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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
51static const void *
52simple_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
61static const void *
62simple_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 = kmemdup(p, len, GFP_NOFS);
74 if (unlikely(res->data == NULL))
75 return ERR_PTR(-ENOMEM);
76 res->len = len;
77 return q;
78}
79
80static inline const void *
81get_key(const void *p, const void *end, struct crypto_blkcipher **res)
82{
83 struct xdr_netobj key;
84 int alg;
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 = "cbc(des)";
97 break;
98 default:
99 printk("gss_kerberos_mech: unsupported algorithm %d\n", alg);
100 goto out_err_free_key;
101 }
102 *res = crypto_alloc_blkcipher(alg_name, 0, CRYPTO_ALG_ASYNC);
103 if (IS_ERR(*res)) {
104 printk("gss_kerberos_mech: unable to initialize crypto algorithm %s\n", alg_name);
105 *res = NULL;
106 goto out_err_free_key;
107 }
108 if (crypto_blkcipher_setkey(*res, key.data, key.len)) {
109 printk("gss_kerberos_mech: error setting key for crypto algorithm %s\n", alg_name);
110 goto out_err_free_tfm;
111 }
112
113 kfree(key.data);
114 return p;
115
116out_err_free_tfm:
117 crypto_free_blkcipher(*res);
118out_err_free_key:
119 kfree(key.data);
120 p = ERR_PTR(-EINVAL);
121out_err:
122 return p;
123}
124
125static int
126gss_import_sec_context_kerberos(const void *p,
127 size_t len,
128 struct gss_ctx *ctx_id)
129{
130 const void *end = (const void *)((const char *)p + len);
131 struct krb5_ctx *ctx;
132 int tmp;
133
134 if (!(ctx = kzalloc(sizeof(*ctx), GFP_NOFS)))
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
141
142
143
144 if (unlikely(p + 20 > end || p + 20 < p))
145 goto out_err_free_ctx;
146 p += 20;
147 p = simple_get_bytes(p, end, &tmp, sizeof(tmp));
148 if (IS_ERR(p))
149 goto out_err_free_ctx;
150 if (tmp != SGN_ALG_DES_MAC_MD5) {
151 p = ERR_PTR(-ENOSYS);
152 goto out_err_free_ctx;
153 }
154 p = simple_get_bytes(p, end, &tmp, sizeof(tmp));
155 if (IS_ERR(p))
156 goto out_err_free_ctx;
157 if (tmp != SEAL_ALG_DES) {
158 p = ERR_PTR(-ENOSYS);
159 goto out_err_free_ctx;
160 }
161 p = simple_get_bytes(p, end, &ctx->endtime, sizeof(ctx->endtime));
162 if (IS_ERR(p))
163 goto out_err_free_ctx;
164 p = simple_get_bytes(p, end, &ctx->seq_send, sizeof(ctx->seq_send));
165 if (IS_ERR(p))
166 goto out_err_free_ctx;
167 p = simple_get_netobj(p, end, &ctx->mech_used);
168 if (IS_ERR(p))
169 goto out_err_free_ctx;
170 p = get_key(p, end, &ctx->enc);
171 if (IS_ERR(p))
172 goto out_err_free_mech;
173 p = get_key(p, end, &ctx->seq);
174 if (IS_ERR(p))
175 goto out_err_free_key1;
176 if (p != end) {
177 p = ERR_PTR(-EFAULT);
178 goto out_err_free_key2;
179 }
180
181 ctx_id->internal_ctx_id = ctx;
182
183 dprintk("RPC: Successfully imported new context.\n");
184 return 0;
185
186out_err_free_key2:
187 crypto_free_blkcipher(ctx->seq);
188out_err_free_key1:
189 crypto_free_blkcipher(ctx->enc);
190out_err_free_mech:
191 kfree(ctx->mech_used.data);
192out_err_free_ctx:
193 kfree(ctx);
194out_err:
195 return PTR_ERR(p);
196}
197
198static void
199gss_delete_sec_context_kerberos(void *internal_ctx) {
200 struct krb5_ctx *kctx = internal_ctx;
201
202 crypto_free_blkcipher(kctx->seq);
203 crypto_free_blkcipher(kctx->enc);
204 kfree(kctx->mech_used.data);
205 kfree(kctx);
206}
207
208static const struct gss_api_ops gss_kerberos_ops = {
209 .gss_import_sec_context = gss_import_sec_context_kerberos,
210 .gss_get_mic = gss_get_mic_kerberos,
211 .gss_verify_mic = gss_verify_mic_kerberos,
212 .gss_wrap = gss_wrap_kerberos,
213 .gss_unwrap = gss_unwrap_kerberos,
214 .gss_delete_sec_context = gss_delete_sec_context_kerberos,
215};
216
217static struct pf_desc gss_kerberos_pfs[] = {
218 [0] = {
219 .pseudoflavor = RPC_AUTH_GSS_KRB5,
220 .service = RPC_GSS_SVC_NONE,
221 .name = "krb5",
222 },
223 [1] = {
224 .pseudoflavor = RPC_AUTH_GSS_KRB5I,
225 .service = RPC_GSS_SVC_INTEGRITY,
226 .name = "krb5i",
227 },
228 [2] = {
229 .pseudoflavor = RPC_AUTH_GSS_KRB5P,
230 .service = RPC_GSS_SVC_PRIVACY,
231 .name = "krb5p",
232 },
233};
234
235static struct gss_api_mech gss_kerberos_mech = {
236 .gm_name = "krb5",
237 .gm_owner = THIS_MODULE,
238 .gm_oid = {9, (void *)"\x2a\x86\x48\x86\xf7\x12\x01\x02\x02"},
239 .gm_ops = &gss_kerberos_ops,
240 .gm_pf_num = ARRAY_SIZE(gss_kerberos_pfs),
241 .gm_pfs = gss_kerberos_pfs,
242};
243
244static int __init init_kerberos_module(void)
245{
246 int status;
247
248 status = gss_mech_register(&gss_kerberos_mech);
249 if (status)
250 printk("Failed to register kerberos gss mechanism!\n");
251 return status;
252}
253
254static void __exit cleanup_kerberos_module(void)
255{
256 gss_mech_unregister(&gss_kerberos_mech);
257}
258
259MODULE_LICENSE("GPL");
260module_init(init_kerberos_module);
261module_exit(cleanup_kerberos_module);
262
