summaryrefslogtreecommitdiffstats
path: root/third_party/heimdal/lib/krb5/transited.c
diff options
context:
space:
mode:
Diffstat (limited to 'third_party/heimdal/lib/krb5/transited.c')
-rw-r--r--third_party/heimdal/lib/krb5/transited.c699
1 files changed, 699 insertions, 0 deletions
diff --git a/third_party/heimdal/lib/krb5/transited.c b/third_party/heimdal/lib/krb5/transited.c
new file mode 100644
index 0000000..484fd39
--- /dev/null
+++ b/third_party/heimdal/lib/krb5/transited.c
@@ -0,0 +1,699 @@
+/*
+ * Copyright (c) 1997 - 2001, 2003 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"
+
+/* this is an attempt at one of the most horrible `compression'
+ schemes that has ever been invented; it's so amazingly brain-dead
+ that words can not describe it, and all this just to save a few
+ silly bytes */
+
+struct tr_realm {
+ char *realm;
+ unsigned leading_space:1;
+ unsigned leading_slash:1;
+ unsigned trailing_dot:1;
+ struct tr_realm *next;
+};
+
+static void
+free_realms(struct tr_realm *r)
+{
+ struct tr_realm *p;
+ while(r){
+ p = r;
+ r = r->next;
+ free(p->realm);
+ free(p);
+ }
+}
+
+static int
+make_path(krb5_context context, struct tr_realm *r,
+ const char *from, const char *to)
+{
+ struct tr_realm *tmp;
+ const char *p;
+
+ if(strlen(from) < strlen(to)){
+ const char *str;
+ str = from;
+ from = to;
+ to = str;
+ }
+
+ if(strcmp(from + strlen(from) - strlen(to), to) == 0){
+ p = from;
+ while(1){
+ p = strchr(p, '.');
+ if(p == NULL) {
+ krb5_clear_error_message (context);
+ return KRB5KDC_ERR_POLICY;
+ }
+ p++;
+ if(strcmp(p, to) == 0)
+ break;
+ tmp = calloc(1, sizeof(*tmp));
+ if(tmp == NULL)
+ return krb5_enomem(context);
+ tmp->next = r->next;
+ r->next = tmp;
+ tmp->realm = strdup(p);
+ if(tmp->realm == NULL){
+ r->next = tmp->next;
+ free(tmp);
+ return krb5_enomem(context);
+ }
+ }
+ }else if(strncmp(from, to, strlen(to)) == 0){
+ p = from + strlen(from);
+ while(1){
+ while(p >= from && *p != '/') p--;
+ if(p == from)
+ return KRB5KDC_ERR_POLICY;
+
+ if(strncmp(to, from, p - from) == 0)
+ break;
+ tmp = calloc(1, sizeof(*tmp));
+ if(tmp == NULL)
+ return krb5_enomem(context);
+ tmp->next = r->next;
+ r->next = tmp;
+ tmp->realm = malloc(p - from + 1);
+ if(tmp->realm == NULL){
+ r->next = tmp->next;
+ free(tmp);
+ return krb5_enomem(context);
+ }
+ memcpy(tmp->realm, from, p - from);
+ tmp->realm[p - from] = '\0';
+ p--;
+ }
+ } else {
+ krb5_clear_error_message (context);
+ return KRB5KDC_ERR_POLICY;
+ }
+
+ return 0;
+}
+
+static int
+make_paths(krb5_context context,
+ struct tr_realm *realms, const char *client_realm,
+ const char *server_realm)
+{
+ struct tr_realm *r;
+ int ret;
+ const char *prev_realm = client_realm;
+ const char *next_realm = NULL;
+ for(r = realms; r; r = r->next){
+ /* it *might* be that you can have more than one empty
+ component in a row, at least that's how I interpret the
+ "," exception in 1510 */
+ if(r->realm[0] == '\0'){
+ while(r->next && r->next->realm[0] == '\0')
+ r = r->next;
+ if(r->next)
+ next_realm = r->next->realm;
+ else
+ next_realm = server_realm;
+ ret = make_path(context, r, prev_realm, next_realm);
+ if(ret){
+ free_realms(realms);
+ return ret;
+ }
+ }
+ prev_realm = r->realm;
+ }
+ return 0;
+}
+
+static int
+expand_realms(krb5_context context,
+ struct tr_realm *realms, const char *client_realm)
+{
+ struct tr_realm *r;
+ const char *prev_realm = NULL;
+ for(r = realms; r; r = r->next){
+ if(r->trailing_dot){
+ char *tmp;
+ size_t len;
+
+ if(prev_realm == NULL)
+ prev_realm = client_realm;
+
+ len = strlen(r->realm) + strlen(prev_realm) + 1;
+
+ tmp = realloc(r->realm, len);
+ if(tmp == NULL){
+ free_realms(realms);
+ return krb5_enomem(context);
+ }
+ r->realm = tmp;
+ strlcat(r->realm, prev_realm, len);
+ }else if(r->leading_slash && !r->leading_space && prev_realm){
+ /* yet another exception: if you use x500-names, the
+ leading realm doesn't have to be "quoted" with a space */
+ char *tmp;
+ size_t len = strlen(r->realm) + strlen(prev_realm) + 1;
+
+ tmp = malloc(len);
+ if(tmp == NULL){
+ free_realms(realms);
+ return krb5_enomem(context);
+ }
+ strlcpy(tmp, prev_realm, len);
+ strlcat(tmp, r->realm, len);
+ free(r->realm);
+ r->realm = tmp;
+ }
+ prev_realm = r->realm;
+ }
+ return 0;
+}
+
+static struct tr_realm *
+make_realm(char *realm)
+{
+ struct tr_realm *r;
+ char *p, *q;
+ int quote = 0;
+ r = calloc(1, sizeof(*r));
+ if(r == NULL){
+ free(realm);
+ return NULL;
+ }
+ r->realm = realm;
+ for(p = q = r->realm; *p; p++){
+ if(p == r->realm && *p == ' '){
+ r->leading_space = 1;
+ continue;
+ }
+ if(q == r->realm && *p == '/')
+ r->leading_slash = 1;
+ if(quote){
+ *q++ = *p;
+ quote = 0;
+ continue;
+ }
+ if(*p == '\\'){
+ quote = 1;
+ continue;
+ }
+ if(p[0] == '.' && p[1] == '\0')
+ r->trailing_dot = 1;
+ *q++ = *p;
+ }
+ *q = '\0';
+ return r;
+}
+
+static struct tr_realm*
+append_realm(struct tr_realm *head, struct tr_realm *r)
+{
+ struct tr_realm *p;
+ if(head == NULL){
+ r->next = NULL;
+ return r;
+ }
+ p = head;
+ while(p->next) p = p->next;
+ p->next = r;
+ return head;
+}
+
+static int
+decode_realms(krb5_context context,
+ const char *tr, int length, struct tr_realm **realms)
+{
+ struct tr_realm *r = NULL;
+
+ char *tmp;
+ int quote = 0;
+ const char *start = tr;
+ int i;
+
+ for(i = 0; i < length; i++){
+ if(quote){
+ quote = 0;
+ continue;
+ }
+ if(tr[i] == '\\'){
+ quote = 1;
+ continue;
+ }
+ if(tr[i] == ','){
+ tmp = malloc(tr + i - start + 1);
+ if(tmp == NULL) {
+ free_realms(*realms);
+ *realms = NULL;
+ return krb5_enomem(context);
+ }
+ memcpy(tmp, start, tr + i - start);
+ tmp[tr + i - start] = '\0';
+ r = make_realm(tmp);
+ if(r == NULL){
+ free_realms(*realms);
+ *realms = NULL;
+ return krb5_enomem(context);
+ }
+ *realms = append_realm(*realms, r);
+ start = tr + i + 1;
+ }
+ }
+ tmp = malloc(tr + i - start + 1);
+ if(tmp == NULL){
+ free_realms(*realms);
+ *realms = NULL;
+ return krb5_enomem(context);
+ }
+ memcpy(tmp, start, tr + i - start);
+ tmp[tr + i - start] = '\0';
+ r = make_realm(tmp);
+ if(r == NULL){
+ free_realms(*realms);
+ *realms = NULL;
+ return krb5_enomem(context);
+ }
+ *realms = append_realm(*realms, r);
+
+ return 0;
+}
+
+
+KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
+krb5_domain_x500_decode(krb5_context context,
+ krb5_data tr, char ***realms, unsigned int *num_realms,
+ const char *client_realm, const char *server_realm)
+{
+ struct tr_realm *r = NULL;
+ struct tr_realm *p, **q;
+ int ret;
+
+ if(tr.length == 0) {
+ *realms = NULL;
+ *num_realms = 0;
+ return 0;
+ }
+
+ /* split string in components */
+ ret = decode_realms(context, tr.data, tr.length, &r);
+ if(ret)
+ return ret;
+
+ /* apply prefix rule */
+ ret = expand_realms(context, r, client_realm);
+ if(ret)
+ return ret;
+
+ ret = make_paths(context, r, client_realm, server_realm);
+ if(ret)
+ return ret;
+
+ /* remove empty components and count realms */
+ *num_realms = 0;
+ for(q = &r; *q; ){
+ if((*q)->realm[0] == '\0'){
+ p = *q;
+ *q = (*q)->next;
+ free(p->realm);
+ free(p);
+ }else{
+ q = &(*q)->next;
+ (*num_realms)++;
+ }
+ }
+ if (*num_realms + 1 > UINT_MAX/sizeof(**realms))
+ return ERANGE;
+
+ {
+ char **R;
+ R = malloc((*num_realms + 1) * sizeof(*R));
+ *realms = R;
+ while(r){
+ *R++ = r->realm;
+ p = r->next;
+ free(r);
+ r = p;
+ }
+ if (*realms == NULL)
+ return krb5_enomem(context);
+ }
+ return 0;
+}
+
+KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
+krb5_domain_x500_encode(char **realms, unsigned int num_realms,
+ krb5_data *encoding)
+{
+ char *s = NULL;
+ int len = 0;
+ unsigned int i;
+ krb5_data_zero(encoding);
+ if (num_realms == 0)
+ return 0;
+ for(i = 0; i < num_realms; i++){
+ len += strlen(realms[i]);
+ if(realms[i][0] == '/')
+ len++;
+ }
+ len += num_realms - 1;
+ s = malloc(len + 1);
+ if (s == NULL)
+ return ENOMEM;
+ *s = '\0';
+ for(i = 0; i < num_realms; i++){
+ if(i)
+ strlcat(s, ",", len + 1);
+ if(realms[i][0] == '/')
+ strlcat(s, " ", len + 1);
+ strlcat(s, realms[i], len + 1);
+ }
+ encoding->data = s;
+ encoding->length = strlen(s);
+ return 0;
+}
+
+KRB5_LIB_FUNCTION void KRB5_LIB_CALL
+_krb5_free_capath(krb5_context context, char **capath)
+{
+ char **s;
+
+ for (s = capath; s && *s; ++s)
+ free(*s);
+ free(capath);
+}
+
+struct hier_iter {
+ const char *local_realm;
+ const char *server_realm;
+ const char *lr; /* Pointer into tail of local realm */
+ const char *sr; /* Pointer into tail of server realm */
+ size_t llen; /* Length of local_realm */
+ size_t slen; /* Length of server_realm */
+ size_t len; /* Length of common suffix */
+ size_t num; /* Path element count */
+};
+
+/*
+ * Step up from local_realm to common suffix, or else down to server_realm.
+ */
+static const char *
+hier_next(struct hier_iter *state)
+{
+ const char *lr = state->lr;
+ const char *sr = state->sr;
+ const char *lsuffix = state->local_realm + state->llen - state->len;
+ const char *server_realm = state->server_realm;
+
+ if (lr != NULL) {
+ while (lr < lsuffix)
+ if (*lr++ == '.')
+ return state->lr = lr;
+ state->lr = NULL;
+ }
+ if (sr != NULL) {
+ while (--sr >= server_realm)
+ if (sr == server_realm || sr[-1] == '.')
+ return state->sr = sr;
+ state->sr = NULL;
+ }
+ return NULL;
+}
+
+static void
+hier_init(struct hier_iter *state, const char *local_realm, const char *server_realm)
+{
+ size_t llen;
+ size_t slen;
+ size_t len = 0;
+ const char *lr;
+ const char *sr;
+
+ state->local_realm = local_realm;
+ state->server_realm = server_realm;
+ state->llen = llen = strlen(local_realm);
+ state->slen = slen = strlen(server_realm);
+ state->len = 0;
+ state->num = 0;
+
+ if (slen == 0 || llen == 0)
+ return;
+
+ /* Find first difference from the back */
+ for (lr = local_realm + llen, sr = server_realm + slen;
+ lr != local_realm && sr != server_realm;
+ --lr, --sr) {
+ if (lr[-1] != sr[-1])
+ break;
+ if (lr[-1] == '.')
+ len = llen - (lr - local_realm);
+ }
+
+ /* Nothing in common? */
+ if (*lr == '\0')
+ return;
+
+ /* Everything in common? */
+ if (llen == slen && lr == local_realm)
+ return;
+
+ /* Is one realm is a suffix of the other? */
+ if ((llen < slen && lr == local_realm && sr[-1] == '.') ||
+ (llen > slen && sr == server_realm && lr[-1] == '.'))
+ len = llen - (lr - local_realm);
+
+ state->len = len;
+ /* `lr` starts at local realm and walks up the tree to common suffix */
+ state->lr = local_realm;
+ /* `sr` starts at common suffix in server realm and walks down the tree */
+ state->sr = server_realm + slen - len;
+
+ /* Count elements and reset */
+ while (hier_next(state) != NULL)
+ ++state->num;
+ state->lr = local_realm;
+ state->sr = server_realm + slen - len;
+}
+
+/*
+ * Find a referral path from client_realm to server_realm via local_realm.
+ * Either via [capaths] or hierarchicaly.
+ */
+KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
+_krb5_find_capath(krb5_context context,
+ const char *client_realm,
+ const char *local_realm,
+ const char *server_realm,
+ krb5_boolean use_hierarchical,
+ char ***rpath,
+ size_t *npath)
+{
+ char **confpath;
+ char **capath;
+ struct hier_iter hier_state;
+ char **rp;
+ const char *r;
+
+ *rpath = NULL;
+ *npath = 0;
+
+ confpath = krb5_config_get_strings(context, NULL, "capaths",
+ client_realm, server_realm, NULL);
+ if (confpath == NULL)
+ confpath = krb5_config_get_strings(context, NULL, "capaths",
+ local_realm, server_realm, NULL);
+ /*
+ * With a [capaths] setting from the client to the server we look for our
+ * own realm in the list. If our own realm is not present, we return the
+ * full list. Otherwise, we return our realm's successors, or possibly
+ * NULL. Ignoring a [capaths] settings risks loops plus would violate
+ * explicit policy and the principle of least surpise.
+ */
+ if (confpath != NULL) {
+ char **start = confpath;
+ size_t i;
+ size_t n;
+
+ for (rp = start; *rp; rp++)
+ if (strcmp(*rp, local_realm) == 0)
+ start = rp+1;
+ n = rp - start;
+
+ if (n == 0) {
+ krb5_config_free_strings(confpath);
+ return 0;
+ }
+
+ capath = calloc(n + 1, sizeof(*capath));
+ if (capath == NULL) {
+ krb5_config_free_strings(confpath);
+ return krb5_enomem(context);
+ }
+
+ for (i = 0, rp = start; *rp; rp++) {
+ if ((capath[i++] = strdup(*rp)) == NULL) {
+ _krb5_free_capath(context, capath);
+ krb5_config_free_strings(confpath);
+ return krb5_enomem(context);
+ }
+ }
+ krb5_config_free_strings(confpath);
+ capath[i] = NULL;
+ *rpath = capath;
+ *npath = n;
+ return 0;
+ }
+
+ /* The use_hierarchical flag makes hierarchical path lookup unconditional */
+ if (! use_hierarchical &&
+ ! krb5_config_get_bool_default(context, NULL, TRUE, "libdefaults",
+ "allow_hierarchical_capaths", NULL))
+ return 0;
+
+ /*
+ * When validating transit paths, local_realm == client_realm. Otherwise,
+ * with hierarchical referrals, they may differ, and we may be building a
+ * path forward from our own realm!
+ */
+ hier_init(&hier_state, local_realm, server_realm);
+ if (hier_state.num == 0)
+ return 0;
+
+ rp = capath = calloc(hier_state.num + 1, sizeof(*capath));
+ if (capath == NULL)
+ return krb5_enomem(context);
+ while ((r = hier_next(&hier_state)) != NULL) {
+ if ((*rp++ = strdup(r)) == NULL) {
+ _krb5_free_capath(context, capath);
+ return krb5_enomem(context);
+ }
+ }
+
+ *rp = NULL;
+ *rpath = capath;
+ *npath = hier_state.num;
+ return 0;
+}
+
+KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
+krb5_check_transited(krb5_context context,
+ krb5_const_realm client_realm,
+ krb5_const_realm server_realm,
+ krb5_realm *realms,
+ unsigned int num_realms,
+ int *bad_realm)
+{
+ krb5_error_code ret = 0;
+ char **capath = NULL;
+ size_t num_capath = 0;
+ size_t i = 0;
+ size_t j = 0;
+
+ /* In transit checks hierarchical capaths are optional */
+ ret = _krb5_find_capath(context, client_realm, client_realm, server_realm,
+ FALSE, &capath, &num_capath);
+ if (ret)
+ return ret;
+
+ for (i = 0; i < num_realms; i++) {
+ for (j = 0; j < num_capath && capath[j]; ++j) {
+ /* `capath[j]' can't be NULL, but compilers be dumb */
+ if (strcmp(realms[i], capath[j]) == 0)
+ break;
+ }
+ if (j == num_capath || !capath[j]) {
+ _krb5_free_capath(context, capath);
+ krb5_set_error_message (context, KRB5KRB_AP_ERR_ILL_CR_TKT,
+ N_("no transit allowed "
+ "through realm %s from %s to %s", ""),
+ realms[i], client_realm, server_realm);
+ if (bad_realm)
+ *bad_realm = i;
+ return KRB5KRB_AP_ERR_ILL_CR_TKT;
+ }
+ }
+
+ _krb5_free_capath(context, capath);
+ return 0;
+}
+
+KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
+krb5_check_transited_realms(krb5_context context,
+ const char *const *realms,
+ unsigned int num_realms,
+ int *bad_realm)
+{
+ size_t i;
+ int ret = 0;
+ char **bad_realms = krb5_config_get_strings(context, NULL,
+ "libdefaults",
+ "transited_realms_reject",
+ NULL);
+ if(bad_realms == NULL)
+ return 0;
+
+ for(i = 0; i < num_realms; i++) {
+ char **p;
+ for(p = bad_realms; *p; p++)
+ if(strcmp(*p, realms[i]) == 0) {
+ ret = KRB5KRB_AP_ERR_ILL_CR_TKT;
+ krb5_set_error_message (context, ret,
+ N_("no transit allowed "
+ "through realm %s", ""),
+ *p);
+ if(bad_realm)
+ *bad_realm = i;
+ break;
+ }
+ }
+ krb5_config_free_strings(bad_realms);
+ return ret;
+}
+
+#if 0
+int
+main(int argc, char **argv)
+{
+ krb5_data x;
+ char **r;
+ int num, i;
+ x.data = argv[1];
+ x.length = strlen(x.data);
+ if(domain_expand(x, &r, &num, argv[2], argv[3]))
+ exit(1);
+ for(i = 0; i < num; i++)
+ printf("%s\n", r[i]);
+ return 0;
+}
+#endif
generated by cgit v1.2.3 (git 2.39.1) at 2024-06-16 10:07:50 +0000