cregit-Linux how code gets into the kernel

Release 4.8 net/sunrpc/auth_gss/gss_krb5_unseal.c

/*
 *  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; }

Contributors

PersonTokensPropCommitsCommitProp
trond myklebusttrond myklebust23966.39%527.78%
kevin coffmankevin coffman6518.06%633.33%
j. bruce fieldsj. bruce fields5515.28%633.33%
chuck leverchuck lever10.28%15.56%
Total360100.00%18100.00%


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; }

Contributors

PersonTokensPropCommitsCommitProp
kevin coffmankevin coffman27699.64%266.67%
j. bruce fieldsj. bruce fields10.36%133.33%
Total277100.00%3100.00%


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); } }

Contributors

PersonTokensPropCommitsCommitProp
kevin coffmankevin coffman76100.00%4100.00%
Total76100.00%4100.00%


Overall Contributors

PersonTokensPropCommitsCommitProp
kevin coffmankevin coffman41856.41%939.13%
trond myklebusttrond myklebust25934.95%521.74%
j. bruce fieldsj. bruce fields577.69%730.43%
jeff laytonjeff layton60.81%14.35%
chuck leverchuck lever10.13%14.35%
Total741100.00%23100.00%
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