1/* SPDX-License-Identifier: GPL-2.0 or BSD-3-Clause */
2/*
3 * SunRPC GSS Kerberos 5 mechanism internal definitions
4 *
5 * Copyright (c) 2022 Oracle and/or its affiliates.
6 */
7
8#ifndef _NET_SUNRPC_AUTH_GSS_KRB5_INTERNAL_H
9#define _NET_SUNRPC_AUTH_GSS_KRB5_INTERNAL_H
10
11/*
12 * The RFCs often specify payload lengths in bits. This helper
13 * converts a specified bit-length to the number of octets/bytes.
14 */
15#define BITS2OCTETS(x) ((x) / 8)
16
17struct krb5_ctx;
18
19struct gss_krb5_enctype {
20 const u32 etype; /* encryption (key) type */
21 const u32 ctype; /* checksum type */
22 const char *name; /* "friendly" name */
23 const char *encrypt_name; /* crypto encrypt name */
24 const char *aux_cipher; /* aux encrypt cipher name */
25 const char *cksum_name; /* crypto checksum name */
26 const u16 signalg; /* signing algorithm */
27 const u16 sealalg; /* sealing algorithm */
28 const u32 cksumlength; /* checksum length */
29 const u32 keyed_cksum; /* is it a keyed cksum? */
30 const u32 keybytes; /* raw key len, in bytes */
31 const u32 keylength; /* protocol key length, in octets */
32 const u32 Kc_length; /* checksum subkey length, in octets */
33 const u32 Ke_length; /* encryption subkey length, in octets */
34 const u32 Ki_length; /* integrity subkey length, in octets */
35
36 int (*derive_key)(const struct gss_krb5_enctype *gk5e,
37 const struct xdr_netobj *in,
38 struct xdr_netobj *out,
39 const struct xdr_netobj *label,
40 gfp_t gfp_mask);
41 u32 (*encrypt)(struct krb5_ctx *kctx, u32 offset,
42 struct xdr_buf *buf, struct page **pages);
43 u32 (*decrypt)(struct krb5_ctx *kctx, u32 offset, u32 len,
44 struct xdr_buf *buf, u32 *headskip, u32 *tailskip);
45 u32 (*get_mic)(struct krb5_ctx *kctx, struct xdr_buf *text,
46 struct xdr_netobj *token);
47 u32 (*verify_mic)(struct krb5_ctx *kctx, struct xdr_buf *message_buffer,
48 struct xdr_netobj *read_token);
49 u32 (*wrap)(struct krb5_ctx *kctx, int offset,
50 struct xdr_buf *buf, struct page **pages);
51 u32 (*unwrap)(struct krb5_ctx *kctx, int offset, int len,
52 struct xdr_buf *buf, unsigned int *slack,
53 unsigned int *align);
54};
55
56/* krb5_ctx flags definitions */
57#define KRB5_CTX_FLAG_INITIATOR 0x00000001
58#define KRB5_CTX_FLAG_ACCEPTOR_SUBKEY 0x00000004
59
60struct krb5_ctx {
61 int initiate; /* 1 = initiating, 0 = accepting */
62 u32 enctype;
63 u32 flags;
64 const struct gss_krb5_enctype *gk5e; /* enctype-specific info */
65 struct crypto_sync_skcipher *enc;
66 struct crypto_sync_skcipher *seq;
67 struct crypto_sync_skcipher *acceptor_enc;
68 struct crypto_sync_skcipher *initiator_enc;
69 struct crypto_sync_skcipher *acceptor_enc_aux;
70 struct crypto_sync_skcipher *initiator_enc_aux;
71 struct crypto_ahash *acceptor_sign;
72 struct crypto_ahash *initiator_sign;
73 struct crypto_ahash *initiator_integ;
74 struct crypto_ahash *acceptor_integ;
75 u8 Ksess[GSS_KRB5_MAX_KEYLEN]; /* session key */
76 u8 cksum[GSS_KRB5_MAX_KEYLEN];
77 atomic_t seq_send;
78 atomic64_t seq_send64;
79 time64_t endtime;
80 struct xdr_netobj mech_used;
81};
82
83/*
84 * GSS Kerberos 5 mechanism Per-Message calls.
85 */
86
87u32 gss_krb5_get_mic_v2(struct krb5_ctx *ctx, struct xdr_buf *text,
88 struct xdr_netobj *token);
89
90u32 gss_krb5_verify_mic_v2(struct krb5_ctx *ctx, struct xdr_buf *message_buffer,
91 struct xdr_netobj *read_token);
92
93u32 gss_krb5_wrap_v2(struct krb5_ctx *kctx, int offset,
94 struct xdr_buf *buf, struct page **pages);
95
96u32 gss_krb5_unwrap_v2(struct krb5_ctx *kctx, int offset, int len,
97 struct xdr_buf *buf, unsigned int *slack,
98 unsigned int *align);
99
100/*
101 * Implementation internal functions
102 */
103
104/* Key Derivation Functions */
105
106int krb5_derive_key_v2(const struct gss_krb5_enctype *gk5e,
107 const struct xdr_netobj *inkey,
108 struct xdr_netobj *outkey,
109 const struct xdr_netobj *label,
110 gfp_t gfp_mask);
111
112int krb5_kdf_hmac_sha2(const struct gss_krb5_enctype *gk5e,
113 const struct xdr_netobj *inkey,
114 struct xdr_netobj *outkey,
115 const struct xdr_netobj *in_constant,
116 gfp_t gfp_mask);
117
118int krb5_kdf_feedback_cmac(const struct gss_krb5_enctype *gk5e,
119 const struct xdr_netobj *inkey,
120 struct xdr_netobj *outkey,
121 const struct xdr_netobj *in_constant,
122 gfp_t gfp_mask);
123
124/**
125 * krb5_derive_key - Derive a subkey from a protocol key
126 * @kctx: Kerberos 5 context
127 * @inkey: base protocol key
128 * @outkey: OUT: derived key
129 * @usage: key usage value
130 * @seed: key usage seed (one octet)
131 * @gfp_mask: memory allocation control flags
132 *
133 * Caller sets @outkey->len to the desired length of the derived key.
134 *
135 * On success, returns 0 and fills in @outkey. A negative errno value
136 * is returned on failure.
137 */
138static inline int krb5_derive_key(struct krb5_ctx *kctx,
139 const struct xdr_netobj *inkey,
140 struct xdr_netobj *outkey,
141 u32 usage, u8 seed, gfp_t gfp_mask)
142{
143 const struct gss_krb5_enctype *gk5e = kctx->gk5e;
144 u8 label_data[GSS_KRB5_K5CLENGTH];
145 struct xdr_netobj label = {
146 .len = sizeof(label_data),
147 .data = label_data,
148 };
149 __be32 *p = (__be32 *)label_data;
150
151 *p = cpu_to_be32(usage);
152 label_data[4] = seed;
153 return gk5e->derive_key(gk5e, inkey, outkey, &label, gfp_mask);
154}
155
156void krb5_make_confounder(u8 *p, int conflen);
157
158u32 gss_krb5_checksum(struct crypto_ahash *tfm, char *header, int hdrlen,
159 const struct xdr_buf *body, int body_offset,
160 struct xdr_netobj *cksumout);
161
162u32 krb5_encrypt(struct crypto_sync_skcipher *key, void *iv, void *in,
163 void *out, int length);
164
165int xdr_extend_head(struct xdr_buf *buf, unsigned int base,
166 unsigned int shiftlen);
167
168u32 gss_krb5_aes_encrypt(struct krb5_ctx *kctx, u32 offset,
169 struct xdr_buf *buf, struct page **pages);
170
171u32 gss_krb5_aes_decrypt(struct krb5_ctx *kctx, u32 offset, u32 len,
172 struct xdr_buf *buf, u32 *plainoffset, u32 *plainlen);
173
174u32 krb5_etm_encrypt(struct krb5_ctx *kctx, u32 offset, struct xdr_buf *buf,
175 struct page **pages);
176
177u32 krb5_etm_decrypt(struct krb5_ctx *kctx, u32 offset, u32 len,
178 struct xdr_buf *buf, u32 *headskip, u32 *tailskip);
179
180#if IS_ENABLED(CONFIG_KUNIT)
181void krb5_nfold(u32 inbits, const u8 *in, u32 outbits, u8 *out);
182const struct gss_krb5_enctype *gss_krb5_lookup_enctype(u32 etype);
183int krb5_cbc_cts_encrypt(struct crypto_sync_skcipher *cts_tfm,
184 struct crypto_sync_skcipher *cbc_tfm, u32 offset,
185 struct xdr_buf *buf, struct page **pages,
186 u8 *iv, unsigned int ivsize);
187int krb5_cbc_cts_decrypt(struct crypto_sync_skcipher *cts_tfm,
188 struct crypto_sync_skcipher *cbc_tfm,
189 u32 offset, struct xdr_buf *buf);
190u32 krb5_etm_checksum(struct crypto_sync_skcipher *cipher,
191 struct crypto_ahash *tfm, const struct xdr_buf *body,
192 int body_offset, struct xdr_netobj *cksumout);
193#endif
194
195#endif /* _NET_SUNRPC_AUTH_GSS_KRB5_INTERNAL_H */
196