/* $OpenBSD: gss-serv.c,v 1.22 2008/05/08 12:02:23 djm Exp $ */
/*
- * Copyright (c) 2001-2003 Simon Wilkinson. All rights reserved.
+ * Copyright (c) 2001-2009 Simon Wilkinson. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
#include "channels.h"
#include "session.h"
#include "misc.h"
+#include "servconf.h"
+#include "uidswap.h"
#include "ssh-gss.h"
+#include "monitor_wrap.h"
+
+extern ServerOptions options;
static ssh_gssapi_client gssapi_client =
{ GSS_C_EMPTY_BUFFER, GSS_C_EMPTY_BUFFER,
- GSS_C_NO_CREDENTIAL, NULL, {NULL, NULL, NULL}};
+ GSS_C_NO_CREDENTIAL, GSS_C_NO_NAME, NULL, {NULL, NULL, NULL}, 0, 0};
ssh_gssapi_mech gssapi_null_mech =
- { NULL, NULL, {0, NULL}, NULL, NULL, NULL, NULL};
+ { NULL, NULL, {0, NULL}, NULL, NULL, NULL, NULL, NULL};
#ifdef KRB5
extern ssh_gssapi_mech gssapi_kerberos_mech;
char lname[MAXHOSTNAMELEN];
gss_OID_set oidset;
- gss_create_empty_oid_set(&status, &oidset);
- gss_add_oid_set_member(&status, ctx->oid, &oidset);
+ if (options.gss_strict_acceptor) {
+ gss_create_empty_oid_set(&status, &oidset);
+ gss_add_oid_set_member(&status, ctx->oid, &oidset);
- if (gethostname(lname, MAXHOSTNAMELEN)) {
- gss_release_oid_set(&status, &oidset);
- return (-1);
- }
+ if (gethostname(lname, MAXHOSTNAMELEN)) {
+ gss_release_oid_set(&status, &oidset);
+ return (-1);
+ }
+
+ if (GSS_ERROR(ssh_gssapi_import_name(ctx, lname))) {
+ gss_release_oid_set(&status, &oidset);
+ return (ctx->major);
+ }
+
+ if ((ctx->major = gss_acquire_cred(&ctx->minor,
+ ctx->name, 0, oidset, GSS_C_ACCEPT, &ctx->creds,
+ NULL, NULL)))
+ ssh_gssapi_error(ctx);
- if (GSS_ERROR(ssh_gssapi_import_name(ctx, lname))) {
gss_release_oid_set(&status, &oidset);
return (ctx->major);
+ } else {
+ ctx->name = GSS_C_NO_NAME;
+ ctx->creds = GSS_C_NO_CREDENTIAL;
}
-
- if ((ctx->major = gss_acquire_cred(&ctx->minor,
- ctx->name, 0, oidset, GSS_C_ACCEPT, &ctx->creds, NULL, NULL)))
- ssh_gssapi_error(ctx);
-
- gss_release_oid_set(&status, &oidset);
- return (ctx->major);
+ return GSS_S_COMPLETE;
}
/* Privileged */
}
/* Unprivileged */
+char *
+ssh_gssapi_server_mechanisms() {
+ gss_OID_set supported;
+
+ ssh_gssapi_supported_oids(&supported);
+ return (ssh_gssapi_kex_mechs(supported, &ssh_gssapi_server_check_mech,
+ NULL, NULL));
+}
+
+/* Unprivileged */
+int
+ssh_gssapi_server_check_mech(Gssctxt **dum, gss_OID oid, const char *data,
+ const char *dummy) {
+ Gssctxt *ctx = NULL;
+ int res;
+
+ res = !GSS_ERROR(PRIVSEP(ssh_gssapi_server_ctx(&ctx, oid)));
+ ssh_gssapi_delete_ctx(&ctx);
+
+ return (res);
+}
+
+/* Unprivileged */
void
ssh_gssapi_supported_oids(gss_OID_set *oidset)
{
gss_OID_set supported;
gss_create_empty_oid_set(&min_status, oidset);
- gss_indicate_mechs(&min_status, &supported);
+
+ if (GSS_ERROR(gss_indicate_mechs(&min_status, &supported)))
+ return;
while (supported_mechs[i]->name != NULL) {
if (GSS_ERROR(gss_test_oid_set_member(&min_status,
ssh_gssapi_getclient(Gssctxt *ctx, ssh_gssapi_client *client)
{
int i = 0;
+ int equal = 0;
+ gss_name_t new_name = GSS_C_NO_NAME;
+ gss_buffer_desc ename = GSS_C_EMPTY_BUFFER;
+
+ if (options.gss_store_rekey && client->used && ctx->client_creds) {
+ if (client->mech->oid.length != ctx->oid->length ||
+ (memcmp(client->mech->oid.elements,
+ ctx->oid->elements, ctx->oid->length) !=0)) {
+ debug("Rekeyed credentials have different mechanism");
+ return GSS_S_COMPLETE;
+ }
+
+ if ((ctx->major = gss_inquire_cred_by_mech(&ctx->minor,
+ ctx->client_creds, ctx->oid, &new_name,
+ NULL, NULL, NULL))) {
+ ssh_gssapi_error(ctx);
+ return (ctx->major);
+ }
+
+ ctx->major = gss_compare_name(&ctx->minor, client->name,
+ new_name, &equal);
- gss_buffer_desc ename;
+ if (GSS_ERROR(ctx->major)) {
+ ssh_gssapi_error(ctx);
+ return (ctx->major);
+ }
+
+ if (!equal) {
+ debug("Rekeyed credentials have different name");
+ return GSS_S_COMPLETE;
+ }
+
+ debug("Marking rekeyed credentials for export");
+
+ gss_release_name(&ctx->minor, &client->name);
+ gss_release_cred(&ctx->minor, &client->creds);
+ client->name = new_name;
+ client->creds = ctx->client_creds;
+ ctx->client_creds = GSS_C_NO_CREDENTIAL;
+ client->updated = 1;
+ return GSS_S_COMPLETE;
+ }
client->mech = NULL;
if (client->mech == NULL)
return GSS_S_FAILURE;
+ if (ctx->client_creds &&
+ (ctx->major = gss_inquire_cred_by_mech(&ctx->minor,
+ ctx->client_creds, ctx->oid, &client->name, NULL, NULL, NULL))) {
+ ssh_gssapi_error(ctx);
+ return (ctx->major);
+ }
+
if ((ctx->major = gss_display_name(&ctx->minor, ctx->client,
&client->displayname, NULL))) {
ssh_gssapi_error(ctx);
return (ctx->major);
}
+ gss_release_buffer(&ctx->minor, &ename);
+
/* We can't copy this structure, so we just move the pointer to it */
client->creds = ctx->client_creds;
ctx->client_creds = GSS_C_NO_CREDENTIAL;
/* Privileged */
int
-ssh_gssapi_userok(char *user)
+ssh_gssapi_userok(char *user, struct passwd *pw)
{
OM_uint32 lmin;
return 0;
}
if (gssapi_client.mech && gssapi_client.mech->userok)
- if ((*gssapi_client.mech->userok)(&gssapi_client, user))
+ if ((*gssapi_client.mech->userok)(&gssapi_client, user)) {
+ gssapi_client.used = 1;
+ gssapi_client.store.owner = pw;
return 1;
- else {
+ } else {
/* Destroy delegated credentials if userok fails */
gss_release_buffer(&lmin, &gssapi_client.displayname);
gss_release_buffer(&lmin, &gssapi_client.exportedname);
return (0);
}
-/* Privileged */
-OM_uint32
-ssh_gssapi_checkmic(Gssctxt *ctx, gss_buffer_t gssbuf, gss_buffer_t gssmic)
+/* These bits are only used for rekeying. The unpriviledged child is running
+ * as the user, the monitor is root.
+ *
+ * In the child, we want to :
+ * *) Ask the monitor to store our credentials into the store we specify
+ * *) If it succeeds, maybe do a PAM update
+ */
+
+/* Stuff for PAM */
+
+#ifdef USE_PAM
+static int ssh_gssapi_simple_conv(int n, const struct pam_message **msg,
+ struct pam_response **resp, void *data)
{
- ctx->major = gss_verify_mic(&ctx->minor, ctx->context,
- gssbuf, gssmic, NULL);
+ return (PAM_CONV_ERR);
+}
+#endif
- return (ctx->major);
+void
+ssh_gssapi_rekey_creds() {
+ int ok;
+ int ret;
+#ifdef USE_PAM
+ pam_handle_t *pamh = NULL;
+ struct pam_conv pamconv = {ssh_gssapi_simple_conv, NULL};
+ char *envstr;
+#endif
+
+ if (gssapi_client.store.filename == NULL &&
+ gssapi_client.store.envval == NULL &&
+ gssapi_client.store.envvar == NULL)
+ return;
+
+ ok = PRIVSEP(ssh_gssapi_update_creds(&gssapi_client.store));
+
+ if (!ok)
+ return;
+
+ debug("Rekeyed credentials stored successfully");
+
+ /* Actually managing to play with the ssh pam stack from here will
+ * be next to impossible. In any case, we may want different options
+ * for rekeying. So, use our own :)
+ */
+#ifdef USE_PAM
+ if (!use_privsep) {
+ debug("Not even going to try and do PAM with privsep disabled");
+ return;
+ }
+
+ ret = pam_start("sshd-rekey", gssapi_client.store.owner->pw_name,
+ &pamconv, &pamh);
+ if (ret)
+ return;
+
+ xasprintf(&envstr, "%s=%s", gssapi_client.store.envvar,
+ gssapi_client.store.envval);
+
+ ret = pam_putenv(pamh, envstr);
+ if (!ret)
+ pam_setcred(pamh, PAM_REINITIALIZE_CRED);
+ pam_end(pamh, PAM_SUCCESS);
+#endif
+}
+
+int
+ssh_gssapi_update_creds(ssh_gssapi_ccache *store) {
+ int ok = 0;
+
+ /* Check we've got credentials to store */
+ if (!gssapi_client.updated)
+ return 0;
+
+ gssapi_client.updated = 0;
+
+ temporarily_use_uid(gssapi_client.store.owner);
+ if (gssapi_client.mech && gssapi_client.mech->updatecreds)
+ ok = (*gssapi_client.mech->updatecreds)(store, &gssapi_client);
+ else
+ debug("No update function for this mechanism");
+
+ restore_uid();
+
+ return ok;
}
#endif
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