linux/net/sunrpc/auth_gss/gss_krb5_mech.c

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/*
* linux/net/sunrpc/gss_krb5_mech.c
*
* Copyright (c) 2001-2008 The Regents of the University of Michigan.
* All rights reserved.
*
* Andy Adamson <andros@umich.edu>
* J. Bruce Fields <bfields@umich.edu>
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the University nor the names of its
* contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
* BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
*/
#include <linux/err.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/types.h>
#include <linux/slab.h>
#include <linux/sunrpc/auth.h>
#include <linux/sunrpc/gss_krb5.h>
#include <linux/sunrpc/xdr.h>
#include <linux/crypto.h>
#ifdef RPC_DEBUG
# define RPCDBG_FACILITY RPCDBG_AUTH
#endif
static const struct gss_krb5_enctype supported_gss_krb5_enctypes[] = {
/*
* DES (All DES enctypes are mapped to the same gss functionality)
*/
{
.etype = ENCTYPE_DES_CBC_RAW,
.ctype = CKSUMTYPE_RSA_MD5,
.name = "des-cbc-crc",
.encrypt_name = "cbc(des)",
.cksum_name = "md5",
.encrypt = krb5_encrypt,
.decrypt = krb5_decrypt,
.signalg = SGN_ALG_DES_MAC_MD5,
.sealalg = SEAL_ALG_DES,
.keybytes = 7,
.keylength = 8,
.blocksize = 8,
.cksumlength = 8,
},
};
static const int num_supported_enctypes =
ARRAY_SIZE(supported_gss_krb5_enctypes);
static int
supported_gss_krb5_enctype(int etype)
{
int i;
for (i = 0; i < num_supported_enctypes; i++)
if (supported_gss_krb5_enctypes[i].etype == etype)
return 1;
return 0;
}
static const struct gss_krb5_enctype *
get_gss_krb5_enctype(int etype)
{
int i;
for (i = 0; i < num_supported_enctypes; i++)
if (supported_gss_krb5_enctypes[i].etype == etype)
return &supported_gss_krb5_enctypes[i];
return NULL;
}
static const void *
simple_get_bytes(const void *p, const void *end, void *res, int len)
{
const void *q = (const void *)((const char *)p + len);
if (unlikely(q > end || q < p))
return ERR_PTR(-EFAULT);
memcpy(res, p, len);
return q;
}
static const void *
simple_get_netobj(const void *p, const void *end, struct xdr_netobj *res)
{
const void *q;
unsigned int len;
p = simple_get_bytes(p, end, &len, sizeof(len));
if (IS_ERR(p))
return p;
q = (const void *)((const char *)p + len);
if (unlikely(q > end || q < p))
return ERR_PTR(-EFAULT);
res->data = kmemdup(p, len, GFP_NOFS);
if (unlikely(res->data == NULL))
return ERR_PTR(-ENOMEM);
res->len = len;
return q;
}
static inline const void *
get_key(const void *p, const void *end,
struct krb5_ctx *ctx, struct crypto_blkcipher **res)
{
struct xdr_netobj key;
int alg;
p = simple_get_bytes(p, end, &alg, sizeof(alg));
if (IS_ERR(p))
goto out_err;
switch (alg) {
case ENCTYPE_DES_CBC_CRC:
case ENCTYPE_DES_CBC_MD4:
case ENCTYPE_DES_CBC_MD5:
/* Map all these key types to ENCTYPE_DES_CBC_RAW */
alg = ENCTYPE_DES_CBC_RAW;
break;
}
if (!supported_gss_krb5_enctype(alg)) {
printk(KERN_WARNING "gss_kerberos_mech: unsupported "
"encryption key algorithm %d\n", alg);
goto out_err;
}
p = simple_get_netobj(p, end, &key);
if (IS_ERR(p))
goto out_err;
*res = crypto_alloc_blkcipher(ctx->gk5e->encrypt_name, 0,
CRYPTO_ALG_ASYNC);
if (IS_ERR(*res)) {
printk(KERN_WARNING "gss_kerberos_mech: unable to initialize "
"crypto algorithm %s\n", ctx->gk5e->encrypt_name);
*res = NULL;
goto out_err_free_key;
}
if (crypto_blkcipher_setkey(*res, key.data, key.len)) {
printk(KERN_WARNING "gss_kerberos_mech: error setting key for "
"crypto algorithm %s\n", ctx->gk5e->encrypt_name);
goto out_err_free_tfm;
}
kfree(key.data);
return p;
out_err_free_tfm:
crypto_free_blkcipher(*res);
out_err_free_key:
kfree(key.data);
p = ERR_PTR(-EINVAL);
out_err:
return p;
}
static int
gss_import_v1_context(const void *p, const void *end, struct krb5_ctx *ctx)
{
int tmp;
p = simple_get_bytes(p, end, &ctx->initiate, sizeof(ctx->initiate));
if (IS_ERR(p))
goto out_err;
/* Old format supports only DES! Any other enctype uses new format */
ctx->enctype = ENCTYPE_DES_CBC_RAW;
ctx->gk5e = get_gss_krb5_enctype(ctx->enctype);
if (ctx->gk5e == NULL)
goto out_err;
/* The downcall format was designed before we completely understood
* the uses of the context fields; so it includes some stuff we
* just give some minimal sanity-checking, and some we ignore
* completely (like the next twenty bytes): */
if (unlikely(p + 20 > end || p + 20 < p))
goto out_err;
p += 20;
p = simple_get_bytes(p, end, &tmp, sizeof(tmp));
if (IS_ERR(p))
goto out_err;
if (tmp != SGN_ALG_DES_MAC_MD5) {
p = ERR_PTR(-ENOSYS);
goto out_err;
}
p = simple_get_bytes(p, end, &tmp, sizeof(tmp));
if (IS_ERR(p))
goto out_err;
if (tmp != SEAL_ALG_DES) {
p = ERR_PTR(-ENOSYS);
goto out_err;
}
p = simple_get_bytes(p, end, &ctx->endtime, sizeof(ctx->endtime));
if (IS_ERR(p))
goto out_err;
p = simple_get_bytes(p, end, &ctx->seq_send, sizeof(ctx->seq_send));
if (IS_ERR(p))
goto out_err;
p = simple_get_netobj(p, end, &ctx->mech_used);
if (IS_ERR(p))
goto out_err;
p = get_key(p, end, ctx, &ctx->enc);
if (IS_ERR(p))
goto out_err_free_mech;
p = get_key(p, end, ctx, &ctx->seq);
if (IS_ERR(p))
goto out_err_free_key1;
if (p != end) {
p = ERR_PTR(-EFAULT);
goto out_err_free_key2;
}
return 0;
out_err_free_key2:
crypto_free_blkcipher(ctx->seq);
out_err_free_key1:
crypto_free_blkcipher(ctx->enc);
out_err_free_mech:
kfree(ctx->mech_used.data);
out_err:
return PTR_ERR(p);
}
static int
gss_import_sec_context_kerberos(const void *p, size_t len,
struct gss_ctx *ctx_id)
{
const void *end = (const void *)((const char *)p + len);
struct krb5_ctx *ctx;
int ret;
ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
if (ctx == NULL)
return -ENOMEM;
if (len == 85)
ret = gss_import_v1_context(p, end, ctx);
else
ret = -EINVAL;
if (ret == 0)
ctx_id->internal_ctx_id = ctx;
else
kfree(ctx);
dprintk("RPC: %s: returning %d\n", __func__, ret);
return ret;
}
static void
gss_delete_sec_context_kerberos(void *internal_ctx) {
struct krb5_ctx *kctx = internal_ctx;
crypto_free_blkcipher(kctx->seq);
crypto_free_blkcipher(kctx->enc);
kfree(kctx->mech_used.data);
kfree(kctx);
}
static const struct gss_api_ops gss_kerberos_ops = {
.gss_import_sec_context = gss_import_sec_context_kerberos,
.gss_get_mic = gss_get_mic_kerberos,
.gss_verify_mic = gss_verify_mic_kerberos,
.gss_wrap = gss_wrap_kerberos,
.gss_unwrap = gss_unwrap_kerberos,
.gss_delete_sec_context = gss_delete_sec_context_kerberos,
};
static struct pf_desc gss_kerberos_pfs[] = {
[0] = {
.pseudoflavor = RPC_AUTH_GSS_KRB5,
.service = RPC_GSS_SVC_NONE,
.name = "krb5",
},
[1] = {
.pseudoflavor = RPC_AUTH_GSS_KRB5I,
.service = RPC_GSS_SVC_INTEGRITY,
.name = "krb5i",
},
[2] = {
.pseudoflavor = RPC_AUTH_GSS_KRB5P,
.service = RPC_GSS_SVC_PRIVACY,
.name = "krb5p",
},
};
static struct gss_api_mech gss_kerberos_mech = {
.gm_name = "krb5",
.gm_owner = THIS_MODULE,
.gm_oid = {9, (void *)"\x2a\x86\x48\x86\xf7\x12\x01\x02\x02"},
.gm_ops = &gss_kerberos_ops,
.gm_pf_num = ARRAY_SIZE(gss_kerberos_pfs),
.gm_pfs = gss_kerberos_pfs,
};
static int __init init_kerberos_module(void)
{
int status;
status = gss_mech_register(&gss_kerberos_mech);
if (status)
printk("Failed to register kerberos gss mechanism!\n");
return status;
}
static void __exit cleanup_kerberos_module(void)
{
gss_mech_unregister(&gss_kerberos_mech);
}
MODULE_LICENSE("GPL");
module_init(init_kerberos_module);
module_exit(cleanup_kerberos_module);