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land lustre part of b_hd_sec on HEAD.
[fs/lustre-release.git] / lustre / sec / gss / gss_krb5_unseal.c
diff --git a/lustre/sec/gss/gss_krb5_unseal.c b/lustre/sec/gss/gss_krb5_unseal.c
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+/* -*- mode: c; c-basic-offset: 8; indent-tabs-mode: nil; -*-
+ * vim:expandtab:shiftwidth=8:tabstop=8:
+ *
+ * Modifications for Lustre
+ * Copyright 2004, Cluster File Systems, Inc.
+ * All rights reserved
+ * Author: Eric Mei <ericm@clusterfs.com>
+ */
+
+/*
+ *  linux/net/sunrpc/gss_krb5_unseal.c
+ *
+ *  Adapted from MIT Kerberos 5-1.2.1 lib/gssapi/krb5/k5unseal.c
+ *
+ *  Copyright (c) 2000 The Regents of the University of Michigan.
+ *  All rights reserved.
+ *
+ *  Andy Adamson   <andros@umich.edu>
+ */
+
+/*
+ * Copyright 1993 by OpenVision Technologies, Inc.
+ *
+ * Permission to use, copy, modify, distribute, and sell this software
+ * and its documentation for any purpose is hereby granted without fee,
+ * provided that the above copyright notice appears in all copies and
+ * that both that copyright notice and this permission notice appear in
+ * supporting documentation, and that the name of OpenVision not be used
+ * in advertising or publicity pertaining to distribution of the software
+ * without specific, written prior permission. OpenVision makes no
+ * representations about the suitability of this software for any
+ * purpose.  It is provided "as is" without express or implied warranty.
+ *
+ * OPENVISION DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
+ * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
+ * EVENT SHALL OPENVISION BE LIABLE FOR ANY SPECIAL, INDIRECT OR
+ * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF
+ * USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR
+ * OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
+ * PERFORMANCE OF THIS SOFTWARE.
+ */
+
+/*
+ * Copyright (C) 1998 by the FundsXpress, INC.
+ *
+ * All rights reserved.
+ *
+ * Export of this software from the United States of America may require
+ * a specific license from the United States Government.  It is the
+ * responsibility of any person or organization contemplating export to
+ * obtain such a license before exporting.
+ *
+ * WITHIN THAT CONSTRAINT, permission to use, copy, modify, and
+ * distribute this software and its documentation for any purpose and
+ * without fee is hereby granted, provided that the above copyright
+ * notice appear in all copies and that both that copyright notice and
+ * this permission notice appear in supporting documentation, and that
+ * the name of FundsXpress. not be used in advertising or publicity pertaining
+ * to distribution of the software without specific, written prior
+ * permission.  FundsXpress makes no representations about the suitability of
+ * this software for any purpose.  It is provided "as is" without express
+ * or implied warranty.
+ *
+ * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
+ * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
+ */
+
+#ifndef EXPORT_SYMTAB
+# define EXPORT_SYMTAB
+#endif
+#define DEBUG_SUBSYSTEM S_SEC
+#ifdef __KERNEL__
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/crypto.h>
+#else
+#include <liblustre.h>
+#include "../kcrypto/libcrypto.h"
+#endif
+
+#include <libcfs/kp30.h>
+#include <linux/obd.h>
+#include <linux/obd_class.h>
+#include <linux/obd_support.h>
+#include <linux/lustre_idl.h>
+#include <linux/lustre_net.h>
+#include <linux/lustre_import.h>
+#include <linux/lustre_sec.h>
+
+#include "gss_err.h"
+#include "gss_internal.h"
+#include "gss_api.h"
+#include "gss_krb5.h"
+
+
+/* read_token is a mic token, and message_buffer is the data that the mic was
+ * supposedly taken over. */
+
+__u32
+krb5_read_token(struct krb5_ctx *ctx,
+                rawobj_t *read_token,
+                rawobj_t *message_buffer,
+                int *qop_state)
+{
+        int                     signalg;
+        int                     sealalg;
+        __s32                   checksum_type;
+        rawobj_t                md5cksum = {.len = 0, .data = NULL};
+        __s32                   now;
+        int                     direction;
+        __s32                   seqnum;
+        unsigned char          *ptr = (unsigned char *)read_token->data;
+        int                     bodysize;
+        __u32                   ret = GSS_S_DEFECTIVE_TOKEN;
+        ENTRY;
+
+        if (g_verify_token_header(&ctx->mech_used, &bodysize, &ptr,
+                                  read_token->len))
+                goto out;
+
+        if ((*ptr++ != ((KG_TOK_MIC_MSG>>8)&0xff)) ||
+            (*ptr++ != ( KG_TOK_MIC_MSG    &0xff))   )
+                goto out;
+
+        /* XXX sanity-check bodysize?? */
+
+        /* get the sign and seal algorithms */
+
+        signalg = ptr[0] + (ptr[1] << 8);
+        sealalg = ptr[2] + (ptr[3] << 8);
+
+        /* Sanity checks */
+
+        if ((ptr[4] != 0xff) || (ptr[5] != 0xff))
+                goto out;
+
+        if (sealalg != 0xffff)
+                goto out;
+
+        /* there are several mappings of seal algorithms to sign algorithms,
+           but few enough that we can try them all. */
+
+        if ((ctx->sealalg == SEAL_ALG_NONE && signalg > 1) ||
+            (ctx->sealalg == SEAL_ALG_1 && signalg != SGN_ALG_3) ||
+            (ctx->sealalg == SEAL_ALG_DES3KD &&
+             signalg != SGN_ALG_HMAC_SHA1_DES3_KD))
+                goto out;
+
+        /* compute the checksum of the message */
+
+        /* initialize the the cksum */
+        switch (signalg) {
+        case SGN_ALG_DES_MAC_MD5:
+                checksum_type = CKSUMTYPE_RSA_MD5;
+                break;
+        default:
+                ret = GSS_S_DEFECTIVE_TOKEN;
+                goto out;
+        }
+
+        switch (signalg) {
+        case SGN_ALG_DES_MAC_MD5:
+                ret = make_checksum(checksum_type, ptr - 2, 8,
+                                    message_buffer, &md5cksum);
+                if (ret)
+                        goto out;
+
+                ret = krb5_encrypt(ctx->seq, NULL, md5cksum.data,
+                                   md5cksum.data, 16);
+                if (ret)
+                        goto out;
+
+                if (memcmp(md5cksum.data + 8, ptr + 14, 8)) {
+                        ret = GSS_S_BAD_SIG;
+                        goto out;
+                }
+                break;
+        default:
+                ret = GSS_S_DEFECTIVE_TOKEN;
+                goto out;
+        }
+
+        /* it got through unscathed.  Make sure the context is unexpired */
+
+        if (qop_state)
+                *qop_state = GSS_C_QOP_DEFAULT;
+
+        now = get_seconds();
+
+        ret = GSS_S_CONTEXT_EXPIRED;
+        if (now > ctx->endtime)
+                goto out;
+
+        /* do sequencing checks */
+
+        ret = GSS_S_BAD_SIG;
+        if ((ret = krb5_get_seq_num(ctx->seq, ptr + 14, ptr + 6, &direction,
+                                    &seqnum)))
+                goto out;
+
+        if ((ctx->initiate && direction != 0xff) ||
+            (!ctx->initiate && direction != 0))
+                goto out;
+
+        ret = GSS_S_COMPLETE;
+out:
+        if (md5cksum.data)
+                OBD_FREE(md5cksum.data, md5cksum.len);
+        return ret;
+}