (context->flags & KRB5_CTX_F_REPORT_CANONICAL_CLIENT_NAME)) { + krb5_error_code ret2; + krb5_principal canon_name; + + ret2 = _krb5_pac_get_canon_principal(context, pac, &canon_name); + if (ret2 == 0) { + free_Realm(&o->ticket->client->realm); + free_PrincipalName(&o->ticket->client->name); + ret = copy_Realm(&canon_name->realm, &o->ticket->client->realm); + if (ret == 0) + ret = copy_PrincipalName(&canon_name->name, &o->ticket->client->name); + krb5_free_principal(context, canon_name); + } else if (ret2 != ENOENT) + ret = ret2; + } + if (ret) { + krb5_pac_free(context, pac); + goto out; + } + o->ticket->client->nameattrs->pac = pac; + } else + ret = 0; + } +out: + + if (ret || outctx == NULL) + krb5_rd_req_out_ctx_free(context, o); + else + *outctx = o; + + free_AP_REQ(&ap_req); + + if (service) + krb5_free_principal(context, service); + + if (keytab) + krb5_kt_close(context, keytab); + + return ret; +} |