net/sunrpc/auth_gss/gss_krb5_mech.c

   1 /*
   2  *  linux/net/sunrpc/gss_krb5_mech.c
   3  *
   4  *  Copyright (c) 2001 The Regents of the University of Michigan.
   5  *  All rights reserved.
   6  *
   7  *  Andy Adamson <andros@umich.edu>
   8  *  J. Bruce Fields <bfields@umich.edu>
   9  *
  10  *  Redistribution and use in source and binary forms, with or without
  11  *  modification, are permitted provided that the following conditions
  12  *  are met:
  13  *
  14  *  1. Redistributions of source code must retain the above copyright
  15  *     notice, this list of conditions and the following disclaimer.
  16  *  2. Redistributions in binary form must reproduce the above copyright
  17  *     notice, this list of conditions and the following disclaimer in the
  18  *     documentation and/or other materials provided with the distribution.
  19  *  3. Neither the name of the University nor the names of its
  20  *     contributors may be used to endorse or promote products derived
  21  *     from this software without specific prior written permission.
  22  *
  23  *  THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
  24  *  WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
  25  *  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  26  *  DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  27  *  FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  28  *  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  29  *  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
  30  *  BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
  31  *  LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
  32  *  NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
  33  *  SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  34  *
  35  */
  36
  37 #include <linux/module.h>
  38 #include <linux/init.h>
  39 #include <linux/types.h>
  40 #include <linux/slab.h>
  41 #include <linux/sunrpc/auth.h>
  42 #include <linux/sunrpc/gss_krb5.h>
  43 #include <linux/sunrpc/xdr.h>
  44 #include <linux/crypto.h>
  45
  46 #ifdef RPC_DEBUG
  47 # define RPCDBG_FACILITY        RPCDBG_AUTH
  48 #endif
  49
  50 static const void *
  51 simple_get_bytes(const void *p, const void *end, void *res, int len)
  52 {
  53         const void *q = (const void *)((const char *)p + len);
  54         if (unlikely(q > end || q < p))
  55                 return ERR_PTR(-EFAULT);
  56         memcpy(res, p, len);
  57         return q;
  58 }
  59
  60 static const void *
  61 simple_get_netobj(const void *p, const void *end, struct xdr_netobj *res)
  62 {
  63         const void *q;
  64         unsigned int len;
  65
  66         p = simple_get_bytes(p, end, &len, sizeof(len));
  67         if (IS_ERR(p))
  68                 return p;
  69         q = (const void *)((const char *)p + len);
  70         if (unlikely(q > end || q < p))
  71                 return ERR_PTR(-EFAULT);
  72         res->data = kmalloc(len, GFP_KERNEL);
  73         if (unlikely(res->data == NULL))
  74                 return ERR_PTR(-ENOMEM);
  75         memcpy(res->data, p, len);
  76         res->len = len;
  77         return q;
  78 }
  79
  80 static inline const void *
  81 get_key(const void *p, const void *end, struct crypto_tfm **res)
  82 {
  83         struct xdr_netobj       key;
  84         int                     alg, alg_mode;
  85         char                    *alg_name;
  86
  87         p = simple_get_bytes(p, end, &alg, sizeof(alg));
  88         if (IS_ERR(p))
  89                 goto out_err;
  90         p = simple_get_netobj(p, end, &key);
  91         if (IS_ERR(p))
  92                 goto out_err;
  93
  94         switch (alg) {
  95                 case ENCTYPE_DES_CBC_RAW:
  96                         alg_name = "des";
  97                         alg_mode = CRYPTO_TFM_MODE_CBC;
  98                         break;
  99                 default:
 100                         printk("gss_kerberos_mech: unsupported algorithm %d\n", alg);
 101                         goto out_err_free_key;
 102         }
 103         if (!(*res = crypto_alloc_tfm(alg_name, alg_mode))) {
 104                 printk("gss_kerberos_mech: unable to initialize crypto algorithm %s\n", alg_name);
 105                 goto out_err_free_key;
 106         }
 107         if (crypto_cipher_setkey(*res, key.data, key.len)) {
 108                 printk("gss_kerberos_mech: error setting key for crypto algorithm %s\n", alg_name);
 109                 goto out_err_free_tfm;
 110         }
 111
 112         kfree(key.data);
 113         return p;
 114
 115 out_err_free_tfm:
 116         crypto_free_tfm(*res);
 117 out_err_free_key:
 118         kfree(key.data);
 119         p = ERR_PTR(-EINVAL);
 120 out_err:
 121         return p;
 122 }
 123
 124 static int
 125 gss_import_sec_context_kerberos(const void *p,
 126                                 size_t len,
 127                                 struct gss_ctx *ctx_id)
 128 {
 129         const void *end = (const void *)((const char *)p + len);
 130         struct  krb5_ctx *ctx;
 131
 132         if (!(ctx = kmalloc(sizeof(*ctx), GFP_KERNEL)))
 133                 goto out_err;
 134         memset(ctx, 0, sizeof(*ctx));
 135
 136         p = simple_get_bytes(p, end, &ctx->initiate, sizeof(ctx->initiate));
 137         if (IS_ERR(p))
 138                 goto out_err_free_ctx;
 139         p = simple_get_bytes(p, end, &ctx->seed_init, sizeof(ctx->seed_init));
 140         if (IS_ERR(p))
 141                 goto out_err_free_ctx;
 142         p = simple_get_bytes(p, end, ctx->seed, sizeof(ctx->seed));
 143         if (IS_ERR(p))
 144                 goto out_err_free_ctx;
 145         p = simple_get_bytes(p, end, &ctx->signalg, sizeof(ctx->signalg));
 146         if (IS_ERR(p))
 147                 goto out_err_free_ctx;
 148         p = simple_get_bytes(p, end, &ctx->sealalg, sizeof(ctx->sealalg));
 149         if (IS_ERR(p))
 150                 goto out_err_free_ctx;
 151         p = simple_get_bytes(p, end, &ctx->endtime, sizeof(ctx->endtime));
 152         if (IS_ERR(p))
 153                 goto out_err_free_ctx;
 154         p = simple_get_bytes(p, end, &ctx->seq_send, sizeof(ctx->seq_send));
 155         if (IS_ERR(p))
 156                 goto out_err_free_ctx;
 157         p = simple_get_netobj(p, end, &ctx->mech_used);
 158         if (IS_ERR(p))
 159                 goto out_err_free_ctx;
 160         p = get_key(p, end, &ctx->enc);
 161         if (IS_ERR(p))
 162                 goto out_err_free_mech;
 163         p = get_key(p, end, &ctx->seq);
 164         if (IS_ERR(p))
 165                 goto out_err_free_key1;
 166         if (p != end) {
 167                 p = ERR_PTR(-EFAULT);
 168                 goto out_err_free_key2;
 169         }
 170
 171         ctx_id->internal_ctx_id = ctx;
 172         dprintk("RPC:      Successfully imported new context.\n");
 173         return 0;
 174
 175 out_err_free_key2:
 176         crypto_free_tfm(ctx->seq);
 177 out_err_free_key1:
 178         crypto_free_tfm(ctx->enc);
 179 out_err_free_mech:
 180         kfree(ctx->mech_used.data);
 181 out_err_free_ctx:
 182         kfree(ctx);
 183 out_err:
 184         return PTR_ERR(p);
 185 }
 186
 187 static void
 188 gss_delete_sec_context_kerberos(void *internal_ctx) {
 189         struct krb5_ctx *kctx = internal_ctx;
 190
 191         crypto_free_tfm(kctx->seq);
 192         crypto_free_tfm(kctx->enc);
 193         kfree(kctx->mech_used.data);
 194         kfree(kctx);
 195 }
 196
 197 static struct gss_api_ops gss_kerberos_ops = {
 198         .gss_import_sec_context = gss_import_sec_context_kerberos,
 199         .gss_get_mic            = gss_get_mic_kerberos,
 200         .gss_verify_mic         = gss_verify_mic_kerberos,
 201         .gss_wrap               = gss_wrap_kerberos,
 202         .gss_unwrap             = gss_unwrap_kerberos,
 203         .gss_delete_sec_context = gss_delete_sec_context_kerberos,
 204 };
 205
 206 static struct pf_desc gss_kerberos_pfs[] = {
 207         [0] = {
 208                 .pseudoflavor = RPC_AUTH_GSS_KRB5,
 209                 .service = RPC_GSS_SVC_NONE,
 210                 .name = "krb5",
 211         },
 212         [1] = {
 213                 .pseudoflavor = RPC_AUTH_GSS_KRB5I,
 214                 .service = RPC_GSS_SVC_INTEGRITY,
 215                 .name = "krb5i",
 216         },
 217         [2] = {
 218                 .pseudoflavor = RPC_AUTH_GSS_KRB5P,
 219                 .service = RPC_GSS_SVC_PRIVACY,
 220                 .name = "krb5p",
 221         },
 222 };
 223
 224 static struct gss_api_mech gss_kerberos_mech = {
 225         .gm_name        = "krb5",
 226         .gm_owner       = THIS_MODULE,
 227         .gm_ops         = &gss_kerberos_ops,
 228         .gm_pf_num      = ARRAY_SIZE(gss_kerberos_pfs),
 229         .gm_pfs         = gss_kerberos_pfs,
 230 };
 231
 232 static int __init init_kerberos_module(void)
 233 {
 234         int status;
 235
 236         status = gss_mech_register(&gss_kerberos_mech);
 237         if (status)
 238                 printk("Failed to register kerberos gss mechanism!\n");
 239         return status;
 240 }
 241
 242 static void __exit cleanup_kerberos_module(void)
 243 {
 244         gss_mech_unregister(&gss_kerberos_mech);
 245 }
 246
 247 MODULE_LICENSE("GPL");
 248 module_init(init_kerberos_module);
 249 module_exit(cleanup_kerberos_module);