1 /*
2  *  linux/include/linux/sunrpc/gss_krb5_types.h
3  *
4  *  Adapted from MIT Kerberos 5-1.2.1 lib/include/krb5.h,
5  *  lib/gssapi/krb5/gssapiP_krb5.h, and others
6  *
7  *  Copyright (c) 2000-2008 The Regents of the University of Michigan.
8  *  All rights reserved.
9  *
10  *  Andy Adamson   <andros@umich.edu>
11  *  Bruce Fields   <bfields@umich.edu>
12  */
13 
14 /*
15  * Copyright 1995 by the Massachusetts Institute of Technology.
16  * All Rights Reserved.
17  *
18  * Export of this software from the United States of America may
19  *   require a specific license from the United States Government.
20  *   It is the responsibility of any person or organization contemplating
21  *   export to obtain such a license before exporting.
22  *
23  * WITHIN THAT CONSTRAINT, permission to use, copy, modify, and
24  * distribute this software and its documentation for any purpose and
25  * without fee is hereby granted, provided that the above copyright
26  * notice appear in all copies and that both that copyright notice and
27  * this permission notice appear in supporting documentation, and that
28  * the name of M.I.T. not be used in advertising or publicity pertaining
29  * to distribution of the software without specific, written prior
30  * permission.  Furthermore if you modify this software you must label
31  * your software as modified software and not distribute it in such a
32  * fashion that it might be confused with the original M.I.T. software.
33  * M.I.T. makes no representations about the suitability of
34  * this software for any purpose.  It is provided "as is" without express
35  * or implied warranty.
36  *
37  */
38 
39 #include <crypto/skcipher.h>
40 #include <linux/sunrpc/auth_gss.h>
41 #include <linux/sunrpc/gss_err.h>
42 #include <linux/sunrpc/gss_asn1.h>
43 
44 /* Length of constant used in key derivation */
45 #define GSS_KRB5_K5CLENGTH (5)
46 
47 /* Maximum key length (in bytes) for the supported crypto algorithms*/
48 #define GSS_KRB5_MAX_KEYLEN (32)
49 
50 /* Maximum checksum function output for the supported crypto algorithms */
51 #define GSS_KRB5_MAX_CKSUM_LEN  (20)
52 
53 /* Maximum blocksize for the supported crypto algorithms */
54 #define GSS_KRB5_MAX_BLOCKSIZE  (16)
55 
56 struct krb5_ctx;
57 
58 struct gss_krb5_enctype {
59 	const u32		etype;		/* encryption (key) type */
60 	const u32		ctype;		/* checksum type */
61 	const char		*name;		/* "friendly" name */
62 	const char		*encrypt_name;	/* crypto encrypt name */
63 	const char		*cksum_name;	/* crypto checksum name */
64 	const u16		signalg;	/* signing algorithm */
65 	const u16		sealalg;	/* sealing algorithm */
66 	const u32		blocksize;	/* encryption blocksize */
67 	const u32		conflen;	/* confounder length
68 						   (normally the same as
69 						   the blocksize) */
70 	const u32		cksumlength;	/* checksum length */
71 	const u32		keyed_cksum;	/* is it a keyed cksum? */
72 	const u32		keybytes;	/* raw key len, in bytes */
73 	const u32		keylength;	/* final key len, in bytes */
74 	u32 (*encrypt) (struct crypto_sync_skcipher *tfm,
75 			void *iv, void *in, void *out,
76 			int length);		/* encryption function */
77 	u32 (*decrypt) (struct crypto_sync_skcipher *tfm,
78 			void *iv, void *in, void *out,
79 			int length);		/* decryption function */
80 	u32 (*mk_key) (const struct gss_krb5_enctype *gk5e,
81 		       struct xdr_netobj *in,
82 		       struct xdr_netobj *out);	/* complete key generation */
83 	u32 (*encrypt_v2) (struct krb5_ctx *kctx, u32 offset,
84 			   struct xdr_buf *buf,
85 			   struct page **pages); /* v2 encryption function */
86 	u32 (*decrypt_v2) (struct krb5_ctx *kctx, u32 offset, u32 len,
87 			   struct xdr_buf *buf, u32 *headskip,
88 			   u32 *tailskip);	/* v2 decryption function */
89 };
90 
91 /* krb5_ctx flags definitions */
92 #define KRB5_CTX_FLAG_INITIATOR         0x00000001
93 #define KRB5_CTX_FLAG_CFX               0x00000002
94 #define KRB5_CTX_FLAG_ACCEPTOR_SUBKEY   0x00000004
95 
96 struct krb5_ctx {
97 	int			initiate; /* 1 = initiating, 0 = accepting */
98 	u32			enctype;
99 	u32			flags;
100 	const struct gss_krb5_enctype *gk5e; /* enctype-specific info */
101 	struct crypto_sync_skcipher *enc;
102 	struct crypto_sync_skcipher *seq;
103 	struct crypto_sync_skcipher *acceptor_enc;
104 	struct crypto_sync_skcipher *initiator_enc;
105 	struct crypto_sync_skcipher *acceptor_enc_aux;
106 	struct crypto_sync_skcipher *initiator_enc_aux;
107 	u8			Ksess[GSS_KRB5_MAX_KEYLEN]; /* session key */
108 	u8			cksum[GSS_KRB5_MAX_KEYLEN];
109 	atomic_t		seq_send;
110 	atomic64_t		seq_send64;
111 	time64_t		endtime;
112 	struct xdr_netobj	mech_used;
113 	u8			initiator_sign[GSS_KRB5_MAX_KEYLEN];
114 	u8			acceptor_sign[GSS_KRB5_MAX_KEYLEN];
115 	u8			initiator_seal[GSS_KRB5_MAX_KEYLEN];
116 	u8			acceptor_seal[GSS_KRB5_MAX_KEYLEN];
117 	u8			initiator_integ[GSS_KRB5_MAX_KEYLEN];
118 	u8			acceptor_integ[GSS_KRB5_MAX_KEYLEN];
119 };
120 
121 /* The length of the Kerberos GSS token header */
122 #define GSS_KRB5_TOK_HDR_LEN	(16)
123 
124 #define KG_TOK_MIC_MSG    0x0101
125 #define KG_TOK_WRAP_MSG   0x0201
126 
127 #define KG2_TOK_INITIAL     0x0101
128 #define KG2_TOK_RESPONSE    0x0202
129 #define KG2_TOK_MIC         0x0404
130 #define KG2_TOK_WRAP        0x0504
131 
132 #define KG2_TOKEN_FLAG_SENTBYACCEPTOR   0x01
133 #define KG2_TOKEN_FLAG_SEALED           0x02
134 #define KG2_TOKEN_FLAG_ACCEPTORSUBKEY   0x04
135 
136 #define KG2_RESP_FLAG_ERROR             0x0001
137 #define KG2_RESP_FLAG_DELEG_OK          0x0002
138 
139 enum sgn_alg {
140 	SGN_ALG_DES_MAC_MD5 = 0x0000,
141 	SGN_ALG_MD2_5 = 0x0001,
142 	SGN_ALG_DES_MAC = 0x0002,
143 	SGN_ALG_3 = 0x0003,		/* not published */
144 	SGN_ALG_HMAC_SHA1_DES3_KD = 0x0004
145 };
146 enum seal_alg {
147 	SEAL_ALG_NONE = 0xffff,
148 	SEAL_ALG_DES = 0x0000,
149 	SEAL_ALG_1 = 0x0001,		/* not published */
150 	SEAL_ALG_DES3KD = 0x0002
151 };
152 
153 #define CKSUMTYPE_CRC32			0x0001
154 #define CKSUMTYPE_RSA_MD4		0x0002
155 #define CKSUMTYPE_RSA_MD4_DES		0x0003
156 #define CKSUMTYPE_DESCBC		0x0004
157 #define CKSUMTYPE_RSA_MD5		0x0007
158 #define CKSUMTYPE_RSA_MD5_DES		0x0008
159 #define CKSUMTYPE_NIST_SHA		0x0009
160 #define CKSUMTYPE_HMAC_SHA1_DES3	0x000c
161 #define CKSUMTYPE_HMAC_SHA1_96_AES128   0x000f
162 #define CKSUMTYPE_HMAC_SHA1_96_AES256   0x0010
163 #define CKSUMTYPE_HMAC_MD5_ARCFOUR      -138 /* Microsoft md5 hmac cksumtype */
164 
165 /* from gssapi_err_krb5.h */
166 #define KG_CCACHE_NOMATCH                        (39756032L)
167 #define KG_KEYTAB_NOMATCH                        (39756033L)
168 #define KG_TGT_MISSING                           (39756034L)
169 #define KG_NO_SUBKEY                             (39756035L)
170 #define KG_CONTEXT_ESTABLISHED                   (39756036L)
171 #define KG_BAD_SIGN_TYPE                         (39756037L)
172 #define KG_BAD_LENGTH                            (39756038L)
173 #define KG_CTX_INCOMPLETE                        (39756039L)
174 #define KG_CONTEXT                               (39756040L)
175 #define KG_CRED                                  (39756041L)
176 #define KG_ENC_DESC                              (39756042L)
177 #define KG_BAD_SEQ                               (39756043L)
178 #define KG_EMPTY_CCACHE                          (39756044L)
179 #define KG_NO_CTYPES                             (39756045L)
180 
181 /* per Kerberos v5 protocol spec crypto types from the wire.
182  * these get mapped to linux kernel crypto routines.
183  */
184 #define ENCTYPE_NULL            0x0000
185 #define ENCTYPE_DES_CBC_CRC     0x0001	/* DES cbc mode with CRC-32 */
186 #define ENCTYPE_DES_CBC_MD4     0x0002	/* DES cbc mode with RSA-MD4 */
187 #define ENCTYPE_DES_CBC_MD5     0x0003	/* DES cbc mode with RSA-MD5 */
188 #define ENCTYPE_DES_CBC_RAW     0x0004	/* DES cbc mode raw */
189 /* XXX deprecated? */
190 #define ENCTYPE_DES3_CBC_SHA    0x0005	/* DES-3 cbc mode with NIST-SHA */
191 #define ENCTYPE_DES3_CBC_RAW    0x0006	/* DES-3 cbc mode raw */
192 #define ENCTYPE_DES_HMAC_SHA1   0x0008
193 #define ENCTYPE_DES3_CBC_SHA1   0x0010
194 #define ENCTYPE_AES128_CTS_HMAC_SHA1_96 0x0011
195 #define ENCTYPE_AES256_CTS_HMAC_SHA1_96 0x0012
196 #define ENCTYPE_ARCFOUR_HMAC            0x0017
197 #define ENCTYPE_ARCFOUR_HMAC_EXP        0x0018
198 #define ENCTYPE_UNKNOWN         0x01ff
199 
200 /*
201  * Constants used for key derivation
202  */
203 /* for 3DES */
204 #define KG_USAGE_SEAL (22)
205 #define KG_USAGE_SIGN (23)
206 #define KG_USAGE_SEQ  (24)
207 
208 /* from rfc3961 */
209 #define KEY_USAGE_SEED_CHECKSUM         (0x99)
210 #define KEY_USAGE_SEED_ENCRYPTION       (0xAA)
211 #define KEY_USAGE_SEED_INTEGRITY        (0x55)
212 
213 /* from rfc4121 */
214 #define KG_USAGE_ACCEPTOR_SEAL  (22)
215 #define KG_USAGE_ACCEPTOR_SIGN  (23)
216 #define KG_USAGE_INITIATOR_SEAL (24)
217 #define KG_USAGE_INITIATOR_SIGN (25)
218 
219 /*
220  * This compile-time check verifies that we will not exceed the
221  * slack space allotted by the client and server auth_gss code
222  * before they call gss_wrap().
223  */
224 #define GSS_KRB5_MAX_SLACK_NEEDED \
225 	(GSS_KRB5_TOK_HDR_LEN     /* gss token header */         \
226 	+ GSS_KRB5_MAX_CKSUM_LEN  /* gss token checksum */       \
227 	+ GSS_KRB5_MAX_BLOCKSIZE  /* confounder */               \
228 	+ GSS_KRB5_MAX_BLOCKSIZE  /* possible padding */         \
229 	+ GSS_KRB5_TOK_HDR_LEN    /* encrypted hdr in v2 token */\
230 	+ GSS_KRB5_MAX_CKSUM_LEN  /* encryption hmac */          \
231 	+ 4 + 4                   /* RPC verifier */             \
232 	+ GSS_KRB5_TOK_HDR_LEN                                   \
233 	+ GSS_KRB5_MAX_CKSUM_LEN)
234 
235 u32
236 make_checksum(struct krb5_ctx *kctx, char *header, int hdrlen,
237 		struct xdr_buf *body, int body_offset, u8 *cksumkey,
238 		unsigned int usage, struct xdr_netobj *cksumout);
239 
240 u32
241 make_checksum_v2(struct krb5_ctx *, char *header, int hdrlen,
242 		 struct xdr_buf *body, int body_offset, u8 *key,
243 		 unsigned int usage, struct xdr_netobj *cksum);
244 
245 u32 gss_get_mic_kerberos(struct gss_ctx *, struct xdr_buf *,
246 		struct xdr_netobj *);
247 
248 u32 gss_verify_mic_kerberos(struct gss_ctx *, struct xdr_buf *,
249 		struct xdr_netobj *);
250 
251 u32
252 gss_wrap_kerberos(struct gss_ctx *ctx_id, int offset,
253 		struct xdr_buf *outbuf, struct page **pages);
254 
255 u32
256 gss_unwrap_kerberos(struct gss_ctx *ctx_id, int offset, int len,
257 		struct xdr_buf *buf);
258 
259 
260 u32
261 krb5_encrypt(struct crypto_sync_skcipher *key,
262 	     void *iv, void *in, void *out, int length);
263 
264 u32
265 krb5_decrypt(struct crypto_sync_skcipher *key,
266 	     void *iv, void *in, void *out, int length);
267 
268 int
269 gss_encrypt_xdr_buf(struct crypto_sync_skcipher *tfm, struct xdr_buf *outbuf,
270 		    int offset, struct page **pages);
271 
272 int
273 gss_decrypt_xdr_buf(struct crypto_sync_skcipher *tfm, struct xdr_buf *inbuf,
274 		    int offset);
275 
276 s32
277 krb5_make_seq_num(struct krb5_ctx *kctx,
278 		struct crypto_sync_skcipher *key,
279 		int direction,
280 		u32 seqnum, unsigned char *cksum, unsigned char *buf);
281 
282 s32
283 krb5_get_seq_num(struct krb5_ctx *kctx,
284 	       unsigned char *cksum,
285 	       unsigned char *buf, int *direction, u32 *seqnum);
286 
287 int
288 xdr_extend_head(struct xdr_buf *buf, unsigned int base, unsigned int shiftlen);
289 
290 u32
291 krb5_derive_key(const struct gss_krb5_enctype *gk5e,
292 		const struct xdr_netobj *inkey,
293 		struct xdr_netobj *outkey,
294 		const struct xdr_netobj *in_constant,
295 		gfp_t gfp_mask);
296 
297 u32
298 gss_krb5_des3_make_key(const struct gss_krb5_enctype *gk5e,
299 		       struct xdr_netobj *randombits,
300 		       struct xdr_netobj *key);
301 
302 u32
303 gss_krb5_aes_make_key(const struct gss_krb5_enctype *gk5e,
304 		      struct xdr_netobj *randombits,
305 		      struct xdr_netobj *key);
306 
307 u32
308 gss_krb5_aes_encrypt(struct krb5_ctx *kctx, u32 offset,
309 		     struct xdr_buf *buf,
310 		     struct page **pages);
311 
312 u32
313 gss_krb5_aes_decrypt(struct krb5_ctx *kctx, u32 offset, u32 len,
314 		     struct xdr_buf *buf, u32 *plainoffset,
315 		     u32 *plainlen);
316 
317 void
318 gss_krb5_make_confounder(char *p, u32 conflen);
319