diff options
Diffstat (limited to 'net/sunrpc/auth_gss/gss_krb5_unseal.c')
| -rw-r--r-- | net/sunrpc/auth_gss/gss_krb5_unseal.c | 226 |
1 files changed, 226 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 00000000..6cd930f3 --- /dev/null +++ b/net/sunrpc/auth_gss/gss_krb5_unseal.c @@ -0,0 +1,226 @@ +/* + * 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> + +#ifdef RPC_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; + u64 seqnum; + 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; + + /* do sequencing checks */ + + seqnum = be64_to_cpup((__be64 *)ptr + 8); + + 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); + } +} + |