--- /dev/null
+/*
+ * linux/net/sunrpc/gss_krb5_unseal.c
+ *
+ * Adapted from MIT Kerberos 5-1.2.1 lib/gssapi/krb5/k5unseal.c
+ *
+ * Copyright (c) 2000-2008 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/jiffies.h>
+#include <linux/sunrpc/gss_krb5.h>
+#include <linux/crypto.h>
+
+#if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
+# define RPCDBG_FACILITY RPCDBG_AUTH
+#endif
+
+
+/* read_token is a mic token, and message_buffer is the data that the mic was
+ * supposedly taken over. */
+
+static u32
+gss_verify_mic_v1(struct krb5_ctx *ctx,
+ struct xdr_buf *message_buffer, struct xdr_netobj *read_token)
+{
+ int signalg;
+ int sealalg;
+ char cksumdata[GSS_KRB5_MAX_CKSUM_LEN];
+ struct xdr_netobj md5cksum = {.len = sizeof(cksumdata),
+ .data = cksumdata};
+ s32 now;
+ int direction;
+ u32 seqnum;
+ unsigned char *ptr = (unsigned char *)read_token->data;
+ int bodysize;
+ u8 *cksumkey;
+
+ dprintk("RPC: krb5_read_token\n");
+
+ if (g_verify_token_header(&ctx->mech_used, &bodysize, &ptr,
+ read_token->len))
+ return GSS_S_DEFECTIVE_TOKEN;
+
+ if ((ptr[0] != ((KG_TOK_MIC_MSG >> 8) & 0xff)) ||
+ (ptr[1] != (KG_TOK_MIC_MSG & 0xff)))
+ return GSS_S_DEFECTIVE_TOKEN;
+
+ /* XXX sanity-check bodysize?? */
+
+ signalg = ptr[2] + (ptr[3] << 8);
+ if (signalg != ctx->gk5e->signalg)
+ return GSS_S_DEFECTIVE_TOKEN;
+
+ sealalg = ptr[4] + (ptr[5] << 8);
+ if (sealalg != SEAL_ALG_NONE)
+ return GSS_S_DEFECTIVE_TOKEN;
+
+ if ((ptr[6] != 0xff) || (ptr[7] != 0xff))
+ return GSS_S_DEFECTIVE_TOKEN;
+
+ if (ctx->gk5e->keyed_cksum)
+ cksumkey = ctx->cksum;
+ else
+ cksumkey = NULL;
+
+ if (make_checksum(ctx, ptr, 8, message_buffer, 0,
+ cksumkey, KG_USAGE_SIGN, &md5cksum))
+ return GSS_S_FAILURE;
+
+ if (memcmp(md5cksum.data, ptr + GSS_KRB5_TOK_HDR_LEN,
+ ctx->gk5e->cksumlength))
+ return GSS_S_BAD_SIG;
+
+ /* it got through unscathed. Make sure the context is unexpired */
+
+ now = get_seconds();
+
+ if (now > ctx->endtime)
+ return GSS_S_CONTEXT_EXPIRED;
+
+ /* do sequencing checks */
+
+ if (krb5_get_seq_num(ctx, ptr + GSS_KRB5_TOK_HDR_LEN, ptr + 8,
+ &direction, &seqnum))
+ return GSS_S_FAILURE;
+
+ if ((ctx->initiate && direction != 0xff) ||
+ (!ctx->initiate && direction != 0))
+ return GSS_S_BAD_SIG;
+
+ return GSS_S_COMPLETE;
+}
+
+static u32
+gss_verify_mic_v2(struct krb5_ctx *ctx,
+ struct xdr_buf *message_buffer, struct xdr_netobj *read_token)
+{
+ char cksumdata[GSS_KRB5_MAX_CKSUM_LEN];
+ struct xdr_netobj cksumobj = {.len = sizeof(cksumdata),
+ .data = cksumdata};
+ s32 now;
+ u8 *ptr = read_token->data;
+ u8 *cksumkey;
+ u8 flags;
+ int i;
+ unsigned int cksum_usage;
+
+ dprintk("RPC: %s\n", __func__);
+
+ if (be16_to_cpu(*((__be16 *)ptr)) != KG2_TOK_MIC)
+ return GSS_S_DEFECTIVE_TOKEN;
+
+ flags = ptr[2];
+ if ((!ctx->initiate && (flags & KG2_TOKEN_FLAG_SENTBYACCEPTOR)) ||
+ (ctx->initiate && !(flags & KG2_TOKEN_FLAG_SENTBYACCEPTOR)))
+ return GSS_S_BAD_SIG;
+
+ if (flags & KG2_TOKEN_FLAG_SEALED) {
+ dprintk("%s: token has unexpected sealed flag\n", __func__);
+ return GSS_S_FAILURE;
+ }
+
+ for (i = 3; i < 8; i++)
+ if (ptr[i] != 0xff)
+ return GSS_S_DEFECTIVE_TOKEN;
+
+ if (ctx->initiate) {
+ cksumkey = ctx->acceptor_sign;
+ cksum_usage = KG_USAGE_ACCEPTOR_SIGN;
+ } else {
+ cksumkey = ctx->initiator_sign;
+ cksum_usage = KG_USAGE_INITIATOR_SIGN;
+ }
+
+ if (make_checksum_v2(ctx, ptr, GSS_KRB5_TOK_HDR_LEN, message_buffer, 0,
+ cksumkey, cksum_usage, &cksumobj))
+ return GSS_S_FAILURE;
+
+ if (memcmp(cksumobj.data, ptr + GSS_KRB5_TOK_HDR_LEN,
+ ctx->gk5e->cksumlength))
+ return GSS_S_BAD_SIG;
+
+ /* it got through unscathed. Make sure the context is unexpired */
+ now = get_seconds();
+ if (now > ctx->endtime)
+ return GSS_S_CONTEXT_EXPIRED;
+
+ /*
+ * NOTE: the sequence number at ptr + 8 is skipped, rpcsec_gss
+ * doesn't want it checked; see page 6 of rfc 2203.
+ */
+
+ return GSS_S_COMPLETE;
+}
+
+u32
+gss_verify_mic_kerberos(struct gss_ctx *gss_ctx,
+ struct xdr_buf *message_buffer,
+ struct xdr_netobj *read_token)
+{
+ struct krb5_ctx *ctx = gss_ctx->internal_ctx_id;
+
+ switch (ctx->enctype) {
+ default:
+ BUG();
+ case ENCTYPE_DES_CBC_RAW:
+ case ENCTYPE_DES3_CBC_RAW:
+ case ENCTYPE_ARCFOUR_HMAC:
+ return gss_verify_mic_v1(ctx, message_buffer, read_token);
+ case ENCTYPE_AES128_CTS_HMAC_SHA1_96:
+ case ENCTYPE_AES256_CTS_HMAC_SHA1_96:
+ return gss_verify_mic_v2(ctx, message_buffer, read_token);
+ }
+}
+
Code Review / kvmfornfv.git / blobdiff