diff options
Diffstat (limited to 'net/sunrpc/auth_gss/gss_krb5_unseal.c')
| -rw-r--r-- | net/sunrpc/auth_gss/gss_krb5_unseal.c | 128 |
1 files changed, 128 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 000000000..4fbc50a0a --- /dev/null +++ b/net/sunrpc/auth_gss/gss_krb5_unseal.c @@ -0,0 +1,128 @@ +/* + * 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 <crypto/algapi.h> +#include <linux/types.h> +#include <linux/jiffies.h> +#include <linux/sunrpc/gss_krb5.h> +#include <linux/crypto.h> + +#include "gss_krb5_internal.h" + +#if IS_ENABLED(CONFIG_SUNRPC_DEBUG) +# define RPCDBG_FACILITY RPCDBG_AUTH +#endif + +u32 +gss_krb5_verify_mic_v2(struct krb5_ctx *ctx, struct xdr_buf *message_buffer, + struct xdr_netobj *read_token) +{ + struct crypto_ahash *tfm = ctx->initiate ? + ctx->acceptor_sign : ctx->initiator_sign; + char cksumdata[GSS_KRB5_MAX_CKSUM_LEN]; + struct xdr_netobj cksumobj = { + .len = ctx->gk5e->cksumlength, + .data = cksumdata, + }; + u8 *ptr = read_token->data; + __be16 be16_ptr; + time64_t now; + u8 flags; + int i; + + dprintk("RPC: %s\n", __func__); + + memcpy(&be16_ptr, (char *) ptr, 2); + 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 (gss_krb5_checksum(tfm, ptr, GSS_KRB5_TOK_HDR_LEN, + message_buffer, 0, &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 = ktime_get_real_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; +} |