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