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/err.h>
  38 #include <linux/module.h>
  39 #include <linux/init.h>
  40 #include <linux/types.h>
  41 #include <linux/slab.h>
  42 #include <linux/sunrpc/auth.h>
  43 #include <linux/sunrpc/gss_krb5.h>
  44 #include <linux/sunrpc/xdr.h>
  45 #include <linux/crypto.h>
  46
  47 #ifdef RPC_DEBUG
  48 # define RPCDBG_FACILITY        RPCDBG_AUTH
  49 #endif
  50
  51 static const void *
  52 simple_get_bytes(const void *p, const void *end, void *res, int len)
  53 {
  54         const void *q = (const void *)((const char *)p + len);
  55         if (unlikely(q > end || q < p))
  56                 return ERR_PTR(-EFAULT);
  57         memcpy(res, p, len);
  58         return q;
  59 }
  60
  61 static const void *
  62 simple_get_netobj(const void *p, const void *end, struct xdr_netobj *res)
  63 {
  64         const void *q;
  65         unsigned int len;
  66
  67         p = simple_get_bytes(p, end, &len, sizeof(len));
  68         if (IS_ERR(p))
  69                 return p;
  70         q = (const void *)((const char *)p + len);
  71         if (unlikely(q > end || q < p))
  72                 return ERR_PTR(-EFAULT);
  73         res->data = kmalloc(len, GFP_KERNEL);
  74         if (unlikely(res->data == NULL))
  75                 return ERR_PTR(-ENOMEM);
  76         memcpy(res->data, p, len);
  77         res->len = len;
  78         return q;
  79 }
  80
  81 static inline const void *
  82 get_key(const void *p, const void *end, struct crypto_blkcipher **res)
  83 {
  84         struct xdr_netobj       key;
  85         int                     alg;
  86         char                    *alg_name;
  87
  88         p = simple_get_bytes(p, end, &alg, sizeof(alg));
  89         if (IS_ERR(p))
  90                 goto out_err;
  91         p = simple_get_netobj(p, end, &key);
  92         if (IS_ERR(p))
  93                 goto out_err;
  94
  95         switch (alg) {
  96                 case ENCTYPE_DES_CBC_RAW:
  97                         alg_name = "cbc(des)";
  98                         break;
  99                 default:
 100                         printk("gss_kerberos_mech: unsupported algorithm %d\n", alg);
 101                         goto out_err_free_key;
 102         }
 103         *res = crypto_alloc_blkcipher(alg_name, 0, CRYPTO_ALG_ASYNC);
 104         if (IS_ERR(*res)) {
 105                 printk("gss_kerberos_mech: unable to initialize crypto algorithm %s\n", alg_name);
 106                 *res = NULL;
 107                 goto out_err_free_key;
 108         }
 109         if (crypto_blkcipher_setkey(*res, key.data, key.len)) {
 110                 printk("gss_kerberos_mech: error setting key for crypto algorithm %s\n", alg_name);
 111                 goto out_err_free_tfm;
 112         }
 113
 114         kfree(key.data);
 115         return p;
 116
 117 out_err_free_tfm:
 118         crypto_free_blkcipher(*res);
 119 out_err_free_key:
 120         kfree(key.data);
 121         p = ERR_PTR(-EINVAL);
 122 out_err:
 123         return p;
 124 }
 125
 126 static int
 127 gss_import_sec_context_kerberos(const void *p,
 128                                 size_t len,
 129                                 struct gss_ctx *ctx_id)
 130 {
 131         const void *end = (const void *)((const char *)p + len);
 132         struct  krb5_ctx *ctx;
 133
 134         if (!(ctx = kzalloc(sizeof(*ctx), GFP_KERNEL)))
 135                 goto out_err;
 136
 137         p = simple_get_bytes(p, end, &ctx->initiate, sizeof(ctx->initiate));
 138         if (IS_ERR(p))
 139                 goto out_err_free_ctx;
 140         p = simple_get_bytes(p, end, &ctx->seed_init, sizeof(ctx->seed_init));
 141         if (IS_ERR(p))
 142                 goto out_err_free_ctx;
 143         p = simple_get_bytes(p, end, ctx->seed, sizeof(ctx->seed));
 144         if (IS_ERR(p))
 145                 goto out_err_free_ctx;
 146         p = simple_get_bytes(p, end, &ctx->signalg, sizeof(ctx->signalg));
 147         if (IS_ERR(p))
 148                 goto out_err_free_ctx;
 149         p = simple_get_bytes(p, end, &ctx->sealalg, sizeof(ctx->sealalg));
 150         if (IS_ERR(p))
 151                 goto out_err_free_ctx;
 152         p = simple_get_bytes(p, end, &ctx->endtime, sizeof(ctx->endtime));
 153         if (IS_ERR(p))
 154                 goto out_err_free_ctx;
 155         p = simple_get_bytes(p, end, &ctx->seq_send, sizeof(ctx->seq_send));
 156         if (IS_ERR(p))
 157                 goto out_err_free_ctx;
 158         p = simple_get_netobj(p, end, &ctx->mech_used);
 159         if (IS_ERR(p))
 160                 goto out_err_free_ctx;
 161         p = get_key(p, end, &ctx->enc);
 162         if (IS_ERR(p))
 163                 goto out_err_free_mech;
 164         p = get_key(p, end, &ctx->seq);
 165         if (IS_ERR(p))
 166                 goto out_err_free_key1;
 167         if (p != end) {
 168                 p = ERR_PTR(-EFAULT);
 169                 goto out_err_free_key2;
 170         }
 171
 172         ctx_id->internal_ctx_id = ctx;
 173         dprintk("RPC:      Successfully imported new context.\n");
 174         return 0;
 175
 176 out_err_free_key2:
 177         crypto_free_blkcipher(ctx->seq);
 178 out_err_free_key1:
 179         crypto_free_blkcipher(ctx->enc);
 180 out_err_free_mech:
 181         kfree(ctx->mech_used.data);
 182 out_err_free_ctx:
 183         kfree(ctx);
 184 out_err:
 185         return PTR_ERR(p);
 186 }
 187
 188 static void
 189 gss_delete_sec_context_kerberos(void *internal_ctx) {
 190         struct krb5_ctx *kctx = internal_ctx;
 191
 192         crypto_free_blkcipher(kctx->seq);
 193         crypto_free_blkcipher(kctx->enc);
 194         kfree(kctx->mech_used.data);
 195         kfree(kctx);
 196 }
 197
 198 static struct gss_api_ops gss_kerberos_ops = {
 199         .gss_import_sec_context = gss_import_sec_context_kerberos,
 200         .gss_get_mic            = gss_get_mic_kerberos,
 201         .gss_verify_mic         = gss_verify_mic_kerberos,
 202         .gss_wrap               = gss_wrap_kerberos,
 203         .gss_unwrap             = gss_unwrap_kerberos,
 204         .gss_delete_sec_context = gss_delete_sec_context_kerberos,
 205 };
 206
 207 static struct pf_desc gss_kerberos_pfs[] = {
 208         [0] = {
 209                 .pseudoflavor = RPC_AUTH_GSS_KRB5,
 210                 .service = RPC_GSS_SVC_NONE,
 211                 .name = "krb5",
 212         },
 213         [1] = {
 214                 .pseudoflavor = RPC_AUTH_GSS_KRB5I,
 215                 .service = RPC_GSS_SVC_INTEGRITY,
 216                 .name = "krb5i",
 217         },
 218         [2] = {
 219                 .pseudoflavor = RPC_AUTH_GSS_KRB5P,
 220                 .service = RPC_GSS_SVC_PRIVACY,
 221                 .name = "krb5p",
 222         },
 223 };
 224
 225 static struct gss_api_mech gss_kerberos_mech = {
 226         .gm_name        = "krb5",
 227         .gm_owner       = THIS_MODULE,
 228         .gm_ops         = &gss_kerberos_ops,
 229         .gm_pf_num      = ARRAY_SIZE(gss_kerberos_pfs),
 230         .gm_pfs         = gss_kerberos_pfs,
 231 };
 232
 233 static int __init init_kerberos_module(void)
 234 {
 235         int status;
 236
 237         status = gss_mech_register(&gss_kerberos_mech);
 238         if (status)
 239                 printk("Failed to register kerberos gss mechanism!\n");
 240         return status;
 241 }
 242
 243 static void __exit cleanup_kerberos_module(void)
 244 {
 245         gss_mech_unregister(&gss_kerberos_mech);
 246 }
 247
 248 MODULE_LICENSE("GPL");
 249 module_init(init_kerberos_module);
 250 module_exit(cleanup_kerberos_module);