1 files changed, 202 insertions, 0 deletions
diff --git a/net/sunrpc/auth_gss/gss_krb5_unseal.c b/net/sunrpc/auth_gss/gss_krb5_unseal.c
new file mode 100644
index 000000000000..8767fc53183d
--- /dev/null
+++ b/net/sunrpc/auth_gss/gss_krb5_unseal.c
@@ -0,0 +1,202 @@
+/*
+ *  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.
+ */
+
+#include <linux/types.h>
+#include <linux/slab.h>
+#include <linux/jiffies.h>
+#include <linux/sunrpc/gss_krb5.h>
+#include <linux/crypto.h>
+
+#ifdef RPC_DEBUG
+# define RPCDBG_FACILITY        RPCDBG_AUTH
+#endif
+
+
+/* message_buffer is an input if toktype is MIC and an output if it is WRAP:
+ * If toktype is MIC: read_token is a mic token, and message_buffer is the
+ *   data that the mic was supposedly taken over.
+ * If toktype is WRAP: read_token is a wrap token, and message_buffer is used
+ *   to return the decrypted data.
+ */
+
+/* XXX will need to change prototype and/or just split into a separate function
+ * when we add privacy (because read_token will be in pages too). */
+u32
+krb5_read_token(struct krb5_ctx *ctx,
+		struct xdr_netobj *read_token,
+		struct xdr_buf *message_buffer,
+		int *qop_state, int toktype)
+{
+	int			signalg;
+	int			sealalg;
+	s32			checksum_type;
+	struct xdr_netobj	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;
+
+	dprintk("RPC:      krb5_read_token\n");
+
+	if (g_verify_token_header(&ctx->mech_used, &bodysize, &ptr,
+					read_token->len))
+		goto out;
+
+	if ((*ptr++ != ((toktype>>8)&0xff)) || (*ptr++ != (toktype&0xff)))
+		goto out;
+
+	/* XXX sanity-check bodysize?? */
+
+	if (toktype == KG_TOK_WRAP_MSG) {
+		/* XXX gone */
+		goto out;
+	}
+
+	/* 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 (((toktype != KG_TOK_WRAP_MSG) && (sealalg != 0xffff)) ||
+	    ((toktype == KG_TOK_WRAP_MSG) && (sealalg == 0xffff)))
+		goto out;
+
+	/* in the current spec, there is only one valid seal algorithm per
+	   key type, so a simple comparison is ok */
+
+	if ((toktype == KG_TOK_WRAP_MSG) && !(sealalg == ctx->sealalg))
+		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) kfree(md5cksum.data);
+	return ret;
+}