/
kdc_util.c
1477 lines (1331 loc) · 43.8 KB
/
kdc_util.c
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/*
* kdc/kdc_util.c
*
* Copyright 1990,1991 by the Massachusetts Institute of Technology.
* All Rights Reserved.
*
* Export of this software from the United States of America may
* require a specific license from the United States Government.
* It is the responsibility of any person or organization contemplating
* export to obtain such a license before exporting.
*
* WITHIN THAT CONSTRAINT, permission to use, copy, modify, and
* distribute this software and its documentation for any purpose and
* without fee is hereby granted, provided that the above copyright
* notice appear in all copies and that both that copyright notice and
* this permission notice appear in supporting documentation, and that
* the name of M.I.T. not be used in advertising or publicity pertaining
* to distribution of the software without specific, written prior
* permission. M.I.T. makes no representations about the suitability of
* this software for any purpose. It is provided "as is" without express
* or implied warranty.
*
*
* Utility functions for the KDC implementation.
*/
#include "k5-int.h"
#include "kdc_util.h"
#include "extern.h"
#include <stdio.h>
#include <syslog.h>
#include "adm.h"
#include "adm_proto.h"
/*
* concatenate first two authdata arrays, returning an allocated replacement.
* The replacement should be freed with krb5_free_authdata().
*/
krb5_error_code
concat_authorization_data(first, second, output)
krb5_authdata **first;
krb5_authdata **second;
krb5_authdata ***output;
{
register int i, j;
register krb5_authdata **ptr, **retdata;
/* count up the entries */
i = 0;
if (first)
for (ptr = first; *ptr; ptr++)
i++;
if (second)
for (ptr = second; *ptr; ptr++)
i++;
retdata = (krb5_authdata **)malloc((i+1)*sizeof(*retdata));
if (!retdata)
return ENOMEM;
retdata[i] = 0; /* null-terminated array */
for (i = 0, j = 0, ptr = first; j < 2 ; ptr = second, j++)
while (ptr && *ptr) {
/* now walk & copy */
retdata[i] = (krb5_authdata *)malloc(sizeof(*retdata[i]));
if (!retdata[i]) {
krb5_free_authdata(kdc_context, retdata);
return ENOMEM;
}
*retdata[i] = **ptr;
if (!(retdata[i]->contents =
(krb5_octet *)malloc(retdata[i]->length))) {
free((char *)retdata[i]);
retdata[i] = 0;
krb5_free_authdata(kdc_context, retdata);
return ENOMEM;
}
memcpy((char *) retdata[i]->contents,
(char *)(*ptr)->contents,
retdata[i]->length);
ptr++;
i++;
}
*output = retdata;
return 0;
}
krb5_boolean
realm_compare(princ1, princ2)
krb5_principal princ1;
krb5_principal princ2;
{
krb5_data *realm1 = krb5_princ_realm(kdc_context, princ1);
krb5_data *realm2 = krb5_princ_realm(kdc_context, princ2);
return((realm1->length == realm2->length) &&
!memcmp(realm1->data, realm2->data, realm1->length));
}
/*
* Returns TRUE if the kerberos principal is the name of a Kerberos ticket
* service.
*/
krb5_boolean krb5_is_tgs_principal(principal)
krb5_principal principal;
{
if ((krb5_princ_component(kdc_context, principal, 0)->length ==
KRB5_TGS_NAME_SIZE) &&
(!memcmp(krb5_princ_component(kdc_context, principal, 0)->data,
KRB5_TGS_NAME, KRB5_TGS_NAME_SIZE)))
return TRUE;
return FALSE;
}
/*
* given authentication data (provides seed for checksum), verify checksum
* for source data.
*/
static krb5_error_code
comp_cksum(kcontext, source, ticket, his_cksum)
krb5_context kcontext;
krb5_data * source;
krb5_ticket * ticket;
krb5_checksum * his_cksum;
{
krb5_error_code retval;
krb5_boolean valid;
if (!valid_cksumtype(his_cksum->checksum_type))
return KRB5KDC_ERR_SUMTYPE_NOSUPP;
/* must be collision proof */
if (!is_coll_proof_cksum(his_cksum->checksum_type))
return KRB5KRB_AP_ERR_INAPP_CKSUM;
/* verify checksum */
if ((retval = krb5_c_verify_checksum(kcontext, ticket->enc_part2->session,
KRB5_KEYUSAGE_TGS_REQ_AUTH_CKSUM,
source, his_cksum, &valid)))
return(retval);
if (!valid)
return(KRB5KRB_AP_ERR_BAD_INTEGRITY);
return(0);
}
krb5_error_code
kdc_process_tgs_req(request, from, pkt, ticket, subkey)
krb5_kdc_req * request;
const krb5_fulladdr * from;
krb5_data * pkt;
krb5_ticket ** ticket;
krb5_keyblock ** subkey;
{
krb5_pa_data ** tmppa;
krb5_ap_req * apreq;
krb5_error_code retval;
krb5_data scratch1;
krb5_data * scratch = NULL;
krb5_boolean foreign_server = FALSE;
krb5_auth_context auth_context = NULL;
krb5_authenticator * authenticator = NULL;
krb5_checksum * his_cksum = NULL;
krb5_keyblock * key = NULL;
krb5_kvno kvno = 0;
if (!request->padata)
return KRB5KDC_ERR_PADATA_TYPE_NOSUPP;
for (tmppa = request->padata; *tmppa; tmppa++) {
if ((*tmppa)->pa_type == KRB5_PADATA_AP_REQ)
break;
}
if (!*tmppa) /* cannot find any AP_REQ */
return KRB5KDC_ERR_PADATA_TYPE_NOSUPP;
scratch1.length = (*tmppa)->length;
scratch1.data = (char *)(*tmppa)->contents;
if ((retval = decode_krb5_ap_req(&scratch1, &apreq)))
return retval;
if (isflagset(apreq->ap_options, AP_OPTS_USE_SESSION_KEY) ||
isflagset(apreq->ap_options, AP_OPTS_MUTUAL_REQUIRED)) {
krb5_klog_syslog(LOG_INFO, "TGS_REQ: SESSION KEY or MUTUAL");
retval = KRB5KDC_ERR_POLICY;
goto cleanup;
}
/* If the "server" principal in the ticket is not something
in the local realm, then we must refuse to service the request
if the client claims to be from the local realm.
If we don't do this, then some other realm's nasty KDC can
claim to be authenticating a client from our realm, and we'll
give out tickets concurring with it!
we set a flag here for checking below.
*/
if ((krb5_princ_realm(kdc_context, apreq->ticket->server)->length !=
krb5_princ_realm(kdc_context, tgs_server)->length) ||
memcmp(krb5_princ_realm(kdc_context, apreq->ticket->server)->data,
krb5_princ_realm(kdc_context, tgs_server)->data,
krb5_princ_realm(kdc_context, tgs_server)->length))
foreign_server = TRUE;
if ((retval = krb5_auth_con_init(kdc_context, &auth_context)))
goto cleanup;
if ((retval = krb5_auth_con_setaddrs(kdc_context, auth_context, NULL,
from->address)) )
goto cleanup_auth_context;
#ifdef USE_RCACHE
if ((retval = krb5_auth_con_setrcache(kdc_context, auth_context,
kdc_rcache)))
goto cleanup_auth_context;
#endif
/*
if ((retval = kdc_get_server_key(apreq->ticket, &key, &kvno)))
goto cleanup_auth_context;
*/
/*
* XXX This is currently wrong but to fix it will require making a
* new keytab for groveling over the kdb.
*/
/*
retval = krb5_auth_con_setuseruserkey(kdc_context, auth_context, key);
krb5_free_keyblock(kdc_context, key);
if (retval)
goto cleanup_auth_context;
*/
if ((retval = krb5_rd_req_decoded_anyflag(kdc_context, &auth_context, apreq,
apreq->ticket->server,
kdc_active_realm->realm_keytab,
NULL, ticket))) {
#ifdef USE_RCACHE
/*
* I'm not so sure that this is right, but it's better than nothing
* at all.
*
* If we choke in the rd_req because of the replay cache, then attempt
* to reinitialize the replay cache because somebody could have deleted
* it from underneath us (e.g. a cron job)
*/
if ((retval == KRB5_RC_IO_IO) ||
(retval == KRB5_RC_IO_UNKNOWN)) {
(void) krb5_rc_close(kdc_context, kdc_rcache);
kdc_rcache = (krb5_rcache) NULL;
if (!(retval = kdc_initialize_rcache(kdc_context, (char *) NULL))) {
if ((retval = krb5_auth_con_setrcache(kdc_context, auth_context,
kdc_rcache)) ||
(retval = krb5_rd_req_decoded_anyflag(kdc_context, &auth_context,
apreq, apreq->ticket->server,
kdc_active_realm->realm_keytab,
NULL, ticket))
)
goto cleanup_auth_context;
}
} else
goto cleanup_auth_context;
#else
goto cleanup_auth_context;
#endif
}
/* "invalid flag" tickets can must be used to validate */
if (isflagset((*ticket)->enc_part2->flags, TKT_FLG_INVALID)
&& !isflagset(request->kdc_options, KDC_OPT_VALIDATE)) {
retval = KRB5KRB_AP_ERR_TKT_INVALID;
goto cleanup_auth_context;
}
if ((retval = krb5_auth_con_getremotesubkey(kdc_context,
auth_context, subkey)))
goto cleanup_auth_context;
if ((retval = krb5_auth_con_getauthenticator(kdc_context, auth_context,
&authenticator)))
goto cleanup_auth_context;
/* Check for a checksum */
if (!(his_cksum = authenticator->checksum)) {
retval = KRB5KRB_AP_ERR_INAPP_CKSUM;
goto cleanup_authenticator;
}
/* make sure the client is of proper lineage (see above) */
if (foreign_server) {
krb5_data *tkt_realm = krb5_princ_realm(kdc_context,
(*ticket)->enc_part2->client);
krb5_data *tgs_realm = krb5_princ_realm(kdc_context, tgs_server);
if (tkt_realm->length == tgs_realm->length &&
!memcmp(tkt_realm->data, tgs_realm->data, tgs_realm->length)) {
/* someone in a foreign realm claiming to be local */
krb5_klog_syslog(LOG_INFO, "PROCESS_TGS: failed lineage check");
retval = KRB5KDC_ERR_POLICY;
goto cleanup_authenticator;
}
}
/*
* Check application checksum vs. tgs request
*
* We try checksumming the req-body two different ways: first we
* try reaching into the raw asn.1 stream (if available), and
* checksum that directly; if that fails, then we try encoding
* using our local asn.1 library.
*/
if (pkt && (fetch_asn1_field((unsigned char *) pkt->data,
1, 4, &scratch1) >= 0)) {
if (comp_cksum(kdc_context, &scratch1, *ticket, his_cksum)) {
if (!(retval = encode_krb5_kdc_req_body(request, &scratch)))
retval = comp_cksum(kdc_context, scratch, *ticket, his_cksum);
krb5_free_data(kdc_context, scratch);
}
}
cleanup_authenticator:
krb5_free_authenticator(kdc_context, authenticator);
cleanup_auth_context:
/* We do not want the free of the auth_context to close the rcache */
#ifdef USE_RCACHE
(void) krb5_auth_con_setrcache(kdc_context, auth_context, 0);
#endif
krb5_auth_con_free(kdc_context, auth_context);
cleanup:
krb5_free_ap_req(kdc_context, apreq);
return retval;
}
/* XXX This function should no longer be necessary.
* The KDC should take the keytab associated with the realm and pass that to
* the krb5_rd_req_decode(). --proven
*
* It's actually still used by do_tgs_req() for u2u auth, and not too
* much else. -- tlyu
*/
krb5_error_code
kdc_get_server_key(ticket, key, kvno)
krb5_ticket * ticket;
krb5_keyblock ** key;
krb5_kvno * kvno; /* XXX nothing uses this */
{
krb5_error_code retval;
krb5_db_entry server;
krb5_boolean more;
int nprincs;
krb5_key_data * server_key;
int i;
nprincs = 1;
if ((retval = krb5_db_get_principal(kdc_context, ticket->server,
&server, &nprincs,
&more))) {
return(retval);
}
if (more) {
krb5_db_free_principal(kdc_context, &server, nprincs);
return(KRB5KDC_ERR_PRINCIPAL_NOT_UNIQUE);
} else if (nprincs != 1) {
char *sname;
krb5_db_free_principal(kdc_context, &server, nprincs);
if (!krb5_unparse_name(kdc_context, ticket->server, &sname)) {
krb5_klog_syslog(LOG_ERR,"TGS_REQ: UNKNOWN SERVER: server='%s'",
sname);
free(sname);
}
return(KRB5KDC_ERR_S_PRINCIPAL_UNKNOWN);
}
retval = krb5_dbe_find_enctype(kdc_context, &server,
ticket->enc_part.enctype, -1,
ticket->enc_part.kvno, &server_key);
if (retval)
goto errout;
if (!server_key) {
retval = KRB5KDC_ERR_S_PRINCIPAL_UNKNOWN;
goto errout;
}
*kvno = server_key->key_data_kvno;
if ((*key = (krb5_keyblock *)malloc(sizeof **key))) {
retval = krb5_dbekd_decrypt_key_data(kdc_context, &master_keyblock,
server_key,
*key, NULL);
} else
retval = ENOMEM;
errout:
krb5_db_free_principal(kdc_context, &server, nprincs);
return retval;
}
/* This probably wants to be updated if you support last_req stuff */
static krb5_last_req_entry nolrentry = { KV5M_LAST_REQ_ENTRY, KRB5_LRQ_NONE, 0 };
static krb5_last_req_entry *nolrarray[] = { &nolrentry, 0 };
krb5_error_code
fetch_last_req_info(dbentry, lrentry)
krb5_db_entry *dbentry;
krb5_last_req_entry ***lrentry;
{
*lrentry = nolrarray;
return 0;
}
/* XXX! This is a temporary place-holder */
krb5_error_code
check_hot_list(ticket)
krb5_ticket *ticket;
{
return 0;
}
#define MAX_REALM_LN 500
/*
* subrealm - determine if r2 is a subrealm of r1
*
* SUBREALM takes two realms, r1 and r2, and
* determines if r2 is a subrealm of r1.
* r2 is a subrealm of r1 if (r1 is a prefix
* of r2 AND r1 and r2 begin with a /) or if
* (r1 is a suffix of r2 and neither r1 nor r2
* begin with a /).
*
* RETURNS: If r2 is a subrealm, and r1 is a prefix, the number
* of characters in the suffix of r2 is returned as a
* negative number.
*
* If r2 is a subrealm, and r1 is a suffix, the number
* of characters in the prefix of r2 is returned as a
* positive number.
*
* If r2 is not a subrealm, SUBREALM returns 0.
*/
static int
subrealm(r1,r2)
char *r1;
char *r2;
{
int l1,l2;
l1 = strlen(r1);
l2 = strlen(r2);
if(l2 <= l1) return(0);
if((*r1 == '/') && (*r2 == '/') && (strncmp(r1,r2,l1) == 0)) return(l1-l2);
if((*r1 != '/') && (*r2 != '/') && (strncmp(r1,r2+l2-l1,l1) == 0))
return(l2-l1);
return(0);
}
/*
* add_to_transited Adds the name of the realm which issued the
* ticket granting ticket on which the new ticket to
* be issued is based (note that this is the same as
* the realm of the server listed in the ticket
* granting ticket.
*
* ASSUMPTIONS: This procedure assumes that the transited field from
* the existing ticket granting ticket already appears
* in compressed form. It will add the new realm while
* maintaining that form. As long as each successive
* realm is added using this (or a similar) routine, the
* transited field will be in compressed form. The
* basis step is an empty transited field which is, by
* its nature, in its most compressed form.
*
* ARGUMENTS: krb5_data *tgt_trans Transited field from TGT
* krb5_data *new_trans The transited field for the new ticket
* krb5_principal tgs Name of ticket granting server
* This includes the realm of the KDC
* that issued the ticket granting
* ticket. This is the realm that is
* to be added to the transited field.
* krb5_principal client Name of the client
* krb5_principal server The name of the requested server.
* This may be the an intermediate
* ticket granting server.
*
* The last two argument are needed since they are
* implicitly part of the transited field of the new ticket
* even though they are not explicitly listed.
*
* RETURNS: krb5_error_code - Success, or out of memory
*
* MODIFIES: new_trans: ->length will contain the length of the new
* transited field.
*
* If ->data was not null when this procedure
* is called, the memory referenced by ->data
* will be deallocated.
*
* Memory will be allocated for the new transited field
* ->data will be updated to point to the newly
* allocated memory.
*
* BUGS: The space allocated for the new transited field is the
* maximum that might be needed given the old transited field,
* and the realm to be added. This length is calculated
* assuming that no compression of the new realm is possible.
* This has no adverse consequences other than the allocation
* of more space than required.
*
* This procedure will not yet use the null subfield notation,
* and it will get confused if it sees it.
*
* This procedure does not check for quoted commas in realm
* names.
*/
krb5_error_code
add_to_transited(tgt_trans, new_trans, tgs, client, server)
krb5_data * tgt_trans;
krb5_data * new_trans;
krb5_principal tgs;
krb5_principal client;
krb5_principal server;
{
krb5_error_code retval;
char *realm;
char *trans;
char *otrans, *otrans_ptr;
/* The following are for stepping through the transited field */
char prev[MAX_REALM_LN];
char next[MAX_REALM_LN];
char current[MAX_REALM_LN];
char exp[MAX_REALM_LN]; /* Expanded current realm name */
int i;
int clst, nlst; /* count of last character in current and next */
int pl, pl1; /* prefix length */
int added; /* TRUE = new realm has been added */
if (!(realm = (char *) malloc(krb5_princ_realm(kdc_context, tgs)->length+1))) {
return(ENOMEM);
}
memcpy(realm, krb5_princ_realm(kdc_context, tgs)->data,
krb5_princ_realm(kdc_context, tgs)->length);
realm[krb5_princ_realm(kdc_context, tgs)->length] = '\0';
if (!(otrans = (char *) malloc(tgt_trans->length+1))) {
free(realm);
return(ENOMEM);
}
memcpy(otrans, tgt_trans->data, tgt_trans->length);
otrans[tgt_trans->length] = '\0';
/* Keep track of start so we can free */
otrans_ptr = otrans;
/* +1 for null,
+1 for extra comma which may be added between
+1 for potential space when leading slash in realm */
if (!(trans = (char *) malloc(strlen(realm) + strlen(otrans) + 3))) {
retval = ENOMEM;
goto fail;
}
if (new_trans->data) free(new_trans->data);
new_trans->data = trans;
new_trans->length = 0;
trans[0] = '\0';
/* For the purpose of appending, the realm preceding the first */
/* realm in the transited field is considered the null realm */
prev[0] = '\0';
/* read field into current */
for (i = 0; *otrans != '\0';) {
if (*otrans == '\\')
if (*(++otrans) == '\0')
break;
else
continue;
if (*otrans == ',') {
otrans++;
break;
}
current[i++] = *otrans++;
if (i >= MAX_REALM_LN) {
retval = KRB5KRB_AP_ERR_ILL_CR_TKT;
goto fail;
}
}
current[i] = '\0';
added = (krb5_princ_realm(kdc_context, client)->length == strlen(realm) &&
!strncmp(krb5_princ_realm(kdc_context, client)->data, realm, strlen(realm))) ||
(krb5_princ_realm(kdc_context, server)->length == strlen(realm) &&
!strncmp(krb5_princ_realm(kdc_context, server)->data, realm, strlen(realm)));
while (current[0]) {
/* figure out expanded form of current name */
clst = strlen(current) - 1;
if (current[0] == ' ') {
strcpy(exp, current+1);
}
else if ((current[0] == '/') && (prev[0] == '/')) {
strcpy(exp, prev);
if (strlen(exp) + strlen(current) + 1 >= MAX_REALM_LN) {
retval = KRB5KRB_AP_ERR_ILL_CR_TKT;
goto fail;
}
strcat(exp, current);
}
else if (current[clst] == '.') {
strcpy(exp, current);
if (strlen(exp) + strlen(current) + 1 >= MAX_REALM_LN) {
retval = KRB5KRB_AP_ERR_ILL_CR_TKT;
goto fail;
}
strcat(exp, prev);
}
else {
strcpy(exp, current);
}
/* read field into next */
for (i = 0; *otrans != '\0';) {
if (*otrans == '\\')
if (*(++otrans) == '\0')
break;
else
continue;
if (*otrans == ',') {
otrans++;
break;
}
next[i++] = *otrans++;
if (i >= MAX_REALM_LN) {
retval = KRB5KRB_AP_ERR_ILL_CR_TKT;
goto fail;
}
}
next[i] = '\0';
nlst = i - 1;
if (!strcmp(exp, realm)) added = TRUE;
/* If we still have to insert the new realm */
if (!added) {
/* Is the next field compressed? If not, and if the new */
/* realm is a subrealm of the current realm, compress */
/* the new realm, and insert immediately following the */
/* current one. Note that we can not do this if the next*/
/* field is already compressed since it would mess up */
/* what has already been done. In most cases, this is */
/* not a problem because the realm to be added will be a */
/* subrealm of the next field too, and we will catch */
/* it in a future iteration. */
if ((next[nlst] != '.') && (next[0] != '/') &&
(pl = subrealm(exp, realm))) {
added = TRUE;
if (strlen(current) + (pl>0?pl:-pl) + 2 >= MAX_REALM_LN) {
retval = KRB5KRB_AP_ERR_ILL_CR_TKT;
goto fail;
}
strcat(current, ",");
if (pl > 0) {
strncat(current, realm, pl);
}
else {
strncat(current, realm+strlen(realm)+pl, -pl);
}
}
/* Whether or not the next field is compressed, if the */
/* realm to be added is a superrealm of the current realm,*/
/* then the current realm can be compressed. First the */
/* realm to be added must be compressed relative to the */
/* previous realm (if possible), and then the current */
/* realm compressed relative to the new realm. Note that */
/* if the realm to be added is also a superrealm of the */
/* previous realm, it would have been added earlier, and */
/* we would not reach this step this time around. */
else if ((pl = subrealm(realm, exp))) {
added = TRUE;
current[0] = '\0';
if ((pl1 = subrealm(prev,realm))) {
if (strlen(current) + (pl1>0?pl1:-pl1) + 1 >= MAX_REALM_LN) {
retval = KRB5KRB_AP_ERR_ILL_CR_TKT;
goto fail;
}
if (pl1 > 0) {
strncat(current, realm, pl1);
}
else {
strncat(current, realm+strlen(realm)+pl1, -pl1);
}
}
else { /* If not a subrealm */
if ((realm[0] == '/') && prev[0]) {
if (strlen(current) + 2 >= MAX_REALM_LN) {
retval = KRB5KRB_AP_ERR_ILL_CR_TKT;
goto fail;
}
strcat(current, " ");
}
if (strlen(current) + strlen(realm) + 1 >= MAX_REALM_LN) {
retval = KRB5KRB_AP_ERR_ILL_CR_TKT;
goto fail;
}
strcat(current, realm);
}
if (strlen(current) + (pl>0?pl:-pl) + 2 >= MAX_REALM_LN) {
retval = KRB5KRB_AP_ERR_ILL_CR_TKT;
goto fail;
}
strcat(current,",");
if (pl > 0) {
strncat(current, exp, pl);
}
else {
strncat(current, exp+strlen(exp)+pl, -pl);
}
}
}
if (new_trans->length != 0) {
if (strlen(trans) + 2 >= MAX_REALM_LN) {
retval = KRB5KRB_AP_ERR_ILL_CR_TKT;
goto fail;
}
strcat(trans, ",");
}
if (strlen(trans) + strlen(current) + 1 >= MAX_REALM_LN) {
retval = KRB5KRB_AP_ERR_ILL_CR_TKT;
goto fail;
}
strcat(trans, current);
new_trans->length = strlen(trans) + 1;
strcpy(prev, exp);
strcpy(current, next);
}
if (!added) {
if (new_trans->length != 0) {
if (strlen(trans) + 2 >= MAX_REALM_LN) {
retval = KRB5KRB_AP_ERR_ILL_CR_TKT;
goto fail;
}
strcat(trans, ",");
}
if((realm[0] == '/') && trans[0]) {
if (strlen(trans) + 2 >= MAX_REALM_LN) {
retval = KRB5KRB_AP_ERR_ILL_CR_TKT;
goto fail;
}
strcat(trans, " ");
}
if (strlen(trans) + strlen(realm) + 1 >= MAX_REALM_LN) {
retval = KRB5KRB_AP_ERR_ILL_CR_TKT;
goto fail;
}
strcat(trans, realm);
new_trans->length = strlen(trans) + 1;
}
retval = 0;
fail:
free(realm);
free(otrans_ptr);
return (retval);
}
/*
* Routines that validate a AS request; checks a lot of things. :-)
*
* Returns a Kerberos protocol error number, which is _not_ the same
* as a com_err error number!
*/
#define AS_OPTIONS_HANDLED (KDC_OPT_FORWARDABLE | KDC_OPT_PROXIABLE | \
KDC_OPT_ALLOW_POSTDATE | KDC_OPT_POSTDATED | \
KDC_OPT_RENEWABLE | KDC_OPT_RENEWABLE_OK)
int
validate_as_request(request, client, server, kdc_time, status)
register krb5_kdc_req *request;
krb5_db_entry client;
krb5_db_entry server;
krb5_timestamp kdc_time;
const char **status;
{
int errcode;
/*
* If an illegal option is set, complain.
*/
if (request->kdc_options & ~(AS_OPTIONS_HANDLED)) {
*status = "INVALID AS OPTIONS";
return KDC_ERR_BADOPTION;
}
/* The client's password must not be expired, unless the server is
a KRB5_KDC_PWCHANGE_SERVICE. */
if (client.pw_expiration && client.pw_expiration < kdc_time &&
!isflagset(server.attributes, KRB5_KDB_PWCHANGE_SERVICE)) {
*status = "CLIENT KEY EXPIRED";
#ifdef KRBCONF_VAGUE_ERRORS
return(KRB_ERR_GENERIC);
#else
return(KDC_ERR_KEY_EXP);
#endif
}
/* The client must not be expired */
if (client.expiration && client.expiration < kdc_time) {
*status = "CLIENT EXPIRED";
#ifdef KRBCONF_VAGUE_ERRORS
return(KRB_ERR_GENERIC);
#else
return(KDC_ERR_NAME_EXP);
#endif
}
/* The server must not be expired */
if (server.expiration && server.expiration < kdc_time) {
*status = "SERVICE EXPIRED";
return(KDC_ERR_SERVICE_EXP);
}
/*
* If the client requires password changing, then only allow the
* pwchange service.
*/
if (isflagset(client.attributes, KRB5_KDB_REQUIRES_PWCHANGE) &&
!isflagset(server.attributes, KRB5_KDB_PWCHANGE_SERVICE)) {
*status = "REQUIRED PWCHANGE";
return(KDC_ERR_KEY_EXP);
}
/* Client and server must allow postdating tickets */
if ((isflagset(request->kdc_options, KDC_OPT_ALLOW_POSTDATE) ||
isflagset(request->kdc_options, KDC_OPT_POSTDATED)) &&
(isflagset(client.attributes, KRB5_KDB_DISALLOW_POSTDATED) ||
isflagset(server.attributes, KRB5_KDB_DISALLOW_POSTDATED))) {
*status = "POSTDATE NOT ALLOWED";
return(KDC_ERR_CANNOT_POSTDATE);
}
/* Client and server must allow forwardable tickets */
if (isflagset(request->kdc_options, KDC_OPT_FORWARDABLE) &&
(isflagset(client.attributes, KRB5_KDB_DISALLOW_FORWARDABLE) ||
isflagset(server.attributes, KRB5_KDB_DISALLOW_FORWARDABLE))) {
*status = "FORWARDABLE NOT ALLOWED";
return(KDC_ERR_POLICY);
}
/* Client and server must allow renewable tickets */
if (isflagset(request->kdc_options, KDC_OPT_RENEWABLE) &&
(isflagset(client.attributes, KRB5_KDB_DISALLOW_RENEWABLE) ||
isflagset(server.attributes, KRB5_KDB_DISALLOW_RENEWABLE))) {
*status = "RENEWABLE NOT ALLOWED";
return(KDC_ERR_POLICY);
}
/* Client and server must allow proxiable tickets */
if (isflagset(request->kdc_options, KDC_OPT_PROXIABLE) &&
(isflagset(client.attributes, KRB5_KDB_DISALLOW_PROXIABLE) ||
isflagset(server.attributes, KRB5_KDB_DISALLOW_PROXIABLE))) {
*status = "PROXIABLE NOT ALLOWED";
return(KDC_ERR_POLICY);
}
/* Check to see if client is locked out */
if (isflagset(client.attributes, KRB5_KDB_DISALLOW_ALL_TIX)) {
*status = "CLIENT LOCKED OUT";
return(KDC_ERR_C_PRINCIPAL_UNKNOWN);
}
/* Check to see if server is locked out */
if (isflagset(server.attributes, KRB5_KDB_DISALLOW_ALL_TIX)) {
*status = "SERVICE LOCKED OUT";
return(KDC_ERR_S_PRINCIPAL_UNKNOWN);
}
/* Check to see if server is allowed to be a service */
if (isflagset(server.attributes, KRB5_KDB_DISALLOW_SVR)) {
*status = "SERVICE NOT ALLOWED";
return(KDC_ERR_S_PRINCIPAL_UNKNOWN);
}
/*
* Check against local policy
*/
errcode = against_local_policy_as(request, server, client,
kdc_time, status);
if (errcode)
return errcode;
return 0;
}
#define ASN1_ID_CLASS (0xc0)
#define ASN1_ID_TYPE (0x20)
#define ASN1_ID_TAG (0x1f)
#define ASN1_CLASS_UNIV (0)
#define ASN1_CLASS_APP (1)
#define ASN1_CLASS_CTX (2)
#define ASN1_CLASS_PRIV (3)
#define asn1_id_constructed(x) (x & ASN1_ID_TYPE)
#define asn1_id_primitive(x) (!asn1_id_constructed(x))
#define asn1_id_class(x) ((x & ASN1_ID_CLASS) >> 6)
#define asn1_id_tag(x) (x & ASN1_ID_TAG)
/*
* asn1length - return encoded length of value.
*
* passed a pointer into the asn.1 stream, which is updated
* to point right after the length bits.
*
* returns -1 on failure.
*/
static int
asn1length(astream)
unsigned char **astream;
{
int length; /* resulting length */
int sublen; /* sublengths */
int blen; /* bytes of length */
unsigned char *p; /* substring searching */
if (**astream & 0x80) {
blen = **astream & 0x7f;
if (blen > 3) {
return(-1);
}
for (++*astream, length = 0; blen; ++*astream, blen--) {
length = (length << 8) | **astream;
}
if (length == 0) {
/* indefinite length, figure out by hand */
p = *astream;
p++;
while (1) {
/* compute value length. */
if ((sublen = asn1length(&p)) < 0) {
return(-1);
}
p += sublen;
/* check for termination */
if ((!*p++) && (!*p)) {
p++;
break;
}
}
length = p - *astream;
}
} else {
length = **astream;
++*astream;
}
return(length);
}
/*
* fetch_asn1_field - return raw asn.1 stream of subfield.
*
* this routine is passed a context-dependent tag number and "level" and returns
* the size and length of the corresponding level subfield.
*
* levels and are numbered starting from 1.
*
* returns 0 on success, -1 otherwise.
*/
int
fetch_asn1_field(astream, level, field, data)
unsigned char *astream;
unsigned int level;
unsigned int field;
krb5_data *data;
{
unsigned char *estream; /* end of stream */
int classes; /* # classes seen so far this level */
unsigned int levels = 0; /* levels seen so far */
int lastlevel = 1000; /* last level seen */
int length; /* various lengths */
int tag; /* tag number */
unsigned char savelen; /* saved length of our field */
classes = -1;
/* we assume that the first identifier/length will tell us
how long the entire stream is. */