--- /dev/null
+/* $OpenBSD: gss-genr.c,v 1.20 2009/06/22 05:39:28 dtucker Exp $ */
+
+/*
+ * Copyright (c) 2001-2007 Simon Wilkinson. 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.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR `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 AUTHOR 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 "includes.h"
+
+#ifdef GSSAPI
+
+#include <sys/types.h>
+#include <sys/param.h>
+
+#include <stdarg.h>
+#include <string.h>
+#include <unistd.h>
+
+#include "xmalloc.h"
+#include "buffer.h"
+#include "log.h"
+#include "ssh2.h"
+
+#include "ssh-gss.h"
+
+extern u_char *session_id2;
+extern u_int session_id2_len;
+
+/* Check that the OID in a data stream matches that in the context */
+int
+ssh_gssapi_check_oid(Gssctxt *ctx, void *data, size_t len)
+{
+ return (ctx != NULL && ctx->oid != GSS_C_NO_OID &&
+ ctx->oid->length == len &&
+ memcmp(ctx->oid->elements, data, len) == 0);
+}
+
+/* Set the contexts OID from a data stream */
+void
+ssh_gssapi_set_oid_data(Gssctxt *ctx, void *data, size_t len)
+{
+ if (ctx->oid != GSS_C_NO_OID) {
+ xfree(ctx->oid->elements);
+ xfree(ctx->oid);
+ }
+ ctx->oid = xmalloc(sizeof(gss_OID_desc));
+ ctx->oid->length = len;
+ ctx->oid->elements = xmalloc(len);
+ memcpy(ctx->oid->elements, data, len);
+}
+
+/* Set the contexts OID */
+void
+ssh_gssapi_set_oid(Gssctxt *ctx, gss_OID oid)
+{
+ ssh_gssapi_set_oid_data(ctx, oid->elements, oid->length);
+}
+
+/* All this effort to report an error ... */
+void
+ssh_gssapi_error(Gssctxt *ctxt)
+{
+ char *s;
+
+ s = ssh_gssapi_last_error(ctxt, NULL, NULL);
+ debug("%s", s);
+ xfree(s);
+}
+
+char *
+ssh_gssapi_last_error(Gssctxt *ctxt, OM_uint32 *major_status,
+ OM_uint32 *minor_status)
+{
+ OM_uint32 lmin;
+ gss_buffer_desc msg = GSS_C_EMPTY_BUFFER;
+ OM_uint32 ctx;
+ Buffer b;
+ char *ret;
+
+ buffer_init(&b);
+
+ if (major_status != NULL)
+ *major_status = ctxt->major;
+ if (minor_status != NULL)
+ *minor_status = ctxt->minor;
+
+ ctx = 0;
+ /* The GSSAPI error */
+ do {
+ gss_display_status(&lmin, ctxt->major,
+ GSS_C_GSS_CODE, ctxt->oid, &ctx, &msg);
+
+ buffer_append(&b, msg.value, msg.length);
+ buffer_put_char(&b, '\n');
+
+ gss_release_buffer(&lmin, &msg);
+ } while (ctx != 0);
+
+ /* The mechanism specific error */
+ do {
+ gss_display_status(&lmin, ctxt->minor,
+ GSS_C_MECH_CODE, ctxt->oid, &ctx, &msg);
+
+ buffer_append(&b, msg.value, msg.length);
+ buffer_put_char(&b, '\n');
+
+ gss_release_buffer(&lmin, &msg);
+ } while (ctx != 0);
+
+ buffer_put_char(&b, '\0');
+ ret = xmalloc(buffer_len(&b));
+ buffer_get(&b, ret, buffer_len(&b));
+ buffer_free(&b);
+ return (ret);
+}
+
+/*
+ * Initialise our GSSAPI context. We use this opaque structure to contain all
+ * of the data which both the client and server need to persist across
+ * {accept,init}_sec_context calls, so that when we do it from the userauth
+ * stuff life is a little easier
+ */
+void
+ssh_gssapi_build_ctx(Gssctxt **ctx)
+{
+ *ctx = xcalloc(1, sizeof (Gssctxt));
+ (*ctx)->context = GSS_C_NO_CONTEXT;
+ (*ctx)->name = GSS_C_NO_NAME;
+ (*ctx)->oid = GSS_C_NO_OID;
+ (*ctx)->creds = GSS_C_NO_CREDENTIAL;
+ (*ctx)->client = GSS_C_NO_NAME;
+ (*ctx)->client_creds = GSS_C_NO_CREDENTIAL;
+}
+
+/* Delete our context, providing it has been built correctly */
+void
+ssh_gssapi_delete_ctx(Gssctxt **ctx)
+{
+ OM_uint32 ms;
+
+ if ((*ctx) == NULL)
+ return;
+ if ((*ctx)->context != GSS_C_NO_CONTEXT)
+ gss_delete_sec_context(&ms, &(*ctx)->context, GSS_C_NO_BUFFER);
+ if ((*ctx)->name != GSS_C_NO_NAME)
+ gss_release_name(&ms, &(*ctx)->name);
+ if ((*ctx)->oid != GSS_C_NO_OID) {
+ xfree((*ctx)->oid->elements);
+ xfree((*ctx)->oid);
+ (*ctx)->oid = GSS_C_NO_OID;
+ }
+ if ((*ctx)->creds != GSS_C_NO_CREDENTIAL)
+ gss_release_cred(&ms, &(*ctx)->creds);
+ if ((*ctx)->client != GSS_C_NO_NAME)
+ gss_release_name(&ms, &(*ctx)->client);
+ if ((*ctx)->client_creds != GSS_C_NO_CREDENTIAL)
+ gss_release_cred(&ms, &(*ctx)->client_creds);
+
+ xfree(*ctx);
+ *ctx = NULL;
+}
+
+/*
+ * Wrapper to init_sec_context
+ * Requires that the context contains:
+ * oid
+ * server name (from ssh_gssapi_import_name)
+ */
+OM_uint32
+ssh_gssapi_init_ctx(Gssctxt *ctx, int deleg_creds, gss_buffer_desc *recv_tok,
+ gss_buffer_desc* send_tok, OM_uint32 *flags)
+{
+ int deleg_flag = 0;
+
+ if (deleg_creds) {
+ deleg_flag = GSS_C_DELEG_FLAG;
+ debug("Delegating credentials");
+ }
+
+ ctx->major = gss_init_sec_context(&ctx->minor,
+ GSS_C_NO_CREDENTIAL, &ctx->context, ctx->name, ctx->oid,
+ GSS_C_MUTUAL_FLAG | GSS_C_INTEG_FLAG | deleg_flag,
+ 0, NULL, recv_tok, NULL, send_tok, flags, NULL);
+
+ if (GSS_ERROR(ctx->major))
+ ssh_gssapi_error(ctx);
+
+ return (ctx->major);
+}
+
+/* Create a service name for the given host */
+OM_uint32
+ssh_gssapi_import_name(Gssctxt *ctx, const char *host)
+{
+ gss_buffer_desc gssbuf;
+ char *val;
+
+ xasprintf(&val, "host@%s", host);
+ gssbuf.value = val;
+ gssbuf.length = strlen(gssbuf.value);
+
+ if ((ctx->major = gss_import_name(&ctx->minor,
+ &gssbuf, GSS_C_NT_HOSTBASED_SERVICE, &ctx->name)))
+ ssh_gssapi_error(ctx);
+
+ xfree(gssbuf.value);
+ return (ctx->major);
+}
+
+OM_uint32
+ssh_gssapi_sign(Gssctxt *ctx, gss_buffer_t buffer, gss_buffer_t hash)
+{
+ if ((ctx->major = gss_get_mic(&ctx->minor, ctx->context,
+ GSS_C_QOP_DEFAULT, buffer, hash)))
+ ssh_gssapi_error(ctx);
+
+ return (ctx->major);
+}
+
+void
+ssh_gssapi_buildmic(Buffer *b, const char *user, const char *service,
+ const char *context)
+{
+ buffer_init(b);
+ buffer_put_string(b, session_id2, session_id2_len);
+ buffer_put_char(b, SSH2_MSG_USERAUTH_REQUEST);
+ buffer_put_cstring(b, user);
+ buffer_put_cstring(b, service);
+ buffer_put_cstring(b, context);
+}
+
+int
+ssh_gssapi_check_mechanism(Gssctxt **ctx, gss_OID oid, const char *host)
+{
+ gss_buffer_desc token = GSS_C_EMPTY_BUFFER;
+ OM_uint32 major, minor;
+ gss_OID_desc spnego_oid = {6, (void *)"\x2B\x06\x01\x05\x05\x02"};
+
+ /* RFC 4462 says we MUST NOT do SPNEGO */
+ if (oid->length == spnego_oid.length &&
+ (memcmp(oid->elements, spnego_oid.elements, oid->length) == 0))
+ return 0; /* false */
+
+ ssh_gssapi_build_ctx(ctx);
+ ssh_gssapi_set_oid(*ctx, oid);
+ major = ssh_gssapi_import_name(*ctx, host);
+ if (!GSS_ERROR(major)) {
+ major = ssh_gssapi_init_ctx(*ctx, 0, GSS_C_NO_BUFFER, &token,
+ NULL);
+ gss_release_buffer(&minor, &token);
+ if ((*ctx)->context != GSS_C_NO_CONTEXT)
+ gss_delete_sec_context(&minor, &(*ctx)->context,
+ GSS_C_NO_BUFFER);
+ }
+
+ if (GSS_ERROR(major))
+ ssh_gssapi_delete_ctx(ctx);
+
+ return (!GSS_ERROR(major));
+}
+
+#endif /* GSSAPI */
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