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,
  55                    struct xdr_buf * text, struct xdr_netobj * token,
  56                    int toktype)
  57 {
  58         s32                     checksum_type;
  59         char                    tokhdrbuf[25];
  60         char                    cksumdata[16];
  61         struct xdr_netobj       md5cksum = {.len = 0, .data = cksumdata};
  62         struct xdr_netobj       mic_hdr = {.len = 0, .data = tokhdrbuf};
  63         int                     tokenlen = 0;
  64         unsigned char           *ptr;
  65         s32                     now;
  66         int                     ctxelen = 0, ctxzbit = 0;
  67         int                     md5elen = 0, md5zbit = 0;
  68
  69         dprintk("RPC: spkm3_make_token\n");
  70
  71         now = jiffies;
  72
  73         if (ctx->ctx_id.len != 16) {
  74                 dprintk("RPC: spkm3_make_token BAD ctx_id.len %d\n",
  75                         ctx->ctx_id.len);
  76                 goto out_err;
  77         }
  78
  79         switch (ctx->intg_alg) {
  80                 case NID_md5:
  81                         checksum_type = CKSUMTYPE_RSA_MD5;
  82                         break;
  83                 default:
  84                         dprintk("RPC: gss_spkm3_seal: ctx->signalg %d not"
  85                                 " supported\n", ctx->intg_alg);
  86                         goto out_err;
  87         }
  88         /* XXX since we don't support WRAP, perhaps we don't care... */
  89         if (ctx->conf_alg != NID_cast5_cbc) {
  90                 dprintk("RPC: gss_spkm3_seal: ctx->sealalg %d not supported\n",
  91                         ctx->conf_alg);
  92                 goto out_err;
  93         }
  94
  95         if (toktype == SPKM_MIC_TOK) {
  96                 /* Calculate checksum over the mic-header */
  97                 asn1_bitstring_len(&ctx->ctx_id, &ctxelen, &ctxzbit);
  98                 spkm3_mic_header(&mic_hdr.data, &mic_hdr.len, ctx->ctx_id.data,
  99                                          ctxelen, ctxzbit);
 100
 101                 if (make_checksum(checksum_type, mic_hdr.data, mic_hdr.len,
 102                                              text, 0, &md5cksum))
 103                         goto out_err;
 104
 105                 asn1_bitstring_len(&md5cksum, &md5elen, &md5zbit);
 106                 tokenlen = 10 + ctxelen + 1 + md5elen + 1;
 107
 108                 /* Create token header using generic routines */
 109                 token->len = g_token_size(&ctx->mech_used, tokenlen);
 110
 111                 ptr = token->data;
 112                 g_make_token_header(&ctx->mech_used, tokenlen, &ptr);
 113
 114                 spkm3_make_mic_token(&ptr, tokenlen, &mic_hdr, &md5cksum, md5elen, md5zbit);
 115         } else if (toktype == SPKM_WRAP_TOK) { /* Not Supported */
 116                 dprintk("RPC: gss_spkm3_seal: SPKM_WRAP_TOK not supported\n");
 117                 goto out_err;
 118         }
 119
 120         /* XXX need to implement sequence numbers, and ctx->expired */
 121
 122         return  GSS_S_COMPLETE;
 123 out_err:
 124         token->data = NULL;
 125         token->len = 0;
 126         return GSS_S_FAILURE;
 127 }