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/* $OpenBSD: gss-serv.c,v 1.5 2003/11/17 11:06:07 markus Exp $ */
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* Copyright (c) 2001-2003 Simon Wilkinson. All rights reserved.
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR `AS IS'' AND ANY EXPRESS OR
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* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
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* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
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* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
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* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
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* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
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* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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#include "monitor_wrap.h"
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extern ServerOptions options;
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static ssh_gssapi_client gssapi_client =
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{ GSS_C_EMPTY_BUFFER, GSS_C_EMPTY_BUFFER,
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GSS_C_NO_CREDENTIAL, NULL, {NULL, NULL, NULL}};
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ssh_gssapi_mech gssapi_null_mech =
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{ NULL, NULL, {0, NULL}, NULL, NULL, NULL, NULL};
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extern ssh_gssapi_mech gssapi_kerberos_mech;
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ssh_gssapi_mech* supported_mechs[]= {
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&gssapi_kerberos_mech,
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ssh_gssapi_supported_oids(gss_OID_set *oidset)
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gss_OID_set supported;
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gss_create_empty_oid_set(&min_status, oidset);
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gss_indicate_mechs(&min_status, &supported);
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while (supported_mechs[i]->name != NULL) {
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if (GSS_ERROR(gss_test_oid_set_member(&min_status,
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&supported_mechs[i]->oid, supported, &present)))
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gss_add_oid_set_member(&min_status,
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&supported_mechs[i]->oid, oidset);
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/* Wrapper around accept_sec_context
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* Requires that the context contains:
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* credentials (from ssh_gssapi_acquire_cred)
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ssh_gssapi_accept_ctx(Gssctxt *ctx, gss_buffer_desc *recv_tok,
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gss_buffer_desc *send_tok, OM_uint32 *flags)
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ctx->major = gss_accept_sec_context(&ctx->minor,
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&ctx->context, ctx->creds, recv_tok,
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GSS_C_NO_CHANNEL_BINDINGS, &ctx->client, &mech,
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send_tok, flags, NULL, &ctx->client_creds);
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if (GSS_ERROR(ctx->major))
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ssh_gssapi_error(ctx);
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if (ctx->client_creds)
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debug("Received some client credentials");
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debug("Got no client credentials");
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/* Now, if we're complete and we have the right flags, then
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* we flag the user as also having been authenticated
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if (((flags == NULL) || ((*flags & GSS_C_MUTUAL_FLAG) &&
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(*flags & GSS_C_INTEG_FLAG))) && (ctx->major == GSS_S_COMPLETE)) {
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if (ssh_gssapi_getclient(ctx, &gssapi_client))
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fatal("Couldn't convert client name");
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* This parses an exported name, extracting the mechanism specific portion
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* to use for ACL checking. It verifies that the name belongs the mechanism
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* originally selected.
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ssh_gssapi_parse_ename(Gssctxt *ctx, gss_buffer_t ename, gss_buffer_t name)
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* Check that ename is long enough for all of the fixed length
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* header, and that the initial ID bytes are correct
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if (ename->length<6 || memcmp(tok,"\x04\x01", 2)!=0)
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return GSS_S_FAILURE;
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* Extract the OID, and check it. Here GSSAPI breaks with tradition
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* and does use the OID type and length bytes. To confuse things
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* there are two lengths - the first including these, and the
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oidl = GET_16BIT(tok+2); /* length including next two bytes */
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oidl = oidl-2; /* turn it into the _real_ length of the variable OID */
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* Check the BER encoding for correct type and length, that the
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* string is long enough and that the OID matches that in our context
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if (tok[4] != 0x06 || tok[5] != oidl ||
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ename->length < oidl+6 ||
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!ssh_gssapi_check_oid(ctx,tok+6,oidl))
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return GSS_S_FAILURE;
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if (ename->length < offset+4)
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return GSS_S_FAILURE;
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name->length = GET_32BIT(tok+offset);
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if (ename->length < offset+name->length)
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return GSS_S_FAILURE;
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name->value = xmalloc(name->length+1);
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memcpy(name->value,tok+offset,name->length);
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((char *)name->value)[name->length] = 0;
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return GSS_S_COMPLETE;
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/* Extract the client details from a given context. This can only reliably
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* be called once for a context */
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/* Priviledged (called from accept_secure_ctx) */
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ssh_gssapi_getclient(Gssctxt *ctx, ssh_gssapi_client *client)
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gss_buffer_desc ename;
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while (supported_mechs[i]->name != NULL) {
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if (supported_mechs[i]->oid.length == ctx->oid->length &&
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(memcmp(supported_mechs[i]->oid.elements,
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ctx->oid->elements, ctx->oid->length) == 0))
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client->mech = supported_mechs[i];
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if (client->mech == NULL)
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return GSS_S_FAILURE;
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if ((ctx->major = gss_display_name(&ctx->minor, ctx->client,
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&client->displayname, NULL))) {
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ssh_gssapi_error(ctx);
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if ((ctx->major = gss_export_name(&ctx->minor, ctx->client,
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ssh_gssapi_error(ctx);
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if ((ctx->major = ssh_gssapi_parse_ename(ctx,&ename,
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&client->exportedname))) {
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/* We can't copy this structure, so we just move the pointer to it */
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client->creds = ctx->client_creds;
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ctx->client_creds = GSS_C_NO_CREDENTIAL;
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/* As user - called on fatal/exit */
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ssh_gssapi_cleanup_creds(void)
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if (gssapi_client.store.filename != NULL) {
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/* Unlink probably isn't sufficient */
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debug("removing gssapi cred file\"%s\"", gssapi_client.store.filename);
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unlink(gssapi_client.store.filename);
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ssh_gssapi_storecreds(void)
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if (gssapi_client.mech && gssapi_client.mech->storecreds) {
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(*gssapi_client.mech->storecreds)(&gssapi_client);
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debug("ssh_gssapi_storecreds: Not a GSSAPI mechanism");
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/* This allows GSSAPI methods to do things to the childs environment based
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* on the passed authentication process and credentials.
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ssh_gssapi_do_child(char ***envp, u_int *envsizep)
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if (gssapi_client.store.envvar != NULL &&
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gssapi_client.store.envval != NULL) {
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debug("Setting %s to %s", gssapi_client.store.envvar,
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gssapi_client.store.envval);
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child_set_env(envp, envsizep, gssapi_client.store.envvar,
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gssapi_client.store.envval);
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ssh_gssapi_userok(char *user)
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if (gssapi_client.exportedname.length == 0 ||
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gssapi_client.exportedname.value == NULL) {
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debug("No suitable client data");
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if (gssapi_client.mech && gssapi_client.mech->userok)
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return ((*gssapi_client.mech->userok)(&gssapi_client, user));
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debug("ssh_gssapi_userok: Unknown GSSAPI mechanism");
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ssh_gssapi_checkmic(Gssctxt *ctx, gss_buffer_t gssbuf, gss_buffer_t gssmic)
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ctx->major = gss_verify_mic(&ctx->minor, ctx->context,
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gssbuf, gssmic, NULL);
added
removed
gss-serv.c
