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/*
* lib/krb5/krb/walk_rtree.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. Furthermore if you modify this software you must label
* your software as modified software and not distribute it in such a
* fashion that it might be confused with the original M.I.T. software.
* 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.
*
*
* krb5_walk_realm_tree()
*/
/* ANL - Modified to allow Configurable Authentication Paths.
* This modification removes the restriction on the choice of realm
* names, i.e. they nolonger have to be hierarchical. This
* is allowed by RFC 1510: "If a hierarchical orginization is not used
* it may be necessary to consult some database in order to construct
* an authentication path between realms." The database is contained
* in the [capaths] section of the krb5.conf file.
* Client to server paths are defined. There are n**2 possible
* entries, but only those entries which are needed by the client
* or server need be present in its krb5.conf file. (n entries or 2*n
* entries if the same krb5.conf is used for clients and servers)
*
* for example: ESnet will be running a KDC which will share
* inter-realm keys with its many orginizations which include among
* other ANL, NERSC and PNL. Each of these orginizations wants to
* use its DNS name in the realm, ANL.GOV. In addition ANL wants
* to authenticatite to HAL.COM via a K5.MOON and K5.JUPITER
* A [capaths] section of the krb5.conf file for the ANL.GOV clients
* and servers would look like:
*
* [capaths]
* ANL.GOV = {
* NERSC.GOV = ES.NET
* PNL.GOV = ES.NET
* ES.NET = .
* HAL.COM = K5.MOON
* HAL.COM = K5.JUPITER
* }
* NERSC.GOV = {
* ANL.GOV = ES.NET
* }
* PNL.GOV = {
* ANL.GOV = ES.NET
* }
* ES.NET = {
* ANL.GOV = .
* }
* HAL.COM = {
* ANL.GOV = K5.JUPITER
* ANL.GOV = K5.MOON
* }
*
* In the above a "." is used to mean directly connected since the
* the profile routines cannot handle a null entry.
*
* If no client-to-server path is found, the default hierarchical path
* is still generated.
*
* This version of the Configurable Authentication Path modification
* differs from the previous versions prior to K5 beta 5 in that
* the profile routines are used, and the explicite path from
* client's realm to server's realm must be given. The modifications
* will work together.
* DEE - 5/23/95
*/
#define CONFIGURABLE_AUTHENTICATION_PATH
#include "k5-int.h"
#include "int-proto.h"
/* internal function, used by krb5_get_cred_from_kdc() */
#ifndef min
#define min(x,y) ((x) < (y) ? (x) : (y))
#define max(x,y) ((x) > (y) ? (x) : (y))
#endif
krb5_error_code
krb5_walk_realm_tree(context, client, server, tree, realm_branch_char)
krb5_context context;
const krb5_data *client, *server;
krb5_principal **tree;
int realm_branch_char;
{
krb5_error_code retval;
krb5_principal *rettree;
register char *ccp, *scp;
register char *prevccp = 0, *prevscp = 0;
char *com_sdot = 0, *com_cdot = 0;
register int i, links = 0;
int clen, slen = -1;
krb5_data tmpcrealm, tmpsrealm;
int nocommon = 1;
#ifdef CONFIGURABLE_AUTHENTICATION_PATH
const char *cap_names[4];
char *cap_client, *cap_server;
char **cap_nodes;
krb5_error_code cap_code;
if ((cap_client = (char *)malloc(client->length + 1)) == NULL)
return ENOMEM;
strncpy(cap_client, client->data, client->length);
cap_client[client->length] = '\0';
if ((cap_server = (char *)malloc(server->length + 1)) == NULL) {
krb5_xfree(cap_client);
return ENOMEM;
}
strncpy(cap_server, server->data, server->length);
cap_server[server->length] = '\0';
cap_names[0] = "capaths";
cap_names[1] = cap_client;
cap_names[2] = cap_server;
cap_names[3] = 0;
cap_code = profile_get_values(context->profile, cap_names, &cap_nodes);
krb5_xfree(cap_client); /* done with client string */
cap_names[1] = 0;
if (cap_code == 0) { /* found a path, so lets use it */
links = 0;
if (*cap_nodes[0] != '.') { /* a link of . means direct */
while(cap_nodes[links]) {
links++;
}
}
cap_nodes[links] = cap_server; /* put server on end of list */
/* this simplifies the code later and make */
/* cleanup eaiser as well */
links++; /* count the null entry at end */
} else { /* no path use hierarchical method */
krb5_xfree(cap_server); /* failed, don't need server string */
cap_names[2] = 0;
#endif
clen = client->length;
slen = server->length;
for (com_cdot = ccp = client->data + clen - 1,
com_sdot = scp = server->data + slen - 1;
clen && slen && *ccp == *scp ;
ccp--, scp--, clen--, slen--) {
if (*ccp == realm_branch_char) {
com_cdot = ccp;
com_sdot = scp;
nocommon = 0;
}
}
/* ccp, scp point to common root.
com_cdot, com_sdot point to common components. */
/* handle case of one ran out */
if (!clen) {
/* construct path from client to server, down the tree */
if (!slen)
/* in the same realm--this means there is no ticket
in this realm. */
return KRB5_NO_TKT_IN_RLM;
if (*scp == realm_branch_char) {
/* one is a subdomain of the other */
com_cdot = client->data;
com_sdot = scp;
nocommon = 0;
} /* else normal case of two sharing parents */
}
if (!slen) {
/* construct path from client to server, up the tree */
if (*ccp == realm_branch_char) {
/* one is a subdomain of the other */
com_sdot = server->data;
com_cdot = ccp;
nocommon = 0;
} /* else normal case of two sharing parents */
}
/* determine #links to/from common ancestor */
if (nocommon)
links = 1;
else
links = 2;
/* if no common ancestor, artificially set up common root at the last
component, then join with special code */
for (ccp = client->data; ccp < com_cdot; ccp++) {
if (*ccp == realm_branch_char) {
links++;
if (nocommon)
prevccp = ccp;
}
}
for (scp = server->data; scp < com_sdot; scp++) {
if (*scp == realm_branch_char) {
links++;
if (nocommon)
prevscp = scp;
}
}
if (nocommon) {
if (prevccp)
com_cdot = prevccp;
if (prevscp)
com_sdot = prevscp;
if(com_cdot == client->data + client->length -1)
com_cdot = client->data - 1 ;
if(com_sdot == server->data + server->length -1)
com_sdot = server->data - 1 ;
}
#ifdef CONFIGURABLE_AUTHENTICATION_PATH
} /* end of if use hierarchical method */
#endif
if (!(rettree = (krb5_principal *)calloc(links+2,
sizeof(krb5_principal)))) {
return ENOMEM;
}
i = 1;
if ((retval = krb5_tgtname(context, client, client, &rettree[0]))) {
krb5_xfree(rettree);
return retval;
}
#ifdef CONFIGURABLE_AUTHENTICATION_PATH
links--; /* dont count the null entry on end */
if (cap_code == 0) { /* found a path above */
tmpcrealm.data = client->data;
tmpcrealm.length = client->length;
while( i-1 <= links) {
tmpsrealm.data = cap_nodes[i-1];
/* don't count trailing whitespace from profile_get */
tmpsrealm.length = strcspn(cap_nodes[i-1],"\t ");
if ((retval = krb5_tgtname(context,
&tmpsrealm,
&tmpcrealm,
&rettree[i]))) {
while (i) {
krb5_free_principal(context, rettree[i-1]);
i--;
}
krb5_xfree(rettree);
/* cleanup the cap_nodes from profile_get */
for (i = 0; i<=links; i++) {
krb5_xfree(cap_nodes[i]);
}
krb5_xfree((char *)cap_nodes);
return retval;
}
tmpcrealm.data = tmpsrealm.data;
tmpcrealm.length = tmpsrealm.length;
i++;
}
/* cleanup the cap_nodes from profile_get last one has server */
for (i = 0; i<=links; i++) {
krb5_xfree(cap_nodes[i]);
}
krb5_xfree((char *)cap_nodes);
} else { /* if not cap then use hierarchical method */
#endif
for (prevccp = ccp = client->data;
ccp <= com_cdot;
ccp++) {
if (*ccp != realm_branch_char)
continue;
++ccp; /* advance past dot */
tmpcrealm.data = prevccp;
tmpcrealm.length = client->length -
(prevccp - client->data);
tmpsrealm.data = ccp;
tmpsrealm.length = client->length -
(ccp - client->data);
if ((retval = krb5_tgtname(context, &tmpsrealm, &tmpcrealm,
&rettree[i]))) {
while (i) {
krb5_free_principal(context, rettree[i-1]);
i--;
}
krb5_xfree(rettree);
return retval;
}
prevccp = ccp;
i++;
}
if (nocommon) {
tmpcrealm.data = com_cdot + 1;
tmpcrealm.length = client->length -
(com_cdot + 1 - client->data);
tmpsrealm.data = com_sdot + 1;
tmpsrealm.length = server->length -
(com_sdot + 1 - server->data);
if ((retval = krb5_tgtname(context, &tmpsrealm, &tmpcrealm,
&rettree[i]))) {
while (i) {
krb5_free_principal(context, rettree[i-1]);
i--;
}
krb5_xfree(rettree);
return retval;
}
i++;
}
for (prevscp = com_sdot + 1, scp = com_sdot - 1;
scp > server->data;
scp--) {
if (*scp != realm_branch_char)
continue;
if (scp - 1 < server->data)
break; /* XXX only if . starts realm? */
tmpcrealm.data = prevscp;
tmpcrealm.length = server->length -
(prevscp - server->data);
tmpsrealm.data = scp + 1;
tmpsrealm.length = server->length -
(scp + 1 - server->data);
if ((retval = krb5_tgtname(context, &tmpsrealm, &tmpcrealm,
&rettree[i]))) {
while (i) {
krb5_free_principal(context, rettree[i-1]);
i--;
}
krb5_xfree(rettree);
return retval;
}
prevscp = scp + 1;
i++;
}
if (slen && com_sdot >= server->data) {
/* only necessary if building down tree from ancestor or client */
/* however, we can get here if we have only one component
in the server realm name, hence we make sure we found a component
separator there... */
tmpcrealm.data = prevscp;
tmpcrealm.length = server->length -
(prevscp - server->data);
if ((retval = krb5_tgtname(context, server, &tmpcrealm,
&rettree[i]))) {
while (i) {
krb5_free_principal(context, rettree[i-1]);
i--;
}
krb5_xfree(rettree);
return retval;
}
}
#ifdef CONFIGURABLE_AUTHENTICATION_PATH
}
#endif
*tree = rettree;
return 0;
}
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