+/* $OpenBSD: gss-serv.c,v 1.22 2008/05/08 12:02:23 djm Exp $ */
+
/*
- * Copyright (c) 2001 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 "ssh.h"
-#include "ssh1.h"
-#include "ssh2.h"
+#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 "packet.h"
-#include "compat.h"
-#include <openssl/evp.h>
-#include "cipher.h"
-#include "kex.h"
+#include "key.h"
+#include "hostfile.h"
#include "auth.h"
#include "log.h"
#include "channels.h"
#include "session.h"
-#include "dispatch.h"
+#include "misc.h"
#include "servconf.h"
-#include "compat.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;
-void userauth_reply(Authctxt *authctxt, int authenticated);
-static void gssapi_unsetenv(const char *var);
+static ssh_gssapi_client gssapi_client =
+ { GSS_C_EMPTY_BUFFER, GSS_C_EMPTY_BUFFER,
+ GSS_C_NO_CREDENTIAL, GSS_C_NO_NAME, NULL, {NULL, NULL, NULL}, 0, 0};
-typedef struct ssh_gssapi_cred_cache {
- char *filename;
- char *envvar;
- char *envval;
- void *data;
-} ssh_gssapi_cred_cache;
+ssh_gssapi_mech gssapi_null_mech =
+ { NULL, NULL, {0, NULL}, NULL, NULL, NULL, NULL, NULL};
+
+#ifdef KRB5
+extern ssh_gssapi_mech gssapi_kerberos_mech;
+#endif
+#ifdef GSI
+extern ssh_gssapi_mech gssapi_gsi_mech;
+#endif
-static struct ssh_gssapi_cred_cache gssapi_cred_store = {NULL,NULL,NULL};
-unsigned char ssh1_key_digest[16]; /* used for ssh1 gssapi */
+ssh_gssapi_mech* supported_mechs[]= {
+#ifdef KRB5
+ &gssapi_kerberos_mech,
+#endif
+#ifdef GSI
+ &gssapi_gsi_mech,
+#endif
+ &gssapi_null_mech,
+};
+
+#ifdef GSS_C_GLOBUS_LIMITED_PROXY_FLAG
+static int limited = 0;
+#endif
/*
- * Environment variables pointing to delegated credentials
+ * Acquire credentials for a server running on the current host.
+ * Requires that the context structure contains a valid OID
*/
-static char *delegation_env[] = {
- "X509_USER_PROXY", /* GSSAPI/SSLeay */
- "KRB5CCNAME", /* Krb5 and possibly SSLeay */
- NULL
-};
-#ifdef KRB5
+/* 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;
-#ifdef HEIMDAL
-#include <krb5.h>
-#else
-#include <gssapi_krb5.h>
-#define krb5_get_err_text(context,code) error_message(code)
-#endif
+ if (options.gss_strict_acceptor) {
+ gss_create_empty_oid_set(&status, &oidset);
+ gss_add_oid_set_member(&status, ctx->oid, &oidset);
-static krb5_context krb_context = NULL;
+ if (gethostname(lname, MAXHOSTNAMELEN)) {
+ gss_release_oid_set(&status, &oidset);
+ return (-1);
+ }
-/* Initialise the krb5 library, so we can use it for those bits that
- * GSSAPI won't do */
+ if (GSS_ERROR(ssh_gssapi_import_name(ctx, lname))) {
+ gss_release_oid_set(&status, &oidset);
+ return (ctx->major);
+ }
-int ssh_gssapi_krb5_init() {
- krb5_error_code problem;
-
- if (krb_context !=NULL)
- return 1;
-
- problem = krb5_init_context(&krb_context);
- if (problem) {
- log("Cannot initialize krb5 context");
- return 0;
+ 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;
}
- krb5_init_ets(krb_context);
+ 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));
+}
- return 1;
-}
+/* Unprivileged */
+char *
+ssh_gssapi_server_mechanisms() {
+ gss_OID_set supported;
-/* Check if this user is OK to login. This only works with krb5 - other
- * GSSAPI mechanisms will need their own.
- * Returns true if the user is OK to log in, otherwise returns 0
- */
+ ssh_gssapi_supported_oids(&supported);
+ return (ssh_gssapi_kex_mechs(supported, &ssh_gssapi_server_check_mech,
+ NULL, NULL));
+}
+/* Unprivileged */
int
-ssh_gssapi_krb5_userok(char *name) {
- krb5_principal princ;
- int retval;
+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);
- if (ssh_gssapi_krb5_init() == 0)
- return 0;
-
- if ((retval=krb5_parse_name(krb_context, gssapi_client_name.value,
- &princ))) {
- log("krb5_parse_name(): %.100s",
- krb5_get_err_text(krb_context,retval));
- return 0;
- }
- if (krb5_kuserok(krb_context, princ, name)) {
- retval = 1;
- log("Authorized to %s, krb5 principal %s (krb5_kuserok)",name,
- (char *)gssapi_client_name.value);
- }
- else
- retval = 0;
-
- krb5_free_principal(krb_context, princ);
- return retval;
+ return (res);
}
-
-/* Make sure that this is called _after_ we've setuid to the user */
-
-/* This writes out any forwarded credentials. Its specific to the Kerberos
- * GSSAPI mechanism
- *
- * We assume that our caller has made sure that the user has selected
- * delegated credentials, and that the client_creds structure is correctly
- * populated.
- */
+/* Unprivileged */
void
-ssh_gssapi_krb5_storecreds() {
- krb5_ccache ccache;
- krb5_error_code problem;
- krb5_principal princ;
- char ccname[35];
- static char name[40];
- int tmpfd;
- OM_uint32 maj_status,min_status;
-
-
- if (gssapi_client_creds==NULL) {
- debug("No credentials stored");
+ssh_gssapi_supported_oids(gss_OID_set *oidset)
+{
+ int i = 0;
+ OM_uint32 min_status;
+ int present;
+ gss_OID_set supported;
+
+ gss_create_empty_oid_set(&min_status, oidset);
+
+ /* 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, supported, &present)))
+ present = 0;
+ if (present)
+ gss_add_oid_set_member(&min_status,
+ &supported_mechs[i]->oid, oidset);
+ i++;
}
-
- if (ssh_gssapi_krb5_init() == 0)
- return;
- if (options.gss_use_session_ccache) {
- snprintf(ccname,sizeof(ccname),"/tmp/krb5cc_%d_XXXXXX",geteuid());
-
- if ((tmpfd = mkstemp(ccname))==-1) {
- log("mkstemp(): %.100s", strerror(errno));
- return;
- }
- if (fchmod(tmpfd, S_IRUSR | S_IWUSR) == -1) {
- log("fchmod(): %.100s", strerror(errno));
- close(tmpfd);
- return;
- }
- } else {
- snprintf(ccname,sizeof(ccname),"/tmp/krb5cc_%d",geteuid());
- tmpfd = open(ccname, O_TRUNC | O_CREAT, S_IRUSR | S_IWUSR);
- if (tmpfd == -1) {
- log("open(): %.100s", strerror(errno));
- return;
- }
- }
+ gss_release_oid_set(&min_status, &supported);
+}
- close(tmpfd);
- snprintf(name, sizeof(name), "FILE:%s",ccname);
-
- if ((problem = krb5_cc_resolve(krb_context, name, &ccache))) {
- log("krb5_cc_default(): %.100s",
- krb5_get_err_text(krb_context,problem));
- return;
- }
- if ((problem = krb5_parse_name(krb_context, gssapi_client_name.value,
- &princ))) {
- log("krb5_parse_name(): %.100s",
- krb5_get_err_text(krb_context,problem));
- krb5_cc_destroy(krb_context,ccache);
- return;
- }
-
- if ((problem = krb5_cc_initialize(krb_context, ccache, princ))) {
- log("krb5_cc_initialize(): %.100s",
- krb5_get_err_text(krb_context,problem));
- krb5_free_principal(krb_context,princ);
- krb5_cc_destroy(krb_context,ccache);
- return;
- }
-
- krb5_free_principal(krb_context,princ);
-
- #ifdef HEIMDAL
- if ((problem = krb5_cc_copy_cache(krb_context,
- gssapi_client_creds->ccache,
- ccache))) {
- log("krb5_cc_copy_cache(): %.100s",
- krb5_get_err_text(krb_context,problem));
- krb5_cc_destroy(krb_context,ccache);
- return;
- }
- #else
- if ((maj_status = gss_krb5_copy_ccache(&min_status,
- gssapi_client_creds,
- ccache))) {
- log("gss_krb5_copy_ccache() failed");
- ssh_gssapi_error(maj_status,min_status);
- krb5_cc_destroy(krb_context,ccache);
- return;
- }
- #endif
-
- krb5_cc_close(krb_context,ccache);
+/* Wrapper around accept_sec_context
+ * Requires that the context contains:
+ * oid
+ * credentials (from ssh_gssapi_acquire_cred)
+ */
+/* Privileged */
+OM_uint32
+ssh_gssapi_accept_ctx(Gssctxt *ctx, gss_buffer_desc *recv_tok,
+ gss_buffer_desc *send_tok, OM_uint32 *flags)
+{
+ OM_uint32 status;
+ gss_OID mech;
+ ctx->major = gss_accept_sec_context(&ctx->minor,
+ &ctx->context, ctx->creds, recv_tok,
+ GSS_C_NO_CHANNEL_BINDINGS, &ctx->client, &mech,
+ send_tok, flags, NULL, &ctx->client_creds);
-#ifdef USE_PAM
- do_pam_putenv("KRB5CCNAME",name);
-#endif
+ if (GSS_ERROR(ctx->major))
+ ssh_gssapi_error(ctx);
- gssapi_cred_store.filename=strdup(ccname);
- gssapi_cred_store.envvar="KRB5CCNAME";
- gssapi_cred_store.envval=strdup(name);
+ if (ctx->client_creds)
+ debug("Received some client credentials");
+ else
+ debug("Got no client credentials");
- return;
-}
+ status = ctx->major;
-#endif /* KRB5 */
+ /* Now, if we're complete and we have the right flags, then
+ * we flag the user as also having been authenticated
+ */
-#ifdef GSI
-#include <globus_gss_assist.h>
+ if (((flags == NULL) || ((*flags & GSS_C_MUTUAL_FLAG) &&
+ (*flags & GSS_C_INTEG_FLAG))) && (ctx->major == GSS_S_COMPLETE)) {
+ if (ssh_gssapi_getclient(ctx, &gssapi_client))
+ fatal("Couldn't convert client name");
+#ifdef GSS_C_GLOBUS_LIMITED_PROXY_FLAG
+ if (flags && (*flags & GSS_C_GLOBUS_LIMITED_PROXY_FLAG))
+ limited=1;
+#endif
+ }
-/*
- * Check if this user is OK to login under GSI. User has been authenticated
- * as identity in global 'client_name.value' and is trying to log in as passed
- * username in 'name'.
- *
- * Returns non-zero if user is authorized, 0 otherwise.
- */
-int
-ssh_gssapi_gsi_userok(char *name)
-{
- int authorized = 0;
-
- /* This returns 0 on success */
- authorized = (globus_gss_assist_userok(gssapi_client_name.value,
- name) == 0);
-
- debug("GSI user %s is%s authorized as target user %s",
- (char *) gssapi_client_name.value,
- (authorized ? "" : " not"),
- name);
-
- return authorized;
+ return (status);
}
/*
- * Handle setting up child environment for GSI.
- *
- * Make sure that this is called _after_ we've setuid to the user.
+ * This parses an exported name, extracting the mechanism specific portion
+ * to use for ACL checking. It verifies that the name belongs the mechanism
+ * originally selected.
*/
-void
-ssh_gssapi_gsi_storecreds()
+static OM_uint32
+ssh_gssapi_parse_ename(Gssctxt *ctx, gss_buffer_t ename, gss_buffer_t name)
{
- OM_uint32 major_status;
- OM_uint32 minor_status;
-
-
- if (gssapi_client_creds != NULL)
- {
- char *creds_env = NULL;
-
- /*
- * This is the current hack with the GSI gssapi library to
- * export credentials to disk.
- */
-
- debug("Exporting delegated credentials");
-
- minor_status = 0xdee0; /* Magic value */
- major_status =
- gss_inquire_cred(&minor_status,
- gssapi_client_creds,
- (gss_name_t *) &creds_env,
- NULL,
- NULL,
- NULL);
-
- if ((major_status == GSS_S_COMPLETE) &&
- (minor_status == 0xdee1) &&
- (creds_env != NULL))
- {
- char *value;
-
- /*
- * String is of the form:
- * X509_USER_DELEG_PROXY=filename
- * so we parse out the filename
- * and then set X509_USER_PROXY
- * to point at it.
- */
- value = strchr(creds_env, '=');
-
- if (value != NULL)
- {
- *value = '\0';
- value++;
-#ifdef USE_PAM
- do_pam_putenv("X509_USER_PROXY",value);
+ u_char *tok;
+ OM_uint32 offset;
+ OM_uint32 oidl;
+
+ tok = ename->value;
+
+#ifdef GSI /* GSI gss_export_name() is broken. */
+ if ((ctx->oid->length == gssapi_gsi_mech.oid.length) &&
+ (memcmp(ctx->oid->elements, gssapi_gsi_mech.oid.elements,
+ gssapi_gsi_mech.oid.length) == 0)) {
+ name->length = ename->length;
+ name->value = xmalloc(ename->length+1);
+ memcpy(name->value, ename->value, ename->length);
+ return GSS_S_COMPLETE;
+ }
#endif
- gssapi_cred_store.filename=NULL;
- gssapi_cred_store.envvar="X509_USER_PROXY";
- gssapi_cred_store.envval=strdup(value);
-
- return;
- }
- else
- {
- log("Failed to parse delegated credentials string '%s'",
- creds_env);
- }
+
+ /*
+ * Check that ename is long enough for all of the fixed length
+ * header, and that the initial ID bytes are correct
+ */
+
+ if (ename->length < 6 || memcmp(tok, "\x04\x01", 2) != 0)
+ return GSS_S_FAILURE;
+
+ /*
+ * Extract the OID, and check it. Here GSSAPI breaks with tradition
+ * and does use the OID type and length bytes. To confuse things
+ * there are two lengths - the first including these, and the
+ * second without.
+ */
+
+ oidl = get_u16(tok+2); /* length including next two bytes */
+ oidl = oidl-2; /* turn it into the _real_ length of the variable OID */
+
+ /*
+ * Check the BER encoding for correct type and length, that the
+ * string is long enough and that the OID matches that in our context
+ */
+ if (tok[4] != 0x06 || tok[5] != oidl ||
+ ename->length < oidl+6 ||
+ !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_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);
+ ((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 */
+
+/* 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;
+ }
+
+ /* 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);
}
- else
- {
- log("Failed to export delegated credentials (error %ld)",
- major_status);
+
+ 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;
+
+ while (supported_mechs[i]->name != NULL) {
+ if (supported_mechs[i]->oid.length == ctx->oid->length &&
+ (memcmp(supported_mechs[i]->oid.elements,
+ ctx->oid->elements, ctx->oid->length) == 0))
+ client->mech = supported_mechs[i];
+ i++;
+ }
+
+ if (client->mech == NULL)
+ return GSS_S_FAILURE;
-#endif /* GSI */
+ /* 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);
+ }
+
+ if ((ctx->major = gss_export_name(&ctx->minor, ctx->client,
+ &ename))) {
+ ssh_gssapi_error(ctx);
+ return (ctx->major);
+ }
+
+ if ((ctx->major = ssh_gssapi_parse_ename(ctx,&ename,
+ &client->exportedname))) {
+ 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);
+}
+
+/* As user - called on fatal/exit */
void
-ssh_gssapi_cleanup_creds(void *ignored)
+ssh_gssapi_cleanup_creds(void)
{
- if (gssapi_cred_store.filename!=NULL) {
+ if (gssapi_client.store.filename != NULL) {
/* Unlink probably isn't sufficient */
- debug("removing gssapi cred file\"%s\"",gssapi_cred_store.filename);
- unlink(gssapi_cred_store.filename);
+ debug("removing gssapi cred file\"%s\"",
+ gssapi_client.store.filename);
+ unlink(gssapi_client.store.filename);
}
}
-void
-ssh_gssapi_storecreds()
+/* As user */
+void
+ssh_gssapi_storecreds(void)
{
- switch (gssapi_client_type) {
-#ifdef KRB5
- case GSS_KERBEROS:
- ssh_gssapi_krb5_storecreds();
- break;
-#endif
-#ifdef GSI
- case GSS_GSI:
- ssh_gssapi_gsi_storecreds();
- break;
-#endif /* GSI */
- case GSS_LAST_ENTRY:
- /* GSSAPI not used in this authentication */
- debug("No GSSAPI credentials stored");
- break;
- default:
- log("ssh_gssapi_do_child: Unknown mechanism");
-
- }
-
- if (options.gss_cleanup_creds) {
- fatal_add_cleanup(ssh_gssapi_cleanup_creds, NULL);
- }
-
+ 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");
}
/* This allows GSSAPI methods to do things to the childs environment based
* on the passed authentication process and credentials.
- *
- * Question: If we didn't use userauth_external for some reason, should we
- * still delegate credentials?
*/
-void
-ssh_gssapi_do_child(char ***envp, u_int *envsizep)
+/* As user */
+void
+ssh_gssapi_do_child(char ***envp, u_int *envsizep)
{
- if (gssapi_cred_store.envvar!=NULL &&
- gssapi_cred_store.envval!=NULL) {
-
- debug("Setting %s to %s", gssapi_cred_store.envvar,
- gssapi_cred_store.envval);
- child_set_env(envp, envsizep, gssapi_cred_store.envvar,
- gssapi_cred_store.envval);
- }
-
- switch(gssapi_client_type) {
-#ifdef KRB5
- case GSS_KERBEROS: break;
-#endif
-#ifdef GSI
- case GSS_GSI: break;
-#endif
- case GSS_LAST_ENTRY:
- debug("No GSSAPI credentials stored");
- break;
- default:
- log("ssh_gssapi_do_child: Unknown 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);
+ child_set_env(envp, envsizep, gssapi_client.store.envvar,
+ gssapi_client.store.envval);
}
}
+/* Privileged */
int
-ssh_gssapi_userok(char *user)
+ssh_gssapi_userok(char *user, struct passwd *pw)
{
- if (gssapi_client_name.length==0 ||
- gssapi_client_name.value==NULL) {
+ OM_uint32 lmin;
+
+ if (gssapi_client.exportedname.length == 0 ||
+ gssapi_client.exportedname.value == NULL) {
debug("No suitable client data");
return 0;
}
- switch (gssapi_client_type) {
-#ifdef KRB5
- case GSS_KERBEROS:
- return(ssh_gssapi_krb5_userok(user));
- break; /* Not reached */
-#endif
-#ifdef GSI
- case GSS_GSI:
- return(ssh_gssapi_gsi_userok(user));
- break; /* Not reached */
-#endif /* GSI */
- case GSS_LAST_ENTRY:
- debug("Client not GSSAPI");
- break;
- default:
- debug("Unknown client authentication type");
+#ifdef GSS_C_GLOBUS_LIMITED_PROXY_FLAG
+ if (limited && options.gsi_allow_limited_proxy != 1) {
+ debug("limited proxy not acceptable for remote login");
+ return 0;
}
- return(0);
-}
-
-int
-userauth_external(Authctxt *authctxt)
-{
- packet_check_eom();
-
- return(ssh_gssapi_userok(authctxt->user));
+#endif
+ if (gssapi_client.mech && gssapi_client.mech->userok)
+ if ((*gssapi_client.mech->userok)(&gssapi_client, user)) {
+ gssapi_client.used = 1;
+ gssapi_client.store.owner = pw;
+ return 1;
+ } else {
+ /* Destroy delegated credentials if userok fails */
+ gss_release_buffer(&lmin, &gssapi_client.displayname);
+ gss_release_buffer(&lmin, &gssapi_client.exportedname);
+ gss_release_cred(&lmin, &gssapi_client.creds);
+ memset(&gssapi_client, 0, sizeof(ssh_gssapi_client));
+ return 0;
+ }
+ else
+ debug("ssh_gssapi_userok: Unknown GSSAPI mechanism");
+ return (0);
}
-void input_gssapi_token(int type, u_int32_t plen, void *ctxt);
-void input_gssapi_exchange_complete(int type, u_int32_t plen, void *ctxt);
+/* ssh_gssapi_checkmic() moved to gss-genr.c so it can be called by
+ kexgss_client(). */
-/* We only support those mechanisms that we know about (ie ones that we know
- * how to check local user kuserok and the like
- */
+/* Priviledged */
int
-userauth_gssapi(Authctxt *authctxt)
+ssh_gssapi_localname(char **user)
{
- gss_OID_desc oid= {0,NULL};
- Gssctxt *ctxt;
- int mechs;
- gss_OID_set supported;
- int present;
- OM_uint32 ms;
- u_int len;
-
- if (!authctxt->valid || authctxt->user == NULL)
- return 0;
-
- if (datafellows & SSH_OLD_GSSAPI) {
- debug("Early drafts of GSSAPI userauth not supported");
- return 0;
+ *user = NULL;
+ if (gssapi_client.displayname.length==0 ||
+ gssapi_client.displayname.value==NULL) {
+ debug("No suitable client data");
+ return(0);;
}
-
- mechs=packet_get_int();
- if (mechs==0) {
- debug("Mechanism negotiation is not supported");
- return 0;
+ if (gssapi_client.mech && gssapi_client.mech->localname) {
+ return((*gssapi_client.mech->localname)(&gssapi_client,user));
+ } else {
+ debug("Unknown client authentication type");
}
+ return(0);
+}
- ssh_gssapi_supported_oids(&supported);
- do {
- if (oid.elements)
- xfree(oid.elements);
- oid.elements = packet_get_string(&len);
- oid.length = len;
- gss_test_oid_set_member(&ms, &oid, supported, &present);
- mechs--;
- } while (mechs>0 && !present);
-
- if (!present) {
- xfree(oid.elements);
- return(0);
- }
-
- ctxt=xmalloc(sizeof(Gssctxt));
- authctxt->methoddata=(void *)ctxt;
-
- ssh_gssapi_build_ctx(ctxt);
- ssh_gssapi_set_oid(ctxt,&oid);
-
- if (ssh_gssapi_acquire_cred(ctxt))
- return 0;
+/* 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
+ */
- /* Send SSH_MSG_USERAUTH_GSSAPI_RESPONSE */
+/* Stuff for PAM */
- if (!compat20)
- packet_start(SSH_SMSG_AUTH_GSSAPI_RESPONSE);
- else
- packet_start(SSH2_MSG_USERAUTH_GSSAPI_RESPONSE);
- packet_put_string(oid.elements,oid.length);
- packet_send();
- packet_write_wait();
- xfree(oid.elements);
-
- if (!compat20)
- dispatch_set(SSH_MSG_AUTH_GSSAPI_TOKEN,
- &input_gssapi_token);
- else
- dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_TOKEN,
- &input_gssapi_token);
- authctxt->postponed = 1;
-
- return 0;
+#ifdef USE_PAM
+static int ssh_gssapi_simple_conv(int n, const struct pam_message **msg,
+ struct pam_response **resp, void *data)
+{
+ return (PAM_CONV_ERR);
}
+#endif
void
-input_gssapi_token(int type, u_int32_t plen, void *ctxt)
-{
- Authctxt *authctxt = ctxt;
- Gssctxt *gssctxt;
- gss_buffer_desc send_tok,recv_tok;
- OM_uint32 maj_status, min_status;
-
- if (authctxt == NULL || authctxt->methoddata == NULL)
- fatal("No authentication or GSSAPI context");
-
- gssctxt=authctxt->methoddata;
-
- recv_tok.value=packet_get_string(&recv_tok.length);
-
- maj_status=ssh_gssapi_accept_ctx(gssctxt, &recv_tok, &send_tok, NULL);
- packet_check_eom();
-
- if (GSS_ERROR(maj_status)) {
- /* Failure <sniff> */
- authctxt->postponed = 0;
- dispatch_set(SSH_MSG_AUTH_GSSAPI_TOKEN, NULL);
- dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_TOKEN, NULL);
- userauth_finish(authctxt, 0, "gssapi");
- }
-
- if (send_tok.length != 0) {
- /* Send a packet back to the client */
- if (!compat20)
- packet_start(SSH_MSG_AUTH_GSSAPI_TOKEN);
- else
- packet_start(SSH2_MSG_USERAUTH_GSSAPI_TOKEN);
- packet_put_string(send_tok.value,send_tok.length);
- packet_send();
- packet_write_wait();
- gss_release_buffer(&min_status, &send_tok);
- }
-
- if (maj_status == GSS_S_COMPLETE) {
- dispatch_set(SSH_MSG_AUTH_GSSAPI_TOKEN, NULL);
- dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_TOKEN,NULL);
- /* ssh1 does not have an extra message here */
- if (!compat20)
- input_gssapi_exchange_complete(0, 0, ctxt);
- else
- dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_EXCHANGE_COMPLETE,
- &input_gssapi_exchange_complete);
- }
-}
+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
-/* This is called when the client thinks we've completed authentication.
- * It should only be enabled in the dispatch handler by the function above,
- * which only enables it once the GSSAPI exchange is complete.
- */
+ if (gssapi_client.store.filename == NULL &&
+ gssapi_client.store.envval == NULL &&
+ gssapi_client.store.envvar == NULL)
+ return;
-void
-input_gssapi_exchange_complete(int type, u_int32_t plen, void *ctxt)
-{
- Authctxt *authctxt = ctxt;
- Gssctxt *gssctxt;
- int authenticated;
-
- if (authctxt == NULL || authctxt->methoddata == NULL)
- fatal("No authentication or GSSAPI context");
-
- gssctxt=authctxt->methoddata;
-
- /* This should never happen, but better safe than sorry. */
- if (gssctxt->status != GSS_S_COMPLETE) {
- packet_disconnect("Context negotiation is not complete");
- }
+ ok = PRIVSEP(ssh_gssapi_update_creds(&gssapi_client.store));
+
+ if (!ok)
+ return;
+
+ debug("Rekeyed credentials stored successfully");
- if (ssh_gssapi_getclient(gssctxt,&gssapi_client_type,
- &gssapi_client_name,
- &gssapi_client_creds)) {
- fatal("Couldn't convert client name");
+ /* 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;
}
-
- authenticated = ssh_gssapi_userok(authctxt->user);
-
- /* ssh1 needs to exchange the hash of the keys */
- if (!compat20) {
- if (authenticated) {
-
- OM_uint32 maj_status, min_status;
- gss_buffer_desc gssbuf,msg_tok;
-
- /* ssh1 uses wrap */
- gssbuf.value=ssh1_key_digest;
- gssbuf.length=sizeof(ssh1_key_digest);
- if ((maj_status=gss_wrap(&min_status,
- gssctxt->context,
- 0,
- GSS_C_QOP_DEFAULT,
- &gssbuf,
- NULL,
- &msg_tok))) {
- ssh_gssapi_error(maj_status,min_status);
- fatal("Couldn't wrap keys");
- }
- packet_start(SSH_SMSG_AUTH_GSSAPI_HASH);
- packet_put_string((char *)msg_tok.value,msg_tok.length);
- packet_send();
- packet_write_wait();
- gss_release_buffer(&min_status,&msg_tok);
- } else {
- packet_start(SSH_MSG_AUTH_GSSAPI_ABORT);
- packet_send();
- packet_write_wait();
- }
+
+ 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);
- authctxt->postponed = 0;
- dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_TOKEN, NULL);
- dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_EXCHANGE_COMPLETE, NULL);
- userauth_finish(authctxt, authenticated, "gssapi");
-}
+ xasprintf(&envstr, "%s=%s", gssapi_client.store.envvar,
+ gssapi_client.store.envval);
-/*
- * Clean our environment on startup. This means removing any environment
- * strings that might inadvertantly been in root's environment and
- * could cause serious security problems if we think we set them.
- */
-void
-ssh_gssapi_clean_env(void)
-{
- char *envstr;
- int envstr_index;
-
-
- for (envstr_index = 0;
- (envstr = delegation_env[envstr_index]) != NULL;
- envstr_index++) {
-
- if (getenv(envstr)) {
- debug("Clearing environment variable %s", envstr);
- gssapi_unsetenv(envstr);
- }
- }
+ ret = pam_putenv(pamh, envstr);
+ if (!ret)
+ pam_setcred(pamh, PAM_REINITIALIZE_CRED);
+ pam_end(pamh, PAM_SUCCESS);
+#endif
}
-/*
- * Wrapper around unsetenv.
- */
-static void
-gssapi_unsetenv(const char *var)
-{
-#ifdef HAVE_UNSETENV
- unsetenv(var);
-
-#else /* !HAVE_UNSETENV */
- extern char **environ;
- char **p1 = environ; /* New array list */
- char **p2 = environ; /* Current array list */
- int len = strlen(var);
-
- /*
- * Walk through current environ array (p2) copying each pointer
- * to new environ array (p1) unless the pointer is to the item
- * we want to delete. Copy happens in place.
- */
- while (*p2) {
- if ((strncmp(*p2, var, len) == 0) &&
- ((*p2)[len] == '=')) {
- /*
- * *p2 points at item to be deleted, just skip over it
- */
- p2++;
- } else {
- /*
- * *p2 points at item we want to save, so copy it
- */
- *p1 = *p2;
- p1++;
- p2++;
- }
- }
+int
+ssh_gssapi_update_creds(ssh_gssapi_ccache *store) {
+ int ok = 0;
- /* And make sure new array is NULL terminated */
- *p1 = NULL;
-#endif /* HAVE_UNSETENV */
+ /* 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;
+}
+
+void
+ssh_gssapi_get_client_info(char **userdn, char **mech) {
+ *userdn = gssapi_client.displayname.value;
+ *mech = gssapi_client.mech->name;
}
-#endif /* GSSAPI */
+#endif
andersk / gssapi-openssh.git / blobdiff