net/sunrpc/auth_gss/gss_spkm3_seal.c

   1 /*
   2  *  linux/net/sunrpc/gss_spkm3_seal.c
   3  *
   4  *  Copyright (c) 2003 The Regents of the University of Michigan.
   5  *  All rights reserved.
   6  *
   7  *  Andy Adamson <andros@umich.edu>
   8  *
   9  *  Redistribution and use in source and binary forms, with or without
  10  *  modification, are permitted provided that the following conditions
  11  *  are met:
  12  *
  13  *  1. Redistributions of source code must retain the above copyright
  14  *     notice, this list of conditions and the following disclaimer.
  15  *  2. Redistributions in binary form must reproduce the above copyright
  16  *     notice, this list of conditions and the following disclaimer in the
  17  *     documentation and/or other materials provided with the distribution.
  18  *  3. Neither the name of the University nor the names of its
  19  *     contributors may be used to endorse or promote products derived
  20  *     from this software without specific prior written permission.
  21  *
  22  *  THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
  23  *  WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
  24  *  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  25  *  DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  26  *  FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  27  *  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  28  *  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
  29  *  BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
  30  *  LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
  31  *  NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
  32  *  SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  33  *
  34  */
  35
  36 #include <linux/types.h>
  37 #include <linux/slab.h>
  38 #include <linux/jiffies.h>
  39 #include <linux/sunrpc/gss_spkm3.h>
  40 #include <linux/random.h>
  41 #include <linux/crypto.h>
  42
  43 #ifdef RPC_DEBUG
  44 # define RPCDBG_FACILITY        RPCDBG_AUTH
  45 #endif
  46
  47 /*
  48  * spkm3_make_token()
  49  *
  50  * Only SPKM_MIC_TOK with md5 intg-alg is supported
  51  */
  52
  53 u32
  54 spkm3_make_token(struct spkm3_ctx *ctx, int qop_req,
  55                    struct xdr_buf * text, struct xdr_netobj * token,
  56                    int toktype)
  57 {
  58         s32                     checksum_type;
  59         char                    tokhdrbuf[25];
  60         struct xdr_netobj       md5cksum = {.len = 0, .data = NULL};
  61         struct xdr_netobj       mic_hdr = {.len = 0, .data = tokhdrbuf};
  62         int                     tmsglen, tokenlen = 0;
  63         unsigned char           *ptr;
  64         s32                     now;
  65         int                     ctxelen = 0, ctxzbit = 0;
  66         int                     md5elen = 0, md5zbit = 0;
  67
  68         dprintk("RPC: spkm3_make_token\n");
  69
  70         now = jiffies;
  71         if (qop_req != 0)
  72                 goto out_err;
  73
  74         if (ctx->ctx_id.len != 16) {
  75                 dprintk("RPC: spkm3_make_token BAD ctx_id.len %d\n",
  76                         ctx->ctx_id.len);
  77                 goto out_err;
  78         }
  79
  80         switch (ctx->intg_alg) {
  81                 case NID_md5:
  82                         checksum_type = CKSUMTYPE_RSA_MD5;
  83                         break;
  84                 default:
  85                         dprintk("RPC: gss_spkm3_seal: ctx->signalg %d not"
  86                                 " supported\n", ctx->intg_alg);
  87                         goto out_err;
  88         }
  89         /* XXX since we don't support WRAP, perhaps we don't care... */
  90         if (ctx->conf_alg != NID_cast5_cbc) {
  91                 dprintk("RPC: gss_spkm3_seal: ctx->sealalg %d not supported\n",
  92                         ctx->conf_alg);
  93                 goto out_err;
  94         }
  95
  96         if (toktype == SPKM_MIC_TOK) {
  97                 tmsglen = 0;
  98                 /* Calculate checksum over the mic-header */
  99                 asn1_bitstring_len(&ctx->ctx_id, &ctxelen, &ctxzbit);
 100                 spkm3_mic_header(&mic_hdr.data, &mic_hdr.len, ctx->ctx_id.data,
 101                                          ctxelen, ctxzbit);
 102
 103                 if (make_checksum(checksum_type, mic_hdr.data, mic_hdr.len,
 104                                              text, &md5cksum))
 105                         goto out_err;
 106
 107                 asn1_bitstring_len(&md5cksum, &md5elen, &md5zbit);
 108                 tokenlen = 10 + ctxelen + 1 + 2 + md5elen + 1;
 109
 110                 /* Create token header using generic routines */
 111                 token->len = g_token_size(&ctx->mech_used, tokenlen + tmsglen);
 112
 113                 ptr = token->data;
 114                 g_make_token_header(&ctx->mech_used, tokenlen + tmsglen, &ptr);
 115
 116                 spkm3_make_mic_token(&ptr, tokenlen, &mic_hdr, &md5cksum, md5elen, md5zbit);
 117         } else if (toktype == SPKM_WRAP_TOK) { /* Not Supported */
 118                 dprintk("RPC: gss_spkm3_seal: SPKM_WRAP_TOK not supported\n");
 119                 goto out_err;
 120         }
 121         kfree(md5cksum.data);
 122
 123         /* XXX need to implement sequence numbers, and ctx->expired */
 124
 125         return  GSS_S_COMPLETE;
 126 out_err:
 127         if (md5cksum.data)
 128                 kfree(md5cksum.data);
 129         token->data = NULL;
 130         token->len = 0;
 131         return GSS_S_FAILURE;
 132 }