-/* $OpenBSD: gss-serv.c,v 1.8 2005/08/30 22:08:05 djm Exp $ */
+/* $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
#ifdef GSSAPI
+#include <sys/types.h>
+#include <sys/param.h>
+
+#include <stdarg.h>
+#include <string.h>
+#include <unistd.h>
+
+#include "openbsd-compat/sys-queue.h"
+#include "xmalloc.h"
#include "buffer.h"
-#include "bufaux.h"
-#include "compat.h"
-#include <openssl/evp.h>
-#include "kex.h"
+#include "key.h"
+#include "hostfile.h"
#include "auth.h"
#include "log.h"
#include "channels.h"
#include "session.h"
+#include "misc.h"
#include "servconf.h"
-#include "monitor_wrap.h"
-#include "xmalloc.h"
-#include "getput.h"
+#include "uidswap.h"
+#include "xmalloc.h"
#include "ssh-gss.h"
+#include "monitor_wrap.h"
extern ServerOptions options;
-extern u_char *session_id2;
-extern int session_id2_len;
+extern Authctxt *the_authctxt;
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;
static int limited = 0;
#endif
-/* Unpriviledged */
+/*
+ * Acquire credentials for a server running on the current host.
+ * Requires that the context structure contains a valid OID
+ */
+
+/* Returns a GSSAPI error code */
+/* Privileged (called from ssh_gssapi_server_ctx) */
+static OM_uint32
+ssh_gssapi_acquire_cred(Gssctxt *ctx)
+{
+ OM_uint32 status;
+ char lname[MAXHOSTNAMELEN];
+ gss_OID_set 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 (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);
+
+ gss_release_oid_set(&status, &oidset);
+ return (ctx->major);
+ } else {
+ ctx->name = GSS_C_NO_NAME;
+ ctx->creds = GSS_C_NO_CREDENTIAL;
+ }
+ return GSS_S_COMPLETE;
+}
+
+/* Privileged */
+OM_uint32
+ssh_gssapi_server_ctx(Gssctxt **ctx, gss_OID oid)
+{
+ if (*ctx)
+ ssh_gssapi_delete_ctx(ctx);
+ ssh_gssapi_build_ctx(ctx);
+ ssh_gssapi_set_oid(*ctx, oid);
+ return (ssh_gssapi_acquire_cred(*ctx));
+}
+
+/* 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);
- /* Ask priviledged process what mechanisms it supports. */
- PRIVSEP(gss_indicate_mechs(&min_status, &supported));
+
+ /* Ask privileged process what mechanisms it supports. */
+ if (GSS_ERROR(PRIVSEP(gss_indicate_mechs(&min_status, &supported))))
+ return;
while (supported_mechs[i]->name != NULL) {
if (GSS_ERROR(gss_test_oid_set_member(&min_status,
&supported_mechs[i]->oid, oidset);
i++;
}
+
+ gss_release_oid_set(&min_status, &supported);
}
* oid
* credentials (from ssh_gssapi_acquire_cred)
*/
-/* Priviledged */
+/* Privileged */
OM_uint32
ssh_gssapi_accept_ctx(Gssctxt *ctx, gss_buffer_desc *recv_tok,
gss_buffer_desc *send_tok, OM_uint32 *flags)
OM_uint32 offset;
OM_uint32 oidl;
- tok=ename->value;
+ tok = ename->value;
#ifdef GSI /* GSI gss_export_name() is broken. */
if ((ctx->oid->length == gssapi_gsi_mech.oid.length) &&
* header, and that the initial ID bytes are correct
*/
- if (ename->length<6 || memcmp(tok,"\x04\x01", 2)!=0)
+ if (ename->length < 6 || memcmp(tok, "\x04\x01", 2) != 0)
return GSS_S_FAILURE;
/*
* second without.
*/
- oidl = GET_16BIT(tok+2); /* length including next two bytes */
+ oidl = get_u16(tok+2); /* length including next two bytes */
oidl = oidl-2; /* turn it into the _real_ length of the variable OID */
/*
*/
if (tok[4] != 0x06 || tok[5] != oidl ||
ename->length < oidl+6 ||
- !ssh_gssapi_check_oid(ctx,tok+6,oidl))
+ !ssh_gssapi_check_oid(ctx, tok+6, oidl))
return GSS_S_FAILURE;
offset = oidl+6;
if (ename->length < offset+4)
return GSS_S_FAILURE;
- name->length = GET_32BIT(tok+offset);
+ name->length = get_u32(tok+offset);
offset += 4;
if (ename->length < offset+name->length)
return GSS_S_FAILURE;
name->value = xmalloc(name->length+1);
- memcpy(name->value,tok+offset,name->length);
+ memcpy(name->value, tok+offset, name->length);
((char *)name->value)[name->length] = 0;
return GSS_S_COMPLETE;
/* Extract the client details from a given context. This can only reliably
* be called once for a context */
-/* Priviledged (called from accept_secure_ctx) */
+/* Privileged (called from accept_secure_ctx) */
OM_uint32
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;
+ }
- gss_buffer_desc ename;
+ /* Call gss_inquire_cred rather than gss_inquire_cred_by_mech
+ because GSI doesn't support the latter. -jbasney */
+
+ if ((ctx->major = gss_inquire_cred(&ctx->minor,
+ ctx->client_creds, &new_name,
+ NULL, NULL, NULL))) {
+ ssh_gssapi_error(ctx);
+ return (ctx->major);
+ }
+
+ ctx->major = gss_compare_name(&ctx->minor, client->name,
+ new_name, &equal);
+
+ 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;
+ /* Call gss_inquire_cred rather than gss_inquire_cred_by_mech
+ because GSI doesn't support the latter. -jbasney */
+
+ if (ctx->client_creds &&
+ (ctx->major = gss_inquire_cred(&ctx->minor,
+ ctx->client_creds, &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;
+
+ /* needed for globus_gss_assist_map_and_authorize() */
+ client->context = ctx->context;
+
return (ctx->major);
}
{
if (gssapi_client.store.filename != NULL) {
/* Unlink probably isn't sufficient */
- debug("removing gssapi cred file\"%s\"", gssapi_client.store.filename);
+ debug("removing gssapi cred file\"%s\"",
+ gssapi_client.store.filename);
unlink(gssapi_client.store.filename);
}
}
ssh_gssapi_storecreds(void)
{
if (gssapi_client.mech && gssapi_client.mech->storecreds) {
+ if (options.gss_creds_path) {
+ gssapi_client.store.filename =
+ expand_authorized_keys(options.gss_creds_path,
+ the_authctxt->pw);
+ }
(*gssapi_client.mech->storecreds)(&gssapi_client);
} else
debug("ssh_gssapi_storecreds: Not a GSSAPI mechanism");
if (gssapi_client.store.envvar != NULL &&
gssapi_client.store.envval != NULL) {
-
debug("Setting %s to %s", gssapi_client.store.envvar,
- gssapi_client.store.envval);
+ gssapi_client.store.envval);
child_set_env(envp, envsizep, gssapi_client.store.envvar,
gssapi_client.store.envval);
}
}
-/* Priviledged */
+/* Privileged */
int
-ssh_gssapi_userok(char *user)
+ssh_gssapi_userok(char *user, struct passwd *pw)
{
OM_uint32 lmin;
return 0;
}
#ifdef GSS_C_GLOBUS_LIMITED_PROXY_FLAG
- if (limited) {
+ if (limited && options.gsi_allow_limited_proxy != 1) {
debug("limited proxy not acceptable for remote login");
return 0;
}
#endif
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);
}
-/* Return a list of the gss-group1-sha1-x mechanisms supported by this
- * program.
- *
- * We only support the mechanisms that we've indicated in the list above,
- * but we check that they're supported by the GSSAPI mechanism on the
- * machine. We also check, before including them in the list, that
- * we have the necesary information in order to carry out the key exchange
- * (that is, that the user has credentials, the server's creds are accessible,
- * etc)
- *
- * The way that this is done is fairly nasty, as we do a lot of work that
- * is then thrown away. This should possibly be implemented with a cache
- * that stores the results (in an expanded Gssctxt structure), which are
- * then used by the first calls if that key exchange mechanism is chosen.
- */
-
-/* Unpriviledged */
-char *
-ssh_gssapi_server_mechanisms() {
- gss_OID_set supported;
- Gssctxt *ctx = NULL;
- OM_uint32 maj_status, min_status;
- Buffer buf;
- int i = 0;
- int first = 0;
- int present;
- char * mechs;
-
- ssh_gssapi_supported_oids(&supported);
-
- buffer_init(&buf);
-
- while(supported_mechs[i]->name != NULL) {
- if ((maj_status=gss_test_oid_set_member(&min_status,
- &supported_mechs[i]->oid,
- supported,
- &present))) {
- present=0;
- }
-
- if (present) {
- if (!GSS_ERROR(PRIVSEP(ssh_gssapi_server_ctx(&ctx,
- &supported_mechs[i]->oid)))) {
- /* Append gss_group1_sha1_x to our list */
- if (first++!=0)
- buffer_put_char(&buf,',');
- buffer_append(&buf, KEX_GSS_SHA1,
- sizeof(KEX_GSS_SHA1)-1);
- buffer_append(&buf,
- supported_mechs[i]->enc_name,
- strlen(supported_mechs[i]->enc_name));
- debug("GSSAPI mechanism %s (%s%s) supported",
- supported_mechs[i]->name, KEX_GSS_SHA1,
- supported_mechs[i]->enc_name);
- } else {
- debug("no credentials for GSSAPI mechanism %s",
- supported_mechs[i]->name);
- }
- } else {
- debug("GSSAPI mechanism %s not supported",
- supported_mechs[i]->name);
- }
- ssh_gssapi_delete_ctx(&ctx);
- i++;
- }
-
- buffer_put_char(&buf,'\0');
-
- mechs=xmalloc(buffer_len(&buf));
- buffer_get(&buf,mechs,buffer_len(&buf));
- buffer_free(&buf);
- if (strlen(mechs)==0) {
- options.gss_authentication = 0; /* no mechs. skip gss auth. */
- return(NULL);
- } else {
- return(mechs);
- }
-}
-
-/* Return the OID that corresponds to the given context name */
-
-/* Unpriviledged */
-gss_OID
-ssh_gssapi_server_id_kex(char *name) {
- int i=0;
-
- if (strncmp(name, KEX_GSS_SHA1, sizeof(KEX_GSS_SHA1)-1) !=0) {
- return(NULL);
- }
-
- name+=sizeof(KEX_GSS_SHA1)-1; /* Move to the start of the MIME string */
-
- while (supported_mechs[i]->name!=NULL &&
- strcmp(name,supported_mechs[i]->enc_name)!=0) {
- i++;
- }
-
- if (supported_mechs[i]->name==NULL)
- return (NULL);
-
- debug("using GSSAPI mechanism %s (%s%s)", supported_mechs[i]->name,
- KEX_GSS_SHA1, supported_mechs[i]->enc_name);
-
- return &supported_mechs[i]->oid;
-}
+/* ssh_gssapi_checkmic() moved to gss-genr.c so it can be called by
+ kexgss_client(). */
/* Priviledged */
int
return(0);
}
-/* Priviledged */
-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;
+#ifdef USE_PAM
+ int ret;
+ pam_handle_t *pamh = NULL;
+ struct pam_conv pamconv = {ssh_gssapi_simple_conv, NULL};
+ char *envstr;
+ char **p;char **pw;
+#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;
+
+ /* Put ssh pam stack env variables in this new pam stack env
+ * Using pam-pkinit, KRB5CCNAME is set during do_pam_session
+ * this addition enables pam-pkinit to access KRB5CCNAME if used
+ * in sshd-rekey stack too
+ */
+ pw = p = fetch_pam_environment();
+ while ( *pw != NULL ) {
+ pam_putenv(pamh,*pw);
+ pw++;
+ }
+ free_pam_environment(p);
+
+ 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
andersk / gssapi-openssh.git / blobdiff