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/in.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_tfm **res)
  83 {
  84         struct xdr_netobj       key;
  85         int                     alg, alg_mode;
  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 = "des";
  98                         alg_mode = CRYPTO_TFM_MODE_CBC;
  99                         break;
 100                 default:
 101                         dprintk("RPC:      get_key: unsupported algorithm %d\n", alg);
 102                         goto out_err_free_key;
 103         }
 104         if (!(*res = crypto_alloc_tfm(alg_name, alg_mode)))
 105                 goto out_err_free_key;
 106         if (crypto_cipher_setkey(*res, key.data, key.len))
 107                 goto out_err_free_tfm;
 108
 109         kfree(key.data);
 110         return p;
 111
 112 out_err_free_tfm:
 113         crypto_free_tfm(*res);
 114 out_err_free_key:
 115         kfree(key.data);
 116         p = ERR_PTR(-EINVAL);
 117 out_err:
 118         return p;
 119 }
 120
 121 static int
 122 gss_import_sec_context_kerberos(const void *p,
 123                                 size_t len,
 124                                 struct gss_ctx *ctx_id)
 125 {
 126         const void *end = (const void *)((const char *)p + len);
 127         struct  krb5_ctx *ctx;
 128
 129         if (!(ctx = kmalloc(sizeof(*ctx), GFP_KERNEL)))
 130                 goto out_err;
 131         memset(ctx, 0, sizeof(*ctx));
 132
 133         p = simple_get_bytes(p, end, &ctx->initiate, sizeof(ctx->initiate));
 134         if (IS_ERR(p))
 135                 goto out_err_free_ctx;
 136         p = simple_get_bytes(p, end, &ctx->seed_init, sizeof(ctx->seed_init));
 137         if (IS_ERR(p))
 138                 goto out_err_free_ctx;
 139         p = simple_get_bytes(p, end, ctx->seed, sizeof(ctx->seed));
 140         if (IS_ERR(p))
 141                 goto out_err_free_ctx;
 142         p = simple_get_bytes(p, end, &ctx->signalg, sizeof(ctx->signalg));
 143         if (IS_ERR(p))
 144                 goto out_err_free_ctx;
 145         p = simple_get_bytes(p, end, &ctx->sealalg, sizeof(ctx->sealalg));
 146         if (IS_ERR(p))
 147                 goto out_err_free_ctx;
 148         p = simple_get_bytes(p, end, &ctx->endtime, sizeof(ctx->endtime));
 149         if (IS_ERR(p))
 150                 goto out_err_free_ctx;
 151         p = simple_get_bytes(p, end, &ctx->seq_send, sizeof(ctx->seq_send));
 152         if (IS_ERR(p))
 153                 goto out_err_free_ctx;
 154         p = simple_get_netobj(p, end, &ctx->mech_used);
 155         if (IS_ERR(p))
 156                 goto out_err_free_ctx;
 157         p = get_key(p, end, &ctx->enc);
 158         if (IS_ERR(p))
 159                 goto out_err_free_mech;
 160         p = get_key(p, end, &ctx->seq);
 161         if (IS_ERR(p))
 162                 goto out_err_free_key1;
 163         if (p != end) {
 164                 p = ERR_PTR(-EFAULT);
 165                 goto out_err_free_key2;
 166         }
 167
 168         ctx_id->internal_ctx_id = ctx;
 169         dprintk("RPC:      Succesfully imported new context.\n");
 170         return 0;
 171
 172 out_err_free_key2:
 173         crypto_free_tfm(ctx->seq);
 174 out_err_free_key1:
 175         crypto_free_tfm(ctx->enc);
 176 out_err_free_mech:
 177         kfree(ctx->mech_used.data);
 178 out_err_free_ctx:
 179         kfree(ctx);
 180 out_err:
 181         return PTR_ERR(p);
 182 }
 183
 184 static void
 185 gss_delete_sec_context_kerberos(void *internal_ctx) {
 186         struct krb5_ctx *kctx = internal_ctx;
 187
 188         if (kctx->seq)
 189                 crypto_free_tfm(kctx->seq);
 190         if (kctx->enc)
 191                 crypto_free_tfm(kctx->enc);
 192         if (kctx->mech_used.data)
 193                 kfree(kctx->mech_used.data);
 194         kfree(kctx);
 195 }
 196
 197 static u32
 198 gss_verify_mic_kerberos(struct gss_ctx          *ctx,
 199                         struct xdr_buf          *message,
 200                         struct xdr_netobj       *mic_token,
 201                         u32                     *qstate) {
 202         u32 maj_stat = 0;
 203         int qop_state;
 204         struct krb5_ctx *kctx = ctx->internal_ctx_id;
 205
 206         maj_stat = krb5_read_token(kctx, mic_token, message, &qop_state,
 207                                    KG_TOK_MIC_MSG);
 208         if (!maj_stat && qop_state)
 209             *qstate = qop_state;
 210
 211         dprintk("RPC:      gss_verify_mic_kerberos returning %d\n", maj_stat);
 212         return maj_stat;
 213 }
 214
 215 static u32
 216 gss_get_mic_kerberos(struct gss_ctx     *ctx,
 217                      u32                qop,
 218                      struct xdr_buf     *message,
 219                      struct xdr_netobj  *mic_token) {
 220         u32 err = 0;
 221         struct krb5_ctx *kctx = ctx->internal_ctx_id;
 222
 223         err = krb5_make_token(kctx, qop, message, mic_token, KG_TOK_MIC_MSG);
 224
 225         dprintk("RPC:      gss_get_mic_kerberos returning %d\n",err);
 226
 227         return err;
 228 }
 229
 230 static struct gss_api_ops gss_kerberos_ops = {
 231         .gss_import_sec_context = gss_import_sec_context_kerberos,
 232         .gss_get_mic            = gss_get_mic_kerberos,
 233         .gss_verify_mic         = gss_verify_mic_kerberos,
 234         .gss_delete_sec_context = gss_delete_sec_context_kerberos,
 235 };
 236
 237 static struct pf_desc gss_kerberos_pfs[] = {
 238         [0] = {
 239                 .pseudoflavor = RPC_AUTH_GSS_KRB5,
 240                 .service = RPC_GSS_SVC_NONE,
 241                 .name = "krb5",
 242         },
 243         [1] = {
 244                 .pseudoflavor = RPC_AUTH_GSS_KRB5I,
 245                 .service = RPC_GSS_SVC_INTEGRITY,
 246                 .name = "krb5i",
 247         },
 248 };
 249
 250 static struct gss_api_mech gss_kerberos_mech = {
 251         .gm_name        = "krb5",
 252         .gm_owner       = THIS_MODULE,
 253         .gm_ops         = &gss_kerberos_ops,
 254         .gm_pf_num      = ARRAY_SIZE(gss_kerberos_pfs),
 255         .gm_pfs         = gss_kerberos_pfs,
 256 };
 257
 258 static int __init init_kerberos_module(void)
 259 {
 260         int status;
 261
 262         status = gss_mech_register(&gss_kerberos_mech);
 263         if (status)
 264                 printk("Failed to register kerberos gss mechanism!\n");
 265         return status;
 266 }
 267
 268 static void __exit cleanup_kerberos_module(void)
 269 {
 270         gss_mech_unregister(&gss_kerberos_mech);
 271 }
 272
 273 MODULE_LICENSE("GPL");
 274 module_init(init_kerberos_module);
 275 module_exit(cleanup_kerberos_module);