LXR linux/net/sunrpc/auth_gss/gss_spkm3

   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#include <linux/pagemap.h>
  43#include <linux/scatterlist.h>
  44#include <linux/sunrpc/xdr.h>
  45
  46#ifdef RPC_DEBUG
  47# define RPCDBG_FACILITY        RPCDBG_AUTH
  48#endif
  49
  50const struct xdr_netobj hmac_md5_oid = { 8, "\x2B\x06\x01\x05\x05\x08\x01\x01"};
  51const struct xdr_netobj cast5_cbc_oid = {9, "\x2A\x86\x48\x86\xF6\x7D\x07\x42\x0A"};
  52
  53/*
  54 * spkm3_make_token()
  55 *
  56 * Only SPKM_MIC_TOK with md5 intg-alg is supported
  57 */
  58
  59u32
  60spkm3_make_token(struct spkm3_ctx *ctx,
  61                   struct xdr_buf * text, struct xdr_netobj * token,
  62                   int toktype)
  63{
  64        s32                     checksum_type;
  65        char                    tokhdrbuf[25];
  66        char                    cksumdata[16];
  67        struct xdr_netobj       md5cksum = {.len = 0, .data = cksumdata};
  68        struct xdr_netobj       mic_hdr = {.len = 0, .data = tokhdrbuf};
  69        int                     tokenlen = 0;
  70        unsigned char           *ptr;
  71        s32                     now;
  72        int                     ctxelen = 0, ctxzbit = 0;
  73        int                     md5elen = 0, md5zbit = 0;
  74
  75        now = jiffies;
  76
  77        if (ctx->ctx_id.len != 16) {
  78                dprintk("RPC:       spkm3_make_token BAD ctx_id.len %d\n",
  79                                ctx->ctx_id.len);
  80                goto out_err;
  81        }
  82
  83        if (!g_OID_equal(&ctx->intg_alg, &hmac_md5_oid)) {
  84                dprintk("RPC:       gss_spkm3_seal: unsupported I-ALG "
  85                                "algorithm.  only support hmac-md5 I-ALG.\n");
  86                goto out_err;
  87        } else
  88                checksum_type = CKSUMTYPE_HMAC_MD5;
  89
  90        if (!g_OID_equal(&ctx->conf_alg, &cast5_cbc_oid)) {
  91                dprintk("RPC:       gss_spkm3_seal: unsupported C-ALG "
  92                                "algorithm\n");
  93                goto out_err;
  94        }
  95
  96        if (toktype == SPKM_MIC_TOK) {
  97                /* Calculate checksum over the mic-header */
  98                asn1_bitstring_len(&ctx->ctx_id, &ctxelen, &ctxzbit);
  99                spkm3_mic_header(&mic_hdr.data, &mic_hdr.len, ctx->ctx_id.data,
 100                                ctxelen, ctxzbit);
 101                if (make_spkm3_checksum(checksum_type, &ctx->derived_integ_key,
 102                                        (char *)mic_hdr.data, mic_hdr.len,
 103                                        text, 0, &md5cksum))
 104                        goto out_err;
 105
 106                asn1_bitstring_len(&md5cksum, &md5elen, &md5zbit);
 107                tokenlen = 10 + ctxelen + 1 + md5elen + 1;
 108
 109                /* Create token header using generic routines */
 110                token->len = g_token_size(&ctx->mech_used, tokenlen + 2);
 111
 112                ptr = token->data;
 113                g_make_token_header(&ctx->mech_used, tokenlen + 2, &ptr);
 114
 115                spkm3_make_mic_token(&ptr, tokenlen, &mic_hdr, &md5cksum, md5elen, md5zbit);
 116        } else if (toktype == SPKM_WRAP_TOK) { /* Not Supported */
 117                dprintk("RPC:       gss_spkm3_seal: SPKM_WRAP_TOK "
 118                                "not supported\n");
 119                goto out_err;
 120        }
 121
 122        /* XXX need to implement sequence numbers, and ctx->expired */
 123
 124        return  GSS_S_COMPLETE;
 125out_err:
 126        token->data = NULL;
 127        token->len = 0;
 128        return GSS_S_FAILURE;
 129}
 130
 131static int
 132spkm3_checksummer(struct scatterlist *sg, void *data)
 133{
 134        struct hash_desc *desc = data;
 135
 136        return crypto_hash_update(desc, sg, sg->length);
 137}
 138
 139/* checksum the plaintext data and hdrlen bytes of the token header */
 140s32
 141make_spkm3_checksum(s32 cksumtype, struct xdr_netobj *key, char *header,
 142                    unsigned int hdrlen, struct xdr_buf *body,
 143                    unsigned int body_offset, struct xdr_netobj *cksum)
 144{
 145        char                            *cksumname;
 146        struct hash_desc                desc; /* XXX add to ctx? */
 147        struct scatterlist              sg[1];
 148        int err;
 149
 150        switch (cksumtype) {
 151                case CKSUMTYPE_HMAC_MD5:
 152                        cksumname = "hmac(md5)";
 153                        break;
 154                default:
 155                        dprintk("RPC:       spkm3_make_checksum:"
 156                                        " unsupported checksum %d", cksumtype);
 157                        return GSS_S_FAILURE;
 158        }
 159
 160        if (key->data == NULL || key->len <= 0) return GSS_S_FAILURE;
 161
 162        desc.tfm = crypto_alloc_hash(cksumname, 0, CRYPTO_ALG_ASYNC);
 163        if (IS_ERR(desc.tfm))
 164                return GSS_S_FAILURE;
 165        cksum->len = crypto_hash_digestsize(desc.tfm);
 166        desc.flags = CRYPTO_TFM_REQ_MAY_SLEEP;
 167
 168        err = crypto_hash_setkey(desc.tfm, key->data, key->len);
 169        if (err)
 170                goto out;
 171
 172        err = crypto_hash_init(&desc);
 173        if (err)
 174                goto out;
 175
 176        sg_init_one(sg, header, hdrlen);
 177        crypto_hash_update(&desc, sg, sg->length);
 178
 179        xdr_process_buf(body, body_offset, body->len - body_offset,
 180                        spkm3_checksummer, &desc);
 181        crypto_hash_final(&desc, cksum->data);
 182
 183out:
 184        crypto_free_hash(desc.tfm);
 185
 186        return err ? GSS_S_FAILURE : 0;
 187}
 188